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authorChristoph Hellwig <hch@infradead.org>2008-04-22 17:34:06 +1000
committerLachlan McIlroy <lachlan@redback.melbourne.sgi.com>2008-04-29 15:54:12 +1000
commitcfa853e47df4fbee441ac0ac3fb592f076233145 (patch)
tree7e4baafba5ee0f05561580c301c5d360236063f3 /fs/xfs/xfs_rename.c
parent579aa9caf552c639fc78168db4cfe7ffcf00c3b3 (diff)
[XFS] remove manual lookup from xfs_rename and simplify locking
->rename already gets the target inode passed if it exits. Pass it down to xfs_rename so that we can avoid looking it up again. Also simplify locking as the first lock section in xfs_rename can go away now: the isdir is an invariant over the lifetime of the inode, and new_parent and the nlink check are namespace topology protected by i_mutex in the VFS. The projid check needs to move into the second lock section anyway to not be racy. Also kill the now unused xfs_dir_lookup_int and remove the now-unused first_locked argumet to xfs_lock_inodes. SGI-PV: 976035 SGI-Modid: xfs-linux-melb:xfs-kern:30903a Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_rename.c')
-rw-r--r--fs/xfs/xfs_rename.c185
1 files changed, 45 insertions, 140 deletions
diff --git a/fs/xfs/xfs_rename.c b/fs/xfs/xfs_rename.c
index ee371890d85d..6a141427f68a 100644
--- a/fs/xfs/xfs_rename.c
+++ b/fs/xfs/xfs_rename.c
@@ -55,85 +55,32 @@ xfs_rename_unlock4(
xfs_iunlock(i_tab[0], lock_mode);
for (i = 1; i < 4; i++) {
- if (i_tab[i] == NULL) {
+ if (i_tab[i] == NULL)
break;
- }
+
/*
* Watch out for duplicate entries in the table.
*/
- if (i_tab[i] != i_tab[i-1]) {
+ if (i_tab[i] != i_tab[i-1])
xfs_iunlock(i_tab[i], lock_mode);
- }
}
}
-#ifdef DEBUG
-int xfs_rename_skip, xfs_rename_nskip;
-#endif
-
/*
- * The following routine will acquire the locks required for a rename
- * operation. The code understands the semantics of renames and will
- * validate that name1 exists under dp1 & that name2 may or may not
- * exist under dp2.
- *
- * We are renaming dp1/name1 to dp2/name2.
- *
- * Return ENOENT if dp1 does not exist, other lookup errors, or 0 for success.
+ * Enter all inodes for a rename transaction into a sorted array.
*/
-STATIC int
-xfs_lock_for_rename(
+STATIC void
+xfs_sort_for_rename(
xfs_inode_t *dp1, /* in: old (source) directory inode */
xfs_inode_t *dp2, /* in: new (target) directory inode */
xfs_inode_t *ip1, /* in: inode of old entry */
- struct xfs_name *name2, /* in: new entry name */
- xfs_inode_t **ipp2, /* out: inode of new entry, if it
+ xfs_inode_t *ip2, /* in: inode of new entry, if it
already exists, NULL otherwise. */
xfs_inode_t **i_tab,/* out: array of inode returned, sorted */
int *num_inodes) /* out: number of inodes in array */
{
- xfs_inode_t *ip2 = NULL;
xfs_inode_t *temp;
- xfs_ino_t inum1, inum2;
- int error;
int i, j;
- uint lock_mode;
- int diff_dirs = (dp1 != dp2);
-
- /*
- * First, find out the current inums of the entries so that we
- * can determine the initial locking order. We'll have to
- * sanity check stuff after all the locks have been acquired
- * to see if we still have the right inodes, directories, etc.
- */
- lock_mode = xfs_ilock_map_shared(dp1);
- IHOLD(ip1);
- xfs_itrace_ref(ip1);
-
- inum1 = ip1->i_ino;
-
- /*
- * Unlock dp1 and lock dp2 if they are different.
