diff --git a/sys/dev/md/md.c b/sys/dev/md/md.c index f44a2e940faa..243ac2be72d9 100644 --- a/sys/dev/md/md.c +++ b/sys/dev/md/md.c @@ -1,2173 +1,2175 @@ /*- * SPDX-License-Identifier: (Beerware AND BSD-3-Clause) * * ---------------------------------------------------------------------------- * "THE BEER-WARE LICENSE" (Revision 42): * wrote this file. As long as you retain this notice you * can do whatever you want with this stuff. If we meet some day, and you think * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp * ---------------------------------------------------------------------------- * * $FreeBSD$ * */ /*- * The following functions are based on the vn(4) driver: mdstart_swap(), * mdstart_vnode(), mdcreate_swap(), mdcreate_vnode() and mddestroy(), * and as such under the following copyright: * * Copyright (c) 1988 University of Utah. * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * Copyright (c) 2013 The FreeBSD Foundation * All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department. * * Portions of this software were developed by Konstantin Belousov * under sponsorship from the FreeBSD Foundation. * * 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. 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: Utah Hdr: vn.c 1.13 94/04/02 * * from: @(#)vn.c 8.6 (Berkeley) 4/1/94 * From: src/sys/dev/vn/vn.c,v 1.122 2000/12/16 16:06:03 */ #include "opt_rootdevname.h" #include "opt_geom.h" #include "opt_md.h" #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 #include #include #include #include #include #include #include #include #define MD_MODVER 1 #define MD_SHUTDOWN 0x10000 /* Tell worker thread to terminate. */ #define MD_EXITING 0x20000 /* Worker thread is exiting. */ #define MD_PROVIDERGONE 0x40000 /* Safe to free the softc */ #ifndef MD_NSECT #define MD_NSECT (10000 * 2) #endif struct md_req { unsigned md_unit; /* unit number */ enum md_types md_type; /* type of disk */ off_t md_mediasize; /* size of disk in bytes */ unsigned md_sectorsize; /* sectorsize */ unsigned md_options; /* options */ int md_fwheads; /* firmware heads */ int md_fwsectors; /* firmware sectors */ char *md_file; /* pathname of file to mount */ enum uio_seg md_file_seg; /* location of md_file */ char *md_label; /* label of the device (userspace) */ int *md_units; /* pointer to units array (kernel) */ size_t md_units_nitems; /* items in md_units array */ }; #ifdef COMPAT_FREEBSD32 struct md_ioctl32 { unsigned md_version; unsigned md_unit; enum md_types md_type; uint32_t md_file; off_t md_mediasize; unsigned md_sectorsize; unsigned md_options; uint64_t md_base; int md_fwheads; int md_fwsectors; uint32_t md_label; int md_pad[MDNPAD]; } __attribute__((__packed__)); CTASSERT((sizeof(struct md_ioctl32)) == 436); #define MDIOCATTACH_32 _IOC_NEWTYPE(MDIOCATTACH, struct md_ioctl32) #define MDIOCDETACH_32 _IOC_NEWTYPE(MDIOCDETACH, struct md_ioctl32) #define MDIOCQUERY_32 _IOC_NEWTYPE(MDIOCQUERY, struct md_ioctl32) #define MDIOCRESIZE_32 _IOC_NEWTYPE(MDIOCRESIZE, struct md_ioctl32) #endif /* COMPAT_FREEBSD32 */ static MALLOC_DEFINE(M_MD, "md_disk", "Memory Disk"); static MALLOC_DEFINE(M_MDSECT, "md_sectors", "Memory Disk Sectors"); static int md_debug; SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0, "Enable md(4) debug messages"); static int md_malloc_wait; SYSCTL_INT(_vm, OID_AUTO, md_malloc_wait, CTLFLAG_RW, &md_malloc_wait, 0, "Allow malloc to wait for memory allocations"); #if defined(MD_ROOT) && !defined(MD_ROOT_FSTYPE) #define MD_ROOT_FSTYPE "ufs" #endif #if defined(MD_ROOT) /* * Preloaded image gets put here. */ #if defined(MD_ROOT_SIZE) /* * We put the mfs_root symbol into the oldmfs section of the kernel object file. * Applications that patch the object with the image can determine * the size looking at the oldmfs section size within the kernel. */ u_char mfs_root[MD_ROOT_SIZE*1024] __attribute__ ((section ("oldmfs"))); const int mfs_root_size = sizeof(mfs_root); #elif defined(MD_ROOT_MEM) /* MD region already mapped in the memory */ u_char *mfs_root; int mfs_root_size; #else extern volatile u_char __weak_symbol mfs_root; extern volatile u_char __weak_symbol mfs_root_end; #define mfs_root_size ((uintptr_t)(&mfs_root_end - &mfs_root)) #endif #endif static g_init_t g_md_init; static g_fini_t g_md_fini; static g_start_t g_md_start; static g_access_t g_md_access; static void g_md_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp); static g_provgone_t g_md_providergone; static struct cdev *status_dev = NULL; static struct sx md_sx; static struct unrhdr *md_uh; static d_ioctl_t mdctlioctl; static struct cdevsw mdctl_cdevsw = { .d_version = D_VERSION, .d_ioctl = mdctlioctl, .d_name = MD_NAME, }; struct g_class g_md_class = { .name = "MD", .version = G_VERSION, .init = g_md_init, .fini = g_md_fini, .start = g_md_start, .access = g_md_access, .dumpconf = g_md_dumpconf, .providergone = g_md_providergone, }; DECLARE_GEOM_CLASS(g_md_class, g_md); MODULE_VERSION(geom_md, 0); static LIST_HEAD(, md_s) md_softc_list = LIST_HEAD_INITIALIZER(md_softc_list); #define NINDIR (PAGE_SIZE / sizeof(uintptr_t)) #define NMASK (NINDIR-1) static int nshift; static uma_zone_t md_pbuf_zone; struct indir { uintptr_t *array; u_int total; u_int used; u_int shift; }; struct md_s { int unit; LIST_ENTRY(md_s) list; struct bio_queue_head bio_queue; struct mtx queue_mtx; struct cdev *dev; enum md_types type; off_t mediasize; unsigned sectorsize; unsigned opencount; unsigned fwheads; unsigned fwsectors; char ident[32]; unsigned flags; char name[20]; struct proc *procp; struct g_geom *gp; struct g_provider *pp; int (*start)(struct md_s *sc, struct bio *bp); struct devstat *devstat; /* MD_MALLOC related fields */ struct indir *indir; uma_zone_t uma; /* MD_PRELOAD related fields */ u_char *pl_ptr; size_t pl_len; /* MD_VNODE related fields */ struct vnode *vnode; char file[PATH_MAX]; char label[PATH_MAX]; struct ucred *cred; /* MD_SWAP related fields */ vm_object_t object; }; static struct indir * new_indir(u_int shift) { struct indir *ip; ip = malloc(sizeof *ip, M_MD, (md_malloc_wait ? M_WAITOK : M_NOWAIT) | M_ZERO); if (ip == NULL) return (NULL); ip->array = malloc(sizeof(uintptr_t) * NINDIR, M_MDSECT, (md_malloc_wait ? M_WAITOK : M_NOWAIT) | M_ZERO); if (ip->array == NULL) { free(ip, M_MD); return (NULL); } ip->total = NINDIR; ip->shift = shift; return (ip); } static void del_indir(struct indir *ip) { free(ip->array, M_MDSECT); free(ip, M_MD); } static void destroy_indir(struct md_s *sc, struct indir *ip) { int i; for (i = 0; i < NINDIR; i++) { if (!ip->array[i]) continue; if (ip->shift) destroy_indir(sc, (struct indir*)(ip->array[i])); else if (ip->array[i] > 255) uma_zfree(sc->uma, (void *)(ip->array[i])); } del_indir(ip); } /* * This function does the math and allocates the top level "indir" structure * for a device of "size" sectors. */ static struct indir * dimension(off_t size) { off_t rcnt; struct indir *ip; int layer; rcnt = size; layer = 0; while (rcnt > NINDIR) { rcnt /= NINDIR; layer++; } /* * XXX: the top layer is probably not fully populated, so we allocate * too much space for ip->array in here. */ ip = malloc(sizeof *ip, M_MD, M_WAITOK | M_ZERO); ip->array = malloc(sizeof(uintptr_t) * NINDIR, M_MDSECT, M_WAITOK | M_ZERO); ip->total = NINDIR; ip->shift = layer * nshift; return (ip); } /* * Read a given sector */ static uintptr_t s_read(struct indir *ip, off_t offset) { struct indir *cip; int idx; uintptr_t up; if (md_debug > 1) printf("s_read(%jd)\n", (intmax_t)offset); up = 0; for (cip = ip; cip != NULL;) { if (cip->shift) { idx = (offset >> cip->shift) & NMASK; up = cip->array[idx]; cip = (struct indir *)up; continue; } idx = offset & NMASK; return (cip->array[idx]); } return (0); } /* * Write a given sector, prune the tree if the value is 0 */ static int s_write(struct indir *ip, off_t offset, uintptr_t ptr) { struct indir *cip, *lip[10]; int idx, li; uintptr_t up; if (md_debug > 1) printf("s_write(%jd, %p)\n", (intmax_t)offset, (void *)ptr); up = 0; li = 0; cip = ip; for (;;) { lip[li++] = cip; if (cip->shift) { idx = (offset >> cip->shift) & NMASK; up = cip->array[idx]; if (up != 0) { cip = (struct indir *)up; continue; } /* Allocate branch */ cip->array[idx] = (uintptr_t)new_indir(cip->shift - nshift); if (cip->array[idx] == 0) return (ENOSPC); cip->used++; up = cip->array[idx]; cip = (struct indir *)up; continue; } /* leafnode */ idx = offset & NMASK; up = cip->array[idx]; if (up != 0) cip->used--; cip->array[idx] = ptr; if (ptr != 0) cip->used++; break; } if (cip->used != 0 || li == 1) return (0); li--; while (cip->used == 0 && cip != ip) { li--; idx = (offset >> lip[li]->shift) & NMASK; up = lip[li]->array[idx]; KASSERT(up == (uintptr_t)cip, ("md screwed up")); del_indir(cip); lip[li]->array[idx] = 0; lip[li]->used--; cip = lip[li]; } return (0); } static int g_md_access(struct g_provider *pp, int r, int w, int e) { struct md_s *sc; sc = pp->geom->softc; if (sc == NULL) { if (r <= 0 && w <= 0 && e <= 0) return (0); return (ENXIO); } r += pp->acr; w += pp->acw; e += pp->ace; if ((sc->flags & MD_READONLY) != 0 && w > 0) return (EROFS); if ((pp->acr + pp->acw + pp->ace) == 0 && (r + w + e) > 0) { sc->opencount = 1; } else if ((pp->acr + pp->acw + pp->ace) > 0 && (r + w + e) == 0) { sc->opencount = 0; } return (0); } static void g_md_start(struct bio *bp) { struct md_s *sc; sc = bp->bio_to->geom->softc; if ((bp->bio_cmd == BIO_READ) || (bp->bio_cmd == BIO_WRITE)) { devstat_start_transaction_bio(sc->devstat, bp); } mtx_lock(&sc->queue_mtx); bioq_disksort(&sc->bio_queue, bp); wakeup(sc); mtx_unlock(&sc->queue_mtx); } #define MD_MALLOC_MOVE_ZERO 1 #define MD_MALLOC_MOVE_FILL 2 #define MD_MALLOC_MOVE_READ 3 #define MD_MALLOC_MOVE_WRITE 4 #define MD_MALLOC_MOVE_CMP 5 static int md_malloc_move_ma(vm_page_t **mp, int *ma_offs, unsigned sectorsize, void *ptr, u_char fill, int op) { struct sf_buf *sf; vm_page_t m, *mp1; char *p, first; off_t *uc; unsigned n; int error, i, ma_offs1, sz, first_read; m = NULL; error = 0; sf = NULL; /* if (op == MD_MALLOC_MOVE_CMP) { gcc */ first = 0; first_read = 0; uc = ptr; mp1 = *mp; ma_offs1 = *ma_offs; /* } */ sched_pin(); for (n = sectorsize; n != 0; n -= sz) { sz = imin(PAGE_SIZE - *ma_offs, n); if (m != **mp) { if (sf != NULL) sf_buf_free(sf); m = **mp; sf = sf_buf_alloc(m, SFB_CPUPRIVATE | (md_malloc_wait ? 0 : SFB_NOWAIT)); if (sf == NULL) { error = ENOMEM; break; } } p = (char *)sf_buf_kva(sf) + *ma_offs; switch (op) { case MD_MALLOC_MOVE_ZERO: bzero(p, sz); break; case MD_MALLOC_MOVE_FILL: memset(p, fill, sz); break; case MD_MALLOC_MOVE_READ: bcopy(ptr, p, sz); cpu_flush_dcache(p, sz); break; case MD_MALLOC_MOVE_WRITE: bcopy(p, ptr, sz); break; case MD_MALLOC_MOVE_CMP: for (i = 0; i < sz; i++, p++) { if (!first_read) { *uc = (u_char)*p; first = *p; first_read = 1; } else if (*p != first) { error = EDOOFUS; break; } } break; default: KASSERT(0, ("md_malloc_move_ma unknown op %d\n", op)); break; } if (error != 0) break; *ma_offs += sz; *ma_offs %= PAGE_SIZE; if (*ma_offs == 0) (*mp)++; ptr = (char *)ptr + sz; } if (sf != NULL) sf_buf_free(sf); sched_unpin(); if (op == MD_MALLOC_MOVE_CMP && error != 0) { *mp = mp1; *ma_offs = ma_offs1; } return (error); } static int md_malloc_move_vlist(bus_dma_segment_t **pvlist, int *pma_offs, unsigned len, void *ptr, u_char fill, int op) { bus_dma_segment_t *vlist; uint8_t *p, *end, first; off_t *uc; int ma_offs, seg_len; vlist = *pvlist; ma_offs = *pma_offs; uc = ptr; for (; len != 0; len -= seg_len) { seg_len = imin(vlist->ds_len - ma_offs, len); p = (uint8_t *)(uintptr_t)vlist->ds_addr + ma_offs; switch (op) { case MD_MALLOC_MOVE_ZERO: bzero(p, seg_len); break; case MD_MALLOC_MOVE_FILL: memset(p, fill, seg_len); break; case MD_MALLOC_MOVE_READ: bcopy(ptr, p, seg_len); cpu_flush_dcache(p, seg_len); break; case MD_MALLOC_MOVE_WRITE: bcopy(p, ptr, seg_len); break; case MD_MALLOC_MOVE_CMP: end = p + seg_len; first = *uc = *p; /* Confirm all following bytes match the first */ while (++p < end) { if (*p != first) return (EDOOFUS); } break; default: KASSERT(0, ("md_malloc_move_vlist unknown op %d\n", op)); break; } ma_offs += seg_len; if (ma_offs == vlist->ds_len) { ma_offs = 0; vlist++; } ptr = (uint8_t *)ptr + seg_len; } *pvlist = vlist; *pma_offs = ma_offs; return (0); } static int mdstart_malloc(struct md_s *sc, struct bio *bp) { u_char *dst; vm_page_t *m; bus_dma_segment_t *vlist; int i, error, error1, ma_offs, notmapped; off_t secno, nsec, uc; uintptr_t sp, osp; switch (bp->bio_cmd) { case BIO_READ: case BIO_WRITE: case BIO_DELETE: break; case BIO_FLUSH: return (0); default: return (EOPNOTSUPP); } notmapped = (bp->bio_flags & BIO_UNMAPPED) != 0; vlist = (bp->bio_flags & BIO_VLIST) != 0 ? (bus_dma_segment_t *)bp->bio_data : NULL; if (notmapped) { m = bp->bio_ma; ma_offs = bp->bio_ma_offset; dst = NULL; KASSERT(vlist == NULL, ("vlists cannot be unmapped")); } else if (vlist != NULL) { ma_offs = bp->bio_ma_offset; dst = NULL; } else { dst = bp->bio_data; } nsec = bp->bio_length / sc->sectorsize; secno = bp->bio_offset / sc->sectorsize; error = 0; while (nsec--) { osp = s_read(sc->indir, secno); if (bp->bio_cmd == BIO_DELETE) { if (osp != 0) error = s_write(sc->indir, secno, 0); } else if (bp->bio_cmd == BIO_READ) { if (osp == 0) { if (notmapped) { error = md_malloc_move_ma(&m, &ma_offs, sc->sectorsize, NULL, 0, MD_MALLOC_MOVE_ZERO); } else if (vlist != NULL) { error = md_malloc_move_vlist(&vlist, &ma_offs, sc->sectorsize, NULL, 0, MD_MALLOC_MOVE_ZERO); } else bzero(dst, sc->sectorsize); } else if (osp <= 255) { if (notmapped) { error = md_malloc_move_ma(&m, &ma_offs, sc->sectorsize, NULL, osp, MD_MALLOC_MOVE_FILL); } else if (vlist != NULL) { error = md_malloc_move_vlist(&vlist, &ma_offs, sc->sectorsize, NULL, osp, MD_MALLOC_MOVE_FILL); } else memset(dst, osp, sc->sectorsize); } else { if (notmapped) { error = md_malloc_move_ma(&m, &ma_offs, sc->sectorsize, (void *)osp, 0, MD_MALLOC_MOVE_READ); } else if (vlist != NULL) { error = md_malloc_move_vlist(&vlist, &ma_offs, sc->sectorsize, (void *)osp, 0, MD_MALLOC_MOVE_READ); } else { bcopy((void *)osp, dst, sc->sectorsize); cpu_flush_dcache(dst, sc->sectorsize); } } osp = 0; } else if (bp->bio_cmd == BIO_WRITE) { if (sc->flags & MD_COMPRESS) { if (notmapped) { error1 = md_malloc_move_ma(&m, &ma_offs, sc->sectorsize, &uc, 0, MD_MALLOC_MOVE_CMP); i = error1 == 0 ? sc->sectorsize : 0; } else if (vlist != NULL) { error1 = md_malloc_move_vlist(&vlist, &ma_offs, sc->sectorsize, &uc, 0, MD_MALLOC_MOVE_CMP); i = error1 == 0 ? sc->sectorsize : 0; } else { uc = dst[0]; for (i = 1; i < sc->sectorsize; i++) { if (dst[i] != uc) break; } } } else { i = 0; uc = 0; } if (i == sc->sectorsize) { if (osp != uc) error = s_write(sc->indir, secno, uc); } else { if (osp <= 255) { sp = (uintptr_t)uma_zalloc(sc->uma, md_malloc_wait ? M_WAITOK : M_NOWAIT); if (sp == 0) { error = ENOSPC; break; } if (notmapped) { error = md_malloc_move_ma(&m, &ma_offs, sc->sectorsize, (void *)sp, 0, MD_MALLOC_MOVE_WRITE); } else if (vlist != NULL) { error = md_malloc_move_vlist( &vlist, &ma_offs, sc->sectorsize, (void *)sp, 0, MD_MALLOC_MOVE_WRITE); } else { bcopy(dst, (void *)sp, sc->sectorsize); } error = s_write(sc->indir, secno, sp); } else { if (notmapped) { error = md_malloc_move_ma(&m, &ma_offs, sc->sectorsize, (void *)osp, 0, MD_MALLOC_MOVE_WRITE); } else if (vlist != NULL) { error = md_malloc_move_vlist( &vlist, &ma_offs, sc->sectorsize, (void *)osp, 0, MD_MALLOC_MOVE_WRITE); } else { bcopy(dst, (void *)osp, sc->sectorsize); } osp = 0; } } } else { error = EOPNOTSUPP; } if (osp > 255) uma_zfree(sc->uma, (void*)osp); if (error != 0) break; secno++; if (!notmapped && vlist == NULL) dst += sc->sectorsize; } bp->bio_resid = 0; return (error); } static void mdcopyto_vlist(void *src, bus_dma_segment_t *vlist, off_t offset, off_t len) { off_t seg_len; while (offset >= vlist->ds_len) { offset -= vlist->ds_len; vlist++; } while (len != 0) { seg_len = omin(len, vlist->ds_len - offset); bcopy(src, (void *)(uintptr_t)(vlist->ds_addr + offset), seg_len); offset = 0; src = (uint8_t *)src + seg_len; len -= seg_len; vlist++; } } static void mdcopyfrom_vlist(bus_dma_segment_t *vlist, off_t offset, void *dst, off_t len) { off_t seg_len; while (offset >= vlist->ds_len) { offset -= vlist->ds_len; vlist++; } while (len != 0) { seg_len = omin(len, vlist->ds_len - offset); bcopy((void *)(uintptr_t)(vlist->ds_addr + offset), dst, seg_len); offset = 0; dst = (uint8_t *)dst + seg_len; len -= seg_len; vlist++; } } static int mdstart_preload(struct md_s *sc, struct bio *bp) { uint8_t *p; p = sc->pl_ptr + bp->bio_offset; switch (bp->bio_cmd) { case BIO_READ: if ((bp->bio_flags & BIO_VLIST) != 0) { mdcopyto_vlist(p, (bus_dma_segment_t *)bp->bio_data, bp->bio_ma_offset, bp->bio_length); } else { bcopy(p, bp->bio_data, bp->bio_length); } cpu_flush_dcache(bp->bio_data, bp->bio_length); break; case BIO_WRITE: if ((bp->bio_flags & BIO_VLIST) != 0) { mdcopyfrom_vlist((bus_dma_segment_t *)bp->bio_data, bp->bio_ma_offset, p, bp->bio_length); } else { bcopy(bp->bio_data, p, bp->bio_length); } break; } bp->bio_resid = 0; return (0); } static int mdstart_vnode(struct md_s *sc, struct bio *bp) { int error; struct uio auio; struct iovec aiov; struct iovec *piov; struct mount *mp; struct vnode *vp; struct buf *pb; bus_dma_segment_t *vlist; struct thread *td; off_t iolen, iostart, len, zerosize; int ma_offs, npages; switch (bp->bio_cmd) { case BIO_READ: auio.uio_rw = UIO_READ; break; case BIO_WRITE: case BIO_DELETE: auio.uio_rw = UIO_WRITE; break; case BIO_FLUSH: break; default: return (EOPNOTSUPP); } td = curthread; vp = sc->vnode; pb = NULL; piov = NULL; ma_offs = bp->bio_ma_offset; len = bp->bio_length; /* * VNODE I/O * * If an error occurs, we set BIO_ERROR but we do not set * B_INVAL because (for a write anyway), the buffer is * still valid. */ if (bp->bio_cmd == BIO_FLUSH) { - (void) vn_start_write(vp, &mp, V_WAIT); - vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); - error = VOP_FSYNC(vp, MNT_WAIT, td); - VOP_UNLOCK(vp); - vn_finished_write(mp); + do { + (void) vn_start_write(vp, &mp, V_WAIT); + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); + error = VOP_FSYNC(vp, MNT_WAIT, td); + VOP_UNLOCK(vp); + vn_finished_write(mp); + } while (error == ERELOOKUP); return (error); } auio.uio_offset = (vm_ooffset_t)bp->bio_offset; auio.uio_resid = bp->bio_length; auio.uio_segflg = UIO_SYSSPACE; auio.uio_td = td; if (bp->bio_cmd == BIO_DELETE) { /* * Emulate BIO_DELETE by writing zeros. */ zerosize = ZERO_REGION_SIZE - (ZERO_REGION_SIZE % sc->sectorsize); auio.uio_iovcnt = howmany(bp->bio_length, zerosize); piov = malloc(sizeof(*piov) * auio.uio_iovcnt, M_MD, M_WAITOK); auio.uio_iov = piov; while (len > 0) { piov->iov_base = __DECONST(void *, zero_region); piov->iov_len = len; if (len > zerosize) piov->iov_len = zerosize; len -= piov->iov_len; piov++; } piov = auio.uio_iov; } else if ((bp->bio_flags & BIO_VLIST) != 0) { piov = malloc(sizeof(*piov) * bp->bio_ma_n, M_MD, M_WAITOK); auio.uio_iov = piov; vlist = (bus_dma_segment_t *)bp->bio_data; while (len > 0) { piov->iov_base = (void *)(uintptr_t)(vlist->ds_addr + ma_offs); piov->iov_len = vlist->ds_len - ma_offs; if (piov->iov_len > len) piov->iov_len = len; len -= piov->iov_len; ma_offs = 0; vlist++; piov++; } auio.uio_iovcnt = piov - auio.uio_iov; piov = auio.uio_iov; } else if ((bp->bio_flags & BIO_UNMAPPED) != 0) { pb = uma_zalloc(md_pbuf_zone, M_WAITOK); MPASS((pb->b_flags & B_MAXPHYS) != 0); bp->bio_resid = len; unmapped_step: npages = atop(min(maxphys, round_page(len + (ma_offs & PAGE_MASK)))); iolen = min(ptoa(npages) - (ma_offs & PAGE_MASK), len); KASSERT(iolen > 0, ("zero iolen")); pmap_qenter((vm_offset_t)pb->b_data, &bp->bio_ma[atop(ma_offs)], npages); aiov.iov_base = (void *)((vm_offset_t)pb->b_data + (ma_offs & PAGE_MASK)); aiov.iov_len = iolen; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = iolen; } else { aiov.iov_base = bp->bio_data; aiov.iov_len = bp->bio_length; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; } iostart = auio.uio_offset; if (auio.uio_rw == UIO_READ) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); error = VOP_READ(vp, &auio, 0, sc->cred); VOP_UNLOCK(vp); } else { (void) vn_start_write(vp, &mp, V_WAIT); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); error = VOP_WRITE(vp, &auio, sc->flags & MD_ASYNC ? 0 : IO_SYNC, sc->cred); VOP_UNLOCK(vp); vn_finished_write(mp); if (error == 0) sc->flags &= ~MD_VERIFY; } /* When MD_CACHE is set, try to avoid double-caching the data. */ if (error == 0 && (sc->flags & MD_CACHE) == 0) VOP_ADVISE(vp, iostart, auio.uio_offset - 1, POSIX_FADV_DONTNEED); if (pb != NULL) { pmap_qremove((vm_offset_t)pb->b_data, npages); if (error == 0) { len -= iolen; bp->bio_resid -= iolen; ma_offs += iolen; if (len > 0) goto unmapped_step; } uma_zfree(md_pbuf_zone, pb); } else { bp->bio_resid = auio.uio_resid; } free(piov, M_MD); return (error); } static int mdstart_swap(struct md_s *sc, struct bio *bp) { vm_page_t m; u_char *p; vm_pindex_t i, lastp; bus_dma_segment_t *vlist; int rv, ma_offs, offs, len, lastend; switch (bp->bio_cmd) { case BIO_READ: case BIO_WRITE: case BIO_DELETE: break; case BIO_FLUSH: return (0); default: return (EOPNOTSUPP); } p = bp->bio_data; ma_offs = (bp->bio_flags & (BIO_UNMAPPED|BIO_VLIST)) != 0 ? bp->bio_ma_offset : 0; vlist = (bp->bio_flags & BIO_VLIST) != 0 ? (bus_dma_segment_t *)bp->bio_data : NULL; /* * offs is the offset at which to start operating on the * next (ie, first) page. lastp is the last page on * which we're going to operate. lastend is the ending * position within that last page (ie, PAGE_SIZE if * we're operating on complete aligned pages). */ offs = bp->bio_offset % PAGE_SIZE; lastp = (bp->bio_offset + bp->bio_length - 1) / PAGE_SIZE; lastend = (bp->bio_offset + bp->bio_length - 1) % PAGE_SIZE + 1; rv = VM_PAGER_OK; vm_object_pip_add(sc->object, 1); for (i = bp->bio_offset / PAGE_SIZE; i <= lastp; i++) { len = ((i == lastp) ? lastend : PAGE_SIZE) - offs; m = vm_page_grab_unlocked(sc->object, i, VM_ALLOC_SYSTEM); if (bp->bio_cmd == BIO_READ) { if (vm_page_all_valid(m)) rv = VM_PAGER_OK; else rv = vm_pager_get_pages(sc->object, &m, 1, NULL, NULL); if (rv == VM_PAGER_ERROR) { VM_OBJECT_WLOCK(sc->object); vm_page_free(m); VM_OBJECT_WUNLOCK(sc->object); break; } else if (rv == VM_PAGER_FAIL) { /* * Pager does not have the page. Zero * the allocated page, and mark it as * valid. Do not set dirty, the page * can be recreated if thrown out. */ pmap_zero_page(m); vm_page_valid(m); } if ((bp->bio_flags & BIO_UNMAPPED) != 0) { pmap_copy_pages(&m, offs, bp->bio_ma, ma_offs, len); } else if ((bp->bio_flags & BIO_VLIST) != 0) { physcopyout_vlist(VM_PAGE_TO_PHYS(m) + offs, vlist, ma_offs, len); cpu_flush_dcache(p, len); } else { physcopyout(VM_PAGE_TO_PHYS(m) + offs, p, len); cpu_flush_dcache(p, len); } } else if (bp->bio_cmd == BIO_WRITE) { if (len == PAGE_SIZE || vm_page_all_valid(m)) rv = VM_PAGER_OK; else rv = vm_pager_get_pages(sc->object, &m, 1, NULL, NULL); if (rv == VM_PAGER_ERROR) { VM_OBJECT_WLOCK(sc->object); vm_page_free(m); VM_OBJECT_WUNLOCK(sc->object); break; } else if (rv == VM_PAGER_FAIL) pmap_zero_page(m); if ((bp->bio_flags & BIO_UNMAPPED) != 0) { pmap_copy_pages(bp->bio_ma, ma_offs, &m, offs, len); } else if ((bp->bio_flags & BIO_VLIST) != 0) { physcopyin_vlist(vlist, ma_offs, VM_PAGE_TO_PHYS(m) + offs, len); } else { physcopyin(p, VM_PAGE_TO_PHYS(m) + offs, len); } vm_page_valid(m); vm_page_set_dirty(m); } else if (bp->bio_cmd == BIO_DELETE) { if (len == PAGE_SIZE || vm_page_all_valid(m)) rv = VM_PAGER_OK; else rv = vm_pager_get_pages(sc->object, &m, 1, NULL, NULL); VM_OBJECT_WLOCK(sc->object); if (rv == VM_PAGER_ERROR) { vm_page_free(m); VM_OBJECT_WUNLOCK(sc->object); break; } else if (rv == VM_PAGER_FAIL) { vm_page_free(m); m = NULL; } else { /* Page is valid. */ if (len != PAGE_SIZE) { pmap_zero_page_area(m, offs, len); vm_page_set_dirty(m); } else { vm_pager_page_unswapped(m); vm_page_free(m); m = NULL; } } VM_OBJECT_WUNLOCK(sc->object); } if (m != NULL) { /* * The page may be deactivated prior to setting * PGA_REFERENCED, but in this case it will be * reactivated by the page daemon. */ if (vm_page_active(m)) vm_page_reference(m); else vm_page_activate(m); vm_page_xunbusy(m); } /* Actions on further pages start at offset 0 */ p += PAGE_SIZE - offs; offs = 0; ma_offs += len; } vm_object_pip_wakeup(sc->object); return (rv != VM_PAGER_ERROR ? 0 : ENOSPC); } static int mdstart_null(struct md_s *sc, struct bio *bp) { switch (bp->bio_cmd) { case BIO_READ: bzero(bp->bio_data, bp->bio_length); cpu_flush_dcache(bp->bio_data, bp->bio_length); break; case BIO_WRITE: break; } bp->bio_resid = 0; return (0); } static void md_handleattr(struct md_s *sc, struct bio *bp) { if (sc->fwsectors && sc->fwheads && (g_handleattr_int(bp, "GEOM::fwsectors", sc->fwsectors) != 0 || g_handleattr_int(bp, "GEOM::fwheads", sc->fwheads) != 0)) return; if (g_handleattr_int(bp, "GEOM::candelete", 1) != 0) return; if (sc->ident[0] != '\0' && g_handleattr_str(bp, "GEOM::ident", sc->ident) != 0) return; if (g_handleattr_int(bp, "MNT::verified", (sc->flags & MD_VERIFY) != 0)) return; g_io_deliver(bp, EOPNOTSUPP); } static void md_kthread(void *arg) { struct md_s *sc; struct bio *bp; int error; sc = arg; thread_lock(curthread); sched_prio(curthread, PRIBIO); thread_unlock(curthread); if (sc->type == MD_VNODE) curthread->td_pflags |= TDP_NORUNNINGBUF; for (;;) { mtx_lock(&sc->queue_mtx); if (sc->flags & MD_SHUTDOWN) { sc->flags |= MD_EXITING; mtx_unlock(&sc->queue_mtx); kproc_exit(0); } bp = bioq_takefirst(&sc->bio_queue); if (!bp) { msleep(sc, &sc->queue_mtx, PRIBIO | PDROP, "mdwait", 0); continue; } mtx_unlock(&sc->queue_mtx); if (bp->bio_cmd == BIO_GETATTR) { md_handleattr(sc, bp); } else { error = sc->start(sc, bp); if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) { /* * Devstat uses (bio_bcount, bio_resid) for * determining the length of the completed part * of the i/o. g_io_deliver() will translate * from bio_completed to that, but it also * destroys the bio so we must do our own * translation. */ bp->bio_bcount = bp->bio_length; devstat_end_transaction_bio(sc->devstat, bp); } bp->bio_completed = bp->bio_length - bp->bio_resid; g_io_deliver(bp, error); } } } static struct md_s * mdfind(int unit) { struct md_s *sc; LIST_FOREACH(sc, &md_softc_list, list) { if (sc->unit == unit) break; } return (sc); } static struct md_s * mdnew(int unit, int *errp, enum md_types type) { struct md_s *sc; int error; *errp = 0; if (unit == -1) unit = alloc_unr(md_uh); else unit = alloc_unr_specific(md_uh, unit); if (unit == -1) { *errp = EBUSY; return (NULL); } sc = (struct md_s *)malloc(sizeof *sc, M_MD, M_WAITOK | M_ZERO); sc->type = type; bioq_init(&sc->bio_queue); mtx_init(&sc->queue_mtx, "md bio queue", NULL, MTX_DEF); sc->unit = unit; sprintf(sc->name, "md%d", unit); LIST_INSERT_HEAD(&md_softc_list, sc, list); error = kproc_create(md_kthread, sc, &sc->procp, 0, 0,"%s", sc->name); if (error == 0) return (sc); LIST_REMOVE(sc, list); mtx_destroy(&sc->queue_mtx); free_unr(md_uh, sc->unit); free(sc, M_MD); *errp = error; return (NULL); } static void mdinit(struct md_s *sc) { struct g_geom *gp; struct g_provider *pp; g_topology_lock(); gp = g_new_geomf(&g_md_class, "md%d", sc->unit); gp->softc = sc; pp = g_new_providerf(gp, "md%d", sc->unit); devstat_remove_entry(pp->stat); pp->stat = NULL; pp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE; pp->mediasize = sc->mediasize; pp->sectorsize = sc->sectorsize; switch (sc->type) { case MD_MALLOC: case MD_VNODE: case MD_SWAP: pp->flags |= G_PF_ACCEPT_UNMAPPED; break; case MD_PRELOAD: case MD_NULL: break; } sc->gp = gp; sc->pp = pp; sc->devstat = devstat_new_entry("md", sc->unit, sc->sectorsize, DEVSTAT_ALL_SUPPORTED, DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX); sc->devstat->id = pp; g_error_provider(pp, 0); g_topology_unlock(); } static int mdcreate_malloc(struct md_s *sc, struct md_req *mdr) { uintptr_t sp; int error; off_t u; error = 0; if (mdr->md_options & ~(MD_AUTOUNIT | MD_COMPRESS | MD_RESERVE)) return (EINVAL); if (mdr->md_sectorsize != 0 && !powerof2(mdr->md_sectorsize)) return (EINVAL); /* Compression doesn't make sense if we have reserved space */ if (mdr->md_options & MD_RESERVE) mdr->md_options &= ~MD_COMPRESS; if (mdr->md_fwsectors != 0) sc->fwsectors = mdr->md_fwsectors; if (mdr->md_fwheads != 0) sc->fwheads = mdr->md_fwheads; sc->flags = mdr->md_options & (MD_COMPRESS | MD_FORCE); sc->indir = dimension(sc->mediasize / sc->sectorsize); sc->uma = uma_zcreate(sc->name, sc->sectorsize, NULL, NULL, NULL, NULL, 0x1ff, 0); if (mdr->md_options & MD_RESERVE) { off_t nsectors; nsectors = sc->mediasize / sc->sectorsize; for (u = 0; u < nsectors; u++) { sp = (uintptr_t)uma_zalloc(sc->uma, (md_malloc_wait ? M_WAITOK : M_NOWAIT) | M_ZERO); if (sp != 0) error = s_write(sc->indir, u, sp); else error = ENOMEM; if (error != 0) break; } } return (error); } static int mdsetcred(struct md_s *sc, struct ucred *cred) { char *tmpbuf; int error = 0; /* * Set credits in our softc */ if (sc->cred) crfree(sc->cred); sc->cred = crhold(cred); /* * Horrible kludge to establish credentials for NFS XXX. */ if (sc->vnode) { struct uio auio; struct iovec aiov; tmpbuf = malloc(sc->sectorsize, M_TEMP, M_WAITOK); bzero(&auio, sizeof(auio)); aiov.iov_base = tmpbuf; aiov.iov_len = sc->sectorsize; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = 0; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_SYSSPACE; auio.uio_resid = aiov.iov_len; vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY); error = VOP_READ(sc->vnode, &auio, 0, sc->cred); VOP_UNLOCK(sc->vnode); free(tmpbuf, M_TEMP); } return (error); } static int mdcreate_vnode(struct md_s *sc, struct md_req *mdr, struct thread *td) { struct vattr vattr; struct nameidata nd; char *fname; int error, flags; fname = mdr->md_file; if (mdr->md_file_seg == UIO_USERSPACE) { error = copyinstr(fname, sc->file, sizeof(sc->file), NULL); if (error != 0) return (error); } else if (mdr->md_file_seg == UIO_SYSSPACE) strlcpy(sc->file, fname, sizeof(sc->file)); else return (EDOOFUS); /* * If the user specified that this is a read only device, don't * set the FWRITE mask before trying to open the backing store. */ flags = FREAD | ((mdr->md_options & MD_READONLY) ? 