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Index: sys/fs/nullfs/null_vfsops.c
===================================================================
--- sys/fs/nullfs/null_vfsops.c
+++ sys/fs/nullfs/null_vfsops.c
@@ -195,7 +195,8 @@
}
mp->mnt_kern_flag |= MNTK_LOOKUP_EXCL_DOTDOT | MNTK_NOMSYNC;
mp->mnt_kern_flag |= lowerrootvp->v_mount->mnt_kern_flag &
- (MNTK_USES_BCACHE | MNTK_NO_IOPF | MNTK_UNMAPPED_BUFS);
+ (MNTK_USES_BCACHE | MNTK_NO_IOPF | MNTK_UNMAPPED_BUFS |
+ MNTK_PGCACHE_READ);
MNT_IUNLOCK(mp);
vfs_getnewfsid(mp);
if ((xmp->nullm_flags & NULLM_CACHE) != 0) {
Index: sys/kern/vfs_vnops.c
===================================================================
--- sys/kern/vfs_vnops.c
+++ sys/kern/vfs_vnops.c
@@ -132,6 +132,10 @@
static int vn_io_fault_prefault = 0;
SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RW,
&vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting");
+static int vn_io_pgcache_read_enable = 1;
+SYSCTL_INT(_debug, OID_AUTO, vn_io_pgcache_read_enable, CTLFLAG_RW,
+ &vn_io_pgcache_read_enable, 0,
+ "Enable copying from page cache for reads, avoiding fs");
static u_long vn_io_faults_cnt;
SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
&vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
@@ -155,6 +159,21 @@
(mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
}
+/*
+ * Does not enable page cache read for tmpfs.
+ */
+static bool
+do_vn_read_from_pgcache(struct vnode *vp, struct uio *uio, struct file *fp)
+{
+ struct mount *mp;
+
+ return (vp->v_type == VREG && (mp = vp->v_mount) != NULL &&
+ (mp->mnt_kern_flag & MNTK_PGCACHE_READ) != 0 &&
+ vp->v_object != NULL && vp->v_object->type == OBJT_VNODE &&
+ uio->uio_resid <= ptoa(io_hold_cnt) && uio->uio_offset >= 0 &&
+ (fp->f_flag & O_DIRECT) == 0 && vn_io_pgcache_read_enable);
+}
+
/*
* Structure used to pass arguments to vn_io_fault1(), to do either
* file- or vnode-based I/O calls.
@@ -844,6 +863,64 @@
return (ret);
}
+static int
+vn_read_from_obj(vm_object_t obj, struct uio *uio)
+{
+ vm_page_t ma[io_hold_cnt + 2];
+ off_t off, vsz;
+ ssize_t resid;
+ int error, i, j;
+
+ MPASS(uio->uio_resid <= ptoa(io_hold_cnt + 2));
+ MPASS(obj->type == OBJT_VNODE);
+
+ resid = uio->uio_resid;
+ off = uio->uio_offset;
+ for (i = 0; resid > 0; i++) {
+ MPASS(i < io_hold_cnt + 2);
+ ma[i] = vm_page_grab_unlocked(obj, atop(off),
+ VM_ALLOC_NOCREAT | VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY |
+ (i == 0 ? 0 : VM_ALLOC_NOWAIT));
+ if (ma[i] == NULL)
+ break;
+
+ /*
+ * Skip invalid pages. Valid mask can be partial only
+ * at EOF, and we clip later.
+ */
+ if (ma[i]->valid == 0) {
+ vm_page_sunbusy(ma[i]);
+ i--;
+ }
+
+ resid -= PAGE_SIZE;
+ off += PAGE_SIZE;
+ }
+ if (i > 0) {
+ resid = PAGE_SIZE - (uio->uio_offset & PAGE_MASK) + atop(i - 1);
+ if (resid > uio->uio_resid)
+ resid = uio->uio_resid;
+
+ /*
+ * Unlocked read of vnp_size is safe because
+ * truncation cannot pass busied page. But we load
+ * vnp_size into a local variable so that possible
+ * concurrent extension does not break calculation.
+ */
+ vsz = obj->un_pager.vnp.vnp_size;
+ if (uio->uio_offset + resid > vsz)
+ resid = vsz - uio->uio_offset;
+
+ error = vn_io_fault_pgmove(ma, uio->uio_offset & PAGE_MASK,
+ resid, uio);
+ for (j = 0; j < i; j++)
+ vm_page_sunbusy(ma[j]);
+ if (error != 0)
+ return (error);
+ }
+ return (uio->uio_resid == 0 ? 0 : EJUSTRETURN);
+}
+
/*
* File table vnode read routine.
*/
@@ -860,6 +937,16 @@
uio->uio_td, td));
KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
vp = fp->f_vnode;
+ if (do_vn_read_from_pgcache(vp, uio, fp)) {
+/* XXX MAC */
+ error = vn_read_from_obj(vp->v_object, uio);
+ if (error == 0) {
+ fp->f_nextoff[UIO_READ] = uio->uio_offset;
+ return (0);
+ }
+ if (error != EJUSTRETURN)
+ return (error);
+ }
ioflag = 0;
if (fp->f_flag & FNONBLOCK)
ioflag |= IO_NDELAY;
@@ -1164,8 +1251,8 @@
uio_clone->uio_iovcnt--;
continue;
}
- if (len > io_hold_cnt * PAGE_SIZE)
- len = io_hold_cnt * PAGE_SIZE;
+ if (len > ptoa(io_hold_cnt))
+ len = ptoa(io_hold_cnt);
addr = (uintptr_t)uio_clone->uio_iov->iov_base;
end = round_page(addr + len);
if (end < addr) {
Index: sys/sys/mount.h
===================================================================
--- sys/sys/mount.h
+++ sys/sys/mount.h
@@ -421,6 +421,7 @@
#define MNTK_VMSETSIZE_BUG 0x00010000
#define MNTK_UNIONFS 0x00020000 /* A hack for F_ISUNIONSTACK */
#define MNTK_FPLOOKUP 0x00040000 /* fast path lookup is supported */
+#define MNTK_PGCACHE_READ 0x00080000 /* vn_read tries pgcache first */
#define MNTK_NOASYNC 0x00800000 /* disable async */
#define MNTK_UNMOUNT 0x01000000 /* unmount in progress */
#define MNTK_MWAIT 0x02000000 /* waiting for unmount to finish */
Index: sys/ufs/ffs/ffs_vfsops.c
===================================================================
--- sys/ufs/ffs/ffs_vfsops.c
+++ sys/ufs/ffs/ffs_vfsops.c
@@ -1296,7 +1296,8 @@
*/
MNT_ILOCK(mp);
mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED |
- MNTK_NO_IOPF | MNTK_UNMAPPED_BUFS | MNTK_USES_BCACHE;
+ MNTK_NO_IOPF | MNTK_UNMAPPED_BUFS | MNTK_USES_BCACHE |
+ MNTK_PGCACHE_READ;
MNT_IUNLOCK(mp);
#ifdef UFS_EXTATTR
#ifdef UFS_EXTATTR_AUTOSTART

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