Index: stable/9/sys/kern/vfs_bio.c =================================================================== --- stable/9/sys/kern/vfs_bio.c (revision 250946) +++ stable/9/sys/kern/vfs_bio.c (revision 250947) @@ -1,4169 +1,4167 @@ /*- * Copyright (c) 2004 Poul-Henning Kamp * Copyright (c) 1994,1997 John S. Dyson * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * this file contains a new buffer I/O scheme implementing a coherent * VM object and buffer cache scheme. Pains have been taken to make * sure that the performance degradation associated with schemes such * as this is not realized. * * Author: John S. Dyson * Significant help during the development and debugging phases * had been provided by David Greenman, also of the FreeBSD core team. * * see man buf(9) for more info. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "opt_compat.h" #include "opt_directio.h" #include "opt_swap.h" static MALLOC_DEFINE(M_BIOBUF, "biobuf", "BIO buffer"); struct bio_ops bioops; /* I/O operation notification */ struct buf_ops buf_ops_bio = { .bop_name = "buf_ops_bio", .bop_write = bufwrite, .bop_strategy = bufstrategy, .bop_sync = bufsync, .bop_bdflush = bufbdflush, }; /* * XXX buf is global because kern_shutdown.c and ffs_checkoverlap has * carnal knowledge of buffers. This knowledge should be moved to vfs_bio.c. */ struct buf *buf; /* buffer header pool */ static struct proc *bufdaemonproc; static int inmem(struct vnode *vp, daddr_t blkno); static void vm_hold_free_pages(struct buf *bp, int newbsize); static void vm_hold_load_pages(struct buf *bp, vm_offset_t from, vm_offset_t to); static void vfs_page_set_valid(struct buf *bp, vm_ooffset_t off, vm_page_t m); static void vfs_page_set_validclean(struct buf *bp, vm_ooffset_t off, vm_page_t m); static void vfs_drain_busy_pages(struct buf *bp); static void vfs_clean_pages_dirty_buf(struct buf *bp); static void vfs_setdirty_locked_object(struct buf *bp); static void vfs_vmio_release(struct buf *bp); static int vfs_bio_clcheck(struct vnode *vp, int size, daddr_t lblkno, daddr_t blkno); static int buf_do_flush(struct vnode *vp); static int flushbufqueues(struct vnode *, int, int); static void buf_daemon(void); static void bremfreel(struct buf *bp); #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) static int sysctl_bufspace(SYSCTL_HANDLER_ARGS); #endif int vmiodirenable = TRUE; SYSCTL_INT(_vfs, OID_AUTO, vmiodirenable, CTLFLAG_RW, &vmiodirenable, 0, "Use the VM system for directory writes"); long runningbufspace; SYSCTL_LONG(_vfs, OID_AUTO, runningbufspace, CTLFLAG_RD, &runningbufspace, 0, "Amount of presently outstanding async buffer io"); static long bufspace; #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) SYSCTL_PROC(_vfs, OID_AUTO, bufspace, CTLTYPE_LONG|CTLFLAG_MPSAFE|CTLFLAG_RD, &bufspace, 0, sysctl_bufspace, "L", "Virtual memory used for buffers"); #else SYSCTL_LONG(_vfs, OID_AUTO, bufspace, CTLFLAG_RD, &bufspace, 0, "Virtual memory used for buffers"); #endif static long maxbufspace; SYSCTL_LONG(_vfs, OID_AUTO, maxbufspace, CTLFLAG_RD, &maxbufspace, 0, "Maximum allowed value of bufspace (including buf_daemon)"); static long bufmallocspace; SYSCTL_LONG(_vfs, OID_AUTO, bufmallocspace, CTLFLAG_RD, &bufmallocspace, 0, "Amount of malloced memory for buffers"); static long maxbufmallocspace; SYSCTL_LONG(_vfs, OID_AUTO, maxmallocbufspace, CTLFLAG_RW, &maxbufmallocspace, 0, "Maximum amount of malloced memory for buffers"); static long lobufspace; SYSCTL_LONG(_vfs, OID_AUTO, lobufspace, CTLFLAG_RD, &lobufspace, 0, "Minimum amount of buffers we want to have"); long hibufspace; SYSCTL_LONG(_vfs, OID_AUTO, hibufspace, CTLFLAG_RD, &hibufspace, 0, "Maximum allowed value of bufspace (excluding buf_daemon)"); static int bufreusecnt; SYSCTL_INT(_vfs, OID_AUTO, bufreusecnt, CTLFLAG_RW, &bufreusecnt, 0, "Number of times we have reused a buffer"); static int buffreekvacnt; SYSCTL_INT(_vfs, OID_AUTO, buffreekvacnt, CTLFLAG_RW, &buffreekvacnt, 0, "Number of times we have freed the KVA space from some buffer"); static int bufdefragcnt; SYSCTL_INT(_vfs, OID_AUTO, bufdefragcnt, CTLFLAG_RW, &bufdefragcnt, 0, "Number of times we have had to repeat buffer allocation to defragment"); static long lorunningspace; SYSCTL_LONG(_vfs, OID_AUTO, lorunningspace, CTLFLAG_RW, &lorunningspace, 0, "Minimum preferred space used for in-progress I/O"); static long hirunningspace; SYSCTL_LONG(_vfs, OID_AUTO, hirunningspace, CTLFLAG_RW, &hirunningspace, 0, "Maximum amount of space to use for in-progress I/O"); int dirtybufferflushes; SYSCTL_INT(_vfs, OID_AUTO, dirtybufferflushes, CTLFLAG_RW, &dirtybufferflushes, 0, "Number of bdwrite to bawrite conversions to limit dirty buffers"); int bdwriteskip; SYSCTL_INT(_vfs, OID_AUTO, bdwriteskip, CTLFLAG_RW, &bdwriteskip, 0, "Number of buffers supplied to bdwrite with snapshot deadlock risk"); int altbufferflushes; SYSCTL_INT(_vfs, OID_AUTO, altbufferflushes, CTLFLAG_RW, &altbufferflushes, 0, "Number of fsync flushes to limit dirty buffers"); static int recursiveflushes; SYSCTL_INT(_vfs, OID_AUTO, recursiveflushes, CTLFLAG_RW, &recursiveflushes, 0, "Number of flushes skipped due to being recursive"); static int numdirtybuffers; SYSCTL_INT(_vfs, OID_AUTO, numdirtybuffers, CTLFLAG_RD, &numdirtybuffers, 0, "Number of buffers that are dirty (has unwritten changes) at the moment"); static int lodirtybuffers; SYSCTL_INT(_vfs, OID_AUTO, lodirtybuffers, CTLFLAG_RW, &lodirtybuffers, 0, "How many buffers we want to have free before bufdaemon can sleep"); static int hidirtybuffers; SYSCTL_INT(_vfs, OID_AUTO, hidirtybuffers, CTLFLAG_RW, &hidirtybuffers, 0, "When the number of dirty buffers is considered severe"); int dirtybufthresh; SYSCTL_INT(_vfs, OID_AUTO, dirtybufthresh, CTLFLAG_RW, &dirtybufthresh, 0, "Number of bdwrite to bawrite conversions to clear dirty buffers"); static int numfreebuffers; SYSCTL_INT(_vfs, OID_AUTO, numfreebuffers, CTLFLAG_RD, &numfreebuffers, 0, "Number of free buffers"); static int lofreebuffers; SYSCTL_INT(_vfs, OID_AUTO, lofreebuffers, CTLFLAG_RW, &lofreebuffers, 0, "XXX Unused"); static int hifreebuffers; SYSCTL_INT(_vfs, OID_AUTO, hifreebuffers, CTLFLAG_RW, &hifreebuffers, 0, "XXX Complicatedly unused"); static int getnewbufcalls; SYSCTL_INT(_vfs, OID_AUTO, getnewbufcalls, CTLFLAG_RW, &getnewbufcalls, 0, "Number of calls to getnewbuf"); static int getnewbufrestarts; SYSCTL_INT(_vfs, OID_AUTO, getnewbufrestarts, CTLFLAG_RW, &getnewbufrestarts, 0, "Number of times getnewbuf has had to restart a buffer aquisition"); static int flushbufqtarget = 100; SYSCTL_INT(_vfs, OID_AUTO, flushbufqtarget, CTLFLAG_RW, &flushbufqtarget, 0, "Amount of work to do in flushbufqueues when helping bufdaemon"); static long notbufdflashes; SYSCTL_LONG(_vfs, OID_AUTO, notbufdflashes, CTLFLAG_RD, ¬bufdflashes, 0, "Number of dirty buffer flushes done by the bufdaemon helpers"); static long barrierwrites; SYSCTL_LONG(_vfs, OID_AUTO, barrierwrites, CTLFLAG_RW, &barrierwrites, 0, "Number of barrier writes"); /* * Wakeup point for bufdaemon, as well as indicator of whether it is already * active. Set to 1 when the bufdaemon is already "on" the queue, 0 when it * is idling. */ static int bd_request; /* * Request for the buf daemon to write more buffers than is indicated by * lodirtybuf. This may be necessary to push out excess dependencies or * defragment the address space where a simple count of the number of dirty * buffers is insufficient to characterize the demand for flushing them. */ static int bd_speedupreq; /* * This lock synchronizes access to bd_request. */ static struct mtx bdlock; /* * bogus page -- for I/O to/from partially complete buffers * this is a temporary solution to the problem, but it is not * really that bad. it would be better to split the buffer * for input in the case of buffers partially already in memory, * but the code is intricate enough already. */ vm_page_t bogus_page; /* * Synchronization (sleep/wakeup) variable for active buffer space requests. * Set when wait starts, cleared prior to wakeup(). * Used in runningbufwakeup() and waitrunningbufspace(). */ static int runningbufreq; /* * This lock protects the runningbufreq and synchronizes runningbufwakeup and * waitrunningbufspace(). */ static struct mtx rbreqlock; /* * Synchronization (sleep/wakeup) variable for buffer requests. * Can contain the VFS_BIO_NEED flags defined below; setting/clearing is done * by and/or. * Used in numdirtywakeup(), bufspacewakeup(), bufcountwakeup(), bwillwrite(), * getnewbuf(), and getblk(). */ static int needsbuffer; /* * Lock that protects needsbuffer and the sleeps/wakeups surrounding it. */ static struct mtx nblock; /* * Definitions for the buffer free lists. */ #define BUFFER_QUEUES 6 /* number of free buffer queues */ #define QUEUE_NONE 0 /* on no queue */ #define QUEUE_CLEAN 1 /* non-B_DELWRI buffers */ #define QUEUE_DIRTY 2 /* B_DELWRI buffers */ #define QUEUE_DIRTY_GIANT 3 /* B_DELWRI buffers that need giant */ #define QUEUE_EMPTYKVA 4 /* empty buffer headers w/KVA assignment */ #define QUEUE_EMPTY 5 /* empty buffer headers */ #define QUEUE_SENTINEL 1024 /* not an queue index, but mark for sentinel */ /* Queues for free buffers with various properties */ static TAILQ_HEAD(bqueues, buf) bufqueues[BUFFER_QUEUES] = { { 0 } }; /* Lock for the bufqueues */ static struct mtx bqlock; /* * Single global constant for BUF_WMESG, to avoid getting multiple references. * buf_wmesg is referred from macros. */ const char *buf_wmesg = BUF_WMESG; #define VFS_BIO_NEED_ANY 0x01 /* any freeable buffer */ #define VFS_BIO_NEED_DIRTYFLUSH 0x02 /* waiting for dirty buffer flush */ #define VFS_BIO_NEED_FREE 0x04 /* wait for free bufs, hi hysteresis */ #define VFS_BIO_NEED_BUFSPACE 0x08 /* wait for buf space, lo hysteresis */ #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) static int sysctl_bufspace(SYSCTL_HANDLER_ARGS) { long lvalue; int ivalue; if (sizeof(int) == sizeof(long) || req->oldlen >= sizeof(long)) return (sysctl_handle_long(oidp, arg1, arg2, req)); lvalue = *(long *)arg1; if (lvalue > INT_MAX) /* On overflow, still write out a long to trigger ENOMEM. */ return (sysctl_handle_long(oidp, &lvalue, 0, req)); ivalue = lvalue; return (sysctl_handle_int(oidp, &ivalue, 0, req)); } #endif #ifdef DIRECTIO extern void ffs_rawread_setup(void); #endif /* DIRECTIO */ /* * numdirtywakeup: * * If someone is blocked due to there being too many dirty buffers, * and numdirtybuffers is now reasonable, wake them up. */ static __inline void numdirtywakeup(int level) { if (numdirtybuffers <= level) { mtx_lock(&nblock); if (needsbuffer & VFS_BIO_NEED_DIRTYFLUSH) { needsbuffer &= ~VFS_BIO_NEED_DIRTYFLUSH; wakeup(&needsbuffer); } mtx_unlock(&nblock); } } /* * bufspacewakeup: * * Called when buffer space is potentially available for recovery. * getnewbuf() will block on this flag when it is unable to free * sufficient buffer space. Buffer space becomes recoverable when * bp's get placed back in the queues. */ static __inline void bufspacewakeup(void) { /* * If someone is waiting for BUF space, wake them up. Even * though we haven't freed the kva space yet, the waiting * process will be able to now. */ mtx_lock(&nblock); if (needsbuffer & VFS_BIO_NEED_BUFSPACE) { needsbuffer &= ~VFS_BIO_NEED_BUFSPACE; wakeup(&needsbuffer); } mtx_unlock(&nblock); } /* * runningbufwakeup() - in-progress I/O accounting. * */ void runningbufwakeup(struct buf *bp) { if (bp->b_runningbufspace) { atomic_subtract_long(&runningbufspace, bp->b_runningbufspace); bp->b_runningbufspace = 0; mtx_lock(&rbreqlock); if (runningbufreq && runningbufspace <= lorunningspace) { runningbufreq = 0; wakeup(&runningbufreq); } mtx_unlock(&rbreqlock); } } /* * bufcountwakeup: * * Called when a buffer has been added to one of the free queues to * account for the buffer and to wakeup anyone waiting for free buffers. * This typically occurs when large amounts of metadata are being handled * by the buffer cache ( else buffer space runs out first, usually ). */ static __inline void bufcountwakeup(struct buf *bp) { int old; KASSERT((bp->b_vflags & BV_INFREECNT) == 0, ("buf %p already counted as free", bp)); if (bp->b_bufobj != NULL) mtx_assert(BO_MTX(bp->b_bufobj), MA_OWNED); bp->b_vflags |= BV_INFREECNT; old = atomic_fetchadd_int(&numfreebuffers, 1); KASSERT(old >= 0 && old < nbuf, ("numfreebuffers climbed to %d", old + 1)); mtx_lock(&nblock); if (needsbuffer) { needsbuffer &= ~VFS_BIO_NEED_ANY; if (numfreebuffers >= hifreebuffers) needsbuffer &= ~VFS_BIO_NEED_FREE; wakeup(&needsbuffer); } mtx_unlock(&nblock); } /* * waitrunningbufspace() * * runningbufspace is a measure of the amount of I/O currently * running. This routine is used in async-write situations to * prevent creating huge backups of pending writes to a device. * Only asynchronous writes are governed by this function. * * Reads will adjust runningbufspace, but will not block based on it. * The read load has a side effect of reducing the allowed write load. * * This does NOT turn an async write into a sync write. It waits * for earlier writes to complete and generally returns before the * caller's write has reached the device. */ void waitrunningbufspace(void) { mtx_lock(&rbreqlock); while (runningbufspace > hirunningspace) { ++runningbufreq; msleep(&runningbufreq, &rbreqlock, PVM, "wdrain", 0); } mtx_unlock(&rbreqlock); } /* * vfs_buf_test_cache: * * Called when a buffer is extended. This function clears the B_CACHE * bit if the newly extended portion of the buffer does not contain * valid data. */ static __inline void vfs_buf_test_cache(struct buf *bp, vm_ooffset_t foff, vm_offset_t off, vm_offset_t size, vm_page_t m) { VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED); if (bp->b_flags & B_CACHE) { int base = (foff + off) & PAGE_MASK; if (vm_page_is_valid(m, base, size) == 0) bp->b_flags &= ~B_CACHE; } } /* Wake up the buffer daemon if necessary */ static __inline void bd_wakeup(int dirtybuflevel) { mtx_lock(&bdlock); if (bd_request == 0 && numdirtybuffers >= dirtybuflevel) { bd_request = 1; wakeup(&bd_request); } mtx_unlock(&bdlock); } /* * bd_speedup - speedup the buffer cache flushing code */ void bd_speedup(void) { int needwake; mtx_lock(&bdlock); needwake = 0; if (bd_speedupreq == 0 || bd_request == 0) needwake = 1; bd_speedupreq = 1; bd_request = 1; if (needwake) wakeup(&bd_request); mtx_unlock(&bdlock); } /* * Calculating buffer cache scaling values and reserve space for buffer * headers. This is called during low level kernel initialization and * may be called more then once. We CANNOT write to the memory area * being reserved at this time. */ caddr_t kern_vfs_bio_buffer_alloc(caddr_t v, long physmem_est) { int tuned_nbuf; long maxbuf; /* * physmem_est is in pages. Convert it to kilobytes (assumes * PAGE_SIZE is >= 1K) */ physmem_est = physmem_est * (PAGE_SIZE / 1024); /* * The nominal buffer size (and minimum KVA allocation) is BKVASIZE. * For the first 64MB of ram nominally allocate sufficient buffers to * cover 1/4 of our ram. Beyond the first 64MB allocate additional * buffers to cover 1/10 of our ram over 64MB. When auto-sizing * the buffer cache we limit the eventual kva reservation to * maxbcache bytes. * * factor represents the 1/4 x ram conversion. */ if (nbuf == 0) { int factor = 4 * BKVASIZE / 1024; nbuf = 50; if (physmem_est > 4096) nbuf += min((physmem_est - 4096) / factor, 65536 / factor); if (physmem_est > 65536) nbuf += (physmem_est - 65536) * 2 / (factor * 5); if (maxbcache && nbuf > maxbcache / BKVASIZE) nbuf = maxbcache / BKVASIZE; tuned_nbuf = 1; } else tuned_nbuf = 0; /* XXX Avoid unsigned long overflows later on with maxbufspace. */ maxbuf = (LONG_MAX / 3) / BKVASIZE; if (nbuf > maxbuf) { if (!tuned_nbuf) printf("Warning: nbufs lowered from %d to %ld\n", nbuf, maxbuf); nbuf = maxbuf; } /* * swbufs are used as temporary holders for I/O, such as paging I/O. * We have no less then 16 and no more then 256. */ nswbuf = max(min(nbuf/4, 256), 16); #ifdef NSWBUF_MIN if (nswbuf < NSWBUF_MIN) nswbuf = NSWBUF_MIN; #endif #ifdef DIRECTIO ffs_rawread_setup(); #endif /* * Reserve space for the buffer cache buffers */ swbuf = (void *)v; v = (caddr_t)(swbuf + nswbuf); buf = (void *)v; v = (caddr_t)(buf + nbuf); return(v); } /* Initialize the buffer subsystem. Called before use of any buffers. */ void bufinit(void) { struct buf *bp; int i; mtx_init(&bqlock, "buf queue lock", NULL, MTX_DEF); mtx_init(&rbreqlock, "runningbufspace lock", NULL, MTX_DEF); mtx_init(&nblock, "needsbuffer lock", NULL, MTX_DEF); mtx_init(&bdlock, "buffer daemon lock", NULL, MTX_DEF); /* next, make a null set of free lists */ for (i = 0; i < BUFFER_QUEUES; i++) TAILQ_INIT(&bufqueues[i]); /* finally, initialize each buffer header and stick on empty q */ for (i = 0; i < nbuf; i++) { bp = &buf[i]; bzero(bp, sizeof *bp); bp->b_flags = B_INVAL; /* we're just an empty header */ bp->b_rcred = NOCRED; bp->b_wcred = NOCRED; bp->b_qindex = QUEUE_EMPTY; bp->b_vflags = BV_INFREECNT; /* buf is counted as free */ bp->b_xflags = 0; LIST_INIT(&bp->b_dep); BUF_LOCKINIT(bp); TAILQ_INSERT_TAIL(&bufqueues[QUEUE_EMPTY], bp, b_freelist); } /* * maxbufspace is the absolute maximum amount of buffer space we are * allowed to reserve in KVM and in real terms. The absolute maximum * is nominally used by buf_daemon. hibufspace is the nominal maximum * used by most other processes. The differential is required to * ensure that buf_daemon is able to run when other processes might * be blocked waiting for buffer space. * * maxbufspace is based on BKVASIZE. Allocating buffers larger then * this may result in KVM fragmentation which is not handled optimally * by the system. */ maxbufspace = (long)nbuf * BKVASIZE; hibufspace = lmax(3 * maxbufspace / 4, maxbufspace - MAXBSIZE * 10); lobufspace = hibufspace - MAXBSIZE; /* * Note: The 16 MiB upper limit for hirunningspace was chosen * arbitrarily and may need further tuning. It corresponds to * 128 outstanding write IO requests (if IO size is 128 KiB), * which fits with many RAID controllers' tagged queuing limits. * The lower 1 MiB limit is the historical upper limit for * hirunningspace. */ hirunningspace = lmax(lmin(roundup(hibufspace / 64, MAXBSIZE), 16 * 1024 * 1024), 1024 * 1024); lorunningspace = roundup((hirunningspace * 2) / 3, MAXBSIZE); /* * Limit the amount of malloc memory since it is wired permanently into * the kernel space. Even though this is accounted for in the buffer * allocation, we don't want the malloced region to grow uncontrolled. * The malloc scheme improves memory utilization significantly on average * (small) directories. */ maxbufmallocspace = hibufspace / 20; /* * Reduce the chance of a deadlock occuring by limiting the number * of delayed-write dirty buffers we allow to stack up. */ hidirtybuffers = nbuf / 4 + 20; dirtybufthresh = hidirtybuffers * 9 / 10; numdirtybuffers = 0; /* * To support extreme low-memory systems, make sure hidirtybuffers cannot * eat up all available buffer space. This occurs when our minimum cannot * be met. We try to size hidirtybuffers to 3/4 our buffer space assuming * BKVASIZE'd buffers. */ while ((long)hidirtybuffers * BKVASIZE > 3 * hibufspace / 4) { hidirtybuffers >>= 1; } lodirtybuffers = hidirtybuffers / 2; /* * Try to keep the number of free buffers in the specified range, * and give special processes (e.g. like buf_daemon) access to an * emergency reserve. */ lofreebuffers = nbuf / 18 + 5; hifreebuffers = 2 * lofreebuffers; numfreebuffers = nbuf; bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ | VM_ALLOC_NORMAL | VM_ALLOC_WIRED); } /* * bfreekva() - free the kva allocation for a buffer. * * Since this call frees up buffer space, we call bufspacewakeup(). */ static void bfreekva(struct buf *bp) { if (bp->b_kvasize) { atomic_add_int(&buffreekvacnt, 1); atomic_subtract_long(&bufspace, bp->b_kvasize); vm_map_remove(buffer_map, (vm_offset_t) bp->b_kvabase, (vm_offset_t) bp->b_kvabase + bp->b_kvasize); bp->b_kvasize = 0; bufspacewakeup(); } } /* * bremfree: * * Mark the buffer for removal from the appropriate free list in brelse. * */ void bremfree(struct buf *bp) { int old; CTR3(KTR_BUF, "bremfree(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); KASSERT((bp->b_flags & B_REMFREE) == 0, ("bremfree: buffer %p already marked for delayed removal.", bp)); KASSERT(bp->b_qindex != QUEUE_NONE, ("bremfree: buffer %p not on a queue.", bp)); BUF_ASSERT_HELD(bp); bp->b_flags |= B_REMFREE; /* Fixup numfreebuffers count. */ if ((bp->b_flags & B_INVAL) || (bp->b_flags & B_DELWRI) == 0) { KASSERT((bp->b_vflags & BV_INFREECNT) != 0, ("buf %p not counted in numfreebuffers", bp)); if (bp->b_bufobj != NULL) mtx_assert(BO_MTX(bp->b_bufobj), MA_OWNED); bp->b_vflags &= ~BV_INFREECNT; old = atomic_fetchadd_int(&numfreebuffers, -1); KASSERT(old > 0, ("numfreebuffers dropped to %d", old - 1)); } } /* * bremfreef: * * Force an immediate removal from a free list. Used only in nfs when * it abuses the b_freelist pointer. */ void bremfreef(struct buf *bp) { mtx_lock(&bqlock); bremfreel(bp); mtx_unlock(&bqlock); } /* * bremfreel: * * Removes a buffer from the free list, must be called with the * bqlock held. */ static void bremfreel(struct buf *bp) { int old; CTR3(KTR_BUF, "bremfreel(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); KASSERT(bp->b_qindex != QUEUE_NONE, ("bremfreel: buffer %p not on a queue.", bp)); BUF_ASSERT_HELD(bp); mtx_assert(&bqlock, MA_OWNED); TAILQ_REMOVE(&bufqueues[bp->b_qindex], bp, b_freelist); bp->b_qindex = QUEUE_NONE; /* * If this was a delayed bremfree() we only need to remove the buffer * from the queue and return the stats are already done. */ if (bp->b_flags & B_REMFREE) { bp->b_flags &= ~B_REMFREE; return; } /* * Fixup numfreebuffers count. If the buffer is invalid or not * delayed-write, the buffer was free and we must decrement * numfreebuffers. */ if ((bp->b_flags & B_INVAL) || (bp->b_flags & B_DELWRI) == 0) { KASSERT((bp->b_vflags & BV_INFREECNT) != 0, ("buf %p not counted in numfreebuffers", bp)); if (bp->b_bufobj != NULL) mtx_assert(BO_MTX(bp->b_bufobj), MA_OWNED); bp->b_vflags &= ~BV_INFREECNT; old = atomic_fetchadd_int(&numfreebuffers, -1); KASSERT(old > 0, ("numfreebuffers dropped to %d", old - 1)); } } /* * Get a buffer with the specified data. */ int bread(struct vnode * vp, daddr_t blkno, int size, struct ucred * cred, struct buf **bpp) { return (breadn_flags(vp, blkno, size, 0, 0, 0, cred, 0, bpp)); } /* * Attempt to initiate asynchronous I/O on read-ahead blocks. We must * clear BIO_ERROR and B_INVAL prior to initiating I/O . If B_CACHE is set, * the buffer is valid and we do not have to do anything. */ void breada(struct vnode * vp, daddr_t * rablkno, int * rabsize, int cnt, struct ucred * cred) { struct buf *rabp; int i; for (i = 0; i < cnt; i++, rablkno++, rabsize++) { if (inmem(vp, *rablkno)) continue; rabp = getblk(vp, *rablkno, *rabsize, 0, 0, 0); if ((rabp->b_flags & B_CACHE) == 0) { if (!TD_IS_IDLETHREAD(curthread)) curthread->td_ru.ru_inblock++; rabp->b_flags |= B_ASYNC; rabp->b_flags &= ~B_INVAL; rabp->b_ioflags &= ~BIO_ERROR; rabp->b_iocmd = BIO_READ; if (rabp->b_rcred == NOCRED && cred != NOCRED) rabp->b_rcred = crhold(cred); vfs_busy_pages(rabp, 0); BUF_KERNPROC(rabp); rabp->b_iooffset = dbtob(rabp->b_blkno); bstrategy(rabp); } else { brelse(rabp); } } } /* * Operates like bread, but also starts asynchronous I/O on * read-ahead blocks. */ int breadn(struct vnode * vp, daddr_t blkno, int size, daddr_t * rablkno, int *rabsize, int cnt, struct ucred * cred, struct buf **bpp) { return (breadn_flags(vp, blkno, size, rablkno, rabsize, cnt, cred, 0, bpp)); } /* * Entry point for bread() and breadn(). * * Get a buffer with the specified data. Look in the cache first. We * must clear BIO_ERROR and B_INVAL prior to initiating I/O. If B_CACHE * is set, the buffer is valid and we do not have to do anything, see * getblk(). Also starts asynchronous I/O on read-ahead blocks. */ int -breadn_flags(struct vnode * vp, daddr_t blkno, int size, - daddr_t * rablkno, int *rabsize, int cnt, - struct ucred * cred, int flags, struct buf **bpp) +breadn_flags(struct vnode *vp, daddr_t blkno, int size, daddr_t *rablkno, + int *rabsize, int cnt, struct ucred *cred, int flags, struct buf **bpp) { struct buf *bp; int rv = 0, readwait = 0; CTR3(KTR_BUF, "breadn(%p, %jd, %d)", vp, blkno, size); /* * Can only return NULL if GB_LOCK_NOWAIT flag is specified. */ *bpp = bp = getblk(vp, blkno, size, 0, 0, flags); if (bp == NULL) return (EBUSY); /* if not found in cache, do some I/O */ if ((bp->b_flags & B_CACHE) == 0) { if (!TD_IS_IDLETHREAD(curthread)) curthread->td_ru.ru_inblock++; bp->b_iocmd = BIO_READ; bp->b_flags &= ~B_INVAL; bp->b_ioflags &= ~BIO_ERROR; if (bp->b_rcred == NOCRED && cred != NOCRED) bp->b_rcred = crhold(cred); vfs_busy_pages(bp, 0); bp->b_iooffset = dbtob(bp->b_blkno); bstrategy(bp); ++readwait; } breada(vp, rablkno, rabsize, cnt, cred); if (readwait) { rv = bufwait(bp); } return (rv); } /* * Write, release buffer on completion. (Done by iodone * if async). Do not bother writing anything if the buffer * is invalid. * * Note that we set B_CACHE here, indicating that buffer is * fully valid and thus cacheable. This is true even of NFS * now so we set it generally. This could be set either here * or in biodone() since the I/O is synchronous. We put it * here. */ int bufwrite(struct buf *bp) { int oldflags; struct vnode *vp; int vp_md; CTR3(KTR_BUF, "bufwrite(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); if (bp->b_flags & B_INVAL) { brelse(bp); return (0); } if (bp->b_flags & B_BARRIER) barrierwrites++; oldflags = bp->b_flags; BUF_ASSERT_HELD(bp); if (bp->b_pin_count > 0) bunpin_wait(bp); KASSERT(!