0 : FWRITE) \ | ((mdr->md_options & MD_VERIFY) ? O_VERIFY : 0); NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, sc->file, td); error = vn_open(&nd, &flags, 0, NULL); if (error != 0) return (error); NDFREE(&nd, NDF_ONLY_PNBUF); if (nd.ni_vp->v_type != VREG) { error = EINVAL; goto bad; } error = VOP_GETATTR(nd.ni_vp, &vattr, td->td_ucred); if (error != 0) goto bad; if (VOP_ISLOCKED(nd.ni_vp) != LK_EXCLUSIVE) { vn_lock(nd.ni_vp, LK_UPGRADE | LK_RETRY); if (VN_IS_DOOMED(nd.ni_vp)) { /* Forced unmount. */ error = EBADF; goto bad; } } nd.ni_vp->v_vflag |= VV_MD; VOP_UNLOCK(nd.ni_vp); if (mdr->md_fwsectors != 0) sc->fwsectors = mdr->md_fwsectors; if (mdr->md_fwheads != 0) sc->fwheads = mdr->md_fwheads; snprintf(sc->ident, sizeof(sc->ident), "MD-DEV%ju-INO%ju", (uintmax_t)vattr.va_fsid, (uintmax_t)vattr.va_fileid); sc->flags = mdr->md_options & (MD_ASYNC | MD_CACHE | MD_FORCE | MD_VERIFY); if (!(flags & FWRITE)) sc->flags |= MD_READONLY; sc->vnode = nd.ni_vp; error = mdsetcred(sc, td->td_ucred); if (error != 0) { sc->vnode = NULL; vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY); nd.ni_vp->v_vflag &= ~VV_MD; goto bad; } return (0); bad: VOP_UNLOCK(nd.ni_vp); (void)vn_close(nd.ni_vp, flags, td->td_ucred, td); return (error); } static void g_md_providergone(struct g_provider *pp) { struct md_s *sc = pp->geom->softc; mtx_lock(&sc->queue_mtx); sc->flags |= MD_PROVIDERGONE; wakeup(&sc->flags); mtx_unlock(&sc->queue_mtx); } static int mddestroy(struct md_s *sc, struct thread *td) { if (sc->gp) { g_topology_lock(); g_wither_geom(sc->gp, ENXIO); g_topology_unlock(); mtx_lock(&sc->queue_mtx); while (!(sc->flags & MD_PROVIDERGONE)) msleep(&sc->flags, &sc->queue_mtx, PRIBIO, "mddestroy", 0); mtx_unlock(&sc->queue_mtx); } if (sc->devstat) { devstat_remove_entry(sc->devstat); sc->devstat = NULL; } mtx_lock(&sc->queue_mtx); sc->flags |= MD_SHUTDOWN; wakeup(sc); while (!(sc->flags & MD_EXITING)) msleep(sc->procp, &sc->queue_mtx, PRIBIO, "mddestroy", hz / 10); mtx_unlock(&sc->queue_mtx); mtx_destroy(&sc->queue_mtx); if (sc->vnode != NULL) { vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY); sc->vnode->v_vflag &= ~VV_MD; VOP_UNLOCK(sc->vnode); (void)vn_close(sc->vnode, sc->flags & MD_READONLY ? FREAD : (FREAD|FWRITE), sc->cred, td); } if (sc->cred != NULL) crfree(sc->cred); if (sc->object != NULL) vm_object_deallocate(sc->object); if (sc->indir) destroy_indir(sc, sc->indir); if (sc->uma) uma_zdestroy(sc->uma); LIST_REMOVE(sc, list); free_unr(md_uh, sc->unit); free(sc, M_MD); return (0); } static int mdresize(struct md_s *sc, struct md_req *mdr) { int error, res; vm_pindex_t oldpages, newpages; switch (sc->type) { case MD_VNODE: case MD_NULL: break; case MD_SWAP: if (mdr->md_mediasize <= 0 || (mdr->md_mediasize % PAGE_SIZE) != 0) return (EDOM); oldpages = OFF_TO_IDX(sc->mediasize); newpages = OFF_TO_IDX(mdr->md_mediasize); if (newpages < oldpages) { VM_OBJECT_WLOCK(sc->object); vm_object_page_remove(sc->object, newpages, 0, 0); swap_release_by_cred(IDX_TO_OFF(oldpages - newpages), sc->cred); sc->object->charge = IDX_TO_OFF(newpages); sc->object->size = newpages; VM_OBJECT_WUNLOCK(sc->object); } else if (newpages > oldpages) { res = swap_reserve_by_cred(IDX_TO_OFF(newpages - oldpages), sc->cred); if (!res) return (ENOMEM); if ((mdr->md_options & MD_RESERVE) || (sc->flags & MD_RESERVE)) { error = swap_pager_reserve(sc->object, oldpages, newpages - oldpages); if (error < 0) { swap_release_by_cred( IDX_TO_OFF(newpages - oldpages), sc->cred); return (EDOM); } } VM_OBJECT_WLOCK(sc->object); sc->object->charge = IDX_TO_OFF(newpages); sc->object->size = newpages; VM_OBJECT_WUNLOCK(sc->object); } break; default: return (EOPNOTSUPP); } sc->mediasize = mdr->md_mediasize; g_topology_lock(); g_resize_provider(sc->pp, sc->mediasize); g_topology_unlock(); return (0); } static int mdcreate_swap(struct md_s *sc, struct md_req *mdr, struct thread *td) { vm_ooffset_t npage; int error; /* * Range check. Disallow negative sizes and sizes not being * multiple of page size. */ if (sc->mediasize <= 0 || (sc->mediasize % PAGE_SIZE) != 0) return (EDOM); /* * Allocate an OBJT_SWAP object. * * Note the truncation. */ if ((mdr->md_options & MD_VERIFY) != 0) return (EINVAL); npage = mdr->md_mediasize / PAGE_SIZE; if (mdr->md_fwsectors != 0) sc->fwsectors = mdr->md_fwsectors; if (mdr->md_fwheads != 0) sc->fwheads = mdr->md_fwheads; sc->object = vm_pager_allocate(OBJT_SWAP, NULL, PAGE_SIZE * npage, VM_PROT_DEFAULT, 0, td->td_ucred); if (sc->object == NULL) return (ENOMEM); sc->flags = mdr->md_options & (MD_FORCE | MD_RESERVE); if (mdr->md_options & MD_RESERVE) { if (swap_pager_reserve(sc->object, 0, npage) < 0) { error = EDOM; goto finish; } } error = mdsetcred(sc, td->td_ucred); finish: if (error != 0) { vm_object_deallocate(sc->object); sc->object = NULL; } return (error); } static int mdcreate_null(struct md_s *sc, struct md_req *mdr, struct thread *td) { /* * Range check. Disallow negative sizes and sizes not being * multiple of page size. */ if (sc->mediasize <= 0 || (sc->mediasize % PAGE_SIZE) != 0) return (EDOM); return (0); } static int kern_mdattach_locked(struct thread *td, struct md_req *mdr) { struct md_s *sc; unsigned sectsize; int error, i; sx_assert(&md_sx, SA_XLOCKED); switch (mdr->md_type) { case MD_MALLOC: case MD_PRELOAD: case MD_VNODE: case MD_SWAP: case MD_NULL: break; default: return (EINVAL); } if (mdr->md_sectorsize == 0) sectsize = DEV_BSIZE; else sectsize = mdr->md_sectorsize; if (sectsize > maxphys || mdr->md_mediasize < sectsize) return (EINVAL); if (mdr->md_options & MD_AUTOUNIT) sc = mdnew(-1, &error, mdr->md_type); else { if (mdr->md_unit > INT_MAX) return (EINVAL); sc = mdnew(mdr->md_unit, &error, mdr->md_type); } if (sc == NULL) return (error); if (mdr->md_label != NULL) error = copyinstr(mdr->md_label, sc->label, sizeof(sc->label), NULL); if (error != 0) goto err_after_new; if (mdr->md_options & MD_AUTOUNIT) mdr->md_unit = sc->unit; sc->mediasize = mdr->md_mediasize; sc->sectorsize = sectsize; error = EDOOFUS; switch (sc->type) { case MD_MALLOC: sc->start = mdstart_malloc; error = mdcreate_malloc(sc, mdr); break; case MD_PRELOAD: /* * We disallow attaching preloaded memory disks via * ioctl. Preloaded memory disks are automatically * attached in g_md_init(). */ error = EOPNOTSUPP; break; case MD_VNODE: sc->start = mdstart_vnode; error = mdcreate_vnode(sc, mdr, td); break; case MD_SWAP: sc->start = mdstart_swap; error = mdcreate_swap(sc, mdr, td); break; case MD_NULL: sc->start = mdstart_null; error = mdcreate_null(sc, mdr, td); break; } err_after_new: if (error != 0) { mddestroy(sc, td); return (error); } /* Prune off any residual fractional sector */ i = sc->mediasize % sc->sectorsize; sc->mediasize -= i; mdinit(sc); return (0); } static int kern_mdattach(struct thread *td, struct md_req *mdr) { int error; sx_xlock(&md_sx); error = kern_mdattach_locked(td, mdr); sx_xunlock(&md_sx); return (error); } static int kern_mddetach_locked(struct thread *td, struct md_req *mdr) { struct md_s *sc; sx_assert(&md_sx, SA_XLOCKED); if (mdr->md_mediasize != 0 || (mdr->md_options & ~MD_FORCE) != 0) return (EINVAL); sc = mdfind(mdr->md_unit); if (sc == NULL) return (ENOENT); if (sc->opencount != 0 && !(sc->flags & MD_FORCE) && !(mdr->md_options & MD_FORCE)) return (EBUSY); return (mddestroy(sc, td)); } static int kern_mddetach(struct thread *td, struct md_req *mdr) { int error; sx_xlock(&md_sx); error = kern_mddetach_locked(td, mdr); sx_xunlock(&md_sx); return (error); } static int kern_mdresize_locked(struct md_req *mdr) { struct md_s *sc; sx_assert(&md_sx, SA_XLOCKED); if ((mdr->md_options & ~(MD_FORCE | MD_RESERVE)) != 0) return (EINVAL); sc = mdfind(mdr->md_unit); if (sc == NULL) return (ENOENT); if (mdr->md_mediasize < sc->sectorsize) return (EINVAL); mdr->md_mediasize -= mdr->md_mediasize % sc->sectorsize; if (mdr->md_mediasize < sc->mediasize && !(sc->flags & MD_FORCE) && !(mdr->md_options & MD_FORCE)) return (EBUSY); return (mdresize(sc, mdr)); } static int kern_mdresize(struct md_req *mdr) { int error; sx_xlock(&md_sx); error = kern_mdresize_locked(mdr); sx_xunlock(&md_sx); return (error); } static int kern_mdquery_locked(struct md_req *mdr) { struct md_s *sc; int error; sx_assert(&md_sx, SA_XLOCKED); sc = mdfind(mdr->md_unit); if (sc == NULL) return (ENOENT); mdr->md_type = sc->type; mdr->md_options = sc->flags; mdr->md_mediasize = sc->mediasize; mdr->md_sectorsize = sc->sectorsize; error = 0; if (mdr->md_label != NULL) { error = copyout(sc->label, mdr->md_label, strlen(sc->label) + 1); if (error != 0) return (error); } if (sc->type == MD_VNODE || (sc->type == MD_PRELOAD && mdr->md_file != NULL)) error = copyout(sc->file, mdr->md_file, strlen(sc->file) + 1); return (error); } static int kern_mdquery(struct md_req *mdr) { int error; sx_xlock(&md_sx); error = kern_mdquery_locked(mdr); sx_xunlock(&md_sx); return (error); } /* Copy members that are not userspace pointers. */ #define MD_IOCTL2REQ(mdio, mdr) do { \ (mdr)->md_unit = (mdio)->md_unit; \ (mdr)->md_type = (mdio)->md_type; \ (mdr)->md_mediasize = (mdio)->md_mediasize; \ (mdr)->md_sectorsize = (mdio)->md_sectorsize; \ (mdr)->md_options = (mdio)->md_options; \ (mdr)->md_fwheads = (mdio)->md_fwheads; \ (mdr)->md_fwsectors = (mdio)->md_fwsectors; \ (mdr)->md_units = &(mdio)->md_pad[0]; \ (mdr)->md_units_nitems = nitems((mdio)->md_pad); \ } while(0) /* Copy members that might have been updated */ #define MD_REQ2IOCTL(mdr, mdio) do { \ (mdio)->md_unit = (mdr)->md_unit; \ (mdio)->md_type = (mdr)->md_type; \ (mdio)->md_mediasize = (mdr)->md_mediasize; \ (mdio)->md_sectorsize = (mdr)->md_sectorsize; \ (mdio)->md_options = (mdr)->md_options; \ (mdio)->md_fwheads = (mdr)->md_fwheads; \ (mdio)->md_fwsectors = (mdr)->md_fwsectors; \ } while(0) static int mdctlioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td) { struct md_req mdr; int error; if (md_debug) printf("mdctlioctl(%s %lx %p %x %p)\n", devtoname(dev), cmd, addr, flags, td); bzero(&mdr, sizeof(mdr)); switch (cmd) { case MDIOCATTACH: case MDIOCDETACH: case MDIOCRESIZE: case MDIOCQUERY: { struct md_ioctl *mdio = (struct md_ioctl *)addr; if (mdio->md_version != MDIOVERSION) return (EINVAL); MD_IOCTL2REQ(mdio, &mdr); mdr.md_file = mdio->md_file; mdr.md_file_seg = UIO_USERSPACE; /* If the file is adjacent to the md_ioctl it's in kernel. */ if ((void *)mdio->md_file == (void *)(mdio + 1)) mdr.md_file_seg = UIO_SYSSPACE; mdr.md_label = mdio->md_label; break; } #ifdef COMPAT_FREEBSD32 case MDIOCATTACH_32: case MDIOCDETACH_32: case MDIOCRESIZE_32: case MDIOCQUERY_32: { struct md_ioctl32 *mdio = (struct md_ioctl32 *)addr; if (mdio->md_version != MDIOVERSION) return (EINVAL); MD_IOCTL2REQ(mdio, &mdr); mdr.md_file = (void *)(uintptr_t)mdio->md_file; mdr.md_file_seg = UIO_USERSPACE; mdr.md_label = (void *)(uintptr_t)mdio->md_label; break; } #endif default: /* Fall through to handler switch. */ break; } error = 0; switch (cmd) { case MDIOCATTACH: #ifdef COMPAT_FREEBSD32 case MDIOCATTACH_32: #endif error = kern_mdattach(td, &mdr); break; case MDIOCDETACH: #ifdef COMPAT_FREEBSD32 case MDIOCDETACH_32: #endif error = kern_mddetach(td, &mdr); break; case MDIOCRESIZE: #ifdef COMPAT_FREEBSD32 case MDIOCRESIZE_32: #endif error = kern_mdresize(&mdr); break; case MDIOCQUERY: #ifdef COMPAT_FREEBSD32 case MDIOCQUERY_32: #endif error = kern_mdquery(&mdr); break; default: error = ENOIOCTL; } switch (cmd) { case MDIOCATTACH: case MDIOCQUERY: { struct md_ioctl *mdio = (struct md_ioctl *)addr; MD_REQ2IOCTL(&mdr, mdio); break; } #ifdef COMPAT_FREEBSD32 case MDIOCATTACH_32: case MDIOCQUERY_32: { struct md_ioctl32 *mdio = (struct md_ioctl32 *)addr; MD_REQ2IOCTL(&mdr, mdio); break; } #endif default: /* Other commands to not alter mdr. */ break; } return (error); } static void md_preloaded(u_char *image, size_t length, const char *name) { struct md_s *sc; int error; sc = mdnew(-1, &error, MD_PRELOAD); if (sc == NULL) return; sc->mediasize = length; sc->sectorsize = DEV_BSIZE; sc->pl_ptr = image; sc->pl_len = length; sc->start = mdstart_preload; if (name != NULL) strlcpy(sc->file, name, sizeof(sc->file)); #ifdef MD_ROOT if (sc->unit == 0) { #ifndef ROOTDEVNAME rootdevnames[0] = MD_ROOT_FSTYPE ":/dev/md0"; #endif #ifdef MD_ROOT_READONLY sc->flags |= MD_READONLY; #endif } #endif mdinit(sc); if (name != NULL) { printf("%s%d: Preloaded image <%s> %zd bytes at %p\n", MD_NAME, sc->unit, name, length, image); } else { printf("%s%d: Embedded image %zd bytes at %p\n", MD_NAME, sc->unit, length, image); } } static void g_md_init(struct g_class *mp __unused) { caddr_t mod; u_char *ptr, *name, *type; unsigned len; int i; /* figure out log2(NINDIR) */ for (i = NINDIR, nshift = -1; i; nshift++) i >>= 1; mod = NULL; sx_init(&md_sx, "MD config lock"); g_topology_unlock(); md_uh = new_unrhdr(0, INT_MAX, NULL); #ifdef MD_ROOT if (mfs_root_size != 0) { sx_xlock(&md_sx); #ifdef MD_ROOT_MEM md_preloaded(mfs_root, mfs_root_size, NULL); #else md_preloaded(__DEVOLATILE(u_char *, &mfs_root), mfs_root_size, NULL); #endif sx_xunlock(&md_sx); } #endif /* XXX: are preload_* static or do they need Giant ? */ while ((mod = preload_search_next_name(mod)) != NULL) { name = (char *)preload_search_info(mod, MODINFO_NAME); if (name == NULL) continue; type = (char *)preload_search_info(mod, MODINFO_TYPE); if (type == NULL) continue; if (strcmp(type, "md_image") && strcmp(type, "mfs_root")) continue; ptr = preload_fetch_addr(mod); len = preload_fetch_size(mod); if (ptr != NULL && len != 0) { sx_xlock(&md_sx); md_preloaded(ptr, len, name); sx_xunlock(&md_sx); } } md_pbuf_zone = pbuf_zsecond_create("mdpbuf", nswbuf / 10); status_dev = make_dev(&mdctl_cdevsw, INT_MAX, UID_ROOT, GID_WHEEL, 0600, MDCTL_NAME); g_topology_lock(); } static void g_md_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp) { struct md_s *mp; char *type; mp = gp->softc; if (mp == NULL) return; switch (mp->type) { case MD_MALLOC: type = "malloc"; break; case MD_PRELOAD: type = "preload"; break; case MD_VNODE: type = "vnode"; break; case MD_SWAP: type = "swap"; break; case MD_NULL: type = "null"; break; default: type = "unknown"; break; } if (pp != NULL) { if (indent == NULL) { sbuf_printf(sb, " u %d", mp->unit); sbuf_printf(sb, " s %ju", (uintmax_t) mp->sectorsize); sbuf_printf(sb, " f %ju", (uintmax_t) mp->fwheads); sbuf_printf(sb, " fs %ju", (uintmax_t) mp->fwsectors); sbuf_printf(sb, " l %ju", (uintmax_t) mp->mediasize); sbuf_printf(sb, " t %s", type); if ((mp->type == MD_VNODE && mp->vnode != NULL) || (mp->type == MD_PRELOAD && mp->file[0] != '\0')) sbuf_printf(sb, " file %s", mp->file); sbuf_printf(sb, " label %s", mp->label); } else { sbuf_printf(sb, "%s%d\n", indent, mp->unit); sbuf_printf(sb, "%s%ju\n", indent, (uintmax_t) mp->sectorsize); sbuf_printf(sb, "%s%ju\n", indent, (uintmax_t) mp->fwheads); sbuf_printf(sb, "%s%ju\n", indent, (uintmax_t) mp->fwsectors); if (mp->ident[0] != '\0') { sbuf_printf(sb, "%s", indent); g_conf_printf_escaped(sb, "%s", mp->ident); sbuf_printf(sb, "\n"); } sbuf_printf(sb, "%s%ju\n", indent, (uintmax_t) mp->mediasize); sbuf_printf(sb, "%s%s\n", indent, (mp->flags & MD_COMPRESS) == 0 ? "off": "on"); sbuf_printf(sb, "%s%s\n", indent, (mp->flags & MD_READONLY) == 0 ? "read-write": "read-only"); sbuf_printf(sb, "%s%s\n", indent, type); if ((mp->type == MD_VNODE && mp->vnode != NULL) || (mp->type == MD_PRELOAD && mp->file[0] != '\0')) { sbuf_printf(sb, "%s", indent); g_conf_printf_escaped(sb, "%s", mp->file); sbuf_printf(sb, "\n"); } if (mp->type == MD_VNODE) sbuf_printf(sb, "%s%s\n", indent, (mp->flags & MD_CACHE) == 0 ? "off": "on"); sbuf_printf(sb, "%s\n"); } } } static void g_md_fini(struct g_class *mp __unused) { sx_destroy(&md_sx); if (status_dev != NULL) destroy_dev(status_dev); uma_zdestroy(md_pbuf_zone); delete_unrhdr(md_uh); } diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c index 97803afc40fe..e7097be7b115 100644 --- a/sys/vm/vm_object.c +++ b/sys/vm/vm_object.c @@ -1,2902 +1,2917 @@ /*- * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) * * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * The Mach Operating System project at Carnegie-Mellon University. * * 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. 