svn commit: r345244 - head/sys/ufs/ufs
Mark Johnston
markj at FreeBSD.org
Sun Mar 17 17:34:08 UTC 2019
Author: markj
Date: Sun Mar 17 17:34:06 2019
New Revision: 345244
URL: https://svnweb.freebsd.org/changeset/base/345244
Log:
Optimize lseek(SEEK_DATA) on UFS.
The old implementation, at the VFS layer, would map the entire range of
logical blocks between the starting offset and the first data block
following that offset. With large sparse files this is very
inefficient. The VFS currently doesn't provide an interface to improve
upon the current implementation in a generic way.
Add ufs_bmap_seekdata(), which uses the obvious algorithm of scanning
indirect blocks to look for data blocks. Use it instead of
vn_bmap_seekhole() to implement SEEK_DATA.
Reviewed by: kib, mckusick
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19598
Modified:
head/sys/ufs/ufs/ufs_bmap.c
head/sys/ufs/ufs/ufs_extern.h
head/sys/ufs/ufs/ufs_vnops.c
Modified: head/sys/ufs/ufs/ufs_bmap.c
==============================================================================
--- head/sys/ufs/ufs/ufs_bmap.c Sun Mar 17 13:02:24 2019 (r345243)
+++ head/sys/ufs/ufs/ufs_bmap.c Sun Mar 17 17:34:06 2019 (r345244)
@@ -90,6 +90,51 @@ ufs_bmap(ap)
return (error);
}
+static int
+ufs_readindir(vp, lbn, daddr, bpp)
+ struct vnode *vp;
+ ufs_lbn_t lbn;
+ ufs2_daddr_t daddr;
+ struct buf **bpp;
+{
+ struct buf *bp;
+ struct mount *mp;
+ struct ufsmount *ump;
+ int error;
+
+ mp = vp->v_mount;
+ ump = VFSTOUFS(mp);
+
+ bp = getblk(vp, lbn, mp->mnt_stat.f_iosize, 0, 0, 0);
+ if ((bp->b_flags & B_CACHE) == 0) {
+ KASSERT(daddr != 0,
+ ("ufs_readindir: indirect block not in cache"));
+
+ bp->b_blkno = blkptrtodb(ump, daddr);
+ bp->b_iocmd = BIO_READ;
+ bp->b_flags &= ~B_INVAL;
+ bp->b_ioflags &= ~BIO_ERROR;
+ vfs_busy_pages(bp, 0);
+ bp->b_iooffset = dbtob(bp->b_blkno);
+ bstrategy(bp);
+#ifdef RACCT
+ if (racct_enable) {
+ PROC_LOCK(curproc);
+ racct_add_buf(curproc, bp, 0);
+ PROC_UNLOCK(curproc);
+ }
+#endif
+ curthread->td_ru.ru_inblock++;
+ error = bufwait(bp);
+ if (error != 0) {
+ brelse(bp);
+ return (error);
+ }
+ }
+ *bpp = bp;
+ return (0);
+}
+
/*
* Indirect blocks are now on the vnode for the file. They are given negative
* logical block numbers. Indirect blocks are addressed by the negative
@@ -212,35 +257,10 @@ ufs_bmaparray(vp, bn, bnp, nbp, runp, runb)
*/
if (bp)
bqrelse(bp);
+ error = ufs_readindir(vp, metalbn, daddr, &bp);
+ if (error != 0)
+ return (error);
- bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0, 0);
- if ((bp->b_flags & B_CACHE) == 0) {
-#ifdef INVARIANTS
- if (!daddr)
- panic("ufs_bmaparray: indirect block not in cache");
-#endif
- bp->b_blkno = blkptrtodb(ump, daddr);
- bp->b_iocmd = BIO_READ;
- bp->b_flags &= ~B_INVAL;
- bp->b_ioflags &= ~BIO_ERROR;
- vfs_busy_pages(bp, 0);
- bp->b_iooffset = dbtob(bp->b_blkno);
- bstrategy(bp);
-#ifdef RACCT
- if (racct_enable) {
- PROC_LOCK(curproc);
- racct_add_buf(curproc, bp, 0);
- PROC_UNLOCK(curproc);
- }
-#endif /* RACCT */
- curthread->td_ru.ru_inblock++;
- error = bufwait(bp);
- if (error) {
- brelse(bp);
- return (error);
- }
- }
-
if (I_IS_UFS1(ip)) {
daddr = ((ufs1_daddr_t *)bp->b_data)[ap->in_off];
if (num == 1 && daddr && runp) {