(bp->b_vflags & BV_BKGRDINPROG), ("FFS background buffer should not get here %p", bp)); vp = bp->b_vp; if (vp) vp_md = vp->v_vflag & VV_MD; else vp_md = 0; /* * Mark the buffer clean. Increment the bufobj write count * before bundirty() call, to prevent other thread from seeing * empty dirty list and zero counter for writes in progress, * falsely indicating that the bufobj is clean. */ bufobj_wref(bp->b_bufobj); bundirty(bp); bp->b_flags &= ~B_DONE; bp->b_ioflags &= ~BIO_ERROR; bp->b_flags |= B_CACHE; bp->b_iocmd = BIO_WRITE; vfs_busy_pages(bp, 1); /* * Normal bwrites pipeline writes */ bp->b_runningbufspace = bp->b_bufsize; atomic_add_long(&runningbufspace, bp->b_runningbufspace); if (!TD_IS_IDLETHREAD(curthread)) curthread->td_ru.ru_oublock++; if (oldflags & B_ASYNC) BUF_KERNPROC(bp); bp->b_iooffset = dbtob(bp->b_blkno); bstrategy(bp); if ((oldflags & B_ASYNC) == 0) { int rtval = bufwait(bp); brelse(bp); return (rtval); } else { /* * don't allow the async write to saturate the I/O * system. We will not deadlock here because * we are blocking waiting for I/O that is already in-progress * to complete. We do not block here if it is the update * or syncer daemon trying to clean up as that can lead * to deadlock. */ if ((curthread->td_pflags & TDP_NORUNNINGBUF) == 0 && !vp_md) waitrunningbufspace(); } return (0); } void bufbdflush(struct bufobj *bo, struct buf *bp) { struct buf *nbp; if (bo->bo_dirty.bv_cnt > dirtybufthresh + 10) { (void) VOP_FSYNC(bp->b_vp, MNT_NOWAIT, curthread); altbufferflushes++; } else if (bo->bo_dirty.bv_cnt > dirtybufthresh) { BO_LOCK(bo); /* * Try to find a buffer to flush. */ TAILQ_FOREACH(nbp, &bo->bo_dirty.bv_hd, b_bobufs) { if ((nbp->b_vflags & BV_BKGRDINPROG) || BUF_LOCK(nbp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) continue; if (bp == nbp) panic("bdwrite: found ourselves"); BO_UNLOCK(bo); /* Don't countdeps with the bo lock held. */ if (buf_countdeps(nbp, 0)) { BO_LOCK(bo); BUF_UNLOCK(nbp); continue; } if (nbp->b_flags & B_CLUSTEROK) { vfs_bio_awrite(nbp); } else { bremfree(nbp); bawrite(nbp); } dirtybufferflushes++; break; } if (nbp == NULL) BO_UNLOCK(bo); } } /* * Delayed write. (Buffer is marked dirty). Do not bother writing * anything if the buffer is marked invalid. * * Note that since the buffer must be completely valid, we can safely * set B_CACHE. In fact, we have to set B_CACHE here rather then in * biodone() in order to prevent getblk from writing the buffer * out synchronously. */ void bdwrite(struct buf *bp) { struct thread *td = curthread; struct vnode *vp; struct bufobj *bo; CTR3(KTR_BUF, "bdwrite(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); KASSERT((bp->b_flags & B_BARRIER) == 0, ("Barrier request in delayed write %p", bp)); BUF_ASSERT_HELD(bp); if (bp->b_flags & B_INVAL) { brelse(bp); return; } /* * If we have too many dirty buffers, don't create any more. * If we are wildly over our limit, then force a complete * cleanup. Otherwise, just keep the situation from getting * out of control. Note that we have to avoid a recursive * disaster and not try to clean up after our own cleanup! */ vp = bp->b_vp; bo = bp->b_bufobj; if ((td->td_pflags & (TDP_COWINPROGRESS|TDP_INBDFLUSH)) == 0) { td->td_pflags |= TDP_INBDFLUSH; BO_BDFLUSH(bo, bp); td->td_pflags &= ~TDP_INBDFLUSH; } else recursiveflushes++; bdirty(bp); /* * Set B_CACHE, indicating that the buffer is fully valid. This is * true even of NFS now. */ bp->b_flags |= B_CACHE; /* * This bmap keeps the system from needing to do the bmap later, * perhaps when the system is attempting to do a sync. Since it * is likely that the indirect block -- or whatever other datastructure * that the filesystem needs is still in memory now, it is a good * thing to do this. Note also, that if the pageout daemon is * requesting a sync -- there might not be enough memory to do * the bmap then... So, this is important to do. */ if (vp->v_type != VCHR && bp->b_lblkno == bp->b_blkno) { VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL, NULL); } /* * Set the *dirty* buffer range based upon the VM system dirty * pages. * * Mark the buffer pages as clean. We need to do this here to * satisfy the vnode_pager and the pageout daemon, so that it * thinks that the pages have been "cleaned". Note that since * the pages are in a delayed write buffer -- the VFS layer * "will" see that the pages get written out on the next sync, * or perhaps the cluster will be completed. */ vfs_clean_pages_dirty_buf(bp); bqrelse(bp); /* * Wakeup the buffer flushing daemon if we have a lot of dirty * buffers (midpoint between our recovery point and our stall * point). */ bd_wakeup((lodirtybuffers + hidirtybuffers) / 2); /* * note: we cannot initiate I/O from a bdwrite even if we wanted to, * due to the softdep code. */ } /* * bdirty: * * Turn buffer into delayed write request. We must clear BIO_READ and * B_RELBUF, and we must set B_DELWRI. We reassign the buffer to * itself to properly update it in the dirty/clean lists. We mark it * B_DONE to ensure that any asynchronization of the buffer properly * clears B_DONE ( else a panic will occur later ). * * bdirty() is kinda like bdwrite() - we have to clear B_INVAL which * might have been set pre-getblk(). Unlike bwrite/bdwrite, bdirty() * should only be called if the buffer is known-good. * * Since the buffer is not on a queue, we do not update the numfreebuffers * count. * * The buffer must be on QUEUE_NONE. */ void bdirty(struct buf *bp) { CTR3(KTR_BUF, "bdirty(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); KASSERT(bp->b_flags & B_REMFREE || bp->b_qindex == QUEUE_NONE, ("bdirty: buffer %p still on queue %d", bp, bp->b_qindex)); BUF_ASSERT_HELD(bp); bp->b_flags &= ~(B_RELBUF); bp->b_iocmd = BIO_WRITE; if ((bp->b_flags & B_DELWRI) == 0) { bp->b_flags |= /* XXX B_DONE | */ B_DELWRI; reassignbuf(bp); atomic_add_int(&numdirtybuffers, 1); bd_wakeup((lodirtybuffers + hidirtybuffers) / 2); } } /* * bundirty: * * Clear B_DELWRI for buffer. * * Since the buffer is not on a queue, we do not update the numfreebuffers * count. * * The buffer must be on QUEUE_NONE. */ void bundirty(struct buf *bp) { CTR3(KTR_BUF, "bundirty(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); KASSERT(bp->b_bufobj != NULL, ("No b_bufobj %p", bp)); KASSERT(bp->b_flags & B_REMFREE || bp->b_qindex == QUEUE_NONE, ("bundirty: buffer %p still on queue %d", bp, bp->b_qindex)); BUF_ASSERT_HELD(bp); if (bp->b_flags & B_DELWRI) { bp->b_flags &= ~B_DELWRI; reassignbuf(bp); atomic_subtract_int(&numdirtybuffers, 1); numdirtywakeup(lodirtybuffers); } /* * Since it is now being written, we can clear its deferred write flag. */ bp->b_flags &= ~B_DEFERRED; } /* * bawrite: * * Asynchronous write. Start output on a buffer, but do not wait for * it to complete. The buffer is released when the output completes. * * bwrite() ( or the VOP routine anyway ) is responsible for handling * B_INVAL buffers. Not us. */ void bawrite(struct buf *bp) { bp->b_flags |= B_ASYNC; (void) bwrite(bp); } /* * babarrierwrite: * * Asynchronous barrier write. Start output on a buffer, but do not * wait for it to complete. Place a write barrier after this write so * that this buffer and all buffers written before it are committed to * the disk before any buffers written after this write are committed * to the disk. The buffer is released when the output completes. */ void babarrierwrite(struct buf *bp) { bp->b_flags |= B_ASYNC | B_BARRIER; (void) bwrite(bp); } /* * bbarrierwrite: * * Synchronous barrier write. Start output on a buffer and wait for * it to complete. Place a write barrier after this write so that * this buffer and all buffers written before it are committed to * the disk before any buffers written after this write are committed * to the disk. The buffer is released when the output completes. */ int bbarrierwrite(struct buf *bp) { bp->b_flags |= B_BARRIER; return (bwrite(bp)); } /* * bwillwrite: * * Called prior to the locking of any vnodes when we are expecting to * write. We do not want to starve the buffer cache with too many * dirty buffers so we block here. By blocking prior to the locking * of any vnodes we attempt to avoid the situation where a locked vnode * prevents the various system daemons from flushing related buffers. */ void bwillwrite(void) { if (numdirtybuffers >= hidirtybuffers) { mtx_lock(&nblock); while (numdirtybuffers >= hidirtybuffers) { bd_wakeup(1); needsbuffer |= VFS_BIO_NEED_DIRTYFLUSH; msleep(&needsbuffer, &nblock, (PRIBIO + 4), "flswai", 0); } mtx_unlock(&nblock); } } /* * Return true if we have too many dirty buffers. */ int buf_dirty_count_severe(void) { return(numdirtybuffers >= hidirtybuffers); } static __noinline int buf_vm_page_count_severe(void) { KFAIL_POINT_CODE(DEBUG_FP, buf_pressure, return 1); return vm_page_count_severe(); } /* * brelse: * * Release a busy buffer and, if requested, free its resources. The * buffer will be stashed in the appropriate bufqueue[] allowing it * to be accessed later as a cache entity or reused for other purposes. */ void brelse(struct buf *bp) { CTR3(KTR_BUF, "brelse(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); KASSERT(!(bp->b_flags & (B_CLUSTER|B_PAGING)), ("brelse: inappropriate B_PAGING or B_CLUSTER bp %p", bp)); if (BUF_LOCKRECURSED(bp)) { /* * Do not process, in particular, do not handle the * B_INVAL/B_RELBUF and do not release to free list. */ BUF_UNLOCK(bp); return; } if (bp->b_flags & B_MANAGED) { bqrelse(bp); return; } if (bp->b_iocmd == BIO_WRITE && (bp->b_ioflags & BIO_ERROR) && bp->b_error == EIO && !(bp->b_flags & B_INVAL)) { /* * Failed write, redirty. Must clear BIO_ERROR to prevent * pages from being scrapped. If the error is anything * other than an I/O error (EIO), assume that retrying * is futile. */ bp->b_ioflags &= ~BIO_ERROR; bdirty(bp); } else if ((bp->b_flags & (B_NOCACHE | B_INVAL)) || (bp->b_ioflags & BIO_ERROR) || (bp->b_bufsize <= 0)) { /* * Either a failed I/O or we were asked to free or not * cache the buffer. */ bp->b_flags |= B_INVAL; if (!LIST_EMPTY(&bp->b_dep)) buf_deallocate(bp); if (bp->b_flags & B_DELWRI) { atomic_subtract_int(&numdirtybuffers, 1); numdirtywakeup(lodirtybuffers); } bp->b_flags &= ~(B_DELWRI | B_CACHE); if ((bp->b_flags & B_VMIO) == 0) { if (bp->b_bufsize) allocbuf(bp, 0); if (bp->b_vp) brelvp(bp); } } /* * We must clear B_RELBUF if B_DELWRI is set. If vfs_vmio_release() * is called with B_DELWRI set, the underlying pages may wind up * getting freed causing a previous write (bdwrite()) to get 'lost' * because pages associated with a B_DELWRI bp are marked clean. * * We still allow the B_INVAL case to call vfs_vmio_release(), even * if B_DELWRI is set. * * If B_DELWRI is not set we may have to set B_RELBUF if we are low * on pages to return pages to the VM page queues. */ if (bp->b_flags & B_DELWRI) bp->b_flags &= ~B_RELBUF; else if (buf_vm_page_count_severe()) { /* * The locking of the BO_LOCK is not necessary since * BKGRDINPROG cannot be set while we hold the buf * lock, it can only be cleared if it is already * pending. */ if (bp->b_vp) { if (!(bp->b_vflags & BV_BKGRDINPROG)) bp->b_flags |= B_RELBUF; } else bp->b_flags |= B_RELBUF; } /* * VMIO buffer rundown. It is not very necessary to keep a VMIO buffer * constituted, not even NFS buffers now. Two flags effect this. If * B_INVAL, the struct buf is invalidated but the VM object is kept * around ( i.e. so it is trivial to reconstitute the buffer later ). * * If BIO_ERROR or B_NOCACHE is set, pages in the VM object will be * invalidated. BIO_ERROR cannot be set for a failed write unless the * buffer is also B_INVAL because it hits the re-dirtying code above. * * Normally we can do this whether a buffer is B_DELWRI or not. If * the buffer is an NFS buffer, it is tracking piecemeal writes or * the commit state and we cannot afford to lose the buffer. If the * buffer has a background write in progress, we need to keep it * around to prevent it from being reconstituted and starting a second * background write. */ if ((bp->b_flags & B_VMIO) && !(bp->b_vp->v_mount != NULL && (bp->b_vp->v_mount->mnt_vfc->vfc_flags & VFCF_NETWORK) != 0 && !vn_isdisk(bp->b_vp, NULL) && (bp->b_flags & B_DELWRI)) ) { int i, j, resid; vm_page_t m; off_t foff; vm_pindex_t poff; vm_object_t obj; obj = bp->b_bufobj->bo_object; /* * Get the base offset and length of the buffer. Note that * in the VMIO case if the buffer block size is not * page-aligned then b_data pointer may not be page-aligned. * But our b_pages[] array *IS* page aligned. * * block sizes less then DEV_BSIZE (usually 512) are not * supported due to the page granularity bits (m->valid, * m->dirty, etc...). * * See man buf(9) for more information */ resid = bp->b_bufsize; foff = bp->b_offset; VM_OBJECT_LOCK(obj); for (i = 0; i < bp->b_npages; i++) { int had_bogus = 0; m = bp->b_pages[i]; /* * If we hit a bogus page, fixup *all* the bogus pages * now. */ if (m == bogus_page) { poff = OFF_TO_IDX(bp->b_offset); had_bogus = 1; for (j = i; j < bp->b_npages; j++) { vm_page_t mtmp; mtmp = bp->b_pages[j]; if (mtmp == bogus_page) { mtmp = vm_page_lookup(obj, poff + j); if (!mtmp) { panic("brelse: page missing\n"); } bp->b_pages[j] = mtmp; } } if ((bp->b_flags & B_INVAL) == 0) { pmap_qenter( trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages); } m = bp->b_pages[i]; } if ((bp->b_flags & B_NOCACHE) || (bp->b_ioflags & BIO_ERROR && bp->b_iocmd == BIO_READ)) { int poffset = foff & PAGE_MASK; int presid = resid > (PAGE_SIZE - poffset) ? (PAGE_SIZE - poffset) : resid; KASSERT(presid >= 0, ("brelse: extra page")); vm_page_set_invalid(m, poffset, presid); if (had_bogus) printf("avoided corruption bug in bogus_page/brelse code\n"); } resid -= PAGE_SIZE - (foff & PAGE_MASK); foff = (foff + PAGE_SIZE) & ~(off_t)PAGE_MASK; } VM_OBJECT_UNLOCK(obj); if (bp->b_flags & (B_INVAL | B_RELBUF)) vfs_vmio_release(bp); } else if (bp->b_flags & B_VMIO) { if (bp->b_flags & (B_INVAL | B_RELBUF)) { vfs_vmio_release(bp); } } else if ((bp->b_flags & (B_INVAL | B_RELBUF)) != 0) { if (bp->b_bufsize != 0) allocbuf(bp, 0); if (bp->b_vp != NULL) brelvp(bp); } /* enqueue */ mtx_lock(&bqlock); /* Handle delayed bremfree() processing. */ if (bp->b_flags & B_REMFREE) { struct bufobj *bo; bo = bp->b_bufobj; if (bo != NULL) BO_LOCK(bo); bremfreel(bp); if (bo != NULL) BO_UNLOCK(bo); } if (bp->b_qindex != QUEUE_NONE) panic("brelse: free buffer onto another queue???"); /* * If the buffer has junk contents signal it and eventually * clean up B_DELWRI and diassociate the vnode so that gbincore() * doesn't find it. */ if (bp->b_bufsize == 0 || (bp->b_ioflags & BIO_ERROR) != 0 || (bp->b_flags & (B_INVAL | B_NOCACHE | B_RELBUF)) != 0) bp->b_flags |= B_INVAL; if (bp->b_flags & B_INVAL) { if (bp->b_flags & B_DELWRI) bundirty(bp); if (bp->b_vp) brelvp(bp); } /* buffers with no memory */ if (bp->b_bufsize == 0) { bp->b_xflags &= ~(BX_BKGRDWRITE | BX_ALTDATA); if (bp->b_vflags & BV_BKGRDINPROG) panic("losing buffer 1"); if (bp->b_kvasize) { bp->b_qindex = QUEUE_EMPTYKVA; } else { bp->b_qindex = QUEUE_EMPTY; } TAILQ_INSERT_HEAD(&bufqueues[bp->b_qindex], bp, b_freelist); /* buffers with junk contents */ } else if (bp->b_flags & (B_INVAL | B_NOCACHE | B_RELBUF) || (bp->b_ioflags & BIO_ERROR)) { bp->b_xflags &= ~(BX_BKGRDWRITE | BX_ALTDATA); if (bp->b_vflags & BV_BKGRDINPROG) panic("losing buffer 2"); bp->b_qindex = QUEUE_CLEAN; TAILQ_INSERT_HEAD(&bufqueues[QUEUE_CLEAN], bp, b_freelist); /* remaining buffers */ } else { if ((bp->b_flags & (B_DELWRI|B_NEEDSGIANT)) == (B_DELWRI|B_NEEDSGIANT)) bp->b_qindex = QUEUE_DIRTY_GIANT; else if (bp->b_flags & B_DELWRI) bp->b_qindex = QUEUE_DIRTY; else bp->b_qindex = QUEUE_CLEAN; if (bp->b_flags & B_AGE) TAILQ_INSERT_HEAD(&bufqueues[bp->b_qindex], bp, b_freelist); else TAILQ_INSERT_TAIL(&bufqueues[bp->b_qindex], bp, b_freelist); } mtx_unlock(&bqlock); /* * Fixup numfreebuffers count. The bp is on an appropriate queue * unless locked. We then bump numfreebuffers if it is not B_DELWRI. * We've already handled the B_INVAL case ( B_DELWRI will be clear * if B_INVAL is set ). */ if (!(bp->b_flags & B_DELWRI)) { struct bufobj *bo; bo = bp->b_bufobj; if (bo != NULL) BO_LOCK(bo); bufcountwakeup(bp); if (bo != NULL) BO_UNLOCK(bo); } /* * Something we can maybe free or reuse */ if (bp->b_bufsize || bp->b_kvasize) bufspacewakeup(); bp->b_flags &= ~(B_ASYNC | B_NOCACHE | B_AGE | B_RELBUF | B_DIRECT); if ((bp->b_flags & B_DELWRI) == 0 && (bp->b_xflags & BX_VNDIRTY)) panic("brelse: not dirty"); /* unlock */ BUF_UNLOCK(bp); } /* * Release a buffer back to the appropriate queue but do not try to free * it. The buffer is expected to be used again soon. * * bqrelse() is used by bdwrite() to requeue a delayed write, and used by * biodone() to requeue an async I/O on completion. It is also used when * known good buffers need to be requeued but we think we may need the data * again soon. * * XXX we should be able to leave the B_RELBUF hint set on completion. */ void bqrelse(struct buf *bp) { struct bufobj *bo; CTR3(KTR_BUF, "bqrelse(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); KASSERT(!(bp->b_flags & (B_CLUSTER|B_PAGING)), ("bqrelse: inappropriate B_PAGING or B_CLUSTER bp %p", bp)); if (BUF_LOCKRECURSED(bp)) { /* do not release to free list */ BUF_UNLOCK(bp); return; } bo = bp->b_bufobj; if (bp->b_flags & B_MANAGED) { if (bp->b_flags & B_REMFREE) { mtx_lock(&bqlock); if (bo != NULL) BO_LOCK(bo); bremfreel(bp); if (bo != NULL) BO_UNLOCK(bo); mtx_unlock(&bqlock); } bp->b_flags &= ~(B_ASYNC | B_NOCACHE | B_AGE | B_RELBUF); BUF_UNLOCK(bp); return; } mtx_lock(&bqlock); /* Handle delayed bremfree() processing. */ if (bp->b_flags & B_REMFREE) { if (bo != NULL) BO_LOCK(bo); bremfreel(bp); if (bo != NULL) BO_UNLOCK(bo); } if (bp->b_qindex != QUEUE_NONE) panic("bqrelse: free buffer onto another queue???"); /* buffers with stale but valid contents */ if (bp->b_flags & B_DELWRI) { if (bp->b_flags & B_NEEDSGIANT) bp->b_qindex = QUEUE_DIRTY_GIANT; else bp->b_qindex = QUEUE_DIRTY; TAILQ_INSERT_TAIL(&bufqueues[bp->b_qindex], bp, b_freelist); } else { /* * The locking of the BO_LOCK for checking of the * BV_BKGRDINPROG is not necessary since the * BV_BKGRDINPROG cannot be set while we hold the buf * lock, it can only be cleared if it is already * pending. */ if (!buf_vm_page_count_severe() || (bp->b_vflags & BV_BKGRDINPROG)) { bp->b_qindex = QUEUE_CLEAN; TAILQ_INSERT_TAIL(&bufqueues[QUEUE_CLEAN], bp, b_freelist); } else { /* * We are too low on memory, we have to try to free * the buffer (most importantly: the wired pages * making up its backing store) *now*. */ mtx_unlock(&bqlock); brelse(bp); return; } } mtx_unlock(&bqlock); if ((bp->b_flags & B_INVAL) || !(bp->b_flags & B_DELWRI)) { if (bo != NULL) BO_LOCK(bo); bufcountwakeup(bp); if (bo != NULL) BO_UNLOCK(bo); } /* * Something we can maybe free or reuse. */ if (bp->b_bufsize && !