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: @(#)vm_object.c 8.5 (Berkeley) 3/22/94 * * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * Authors: Avadis Tevanian, Jr., Michael Wayne Young * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * Virtual memory object module. */ #include __FBSDID("$FreeBSD$"); #include "opt_vm.h" #include #include #include #include #include #include #include #include #include #include #include #include #include /* for curproc, pageproc */ #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 static int old_msync; SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0, "Use old (insecure) msync behavior"); static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags, int flags, boolean_t *allclean, boolean_t *eio); static boolean_t vm_object_page_remove_write(vm_page_t p, int flags, boolean_t *allclean); static void vm_object_backing_remove(vm_object_t object); /* * Virtual memory objects maintain the actual data * associated with allocated virtual memory. A given * page of memory exists within exactly one object. * * An object is only deallocated when all "references" * are given up. Only one "reference" to a given * region of an object should be writeable. * * Associated with each object is a list of all resident * memory pages belonging to that object; this list is * maintained by the "vm_page" module, and locked by the object's * lock. * * Each object also records a "pager" routine which is * used to retrieve (and store) pages to the proper backing * storage. In addition, objects may be backed by other * objects from which they were virtual-copied. * * The only items within the object structure which are * modified after time of creation are: * reference count locked by object's lock * pager routine locked by object's lock * */ struct object_q vm_object_list; struct mtx vm_object_list_mtx; /* lock for object list and count */ struct vm_object kernel_object_store; static SYSCTL_NODE(_vm_stats, OID_AUTO, object, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "VM object stats"); static COUNTER_U64_DEFINE_EARLY(object_collapses); SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, collapses, CTLFLAG_RD, &object_collapses, "VM object collapses"); static COUNTER_U64_DEFINE_EARLY(object_bypasses); SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, bypasses, CTLFLAG_RD, &object_bypasses, "VM object bypasses"); static COUNTER_U64_DEFINE_EARLY(object_collapse_waits); SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, collapse_waits, CTLFLAG_RD, &object_collapse_waits, "Number of sleeps for collapse"); static uma_zone_t obj_zone; static int vm_object_zinit(void *mem, int size, int flags); #ifdef INVARIANTS static void vm_object_zdtor(void *mem, int size, void *arg); static void vm_object_zdtor(void *mem, int size, void *arg) { vm_object_t object; object = (vm_object_t)mem; KASSERT(object->ref_count == 0, ("object %p ref_count = %d", object, object->ref_count)); KASSERT(TAILQ_EMPTY(&object->memq), ("object %p has resident pages in its memq", object)); KASSERT(vm_radix_is_empty(&object->rtree), ("object %p has resident pages in its trie", object)); #if VM_NRESERVLEVEL > 0 KASSERT(LIST_EMPTY(&object->rvq), ("object %p has reservations", object)); #endif KASSERT(!vm_object_busied(object), ("object %p busy = %d", object, blockcount_read(&object->busy))); KASSERT(object->resident_page_count == 0, ("object %p resident_page_count = %d", object, object->resident_page_count)); KASSERT(atomic_load_int(&object->shadow_count) == 0, ("object %p shadow_count = %d", object, atomic_load_int(&object->shadow_count))); KASSERT(object->type == OBJT_DEAD, ("object %p has non-dead type %d", object, object->type)); KASSERT(object->charge == 0 && object->cred == NULL, ("object %p has non-zero charge %ju (%p)", object, (uintmax_t)object->charge, object->cred)); } #endif static int vm_object_zinit(void *mem, int size, int flags) { vm_object_t object; object = (vm_object_t)mem; rw_init_flags(&object->lock, "vm object", RW_DUPOK | RW_NEW); /* These are true for any object that has been freed */ object->type = OBJT_DEAD; vm_radix_init(&object->rtree); refcount_init(&object->ref_count, 0); blockcount_init(&object->paging_in_progress); blockcount_init(&object->busy); object->resident_page_count = 0; atomic_store_int(&object->shadow_count, 0); object->flags = OBJ_DEAD; mtx_lock(&vm_object_list_mtx); TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); mtx_unlock(&vm_object_list_mtx); return (0); } static void _vm_object_allocate(objtype_t type, vm_pindex_t size, u_short flags, vm_object_t object, void *handle) { TAILQ_INIT(&object->memq); LIST_INIT(&object->shadow_head); object->type = type; object->flags = flags; if ((flags & OBJ_SWAP) != 0) pctrie_init(&object->un_pager.swp.swp_blks); /* * Ensure that swap_pager_swapoff() iteration over object_list * sees up to date type and pctrie head if it observed * non-dead object. */ atomic_thread_fence_rel(); object->pg_color = 0; object->size = size; object->domain.dr_policy = NULL; object->generation = 1; object->cleangeneration = 1; refcount_init(&object->ref_count, 1); object->memattr = VM_MEMATTR_DEFAULT; object->cred = NULL; object->charge = 0; object->handle = handle; object->backing_object = NULL; object->backing_object_offset = (vm_ooffset_t) 0; #if VM_NRESERVLEVEL > 0 LIST_INIT(&object->rvq); #endif umtx_shm_object_init(object); } /* * vm_object_init: * * Initialize the VM objects module. */ void vm_object_init(void) { TAILQ_INIT(&vm_object_list); mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF); rw_init(&kernel_object->lock, "kernel vm object"); _vm_object_allocate(OBJT_PHYS, atop(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), OBJ_UNMANAGED, kernel_object, NULL); #if VM_NRESERVLEVEL > 0 kernel_object->flags |= OBJ_COLORED; kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS); #endif kernel_object->un_pager.phys.ops = &default_phys_pg_ops; /* * The lock portion of struct vm_object must be type stable due * to vm_pageout_fallback_object_lock locking a vm object * without holding any references to it. * * paging_in_progress is valid always. Lockless references to * the objects may acquire pip and then check OBJ_DEAD. */ obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL, #ifdef INVARIANTS vm_object_zdtor, #else NULL, #endif vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); vm_radix_zinit(); } void vm_object_clear_flag(vm_object_t object, u_short bits) { VM_OBJECT_ASSERT_WLOCKED(object); object->flags &= ~bits; } /* * Sets the default memory attribute for the specified object. Pages * that are allocated to this object are by default assigned this memory * attribute. * * Presently, this function must be called before any pages are allocated * to the object. In the future, this requirement may be relaxed for * "default" and "swap" objects. */ int vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr) { VM_OBJECT_ASSERT_WLOCKED(object); if (object->type == OBJT_DEAD) return (KERN_INVALID_ARGUMENT); if (!TAILQ_EMPTY(&object->memq)) return (KERN_FAILURE); object->memattr = memattr; return (KERN_SUCCESS); } void vm_object_pip_add(vm_object_t object, short i) { if (i > 0) blockcount_acquire(&object->paging_in_progress, i); } void vm_object_pip_wakeup(vm_object_t object) { vm_object_pip_wakeupn(object, 1); } void vm_object_pip_wakeupn(vm_object_t object, short i) { if (i > 0) blockcount_release(&object->paging_in_progress, i); } /* * Atomically drop the object lock and wait for pip to drain. This protects * from sleep/wakeup races due to identity changes. The lock is not re-acquired * on return. */ static void vm_object_pip_sleep(vm_object_t object, const char *waitid) { (void)blockcount_sleep(&object->paging_in_progress, &object->lock, waitid, PVM | PDROP); } void vm_object_pip_wait(vm_object_t object, const char *waitid) { VM_OBJECT_ASSERT_WLOCKED(object); blockcount_wait(&object->paging_in_progress, &object->lock, waitid, PVM); } void vm_object_pip_wait_unlocked(vm_object_t object, const char *waitid) { VM_OBJECT_ASSERT_UNLOCKED(object); blockcount_wait(&object->paging_in_progress, NULL, waitid, PVM); } /* * vm_object_allocate: * * Returns a new object with the given size. */ vm_object_t vm_object_allocate(objtype_t type, vm_pindex_t size) { vm_object_t object; u_short flags; switch (type) { case OBJT_DEAD: panic("vm_object_allocate: can't create OBJT_DEAD"); case OBJT_DEFAULT: flags = OBJ_COLORED; break; case OBJT_SWAP: flags = OBJ_COLORED | OBJ_SWAP; break; case OBJT_DEVICE: case OBJT_SG: flags = OBJ_FICTITIOUS | OBJ_UNMANAGED; break; case OBJT_MGTDEVICE: flags = OBJ_FICTITIOUS; break; case OBJT_PHYS: flags = OBJ_UNMANAGED; break; case OBJT_VNODE: flags = 0; break; default: panic("vm_object_allocate: type %d is undefined or dynamic", type); } object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK); _vm_object_allocate(type, size, flags, object, NULL); return (object); } vm_object_t vm_object_allocate_dyn(objtype_t dyntype, vm_pindex_t size, u_short flags) { vm_object_t object; MPASS(dyntype >= OBJT_FIRST_DYN /* && dyntype < nitems(pagertab) */); object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK); _vm_object_allocate(dyntype, size, flags, object, NULL); return (object); } /* * vm_object_allocate_anon: * * Returns a new default object of the given size and marked as * anonymous memory for special split/collapse handling. Color * to be initialized by the caller. */ vm_object_t vm_object_allocate_anon(vm_pindex_t size, vm_object_t backing_object, struct ucred *cred, vm_size_t charge) { vm_object_t handle, object; if (backing_object == NULL) handle = NULL; else if ((backing_object->flags & OBJ_ANON) != 0) handle = backing_object->handle; else handle = backing_object; object = uma_zalloc(obj_zone, M_WAITOK); _vm_object_allocate(OBJT_DEFAULT, size, OBJ_ANON | OBJ_ONEMAPPING, object, handle); object->cred = cred; object->charge = cred != NULL ? charge : 0; return (object); } static void vm_object_reference_vnode(vm_object_t object) { u_int old; /* * vnode objects need the lock for the first reference * to serialize with vnode_object_deallocate(). */ if (!refcount_acquire_if_gt(&object->ref_count, 0)) { VM_OBJECT_RLOCK(object); old = refcount_acquire(&object->ref_count); if (object->type == OBJT_VNODE && old == 0) vref(object->handle); VM_OBJECT_RUNLOCK(object); } } /* * vm_object_reference: * * Acquires a reference to the given object. */ void vm_object_reference(vm_object_t object) { if (object == NULL) return; if (object->type == OBJT_VNODE) vm_object_reference_vnode(object); else refcount_acquire(&object->ref_count); KASSERT((object->flags & OBJ_DEAD) == 0, ("vm_object_reference: Referenced dead object.")); } /* * vm_object_reference_locked: * * Gets another reference to the given object. * * The object must be locked. */ void vm_object_reference_locked(vm_object_t object) { u_int old; VM_OBJECT_ASSERT_LOCKED(object); old = refcount_acquire(&object->ref_count); if (object->type == OBJT_VNODE && old == 0) vref(object->handle); KASSERT((object->flags & OBJ_DEAD) == 0, ("vm_object_reference: Referenced dead object.")); } /* * Handle deallocating an object of type OBJT_VNODE. */ static void vm_object_deallocate_vnode(vm_object_t object) { struct vnode *vp = (struct vnode *) object->handle; bool last; KASSERT(object->type == OBJT_VNODE, ("vm_object_deallocate_vnode: not a vnode object")); KASSERT(vp != NULL, ("vm_object_deallocate_vnode: missing vp")); /* Object lock to protect handle lookup. */ last = refcount_release(&object->ref_count); VM_OBJECT_RUNLOCK(object); if (!last) return; if (!umtx_shm_vnobj_persistent) umtx_shm_object_terminated(object); /* vrele may need the vnode lock. */ vrele(vp); } /* * We dropped a reference on an object and discovered that it had a * single remaining shadow. This is a sibling of the reference we * dropped. Attempt to collapse the sibling and backing object. */ static vm_object_t vm_object_deallocate_anon(vm_object_t backing_object) { vm_object_t object; /* Fetch the final shadow. */ object = LIST_FIRST(&backing_object->shadow_head); KASSERT(object != NULL && atomic_load_int(&backing_object->shadow_count) == 1, ("vm_object_anon_deallocate: ref_count: %d, shadow_count: %d", backing_object->ref_count, atomic_load_int(&backing_object->shadow_count))); KASSERT((object->flags & OBJ_ANON) != 0, ("invalid shadow object %p", object)); if (!VM_OBJECT_TRYWLOCK(object)) { /* * Prevent object from disappearing since we do not have a * reference. */ vm_object_pip_add(object, 1); VM_OBJECT_WUNLOCK(backing_object); VM_OBJECT_WLOCK(object); vm_object_pip_wakeup(object); } else VM_OBJECT_WUNLOCK(backing_object); /* * Check for a collapse/terminate race with the last reference holder. */ if ((object->flags & (OBJ_DEAD | OBJ_COLLAPSING)) != 0 || !refcount_acquire_if_not_zero(&object->ref_count)) { VM_OBJECT_WUNLOCK(object); return (NULL); } backing_object = object->backing_object; if (backing_object != NULL && (backing_object->flags & OBJ_ANON) != 0) vm_object_collapse(object); VM_OBJECT_WUNLOCK(object); return (object); } /* * vm_object_deallocate: * * Release a reference to the specified object, * gained either through a vm_object_allocate * or a vm_object_reference call. When all references * are gone, storage associated with this object * may be relinquished. * * No object may be locked. */ void vm_object_deallocate(vm_object_t object) { vm_object_t temp; bool released; while (object != NULL) { /* * If the reference count goes to 0 we start calling * vm_object_terminate() on the object chain. A ref count * of 1 may be a special case depending on the shadow count * being 0 or 1. These cases require a write lock on the * object. */ if ((object->flags & OBJ_ANON) == 0) released = refcount_release_if_gt(&object->ref_count, 1); else released = refcount_release_if_gt(&object->ref_count, 2); if (released) return; if (object->type == OBJT_VNODE) { VM_OBJECT_RLOCK(object); if (object->type == OBJT_VNODE) { vm_object_deallocate_vnode(object); return; } VM_OBJECT_RUNLOCK(object); } VM_OBJECT_WLOCK(object); KASSERT(object->ref_count > 0, ("vm_object_deallocate: object deallocated too many times: %d", object->type)); /* * If this is not the final reference to an anonymous * object we may need to collapse the shadow chain. */ if (!refcount_release(&object->ref_count)) { if (object->ref_count > 1 || atomic_load_int(&object->shadow_count) == 0) { if ((object->flags & OBJ_ANON) != 0 && object->ref_count == 1) vm_object_set_flag(object, OBJ_ONEMAPPING); VM_OBJECT_WUNLOCK(object); return; } /* Handle collapsing last ref on anonymous objects. */ object = vm_object_deallocate_anon(object); continue; } /* * Handle the final reference to an object. We restart * the loop with the backing object to avoid recursion. */ umtx_shm_object_terminated(object); temp = object->backing_object; if (temp != NULL) { KASSERT(object->type == OBJT_DEFAULT || object->type == OBJT_SWAP, ("shadowed tmpfs v_object 2 %p", object)); vm_object_backing_remove(object); } KASSERT((object->flags & OBJ_DEAD) == 0, ("vm_object_deallocate: Terminating dead object.")); vm_object_set_flag(object, OBJ_DEAD); vm_object_terminate(object); object = temp; } } /* * vm_object_destroy removes the object from the global object list * and frees the space for the object. */ void vm_object_destroy(vm_object_t object) { /* * Release the allocation charge. */ if (object->cred != NULL) { swap_release_by_cred(object->charge, object->cred); object->charge = 0; crfree(object->cred); object->cred = NULL; } /* * Free the space for the object. */ uma_zfree(obj_zone, object); } static void vm_object_sub_shadow(vm_object_t object) { KASSERT(object->shadow_count >= 1, ("object %p sub_shadow count zero", object)); atomic_subtract_int(&object->shadow_count, 1); } static void vm_object_backing_remove_locked(vm_object_t object) { vm_object_t backing_object; backing_object = object->backing_object; VM_OBJECT_ASSERT_WLOCKED(object); VM_OBJECT_ASSERT_WLOCKED(backing_object); KASSERT((object->flags & OBJ_COLLAPSING) == 0, ("vm_object_backing_remove: Removing collapsing object.")); vm_object_sub_shadow(backing_object); if ((object->flags & OBJ_SHADOWLIST) != 0) { LIST_REMOVE(object, shadow_list); vm_object_clear_flag(object, OBJ_SHADOWLIST); } object->backing_object = NULL; } static void vm_object_backing_remove(vm_object_t object) { vm_object_t backing_object; VM_OBJECT_ASSERT_WLOCKED(object); backing_object = object->backing_object; if ((object->flags & OBJ_SHADOWLIST) != 0) { VM_OBJECT_WLOCK(backing_object); vm_object_backing_remove_locked(object); VM_OBJECT_WUNLOCK(backing_object); } else { object->backing_object = NULL; vm_object_sub_shadow(backing_object); } } static void vm_object_backing_insert_locked(vm_object_t object, vm_object_t backing_object) { VM_OBJECT_ASSERT_WLOCKED(object); atomic_add_int(&backing_object->shadow_count, 1); if ((backing_object->flags & OBJ_ANON) != 0) { VM_OBJECT_ASSERT_WLOCKED(backing_object); LIST_INSERT_HEAD(&backing_object->shadow_head, object, shadow_list); vm_object_set_flag(object, OBJ_SHADOWLIST); } object->backing_object = backing_object; } static void vm_object_backing_insert(vm_object_t object, vm_object_t backing_object) { VM_OBJECT_ASSERT_WLOCKED(object); if ((backing_object->flags & OBJ_ANON) != 0) { VM_OBJECT_WLOCK(backing_object); vm_object_backing_insert_locked(object, backing_object); VM_OBJECT_WUNLOCK(backing_object); } else { object->backing_object = backing_object; atomic_add_int(&backing_object->shadow_count, 1); } } /* * Insert an object into a backing_object's shadow list with an additional * reference to the backing_object added. */ static void vm_object_backing_insert_ref(vm_object_t object, vm_object_t backing_object) { VM_OBJECT_ASSERT_WLOCKED(object); if ((backing_object->flags & OBJ_ANON) != 0) { VM_OBJECT_WLOCK(backing_object); KASSERT((backing_object->flags & OBJ_DEAD) == 0, ("shadowing dead anonymous object")); vm_object_reference_locked(backing_object); vm_object_backing_insert_locked(object, backing_object); vm_object_clear_flag(backing_object, OBJ_ONEMAPPING); VM_OBJECT_WUNLOCK(backing_object); } else { vm_object_reference(backing_object); atomic_add_int(&backing_object->shadow_count, 1); object->backing_object = backing_object; } } /* * Transfer a backing reference from backing_object to object. */ static void vm_object_backing_transfer(vm_object_t object, vm_object_t backing_object) { vm_object_t new_backing_object; /* * Note that the reference to backing_object->backing_object * moves from within backing_object to within object. */ vm_object_backing_remove_locked(object); new_backing_object = backing_object->backing_object; if (new_backing_object == NULL) return; if ((new_backing_object->flags & OBJ_ANON) != 0) { VM_OBJECT_WLOCK(new_backing_object); vm_object_backing_remove_locked(backing_object); vm_object_backing_insert_locked(object, new_backing_object); VM_OBJECT_WUNLOCK(new_backing_object); } else { /* * shadow_count for new_backing_object is left * unchanged, its reference provided by backing_object * is replaced by object. */ object->backing_object = new_backing_object; backing_object->backing_object = NULL; } } /* * Wait for a concurrent collapse to settle. */ static void vm_object_collapse_wait(vm_object_t object) { VM_OBJECT_ASSERT_WLOCKED(object); while ((object->flags & OBJ_COLLAPSING) != 0) { vm_object_pip_wait(object, "vmcolwait"); counter_u64_add(object_collapse_waits, 1); } } /* * Waits for a backing object to clear a pending collapse and returns * it locked if it is an ANON object. */ static vm_object_t vm_object_backing_collapse_wait(vm_object_t object) { vm_object_t backing_object; VM_OBJECT_ASSERT_WLOCKED(object); for (;;) { backing_object = object->backing_object; if (backing_object == NULL || (backing_object->flags & OBJ_ANON) == 0) return (NULL); VM_OBJECT_WLOCK(backing_object); if ((backing_object->flags & (OBJ_DEAD | OBJ_COLLAPSING)) == 0) break; VM_OBJECT_WUNLOCK(object); vm_object_pip_sleep(backing_object, "vmbckwait"); counter_u64_add(object_collapse_waits, 1); VM_OBJECT_WLOCK(object); } return (backing_object); } /* * vm_object_terminate_pages removes any remaining pageable pages * from the object and resets the object to an empty state. */ static void vm_object_terminate_pages(vm_object_t object) { vm_page_t p, p_next; VM_OBJECT_ASSERT_WLOCKED(object); /* * Free any remaining pageable pages. This also removes them from the * paging queues. However, don't free wired pages, just remove them * from the object. Rather than incrementally removing each page from * the object, the page and object are reset to any empty state. */ TAILQ_FOREACH_SAFE(p, &object->memq, listq, p_next) { vm_page_assert_unbusied(p); KASSERT(p->object == object && (p->ref_count & VPRC_OBJREF) != 0, ("vm_object_terminate_pages: page %p is inconsistent", p)); p->object = NULL; if (vm_page_drop(p, VPRC_OBJREF) == VPRC_OBJREF) { VM_CNT_INC(v_pfree); vm_page_free(p); } } /* * If the object contained any pages, then reset it to an empty state. * None of the object's fields, including "resident_page_count", were * modified by the preceding loop. */ if (object->resident_page_count != 0) { vm_radix_reclaim_allnodes(&object->rtree); TAILQ_INIT(&object->memq); object->resident_page_count = 0; if (object->type == OBJT_VNODE) vdrop(object->handle); } } /* * vm_object_terminate actually destroys the specified object, freeing * up all previously used resources. * * The object must be locked. * This routine may block. */ void vm_object_terminate(vm_object_t object) { VM_OBJECT_ASSERT_WLOCKED(object); KASSERT((object->flags & OBJ_DEAD) != 0, ("terminating non-dead obj %p", object)); KASSERT((object->flags & OBJ_COLLAPSING) == 0, ("terminating collapsing obj %p", object)); KASSERT(object->backing_object == NULL, ("terminating shadow obj %p", object)); /* * Wait for the pageout daemon and other current users to be * done with the object. Note that new paging_in_progress * users can come after this wait, but they must check * OBJ_DEAD flag set (without unlocking the object), and avoid * the object being terminated. */ vm_object_pip_wait(object, "objtrm"); KASSERT(object->ref_count == 0, ("vm_object_terminate: object with references, ref_count=%d", object->ref_count)); if ((object->flags & OBJ_PG_DTOR) == 0) vm_object_terminate_pages(object); #if VM_NRESERVLEVEL > 0 if (__predict_false(!LIST_EMPTY(&object->rvq))) vm_reserv_break_all(object); #endif KASSERT(object->cred == NULL || object->type == OBJT_DEFAULT || (object->flags & OBJ_SWAP) != 0, ("%s: non-swap obj %p has cred", __func__, object)); /* * Let the pager know object is dead. */ vm_pager_deallocate(object); VM_OBJECT_WUNLOCK(object); vm_object_destroy(object); } /* * Make the page read-only so that we can clear the object flags. However, if * this is a nosync mmap then the object is likely to stay dirty so do not * mess with the page and do not clear the object flags. Returns TRUE if the * page should be flushed, and FALSE otherwise. */ static boolean_t vm_object_page_remove_write(vm_page_t p, int flags, boolean_t *allclean) { vm_page_assert_busied(p); /* * If we have been asked to skip nosync pages and this is a * nosync page, skip it. Note that the object flags were not * cleared in this case so we do not have to set them. */ if ((flags & OBJPC_NOSYNC) != 0 && (p->a.flags & PGA_NOSYNC) != 0) { *allclean = FALSE; return (FALSE); } else { pmap_remove_write(p); return (p->dirty != 0); } } /* * vm_object_page_clean * * Clean all dirty pages in the specified range of object. Leaves page * on whatever queue it is currently on. If NOSYNC is set then do not * write out pages with PGA_NOSYNC set (originally comes from MAP_NOSYNC), * leaving the object dirty. * * For swap objects backing tmpfs regular files, do not flush anything, * but remove write protection on the mapped pages to update mtime through * mmaped writes. * * When stuffing pages asynchronously, allow clustering. XXX we need a * synchronous clustering mode implementation. * * Odd semantics: if start == end, we clean everything. * * The object must be locked. * * Returns FALSE if some page from the range was not written, as * reported by the pager, and TRUE otherwise. */ boolean_t vm_object_page_clean(vm_object_t object, vm_ooffset_t start, vm_ooffset_t end, int flags) { vm_page_t np, p; vm_pindex_t pi, tend, tstart; int curgeneration, n, pagerflags; boolean_t eio, res, allclean; VM_OBJECT_ASSERT_WLOCKED(object); if (!vm_object_mightbedirty(object) || object->resident_page_count == 0) return (TRUE); pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) != 0 ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; pagerflags |= (flags & OBJPC_INVAL) != 0 ? VM_PAGER_PUT_INVAL : 0; tstart = OFF_TO_IDX(start); tend = (end == 0) ? object->size : OFF_TO_IDX(end + PAGE_MASK); allclean = tstart == 0 && tend >= object->size; res = TRUE; rescan: curgeneration = object->generation; for (p = vm_page_find_least(object, tstart); p != NULL; p = np) { pi = p->pindex; if (pi >= tend) break; np = TAILQ_NEXT(p, listq); if (vm_page_none_valid(p)) continue; if (vm_page_busy_acquire(p, VM_ALLOC_WAITFAIL) == 0) { if (object->generation != curgeneration && (flags & OBJPC_SYNC) != 0) goto rescan; np = vm_page_find_least(object, pi); continue; } if (!vm_object_page_remove_write(p, flags, &allclean)) { vm_page_xunbusy(p); continue; } if (object->type == OBJT_VNODE) { n = vm_object_page_collect_flush(object, p, pagerflags, flags, &allclean, &eio); if (eio) { res = FALSE; allclean = FALSE; } if (object->generation != curgeneration && (flags & OBJPC_SYNC) != 0) goto rescan; /* * If the VOP_PUTPAGES() did a truncated write, so * that even the first page of the run is not fully * written, vm_pageout_flush() returns 0 as the run * length. Since the condition that caused truncated * write may be permanent, e.g. exhausted free space, * accepting n == 0 would cause an infinite loop. * * Forwarding the iterator leaves the unwritten page * behind, but there is not much we can do there if * filesystem refuses to write it. */ if (n == 0) { n = 1; allclean = FALSE; } } else { n = 1; vm_page_xunbusy(p); } np = vm_page_find_least(object, pi + n); } #if 0 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC) ? MNT_WAIT : 0); #endif /* * Leave updating cleangeneration for tmpfs objects to tmpfs * scan. It needs to update mtime, which happens for other * filesystems during page writeouts. */ if (allclean && object->type == OBJT_VNODE) object->cleangeneration = curgeneration; return (res); } static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags, int flags, boolean_t *allclean, boolean_t *eio) { vm_page_t ma[vm_pageout_page_count], p_first, tp; int count, i, mreq, runlen; vm_page_lock_assert(p, MA_NOTOWNED); vm_page_assert_xbusied(p); VM_OBJECT_ASSERT_WLOCKED(object); count = 1; mreq = 0; for (tp = p; count < vm_pageout_page_count; count++) { tp = vm_page_next(tp); if (tp == NULL || vm_page_tryxbusy(tp) == 0) break; if (!vm_object_page_remove_write(tp, flags, allclean)) { vm_page_xunbusy(tp); break; } } for (p_first = p; count < vm_pageout_page_count; count++) { tp = vm_page_prev(p_first); if (tp == NULL || vm_page_tryxbusy(tp) == 0) break; if (!vm_object_page_remove_write(tp, flags, allclean)) { vm_page_xunbusy(tp); break; } p_first = tp; mreq++; } for (tp = p_first, i = 0; i < count; tp = TAILQ_NEXT(tp, listq), i++) ma[i] = tp; vm_pageout_flush(ma, count, pagerflags, mreq, &runlen, eio); return (runlen); } /* * Note that there is absolutely no sense in writing out * anonymous objects, so we track down the vnode