mirror of
https://git.FreeBSD.org/src.git
synced 2025-01-10 14:02:43 +00:00
- cache dp->i_offset in the local 'i_offset' variable for use in loop
indexes so directory lookup becomes shared lock safe. In the modifying cases an exclusive lock is held here so the commit routine may rely on the state of i_offset. - Similarly handle i_diroff by fetching at the start and setting only once the operation is complete. Without the exclusive lock these are only considered hints. - Assert that an exclusive lock is held when we're preparing for a commit routine. - Honor the lock type request from lookup instead of always using exclusive locking. Tested by: pho, kris
This commit is contained in:
Jeff Roberson
parent
42b1030bbd
commit
eb1314a249
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=178109
@ -137,6 +137,8 @@ ufs_lookup(ap)
|
||||
int entryoffsetinblock; /* offset of ep in bp's buffer */
|
||||
enum {NONE, COMPACT, FOUND} slotstatus;
|
||||
doff_t slotoffset; /* offset of area with free space */
|
||||
doff_t i_diroff; /* cached i_diroff value. */
|
||||
doff_t i_offset; /* cached i_offset value. */
|
||||
int slotsize; /* size of area at slotoffset */
|
||||
int slotfreespace; /* amount of space free in slot */
|
||||
int slotneeded; /* size of the entry we're seeking */
|
||||
@ -154,6 +156,7 @@ ufs_lookup(ap)
|
||||
int flags = cnp->cn_flags;
|
||||
int nameiop = cnp->cn_nameiop;
|
||||
ino_t saved_ino;
|
||||
int ltype;
|
||||
|
||||
bp = NULL;
|
||||
slotoffset = -1;
|
||||
@ -173,6 +176,7 @@ ufs_lookup(ap)
|
||||
* we watch for a place to put the new file in
|
||||
* case it doesn't already exist.
|
||||
*/
|
||||
i_diroff = dp->i_diroff;
|
||||
slotstatus = FOUND;
|
||||
slotfreespace = slotsize = slotneeded = 0;
|
||||
if ((nameiop == CREATE || nameiop == RENAME) &&
|
||||
@ -206,13 +210,13 @@ ufs_lookup(ap)
|
||||
numdirpasses = 1;
|
||||
entryoffsetinblock = 0; /* silence compiler warning */
|
||||
switch (ufsdirhash_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen,
|
||||
&dp->i_offset, &bp, nameiop == DELETE ? &prevoff : NULL)) {
|
||||
&i_offset, &bp, nameiop == DELETE ? &prevoff : NULL)) {
|
||||
case 0:
|
||||
ep = (struct direct *)((char *)bp->b_data +
|
||||
(dp->i_offset & bmask));
|
||||
(i_offset & bmask));
|
||||
goto foundentry;
|
||||
case ENOENT:
|
||||
dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ);
|
||||
i_offset = roundup2(dp->i_size, DIRBLKSIZ);
|
||||
goto notfound;
|
||||
default:
|
||||
/* Something failed; just do a linear search. */
|
||||
@ -231,33 +235,32 @@ ufs_lookup(ap)
|
||||
* profiling time and hence has been removed in the interest
|
||||
* of simplicity.
|
||||
*/
|
||||
if (nameiop != LOOKUP || dp->i_diroff == 0 ||
|
||||
dp->i_diroff >= dp->i_size) {
|
||||
if (nameiop != LOOKUP || i_diroff == 0 || i_diroff >= dp->i_size) {
|
||||
entryoffsetinblock = 0;
|
||||
dp->i_offset = 0;
|
||||
i_offset = 0;
|
||||
numdirpasses = 1;
|
||||
} else {
|
||||
dp->i_offset = dp->i_diroff;
|
||||
if ((entryoffsetinblock = dp->i_offset & bmask) &&
|
||||
(error = UFS_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp)))
|
||||
i_offset = i_diroff;
|
||||
if ((entryoffsetinblock = i_offset & bmask) &&
|
||||
(error = UFS_BLKATOFF(vdp, (off_t)i_offset, NULL, &bp)))
|
||||
return (error);
|
||||
numdirpasses = 2;
|
||||
nchstats.ncs_2passes++;
|
||||
}
|
||||
prevoff = dp->i_offset;
|
||||
prevoff = i_offset;
|
||||
endsearch = roundup2(dp->i_size, DIRBLKSIZ);
|
||||
enduseful = 0;
|
||||
|
||||
searchloop:
|
||||
while (dp->i_offset < endsearch) {
|
||||
while (i_offset < endsearch) {
|
||||
/*
|
||||
* If necessary, get the next directory block.