(bp->b_flags & B_DELWRI)) bufspacewakeup(); bp->b_flags &= ~(B_ASYNC | B_NOCACHE | B_AGE | B_RELBUF); if ((bp->b_flags & B_DELWRI) == 0 && (bp->b_xflags & BX_VNDIRTY)) panic("bqrelse: not dirty"); /* unlock */ BUF_UNLOCK(bp); } /* Give pages used by the bp back to the VM system (where possible) */ static void vfs_vmio_release(struct buf *bp) { int i; vm_page_t m; pmap_qremove(trunc_page((vm_offset_t)bp->b_data), bp->b_npages); VM_OBJECT_LOCK(bp->b_bufobj->bo_object); for (i = 0; i < bp->b_npages; i++) { m = bp->b_pages[i]; bp->b_pages[i] = NULL; /* * In order to keep page LRU ordering consistent, put * everything on the inactive queue. */ vm_page_lock(m); vm_page_unwire(m, 0); /* * We don't mess with busy pages, it is * the responsibility of the process that * busied the pages to deal with them. */ if ((m->oflags & VPO_BUSY) == 0 && m->busy == 0 && m->wire_count == 0) { /* * Might as well free the page if we can and it has * no valid data. We also free the page if the * buffer was used for direct I/O */ if ((bp->b_flags & B_ASYNC) == 0 && !m->valid) { vm_page_free(m); } else if (bp->b_flags & B_DIRECT) { vm_page_try_to_free(m); } else if (buf_vm_page_count_severe()) { vm_page_try_to_cache(m); } } vm_page_unlock(m); } VM_OBJECT_UNLOCK(bp->b_bufobj->bo_object); if (bp->b_bufsize) { bufspacewakeup(); bp->b_bufsize = 0; } bp->b_npages = 0; bp->b_flags &= ~B_VMIO; if (bp->b_vp) brelvp(bp); } /* * Check to see if a block at a particular lbn is available for a clustered * write. */ static int vfs_bio_clcheck(struct vnode *vp, int size, daddr_t lblkno, daddr_t blkno) { struct buf *bpa; int match; match = 0; /* If the buf isn't in core skip it */ if ((bpa = gbincore(&vp->v_bufobj, lblkno)) == NULL) return (0); /* If the buf is busy we don't want to wait for it */ if (BUF_LOCK(bpa, LK_EXCLUSIVE | LK_NOWAIT, NULL) != 0) return (0); /* Only cluster with valid clusterable delayed write buffers */ if ((bpa->b_flags & (B_DELWRI | B_CLUSTEROK | B_INVAL)) != (B_DELWRI | B_CLUSTEROK)) goto done; if (bpa->b_bufsize != size) goto done; /* * Check to see if it is in the expected place on disk and that the * block has been mapped. */ if ((bpa->b_blkno != bpa->b_lblkno) && (bpa->b_blkno == blkno)) match = 1; done: BUF_UNLOCK(bpa); return (match); } /* * vfs_bio_awrite: * * Implement clustered async writes for clearing out B_DELWRI buffers. * This is much better then the old way of writing only one buffer at * a time. Note that we may not be presented with the buffers in the * correct order, so we search for the cluster in both directions. */ int vfs_bio_awrite(struct buf *bp) { struct bufobj *bo; int i; int j; daddr_t lblkno = bp->b_lblkno; struct vnode *vp = bp->b_vp; int ncl; int nwritten; int size; int maxcl; bo = &vp->v_bufobj; /* * right now we support clustered writing only to regular files. If * we find a clusterable block we could be in the middle of a cluster * rather then at the beginning. */ if ((vp->v_type == VREG) && (vp->v_mount != 0) && /* Only on nodes that have the size info */ (bp->b_flags & (B_CLUSTEROK | B_INVAL)) == B_CLUSTEROK) { size = vp->v_mount->mnt_stat.f_iosize; maxcl = MAXPHYS / size; BO_LOCK(bo); for (i = 1; i < maxcl; i++) if (vfs_bio_clcheck(vp, size, lblkno + i, bp->b_blkno + ((i * size) >> DEV_BSHIFT)) == 0) break; for (j = 1; i + j <= maxcl && j <= lblkno; j++) if (vfs_bio_clcheck(vp, size, lblkno - j, bp->b_blkno - ((j * size) >> DEV_BSHIFT)) == 0) break; BO_UNLOCK(bo); --j; ncl = i + j; /* * this is a possible cluster write */ if (ncl != 1) { BUF_UNLOCK(bp); nwritten = cluster_wbuild(vp, size, lblkno - j, ncl); return nwritten; } } bremfree(bp); bp->b_flags |= B_ASYNC; /* * default (old) behavior, writing out only one block * * XXX returns b_bufsize instead of b_bcount for nwritten? */ nwritten = bp->b_bufsize; (void) bwrite(bp); - return nwritten; + return (nwritten); } /* * getnewbuf: * * Find and initialize a new buffer header, freeing up existing buffers * in the bufqueues as necessary. The new buffer is returned locked. * * Important: B_INVAL is not set. If the caller wishes to throw the * buffer away, the caller must set B_INVAL prior to calling brelse(). * * We block if: * We have insufficient buffer headers * We have insufficient buffer space * buffer_map is too fragmented ( space reservation fails ) * If we have to flush dirty buffers ( but we try to avoid this ) * * To avoid VFS layer recursion we do not flush dirty buffers ourselves. * Instead we ask the buf daemon to do it for us. We attempt to * avoid piecemeal wakeups of the pageout daemon. */ static struct buf * getnewbuf(struct vnode *vp, int slpflag, int slptimeo, int size, int maxsize, int gbflags) { struct thread *td; struct buf *bp; struct buf *nbp; int defrag = 0; int nqindex; static int flushingbufs; td = curthread; /* * We can't afford to block since we might be holding a vnode lock, * which may prevent system daemons from running. We deal with * low-memory situations by proactively returning memory and running * async I/O rather then sync I/O. */ atomic_add_int(&getnewbufcalls, 1); atomic_subtract_int(&getnewbufrestarts, 1); restart: atomic_add_int(&getnewbufrestarts, 1); /* * Setup for scan. If we do not have enough free buffers, * we setup a degenerate case that immediately fails. Note * that if we are specially marked process, we are allowed to * dip into our reserves. * * The scanning sequence is nominally: EMPTY->EMPTYKVA->CLEAN * * We start with EMPTYKVA. If the list is empty we backup to EMPTY. * However, there are a number of cases (defragging, reusing, ...) * where we cannot backup. */ mtx_lock(&bqlock); nqindex = QUEUE_EMPTYKVA; nbp = TAILQ_FIRST(&bufqueues[QUEUE_EMPTYKVA]); if (nbp == NULL) { /* * If no EMPTYKVA buffers and we are either * defragging or reusing, locate a CLEAN buffer * to free or reuse. If bufspace useage is low * skip this step so we can allocate a new buffer. */ if (defrag || bufspace >= lobufspace) { nqindex = QUEUE_CLEAN; nbp = TAILQ_FIRST(&bufqueues[QUEUE_CLEAN]); } /* * If we could not find or were not allowed to reuse a * CLEAN buffer, check to see if it is ok to use an EMPTY * buffer. We can only use an EMPTY buffer if allocating * its KVA would not otherwise run us out of buffer space. */ if (nbp == NULL && defrag == 0 && bufspace + maxsize < hibufspace) { nqindex = QUEUE_EMPTY; nbp = TAILQ_FIRST(&bufqueues[QUEUE_EMPTY]); } } /* * Run scan, possibly freeing data and/or kva mappings on the fly * depending. */ while ((bp = nbp) != NULL) { int qindex = nqindex; /* * Calculate next bp ( we can only use it if we do not block * or do other fancy things ). */ if ((nbp = TAILQ_NEXT(bp, b_freelist)) == NULL) { switch(qindex) { case QUEUE_EMPTY: nqindex = QUEUE_EMPTYKVA; if ((nbp = TAILQ_FIRST(&bufqueues[QUEUE_EMPTYKVA]))) break; /* FALLTHROUGH */ case QUEUE_EMPTYKVA: nqindex = QUEUE_CLEAN; if ((nbp = TAILQ_FIRST(&bufqueues[QUEUE_CLEAN]))) break; /* FALLTHROUGH */ case QUEUE_CLEAN: /* * nbp is NULL. */ break; } } /* * If we are defragging then we need a buffer with * b_kvasize != 0. XXX this situation should no longer * occur, if defrag is non-zero the buffer's b_kvasize * should also be non-zero at this point. XXX */ if (defrag && bp->b_kvasize == 0) { printf("Warning: defrag empty buffer %p\n", bp); continue; } /* * Start freeing the bp. This is somewhat involved. nbp * remains valid only for QUEUE_EMPTY[KVA] bp's. */ if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL) != 0) continue; if (bp->b_vp) { BO_LOCK(bp->b_bufobj); if (bp->b_vflags & BV_BKGRDINPROG) { BO_UNLOCK(bp->b_bufobj); BUF_UNLOCK(bp); continue; } BO_UNLOCK(bp->b_bufobj); } CTR6(KTR_BUF, "getnewbuf(%p) vp %p flags %X kvasize %d bufsize %d " "queue %d (recycling)", bp, bp->b_vp, bp->b_flags, bp->b_kvasize, bp->b_bufsize, qindex); /* * Sanity Checks */ KASSERT(bp->b_qindex == qindex, ("getnewbuf: inconsistant queue %d bp %p", qindex, bp)); /* * Note: we no longer distinguish between VMIO and non-VMIO * buffers. */ KASSERT((bp->b_flags & B_DELWRI) == 0, ("delwri buffer %p found in queue %d", bp, qindex)); if (bp->b_bufobj != NULL) BO_LOCK(bp->b_bufobj); bremfreel(bp); if (bp->b_bufobj != NULL) BO_UNLOCK(bp->b_bufobj); mtx_unlock(&bqlock); if (qindex == QUEUE_CLEAN) { if (bp->b_flags & B_VMIO) { bp->b_flags &= ~B_ASYNC; vfs_vmio_release(bp); } if (bp->b_vp) brelvp(bp); } /* * NOTE: nbp is now entirely invalid. We can only restart * the scan from this point on. * * Get the rest of the buffer freed up. b_kva* is still * valid after this operation. */ if (bp->b_rcred != NOCRED) { crfree(bp->b_rcred); bp->b_rcred = NOCRED; } if (bp->b_wcred != NOCRED) { crfree(bp->b_wcred); bp->b_wcred = NOCRED; } if (!LIST_EMPTY(&bp->b_dep)) buf_deallocate(bp); if (bp->b_vflags & BV_BKGRDINPROG) panic("losing buffer 3"); KASSERT(bp->b_vp == NULL, ("bp: %p still has vnode %p. qindex: %d", bp, bp->b_vp, qindex)); KASSERT((bp->b_xflags & (BX_VNCLEAN|BX_VNDIRTY)) == 0, ("bp: %p still on a buffer list. xflags %X", bp, bp->b_xflags)); if (bp->b_bufsize) allocbuf(bp, 0); bp->b_flags = 0; bp->b_ioflags = 0; bp->b_xflags = 0; KASSERT((bp->b_vflags & BV_INFREECNT) == 0, ("buf %p still counted as free?", bp)); bp->b_vflags = 0; bp->b_vp = NULL; bp->b_blkno = bp->b_lblkno = 0; bp->b_offset = NOOFFSET; bp->b_iodone = 0; bp->b_error = 0; bp->b_resid = 0; bp->b_bcount = 0; bp->b_npages = 0; bp->b_dirtyoff = bp->b_dirtyend = 0; bp->b_bufobj = NULL; bp->b_pin_count = 0; bp->b_fsprivate1 = NULL; bp->b_fsprivate2 = NULL; bp->b_fsprivate3 = NULL; LIST_INIT(&bp->b_dep); /* * If we are defragging then free the buffer. */ if (defrag) { bp->b_flags |= B_INVAL; bfreekva(bp); brelse(bp); defrag = 0; goto restart; } /* * Notify any waiters for the buffer lock about * identity change by freeing the buffer. */ if (qindex == QUEUE_CLEAN && BUF_LOCKWAITERS(bp)) { bp->b_flags |= B_INVAL; bfreekva(bp); brelse(bp); goto restart; } /* * If we are overcomitted then recover the buffer and its * KVM space. This occurs in rare situations when multiple * processes are blocked in getnewbuf() or allocbuf(). */ if (bufspace >= hibufspace) flushingbufs = 1; if (flushingbufs && bp->b_kvasize != 0) { bp->b_flags |= B_INVAL; bfreekva(bp); brelse(bp); goto restart; } if (bufspace < lobufspace) flushingbufs = 0; break; } /* * If we exhausted our list, sleep as appropriate. We may have to * wakeup various daemons and write out some dirty buffers. * * Generally we are sleeping due to insufficient buffer space. */ if (bp == NULL) { int flags, norunbuf; char *waitmsg; int fl; if (defrag) { flags = VFS_BIO_NEED_BUFSPACE; waitmsg = "nbufkv"; } else if (bufspace >= hibufspace) { waitmsg = "nbufbs"; flags = VFS_BIO_NEED_BUFSPACE; } else { waitmsg = "newbuf"; flags = VFS_BIO_NEED_ANY; } mtx_lock(&nblock); needsbuffer |= flags; mtx_unlock(&nblock); mtx_unlock(&bqlock); bd_speedup(); /* heeeelp */ if (gbflags & GB_NOWAIT_BD) return (NULL); mtx_lock(&nblock); while (needsbuffer & flags) { if (vp != NULL && (td->td_pflags & TDP_BUFNEED) == 0) { mtx_unlock(&nblock); /* * getblk() is called with a vnode * locked, and some majority of the * dirty buffers may as well belong to * the vnode. Flushing the buffers * there would make a progress that * cannot be achieved by the * buf_daemon, that cannot lock the * vnode. */ norunbuf = ~(TDP_BUFNEED | TDP_NORUNNINGBUF) | (td->td_pflags & TDP_NORUNNINGBUF); /* play bufdaemon */ td->td_pflags |= TDP_BUFNEED | TDP_NORUNNINGBUF; fl = buf_do_flush(vp); td->td_pflags &= norunbuf; mtx_lock(&nblock); if (fl != 0) continue; if ((needsbuffer & flags) == 0) break; } if (msleep(&needsbuffer, &nblock, (PRIBIO + 4) | slpflag, waitmsg, slptimeo)) { mtx_unlock(&nblock); return (NULL); } } mtx_unlock(&nblock); } else { /* * We finally have a valid bp. We aren't quite out of the * woods, we still have to reserve kva space. In order * to keep fragmentation sane we only allocate kva in * BKVASIZE chunks. */ maxsize = (maxsize + BKVAMASK) & ~BKVAMASK; if (maxsize != bp->b_kvasize) { vm_offset_t addr = 0; int rv; bfreekva(bp); vm_map_lock(buffer_map); if (vm_map_findspace(buffer_map, vm_map_min(buffer_map), maxsize, &addr)) { /* * Buffer map is too fragmented. * We must defragment the map. */ atomic_add_int(&bufdefragcnt, 1); vm_map_unlock(buffer_map); defrag = 1; bp->b_flags |= B_INVAL; brelse(bp); goto restart; } rv = vm_map_insert(buffer_map, NULL, 0, addr, addr + maxsize, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT); KASSERT(rv == KERN_SUCCESS, ("vm_map_insert(buffer_map) rv %d", rv)); vm_map_unlock(buffer_map); bp->b_kvabase = (caddr_t)addr; bp->b_kvasize = maxsize; atomic_add_long(&bufspace, bp->b_kvasize); atomic_add_int(&bufreusecnt, 1); } bp->b_saveaddr = bp->b_kvabase; bp->b_data = bp->b_saveaddr; } return (bp); } /* * buf_daemon: * * buffer flushing daemon. Buffers are normally flushed by the * update daemon but if it cannot keep up this process starts to * take the load in an attempt to prevent getnewbuf() from blocking. */ static struct kproc_desc buf_kp = { "bufdaemon", buf_daemon, &bufdaemonproc }; SYSINIT(bufdaemon, SI_SUB_KTHREAD_BUF, SI_ORDER_FIRST, kproc_start, &buf_kp); static int buf_do_flush(struct vnode *vp) { int flushed; flushed = flushbufqueues(vp, QUEUE_DIRTY, 0); /* The list empty check here is slightly racy */ if (!TAILQ_EMPTY(&bufqueues[QUEUE_DIRTY_GIANT])) { mtx_lock(&Giant); flushed += flushbufqueues(vp, QUEUE_DIRTY_GIANT, 0); mtx_unlock(&Giant); } if (flushed == 0) { /* * Could not find any buffers without rollback * dependencies, so just write the first one * in the hopes of eventually making progress. */ flushbufqueues(vp, QUEUE_DIRTY, 1); if (!TAILQ_EMPTY( &bufqueues[QUEUE_DIRTY_GIANT])) { mtx_lock(&Giant); flushbufqueues(vp, QUEUE_DIRTY_GIANT, 1); mtx_unlock(&Giant); } } return (flushed); } static void buf_daemon() { int lodirtysave; /* * This process needs to be suspended prior to shutdown sync. */ EVENTHANDLER_REGISTER(shutdown_pre_sync, kproc_shutdown, bufdaemonproc, SHUTDOWN_PRI_LAST); /* * This process is allowed to take the buffer cache to the limit */ curthread->td_pflags |= TDP_NORUNNINGBUF | TDP_BUFNEED; mtx_lock(&bdlock); for (;;) { bd_request = 0; mtx_unlock(&bdlock); kproc_suspend_check(bufdaemonproc); lodirtysave = lodirtybuffers; if (bd_speedupreq) { lodirtybuffers = numdirtybuffers / 2; bd_speedupreq = 0; } /* * Do the flush. Limit the amount of in-transit I/O we * allow to build up, otherwise we would completely saturate * the I/O system. Wakeup any waiting processes before we * normally would so they can run in parallel with our drain. */ while (numdirtybuffers > lodirtybuffers) { if (buf_do_flush(NULL) == 0) break; kern_yield(PRI_UNCHANGED); } lodirtybuffers = lodirtysave; /* * Only clear bd_request if we have reached our low water * mark. The buf_daemon normally waits 1 second and * then incrementally flushes any dirty buffers that have * built up, within reason. * * If we were unable to hit our low water mark and couldn't * find any flushable buffers, we sleep half a second. * Otherwise we loop immediately. */ mtx_lock(&bdlock); if (numdirtybuffers <= lodirtybuffers) { /* * We reached our low water mark, reset the * request and sleep until we are needed again. * The sleep is just so the suspend code works. */ bd_request = 0; msleep(&bd_request, &bdlock, PVM, "psleep", hz); } else { /* * We couldn't find any flushable dirty buffers but * still have too many dirty buffers, we * have to sleep and try again. (rare) */ msleep(&bd_request, &bdlock, PVM, "qsleep", hz / 10); } } } /* * flushbufqueues: * * Try to flush a buffer in the dirty queue. We must be careful to * free up B_INVAL buffers instead of write them, which NFS is * particularly sensitive to. */ static int flushwithdeps = 0; SYSCTL_INT(_vfs, OID_AUTO, flushwithdeps, CTLFLAG_RW, &flushwithdeps, 0, "Number of buffers flushed with dependecies that require rollbacks"); static int flushbufqueues(struct vnode *lvp, int queue, int flushdeps) { struct buf *sentinel; struct vnode *vp; struct mount *mp; struct buf *bp; int hasdeps; int flushed; int target; if (lvp == NULL) { target = numdirtybuffers - lodirtybuffers; if (flushdeps && target > 2) target /= 2; } else target = flushbufqtarget; flushed = 0; bp = NULL; sentinel = malloc(sizeof(struct buf), M_TEMP, M_WAITOK | M_ZERO); sentinel->b_qindex = QUEUE_SENTINEL; mtx_lock(&bqlock); TAILQ_INSERT_HEAD(&bufqueues[queue], sentinel, b_freelist); while (flushed != target) { bp = TAILQ_NEXT(sentinel, b_freelist); if (bp != NULL) { TAILQ_REMOVE(&bufqueues[queue], sentinel, b_freelist); TAILQ_INSERT_AFTER(&bufqueues[queue], bp, sentinel, b_freelist); } else break; /* * Skip sentinels inserted by other invocations of the * flushbufqueues(), taking care to not reorder them. */ if (bp->b_qindex == QUEUE_SENTINEL) continue; /* * Only flush the buffers that belong to the * vnode locked by the curthread. */ if (lvp != NULL && bp->b_vp != lvp) continue; if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL) != 0) continue; if (bp->b_pin_count > 0) { BUF_UNLOCK(bp); continue; } BO_LOCK(bp->b_bufobj); if ((bp->b_vflags & BV_BKGRDINPROG) != 0 || (bp->b_flags & B_DELWRI) == 0) { BO_UNLOCK(bp->b_bufobj); BUF_UNLOCK(bp); continue; } BO_UNLOCK(bp->b_bufobj); if (bp->b_flags & B_INVAL) { bremfreel(bp); mtx_unlock(&bqlock); brelse(bp); flushed++; numdirtywakeup((lodirtybuffers + hidirtybuffers) / 2); mtx_lock(&bqlock); continue; } if (!LIST_EMPTY(&bp->b_dep) && buf_countdeps(bp, 0)) { if (flushdeps == 0) { BUF_UNLOCK(bp); continue; } hasdeps = 1; } else hasdeps = 0; /* * We must hold the lock on a vnode before writing * one of its buffers. Otherwise we may confuse, or * in the case of a snapshot vnode, deadlock the * system. * * The lock order here is the reverse of the normal * of vnode followed by buf lock. This is ok because * the NOWAIT will prevent deadlock. */ vp = bp->b_vp; if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { BUF_UNLOCK(bp); continue; } if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_CANRECURSE) == 0) { mtx_unlock(&bqlock); CTR3(KTR_BUF, "flushbufqueue(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); if (curproc == bufdaemonproc) vfs_bio_awrite(bp); else { bremfree(bp); bwrite(bp); notbufdflashes++; } vn_finished_write(mp); VOP_UNLOCK(vp, 0); flushwithdeps += hasdeps; flushed++; /* * Sleeping on runningbufspace while holding * vnode lock leads to deadlock. */ if (curproc == bufdaemonproc) waitrunningbufspace(); numdirtywakeup((lodirtybuffers + hidirtybuffers) / 2); mtx_lock(&bqlock); continue; } vn_finished_write(mp); BUF_UNLOCK(bp); } TAILQ_REMOVE(&bufqueues[queue], sentinel, b_freelist); mtx_unlock(&bqlock); free(sentinel, M_TEMP); return (flushed); } /* * Check to see if a block is currently memory resident. */ struct buf * incore(struct bufobj *bo, daddr_t blkno) { struct buf *bp; BO_LOCK(bo); bp = gbincore(bo, blkno); BO_UNLOCK(bo); return (bp); } /* * Returns true if no I/O is needed to access the * associated VM object. This is like incore except * it also hunts around in the VM system for the data. */ static int inmem(struct vnode * vp, daddr_t blkno) { vm_object_t obj; vm_offset_t toff, tinc, size; vm_page_t m; vm_ooffset_t off; ASSERT_VOP_LOCKED(vp, "inmem"); if (incore(&vp->v_bufobj, blkno)) return 1; if (vp->v_mount == NULL) return 0; obj = vp->v_object; if (obj == NULL) return (0); size = PAGE_SIZE; if (size > vp->v_mount->mnt_stat.f_iosize) size = vp->v_mount->mnt_stat.f_iosize; off = (vm_ooffset_t)blkno * (vm_ooffset_t)vp->v_mount->mnt_stat.f_iosize; VM_OBJECT_LOCK(obj); for (toff = 0; toff < vp->v_mount->mnt_stat.f_iosize; toff += tinc) { m = vm_page_lookup(obj, OFF_TO_IDX(off + toff)); if (!m) goto notinmem; tinc = size; if (tinc > PAGE_SIZE - ((toff + off) & PAGE_MASK)) tinc = PAGE_SIZE - ((toff + off) & PAGE_MASK); if (vm_page_is_valid(m, (vm_offset_t) ((toff + off) & PAGE_MASK), tinc) == 0) goto notinmem; } VM_OBJECT_UNLOCK(obj); return 1; notinmem: VM_OBJECT_UNLOCK(obj); return (0); } /* * Set the dirty range for a buffer based on the status of the dirty * bits in the pages comprising the buffer. The range is limited * to the size of the buffer. * * Tell the VM system that the pages associated with this buffer * are clean. This is used for delayed writes where the data is * going to go to disk eventually without additional VM intevention. * * Note that while we only really need to clean through to b_bcount, we * just go ahead and clean through to b_bufsize. */ static void vfs_clean_pages_dirty_buf(struct buf *bp) { vm_ooffset_t foff, noff, eoff; vm_page_t m; int i; if ((bp->b_flags & B_VMIO) == 0 || bp->b_bufsize == 0) return; foff = bp->b_offset; KASSERT(bp->b_offset != NOOFFSET, ("vfs_clean_pages_dirty_buf: no buffer offset")); VM_OBJECT_LOCK(bp->b_bufobj->bo_object); vfs_drain_busy_pages(bp); vfs_setdirty_locked_object(bp); for (i = 0; i < bp->b_npages; i++) { noff = (foff + PAGE_SIZE) & ~(off_t)PAGE_MASK; eoff = noff; if (eoff > bp->b_offset + bp->b_bufsize) eoff = bp->b_offset + bp->b_bufsize; m = bp->b_pages[i]; vfs_page_set_validclean(bp, foff, m); /* vm_page_clear_dirty(m, foff & PAGE_MASK, eoff - foff); */ foff = noff; } VM_OBJECT_UNLOCK(bp->b_bufobj->bo_object); } static void vfs_setdirty_locked_object(struct buf *bp) { vm_object_t object; int i; object = bp->b_bufobj->bo_object; VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); /* * We qualify the scan for modified pages on whether the * object has been flushed yet. */ if ((object->flags & OBJ_MIGHTBEDIRTY) != 0) { vm_offset_t boffset; vm_offset_t eoffset; /* * test the pages to see if they have been modified directly * by users through the VM system. */ for (i = 0; i < bp->b_npages; i++) vm_page_test_dirty(bp->b_pages[i]); /* * Calculate the encompassing dirty range, boffset and eoffset, * (eoffset - boffset) bytes. */ for (i = 0; i < bp->b_npages; i++) { if (bp->b_pages[i]->dirty) break; } boffset = (i << PAGE_SHIFT) - (bp->b_offset & PAGE_MASK); for (i = bp->b_npages - 1; i >= 0; --i) { if (bp->b_pages[i]->dirty) { break; } } eoffset = ((i + 1) << PAGE_SHIFT) - (bp->b_offset & PAGE_MASK); /* * Fit it to the buffer. */ if (eoffset > bp->b_bcount) eoffset = bp->b_bcount; /* * If we have a good dirty range, merge with the existing * dirty range. */ if (boffset < eoffset) { if (bp->b_dirtyoff > boffset) bp->b_dirtyoff = boffset; if (bp->b_dirtyend < eoffset) bp->b_dirtyend = eoffset; } } } /* * getblk: * * Get a block given a specified block and offset into a file/device. * The buffers B_DONE bit will be cleared on return, making it almost * ready for an I/O initiation. B_INVAL may or may not be set on * return. The caller should clear B_INVAL prior to initiating a * READ. * * For a non-VMIO buffer, B_CACHE is set to the opposite of B_INVAL for * an existing buffer. * * For a VMIO buffer, B_CACHE is modified according to the backing VM. * If getblk()ing a previously 0-sized invalid buffer, B_CACHE is set * and then cleared based on the backing VM. If the previous buffer is * non-0-sized