object * to write out. * We invalidate (remove) all pages from the address space * for semantic correctness. * * If the backing object is a device object with unmanaged pages, then any * mappings to the specified range of pages must be removed before this * function is called. * * Note: certain anonymous maps, such as MAP_NOSYNC maps, * may start out with a NULL object. */ boolean_t vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, boolean_t syncio, boolean_t invalidate) { vm_object_t backing_object; struct vnode *vp; struct mount *mp; int error, flags, fsync_after; boolean_t res; if (object == NULL) return (TRUE); res = TRUE; error = 0; VM_OBJECT_WLOCK(object); while ((backing_object = object->backing_object) != NULL) { VM_OBJECT_WLOCK(backing_object); offset += object->backing_object_offset; VM_OBJECT_WUNLOCK(object); object = backing_object; if (object->size < OFF_TO_IDX(offset + size)) size = IDX_TO_OFF(object->size) - offset; } /* * Flush pages if writing is allowed, invalidate them * if invalidation requested. Pages undergoing I/O * will be ignored by vm_object_page_remove(). * * We cannot lock the vnode and then wait for paging * to complete without deadlocking against vm_fault. * Instead we simply call vm_object_page_remove() and * allow it to block internally on a page-by-page * basis when it encounters pages undergoing async * I/O. */ if (object->type == OBJT_VNODE && vm_object_mightbedirty(object) != 0 && ((vp = object->handle)->v_vflag & VV_NOSYNC) == 0) { VM_OBJECT_WUNLOCK(object); (void)vn_start_write(vp, &mp, V_WAIT); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (syncio && !invalidate && offset == 0 && atop(size) == object->size) { /* * If syncing the whole mapping of the file, * it is faster to schedule all the writes in * async mode, also allowing the clustering, * and then wait for i/o to complete. */ flags = 0; fsync_after = TRUE; } else { flags = (syncio || invalidate) ? OBJPC_SYNC : 0; flags |= invalidate ? (OBJPC_SYNC | OBJPC_INVAL) : 0; fsync_after = FALSE; } VM_OBJECT_WLOCK(object); res = vm_object_page_clean(object, offset, offset + size, flags); VM_OBJECT_WUNLOCK(object); - if (fsync_after) - error = VOP_FSYNC(vp, MNT_WAIT, curthread); + if (fsync_after) { + for (;;) { + error = VOP_FSYNC(vp, MNT_WAIT, curthread); + if (error != ERELOOKUP) + break; + + /* + * Allow SU/bufdaemon to handle more + * dependencies in the meantime. + */ + VOP_UNLOCK(vp); + vn_finished_write(mp); + + (void)vn_start_write(vp, &mp, V_WAIT); + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); + } + } VOP_UNLOCK(vp); vn_finished_write(mp); if (error != 0) res = FALSE; VM_OBJECT_WLOCK(object); } if ((object->type == OBJT_VNODE || object->type == OBJT_DEVICE) && invalidate) { if (object->type == OBJT_DEVICE) /* * The option OBJPR_NOTMAPPED must be passed here * because vm_object_page_remove() cannot remove * unmanaged mappings. */ flags = OBJPR_NOTMAPPED; else if (old_msync) flags = 0; else flags = OBJPR_CLEANONLY; vm_object_page_remove(object, OFF_TO_IDX(offset), OFF_TO_IDX(offset + size + PAGE_MASK), flags); } VM_OBJECT_WUNLOCK(object); return (res); } /* * Determine whether the given advice can be applied to the object. Advice is * not applied to unmanaged pages since they never belong to page queues, and * since MADV_FREE is destructive, it can apply only to anonymous pages that * have been mapped at most once. */ static bool vm_object_advice_applies(vm_object_t object, int advice) { if ((object->flags & OBJ_UNMANAGED) != 0) return (false); if (advice != MADV_FREE) return (true); return ((object->flags & (OBJ_ONEMAPPING | OBJ_ANON)) == (OBJ_ONEMAPPING | OBJ_ANON)); } static void vm_object_madvise_freespace(vm_object_t object, int advice, vm_pindex_t pindex, vm_size_t size) { if (advice == MADV_FREE) vm_pager_freespace(object, pindex, size); } /* * vm_object_madvise: * * Implements the madvise function at the object/page level. * * MADV_WILLNEED (any object) * * Activate the specified pages if they are resident. * * MADV_DONTNEED (any object) * * Deactivate the specified pages if they are resident. * * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, * OBJ_ONEMAPPING only) * * Deactivate and clean the specified pages if they are * resident. This permits the process to reuse the pages * without faulting or the kernel to reclaim the pages * without I/O. */ void vm_object_madvise(vm_object_t object, vm_pindex_t pindex, vm_pindex_t end, int advice) { vm_pindex_t tpindex; vm_object_t backing_object, tobject; vm_page_t m, tm; if (object == NULL) return; relookup: VM_OBJECT_WLOCK(object); if (!vm_object_advice_applies(object, advice)) { VM_OBJECT_WUNLOCK(object); return; } for (m = vm_page_find_least(object, pindex); pindex < end; pindex++) { tobject = object; /* * If the next page isn't resident in the top-level object, we * need to search the shadow chain. When applying MADV_FREE, we * take care to release any swap space used to store * non-resident pages. */ if (m == NULL || pindex < m->pindex) { /* * Optimize a common case: if the top-level object has * no backing object, we can skip over the non-resident * range in constant time. */ if (object->backing_object == NULL) { tpindex = (m != NULL && m->pindex < end) ? m->pindex : end; vm_object_madvise_freespace(object, advice, pindex, tpindex - pindex); if ((pindex = tpindex) == end) break; goto next_page; } tpindex = pindex; do { vm_object_madvise_freespace(tobject, advice, tpindex, 1); /* * Prepare to search the next object in the * chain. */ backing_object = tobject->backing_object; if (backing_object == NULL) goto next_pindex; VM_OBJECT_WLOCK(backing_object); tpindex += OFF_TO_IDX(tobject->backing_object_offset); if (tobject != object) VM_OBJECT_WUNLOCK(tobject); tobject = backing_object; if (!vm_object_advice_applies(tobject, advice)) goto next_pindex; } while ((tm = vm_page_lookup(tobject, tpindex)) == NULL); } else { next_page: tm = m; m = TAILQ_NEXT(m, listq); } /* * If the page is not in a normal state, skip it. The page * can not be invalidated while the object lock is held. */ if (!vm_page_all_valid(tm) || vm_page_wired(tm)) goto next_pindex; KASSERT((tm->flags & PG_FICTITIOUS) == 0, ("vm_object_madvise: page %p is fictitious", tm)); KASSERT((tm->oflags & VPO_UNMANAGED) == 0, ("vm_object_madvise: page %p is not managed", tm)); if (vm_page_tryxbusy(tm) == 0) { if (object != tobject) VM_OBJECT_WUNLOCK(object); if (advice == MADV_WILLNEED) { /* * Reference the page before unlocking and * sleeping so that the page daemon is less * likely to reclaim it. */ vm_page_aflag_set(tm, PGA_REFERENCED); } if (!vm_page_busy_sleep(tm, "madvpo", 0)) VM_OBJECT_WUNLOCK(tobject); goto relookup; } vm_page_advise(tm, advice); vm_page_xunbusy(tm); vm_object_madvise_freespace(tobject, advice, tm->pindex, 1); next_pindex: if (tobject != object) VM_OBJECT_WUNLOCK(tobject); } VM_OBJECT_WUNLOCK(object); } /* * vm_object_shadow: * * Create a new object which is backed by the * specified existing object range. The source * object reference is deallocated. * * The new object and offset into that object * are returned in the source parameters. */ void vm_object_shadow(vm_object_t *object, vm_ooffset_t *offset, vm_size_t length, struct ucred *cred, bool shared) { vm_object_t source; vm_object_t result; source = *object; /* * Don't create the new object if the old object isn't shared. * * If we hold the only reference we can guarantee that it won't * increase while we have the map locked. Otherwise the race is * harmless and we will end up with an extra shadow object that * will be collapsed later. */ if (source != NULL && source->ref_count == 1 && (source->flags & OBJ_ANON) != 0) return; /* * Allocate a new object with the given length. */ result = vm_object_allocate_anon(atop(length), source, cred, length); /* * Store the offset into the source object, and fix up the offset into * the new object. */ result->backing_object_offset = *offset; if (shared || source != NULL) { VM_OBJECT_WLOCK(result); /* * The new object shadows the source object, adding a * reference to it. Our caller changes his reference * to point to the new object, removing a reference to * the source object. Net result: no change of * reference count, unless the caller needs to add one * more reference due to forking a shared map entry. */ if (shared) { vm_object_reference_locked(result); vm_object_clear_flag(result, OBJ_ONEMAPPING); } /* * Try to optimize the result object's page color when * shadowing in order to maintain page coloring * consistency in the combined shadowed object. */ if (source != NULL) { vm_object_backing_insert(result, source); result->domain = source->domain; #if VM_NRESERVLEVEL > 0 vm_object_set_flag(result, (source->flags & OBJ_COLORED)); result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & ((1 << (VM_NFREEORDER - 1)) - 1); #endif } VM_OBJECT_WUNLOCK(result); } /* * Return the new things */ *offset = 0; *object = result; } /* * vm_object_split: * * Split the pages in a map entry into a new object. This affords * easier removal of unused pages, and keeps object inheritance from * being a negative impact on memory usage. */ void vm_object_split(vm_map_entry_t entry) { vm_page_t m, m_busy, m_next; vm_object_t orig_object, new_object, backing_object; vm_pindex_t idx, offidxstart; vm_size_t size; orig_object = entry->object.vm_object; KASSERT((orig_object->flags & OBJ_ONEMAPPING) != 0, ("vm_object_split: Splitting object with multiple mappings.")); if ((orig_object->flags & OBJ_ANON) == 0) return; if (orig_object->ref_count <= 1) return; VM_OBJECT_WUNLOCK(orig_object); offidxstart = OFF_TO_IDX(entry->offset); size = atop(entry->end - entry->start); /* * If swap_pager_copy() is later called, it will convert new_object * into a swap object. */ new_object = vm_object_allocate_anon(size, orig_object, orig_object->cred, ptoa(size)); /* * We must wait for the orig_object to complete any in-progress * collapse so that the swap blocks are stable below. The * additional reference on backing_object by new object will * prevent further collapse operations until split completes. */ VM_OBJECT_WLOCK(orig_object); vm_object_collapse_wait(orig_object); /* * At this point, the new object is still private, so the order in * which the original and new objects are locked does not matter. */ VM_OBJECT_WLOCK(new_object); new_object->domain = orig_object->domain; backing_object = orig_object->backing_object; if (backing_object != NULL) { vm_object_backing_insert_ref(new_object, backing_object); new_object->backing_object_offset = orig_object->backing_object_offset + entry->offset; } if (orig_object->cred != NULL) { crhold(orig_object->cred); KASSERT(orig_object->charge >= ptoa(size), ("orig_object->charge < 0")); orig_object->charge -= ptoa(size); } /* * Mark the split operation so that swap_pager_getpages() knows * that the object is in transition. */ vm_object_set_flag(orig_object, OBJ_SPLIT); m_busy = NULL; #ifdef INVARIANTS idx = 0; #endif retry: m = vm_page_find_least(orig_object, offidxstart); KASSERT(m == NULL || idx <= m->pindex - offidxstart, ("%s: object %p was repopulated", __func__, orig_object)); for (; m != NULL && (idx = m->pindex - offidxstart) < size; m = m_next) { m_next = TAILQ_NEXT(m, listq); /* * We must wait for pending I/O to complete before we can * rename the page. * * We do not have to VM_PROT_NONE the page as mappings should * not be changed by this operation. */ if (vm_page_tryxbusy(m) == 0) { VM_OBJECT_WUNLOCK(new_object); if (vm_page_busy_sleep(m, "spltwt", 0)) VM_OBJECT_WLOCK(orig_object); VM_OBJECT_WLOCK(new_object); goto retry; } /* * The page was left invalid. Likely placed there by * an incomplete fault. Just remove and ignore. */ if (vm_page_none_valid(m)) { if (vm_page_remove(m)) vm_page_free(m); continue; } /* vm_page_rename() will dirty the page. */ if (vm_page_rename(m, new_object, idx)) { vm_page_xunbusy(m); VM_OBJECT_WUNLOCK(new_object); VM_OBJECT_WUNLOCK(orig_object); vm_radix_wait(); VM_OBJECT_WLOCK(orig_object); VM_OBJECT_WLOCK(new_object); goto retry; } #if VM_NRESERVLEVEL > 0 /* * If some of the reservation's allocated pages remain with * the original object, then transferring the reservation to * the new object is neither particularly beneficial nor * particularly harmful as compared to leaving the reservation * with the original object. If, however, all of the * reservation's allocated pages are transferred to the new * object, then transferring the reservation is typically * beneficial. Determining which of these two cases applies * would be more costly than unconditionally renaming the * reservation. */ vm_reserv_rename(m, new_object, orig_object, offidxstart); #endif /* * orig_object's type may change while sleeping, so keep track * of the beginning of the busied range. */ if (orig_object->type != OBJT_SWAP) vm_page_xunbusy(m); else if (m_busy == NULL) m_busy = m; } if ((orig_object->flags & OBJ_SWAP) != 0) { /* * swap_pager_copy() can sleep, in which case the orig_object's * and new_object's locks are released and reacquired. */ swap_pager_copy(orig_object, new_object, offidxstart, 0); if (m_busy != NULL) TAILQ_FOREACH_FROM(m_busy, &new_object->memq, listq) vm_page_xunbusy(m_busy); } vm_object_clear_flag(orig_object, OBJ_SPLIT); VM_OBJECT_WUNLOCK(orig_object); VM_OBJECT_WUNLOCK(new_object); entry->object.vm_object = new_object; entry->offset = 0LL; vm_object_deallocate(orig_object); VM_OBJECT_WLOCK(new_object); } static vm_page_t vm_object_collapse_scan_wait(vm_object_t object, vm_page_t p) { vm_object_t backing_object; VM_OBJECT_ASSERT_WLOCKED(object); backing_object = object->backing_object; VM_OBJECT_ASSERT_WLOCKED(backing_object); KASSERT(p == NULL || p->object == object || p->object == backing_object, ("invalid ownership %p %p %p", p, object, backing_object)); /* The page is only NULL when rename fails. */ if (p == NULL) { VM_OBJECT_WUNLOCK(object); VM_OBJECT_WUNLOCK(backing_object); vm_radix_wait(); VM_OBJECT_WLOCK(object); } else if (p->object == object) { VM_OBJECT_WUNLOCK(backing_object); if (vm_page_busy_sleep(p, "vmocol", 0)) VM_OBJECT_WLOCK(object); } else { VM_OBJECT_WUNLOCK(object); if (!vm_page_busy_sleep(p, "vmocol", 0)) VM_OBJECT_WUNLOCK(backing_object); VM_OBJECT_WLOCK(object); } VM_OBJECT_WLOCK(backing_object); return (TAILQ_FIRST(&backing_object->memq)); } static bool vm_object_scan_all_shadowed(vm_object_t object) { vm_object_t backing_object; vm_page_t p, pp; vm_pindex_t backing_offset_index, new_pindex, pi, ps; VM_OBJECT_ASSERT_WLOCKED(object); VM_OBJECT_ASSERT_WLOCKED(object->backing_object); backing_object = object->backing_object; if ((backing_object->flags & OBJ_ANON) == 0) return (false); pi = backing_offset_index = OFF_TO_IDX(object->backing_object_offset); p = vm_page_find_least(backing_object, pi); ps = swap_pager_find_least(backing_object, pi); /* * Only