|
||||
*/
|
||||
if ((dp->i_offset & bmask) == 0) {
|
||||
if ((i_offset & bmask) == 0) {
|
||||
if (bp != NULL)
|
||||
brelse(bp);
|
||||
error =
|
||||
UFS_BLKATOFF(vdp, (off_t)dp->i_offset, NULL, &bp);
|
||||
UFS_BLKATOFF(vdp, (off_t)i_offset, NULL, &bp);
|
||||
if (error)
|
||||
return (error);
|
||||
entryoffsetinblock = 0;
|
||||
@ -284,9 +287,9 @@ ufs_lookup(ap)
|
||||
(dirchk && ufs_dirbadentry(vdp, ep, entryoffsetinblock))) {
|
||||
int i;
|
||||
|
||||
ufs_dirbad(dp, dp->i_offset, "mangled entry");
|
||||
ufs_dirbad(dp, i_offset, "mangled entry");
|
||||
i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
|
||||
dp->i_offset += i;
|
||||
i_offset += i;
|
||||
entryoffsetinblock += i;
|
||||
continue;
|
||||
}
|
||||
@ -305,15 +308,15 @@ ufs_lookup(ap)
|
||||
if (size > 0) {
|
||||
if (size >= slotneeded) {
|
||||
slotstatus = FOUND;
|
||||
slotoffset = dp->i_offset;
|
||||
slotoffset = i_offset;
|
||||
slotsize = ep->d_reclen;
|
||||
} else if (slotstatus == NONE) {
|
||||
slotfreespace += size;
|
||||
if (slotoffset == -1)
|
||||
slotoffset = dp->i_offset;
|
||||
slotoffset = i_offset;
|
||||
if (slotfreespace >= slotneeded) {
|
||||
slotstatus = COMPACT;
|
||||
slotsize = dp->i_offset +
|
||||
slotsize = i_offset +
|
||||
ep->d_reclen - slotoffset;
|
||||
}
|
||||
}
|
||||
@ -347,7 +350,7 @@ ufs_lookup(ap)
|
||||
if (vdp->v_mount->mnt_maxsymlinklen > 0 &&
|
||||
ep->d_type == DT_WHT) {
|
||||
slotstatus = FOUND;
|
||||
slotoffset = dp->i_offset;
|
||||
slotoffset = i_offset;
|
||||
slotsize = ep->d_reclen;
|
||||
dp->i_reclen = slotsize;
|
||||
enduseful = dp->i_size;
|
||||
@ -360,11 +363,11 @@ ufs_lookup(ap)
|
||||
goto found;
|
||||
}
|
||||
}
|
||||
prevoff = dp->i_offset;
|
||||
dp->i_offset += ep->d_reclen;
|
||||
prevoff = i_offset;
|
||||
i_offset += ep->d_reclen;
|
||||
entryoffsetinblock += ep->d_reclen;
|
||||
if (ep->d_ino)
|
||||
enduseful = dp->i_offset;
|
||||
enduseful = i_offset;
|
||||
}
|
||||
notfound:
|
||||
/*
|
||||
@ -373,10 +376,11 @@ ufs_lookup(ap)
|
||||
*/
|
||||
if (numdirpasses == 2) {
|
||||
numdirpasses--;
|
||||
dp->i_offset = 0;
|
||||
endsearch = dp->i_diroff;
|
||||
i_offset = 0;
|
||||
endsearch = i_diroff;
|
||||
goto searchloop;
|
||||
}
|
||||
dp->i_offset = i_offset;
|
||||
if (bp != NULL)
|
||||
brelse(bp);
|
||||
/*
|
||||
@ -389,6 +393,7 @@ ufs_lookup(ap)
|
||||
(ap->a_cnp->cn_flags & DOWHITEOUT) &&
|
||||
(ap->a_cnp->cn_flags & ISWHITEOUT))) &&
|
||||
(flags & ISLASTCN) && dp->i_effnlink != 0) {
|
||||
ASSERT_VOP_ELOCKED(vdp, __FUNCTION__);
|
||||
/*
|
||||
* Access for write is interpreted as allowing
|
||||
* creation of files in the directory.