but invalid, B_CACHE will be cleared. * * If getblk() must create a new buffer, the new buffer is returned with * both B_INVAL and B_CACHE clear unless it is a VMIO buffer, in which * case it is returned with B_INVAL clear and B_CACHE set based on the * backing VM. * * getblk() also forces a bwrite() for any B_DELWRI buffer whos * B_CACHE bit is clear. * * What this means, basically, is that the caller should use B_CACHE to * determine whether the buffer is fully valid or not and should clear * B_INVAL prior to issuing a read. If the caller intends to validate * the buffer by loading its data area with something, the caller needs * to clear B_INVAL. If the caller does this without issuing an I/O, * the caller should set B_CACHE ( as an optimization ), else the caller * should issue the I/O and biodone() will set B_CACHE if the I/O was * a write attempt or if it was a successfull read. If the caller * intends to issue a READ, the caller must clear B_INVAL and BIO_ERROR * prior to issuing the READ. biodone() will *not* clear B_INVAL. */ struct buf * -getblk(struct vnode * vp, daddr_t blkno, int size, int slpflag, int slptimeo, +getblk(struct vnode *vp, daddr_t blkno, int size, int slpflag, int slptimeo, int flags) { struct buf *bp; struct bufobj *bo; int error; CTR3(KTR_BUF, "getblk(%p, %ld, %d)", vp, (long)blkno, size); ASSERT_VOP_LOCKED(vp, "getblk"); if (size > MAXBSIZE) panic("getblk: size(%d) > MAXBSIZE(%d)\n", size, MAXBSIZE); bo = &vp->v_bufobj; loop: /* * Block if we are low on buffers. Certain processes are allowed * to completely exhaust the buffer cache. * * If this check ever becomes a bottleneck it may be better to * move it into the else, when gbincore() fails. At the moment * it isn't a problem. */ if (numfreebuffers == 0) { if (TD_IS_IDLETHREAD(curthread)) return NULL; mtx_lock(&nblock); needsbuffer |= VFS_BIO_NEED_ANY; mtx_unlock(&nblock); } BO_LOCK(bo); bp = gbincore(bo, blkno); if (bp != NULL) { int lockflags; /* * Buffer is in-core. If the buffer is not busy, it must * be on a queue. */ lockflags = LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK; if (flags & GB_LOCK_NOWAIT) lockflags |= LK_NOWAIT; error = BUF_TIMELOCK(bp, lockflags, BO_MTX(bo), "getblk", slpflag, slptimeo); /* * If we slept and got the lock we have to restart in case * the buffer changed identities. */ if (error == ENOLCK) goto loop; /* We timed out or were interrupted. */ else if (error) return (NULL); /* If recursed, assume caller knows the rules. */ else if (BUF_LOCKRECURSED(bp)) goto end; /* * The buffer is locked. B_CACHE is cleared if the buffer is * invalid. Otherwise, for a non-VMIO buffer, B_CACHE is set * and for a VMIO buffer B_CACHE is adjusted according to the * backing VM cache. */ if (bp->b_flags & B_INVAL) bp->b_flags &= ~B_CACHE; else if ((bp->b_flags & (B_VMIO | B_INVAL)) == 0) bp->b_flags |= B_CACHE; BO_LOCK(bo); bremfree(bp); BO_UNLOCK(bo); /* - * check for size inconsistancies for non-VMIO case. + * check for size inconsistencies for non-VMIO case. */ - if (bp->b_bcount != size) { if ((bp->b_flags & B_VMIO) == 0 || (size > bp->b_kvasize)) { if (bp->b_flags & B_DELWRI) { /* * If buffer is pinned and caller does * not want sleep waiting for it to be * unpinned, bail out * */ if (bp->b_pin_count > 0) { if (flags & GB_LOCK_NOWAIT) { bqrelse(bp); return (NULL); } else { bunpin_wait(bp); } } bp->b_flags |= B_NOCACHE; bwrite(bp); } else { if (LIST_EMPTY(&bp->b_dep)) { bp->b_flags |= B_RELBUF; brelse(bp); } else { bp->b_flags |= B_NOCACHE; bwrite(bp); } } goto loop; } } /* * If the size is inconsistant in the VMIO case, we can resize * the buffer. This might lead to B_CACHE getting set or * cleared. If the size has not changed, B_CACHE remains * unchanged from its previous state. */ if (bp->b_bcount != size) allocbuf(bp, size); KASSERT(bp->b_offset != NOOFFSET, ("getblk: no buffer offset")); /* * A buffer with B_DELWRI set and B_CACHE clear must * be committed before we can return the buffer in * order to prevent the caller from issuing a read * ( due to B_CACHE not being set ) and overwriting * it. * * Most callers, including NFS and FFS, need this to * operate properly either because they assume they * can issue a read if B_CACHE is not set, or because * ( for example ) an uncached B_DELWRI might loop due * to softupdates re-dirtying the buffer. In the latter * case, B_CACHE is set after the first write completes, * preventing further loops. * NOTE! b*write() sets B_CACHE. If we cleared B_CACHE * above while extending the buffer, we cannot allow the * buffer to remain with B_CACHE set after the write * completes or it will represent a corrupt state. To * deal with this we set B_NOCACHE to scrap the buffer * after the write. * * We might be able to do something fancy, like setting * B_CACHE in bwrite() except if B_DELWRI is already set, * so the below call doesn't set B_CACHE, but that gets real * confusing. This is much easier. */ if ((bp->b_flags & (B_CACHE|B_DELWRI)) == B_DELWRI) { bp->b_flags |= B_NOCACHE; bwrite(bp); goto loop; } bp->b_flags &= ~B_DONE; } else { int bsize, maxsize, vmio; off_t offset; /* * Buffer is not in-core, create new buffer. The buffer * returned by getnewbuf() is locked. Note that the returned * buffer is also considered valid (not marked B_INVAL). */ BO_UNLOCK(bo); /* * If the user does not want us to create the buffer, bail out * here. */ if (flags & GB_NOCREAT) return NULL; bsize = vn_isdisk(vp, NULL) ? DEV_BSIZE : bo->bo_bsize; offset = blkno * bsize; vmio = vp->v_object != NULL; maxsize = vmio ? size + (offset & PAGE_MASK) : size; maxsize = imax(maxsize, bsize); bp = getnewbuf(vp, slpflag, slptimeo, size, maxsize, flags); if (bp == NULL) { if (slpflag || slptimeo) return NULL; goto loop; } /* * This code is used to make sure that a buffer is not * created while the getnewbuf routine is blocked. * This can be a problem whether the vnode is locked or not. * If the buffer is created out from under us, we have to * throw away the one we just created. * * Note: this must occur before we associate the buffer * with the vp especially considering limitations in * the splay tree implementation when dealing with duplicate * lblkno's. */ BO_LOCK(bo); if (gbincore(bo, blkno)) { BO_UNLOCK(bo); bp->b_flags |= B_INVAL; brelse(bp); goto loop; } /* * Insert the buffer into the hash, so that it can * be found by incore. */ bp->b_blkno = bp->b_lblkno = blkno; bp->b_offset = offset; bgetvp(vp, bp); BO_UNLOCK(bo); /* * set B_VMIO bit. allocbuf() the buffer bigger. Since the * buffer size starts out as 0, B_CACHE will be set by * allocbuf() for the VMIO case prior to it testing the * backing store for validity. */ if (vmio) { bp->b_flags |= B_VMIO; KASSERT(vp->v_object == bp->b_bufobj->bo_object, ("ARGH! different b_bufobj->bo_object %p %p %p\n", bp, vp->v_object, bp->b_bufobj->bo_object)); } else { bp->b_flags &= ~B_VMIO; KASSERT(bp->b_bufobj->bo_object == NULL, ("ARGH! has b_bufobj->bo_object %p %p\n", bp, bp->b_bufobj->bo_object)); } allocbuf(bp, size); bp->b_flags &= ~B_DONE; } CTR4(KTR_BUF, "getblk(%p, %ld, %d) = %p", vp, (long)blkno, size, bp); BUF_ASSERT_HELD(bp); end: KASSERT(bp->b_bufobj == bo, ("bp %p wrong b_bufobj %p should be %p", bp, bp->b_bufobj, bo)); return (bp); } /* * Get an empty, disassociated buffer of given size. The buffer is initially * set to B_INVAL. */ struct buf * geteblk(int size, int flags) { struct buf *bp; int maxsize; maxsize = (size + BKVAMASK) & ~BKVAMASK; while ((bp = getnewbuf(NULL, 0, 0, size, maxsize, flags)) == NULL) { if ((flags & GB_NOWAIT_BD) && (curthread->td_pflags & TDP_BUFNEED) != 0) return (NULL); } allocbuf(bp, size); bp->b_flags |= B_INVAL; /* b_dep cleared by getnewbuf() */ BUF_ASSERT_HELD(bp); return (bp); } /* * This code constitutes the buffer memory from either anonymous system * memory (in the case of non-VMIO operations) or from an associated * VM object (in the case of VMIO operations). This code is able to * resize a buffer up or down. * * Note that this code is tricky, and has many complications to resolve * deadlock or inconsistant data situations. Tread lightly!!! * There are B_CACHE and B_DELWRI interactions that must be dealt with by * the caller. Calling this code willy nilly can result in the loss of data. * * allocbuf() only adjusts B_CACHE for VMIO buffers. getblk() deals with * B_CACHE for the non-VMIO case. */ int allocbuf(struct buf *bp, int size) { int newbsize, mbsize; int i; BUF_ASSERT_HELD(bp); if (bp->b_kvasize < size) panic("allocbuf: buffer too small"); if ((bp->b_flags & B_VMIO) == 0) { caddr_t origbuf; int origbufsize; /* * Just get anonymous memory from the kernel. Don't * mess with B_CACHE. */ mbsize = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); if (bp->b_flags & B_MALLOC) newbsize = mbsize; else newbsize = round_page(size); if (newbsize < bp->b_bufsize) { /* * malloced buffers are not shrunk */ if (bp->b_flags & B_MALLOC) { if (newbsize) { bp->b_bcount = size; } else { free(bp->b_data, M_BIOBUF); if (bp->b_bufsize) { atomic_subtract_long( &bufmallocspace, bp->b_bufsize); bufspacewakeup(); bp->b_bufsize = 0; } bp->b_saveaddr = bp->b_kvabase; bp->b_data = bp->b_saveaddr; bp->b_bcount = 0; bp->b_flags &= ~B_MALLOC; } return 1; } vm_hold_free_pages(bp, newbsize); } else if (newbsize > bp->b_bufsize) { /* * We only use malloced memory on the first allocation. * and revert to page-allocated memory when the buffer * grows. */ /* * There is a potential smp race here that could lead * to bufmallocspace slightly passing the max. It * is probably extremely rare and not worth worrying * over. */ if ( (bufmallocspace < maxbufmallocspace) && (bp->b_bufsize == 0) && (mbsize <= PAGE_SIZE/2)) { bp->b_data = malloc(mbsize, M_BIOBUF, M_WAITOK); bp->b_bufsize = mbsize; bp->b_bcount = size; bp->b_flags |= B_MALLOC; atomic_add_long(&bufmallocspace, mbsize); return 1; } origbuf = NULL; origbufsize = 0; /* * If the buffer is growing on its other-than-first allocation, * then we revert to the page-allocation scheme. */ if (bp->b_flags & B_MALLOC) { origbuf = bp->b_data; origbufsize = bp->b_bufsize; bp->b_data = bp->b_kvabase; if (bp->b_bufsize) { atomic_subtract_long(&bufmallocspace, bp->b_bufsize); bufspacewakeup(); bp->b_bufsize = 0; } bp->b_flags &= ~B_MALLOC; newbsize = round_page(newbsize); } vm_hold_load_pages( bp, (vm_offset_t) bp->b_data + bp->b_bufsize, (vm_offset_t) bp->b_data + newbsize); if (origbuf) { bcopy(origbuf, bp->b_data, origbufsize); free(origbuf, M_BIOBUF); } } } else { int desiredpages; newbsize = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); desiredpages = (size == 0) ? 0 : num_pages((bp->b_offset & PAGE_MASK) + newbsize); if (bp->b_flags & B_MALLOC) panic("allocbuf: VMIO buffer can't be malloced"); /* * Set B_CACHE initially if buffer is 0 length or will become * 0-length. */ if (size == 0 || bp->b_bufsize == 0) bp->b_flags |= B_CACHE; if (newbsize < bp->b_bufsize) { /* * DEV_BSIZE aligned new buffer size is less then the * DEV_BSIZE aligned existing buffer size. Figure out * if we have to remove any pages. */ if (desiredpages < bp->b_npages) { vm_page_t m; pmap_qremove((vm_offset_t)trunc_page( (vm_offset_t)bp->b_data) + (desiredpages << PAGE_SHIFT), (bp->b_npages - desiredpages)); VM_OBJECT_LOCK(bp->b_bufobj->bo_object); for (i = desiredpages; i < bp->b_npages; i++) { /* * the page is not freed here -- it * is the responsibility of * vnode_pager_setsize */ m = bp->b_pages[i]; KASSERT(m != bogus_page, ("allocbuf: bogus page found")); while (vm_page_sleep_if_busy(m, TRUE, "biodep")) continue; bp->b_pages[i] = NULL; vm_page_lock(m); vm_page_unwire(m, 0); vm_page_unlock(m); } VM_OBJECT_UNLOCK(bp->b_bufobj->bo_object); bp->b_npages = desiredpages; } } else if (size > bp->b_bcount) { /* * We are growing the buffer, possibly in a * byte-granular fashion. */ vm_object_t obj; vm_offset_t toff; vm_offset_t tinc; /* * Step 1, bring in the VM pages from the object, * allocating them if necessary. We must clear * B_CACHE if these pages are not valid for the * range covered by the buffer. */ obj = bp->b_bufobj->bo_object; VM_OBJECT_LOCK(obj); while (bp->b_npages < desiredpages) { vm_page_t m; /* * We must allocate system pages since blocking * here could interfere with paging I/O, no * matter which process we are. * * We can only test VPO_BUSY here. Blocking on * m->busy might lead to a deadlock: * vm_fault->getpages->cluster_read->allocbuf * Thus, we specify VM_ALLOC_IGN_SBUSY. */ m = vm_page_grab(obj, OFF_TO_IDX(bp->b_offset) + bp->b_npages, VM_ALLOC_NOBUSY | VM_ALLOC_SYSTEM | VM_ALLOC_WIRED | VM_ALLOC_RETRY | VM_ALLOC_IGN_SBUSY | VM_ALLOC_COUNT(desiredpages - bp->b_npages)); if (m->valid == 0) bp->b_flags &= ~B_CACHE; bp->b_pages[bp->b_npages] = m; ++bp->b_npages; } /* * Step 2. We've loaded the pages into the buffer, * we have to figure out if we can still have B_CACHE * set. Note that B_CACHE is set according to the * byte-granular range ( bcount and size ), new the * aligned range ( newbsize ). * * The VM test is against m->valid, which is DEV_BSIZE * aligned. Needless to say, the validity of the data * needs to also be DEV_BSIZE aligned. Note that this * fails with NFS if the server or some other client * extends the file's EOF. If our buffer is resized, * B_CACHE may remain set! XXX */ toff = bp->b_bcount; tinc = PAGE_SIZE - ((bp->b_offset + toff) & PAGE_MASK); while ((bp->b_flags & B_CACHE) && toff < size) { vm_pindex_t pi; if (tinc > (size - toff)) tinc = size - toff; pi = ((bp->b_offset & PAGE_MASK) + toff) >> PAGE_SHIFT; vfs_buf_test_cache( bp, bp->b_offset, toff, tinc, bp->b_pages[pi] ); toff += tinc; tinc = PAGE_SIZE; } VM_OBJECT_UNLOCK(obj); /* * Step 3, fixup the KVM pmap. Remember that * bp->b_data is relative to bp->b_offset, but * bp->b_offset may be offset into the first page. */ bp->b_data = (caddr_t) trunc_page((vm_offset_t)bp->b_data); pmap_qenter( (vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages ); bp->b_data = (caddr_t)((vm_offset_t)bp->b_data | (vm_offset_t)(bp->b_offset & PAGE_MASK)); } } if (newbsize < bp->b_bufsize) bufspacewakeup(); bp->b_bufsize = newbsize; /* actual buffer allocation */ bp->b_bcount = size; /* requested buffer size */ return 1; } void biodone(struct bio *bp) { struct mtx *mtxp; void (*done)(struct bio *); mtxp = mtx_pool_find(mtxpool_sleep, bp); mtx_lock(mtxp); bp->bio_flags |= BIO_DONE; done = bp->bio_done; if (done == NULL) wakeup(bp); mtx_unlock(mtxp); if (done != NULL) done(bp); } /* * Wait for a BIO to finish. * * XXX: resort to a timeout for now. The optimal locking (if any) for this * case is not yet clear. */ int biowait(struct bio *bp, const char *wchan) { struct mtx *mtxp; mtxp = mtx_pool_find(mtxpool_sleep, bp); mtx_lock(mtxp); while ((bp->bio_flags & BIO_DONE) == 0) msleep(bp, mtxp, PRIBIO, wchan, hz / 10); mtx_unlock(mtxp); if (bp->bio_error != 0) return (bp->bio_error); if (!(bp->bio_flags & BIO_ERROR)) return (0); return (EIO); } void biofinish(struct bio *bp, struct devstat *stat, int error) { if (error) { bp->bio_error = error; bp->bio_flags |= BIO_ERROR; } if (stat != NULL) devstat_end_transaction_bio(stat, bp); biodone(bp); } /* * bufwait: * * Wait for buffer I/O completion, returning error status. The buffer * is left locked and B_DONE on return. B_EINTR is converted into an EINTR * error and cleared. */ int bufwait(struct buf *bp) { if (bp->b_iocmd == BIO_READ) bwait(bp, PRIBIO, "biord"); else bwait(bp, PRIBIO, "biowr"); if (bp->b_flags & B_EINTR) { bp->b_flags &= ~B_EINTR; return (EINTR); } if (bp->b_ioflags & BIO_ERROR) { return (bp->b_error ? bp->b_error : EIO); } else { return (0); } } /* * Call back function from struct bio back up to struct buf. */ static void bufdonebio(struct bio *bip) { struct buf *bp; bp = bip->bio_caller2; bp->b_resid = bp->b_bcount - bip->bio_completed; bp->b_resid = bip->bio_resid; /* XXX: remove */ bp->b_ioflags = bip->bio_flags; bp->b_error = bip->bio_error; if (bp->b_error) bp->b_ioflags |= BIO_ERROR; bufdone(bp); g_destroy_bio(bip); } void dev_strategy(struct cdev *dev, struct buf *bp) { struct cdevsw *csw; int ref; KASSERT(dev->si_refcount > 0, ("dev_strategy on un-referenced struct cdev *(%s) %p", devtoname(dev), dev)); csw = dev_refthread(dev, &ref); dev_strategy_csw(dev, csw, bp); dev_relthread(dev, ref); } void dev_strategy_csw(struct cdev *dev, struct cdevsw *csw, struct buf *bp) { struct bio *bip; KASSERT(bp->b_iocmd == BIO_READ || bp->b_iocmd == BIO_WRITE, ("b_iocmd botch")); KASSERT(((dev->si_flags & SI_ETERNAL) != 0 && csw != NULL) || dev->si_threadcount > 0, ("dev_strategy_csw threadcount cdev *(%s) %p", devtoname(dev), dev)); if (csw == NULL) { bp->b_error = ENXIO; bp->b_ioflags = BIO_ERROR; bufdone(bp); return; } for (;;) { bip = g_new_bio(); if (bip != NULL) break; /* Try again later */ tsleep(&bp, PRIBIO, "dev_strat", hz/10); } bip->bio_cmd = bp->b_iocmd; bip->bio_offset = bp->b_iooffset; bip->bio_length = bp->b_bcount; bip->bio_bcount = bp->b_bcount; /* XXX: remove */ bip->bio_data = bp->b_data; bip->bio_done = bufdonebio; bip->bio_caller2 = bp; bip->bio_dev = dev; (*csw->d_strategy)(bip); } /* * bufdone: * * Finish I/O on a buffer, optionally calling a completion function. * This is usually called from an interrupt so process blocking is * not allowed. * * biodone is also responsible for setting B_CACHE in a B_VMIO bp. * In a non-VMIO bp, B_CACHE will be set on the next getblk() * assuming B_INVAL is clear. * * For the VMIO case, we set B_CACHE if the op was a read and no * read error occured, or if the op was a write. B_CACHE is never * set if the buffer is invalid or otherwise uncacheable. * * biodone does not mess with B_INVAL, allowing the I/O routine or the * initiator to leave B_INVAL set to brelse the buffer out of existance * in the biodone routine. */ void bufdone(struct buf *bp) { struct bufobj *dropobj; void (*biodone)(struct buf *); CTR3(KTR_BUF, "bufdone(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags); dropobj = NULL; KASSERT(!(bp->b_flags & B_DONE), ("biodone: bp %p already done", bp)); BUF_ASSERT_HELD(bp); runningbufwakeup(bp); if (bp->b_iocmd == BIO_WRITE) dropobj = bp->b_bufobj; /* call optional completion function if requested */ if (bp->b_iodone != NULL) { biodone = bp->b_iodone; bp->b_iodone = NULL; (*biodone) (bp); if (dropobj) bufobj_wdrop(dropobj); return; } bufdone_finish(bp); if (dropobj) bufobj_wdrop(dropobj); } void bufdone_finish(struct buf *bp) { BUF_ASSERT_HELD(bp); if (!LIST_EMPTY(&bp->b_dep)) buf_complete(bp); if (bp->b_flags & B_VMIO) { vm_ooffset_t foff; vm_page_t m; vm_object_t obj; struct vnode *vp; int bogus, i, iosize; obj = bp->b_bufobj->bo_object; KASSERT(obj->paging_in_progress >= bp->b_npages, ("biodone_finish: paging in progress(%d) < b_npages(%d)", obj->paging_in_progress, bp->b_npages)); vp = bp->b_vp; KASSERT(vp->v_holdcnt > 0, ("biodone_finish: vnode %p has zero hold count", vp)); KASSERT(vp->v_object != NULL, ("biodone_finish: vnode %p has no vm_object", vp)); foff = bp->b_offset; KASSERT(bp->b_offset != NOOFFSET, ("biodone_finish: bp %p has no buffer offset", bp)); /* * Set B_CACHE if the op was a normal read and no error * occured. B_CACHE is set for writes in the b*write() * routines. */ iosize = bp->b_bcount - bp->b_resid; if (bp->b_iocmd == BIO_READ && !(bp->b_flags & (B_INVAL|B_NOCACHE)) && !(bp->b_ioflags & BIO_ERROR)) { bp->b_flags |= B_CACHE; } bogus = 0; VM_OBJECT_LOCK(obj); for (i = 0; i < bp->b_npages; i++) { int bogusflag = 0; int resid; resid = ((foff + PAGE_SIZE) & ~(off_t)PAGE_MASK) - foff; if (resid > iosize) resid = iosize; /* * cleanup bogus pages, restoring the originals */ m = bp->b_pages[i]; if (m == bogus_page) { bogus = bogusflag = 1; m = vm_page_lookup(obj, OFF_TO_IDX(foff)); if (m == NULL) panic("biodone: page disappeared!"); bp->b_pages[i] = m; } KASSERT(OFF_TO_IDX(foff) == m->pindex, ("biodone_finish: foff(%jd)/pindex(%ju) mismatch", (intmax_t)foff, (uintmax_t)m->pindex)); /* * In the write case, the valid and clean bits are * already changed correctly ( see bdwrite() ), so we * only need to do this here in the read case. */ if ((bp->b_iocmd == BIO_READ) && !bogusflag && resid > 0) { KASSERT((m->dirty & vm_page_bits(foff & PAGE_MASK, resid)) == 0, ("bufdone_finish:" " page %p has unexpected dirty bits", m)); vfs_page_set_valid(bp, foff, m); } vm_page_io_finish(m); vm_object_pip_subtract(obj, 1); foff = (foff + PAGE_SIZE) & ~(off_t)PAGE_MASK; iosize -= resid; } vm_object_pip_wakeupn(obj, 0); VM_OBJECT_UNLOCK(obj); if (bogus) pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages); } /* * For asynchronous completions, release the buffer now. The brelse * will do a wakeup there if necessary - so no need to do a wakeup * here in the async case. The sync case always needs to do a wakeup. */ if (bp->b_flags & B_ASYNC) { if ((bp->b_flags & (B_NOCACHE | B_INVAL | B_RELBUF)) || (bp->b_ioflags & BIO_ERROR)) brelse(bp); else bqrelse(bp); } else bdone(bp); } /* * This routine is called in lieu of iodone in the case of * incomplete I/O. This keeps the busy status for pages * consistant. */ void vfs_unbusy_pages(struct buf *bp) { int i; vm_object_t obj; vm_page_t m; runningbufwakeup(bp); if (!