check pages inside the parent object's range and * inside the parent object's mapping of the backing object. */ for (;; pi++) { if (p != NULL && p->pindex < pi) p = TAILQ_NEXT(p, listq); if (ps < pi) ps = swap_pager_find_least(backing_object, pi); if (p == NULL && ps >= backing_object->size) break; else if (p == NULL) pi = ps; else pi = MIN(p->pindex, ps); new_pindex = pi - backing_offset_index; if (new_pindex >= object->size) break; if (p != NULL) { /* * If the backing object page is busy a * grandparent or older page may still be * undergoing CoW. It is not safe to collapse * the backing object until it is quiesced. */ if (vm_page_tryxbusy(p) == 0) return (false); /* * We raced with the fault handler that left * newly allocated invalid page on the object * queue and retried. */ if (!vm_page_all_valid(p)) goto unbusy_ret; } /* * See if the parent has the page or if the parent's object * pager has the page. If the parent has the page but the page * is not valid, the parent's object pager must have the page. * * If this fails, the parent does not completely shadow the * object and we might as well give up now. */ pp = vm_page_lookup(object, new_pindex); /* * The valid check here is stable due to object lock * being required to clear valid and initiate paging. * Busy of p disallows fault handler to validate pp. */ if ((pp == NULL || vm_page_none_valid(pp)) && !vm_pager_has_page(object, new_pindex, NULL, NULL)) goto unbusy_ret; if (p != NULL) vm_page_xunbusy(p); } return (true); unbusy_ret: if (p != NULL) vm_page_xunbusy(p); return (false); } static void vm_object_collapse_scan(vm_object_t object) { vm_object_t backing_object; vm_page_t next, p, pp; vm_pindex_t backing_offset_index, new_pindex; VM_OBJECT_ASSERT_WLOCKED(object); VM_OBJECT_ASSERT_WLOCKED(object->backing_object); backing_object = object->backing_object; backing_offset_index = OFF_TO_IDX(object->backing_object_offset); /* * Our scan */ for (p = TAILQ_FIRST(&backing_object->memq); p != NULL; p = next) { next = TAILQ_NEXT(p, listq); new_pindex = p->pindex - backing_offset_index; /* * Check for busy page */ if (vm_page_tryxbusy(p) == 0) { next = vm_object_collapse_scan_wait(object, p); continue; } KASSERT(object->backing_object == backing_object, ("vm_object_collapse_scan: backing object mismatch %p != %p", object->backing_object, backing_object)); KASSERT(p->object == backing_object, ("vm_object_collapse_scan: object mismatch %p != %p", p->object, backing_object)); if (p->pindex < backing_offset_index || new_pindex >= object->size) { vm_pager_freespace(backing_object, p->pindex, 1); KASSERT(!pmap_page_is_mapped(p), ("freeing mapped page %p", p)); if (vm_page_remove(p)) vm_page_free(p); continue; } if (!vm_page_all_valid(p)) { KASSERT(!pmap_page_is_mapped(p), ("freeing mapped page %p", p)); if (vm_page_remove(p)) vm_page_free(p); continue; } pp = vm_page_lookup(object, new_pindex); if (pp != NULL && vm_page_tryxbusy(pp) == 0) { vm_page_xunbusy(p); /* * The page in the parent is busy and possibly not * (yet) valid. Until its state is finalized by the * busy bit owner, we can't tell whether it shadows the * original page. */ next = vm_object_collapse_scan_wait(object, pp); continue; } if (pp != NULL && vm_page_none_valid(pp)) { /* * The page was invalid in the parent. Likely placed * there by an incomplete fault. Just remove and * ignore. p can replace it. */ if (vm_page_remove(pp)) vm_page_free(pp); pp = NULL; } if (pp != NULL || vm_pager_has_page(object, new_pindex, NULL, NULL)) { /* * The page already exists in the parent OR swap exists * for this location in the parent. Leave the parent's * page alone. Destroy the original page from the * backing object. */ vm_pager_freespace(backing_object, p->pindex, 1); KASSERT(!pmap_page_is_mapped(p), ("freeing mapped page %p", p)); if (vm_page_remove(p)) vm_page_free(p); if (pp != NULL) vm_page_xunbusy(pp); continue; } /* * Page does not exist in parent, rename the page from the * backing object to the main object. * * If the page was mapped to a process, it can remain mapped * through the rename. vm_page_rename() will dirty the page. */ if (vm_page_rename(p, object, new_pindex)) { vm_page_xunbusy(p); next = vm_object_collapse_scan_wait(object, NULL); continue; } /* Use the old pindex to free the right page. */ vm_pager_freespace(backing_object, new_pindex + backing_offset_index, 1); #if VM_NRESERVLEVEL > 0 /* * Rename the reservation. */ vm_reserv_rename(p, object, backing_object, backing_offset_index); #endif vm_page_xunbusy(p); } return; } /* * vm_object_collapse: * * Collapse an object with the object backing it. * Pages in the backing object are moved into the * parent, and the backing object is deallocated. */ void vm_object_collapse(vm_object_t object) { vm_object_t backing_object, new_backing_object; VM_OBJECT_ASSERT_WLOCKED(object); while (TRUE) { KASSERT((object->flags & (OBJ_DEAD | OBJ_ANON)) == OBJ_ANON, ("collapsing invalid object")); /* * Wait for the backing_object to finish any pending * collapse so that the caller sees the shortest possible * shadow chain. */ backing_object = vm_object_backing_collapse_wait(object); if (backing_object == NULL) return; KASSERT(object->ref_count > 0 && object->ref_count > atomic_load_int(&object->shadow_count), ("collapse with invalid ref %d or shadow %d count.", object->ref_count, atomic_load_int(&object->shadow_count))); KASSERT((backing_object->flags & (OBJ_COLLAPSING | OBJ_DEAD)) == 0, ("vm_object_collapse: Backing object already collapsing.")); KASSERT((object->flags & (OBJ_COLLAPSING | OBJ_DEAD)) == 0, ("vm_object_collapse: object is already collapsing.")); /* * We know that we can either collapse the backing object if * the parent is the only reference to it, or (perhaps) have * the parent bypass the object if the parent happens to shadow * all the resident pages in the entire backing object. */ if (backing_object->ref_count == 1) { KASSERT(atomic_load_int(&backing_object->shadow_count) == 1, ("vm_object_collapse: shadow_count: %d", atomic_load_int(&backing_object->shadow_count))); vm_object_pip_add(object, 1); vm_object_set_flag(object, OBJ_COLLAPSING); vm_object_pip_add(backing_object, 1); vm_object_set_flag(backing_object, OBJ_DEAD); /* * If there is exactly one reference to the backing * object, we can collapse it into the parent. */ vm_object_collapse_scan(object); #if VM_NRESERVLEVEL > 0 /* * Break any reservations from backing_object. */ if (__predict_false(!LIST_EMPTY(&backing_object->rvq))) vm_reserv_break_all(backing_object); #endif /* * Move the pager from backing_object to object. */ if ((backing_object->flags & OBJ_SWAP) != 0) { /* * swap_pager_copy() can sleep, in which case * the backing_object's and object's locks are * released and reacquired. * Since swap_pager_copy() is being asked to * destroy backing_object, it will change the * type to OBJT_DEFAULT. */ swap_pager_copy( backing_object, object, OFF_TO_IDX(object->backing_object_offset), TRUE); } /* * Object now shadows whatever backing_object did. */ vm_object_clear_flag(object, OBJ_COLLAPSING); vm_object_backing_transfer(object, backing_object); object->backing_object_offset += backing_object->backing_object_offset; VM_OBJECT_WUNLOCK(object); vm_object_pip_wakeup(object); /* * Discard backing_object. * * Since the backing object has no pages, no pager left, * and no object references within it, all that is * necessary is to dispose of it. */ KASSERT(backing_object->ref_count == 1, ( "backing_object %p was somehow re-referenced during collapse!", backing_object)); vm_object_pip_wakeup(backing_object); (void)refcount_release(&backing_object->ref_count); vm_object_terminate(backing_object); counter_u64_add(object_collapses, 1); VM_OBJECT_WLOCK(object); } else { /* * If we do not entirely shadow the backing object, * there is nothing we can do so we give up. * * The object lock and backing_object lock must not * be dropped during this sequence. */ if (!vm_object_scan_all_shadowed(object)) { VM_OBJECT_WUNLOCK(backing_object); break; } /* * Make the parent shadow the next object in the * chain. Deallocating backing_object will not remove * it, since its reference count is at least 2. */ vm_object_backing_remove_locked(object); new_backing_object = backing_object->backing_object; if (new_backing_object != NULL) { vm_object_backing_insert_ref(object, new_backing_object); object->backing_object_offset += backing_object->backing_object_offset; } /* * Drop the reference count on backing_object. Since * its ref_count was at least 2, it will not vanish. */ (void)refcount_release(&backing_object->ref_count); KASSERT(backing_object->ref_count >= 1, ( "backing_object %p was somehow dereferenced during collapse!", backing_object)); VM_OBJECT_WUNLOCK(backing_object); counter_u64_add(object_bypasses, 1); } /* * Try again with this object's new backing object. */ } } /* * vm_object_page_remove: * * For the given object, either frees or invalidates each of the * specified pages. In general, a page is freed. However, if a page is * wired for any reason other than the existence of a managed, wired * mapping, then it may be invalidated but not removed from the object. * Pages are specified by the given range ["start", "end") and the option * OBJPR_CLEANONLY. As a special case, if "end" is zero, then the range * extends from "start" to the end of the object. If the option * OBJPR_CLEANONLY is specified, then only the non-dirty pages within the * specified range are affected. If the option OBJPR_NOTMAPPED is * specified, then the pages within the specified range must have no * mappings. Otherwise, if this option is not specified, any mappings to * the specified pages are removed before the pages are freed or * invalidated. * * In general, this operation should only be performed on objects that * contain managed pages. There are, however, two exceptions. First, it * is performed on the kernel and kmem objects by vm_map_entry_delete(). * Second, it is used by msync(..., MS_INVALIDATE) to invalidate device- * backed pages. In both of these cases, the option OBJPR_CLEANONLY must * not be specified and the option OBJPR_NOTMAPPED must be specified. * * The object must be locked. */ void vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int options) { vm_page_t p, next; VM_OBJECT_ASSERT_WLOCKED(object); KASSERT((object->flags & OBJ_UNMANAGED) == 0 || (options & (OBJPR_CLEANONLY | OBJPR_NOTMAPPED)) == OBJPR_NOTMAPPED, ("vm_object_page_remove: illegal options for object %p", object)); if (object->resident_page_count == 0) return; vm_object_pip_add(object, 1); again: p = vm_page_find_least(object, start); /* * Here, the variable "p" is either (1) the page with the least pindex * greater than or equal to the parameter "start" or (2) NULL. */ for (; p != NULL && (p->pindex < end || end == 0); p = next) { next = TAILQ_NEXT(p, listq); /* * Skip invalid pages if asked to do so. Try to avoid acquiring * the busy lock, as some consumers rely on this to avoid * deadlocks. * * A thread may concurrently transition the page from invalid to * valid using only the busy lock, so the result of this check * is immediately stale. It is up to consumers to handle this, * for instance by ensuring that all invalid->valid transitions * happen with a mutex held, as may be possible for a * filesystem. */ if ((options & OBJPR_VALIDONLY) != 0 && vm_page_none_valid(p)) continue; /* * If the page is wired for any reason besides the existence * of managed, wired mappings, then it cannot be freed. For * example, fictitious pages, which represent device memory, * are inherently wired and cannot be freed. They can, * however, be invalidated if the option OBJPR_CLEANONLY is * not specified. */ if (vm_page_tryxbusy(p) == 0) { if (vm_page_busy_sleep(p, "vmopar", 0)) VM_OBJECT_WLOCK(object); goto again; } if ((options & OBJPR_VALIDONLY) != 0 && vm_page_none_valid(p)) { vm_page_xunbusy(p); continue; } if (vm_page_wired(p)) { wired: if ((options & OBJPR_NOTMAPPED) == 0 && object->ref_count != 0) pmap_remove_all(p); if ((options & OBJPR_CLEANONLY) == 0) { vm_page_invalid(p); vm_page_undirty(p); } vm_page_xunbusy(p); continue; } KASSERT((p->flags & PG_FICTITIOUS) == 0, ("vm_object_page_remove: page %p is fictitious", p)); if ((options & OBJPR_CLEANONLY) != 0 && !vm_page_none_valid(p)) { if ((options & OBJPR_NOTMAPPED) == 0 && object->ref_count != 0 && !vm_page_try_remove_write(p)) goto wired; if (p->dirty != 0) { vm_page_xunbusy(p); continue; } } if ((options & OBJPR_NOTMAPPED) == 0 && object->ref_count != 0 && !vm_page_try_remove_all(p)) goto wired; vm_page_free(p); } vm_object_pip_wakeup(object); vm_pager_freespace(object, start, (end == 0 ? object->size : end) - start); } /* * vm_object_page_noreuse: * * For the given object, attempt to move the specified pages to * the head of the inactive queue. This bypasses regular LRU * operation and allows the pages to be reused quickly under memory * pressure. If a page is wired for any reason, then it will not * be queued. Pages are specified by the range ["start", "end"). * As a special case, if "end" is zero, then the range extends from * "start" to the end of the object. * * This operation should only be performed on objects that * contain non-fictitious, managed pages. * * The object must be locked. */ void vm_object_page_noreuse(vm_object_t object, vm_pindex_t start, vm_pindex_t end) { vm_page_t p, next; VM_OBJECT_ASSERT_LOCKED(object); KASSERT((object->flags & (OBJ_FICTITIOUS | OBJ_UNMANAGED)) == 0, ("vm_object_page_noreuse: illegal object %p", object)); if (object->resident_page_count == 0) return; p = vm_page_find_least(object, start); /* * Here, the variable "p" is either (1) the page with the least pindex * greater than or equal to the parameter "start" or (2) NULL. */ for (; p != NULL && (p->pindex < end || end == 0); p = next) { next = TAILQ_NEXT(p, listq); vm_page_deactivate_noreuse(p); } } /* * Populate the specified range of the object with valid pages. Returns * TRUE if the range is successfully populated and FALSE otherwise. * * Note: This function should be optimized to pass a larger array of * pages to vm_pager_get_pages() before it is applied to a non- * OBJT_DEVICE object. * * The object must be locked. */ boolean_t vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end) { vm_page_t m; vm_pindex_t pindex; int rv; VM_OBJECT_ASSERT_WLOCKED(object); for (pindex = start; pindex < end; pindex++) { rv = vm_page_grab_valid(&m, object, pindex, VM_ALLOC_NORMAL); if (rv != VM_PAGER_OK) break; /* * Keep "m" busy because a subsequent iteration may unlock * the object. */ } if (pindex > start) { m = vm_page_lookup(object, start); while (m != NULL && m->pindex < pindex) { vm_page_xunbusy(m); m = TAILQ_NEXT(m, listq); } } return (pindex == end); } /* * Routine: vm_object_coalesce * Function: Coalesces two objects