|
||||
@ -452,9 +457,9 @@ ufs_lookup(ap)
|
||||
* Check that directory length properly reflects presence
|
||||
* of this entry.
|
||||
*/
|
||||
if (dp->i_offset + DIRSIZ(OFSFMT(vdp), ep) > dp->i_size) {
|
||||
ufs_dirbad(dp, dp->i_offset, "i_size too small");
|
||||
dp->i_size = dp->i_offset + DIRSIZ(OFSFMT(vdp), ep);
|
||||
if (i_offset + DIRSIZ(OFSFMT(vdp), ep) > dp->i_size) {
|
||||
ufs_dirbad(dp, i_offset, "i_size too small");
|
||||
dp->i_size = i_offset + DIRSIZ(OFSFMT(vdp), ep);
|
||||
DIP_SET(dp, i_size, dp->i_size);
|
||||
dp->i_flag |= IN_CHANGE | IN_UPDATE;
|
||||
}
|
||||
@ -466,13 +471,15 @@ ufs_lookup(ap)
|
||||
* in the cache as to where the entry was found.
|
||||
*/
|
||||
if ((flags & ISLASTCN) && nameiop == LOOKUP)
|
||||
dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1);
|
||||
dp->i_diroff = i_offset &~ (DIRBLKSIZ - 1);
|
||||
|
||||
dp->i_offset = i_offset;
|
||||
/*
|
||||
* If deleting, and at end of pathname, return
|
||||
* parameters which can be used to remove file.
|
||||
*/
|
||||
if (nameiop == DELETE && (flags & ISLASTCN)) {
|
||||
ASSERT_VOP_ELOCKED(vdp, __FUNCTION__);
|
||||
/*
|
||||
* Write access to directory required to delete files.
|
||||
*/
|
||||
@ -557,16 +564,28 @@ ufs_lookup(ap)
|
||||
*/
|
||||
pdp = vdp;
|
||||
if (flags & ISDOTDOT) {
|
||||
ltype = VOP_ISLOCKED(pdp);
|
||||
saved_ino = dp->i_ino;
|
||||
VOP_UNLOCK(pdp, 0); /* race to get the inode */
|
||||
error = VFS_VGET(pdp->v_mount, saved_ino,
|
||||
cnp->cn_lkflags, &tdp);
|
||||
vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY);
|
||||
vn_lock(pdp, ltype | LK_RETRY);
|
||||
if (error)
|
||||
return (error);
|
||||
*vpp = tdp;
|
||||
} else if (dp->i_number == dp->i_ino) {
|
||||
VREF(vdp); /* we want ourself, ie "." */
|
||||
/*
|
||||
* When we lookup "." we still can be asked to lock it
|
||||
* differently.
|
||||
*/
|
||||
ltype = cnp->cn_lkflags & LK_TYPE_MASK;
|
||||
if (ltype != VOP_ISLOCKED(vdp)) {
|
||||
if (ltype == LK_EXCLUSIVE)
|
||||
vn_lock(vdp, LK_UPGRADE | LK_RETRY);
|
||||
else /* if (ltype == LK_SHARED) */
|
||||
vn_lock(vdp, LK_DOWNGRADE | LK_RETRY);
|
||||
}
|
||||
*vpp = vdp;
|
||||
} else {
|
||||
error = VFS_VGET(pdp->v_mount, dp->i_ino,
|
||||
|
||||
Loading…
Reference in New Issue
Block a user