(bp->b_flags & B_VMIO)) return; obj = bp->b_bufobj->bo_object; VM_OBJECT_LOCK(obj); for (i = 0; i < bp->b_npages; i++) { m = bp->b_pages[i]; if (m == bogus_page) { m = vm_page_lookup(obj, OFF_TO_IDX(bp->b_offset) + i); if (!m) panic("vfs_unbusy_pages: page missing\n"); bp->b_pages[i] = m; pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages); } vm_object_pip_subtract(obj, 1); vm_page_io_finish(m); } vm_object_pip_wakeupn(obj, 0); VM_OBJECT_UNLOCK(obj); } /* * vfs_page_set_valid: * * Set the valid bits in a page based on the supplied offset. The * range is restricted to the buffer's size. * * This routine is typically called after a read completes. */ static void vfs_page_set_valid(struct buf *bp, vm_ooffset_t off, vm_page_t m) { vm_ooffset_t eoff; /* * Compute the end offset, eoff, such that [off, eoff) does not span a * page boundary and eoff is not greater than the end of the buffer. * The end of the buffer, in this case, is our file EOF, not the * allocation size of the buffer. */ eoff = (off + PAGE_SIZE) & ~(vm_ooffset_t)PAGE_MASK; if (eoff > bp->b_offset + bp->b_bcount) eoff = bp->b_offset + bp->b_bcount; /* * Set valid range. This is typically the entire buffer and thus the * entire page. */ if (eoff > off) vm_page_set_valid(m, off & PAGE_MASK, eoff - off); } /* * vfs_page_set_validclean: * * Set the valid bits and clear the dirty bits in a page based on the * supplied offset. The range is restricted to the buffer's size. */ static void vfs_page_set_validclean(struct buf *bp, vm_ooffset_t off, vm_page_t m) { vm_ooffset_t soff, eoff; /* * Start and end offsets in buffer. eoff - soff may not cross a * page boundry or cross the end of the buffer. The end of the * buffer, in this case, is our file EOF, not the allocation size * of the buffer. */ soff = off; eoff = (off + PAGE_SIZE) & ~(off_t)PAGE_MASK; if (eoff > bp->b_offset + bp->b_bcount) eoff = bp->b_offset + bp->b_bcount; /* * Set valid range. This is typically the entire buffer and thus the * entire page. */ if (eoff > soff) { vm_page_set_validclean( m, (vm_offset_t) (soff & PAGE_MASK), (vm_offset_t) (eoff - soff) ); } } /* * Ensure that all buffer pages are not busied by VPO_BUSY flag. If * any page is busy, drain the flag. */ static void vfs_drain_busy_pages(struct buf *bp) { vm_page_t m; int i, last_busied; VM_OBJECT_LOCK_ASSERT(bp->b_bufobj->bo_object, MA_OWNED); last_busied = 0; for (i = 0; i < bp->b_npages; i++) { m = bp->b_pages[i]; if ((m->oflags & VPO_BUSY) != 0) { for (; last_busied < i; last_busied++) vm_page_busy(bp->b_pages[last_busied]); while ((m->oflags & VPO_BUSY) != 0) vm_page_sleep(m, "vbpage"); } } for (i = 0; i < last_busied; i++) vm_page_wakeup(bp->b_pages[i]); } /* * This routine is called before a device strategy routine. * It is used to tell the VM system that paging I/O is in * progress, and treat the pages associated with the buffer * almost as being VPO_BUSY. Also the object paging_in_progress * flag is handled to make sure that the object doesn't become * inconsistant. * * Since I/O has not been initiated yet, certain buffer flags * such as BIO_ERROR or B_INVAL may be in an inconsistant state * and should be ignored. */ void vfs_busy_pages(struct buf *bp, int clear_modify) { int i, bogus; vm_object_t obj; vm_ooffset_t foff; vm_page_t m; if (!(bp->b_flags & B_VMIO)) return; obj = bp->b_bufobj->bo_object; foff = bp->b_offset; KASSERT(bp->b_offset != NOOFFSET, ("vfs_busy_pages: no buffer offset")); VM_OBJECT_LOCK(obj); vfs_drain_busy_pages(bp); if (bp->b_bufsize != 0) vfs_setdirty_locked_object(bp); bogus = 0; for (i = 0; i < bp->b_npages; i++) { m = bp->b_pages[i]; if ((bp->b_flags & B_CLUSTER) == 0) { vm_object_pip_add(obj, 1); vm_page_io_start(m); } /* * When readying a buffer for a read ( i.e * clear_modify == 0 ), it is important to do * bogus_page replacement for valid pages in * partially instantiated buffers. Partially * instantiated buffers can, in turn, occur when * reconstituting a buffer from its VM backing store * base. We only have to do this if B_CACHE is * clear ( which causes the I/O to occur in the * first place ). The replacement prevents the read * I/O from overwriting potentially dirty VM-backed * pages. XXX bogus page replacement is, uh, bogus. * It may not work properly with small-block devices. * We need to find a better way. */ if (clear_modify) { pmap_remove_write(m); vfs_page_set_validclean(bp, foff, m); } else if (m->valid == VM_PAGE_BITS_ALL && (bp->b_flags & B_CACHE) == 0) { bp->b_pages[i] = bogus_page; bogus++; } foff = (foff + PAGE_SIZE) & ~(off_t)PAGE_MASK; } VM_OBJECT_UNLOCK(obj); if (bogus) pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages); } /* * vfs_bio_set_valid: * * Set the range within the buffer to valid. The range is * relative to the beginning of the buffer, b_offset. Note that * b_offset itself may be offset from the beginning of the first * page. */ void vfs_bio_set_valid(struct buf *bp, int base, int size) { int i, n; vm_page_t m; if (!(bp->b_flags & B_VMIO)) return; /* * Fixup base to be relative to beginning of first page. * Set initial n to be the maximum number of bytes in the * first page that can be validated. */ base += (bp->b_offset & PAGE_MASK); n = PAGE_SIZE - (base & PAGE_MASK); VM_OBJECT_LOCK(bp->b_bufobj->bo_object); for (i = base / PAGE_SIZE; size > 0 && i < bp->b_npages; ++i) { m = bp->b_pages[i]; if (n > size) n = size; vm_page_set_valid(m, base & PAGE_MASK, n); base += n; size -= n; n = PAGE_SIZE; } VM_OBJECT_UNLOCK(bp->b_bufobj->bo_object); } /* * vfs_bio_clrbuf: * * If the specified buffer is a non-VMIO buffer, clear the entire * buffer. If the specified buffer is a VMIO buffer, clear and * validate only the previously invalid portions of the buffer. * This routine essentially fakes an I/O, so we need to clear * BIO_ERROR and B_INVAL. * * Note that while we only theoretically need to clear through b_bcount, * we go ahead and clear through b_bufsize. */ void vfs_bio_clrbuf(struct buf *bp) { int i, j, mask, sa, ea, slide; if ((bp->b_flags & (B_VMIO | B_MALLOC)) != B_VMIO) { clrbuf(bp); return; } bp->b_flags &= ~B_INVAL; bp->b_ioflags &= ~BIO_ERROR; VM_OBJECT_LOCK(bp->b_bufobj->bo_object); if ((bp->b_npages == 1) && (bp->b_bufsize < PAGE_SIZE) && (bp->b_offset & PAGE_MASK) == 0) { if (bp->b_pages[0] == bogus_page) goto unlock; mask = (1 << (bp->b_bufsize / DEV_BSIZE)) - 1; VM_OBJECT_LOCK_ASSERT(bp->b_pages[0]->object, MA_OWNED); if ((bp->b_pages[0]->valid & mask) == mask) goto unlock; if ((bp->b_pages[0]->valid & mask) == 0) { pmap_zero_page_area(bp->b_pages[0], 0, bp->b_bufsize); bp->b_pages[0]->valid |= mask; goto unlock; } } sa = bp->b_offset & PAGE_MASK; slide = 0; for (i = 0; i < bp->b_npages; i++, sa = 0) { slide = imin(slide + PAGE_SIZE, bp->b_offset + bp->b_bufsize); ea = slide & PAGE_MASK; if (ea == 0) ea = PAGE_SIZE; if (bp->b_pages[i] == bogus_page) continue; j = sa / DEV_BSIZE; mask = ((1 << ((ea - sa) / DEV_BSIZE)) - 1) << j; VM_OBJECT_LOCK_ASSERT(bp->b_pages[i]->object, MA_OWNED); if ((bp->b_pages[i]->valid & mask) == mask) continue; if ((bp->b_pages[i]->valid & mask) == 0) pmap_zero_page_area(bp->b_pages[i], sa, ea - sa); else { for (; sa < ea; sa += DEV_BSIZE, j++) { if ((bp->b_pages[i]->valid & (1 << j)) == 0) { pmap_zero_page_area(bp->b_pages[i], sa, DEV_BSIZE); } } } bp->b_pages[i]->valid |= mask; } unlock: VM_OBJECT_UNLOCK(bp->b_bufobj->bo_object); bp->b_resid = 0; } /* * vm_hold_load_pages and vm_hold_free_pages get pages into * a buffers address space. The pages are anonymous and are * not associated with a file object. */ static void vm_hold_load_pages(struct buf *bp, vm_offset_t from, vm_offset_t to) { vm_offset_t pg; vm_page_t p; int index; to = round_page(to); from = round_page(from); index = (from - trunc_page((vm_offset_t)bp->b_data)) >> PAGE_SHIFT; for (pg = from; pg < to; pg += PAGE_SIZE, index++) { tryagain: /* * note: must allocate system pages since blocking here * could interfere with paging I/O, no matter which * process we are. */ p = vm_page_alloc(NULL, 0, VM_ALLOC_SYSTEM | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_COUNT((to - pg) >> PAGE_SHIFT)); if (p == NULL) { VM_WAIT; goto tryagain; } pmap_qenter(pg, &p, 1); bp->b_pages[index] = p; } bp->b_npages = index; } /* Return pages associated with this buf to the vm system */ static void vm_hold_free_pages(struct buf *bp, int newbsize) { vm_offset_t from; vm_page_t p; int index, newnpages; from = round_page((vm_offset_t)bp->b_data + newbsize); newnpages = (from - trunc_page((vm_offset_t)bp->b_data)) >> PAGE_SHIFT; if (bp->b_npages > newnpages) pmap_qremove(from, bp->b_npages - newnpages); for (index = newnpages; index < bp->b_npages; index++) { p = bp->b_pages[index]; bp->b_pages[index] = NULL; if (p->busy != 0) printf("vm_hold_free_pages: blkno: %jd, lblkno: %jd\n", (intmax_t)bp->b_blkno, (intmax_t)bp->b_lblkno); p->wire_count--; vm_page_free(p); atomic_subtract_int(&cnt.v_wire_count, 1); } bp->b_npages = newnpages; } /* * Map an IO request into kernel virtual address space. * * All requests are (re)mapped into kernel VA space. * Notice that we use b_bufsize for the size of the buffer * to be mapped. b_bcount might be modified by the driver. * * Note that even if the caller determines that the address space should * be valid, a race or a smaller-file mapped into a larger space may * actually cause vmapbuf() to fail, so all callers of vmapbuf() MUST * check the return value. */ int vmapbuf(struct buf *bp) { caddr_t kva; vm_prot_t prot; int pidx; if (bp->b_bufsize < 0) return (-1); prot = VM_PROT_READ; if (bp->b_iocmd == BIO_READ) prot |= VM_PROT_WRITE; /* Less backwards than it looks */ if ((pidx = vm_fault_quick_hold_pages(&curproc->p_vmspace->vm_map, (vm_offset_t)bp->b_data, bp->b_bufsize, prot, bp->b_pages, btoc(MAXPHYS))) < 0) return (-1); pmap_qenter((vm_offset_t)bp->b_saveaddr, bp->b_pages, pidx); kva = bp->b_saveaddr; bp->b_npages = pidx; bp->b_saveaddr = bp->b_data; bp->b_data = kva + (((vm_offset_t) bp->b_data) & PAGE_MASK); return(0); } /* * Free the io map PTEs associated with this IO operation. * We also invalidate the TLB entries and restore the original b_addr. */ void vunmapbuf(struct buf *bp) { int npages; npages = bp->b_npages; pmap_qremove(trunc_page((vm_offset_t)bp->b_data), npages); vm_page_unhold_pages(bp->b_pages, npages); bp->b_data = bp->b_saveaddr; } void bdone(struct buf *bp) { struct mtx *mtxp; mtxp = mtx_pool_find(mtxpool_sleep, bp); mtx_lock(mtxp); bp->b_flags |= B_DONE; wakeup(bp); mtx_unlock(mtxp); } void bwait(struct buf *bp, u_char pri, const char *wchan) { struct mtx *mtxp; mtxp = mtx_pool_find(mtxpool_sleep, bp); mtx_lock(mtxp); while ((bp->b_flags & B_DONE) == 0) msleep(bp, mtxp, pri, wchan, 0); mtx_unlock(mtxp); } int bufsync(struct bufobj *bo, int waitfor) { return (VOP_FSYNC(bo->__bo_vnode, waitfor, curthread)); } void bufstrategy(struct bufobj *bo, struct buf *bp) { int i = 0; struct vnode *vp; vp = bp->b_vp; KASSERT(vp == bo->bo_private, ("Inconsistent vnode bufstrategy")); KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, ("Wrong vnode in bufstrategy(bp=%p, vp=%p)", bp, vp)); i = VOP_STRATEGY(vp, bp); KASSERT(i == 0, ("VOP_STRATEGY failed bp=%p vp=%p", bp, bp->b_vp)); } void bufobj_wrefl(struct bufobj *bo) { KASSERT(bo != NULL, ("NULL bo in bufobj_wref")); ASSERT_BO_LOCKED(bo); bo->bo_numoutput++; } void bufobj_wref(struct bufobj *bo) { KASSERT(bo != NULL, ("NULL bo in bufobj_wref")); BO_LOCK(bo); bo->bo_numoutput++; BO_UNLOCK(bo); } void bufobj_wdrop(struct bufobj *bo) { KASSERT(bo != NULL, ("NULL bo in bufobj_wdrop")); BO_LOCK(bo); KASSERT(bo->bo_numoutput > 0, ("bufobj_wdrop non-positive count")); if ((--bo->bo_numoutput == 0) && (bo->bo_flag & BO_WWAIT)) { bo->bo_flag &= ~BO_WWAIT; wakeup(&bo->bo_numoutput); } BO_UNLOCK(bo); } int bufobj_wwait(struct bufobj *bo, int slpflag, int timeo) { int error; KASSERT(bo != NULL, ("NULL bo in bufobj_wwait")); ASSERT_BO_LOCKED(bo); error = 0; while (bo->bo_numoutput) { bo->bo_flag |= BO_WWAIT; error = msleep(&bo->bo_numoutput, BO_MTX(bo), slpflag | (PRIBIO + 1), "bo_wwait", timeo); if (error) break; } return (error); } void bpin(struct buf *bp) { struct mtx *mtxp; mtxp = mtx_pool_find(mtxpool_sleep, bp); mtx_lock(mtxp); bp->b_pin_count++; mtx_unlock(mtxp); } void bunpin(struct buf *bp) { struct mtx *mtxp; mtxp = mtx_pool_find(mtxpool_sleep, bp); mtx_lock(mtxp); if (--bp->b_pin_count == 0) wakeup(bp); mtx_unlock(mtxp); } void bunpin_wait(struct buf *bp) { struct mtx *mtxp; mtxp = mtx_pool_find(mtxpool_sleep, bp); mtx_lock(mtxp); while (bp->b_pin_count > 0) msleep(bp, mtxp, PRIBIO, "bwunpin", 0); mtx_unlock(mtxp); } #include "opt_ddb.h" #ifdef DDB #include /* DDB command to show buffer data */ DB_SHOW_COMMAND(buffer, db_show_buffer) { /* get args */ struct buf *bp = (struct buf *)addr; if (!have_addr) { db_printf("usage: show buffer \n"); return; } db_printf("buf at %p\n", bp); db_printf("b_flags = 0x%b, b_xflags=0x%b, b_vflags=0x%b\n", (u_int)bp->b_flags, PRINT_BUF_FLAGS, (u_int)bp->b_xflags, PRINT_BUF_XFLAGS, (u_int)bp->b_vflags, PRINT_BUF_VFLAGS); db_printf( "b_error = %d, b_bufsize = %ld, b_bcount = %ld, b_resid = %ld\n" "b_bufobj = (%p), b_data = %p, b_blkno = %jd, b_lblkno = %jd, " "b_dep = %p\n", bp->b_error, bp->b_bufsize, bp->b_bcount, bp->b_resid, bp->b_bufobj, bp->b_data, (intmax_t)bp->b_blkno, (intmax_t)bp->b_lblkno, bp->b_dep.lh_first); if (bp->b_npages) { int i; db_printf("b_npages = %d, pages(OBJ, IDX, PA): ", bp->b_npages); for (i = 0; i < bp->b_npages; i++) { vm_page_t m; m = bp->b_pages[i]; db_printf("(%p, 0x%lx, 0x%lx)", (void *)m->object, (u_long)m->pindex, (u_long)VM_PAGE_TO_PHYS(m)); if ((i + 1) < bp->b_npages) db_printf(","); } db_printf("\n"); } db_printf(" "); BUF_LOCKPRINTINFO(bp); } DB_SHOW_COMMAND(lockedbufs, lockedbufs) { struct buf *bp; int i; for (i = 0; i < nbuf; i++) { bp = &buf[i]; if (BUF_ISLOCKED(bp)) { db_show_buffer((uintptr_t)bp, 1, 0, NULL); db_printf("\n"); } } } DB_SHOW_COMMAND(vnodebufs, db_show_vnodebufs) { struct vnode *vp; struct buf *bp; if (!have_addr) { db_printf("usage: show vnodebufs \n"); return; } vp = (struct vnode *)addr; db_printf("Clean buffers:\n"); TAILQ_FOREACH(bp, &vp->v_bufobj.bo_clean.bv_hd, b_bobufs) { db_show_buffer((uintptr_t)bp, 1, 0, NULL); db_printf("\n"); } db_printf("Dirty buffers:\n"); TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, b_bobufs) { db_show_buffer((uintptr_t)bp, 1, 0, NULL); db_printf("\n"); } } DB_COMMAND(countfreebufs, db_coundfreebufs) { struct buf *bp; int i, used = 0, nfree = 0; if (have_addr) { db_printf("usage: countfreebufs\n"); return; } for (i = 0; i < nbuf; i++) { bp = &buf[i]; if ((bp->b_vflags & BV_INFREECNT) != 0) nfree++; else used++; } db_printf("Counted %d free, %d used (%d tot)\n", nfree, used, nfree + used); db_printf("numfreebuffers is %d\n", numfreebuffers); } #endif /* DDB */ Index: stable/9/sys/kern/vfs_cluster.c =================================================================== --- stable/9/sys/kern/vfs_cluster.c (revision 250946) +++ stable/9/sys/kern/vfs_cluster.c (revision 250947) @@ -1,1025 +1,1025 @@ /*- * Copyright (c) 1993 * The Regents of the University of California. All rights reserved. * Modifications/enhancements: * Copyright (c) 1995 John S. Dyson. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)vfs_cluster.c 8.7 (Berkeley) 2/13/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_debug_cluster.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(CLUSTERDEBUG) static int rcluster= 0; SYSCTL_INT(_debug, OID_AUTO, rcluster, CTLFLAG_RW, &rcluster, 0, "Debug VFS clustering code"); #endif static MALLOC_DEFINE(M_SEGMENT, "cl_savebuf", "cluster_save buffer"); static struct cluster_save * cluster_collectbufs(struct vnode *vp, struct buf *last_bp); static struct buf * cluster_rbuild(struct vnode *vp, u_quad_t filesize, daddr_t lbn, daddr_t blkno, long size, int run, struct buf *fbp); static void cluster_callback(struct buf *); static int write_behind = 1; SYSCTL_INT(_vfs, OID_AUTO, write_behind, CTLFLAG_RW, &write_behind, 0, "Cluster write-behind; 0: disable, 1: enable, 2: backed off"); static int read_max = 64; SYSCTL_INT(_vfs, OID_AUTO, read_max, CTLFLAG_RW, &read_max, 0, "Cluster read-ahead max block count"); static int read_min = 1; SYSCTL_INT(_vfs, OID_AUTO, read_min, CTLFLAG_RW, &read_min, 0, "Cluster read min block count"); /* Page expended to mark partially backed buffers */ extern vm_page_t bogus_page; /* * Read data to a buf, including read-ahead if we find this to be beneficial. * cluster_read replaces bread. */ int cluster_read(vp, filesize, lblkno, size, cred, totread, seqcount, bpp) struct vnode *vp; u_quad_t filesize; daddr_t lblkno; long size; struct ucred *cred; long totread; int seqcount; struct buf **bpp; { struct buf *bp, *rbp, *reqbp; struct bufobj *bo; daddr_t blkno, origblkno; int maxra, racluster; int error, ncontig; int i; error = 0; bo = &vp->v_bufobj; /* * Try to limit the amount of read-ahead by a few * ad-hoc parameters. This needs work!!! */ racluster = vp->v_mount->mnt_iosize_max / size; maxra = seqcount; maxra = min(read_max, maxra); maxra = min(nbuf/8, maxra); if (((u_quad_t)(lblkno + maxra + 1) * size) > filesize) maxra = (filesize / size) - lblkno; /* * get the requested block */ *bpp = reqbp = bp = getblk(vp, lblkno, size, 0, 0, 0); origblkno = lblkno; /* * if it is in the cache, then check to see if the reads have been * sequential. If they have, then try some read-ahead, otherwise * back-off on prospective read-aheads. */ if (bp->b_flags & B_CACHE) { if (!seqcount) { return 0; } else if ((bp->b_flags & B_RAM) == 0) { return 0; } else { bp->b_flags &= ~B_RAM; BO_LOCK(bo); for (i = 1; i < maxra; i++) { /* * Stop if the buffer does not exist or it * is invalid (about to go away?) */ rbp = gbincore(&vp->v_bufobj, lblkno+i); if (rbp == NULL || (rbp->b_flags & B_INVAL)) break; /* * Set another read-ahead mark so we know * to check again. (If we can lock the * buffer without waiting) */ if ((((i % racluster) == (racluster - 1)) || (i == (maxra - 1))) && (0 == BUF_LOCK(rbp, LK_EXCLUSIVE | LK_NOWAIT, NULL))) { rbp->b_flags |= B_RAM; BUF_UNLOCK(rbp); } } BO_UNLOCK(bo); if (i >= maxra) { return 0; } lblkno += i; } reqbp = bp = NULL; /* * If it isn't in the cache, then get a chunk from * disk if sequential, otherwise just get the block. */ } else { off_t firstread = bp->b_offset; int nblks; long minread; KASSERT(bp->b_offset != NOOFFSET, ("cluster_read: no buffer offset")); ncontig = 0; /* * Adjust totread if needed */ minread = read_min * size; if (minread > totread) totread = minread; /* * Compute the total number of blocks that we should read * synchronously. */ if (firstread + totread > filesize) totread = filesize - firstread; nblks = howmany(totread, size); if (nblks > racluster) nblks = racluster; /* * Now compute the number of contiguous blocks. */ if (nblks > 1) { error = VOP_BMAP(vp, lblkno, NULL, &blkno, &ncontig, NULL); /* * If this failed to map just do the original block. */ if (error || blkno == -1) ncontig = 0; } /* * If we have contiguous data available do a cluster * otherwise just read the requested block. */ if (ncontig) { /* Account for our first block. */ ncontig = min(ncontig + 1, nblks); if (ncontig < nblks) nblks = ncontig; bp = cluster_rbuild(vp, filesize, lblkno, blkno, size, nblks, bp); lblkno += (bp->b_bufsize / size); } else { bp->b_flags |= B_RAM; bp->b_iocmd = BIO_READ; lblkno += 1; } } /* * handle the synchronous read so that it is available ASAP. */ if (bp) { if ((bp->b_flags & B_CLUSTER) == 0) { vfs_busy_pages(bp, 0); } bp->b_flags &= ~B_INVAL; bp->b_ioflags &= ~BIO_ERROR; if ((bp->b_flags & B_ASYNC) || bp->b_iodone != NULL) BUF_KERNPROC(bp); bp->b_iooffset = dbtob(bp->b_blkno); bstrategy(bp); curthread->td_ru.ru_inblock++; } /* * If we have been doing sequential I/O, then do some read-ahead. */ while (lblkno < (origblkno + maxra)) { error = VOP_BMAP(vp, lblkno, NULL, &blkno, &ncontig, NULL); if (error) break; if (blkno == -1) break; /* * We could throttle ncontig here by maxra but we might as * well read the data if it is contiguous. We're throttled * by racluster anyway. */ if (ncontig) { ncontig = min(ncontig + 1, racluster); rbp = cluster_rbuild(vp, filesize, lblkno, blkno, size, ncontig, NULL); lblkno += (rbp->b_bufsize / size); if (rbp->b_flags & B_DELWRI) { bqrelse(rbp); continue; } } else { rbp = getblk(vp, lblkno, size, 0, 0, 0); lblkno += 1; if (rbp->b_flags & B_DELWRI) { bqrelse(rbp); continue; } rbp->b_flags |= B_ASYNC | B_RAM; rbp->b_iocmd = BIO_READ; rbp->b_blkno = blkno; } if (rbp->b_flags & B_CACHE) { rbp->b_flags &= ~B_ASYNC; bqrelse(rbp); continue; } if ((rbp->b_flags & B_CLUSTER) == 0) { vfs_busy_pages(rbp, 0); } rbp->b_flags &= ~B_INVAL; rbp->b_ioflags &= ~BIO_ERROR; if ((rbp->b_flags & B_ASYNC) || rbp->b_iodone != NULL) BUF_KERNPROC(rbp); rbp->b_iooffset = dbtob(rbp->b_blkno); bstrategy(rbp); curthread->td_ru.ru_inblock++; } if (reqbp) return (bufwait(reqbp)); else return (error); } /* * If blocks are contiguous on disk, use this to provide clustered * read ahead. We will read as many blocks as possible sequentially * and then parcel them up into logical blocks in the buffer hash table. */ static struct buf * cluster_rbuild(vp, filesize, lbn, blkno, size, run, fbp) struct vnode *vp; u_quad_t filesize; daddr_t lbn; daddr_t blkno; long size; int run; struct buf *fbp; { struct bufobj *bo; struct buf *bp, *tbp; daddr_t bn; off_t off; long tinc, tsize; int i, inc, j, toff; KASSERT(size == vp->v_mount->mnt_stat.f_iosize, ("cluster_rbuild: size %ld != filesize %jd\n", size, (intmax_t)vp->v_mount->mnt_stat.f_iosize)); /* * avoid a division */ while ((u_quad_t) size * (lbn + run) > filesize) { --run; } if (fbp) { tbp = fbp; tbp->b_iocmd = BIO_READ; } else { tbp = getblk(vp, lbn, size, 0, 0, 0); if (tbp->b_flags & B_CACHE) return tbp; tbp->b_flags |= B_ASYNC | B_RAM; tbp->b_iocmd = BIO_READ; } tbp->b_blkno = blkno; if( (tbp->b_flags & B_MALLOC) || ((tbp->b_flags & B_VMIO) == 0) || (run <= 1) ) return tbp; bp = trypbuf(&cluster_pbuf_freecnt); if (bp == 0) return tbp; /* * We are synthesizing a buffer out of vm_page_t's, but * if the block size is not page aligned then the starting * address may not be either. Inherit the b_data offset * from the original buffer. */ bp->b_data = (char *)((vm_offset_t)bp->b_data | ((vm_offset_t)tbp->b_data & PAGE_MASK)); bp->b_flags = B_ASYNC | B_CLUSTER | B_VMIO; bp->b_iocmd = BIO_READ; bp->b_iodone = cluster_callback; bp->b_blkno = blkno; bp->b_lblkno = lbn; bp->b_offset = tbp->b_offset; KASSERT(bp->b_offset != NOOFFSET, ("cluster_rbuild: no buffer offset")); pbgetvp(vp, bp); TAILQ_INIT(&bp->b_cluster.cluster_head); bp->b_bcount = 0; bp->b_bufsize = 0; bp->b_npages = 0; inc = btodb(size); bo = &vp->v_bufobj; for (bn = blkno, i = 0; i < run; ++i, bn += inc) { if (i != 0) { if ((bp->b_npages * PAGE_SIZE) + round_page(size) > vp->v_mount->mnt_iosize_max) { break; } tbp = getblk(vp, lbn + i, size, 0, 0, GB_LOCK_NOWAIT); /* Don't wait around for locked bufs. */ if (tbp == NULL) break; /* * Stop scanning if the buffer is fully valid * (marked B_CACHE), or locked (may be doing a * background write), or if the buffer is not * VMIO backed. The clustering code can only deal * with VMIO-backed buffers. */ BO_LOCK(bo); if ((tbp->b_vflags & BV_BKGRDINPROG) || (tbp->b_flags & B_CACHE) || (tbp->b_flags & B_VMIO) == 0) { BO_UNLOCK(bo); bqrelse(tbp); break; } BO_UNLOCK(bo); /* * The buffer must be completely invalid in order to * take part in the cluster. If it is partially valid * then we stop. */ off = tbp->b_offset; tsize = size; VM_OBJECT_LOCK(tbp->b_bufobj->bo_object); for (j = 0; tsize > 0; j++) { toff = off & PAGE_MASK; tinc = tsize; if (toff + tinc > PAGE_SIZE) tinc = PAGE_SIZE - toff; VM_OBJECT_LOCK_ASSERT(tbp->b_pages[j]->object, MA_OWNED); if ((tbp->b_pages[j]->valid & vm_page_bits(toff, tinc)) != 