backing up adjoining * regions of memory into a single object. * * returns TRUE if objects were combined. * * NOTE: Only works at the moment if the second object is NULL - * if it's not, which object do we lock first? * * Parameters: * prev_object First object to coalesce * prev_offset Offset into prev_object * prev_size Size of reference to prev_object * next_size Size of reference to the second object * reserved Indicator that extension region has * swap accounted for * * Conditions: * The object must *not* be locked. */ boolean_t vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, vm_size_t prev_size, vm_size_t next_size, boolean_t reserved) { vm_pindex_t next_pindex; if (prev_object == NULL) return (TRUE); if ((prev_object->flags & OBJ_ANON) == 0) return (FALSE); VM_OBJECT_WLOCK(prev_object); /* * Try to collapse the object first. */ vm_object_collapse(prev_object); /* * Can't coalesce if: . more than one reference . paged out . shadows * another object . has a copy elsewhere (any of which mean that the * pages not mapped to prev_entry may be in use anyway) */ if (prev_object->backing_object != NULL) { VM_OBJECT_WUNLOCK(prev_object); return (FALSE); } prev_size >>= PAGE_SHIFT; next_size >>= PAGE_SHIFT; next_pindex = OFF_TO_IDX(prev_offset) + prev_size; if (prev_object->ref_count > 1 && prev_object->size != next_pindex && (prev_object->flags & OBJ_ONEMAPPING) == 0) { VM_OBJECT_WUNLOCK(prev_object); return (FALSE); } /* * Account for the charge. */ if (prev_object->cred != NULL) { /* * If prev_object was charged, then this mapping, * although not charged now, may become writable * later. Non-NULL cred in the object would prevent * swap reservation during enabling of the write * access, so reserve swap now. Failed reservation * cause allocation of the separate object for the map * entry, and swap reservation for this entry is * managed in appropriate time. */ if (!reserved && !swap_reserve_by_cred(ptoa(next_size), prev_object->cred)) { VM_OBJECT_WUNLOCK(prev_object); return (FALSE); } prev_object->charge += ptoa(next_size); } /* * Remove any pages that may still be in the object from a previous * deallocation. */ if (next_pindex < prev_object->size) { vm_object_page_remove(prev_object, next_pindex, next_pindex + next_size, 0); #if 0 if (prev_object->cred != NULL) { KASSERT(prev_object->charge >= ptoa(prev_object->size - next_pindex), ("object %p overcharged 1 %jx %jx", prev_object, (uintmax_t)next_pindex, (uintmax_t)next_size)); prev_object->charge -= ptoa(prev_object->size - next_pindex); } #endif } /* * Extend the object if necessary. */ if (next_pindex + next_size > prev_object->size) prev_object->size = next_pindex + next_size; VM_OBJECT_WUNLOCK(prev_object); return (TRUE); } void vm_object_set_writeable_dirty_(vm_object_t object) { atomic_add_int(&object->generation, 1); } bool vm_object_mightbedirty_(vm_object_t object) { return (object->generation != object->cleangeneration); } /* * vm_object_unwire: * * For each page offset within the specified range of the given object, * find the highest-level page in the shadow chain and unwire it. A page * must exist at every page offset, and the highest-level page must be * wired. */ void vm_object_unwire(vm_object_t object, vm_ooffset_t offset, vm_size_t length, uint8_t queue) { vm_object_t tobject, t1object; vm_page_t m, tm; vm_pindex_t end_pindex, pindex, tpindex; int depth, locked_depth; KASSERT((offset & PAGE_MASK) == 0, ("vm_object_unwire: offset is not page aligned")); KASSERT((length & PAGE_MASK) == 0, ("vm_object_unwire: length is not a multiple of PAGE_SIZE")); /* The wired count of a fictitious page never changes. */ if ((object->flags & OBJ_FICTITIOUS) != 0) return; pindex = OFF_TO_IDX(offset); end_pindex = pindex + atop(length); again: locked_depth = 1; VM_OBJECT_RLOCK(object); m = vm_page_find_least(object, pindex); while (pindex < end_pindex) { if (m == NULL || pindex < m->pindex) { /* * The first object in the shadow chain doesn't * contain a page at the current index. Therefore, * the page must exist in a backing object. */ tobject = object; tpindex = pindex; depth = 0; do { tpindex += OFF_TO_IDX(tobject->backing_object_offset); tobject = tobject->backing_object; KASSERT(tobject != NULL, ("vm_object_unwire: missing page")); if ((tobject->flags & OBJ_FICTITIOUS) != 0) goto next_page; depth++; if (depth == locked_depth) { locked_depth++; VM_OBJECT_RLOCK(tobject); } } while ((tm = vm_page_lookup(tobject, tpindex)) == NULL); } else { tm = m; m = TAILQ_NEXT(m, listq); } if (vm_page_trysbusy(tm) == 0) { for (tobject = object; locked_depth >= 1; locked_depth--) { t1object = tobject->backing_object; if (tm->object != tobject) VM_OBJECT_RUNLOCK(tobject); tobject = t1object; } tobject = tm->object; if (!vm_page_busy_sleep(tm, "unwbo", VM_ALLOC_IGN_SBUSY)) VM_OBJECT_RUNLOCK(tobject); goto again; } vm_page_unwire(tm, queue); vm_page_sunbusy(tm); next_page: pindex++; } /* Release the accumulated object locks. */ for (tobject = object; locked_depth >= 1; locked_depth--) { t1object = tobject->backing_object; VM_OBJECT_RUNLOCK(tobject); tobject = t1object; } } /* * Return the vnode for the given object, or NULL if none exists. * For tmpfs objects, the function may return NULL if there is * no vnode allocated at the time of the call. */ struct vnode * vm_object_vnode(vm_object_t object) { struct vnode *vp; VM_OBJECT_ASSERT_LOCKED(object); vm_pager_getvp(object, &vp, NULL); return (vp); } /* * Busy the vm object. This prevents new pages belonging to the object from * becoming busy. Existing pages persist as busy. Callers are responsible * for checking page state before proceeding. */ void vm_object_busy(vm_object_t obj) { VM_OBJECT_ASSERT_LOCKED(obj); blockcount_acquire(&obj->busy, 1); /* The fence is required to order loads of page busy. */ atomic_thread_fence_acq_rel(); } void vm_object_unbusy(vm_object_t obj) { blockcount_release(&obj->busy, 1); } void vm_object_busy_wait(vm_object_t obj, const char *wmesg) { VM_OBJECT_ASSERT_UNLOCKED(obj); (void)blockcount_sleep(&obj->busy, NULL, wmesg, PVM); } /* * This function aims to determine if the object is mapped, * specifically, if it is referenced by a vm_map_entry. Because * objects occasionally acquire transient references that do not * represent a mapping, the method used here is inexact. However, it * has very low overhead and is good enough for the advisory * vm.vmtotal sysctl. */ bool vm_object_is_active(vm_object_t obj) { return (obj->ref_count > atomic_load_int(&obj->shadow_count)); } static int vm_object_list_handler(struct sysctl_req *req, bool swap_only) { struct kinfo_vmobject *kvo; char *fullpath, *freepath; struct vnode *vp; struct vattr va; vm_object_t obj; vm_page_t m; u_long sp; int count, error; if (req->oldptr == NULL) { /* * If an old buffer has not been provided, generate an * estimate of the space needed for a subsequent call. */ mtx_lock(&vm_object_list_mtx); count = 0; TAILQ_FOREACH(obj, &vm_object_list, object_list) { if (obj->type == OBJT_DEAD) continue; count++; } mtx_unlock(&vm_object_list_mtx); return (SYSCTL_OUT(req, NULL, sizeof(struct kinfo_vmobject) * count * 11 / 10)); } kvo = malloc(sizeof(*kvo), M_TEMP, M_WAITOK); error = 0; /* * VM objects are type stable and are never removed from the * list once added. This allows us to safely read obj->object_list * after reacquiring the VM object lock. */ mtx_lock(&vm_object_list_mtx); TAILQ_FOREACH(obj, &vm_object_list, object_list) { if (obj->type == OBJT_DEAD || (swap_only && (obj->flags & (OBJ_ANON | OBJ_SWAP)) == 0)) continue; VM_OBJECT_RLOCK(obj); if (obj->type == OBJT_DEAD || (swap_only && (obj->flags & (OBJ_ANON | OBJ_SWAP)) == 0)) { VM_OBJECT_RUNLOCK(obj); continue; } mtx_unlock(&vm_object_list_mtx); kvo->kvo_size = ptoa(obj->size); kvo->kvo_resident = obj->resident_page_count; kvo->kvo_ref_count = obj->ref_count; kvo->kvo_shadow_count = atomic_load_int(&obj->shadow_count); kvo->kvo_memattr = obj->memattr; kvo->kvo_active = 0; kvo->kvo_inactive = 0; if (!swap_only) { TAILQ_FOREACH(m, &obj->memq, listq) { /* * A page may belong to the object but be * dequeued and set to PQ_NONE while the * object lock is not held. This makes the * reads of m->queue below racy, and we do not * count pages set to PQ_NONE. However, this * sysctl is only meant to give an * approximation of the system anyway. */ if (m->a.queue == PQ_ACTIVE) kvo->kvo_active++; else if (m->a.queue == PQ_INACTIVE) kvo->kvo_inactive++; } } kvo->kvo_vn_fileid = 0; kvo->kvo_vn_fsid = 0; kvo->kvo_vn_fsid_freebsd11 = 0; freepath = NULL; fullpath = ""; vp = NULL; kvo->kvo_type = vm_object_kvme_type(obj, swap_only ? NULL : &vp); if (vp != NULL) { vref(vp); } else if ((obj->flags & OBJ_ANON) != 0) { MPASS(kvo->kvo_type == KVME_TYPE_DEFAULT || kvo->kvo_type == KVME_TYPE_SWAP); kvo->kvo_me = (uintptr_t)obj; /* tmpfs objs are reported as vnodes */ kvo->kvo_backing_obj = (uintptr_t)obj->backing_object; sp = swap_pager_swapped_pages(obj); kvo->kvo_swapped = sp > UINT32_MAX ? UINT32_MAX : sp; } VM_OBJECT_RUNLOCK(obj); if (vp != NULL) { vn_fullpath(vp, &fullpath, &freepath); vn_lock(vp, LK_SHARED | LK_RETRY); if (VOP_GETATTR(vp, &va, curthread->td_ucred) == 0) { kvo->kvo_vn_fileid = va.va_fileid; kvo->kvo_vn_fsid = va.va_fsid; kvo->kvo_vn_fsid_freebsd11 = va.va_fsid; /* truncate */ } vput(vp); } strlcpy(kvo->kvo_path, fullpath, sizeof(kvo->kvo_path)); if (freepath != NULL) free(freepath, M_TEMP); /* Pack record size down */ kvo->kvo_structsize = offsetof(struct kinfo_vmobject, kvo_path) + strlen(kvo->kvo_path) + 1; kvo->kvo_structsize = roundup(kvo->kvo_structsize, sizeof(uint64_t)); error = SYSCTL_OUT(req, kvo, kvo->kvo_structsize); maybe_yield(); mtx_lock(&vm_object_list_mtx); if (error) break; } mtx_unlock(&vm_object_list_mtx); free(kvo, M_TEMP); return (error); } static int sysctl_vm_object_list(SYSCTL_HANDLER_ARGS) { return (vm_object_list_handler(req, false)); } SYSCTL_PROC(_vm, OID_AUTO, objects, CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP | CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_object_list, "S,kinfo_vmobject", "List of VM objects"); static int sysctl_vm_object_list_swap(SYSCTL_HANDLER_ARGS) { return (vm_object_list_handler(req, true)); } /* * This sysctl returns list of the anonymous or swap objects. Intent * is to provide stripped optimized list useful to analyze swap use. * Since technically non-swap (default) objects participate in the * shadow chains, and are converted to swap type as needed by swap * pager, we must report them. */ SYSCTL_PROC(_vm, OID_AUTO, swap_objects, CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP | CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_object_list_swap, "S,kinfo_vmobject", "List of swap VM objects"); #include "opt_ddb.h" #ifdef DDB #include #include #include static int _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) { vm_map_t tmpm; vm_map_entry_t tmpe; vm_object_t obj; if (map == 0) return 0; if (entry == 0) { VM_MAP_ENTRY_FOREACH(tmpe, map) { if (_vm_object_in_map(map, object, tmpe)) { return 1; } } } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { tmpm = entry->object.sub_map; VM_MAP_ENTRY_FOREACH(tmpe, tmpm) { if (_vm_object_in_map(tmpm, object, tmpe)) { return 1; } } } else if ((obj = entry->object.vm_object) != NULL) { for (; obj; obj = obj->backing_object) if (obj == object) { return 1; } } return 0; } static int vm_object_in_map(vm_object_t object) { struct proc *p; /* sx_slock(&allproc_lock); */ FOREACH_PROC_IN_SYSTEM(p) { if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) continue; if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { /* sx_sunlock(&allproc_lock); */ return 1; } } /* sx_sunlock(&allproc_lock); */ if (_vm_object_in_map(kernel_map, object, 0)) return 1; return 0; } DB_SHOW_COMMAND(vmochk, vm_object_check) { vm_object_t object; /* * make sure that internal objs are in a map somewhere * and none have zero ref counts. */ TAILQ_FOREACH(object, &vm_object_list, object_list) { if ((object->flags & OBJ_ANON) != 0) { if (object->ref_count == 0) { db_printf("vmochk: internal obj has zero ref count: %ld\n", (long)object->size); } if (!vm_object_in_map(object)) { db_printf( "vmochk: internal obj is not in a map: " "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", object->ref_count, (u_long)object->size, (u_long)object->size, (void *)object->backing_object); } } if (db_pager_quit) return; } } /* * vm_object_print: [ debug ] */ DB_SHOW_COMMAND(object, vm_object_print_static) { /* XXX convert args. */ vm_object_t object = (vm_object_t)addr; boolean_t full = have_addr; vm_page_t p; /* XXX count is an (unused) arg. Avoid shadowing it. */ #define count was_count int count; if (object == NULL) return; db_iprintf( "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x ruid %d charge %jx\n", object, (int)object->type, (uintmax_t)object->size, object->resident_page_count, object->ref_count, object->flags, object->cred ? object->cred->cr_ruid : -1, (uintmax_t)object->charge); db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", atomic_load_int(&object->shadow_count), object->backing_object ? object->backing_object->ref_count : 0, object->backing_object, (uintmax_t)object->backing_object_offset); if (!full) return; db_indent += 2; count = 0; TAILQ_FOREACH(p, &object->memq, listq) { if (count == 0) db_iprintf("memory:="); else if (count == 6) { db_printf("\n"); db_iprintf(" ..."); count = 0; } else db_printf(","); count++; db_printf("(off=0x%jx,page=0x%jx)", (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); if (db_pager_quit) break; } if (count != 0) db_printf("\n"); db_indent -= 2; } /* XXX. */ #undef count /* XXX need this non-static entry for calling from vm_map_print. */ void vm_object_print( /* db_expr_t */ long addr, boolean_t have_addr, /* db_expr_t */ long count, char *modif) { vm_object_print_static(addr, have_addr, count, modif); } DB_SHOW_COMMAND(vmopag, vm_object_print_pages) { vm_object_t object; vm_pindex_t fidx; vm_paddr_t pa; vm_page_t m, prev_m; int rcount; TAILQ_FOREACH(object, &vm_object_list, object_list) { db_printf("new object: %p\n", (void *)object); if (db_pager_quit) return; rcount = 0; fidx = 0; pa = -1; TAILQ_FOREACH(m, &object->memq, listq) { if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL && prev_m->pindex + 1 != m->pindex) { if (rcount) { db_printf(" index(%ld)run(%d)pa(0x%lx)\n", (long)fidx, rcount, (long)pa); if (db_pager_quit) return; rcount = 0; } } if (rcount && (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { ++rcount; continue; } if (rcount) { db_printf(" index(%ld)run(%d)pa(0x%lx)\n", (long)fidx, rcount, (long)pa); if (db_pager_quit) return; } fidx = m->pindex; pa = VM_PAGE_TO_PHYS(m); rcount = 1; } if (rcount) { db_printf(" index(%ld)run(%d)pa(0x%lx)\n", (long)fidx, rcount, (long)pa); if (db_pager_quit) return; } } } #endif /* DDB */