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Retire the 'i_reclen' field from the in-memory i-node. Previously,

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during a DELETE lookup operation, lookup would cache the length of the
directory entry to be deleted in 'i_reclen'.  Later, the actual VOP to
remove the directory entry (ufs_remove, ufs_rename, etc.) would call
ufs_dirremove() which extended the length of the previous directory
entry to "remove" the deleted entry.

However, we always read the entire block containing the directory
entry when doing the removal, so we always have the directory entry to
be deleted in-memory when doing the update to the directory block.
Also, we already have to figure out where the directory entry that is
being removed is in the block so that we can pass the component name
to the dirhash code to update the dirhash.  So, instead of passing
'i_reclen' from ufs_lookup() to the ufs_dirremove() routine, just read
the 'd_reclen' field directly out of the entry being removed when
updating the length of the previous entry in the block.

This avoids a cosmetic issue of writing to 'i_reclen' while holding a
shared vnode lock.  It also slightly reduces the amount of side-band
data passed from ufs_lookup() to operations updating a directory via
the directory's i-node.

Reviewed by:	jeff
This commit is contained in:
John Baldwin 2008-09-16 19:06:44 +00:00
parent 8c83611684
commit c481551083
2 changed files with 9 additions and 7 deletions
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1
sys/ufs/ufs/inode.h
View File

@ -82,7 +82,6 @@ struct inode {
doff_t i_endoff; /* End of useful stuff in directory. */
doff_t i_diroff; /* Offset in dir, where we found last entry. */
doff_t i_offset; /* Offset of free space in directory. */
u_int32_t i_reclen; /* Size of found directory entry. */
union {
struct dirhash *dirhash; /* Hashing for large directories. */

15
sys/ufs/ufs/ufs_lookup.c
View File

@ -362,14 +362,12 @@ ufs_lookup(ap)
slotstatus = FOUND;
slotoffset = i_offset;
slotsize = ep->d_reclen;
dp->i_reclen = slotsize;
enduseful = dp->i_size;
ap->a_cnp->cn_flags |= ISWHITEOUT;
numdirpasses--;
goto notfound;
}
ino = ep->d_ino;
dp->i_reclen = ep->d_reclen;
goto found;
}
}
@ -1005,7 +1003,7 @@ ufs_dirremove(dvp, ip, flags, isrmdir)
int isrmdir;
{
struct inode *dp;
struct direct *ep;
struct direct *ep, *rep;
struct buf *bp;
int error;
@ -1026,14 +1024,19 @@ ufs_dirremove(dvp, ip, flags, isrmdir)
if ((error = UFS_BLKATOFF(dvp,
(off_t)(dp->i_offset - dp->i_count), (char **)&ep, &bp)) != 0)
return (error);
/* Set 'rep' to the entry being removed. */
if (dp->i_count == 0)
rep = ep;
else
rep = (struct direct *)((char *)ep + ep->d_reclen);
#ifdef UFS_DIRHASH
/*
* Remove the dirhash entry. This is complicated by the fact
* that `ep' is the previous entry when dp->i_count != 0.
*/
if (dp->i_dirhash != NULL)
ufsdirhash_remove(dp, (dp->i_count == 0) ? ep :
(struct direct *)((char *)ep + ep->d_reclen), dp->i_offset);
ufsdirhash_remove(dp, rep, dp->i_offset);
#endif
if (dp->i_count == 0) {
/*
@ -1044,7 +1047,7 @@ ufs_dirremove(dvp, ip, flags, isrmdir)
/*
* Collapse new free space into previous entry.
*/
ep->d_reclen += dp->i_reclen;
ep->d_reclen += rep->d_reclen;
}
#ifdef UFS_DIRHASH
if (dp->i_dirhash != NULL)