@@ -301,6 +321,93 @@ ufs_bmaparray(vp, bn, bnp, nbp, runp, runb)
*bnp = -1;
}
return (0);
+}
+
+int
+ufs_bmap_seekdata(vp, offp)
+ struct vnode *vp;
+ off_t *offp;
+{
+ struct buf *bp;
+ struct indir a[UFS_NIADDR + 1], *ap;
+ struct inode *ip;
+ struct mount *mp;
+ struct ufsmount *ump;
+ ufs2_daddr_t blockcnt, bn, daddr;
+ uint64_t bsize;
+ off_t numblks;
+ int error, num, num1;
+
+ bp = NULL;
+ ip = VTOI(vp);
+ mp = vp->v_mount;
+ ump = VFSTOUFS(mp);
+
+ if (vp->v_type != VREG || (ip->i_flags & SF_SNAPSHOT) != 0)
+ return (EINVAL);
+ if (*offp < 0)
+ return (ENXIO);
+
+ bsize = mp->mnt_stat.f_iosize;
+ for (bn = *offp / bsize, numblks = howmany(ip->i_size, bsize);
+ bn < numblks;) {
+ if (bn < UFS_NDADDR) {
+ daddr = DIP(ip, i_db[bn]);
+ if (daddr != 0)
+ break;
+ bn++;
+ continue;
+ }
+
+ ap = a;
+ error = ufs_getlbns(vp, bn, ap, &num);
+ if (error != 0)
+ break;
+ MPASS(num >= 2);
+ daddr = DIP(ip, i_ib[ap->in_off]);
+ ap++, num--;
+ if (daddr == 0) {
+ for (blockcnt = 1; num > 0; num--)
+ blockcnt *= MNINDIR(ump);
+ bn += blockcnt;
+ continue;
+ }
+
+ for (; num > 0 && daddr != 0; ap++, num--) {
+ if (bp != NULL)
+ bqrelse(bp);
+ error = ufs_readindir(vp, ap->in_lbn, daddr, &bp);
+ if (error != 0)
+ return (error);
+
+ /*
+ * Precompute the number of blocks addressed by an entry
+ * of the current indirect block.
+ */
+ for (blockcnt = 1, num1 = num; num1 > 1; num1--)
+ blockcnt *= MNINDIR(ump);
+
+ for (; ap->in_off < MNINDIR(ump); ap->in_off++,
+ bn += blockcnt) {
+ daddr = I_IS_UFS1(ip) ?
+ ((ufs1_daddr_t *)bp->b_data)[ap->in_off] :
+ ((ufs2_daddr_t *)bp->b_data)[ap->in_off];
+ if (daddr != 0)
+ break;
+ }
+ }
+ if (daddr != 0) {
+ MPASS(num == 0);
+ break;
+ }
+ }
+ if (bp != NULL)
+ bqrelse(bp);
+ if (bn >= numblks)
+ error = ENXIO;
+ if (error == 0)
+ *offp = bn * bsize;
+ return (error);
}
/*
Modified: head/sys/ufs/ufs/ufs_extern.h
==============================================================================
--- head/sys/ufs/ufs/ufs_extern.h Sun Mar 17 13:02:24 2019 (r345243)
+++ head/sys/ufs/ufs/ufs_extern.h Sun Mar 17 17:34:06 2019 (r345244)
@@ -58,6 +58,7 @@ extern struct vop_vector ufs_vnodeops;
int ufs_bmap(struct vop_bmap_args *);
int ufs_bmaparray(struct vnode *, ufs2_daddr_t, ufs2_daddr_t *,
struct buf *, int *, int *);
+int ufs_bmap_seekdata(struct vnode *, off_t *);
int ufs_fhtovp(struct mount *, struct ufid *, int, struct vnode **);
int ufs_checkpath(ino_t, ino_t, struct inode *, struct ucred *, ino_t *);
void ufs_dirbad(struct inode *, doff_t, char *);
Modified: head/sys/ufs/ufs/ufs_vnops.c
==============================================================================
--- head/sys/ufs/ufs/ufs_vnops.c Sun Mar 17 13:02:24 2019 (r345243)
+++ head/sys/ufs/ufs/ufs_vnops.c Sun Mar 17 17:34:06 2019 (r345244)
@@ -2701,12 +2701,15 @@ bad:
static int
ufs_ioctl(struct vop_ioctl_args *ap)
{
+ struct vnode *vp;
+ vp = ap->a_vp;
switch (ap->a_command) {
case FIOSEEKDATA:
+ return (ufs_bmap_seekdata(vp, (off_t *)ap->a_data));
case FIOSEEKHOLE:
- return (vn_bmap_seekhole(ap->a_vp, ap->a_command,
- (off_t *)ap->a_data, ap->a_cred));
+ return (vn_bmap_seekhole(vp, ap->a_command, (off_t *)ap->a_data,
+ ap->a_cred));
default:
return (ENOTTY);
}
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