0) break; off += tinc; tsize -= tinc; } VM_OBJECT_UNLOCK(tbp->b_bufobj->bo_object); if (tsize > 0) { bqrelse(tbp); break; } /* * Set a read-ahead mark as appropriate */ if ((fbp && (i == 1)) || (i == (run - 1))) tbp->b_flags |= B_RAM; /* * Set the buffer up for an async read (XXX should * we do this only if we do not wind up brelse()ing?). * Set the block number if it isn't set, otherwise * if it is make sure it matches the block number we * expect. */ tbp->b_flags |= B_ASYNC; tbp->b_iocmd = BIO_READ; if (tbp->b_blkno == tbp->b_lblkno) { tbp->b_blkno = bn; } else if (tbp->b_blkno != bn) { brelse(tbp); break; } } /* * XXX fbp from caller may not be B_ASYNC, but we are going * to biodone() it in cluster_callback() anyway */ BUF_KERNPROC(tbp); TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head, tbp, b_cluster.cluster_entry); VM_OBJECT_LOCK(tbp->b_bufobj->bo_object); for (j = 0; j < tbp->b_npages; j += 1) { vm_page_t m; m = tbp->b_pages[j]; vm_page_io_start(m); vm_object_pip_add(m->object, 1); if ((bp->b_npages == 0) || (bp->b_pages[bp->b_npages-1] != m)) { bp->b_pages[bp->b_npages] = m; bp->b_npages++; } if (m->valid == VM_PAGE_BITS_ALL) tbp->b_pages[j] = bogus_page; } VM_OBJECT_UNLOCK(tbp->b_bufobj->bo_object); /* * Don't inherit tbp->b_bufsize as it may be larger due to * a non-page-aligned size. Instead just aggregate using * 'size'. */ if (tbp->b_bcount != size) printf("warning: tbp->b_bcount wrong %ld vs %ld\n", tbp->b_bcount, size); if (tbp->b_bufsize != size) printf("warning: tbp->b_bufsize wrong %ld vs %ld\n", tbp->b_bufsize, size); bp->b_bcount += size; bp->b_bufsize += size; } /* * Fully valid pages in the cluster are already good and do not need * to be re-read from disk. Replace the page with bogus_page */ VM_OBJECT_LOCK(bp->b_bufobj->bo_object); for (j = 0; j < bp->b_npages; j++) { VM_OBJECT_LOCK_ASSERT(bp->b_pages[j]->object, MA_OWNED); if (bp->b_pages[j]->valid == VM_PAGE_BITS_ALL) bp->b_pages[j] = bogus_page; } VM_OBJECT_UNLOCK(bp->b_bufobj->bo_object); if (bp->b_bufsize > bp->b_kvasize) panic("cluster_rbuild: b_bufsize(%ld) > b_kvasize(%d)\n", bp->b_bufsize, bp->b_kvasize); bp->b_kvasize = bp->b_bufsize; pmap_qenter(trunc_page((vm_offset_t) bp->b_data), (vm_page_t *)bp->b_pages, bp->b_npages); return (bp); } /* * Cleanup after a clustered read or write. * This is complicated by the fact that any of the buffers might have * extra memory (if there were no empty buffer headers at allocbuf time) * that we will need to shift around. */ static void cluster_callback(bp) struct buf *bp; { struct buf *nbp, *tbp; int error = 0; /* * Must propogate errors to all the components. */ if (bp->b_ioflags & BIO_ERROR) error = bp->b_error; pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_npages); /* * Move memory from the large cluster buffer into the component * buffers and mark IO as done on these. */ for (tbp = TAILQ_FIRST(&bp->b_cluster.cluster_head); tbp; tbp = nbp) { nbp = TAILQ_NEXT(&tbp->b_cluster, cluster_entry); if (error) { tbp->b_ioflags |= BIO_ERROR; tbp->b_error = error; } else { tbp->b_dirtyoff = tbp->b_dirtyend = 0; tbp->b_flags &= ~B_INVAL; tbp->b_ioflags &= ~BIO_ERROR; /* * XXX the bdwrite()/bqrelse() issued during * cluster building clears B_RELBUF (see bqrelse() * comment). If direct I/O was specified, we have * to restore it here to allow the buffer and VM * to be freed. */ if (tbp->b_flags & B_DIRECT) tbp->b_flags |= B_RELBUF; } bufdone(tbp); } pbrelvp(bp); relpbuf(bp, &cluster_pbuf_freecnt); } /* * cluster_wbuild_wb: * * Implement modified write build for cluster. * * write_behind = 0 write behind disabled * write_behind = 1 write behind normal (default) * write_behind = 2 write behind backed-off */ static __inline int cluster_wbuild_wb(struct vnode *vp, long size, daddr_t start_lbn, int len) { int r = 0; - switch(write_behind) { + switch (write_behind) { case 2: if (start_lbn < len) break; start_lbn -= len; /* FALLTHROUGH */ case 1: r = cluster_wbuild(vp, size, start_lbn, len); /* FALLTHROUGH */ default: /* FALLTHROUGH */ break; } return(r); } /* * Do clustered write for FFS. * * Three cases: * 1. Write is not sequential (write asynchronously) * Write is sequential: * 2. beginning of cluster - begin cluster * 3. middle of a cluster - add to cluster * 4. end of a cluster - asynchronously write cluster */ void cluster_write(struct vnode *vp, struct buf *bp, u_quad_t filesize, int seqcount) { daddr_t lbn; int maxclen, cursize; int lblocksize; int async; if (vp->v_type == VREG) { async = DOINGASYNC(vp); lblocksize = vp->v_mount->mnt_stat.f_iosize; } else { async = 0; lblocksize = bp->b_bufsize; } lbn = bp->b_lblkno; KASSERT(bp->b_offset != NOOFFSET, ("cluster_write: no buffer offset")); /* Initialize vnode to beginning of file. */ if (lbn == 0) vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0; if (vp->v_clen == 0 || lbn != vp->v_lastw + 1 || (bp->b_blkno != vp->v_lasta + btodb(lblocksize))) { maxclen = vp->v_mount->mnt_iosize_max / lblocksize - 1; if (vp->v_clen != 0) { /* * Next block is not sequential. * * If we are not writing at end of file, the process * seeked to another point in the file since its last * write, or we have reached our maximum cluster size, * then push the previous cluster. Otherwise try * reallocating to make it sequential. * * Change to algorithm: only push previous cluster if * it was sequential from the point of view of the * seqcount heuristic, otherwise leave the buffer * intact so we can potentially optimize the I/O * later on in the buf_daemon or update daemon * flush. */ cursize = vp->v_lastw - vp->v_cstart + 1; if (((u_quad_t) bp->b_offset + lblocksize) != filesize || lbn != vp->v_lastw + 1 || vp->v_clen <= cursize) { if (!async && seqcount > 0) { cluster_wbuild_wb(vp, lblocksize, vp->v_cstart, cursize); } } else { struct buf **bpp, **endbp; struct cluster_save *buflist; buflist = cluster_collectbufs(vp, bp); endbp = &buflist->bs_children [buflist->bs_nchildren - 1]; if (VOP_REALLOCBLKS(vp, buflist)) { /* * Failed, push the previous cluster * if *really* writing sequentially * in the logical file (seqcount > 1), * otherwise delay it in the hopes that * the low level disk driver can * optimize the write ordering. */ for (bpp = buflist->bs_children; bpp < endbp; bpp++) brelse(*bpp); free(buflist, M_SEGMENT); if (seqcount > 1) { cluster_wbuild_wb(vp, lblocksize, vp->v_cstart, cursize); } } else { /* * Succeeded, keep building cluster. */ for (bpp = buflist->bs_children; bpp <= endbp; bpp++) bdwrite(*bpp); free(buflist, M_SEGMENT); vp->v_lastw = lbn; vp->v_lasta = bp->b_blkno; return; } } } /* * Consider beginning a cluster. If at end of file, make * cluster as large as possible, otherwise find size of * existing cluster. */ if ((vp->v_type == VREG) && ((u_quad_t) bp->b_offset + lblocksize) != filesize && (bp->b_blkno == bp->b_lblkno) && (VOP_BMAP(vp, lbn, NULL, &bp->b_blkno, &maxclen, NULL) || bp->b_blkno == -1)) { bawrite(bp); vp->v_clen = 0; vp->v_lasta = bp->b_blkno; vp->v_cstart = lbn + 1; vp->v_lastw = lbn; return; } vp->v_clen = maxclen; if (!async && maxclen == 0) { /* I/O not contiguous */ vp->v_cstart = lbn + 1; bawrite(bp); } else { /* Wait for rest of cluster */ vp->v_cstart = lbn; bdwrite(bp); } } else if (lbn == vp->v_cstart + vp->v_clen) { /* * At end of cluster, write it out if seqcount tells us we * are operating sequentially, otherwise let the buf or * update daemon handle it. */ bdwrite(bp); if (seqcount > 1) cluster_wbuild_wb(vp, lblocksize, vp->v_cstart, vp->v_clen + 1); vp->v_clen = 0; vp->v_cstart = lbn + 1; } else if (vm_page_count_severe()) { /* * We are low on memory, get it going NOW */ bawrite(bp); } else { /* * In the middle of a cluster, so just delay the I/O for now. */ bdwrite(bp); } vp->v_lastw = lbn; vp->v_lasta = bp->b_blkno; } /* * This is an awful lot like cluster_rbuild...wish they could be combined. * The last lbn argument is the current block on which I/O is being * performed. Check to see that it doesn't fall in the middle of * the current block (if last_bp == NULL). */ int cluster_wbuild(vp, size, start_lbn, len) struct vnode *vp; long size; daddr_t start_lbn; int len; { struct buf *bp, *tbp; struct bufobj *bo; int i, j; int totalwritten = 0; int dbsize = btodb(size); bo = &vp->v_bufobj; while (len > 0) { /* * If the buffer is not delayed-write (i.e. dirty), or it * is delayed-write but either locked or inval, it cannot * partake in the clustered write. */ BO_LOCK(bo); if ((tbp = gbincore(&vp->v_bufobj, start_lbn)) == NULL || (tbp->b_vflags & BV_BKGRDINPROG)) { BO_UNLOCK(bo); ++start_lbn; --len; continue; } if (BUF_LOCK(tbp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, BO_MTX(bo))) { ++start_lbn; --len; continue; } if ((tbp->b_flags & (B_INVAL | B_DELWRI)) != B_DELWRI) { BUF_UNLOCK(tbp); ++start_lbn; --len; continue; } if (tbp->b_pin_count > 0) { BUF_UNLOCK(tbp); ++start_lbn; --len; continue; } bremfree(tbp); tbp->b_flags &= ~B_DONE; /* * Extra memory in the buffer, punt on this buffer. * XXX we could handle this in most cases, but we would * have to push the extra memory down to after our max * possible cluster size and then potentially pull it back * up if the cluster was terminated prematurely--too much * hassle. */ if (((tbp->b_flags & (B_CLUSTEROK | B_MALLOC | B_VMIO)) != (B_CLUSTEROK | B_VMIO)) || (tbp->b_bcount != tbp->b_bufsize) || (tbp->b_bcount != size) || (len == 1) || ((bp = getpbuf(&cluster_pbuf_freecnt)) == NULL)) { totalwritten += tbp->b_bufsize; bawrite(tbp); ++start_lbn; --len; continue; } /* * We got a pbuf to make the cluster in. * so initialise it. */ TAILQ_INIT(&bp->b_cluster.cluster_head); bp->b_bcount = 0; bp->b_bufsize = 0; bp->b_npages = 0; if (tbp->b_wcred != NOCRED) bp->b_wcred = crhold(tbp->b_wcred); bp->b_blkno = tbp->b_blkno; bp->b_lblkno = tbp->b_lblkno; bp->b_offset = tbp->b_offset; /* * We are synthesizing a buffer out of vm_page_t's, but * if the block size is not page aligned then the starting * address may not be either. Inherit the b_data offset * from the original buffer. */ bp->b_data = (char *)((vm_offset_t)bp->b_data | ((vm_offset_t)tbp->b_data & PAGE_MASK)); bp->b_flags |= B_CLUSTER | (tbp->b_flags & (B_VMIO | B_NEEDCOMMIT)); bp->b_iodone = cluster_callback; pbgetvp(vp, bp); /* * From this location in the file, scan forward to see * if there are buffers with adjacent data that need to * be written as well. */ for (i = 0; i < len; ++i, ++start_lbn) { if (i != 0) { /* If not the first buffer */ /* * If the adjacent data is not even in core it * can't need to be written. */ BO_LOCK(bo); if ((tbp = gbincore(bo, start_lbn)) == NULL || (tbp->b_vflags & BV_BKGRDINPROG)) { BO_UNLOCK(bo); break; } /* * If it IS in core, but has different * characteristics, or is locked (which * means it could be undergoing a background * I/O or be in a weird state), then don't * cluster with it. */ if (BUF_LOCK(tbp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, BO_MTX(bo))) break; if ((tbp->b_flags & (B_VMIO | B_CLUSTEROK | B_INVAL | B_DELWRI | B_NEEDCOMMIT)) != (B_DELWRI | B_CLUSTEROK | (bp->b_flags & (B_VMIO | B_NEEDCOMMIT))) || tbp->b_wcred != bp->b_wcred) { BUF_UNLOCK(tbp); break; } /* * Check that the combined cluster * would make sense with regard to pages * and would not be too large */ if ((tbp->b_bcount != size) || ((bp->b_blkno + (dbsize * i)) != tbp->b_blkno) || ((tbp->b_npages + bp->b_npages) > (vp->v_mount->mnt_iosize_max / PAGE_SIZE))) { BUF_UNLOCK(tbp); break; } /* * Do not pull in pinned buffers. */ if (tbp->b_pin_count > 0) { BUF_UNLOCK(tbp); break; } /* * Ok, it's passed all the tests, * so remove it from the free list * and mark it busy. We will use it. */ bremfree(tbp); tbp->b_flags &= ~B_DONE; } /* end of code for non-first buffers only */ /* * If the IO is via the VM then we do some * special VM hackery (yuck). Since the buffer's * block size may not be page-aligned it is possible * for a page to be shared between two buffers. We * have to get rid of the duplication when building * the cluster. */ if (tbp->b_flags & B_VMIO) { vm_page_t m; VM_OBJECT_LOCK(tbp->b_bufobj->bo_object); if (i != 0) { /* if not first buffer */ for (j = 0; j < tbp->b_npages; j += 1) { m = tbp->b_pages[j]; if (m->oflags & VPO_BUSY) { VM_OBJECT_UNLOCK( tbp->b_object); bqrelse(tbp); goto finishcluster; } } } for (j = 0; j < tbp->b_npages; j += 1) { m = tbp->b_pages[j]; vm_page_io_start(m); vm_object_pip_add(m->object, 1); if ((bp->b_npages == 0) || (bp->b_pages[bp->b_npages - 1] != m)) { bp->b_pages[bp->b_npages] = m; bp->b_npages++; } } VM_OBJECT_UNLOCK(tbp->b_bufobj->bo_object); } bp->b_bcount += size; bp->b_bufsize += size; /* * If any of the clustered buffers have their * B_BARRIER flag set, transfer that request to * the cluster. */ bp->b_flags |= (tbp->b_flags & B_BARRIER); tbp->b_flags &= ~(B_DONE | B_BARRIER); tbp->b_flags |= B_ASYNC; tbp->b_ioflags &= ~BIO_ERROR; tbp->b_iocmd = BIO_WRITE; bundirty(tbp); reassignbuf(tbp); /* put on clean list */ bufobj_wref(tbp->b_bufobj); BUF_KERNPROC(tbp); TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head, tbp, b_cluster.cluster_entry); } finishcluster: pmap_qenter(trunc_page((vm_offset_t) bp->b_data), (vm_page_t *) bp->b_pages, bp->b_npages); if (bp->b_bufsize > bp->b_kvasize) panic( "cluster_wbuild: b_bufsize(%ld) > b_kvasize(%d)\n", bp->b_bufsize, bp->b_kvasize); bp->b_kvasize = bp->b_bufsize; totalwritten += bp->b_bufsize; bp->b_dirtyoff = 0; bp->b_dirtyend = bp->b_bufsize; bawrite(bp); len -= i; } return totalwritten; } /* * Collect together all the buffers in a cluster. * Plus add one additional buffer. */ static struct cluster_save * cluster_collectbufs(vp, last_bp) struct vnode *vp; struct buf *last_bp; { struct cluster_save *buflist; struct buf *bp; daddr_t lbn; int i, len; len = vp->v_lastw - vp->v_cstart + 1; buflist = malloc(sizeof(struct buf *) * (len + 1) + sizeof(*buflist), M_SEGMENT, M_WAITOK); buflist->bs_nchildren = 0; buflist->bs_children = (struct buf **) (buflist + 1); for (lbn = vp->v_cstart, i = 0; i < len; lbn++, i++) { (void) bread(vp, lbn, last_bp->b_bcount, NOCRED, &bp); buflist->bs_children[i] = bp; if (bp->b_blkno == bp->b_lblkno) VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL, NULL); } buflist->bs_children[i] = bp = last_bp; if (bp->b_blkno == bp->b_lblkno) VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL, NULL); buflist->bs_nchildren = i + 1; return (buflist); } Index: stable/9/sys/ufs/ffs/ffs_balloc.c =================================================================== --- stable/9/sys/ufs/ffs/ffs_balloc.c (revision 250946) +++ stable/9/sys/ufs/ffs/ffs_balloc.c (revision 250947) @@ -1,1066 +1,1066 @@ /*- * Copyright (c) 2002 Networks Associates Technology, Inc. * All rights reserved. * * This software was developed for the FreeBSD Project by Marshall * Kirk McKusick and Network Associates Laboratories, the Security * Research Division of Network Associates, Inc. under DARPA/SPAWAR * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS * research program * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ffs_balloc.c 8.8 (Berkeley) 6/16/95 */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Balloc defines the structure of filesystem storage * by allocating the physical blocks on a device given * the inode and the logical block number in a file. * This is the allocation strategy for UFS1. Below is * the allocation strategy for UFS2. */ int ffs_balloc_ufs1(struct vnode *vp, off_t startoffset, int size, struct ucred *cred, int flags, struct buf **bpp) { struct inode *ip; struct ufs1_dinode *dp; ufs_lbn_t lbn, lastlbn; struct fs *fs; ufs1_daddr_t nb; struct buf *bp, *nbp; struct ufsmount *ump; struct indir indirs[NIADDR + 2]; int deallocated, osize, nsize, num, i, error; ufs2_daddr_t newb; ufs1_daddr_t *bap, pref; ufs1_daddr_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1]; ufs2_daddr_t *lbns_remfree, lbns[NIADDR + 1]; int unwindidx = -1; int saved_inbdflush; static struct timeval lastfail; static int curfail; int reclaimed; ip = VTOI(vp); dp = ip->i_din1; fs = ip->i_fs; ump = ip->i_ump; lbn = lblkno(fs, startoffset); size = blkoff(fs, startoffset) + size; reclaimed = 0; if (size > fs->fs_bsize) panic("ffs_balloc_ufs1: blk too big"); *bpp = NULL; if (flags & IO_EXT) return (EOPNOTSUPP); if (lbn < 0) return (EFBIG); if (DOINGSOFTDEP(vp)) softdep_prealloc(vp, MNT_WAIT); /* * If the next write will extend the file into a new block, * and the file is currently composed of a fragment * this fragment has to be extended to be a full block. */ lastlbn = lblkno(fs, ip->i_size); if (lastlbn < NDADDR && lastlbn < lbn) { nb = lastlbn; osize = blksize(fs, ip, nb); if (osize < fs->fs_bsize && osize > 0) { UFS_LOCK(ump); error = ffs_realloccg(ip, nb, dp->di_db[nb], ffs_blkpref_ufs1(ip, lastlbn, (int)nb, &dp->di_db[0]), osize, (int)fs->fs_bsize, flags, cred, &bp); if (error) return (error); if (DOINGSOFTDEP(vp)) softdep_setup_allocdirect(ip, nb, dbtofsb(fs, bp->b_blkno), dp->di_db[nb], fs->fs_bsize, osize, bp); ip->i_size = smalllblktosize(fs, nb + 1); dp->di_size = ip->i_size; dp->di_db[nb] = dbtofsb(fs, bp->b_blkno); ip->i_flag |= IN_CHANGE | IN_UPDATE; if (flags & IO_SYNC) bwrite(bp); else bawrite(bp); } } /* * The first NDADDR blocks are direct blocks */ if (lbn < NDADDR) { if (flags & BA_METAONLY) panic("ffs_balloc_ufs1: BA_METAONLY for direct block"); nb = dp->di_db[lbn]; if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) { error = bread(vp, lbn, fs->fs_bsize, NOCRED, &bp); if (error) { brelse(bp); return (error); } bp->b_blkno = fsbtodb(fs, nb); *bpp = bp; return (0); } if (nb != 0) { /* * Consider need to reallocate a fragment. */ osize = fragroundup(fs, blkoff(fs, ip->i_size)); nsize = fragroundup(fs, size); if (nsize <= osize) { error = bread(vp, lbn, osize, NOCRED, &bp); if (error) { brelse(bp); return (error); } bp->b_blkno = fsbtodb(fs, nb); } else { UFS_LOCK(ump); error = ffs_realloccg(ip, lbn, dp->di_db[lbn], ffs_blkpref_ufs1(ip, lbn, (int)lbn, &dp->di_db[0]), osize, nsize, flags, cred, &bp); if (error) return (error); if (DOINGSOFTDEP(vp)) softdep_setup_allocdirect(ip, lbn, dbtofsb(fs, bp->b_blkno), nb, nsize, osize, bp); } } else { if (ip->i_size < smalllblktosize(fs, lbn + 1)) nsize = fragroundup(fs, size); else nsize = fs->fs_bsize; UFS_LOCK(ump); error = ffs_alloc(ip, lbn, ffs_blkpref_ufs1(ip, lbn, (int)lbn, &dp->di_db[0]), nsize, flags, cred, &newb); if (error) return (error); bp = getblk(vp, lbn, nsize, 0, 0, 0); bp->b_blkno = fsbtodb(fs, newb); if (flags & BA_CLRBUF) vfs_bio_clrbuf(bp); if (DOINGSOFTDEP(vp)) softdep_setup_allocdirect(ip, lbn, newb, 0, nsize, 0, bp); } dp->di_db[lbn] = dbtofsb(fs, bp->b_blkno); ip->i_flag |= IN_CHANGE | IN_UPDATE; *bpp = bp; return (0); } /* * Determine the number of levels of indirection. */ pref = 0; if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0) return(error); #ifdef INVARIANTS if (num < 1) panic ("ffs_balloc_ufs1: ufs_getlbns returned indirect block"); #endif saved_inbdflush = curthread_pflags_set(TDP_INBDFLUSH); /* * Fetch the first indirect block allocating if necessary. */ --num; nb = dp->di_ib[indirs[0].in_off]; allocib = NULL; allocblk = allociblk; lbns_remfree = lbns; if (nb == 0) { UFS_LOCK(ump); pref = ffs_blkpref_ufs1(ip, lbn, -indirs[0].in_off - 1, (ufs1_daddr_t *)0); if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, flags, cred, &newb)) != 0) { curthread_pflags_restore(saved_inbdflush); return (error); } pref = newb + fs->fs_frag; nb = newb; *allocblk++ = nb; *lbns_remfree++ = indirs[1].in_lbn; bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0, 0); bp->b_blkno = fsbtodb(fs, nb); vfs_bio_clrbuf(bp); if (DOINGSOFTDEP(vp)) { softdep_setup_allocdirect(ip, NDADDR + indirs[0].in_off, newb, 0, fs->fs_bsize, 0, bp); bdwrite(bp); } else { /* * Write synchronously so that indirect blocks * never point at garbage. */ if (DOINGASYNC(vp)) bdwrite(bp); else if ((error = bwrite(bp)) != 0) goto fail; } allocib = &dp->di_ib[indirs[0].in_off]; *allocib = nb; ip->i_flag |= IN_CHANGE | IN_UPDATE; } /* * Fetch through the indirect blocks, allocating as necessary. */ retry: for (i = 1;;) { error = bread(vp, indirs[i].in_lbn, (int)fs->fs_bsize, NOCRED, &bp); if (error) { brelse(bp); goto fail; } bap = (ufs1_daddr_t *)bp->b_data; nb = bap[indirs[i].in_off]; if (i == num) break; i += 1; if (nb != 0) { bqrelse(bp); continue; } UFS_LOCK(ump); if (pref == 0) pref = ffs_blkpref_ufs1(ip, lbn, i - num - 1, (ufs1_daddr_t *)0); if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, flags | IO_BUFLOCKED, cred, &newb)) != 0) { brelse(bp); if (++reclaimed == 1) { UFS_LOCK(ump); softdep_request_cleanup(fs, vp, cred, FLUSH_BLOCKS_WAIT); UFS_UNLOCK(ump); goto retry; } if (ppsratecheck(&lastfail, &curfail, 1)) { ffs_fserr(fs, ip->i_number, "filesystem full"); uprintf("\n%s: write failed, filesystem " "is full\n", fs->fs_fsmnt); } goto fail; } pref = newb + fs->fs_frag; nb = newb; *allocblk++ = nb; *lbns_remfree++ = indirs[i].in_lbn; nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); vfs_bio_clrbuf(nbp); if (DOINGSOFTDEP(vp)) { softdep_setup_allocindir_meta(nbp, ip, bp, indirs[i - 1].in_off, nb); bdwrite(nbp); } else { /* * Write synchronously so that indirect blocks * never point at garbage. */ if ((error = bwrite(nbp)) != 0) { brelse(bp); goto fail; } } bap[indirs[i - 1].in_off] = nb; if (allocib == NULL && unwindidx < 0) unwindidx = i - 1; /* * If required, write synchronously, otherwise use * delayed write. */ if (flags & IO_SYNC) { bwrite(bp); } else { if (bp->b_bufsize == fs->fs_bsize) bp->b_flags |= B_CLUSTEROK; bdwrite(bp); } } /* * If asked only for the indirect block, then return it. */ if (flags & BA_METAONLY) { curthread_pflags_restore(saved_inbdflush); *bpp = bp; return (0); } /* * Get the data block, allocating if necessary. */ if (nb == 0) { UFS_LOCK(ump); if (pref == 0) pref = ffs_blkpref_ufs1(ip, lbn, indirs[i].in_off, &bap[0]); error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, flags | IO_BUFLOCKED, cred, &newb); if (error) { brelse(bp); if (++reclaimed == 1) { UFS_LOCK(ump); softdep_request_cleanup(fs, vp, cred, FLUSH_BLOCKS_WAIT); UFS_UNLOCK(ump); goto retry; } if (ppsratecheck(&lastfail, &curfail, 1)) { ffs_fserr(fs, ip->i_number, "filesystem full"); uprintf("\n%s: write failed, filesystem " "is full\n", fs->fs_fsmnt); } goto fail; } nb = newb; *allocblk++ = nb; *lbns_remfree++ = lbn; nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); if (flags & BA_CLRBUF) vfs_bio_clrbuf(nbp); if (DOINGSOFTDEP(vp)) softdep_setup_allocindir_page(ip, lbn, bp, indirs[i].in_off, nb, 0, nbp); bap[indirs[i].in_off] = nb; /* * If required, write synchronously, otherwise use * delayed write. */ if (flags & IO_SYNC) { bwrite(bp); } else { if (bp->b_bufsize == fs->fs_bsize) bp->b_flags |= B_CLUSTEROK; bdwrite(bp); } curthread_pflags_restore(saved_inbdflush); *bpp = nbp; return (0); } brelse(bp); if (flags & BA_CLRBUF) { int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT; if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) { error = cluster_read(vp, ip->i_size, lbn, (int)fs->fs_bsize, NOCRED, MAXBSIZE, seqcount, &nbp); } else { error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp); } if (error) { brelse(nbp); goto fail; } } else { nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); } curthread_pflags_restore(saved_inbdflush); *bpp = nbp; return (0); fail: curthread_pflags_restore(saved_inbdflush); /* * If we have failed to allocate any blocks, simply return the error. * This is the usual case and avoids the need to fsync the file. */ if (allocblk == allociblk && allocib == NULL && unwindidx == -1) return (error); /* * If we have failed part way through block allocation, we * have to deallocate any indirect blocks that we have allocated. * We have to fsync the file before we start to get rid of all * of its dependencies so that we do not leave them dangling. * We have to sync it at the end so that the soft updates code * does not find any untracked changes. Although this is really * slow, running out of disk space is not expected to be a common * occurence. The error return from fsync is ignored as we already * have an error to return to the user. * * XXX Still have to journal the free below */ (void) ffs_syncvnode(vp, MNT_WAIT, 0); for (deallocated = 0, blkp = allociblk, lbns_remfree = lbns; blkp < allocblk; blkp++, lbns_remfree++) { /* * We shall not leave the freed blocks on the vnode * buffer object lists. */ bp = getblk(vp, *lbns_remfree, fs->fs_bsize, 0, 0, GB_NOCREAT); if (bp != NULL) { bp->b_flags |= (B_INVAL | B_RELBUF); bp->b_flags &= ~B_ASYNC; brelse(bp); } deallocated += fs->fs_bsize; } if (allocib != NULL) { *allocib = 0; } else if (unwindidx >= 0) { int r; r = bread(vp, indirs[unwindidx].in_lbn, (int)fs->fs_bsize, NOCRED, &bp); if (r) { panic("Could not unwind indirect block, error %d", r); brelse(bp); } else { bap = (ufs1_daddr_t *)bp->b_data; bap[indirs[unwindidx].in_off] = 0; if (flags & IO_SYNC) { bwrite(bp); } else { if (bp->b_bufsize == fs->fs_bsize) bp->b_flags |= B_CLUSTEROK; bdwrite(bp); } } } if (deallocated) { #ifdef QUOTA /* * Restore user's disk quota because allocation failed. */ (void) chkdq(ip, -btodb(deallocated), cred, FORCE); #endif dp->di_blocks -= btodb(deallocated); ip->i_flag |= IN_CHANGE | IN_UPDATE; } (void) ffs_syncvnode(vp, MNT_WAIT, 0); /* * After the buffers are invalidated and on-disk pointers are * cleared, free the blocks. */ for (blkp = allociblk; blkp < allocblk; blkp++) { ffs_blkfree(ump, fs, ip->i_devvp, *blkp, fs->fs_bsize, ip->i_number, vp->v_type, NULL); } return (error); } /* * Balloc defines the structure of file system storage * by allocating the physical blocks on a device given * the inode and the logical block number in a file. * This is the allocation strategy for UFS2. Above is * the allocation strategy for UFS1. */ int ffs_balloc_ufs2(struct vnode *vp, off_t startoffset, int size, struct ucred *cred, int flags, struct buf **bpp) { struct inode *ip; struct ufs2_dinode *dp; ufs_lbn_t lbn, lastlbn; struct fs *fs; struct buf *bp, *nbp; struct ufsmount *ump; struct indir indirs[NIADDR + 2]; ufs2_daddr_t nb, newb, *bap, pref; ufs2_daddr_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1]; ufs2_daddr_t *lbns_remfree, lbns[NIADDR + 1]; int deallocated, osize, nsize, num, i, error; int unwindidx = -1; int saved_inbdflush; static struct timeval lastfail; static int curfail; int reclaimed; ip = VTOI(vp); dp = ip->i_din2; fs = ip->i_fs; ump = ip->i_ump; lbn = lblkno(fs, startoffset); size = blkoff(fs, startoffset) + size; reclaimed = 0; if (size > fs->fs_bsize) panic("ffs_balloc_ufs2: blk too big"); *bpp = NULL; if (lbn < 0) return (EFBIG); if (DOINGSOFTDEP(vp)) softdep_prealloc(vp, MNT_WAIT); /* * Check for allocating external data. */ if (flags & IO_EXT) { if (lbn >= NXADDR) return (EFBIG); /* * If the next write will extend the data into a new block, * and the data is currently composed of a fragment * this fragment has to be extended to be a full block. */ lastlbn = lblkno(fs, dp->di_extsize); if (lastlbn < lbn) { nb = lastlbn; osize = sblksize(fs, dp->di_extsize, nb); if (osize < fs->fs_bsize && osize > 0) { UFS_LOCK(ump); error = ffs_realloccg(ip, -1 - nb, dp->di_extb[nb], ffs_blkpref_ufs2(ip, lastlbn, (int)nb, &dp->di_extb[0]), osize, (int)fs->fs_bsize, flags, cred, &bp); if (error) return (error); if (DOINGSOFTDEP(vp)) softdep_setup_allocext(ip, nb, dbtofsb(fs, bp->b_blkno), dp->di_extb[nb], fs->fs_bsize, osize, bp); dp->di_extsize = smalllblktosize(fs, nb + 1); dp->di_extb[nb] = dbtofsb(fs, bp->b_blkno); bp->b_xflags |= BX_ALTDATA; ip->i_flag |= IN_CHANGE; if (flags & IO_SYNC) bwrite(bp); else bawrite(bp); } } /* * All blocks are direct blocks */ if (flags & BA_METAONLY) panic("ffs_balloc_ufs2: BA_METAONLY for ext block"); nb = dp->di_extb[lbn]; if (nb != 0 && dp->di_extsize >= smalllblktosize(fs, lbn + 1)) { error = bread(vp, -1 - lbn, fs->fs_bsize, NOCRED, &bp); if (error) { brelse(bp); return (error); } bp->b_blkno = fsbtodb(fs, nb); bp->b_xflags |= BX_ALTDATA; *bpp = bp; return (0); } if (nb != 0) { /* * Consider need to reallocate a fragment. */ osize = fragroundup(fs, blkoff(fs, dp->di_extsize)); nsize = fragroundup(fs, size); if (nsize <= osize) { error = bread(vp, -1 - lbn, osize, NOCRED, &bp); if (error) { brelse(bp); return (error); } bp->b_blkno = fsbtodb(fs, nb); bp->b_xflags |= BX_ALTDATA; } else { UFS_LOCK(ump); error = ffs_realloccg(ip, -1 - lbn, dp->di_extb[lbn], ffs_blkpref_ufs2(ip, lbn, (int)lbn, &dp->di_extb[0]), osize, nsize, flags, cred, &bp); if (error) return (error); bp->b_xflags |= BX_ALTDATA; if (DOINGSOFTDEP(vp)) softdep_setup_allocext(ip, lbn, dbtofsb(fs, bp->b_blkno), nb, nsize, osize, bp); } } else { if (dp->di_extsize < smalllblktosize(fs, lbn + 1)) nsize = fragroundup(fs, size); else nsize = fs->fs_bsize; UFS_LOCK(ump); error = ffs_alloc(ip, lbn, ffs_blkpref_ufs2(ip, lbn, (int)lbn, &dp->di_extb[0]), nsize, flags, cred, &newb); if (error) return (error); bp = getblk(vp, -1 - lbn, nsize, 0, 0, 0); bp->b_blkno = fsbtodb(fs, newb); bp->b_xflags |= BX_ALTDATA; if (flags & BA_CLRBUF) vfs_bio_clrbuf(bp); if (DOINGSOFTDEP(vp)) softdep_setup_allocext(ip, lbn, newb, 0, nsize, 0, bp); } dp->di_extb[lbn] = dbtofsb(fs, bp->b_blkno); ip->i_flag |= IN_CHANGE; *bpp = bp; return (0); } /* * If the next write will extend the file into a new block, * and the file is currently composed of a fragment * this fragment has to be extended to be a full block. */ lastlbn = lblkno(fs, ip->i_size); if (lastlbn < NDADDR && lastlbn < lbn) { nb = lastlbn; osize = blksize(fs, ip, nb); if (osize < fs->fs_bsize && osize > 0) { UFS_LOCK(ump); error = ffs_realloccg(ip, nb, dp->di_db[nb], - ffs_blkpref_ufs2(ip, lastlbn, (int)nb, - &dp->di_db[0]), osize, (int)fs->fs_bsize, - flags, cred, &bp); + ffs_blkpref_ufs2(ip, lastlbn, (int)nb, + &dp->di_db[0]), osize, (int)fs->fs_bsize, + flags, cred, &bp); if (error) return (error); if (DOINGSOFTDEP(vp)) softdep_setup_allocdirect(ip, nb, dbtofsb(fs, bp->b_blkno), dp->di_db[nb], fs->fs_bsize, osize, bp); ip->i_size = smalllblktosize(fs, nb + 1); dp->di_size = ip->i_size; dp->di_db[nb] = dbtofsb(fs, bp->b_blkno); ip->i_flag |= IN_CHANGE | IN_UPDATE; if (flags & IO_SYNC) bwrite(bp); else bawrite(bp); } } /* * The first NDADDR blocks are direct blocks */ if (lbn < NDADDR) { if (flags & BA_METAONLY) panic("ffs_balloc_ufs2: BA_METAONLY for direct block"); nb = dp->di_db[lbn]; if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) { error = bread(vp, lbn, fs->fs_bsize, NOCRED, &bp); if (error) { brelse(bp); return (error); } bp->b_blkno = fsbtodb(fs, nb); *bpp = bp; return (0); } if (nb != 0) { /* * Consider need to reallocate a fragment. */ osize = fragroundup(fs, blkoff(fs, ip->i_size)); nsize = fragroundup(fs, size); if (nsize <= osize) { error = bread(vp, lbn, osize, NOCRED, &bp); if (error) { brelse(bp); return (error); } bp->b_blkno = fsbtodb(fs, nb); } else { UFS_LOCK(ump); error = ffs_realloccg(ip, lbn, dp->di_db[lbn], ffs_blkpref_ufs2(ip, lbn, (int)lbn, - &dp->di_db[0]), osize, nsize, flags, + &dp->di_db[0]), osize, nsize, flags, cred, &bp); if (error) return (error); if (DOINGSOFTDEP(vp)) softdep_setup_allocdirect(ip, lbn, dbtofsb(fs, bp->b_blkno), nb, nsize, osize, bp); } } else { if (ip->i_size < smalllblktosize(fs, lbn + 1)) nsize = fragroundup(fs, size); else nsize = fs->fs_bsize; UFS_LOCK(ump); error = ffs_alloc(ip, lbn, ffs_blkpref_ufs2(ip, lbn, (int)lbn, &dp->di_db[0]), nsize, flags, cred, &newb); if (error) return (error); bp = getblk(vp, lbn, nsize, 0, 0, 0); bp->b_blkno = fsbtodb(fs, newb); if (flags & BA_CLRBUF) vfs_bio_clrbuf(bp); if (DOINGSOFTDEP(vp)) softdep_setup_allocdirect(ip, lbn, newb, 0, nsize, 0, bp); } dp->di_db[lbn] = dbtofsb(fs, bp->b_blkno); ip->i_flag |= IN_CHANGE | IN_UPDATE; *bpp = bp; return (0); } /* * Determine the number of levels of indirection. */ pref = 0; if ((error = ufs_getlbns(vp, lbn, indirs, &num)) != 0) return(error); #ifdef INVARIANTS if (num < 1) panic ("ffs_balloc_ufs2: ufs_getlbns returned indirect block"); #endif saved_inbdflush = curthread_pflags_set(TDP_INBDFLUSH); /* * Fetch the first indirect block allocating if necessary. */ --num; nb = dp->di_ib[indirs[0].in_off]; allocib = NULL; allocblk = allociblk; lbns_remfree = lbns; if (nb == 0) { UFS_LOCK(ump); pref = ffs_blkpref_ufs2(ip, lbn, -indirs[0].in_off - 1, (ufs2_daddr_t *)0); if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, flags, cred, &newb)) != 0) { curthread_pflags_restore(saved_inbdflush); return (error); } pref = newb + fs->fs_frag; nb = newb; *allocblk++ = nb; *lbns_remfree++ = indirs[1].in_lbn; bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0, 0); bp->b_blkno = fsbtodb(fs, nb); vfs_bio_clrbuf(bp); if (DOINGSOFTDEP(vp)) { softdep_setup_allocdirect(ip, NDADDR + indirs[0].in_off, newb, 0, fs->fs_bsize, 0, bp); bdwrite(bp); } else { /* * Write synchronously so that indirect blocks * never point at garbage. */ if (DOINGASYNC(vp)) bdwrite(bp); else if ((error = bwrite(bp)) != 0) goto fail; } allocib = &dp->di_ib[indirs[0].in_off]; *allocib = nb; ip->i_flag |= IN_CHANGE | IN_UPDATE; } /* * Fetch through the indirect blocks, allocating as necessary. */ retry: for (i = 1;;) { error = bread(vp, indirs[i].in_lbn, (int)fs->fs_bsize, NOCRED, &bp); if (error) { brelse(bp); goto fail; } bap = (ufs2_daddr_t *)bp->b_data; nb = bap[indirs[i].in_off]; if (i == num) break; i += 1; if (nb != 0) { bqrelse(bp); continue; } UFS_LOCK(ump); if (pref == 0) pref = ffs_blkpref_ufs2(ip, lbn, i - num - 1, (ufs2_daddr_t *)0); if ((error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, flags | IO_BUFLOCKED, cred, &newb)) != 0) { brelse(bp); if (++reclaimed == 1) { UFS_LOCK(ump); softdep_request_cleanup(fs, vp, cred, FLUSH_BLOCKS_WAIT); UFS_UNLOCK(ump); goto retry; } if (ppsratecheck(&lastfail, &curfail, 1)) { ffs_fserr(fs, ip->i_number, "filesystem full"); uprintf("\n%s: write failed, filesystem " "is full\n", fs->fs_fsmnt); } goto fail; } pref = newb + fs->fs_frag; nb = newb; *allocblk++ = nb; *lbns_remfree++ = indirs[i].in_lbn; nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); vfs_bio_clrbuf(nbp); if (DOINGSOFTDEP(vp)) { softdep_setup_allocindir_meta(nbp, ip, bp, indirs[i - 1].in_off, nb); bdwrite(nbp); } else { /* * Write synchronously so that indirect blocks * never point at garbage. */ if ((error = bwrite(nbp)) != 0) { brelse(bp); goto fail; } } bap[indirs[i - 1].in_off] = nb; if (allocib == NULL && unwindidx < 0) unwindidx = i - 1; /* * If required, write synchronously, otherwise use * delayed write. */ if (flags & IO_SYNC) { bwrite(bp); } else { if (bp->b_bufsize == fs->fs_bsize) bp->b_flags |= B_CLUSTEROK; bdwrite(bp); } } /* * If asked only for the indirect block, then return it. */ if (flags & BA_METAONLY) { curthread_pflags_restore(saved_inbdflush); *bpp = bp; return (0); } /* * Get the data block, allocating if necessary. */ if (nb == 0) { UFS_LOCK(ump); if (pref == 0) pref = ffs_blkpref_ufs2(ip, lbn, indirs[i].in_off, &bap[0]); error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, flags | IO_BUFLOCKED, cred, &newb); if (error) { brelse(bp); if (++reclaimed == 1) { UFS_LOCK(ump); softdep_request_cleanup(fs, vp, cred, FLUSH_BLOCKS_WAIT); UFS_UNLOCK(ump); goto retry; } if (ppsratecheck(&lastfail, &curfail, 1)) { ffs_fserr(fs, ip->i_number, "filesystem full"); uprintf("\n%s: write failed, filesystem " "is full\n", fs->fs_fsmnt); } goto fail; } nb = newb; *allocblk++ = nb; *lbns_remfree++ = lbn; nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); if (flags & BA_CLRBUF) vfs_bio_clrbuf(nbp); if (DOINGSOFTDEP(vp)) softdep_setup_allocindir_page(ip, lbn, bp, indirs[i].in_off, nb, 0, nbp); bap[indirs[i].in_off] = nb; /* * If required, write synchronously, otherwise use * delayed write. */ if (flags & IO_SYNC) { bwrite(bp); } else { if (bp->b_bufsize == fs->fs_bsize) bp->b_flags |= B_CLUSTEROK; bdwrite(bp); } curthread_pflags_restore(saved_inbdflush); *bpp = nbp; return (0); } brelse(bp); /* * If requested clear invalid portions of the buffer. If we * have to do a read-before-write (typical if BA_CLRBUF is set), * try to do some read-ahead in the sequential case to reduce * the number of I/O transactions. */ if (flags & BA_CLRBUF) { int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT; if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) { error = cluster_read(vp, ip->i_size, lbn, (int)fs->fs_bsize, NOCRED, MAXBSIZE, seqcount, &nbp); } else { error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp); } if (error) { brelse(nbp); goto fail; } } else { nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0, 0); nbp->b_blkno = fsbtodb(fs, nb); } curthread_pflags_restore(saved_inbdflush); *bpp = nbp; return (0); fail: curthread_pflags_restore(saved_inbdflush); /* * If we have failed to allocate any blocks, simply return the error. * This is the usual case and avoids the need to fsync the file. */ if (allocblk == allociblk && allocib == NULL && unwindidx == -1) return (error); /* * If we have failed part way through block allocation, we * have to deallocate any indirect blocks that we have allocated. * We have to fsync the file before we start to get rid of all * of its dependencies so that we do not leave them dangling. * We have to sync it at the end so that the soft updates code * does not find any untracked changes. Although this is really * slow, running out of disk space is not expected to be a common * occurence. The error return from fsync is ignored as we already * have an error to return to the user. * * XXX Still have to journal the free below */ (void) ffs_syncvnode(vp, MNT_WAIT, 0); for (deallocated = 0, blkp = allociblk, lbns_remfree = lbns; blkp < allocblk; blkp++, lbns_remfree++) { /* * We shall not leave the freed blocks on the vnode * buffer object lists. */ bp = getblk(vp, *lbns_remfree, fs->fs_bsize, 0, 0, GB_NOCREAT); if (bp != NULL) { bp->b_flags |= (B_INVAL | B_RELBUF); bp->b_flags &= ~B_ASYNC; brelse(bp); } deallocated += fs->fs_bsize; } if (allocib != NULL) { *allocib = 0; } else if (unwindidx >= 0) { int r; r = bread(vp, indirs[unwindidx].in_lbn, (int)fs->fs_bsize, NOCRED, &bp); if (r) { panic("Could not unwind indirect block, error %d", r); brelse(bp); } else { bap = (ufs2_daddr_t *)bp->b_data; bap[indirs[unwindidx].in_off] = 0; if (flags & IO_SYNC) { bwrite(bp); } else { if (bp->b_bufsize == fs->fs_bsize) bp->b_flags |= B_CLUSTEROK; bdwrite(bp); } } } if (deallocated) { #ifdef QUOTA /* * Restore user's disk quota because allocation failed. */ (void) chkdq(ip, -btodb(deallocated), cred, FORCE); #endif dp->di_blocks -= btodb(deallocated); ip->i_flag |= IN_CHANGE | IN_UPDATE; } (void) ffs_syncvnode(vp, MNT_WAIT, 0); /* * After the buffers are invalidated and on-disk pointers are * cleared, free the blocks. */ for (blkp = allociblk; blkp < allocblk; blkp++) { ffs_blkfree(ump, fs, ip->i_devvp, *blkp, fs->fs_bsize, ip->i_number, vp->v_type, NULL); } return (error); } Index: stable/9/sys/vm/vnode_pager.c =================================================================== --- stable/9/sys/vm/vnode_pager.c (revision 250946) +++ stable/9/sys/vm/vnode_pager.c (revision 250947) @@ -1,1283 +1,1283 @@ /*- * Copyright (c) 1990 University of Utah. * Copyright (c) 1991 The Regents of the University of California. * All rights reserved. * Copyright (c) 1993, 1994 John S. Dyson * Copyright (c) 1995, David Greenman * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)vnode_pager.c 7.5 (Berkeley) 4/20/91 */ /* * Page to/from files (vnodes). */ /* * TODO: * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will * greatly re-simplify the vnode_pager. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, int *run); static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m); static int vnode_pager_input_old(vm_object_t object, vm_page_t m); static void vnode_pager_dealloc(vm_object_t); static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int); static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *); static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t, struct ucred *cred); struct pagerops vnodepagerops = { .pgo_alloc = vnode_pager_alloc, .pgo_dealloc = vnode_pager_dealloc, .pgo_getpages = vnode_pager_getpages, .pgo_putpages = vnode_pager_putpages, .pgo_haspage = vnode_pager_haspage, }; int vnode_pbuf_freecnt; /* Create the VM system backing object for this vnode */ int vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td) { vm_object_t object; vm_ooffset_t size = isize; struct vattr va; if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE) return (0); while ((object = vp->v_object) != NULL) { VM_OBJECT_LOCK(object); if (!(object->flags & OBJ_DEAD)) { VM_OBJECT_UNLOCK(object); return (0); } VOP_UNLOCK(vp, 0); vm_object_set_flag(object, OBJ_DISCONNECTWNT); msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vodead", 0); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } if (size == 0) { if (vn_isdisk(vp, NULL)) { size = IDX_TO_OFF(INT_MAX); } else { if (VOP_GETATTR(vp, &va, td->td_ucred)) return (0); size = va.va_size; } } object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred); /* * Dereference the reference we just created. This assumes * that the object is associated with the vp. */ VM_OBJECT_LOCK(object); object->ref_count--; VM_OBJECT_UNLOCK(object); vrele(vp); KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object")); return (0); } void vnode_destroy_vobject(struct vnode *vp) { struct vm_object *obj; obj = vp->v_object; if (obj == NULL) return; ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject"); VM_OBJECT_LOCK(obj); if (obj->ref_count == 0) { /* * vclean() may be called twice. The first time * removes the primary reference to the object, * the second time goes one further and is a * special-case to terminate the object. * * don't double-terminate the object */ if ((obj->flags & OBJ_DEAD) == 0) vm_object_terminate(obj); else VM_OBJECT_UNLOCK(obj); } else { /* * Woe to the process that tries to page now :-). */ vm_pager_deallocate(obj); VM_OBJECT_UNLOCK(obj); } vp->v_object = NULL; } /* * Allocate (or lookup) pager for a vnode. * Handle is a vnode pointer. * * MPSAFE */ vm_object_t vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t offset, struct ucred *cred) { vm_object_t object; struct vnode *vp; /* * Pageout to vnode, no can do yet. */ if (handle == NULL) return (NULL); vp = (struct vnode *) handle; /* * If the object is being terminated, wait for it to * go away. */ retry: while ((object = vp->v_object) != NULL) { VM_OBJECT_LOCK(object); if ((object->flags & OBJ_DEAD) == 0) break; vm_object_set_flag(object, OBJ_DISCONNECTWNT); msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vadead", 0); } KASSERT(vp->v_usecount != 0, ("vnode_pager_alloc: no vnode reference")); if (object == NULL) { /* * Add an object of the appropriate size */ object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size))); object->un_pager.vnp.vnp_size = size; object->un_pager.vnp.writemappings = 0; object->handle = handle; VI_LOCK(vp); if (vp->v_object != NULL) { /* * Object has been created while we were sleeping */ VI_UNLOCK(vp); vm_object_destroy(object); goto retry; } vp->v_object = object; VI_UNLOCK(vp); } else { object->ref_count++; VM_OBJECT_UNLOCK(object); } vref(vp); return (object); } /* * The object must be locked. */ static void vnode_pager_dealloc(object) vm_object_t object; { struct vnode *vp; int refs; vp = object->handle; if (vp == NULL) panic("vnode_pager_dealloc: pager already dealloced"); VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); vm_object_pip_wait(object, "vnpdea"); refs = object->ref_count; object->handle = NULL; object->type = OBJT_DEAD; if (object->flags & OBJ_DISCONNECTWNT) { vm_object_clear_flag(object, OBJ_DISCONNECTWNT); wakeup(object); } ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc"); if (object->un_pager.vnp.writemappings > 0) { object->un_pager.vnp.writemappings = 0; VOP_ADD_WRITECOUNT(vp, -1); } vp->v_object = NULL; VOP_UNSET_TEXT(vp); VM_OBJECT_UNLOCK(object); while (refs-- > 0) vunref(vp); VM_OBJECT_LOCK(object); } static boolean_t vnode_pager_haspage(object, pindex, before, after) vm_object_t object; vm_pindex_t pindex; int *before; int *after; { struct vnode *vp = object->handle; daddr_t bn; int err; daddr_t reqblock; int poff; int bsize; int pagesperblock, blocksperpage; int vfslocked; VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); /* * If no vp or vp is doomed or marked transparent to VM, we do not * have the page. */ if (vp == NULL || vp->v_iflag & VI_DOOMED) return FALSE; /* * If the offset is beyond end of file we do * not have the page. */ if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size) return FALSE; bsize = vp->v_mount->mnt_stat.f_iosize; pagesperblock = bsize / PAGE_SIZE; blocksperpage = 0; if (pagesperblock > 0) { reqblock = pindex / pagesperblock; } else { blocksperpage = (PAGE_SIZE / bsize); reqblock = pindex * blocksperpage; } VM_OBJECT_UNLOCK(object); vfslocked = VFS_LOCK_GIANT(vp->v_mount); err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before); VFS_UNLOCK_GIANT(vfslocked); VM_OBJECT_LOCK(object); if (err) return TRUE; if (bn == -1) return FALSE; if (pagesperblock > 0) { poff = pindex - (reqblock * pagesperblock); if (before) { *before *= pagesperblock; *before += poff; } if (after) { int numafter; *after *= pagesperblock; numafter = pagesperblock - (poff + 1); if (IDX_TO_OFF(pindex + numafter) > object->un_pager.vnp.vnp_size) { numafter = OFF_TO_IDX(object->un_pager.vnp.vnp_size) - pindex; } *after += numafter; } } else { if (before) { *before /= blocksperpage; } if (after) { *after /= blocksperpage; } } return TRUE; } /* * Lets the VM system know about a change in size for a file. * We adjust our own internal size and flush any cached pages in * the associated object that are affected by the size change. * * Note: this routine may be invoked as a result of a pager put * operation (possibly at object termination time), so we must be careful. */ void vnode_pager_setsize(vp, nsize) struct vnode *vp; vm_ooffset_t nsize; { vm_object_t object; vm_page_t m; vm_pindex_t nobjsize; if ((object = vp->v_object) == NULL) return; /* ASSERT_VOP_ELOCKED(vp, "vnode_pager_setsize and not locked vnode"); */ VM_OBJECT_LOCK(object); if (object->type == OBJT_DEAD) { VM_OBJECT_UNLOCK(object); return; } KASSERT(object->type == OBJT_VNODE, ("not vnode-backed object %p", object)); if (nsize == object->un_pager.vnp.vnp_size) { /* * Hasn't changed size */ VM_OBJECT_UNLOCK(object); return; } nobjsize = OFF_TO_IDX(nsize + PAGE_MASK); if (nsize < object->un_pager.vnp.vnp_size) { /* * File has shrunk. Toss any cached pages beyond the new EOF. */ if (nobjsize < object->size) vm_object_page_remove(object, nobjsize, object->size, 0); /* * this gets rid of garbage at the end of a page that is now * only partially backed by the vnode. * * XXX for some reason (I don't know yet), if we take a * completely invalid page and mark it partially valid * it can screw up NFS reads, so we don't allow the case. */ if ((nsize & PAGE_MASK) && (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL && m->valid != 0) { int base = (int)nsize & PAGE_MASK; int size = PAGE_SIZE - base; /* * Clear out partial-page garbage in case * the page has been mapped. */ pmap_zero_page_area(m, base, size); /* * Update the valid bits to reflect the blocks that * have been zeroed. Some of these valid bits may * have already been set. */ vm_page_set_valid(m, base, size); /* * Round "base" to the next block boundary so that the * dirty bit for a partially zeroed block is not * cleared. */ base = roundup2(base, DEV_BSIZE); /* * Clear out partial-page dirty bits. * * note that we do not clear out the valid * bits. This would prevent bogus_page * replacement from working properly. */ vm_page_clear_dirty(m, base, PAGE_SIZE - base); } else if ((nsize & PAGE_MASK) && __predict_false(object->cache != NULL)) { vm_page_cache_free(object, OFF_TO_IDX(nsize), nobjsize); } } object->un_pager.vnp.vnp_size = nsize; object->size = nobjsize; VM_OBJECT_UNLOCK(object); } /* * calculate the linear (byte) disk address of specified virtual * file address */ static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress, int *run) { int bsize; int err; daddr_t vblock; daddr_t voffset; if (address < 0) return -1; if (vp->v_iflag & VI_DOOMED) return -1; bsize = vp->v_mount->mnt_stat.f_iosize; vblock = address / bsize; voffset = address % bsize; err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL); if (err == 0) { if (*rtaddress != -1) *rtaddress += voffset / DEV_BSIZE; if (run) { *run += 1; *run *= bsize/PAGE_SIZE; *run -= voffset/PAGE_SIZE; } } return (err); } /* * small block filesystem vnode pager input */ static int vnode_pager_input_smlfs(object, m) vm_object_t object; vm_page_t m; { struct vnode *vp; struct bufobj *bo; struct buf *bp; struct sf_buf *sf; daddr_t fileaddr; vm_offset_t bsize; vm_page_bits_t bits; int error, i; error = 0; vp = object->handle; if (vp->v_iflag & VI_DOOMED) return VM_PAGER_BAD; bsize = vp->v_mount->mnt_stat.f_iosize; VOP_BMAP(vp, 0, &bo, 0, NULL, NULL); sf = sf_buf_alloc(m, 0); for (i = 0; i < PAGE_SIZE / bsize; i++) { vm_ooffset_t address; bits = vm_page_bits(i * bsize, bsize); if (m->valid & bits) continue; address = IDX_TO_OFF(m->pindex) + i * bsize; if (address >= object->un_pager.vnp.vnp_size) { fileaddr = -1; } else { error = vnode_pager_addr(vp, address, &fileaddr, NULL); if (error) break; } if (fileaddr != -1) { bp = getpbuf(&vnode_pbuf_freecnt); /* build a minimal buffer header */ bp->b_iocmd = BIO_READ; bp->b_iodone = bdone; KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); bp->b_rcred = crhold(curthread->td_ucred); bp->b_wcred = crhold(curthread->td_ucred); bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize; bp->b_blkno = fileaddr; pbgetbo(bo, bp); bp->b_vp = vp; bp->b_bcount = bsize; bp->b_bufsize = bsize; bp->b_runningbufspace = bp->b_bufsize; atomic_add_long(&runningbufspace, bp->b_runningbufspace); /* do the input */ bp->b_iooffset = dbtob(bp->b_blkno); bstrategy(bp); bwait(bp, PVM, "vnsrd"); if ((bp->b_ioflags & BIO_ERROR) != 0) error = EIO; /* * free the buffer header back to the swap buffer pool */ bp->b_vp = NULL; pbrelbo(bp); relpbuf(bp, &vnode_pbuf_freecnt); if (error) break; } else bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize); KASSERT((m->dirty & bits) == 0, ("vnode_pager_input_smlfs: page %p is dirty", m)); VM_OBJECT_LOCK(object); m->valid |= bits; VM_OBJECT_UNLOCK(object); } sf_buf_free(sf); if (error) { return VM_PAGER_ERROR; } return VM_PAGER_OK; } /* * old style vnode pager input routine */ static int vnode_pager_input_old(object, m) vm_object_t object; vm_page_t m; { struct uio auio; struct iovec aiov; int error; int size; struct sf_buf *sf; struct vnode *vp; VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); error = 0; /* * Return failure if beyond current EOF */ if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) { return VM_PAGER_BAD; } else { size = PAGE_SIZE; if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size) size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex); vp = object->handle; VM_OBJECT_UNLOCK(object); /* * Allocate a kernel virtual address and initialize so that * we can use VOP_READ/WRITE routines. */ sf = sf_buf_alloc(m, 0); aiov.iov_base = (caddr_t)sf_buf_kva(sf); aiov.iov_len = size; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = IDX_TO_OFF(m->pindex); auio.uio_segflg = UIO_SYSSPACE; auio.uio_rw = UIO_READ; auio.uio_resid = size; auio.uio_td = curthread; error = VOP_READ(vp, &auio, 0, curthread->td_ucred); if (!error) { int count = size - auio.uio_resid; if (count == 0) error = EINVAL; else if (count != PAGE_SIZE) bzero((caddr_t)sf_buf_kva(sf) + count, PAGE_SIZE - count); } sf_buf_free(sf); VM_OBJECT_LOCK(object); } KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m)); if (!error) m->valid = VM_PAGE_BITS_ALL; return error ? VM_PAGER_ERROR : VM_PAGER_OK; } /* * generic vnode pager input routine */ /* * Local media VFS's that do not implement their own VOP_GETPAGES * should have their VOP_GETPAGES call to vnode_pager_generic_getpages() * to implement the previous behaviour. * * All other FS's should use the bypass to get to the local media * backing vp's VOP_GETPAGES. */ static int vnode_pager_getpages(object, m, count, reqpage) vm_object_t object; vm_page_t *m; int count; int reqpage; { int rtval; struct vnode *vp; int bytes = count * PAGE_SIZE; int vfslocked; vp = object->handle; VM_OBJECT_UNLOCK(object); vfslocked = VFS_LOCK_GIANT(vp->v_mount); rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0); KASSERT(rtval != EOPNOTSUPP, ("vnode_pager: FS getpages not implemented\n")); VFS_UNLOCK_GIANT(vfslocked); VM_OBJECT_LOCK(object); return rtval; } /* * This is now called from local media FS's to operate against their * own vnodes if they fail to implement VOP_GETPAGES. */ int vnode_pager_generic_getpages(vp, m, bytecount, reqpage) struct vnode *vp; vm_page_t *m; int bytecount; int reqpage; { vm_object_t object; vm_offset_t kva; off_t foff, tfoff, nextoff; int i, j, size, bsize, first; daddr_t firstaddr, reqblock; struct bufobj *bo; int runpg; int runend; struct buf *bp; int count; int error; object = vp->v_object; count = bytecount / PAGE_SIZE; KASSERT(vp->v_type != VCHR && vp->v_type != VBLK, ("vnode_pager_generic_getpages does not support devices")); if (vp->v_iflag & VI_DOOMED) return VM_PAGER_BAD; bsize = vp->v_mount->mnt_stat.f_iosize; /* get the UNDERLYING device for the file with VOP_BMAP() */ /* * originally, we did not check for an error return value -- assuming * an fs always has a bmap entry point -- that assumption is wrong!!! */ foff = IDX_TO_OFF(m[reqpage]->pindex); /* * if we can't bmap, use old VOP code */ error = VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL); if (error == EOPNOTSUPP) { VM_OBJECT_LOCK(object); for (i = 0; i < count; i++) if (i != reqpage) { vm_page_lock(m[i]); vm_page_free(m[i]); vm_page_unlock(m[i]); } PCPU_INC(cnt.v_vnodein); PCPU_INC(cnt.v_vnodepgsin); error = vnode_pager_input_old(object, m[reqpage]); VM_OBJECT_UNLOCK(object); return (error); } else if (error != 0) { VM_OBJECT_LOCK(object); for (i = 0; i < count; i++) if (i != reqpage) { vm_page_lock(m[i]); vm_page_free(m[i]); vm_page_unlock(m[i]); } VM_OBJECT_UNLOCK(object); return (VM_PAGER_ERROR); /* * if the blocksize is smaller than a page size, then use * special small filesystem code. NFS sometimes has a small * blocksize, but it can handle large reads itself. */ } else if ((PAGE_SIZE / bsize) > 1 && (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) { VM_OBJECT_LOCK(object); for (i = 0; i < count; i++) if (i != reqpage) { vm_page_lock(m[i]); vm_page_free(m[i]); vm_page_unlock(m[i]); } VM_OBJECT_UNLOCK(object); PCPU_INC(cnt.v_vnodein); PCPU_INC(cnt.v_vnodepgsin); return vnode_pager_input_smlfs(object, m[reqpage]); } /* * If we have a completely valid page available to us, we can * clean up and return. Otherwise we have to re-read the * media. */ VM_OBJECT_LOCK(object); if (m[reqpage]->valid == VM_PAGE_BITS_ALL) { for (i = 0; i < count; i++) if (i != reqpage) { vm_page_lock(m[i]); vm_page_free(m[i]); vm_page_unlock(m[i]); } VM_OBJECT_UNLOCK(object); return VM_PAGER_OK; } else if (reqblock == -1) { pmap_zero_page(m[reqpage]); KASSERT(m[reqpage]->dirty == 0, ("vnode_pager_generic_getpages: page %p is dirty", m)); m[reqpage]->valid = VM_PAGE_BITS_ALL; for (i = 0; i < count; i++) if (i != reqpage) { vm_page_lock(m[i]); vm_page_free(m[i]); vm_page_unlock(m[i]); } VM_OBJECT_UNLOCK(object); return (VM_PAGER_OK); } m[reqpage]->valid = 0; VM_OBJECT_UNLOCK(object); /* * here on direct device I/O */ firstaddr = -1; /* * calculate the run that includes the required page */ for (first = 0, i = 0; i < count; i = runend) { if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr, &runpg) != 0) { VM_OBJECT_LOCK(object); for (; i < count; i++) if (i != reqpage) { vm_page_lock(m[i]); vm_page_free(m[i]); vm_page_unlock(m[i]); } VM_OBJECT_UNLOCK(object); return (VM_PAGER_ERROR); } if (firstaddr == -1) { VM_OBJECT_LOCK(object); if (i == reqpage && foff < object->un_pager.vnp.vnp_size) { panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx", (intmax_t)firstaddr, (uintmax_t)(foff >> 32), (uintmax_t)foff, (uintmax_t) (object->un_pager.vnp.vnp_size >> 32), (uintmax_t)object->un_pager.vnp.vnp_size); } vm_page_lock(m[i]); vm_page_free(m[i]); vm_page_unlock(m[i]); VM_OBJECT_UNLOCK(object); runend = i + 1; first = runend; continue; } runend = i + runpg; if (runend <= reqpage) { VM_OBJECT_LOCK(object); for (j = i; j < runend; j++) { vm_page_lock(m[j]); vm_page_free(m[j]); vm_page_unlock(m[j]); } VM_OBJECT_UNLOCK(object); } else { if (runpg < (count - first)) { VM_OBJECT_LOCK(object); for (i = first + runpg; i < count; i++) { vm_page_lock(m[i]); vm_page_free(m[i]); vm_page_unlock(m[i]); } VM_OBJECT_UNLOCK(object); count = first + runpg; } break; } first = runend; } /* * the first and last page have been calculated now, move input pages * to be zero based... */ if (first != 0) { m += first; count -= first; reqpage -= first; } /* * calculate the file virtual address for the transfer */ foff = IDX_TO_OFF(m[0]->pindex); /* * calculate the size of the transfer */ size = count * PAGE_SIZE; KASSERT(count > 0, ("zero count")); if ((foff + size) > object->un_pager.vnp.vnp_size) size = object->un_pager.vnp.vnp_size - foff; KASSERT(size > 0, ("zero size")); /* * round up physical size for real devices. */ if (1) { int secmask = bo->bo_bsize - 1; KASSERT(secmask < PAGE_SIZE && secmask > 0, ("vnode_pager_generic_getpages: sector size %d too large", secmask + 1)); size = (size + secmask) & ~secmask; } bp = getpbuf(&vnode_pbuf_freecnt); - kva = (vm_offset_t) bp->b_data; + kva = (vm_offset_t)bp->b_data; /* * and map the pages to be read into the kva */ pmap_qenter(kva, m, count); /* build a minimal buffer header */ bp->b_iocmd = BIO_READ; bp->b_iodone = bdone; KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred")); KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred")); bp->b_rcred = crhold(curthread->td_ucred); bp->b_wcred = crhold(curthread->td_ucred); bp->b_blkno = firstaddr; pbgetbo(bo, bp); bp->b_vp = vp; bp->b_bcount = size; bp->b_bufsize = size; bp->b_runningbufspace = bp->b_bufsize; atomic_add_long(&runningbufspace, bp->b_runningbufspace); PCPU_INC(cnt.v_vnodein); PCPU_ADD(cnt.v_vnodepgsin, count); /* do the input */ bp->b_iooffset = dbtob(bp->b_blkno); bstrategy(bp); bwait(bp, PVM, "vnread"); if ((bp->b_ioflags & BIO_ERROR) != 0) error = EIO; if (!error) { if (size != count * PAGE_SIZE) bzero((caddr_t) kva + size, PAGE_SIZE * count - size); } pmap_qremove(kva, count); /* * free the buffer header back to the swap buffer pool */ bp->b_vp = NULL; pbrelbo(bp); relpbuf(bp, &vnode_pbuf_freecnt); VM_OBJECT_LOCK(object); for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) { vm_page_t mt; nextoff = tfoff + PAGE_SIZE; mt = m[i]; if (nextoff <= object->un_pager.vnp.vnp_size) { /* * Read filled up entire page. */ mt->valid = VM_PAGE_BITS_ALL; KASSERT(mt->dirty == 0, ("vnode_pager_generic_getpages: page %p is dirty", mt)); KASSERT(!pmap_page_is_mapped(mt), ("vnode_pager_generic_getpages: page %p is mapped", mt)); } else { /* * Read did not fill up entire page. * * Currently we do not set the entire page valid, * we just try to clear the piece that we couldn't * read. */ vm_page_set_valid(mt, 0, object->un_pager.vnp.vnp_size - tfoff); KASSERT((mt->dirty & vm_page_bits(0, object->un_pager.vnp.vnp_size - tfoff)) == 0, ("vnode_pager_generic_getpages: page %p is dirty", mt)); } if (i != reqpage) vm_page_readahead_finish(mt); } VM_OBJECT_UNLOCK(object); if (error) { printf("vnode_pager_getpages: I/O read error\n"); } return (error ? VM_PAGER_ERROR : VM_PAGER_OK); } /* * EOPNOTSUPP is no longer legal. For local media VFS's that do not * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to * vnode_pager_generic_putpages() to implement the previous behaviour. * * All other FS's should use the bypass to get to the local media * backing vp's VOP_PUTPAGES. */ static void vnode_pager_putpages(object, m, count, sync, rtvals) vm_object_t object; vm_page_t *m; int count; boolean_t sync; int *rtvals; { int rtval; struct vnode *vp; int bytes = count * PAGE_SIZE; /* * Force synchronous operation if we are extremely low on memory * to prevent a low-memory deadlock. VOP operations often need to * allocate more memory to initiate the I/O ( i.e. do a BMAP * operation ). The swapper handles the case by limiting the amount * of asynchronous I/O, but that sort of solution doesn't scale well * for the vnode pager without a lot of work. * * Also, the backing vnode's iodone routine may not wake the pageout * daemon up. This should be probably be addressed XXX. */ if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min) sync |= OBJPC_SYNC; /* * Call device-specific putpages function */ vp = object->handle; VM_OBJECT_UNLOCK(object); rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0); KASSERT(rtval != EOPNOTSUPP, ("vnode_pager: stale FS putpages\n")); VM_OBJECT_LOCK(object); } /* * This is now called from local media FS's to operate against their * own vnodes if they fail to implement VOP_PUTPAGES. * * This is typically called indirectly via the pageout daemon and * clustering has already typically occured, so in general we ask the * underlying filesystem to write the data out asynchronously rather * then delayed. */ int vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount, int flags, int *rtvals) { int i; vm_object_t object; vm_page_t m; int count; int maxsize, ncount; vm_ooffset_t poffset; struct uio auio; struct iovec aiov; int error; int ioflags; int ppscheck = 0; static struct timeval lastfail; static int curfail; object = vp->v_object; count = bytecount / PAGE_SIZE; for (i = 0; i < count; i++) rtvals[i] = VM_PAGER_ERROR; if ((int64_t)ma[0]->pindex < 0) { printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n", (long)ma[0]->pindex, (u_long)ma[0]->dirty); rtvals[0] = VM_PAGER_BAD; return VM_PAGER_BAD; } maxsize = count * PAGE_SIZE; ncount = count; poffset = IDX_TO_OFF(ma[0]->pindex); /* * If the page-aligned write is larger then the actual file we * have to invalidate pages occuring beyond the file EOF. However, * there is an edge case where a file may not be page-aligned where * the last page is partially invalid. In this case the filesystem * may not properly clear the dirty bits for the entire page (which * could be VM_PAGE_BITS_ALL due to the page having been mmap()d). * With the page locked we are free to fix-up the dirty bits here. * * We do not under any circumstances truncate the valid bits, as * this will screw up bogus page replacement. */ VM_OBJECT_LOCK(object); if (maxsize + poffset > object->un_pager.vnp.vnp_size) { if (object->un_pager.vnp.vnp_size > poffset) { int pgoff; maxsize = object->un_pager.vnp.vnp_size - poffset; ncount = btoc(maxsize); if ((pgoff = (int)maxsize & PAGE_MASK) != 0) { /* * If the object is locked and the following * conditions hold, then the page's dirty * field cannot be concurrently changed by a * pmap operation. */ m = ma[ncount - 1]; KASSERT(m->busy > 0, ("vnode_pager_generic_putpages: page %p is not busy", m)); KASSERT(!pmap_page_is_write_mapped(m), ("vnode_pager_generic_putpages: page %p is not read-only", m)); vm_page_clear_dirty(m, pgoff, PAGE_SIZE - pgoff); } } else { maxsize = 0; ncount = 0; } if (ncount < count) { for (i = ncount; i < count; i++) { rtvals[i] = VM_PAGER_BAD; } } } VM_OBJECT_UNLOCK(object); /* * pageouts are already clustered, use IO_ASYNC t o force a bawrite() * rather then a bdwrite() to prevent paging I/O from saturating * the buffer cache. Dummy-up the sequential heuristic to cause * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set, * the system decides how to cluster. */ ioflags = IO_VMIO; if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) ioflags |= IO_SYNC; else if ((flags & VM_PAGER_CLUSTER_OK) == 0) ioflags |= IO_ASYNC; ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0; ioflags |= IO_SEQMAX << IO_SEQSHIFT; aiov.iov_base = (caddr_t) 0; aiov.iov_len = maxsize; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = poffset; auio.uio_segflg = UIO_NOCOPY; auio.uio_rw = UIO_WRITE; auio.uio_resid = maxsize; auio.uio_td = (struct thread *) 0; error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred); PCPU_INC(cnt.v_vnodeout); PCPU_ADD(cnt.v_vnodepgsout, ncount); if (error) { if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1))) printf("vnode_pager_putpages: I/O error %d\n", error); } if (auio.uio_resid) { if (ppscheck || ppsratecheck(&lastfail, &curfail, 1)) printf("vnode_pager_putpages: residual I/O %zd at %lu\n", auio.uio_resid, (u_long)ma[0]->pindex); } for (i = 0; i < ncount; i++) { rtvals[i] = VM_PAGER_OK; } return rtvals[0]; } void vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written) { vm_object_t obj; int i, pos; if (written == 0) return; obj = ma[0]->object; VM_OBJECT_LOCK(obj); for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) { if (pos < trunc_page(written)) { rtvals[i] = VM_PAGER_OK; vm_page_undirty(ma[i]); } else { /* Partially written page. */ rtvals[i] = VM_PAGER_AGAIN; vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK); } } VM_OBJECT_UNLOCK(obj); } void vnode_pager_update_writecount(vm_object_t object, vm_offset_t start, vm_offset_t end) { struct vnode *vp; vm_ooffset_t old_wm; VM_OBJECT_LOCK(object); if (object->type != OBJT_VNODE) { VM_OBJECT_UNLOCK(object); return; } old_wm = object->un_pager.vnp.writemappings; object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start; vp = object->handle; if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) { ASSERT_VOP_ELOCKED(vp, "v_writecount inc"); VOP_ADD_WRITECOUNT(vp, 1); } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) { ASSERT_VOP_ELOCKED(vp, "v_writecount dec"); VOP_ADD_WRITECOUNT(vp, -1); } VM_OBJECT_UNLOCK(object); } void vnode_pager_release_writecount(vm_object_t object, vm_offset_t start, vm_offset_t end) { struct vnode *vp; struct mount *mp; vm_offset_t inc; int vfslocked; VM_OBJECT_LOCK(object); /* * First, recheck the object type to account for the race when * the vnode is reclaimed. */ if (object->type != OBJT_VNODE) { VM_OBJECT_UNLOCK(object); return; } /* * Optimize for the case when writemappings is not going to * zero. */ inc = end - start; if (object->un_pager.vnp.writemappings != inc) { object->un_pager.vnp.writemappings -= inc; VM_OBJECT_UNLOCK(object); return; } vp = object->handle; vhold(vp); VM_OBJECT_UNLOCK(object); vfslocked = VFS_LOCK_GIANT(vp->v_mount); mp = NULL; vn_start_write(vp, &mp, V_WAIT); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); /* * Decrement the object's writemappings, by swapping the start * and end arguments for vnode_pager_update_writecount(). If * there was not a race with vnode reclaimation, then the * vnode's v_writecount is decremented. */ vnode_pager_update_writecount(object, end, start); VOP_UNLOCK(vp, 0); vdrop(vp); if (mp != NULL) vn_finished_write(mp); VFS_UNLOCK_GIANT(vfslocked); } Index: stable/9/sys =================================================================== --- stable/9/sys (revision 250946) +++ stable/9/sys (revision 250947) Property changes on: stable/9/sys ___________________________________________________________________ Modified: svn:mergeinfo ## -0,0 +0,1 ## Merged /head/sys:r248283