- */
- if (diff_dirs) {
- xfs_iunlock_map_shared(dp1, lock_mode);
- lock_mode = xfs_ilock_map_shared(dp2);
- }
-
- error = xfs_dir_lookup_int(dp2, lock_mode, name2, &inum2, &ip2);
- if (error == ENOENT) { /* target does not need to exist. */
- inum2 = 0;
- } else if (error) {
- /*
- * If dp2 and dp1 are the same, the next line unlocks dp1.
- * Got it?
- */
- xfs_iunlock_map_shared(dp2, lock_mode);
- IRELE (ip1);
- return error;
- } else {
- xfs_itrace_ref(ip2);
- }
/*
* i_tab contains a list of pointers to inodes. We initialize
@@ -145,21 +92,20 @@ xfs_lock_for_rename(
i_tab[0] = dp1;
i_tab[1] = dp2;
i_tab[2] = ip1;
- if (inum2 == 0) {
- *num_inodes = 3;
- i_tab[3] = NULL;
- } else {
+ if (ip2) {
*num_inodes = 4;
i_tab[3] = ip2;
+ } else {
+ *num_inodes = 3;
+ i_tab[3] = NULL;
}
- *ipp2 = i_tab[3];
/*
* Sort the elements via bubble sort. (Remember, there are at
* most 4 elements to sort, so this is adequate.)
*/
- for (i=0; i < *num_inodes; i++) {
- for (j=1; j < *num_inodes; j++) {
+ for (i = 0; i < *num_inodes; i++) {
+ for (j = 1; j < *num_inodes; j++) {
if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
temp = i_tab[j];
i_tab[j] = i_tab[j-1];
@@ -167,30 +113,6 @@ xfs_lock_for_rename(
}
}
}
-
- /*
- * We have dp2 locked. If it isn't first, unlock it.
- * If it is first, tell xfs_lock_inodes so it can skip it
- * when locking. if dp1 == dp2, xfs_lock_inodes will skip both
- * since they are equal. xfs_lock_inodes needs all these inodes
- * so that it can unlock and retry if there might be a dead-lock
- * potential with the log.
- */
-
- if (i_tab[0] == dp2 && lock_mode == XFS_ILOCK_SHARED) {
-#ifdef DEBUG
- xfs_rename_skip++;
-#endif
- xfs_lock_inodes(i_tab, *num_inodes, 1, XFS_ILOCK_SHARED);
- } else {
-#ifdef DEBUG
- xfs_rename_nskip++;
-#endif
- xfs_iunlock_map_shared(dp2, lock_mode);
- xfs_lock_inodes(i_tab, *num_inodes, 0, XFS_ILOCK_SHARED);
- }
-
- return 0;
}
/*
@@ -202,10 +124,10 @@ xfs_rename(
struct xfs_name *src_name,
xfs_inode_t *src_ip,
xfs_inode_t *target_dp,
- struct xfs_name *target_name)
+ struct xfs_name *target_name,
+ xfs_inode_t *target_ip)
{
- xfs_trans_t *tp;
- xfs_inode_t *target_ip;
+ xfs_trans_t *tp = NULL;
xfs_mount_t *mp = src_dp->i_mount;
int new_parent; /* moving to a new dir */
int src_is_directory; /* src_name is a directory */
@@ -230,64 +152,31 @@ xfs_rename(
target_dp, DM_RIGHT_NULL,
src_name->name, target_name->name,
0, 0, 0);
- if (error) {
+ if (error)
return error;
- }
}
/* Return through std_return after this point. */
- /*
- * Lock all the participating inodes. Depending upon whether
- * the target_name exists in the target directory, and
- * whether the target directory is the same as the source
- * directory, we can lock from 2 to 4 inodes.
- * xfs_lock_for_rename() will return ENOENT if src_name
- * does not exist in the source directory.
- */
- tp = NULL;
- error = xfs_lock_for_rename(src_dp, target_dp, src_ip, target_name,
- &target_ip, inodes, &num_inodes);
- if (error) {
- /*
- * We have nothing locked, no inode references, and
- * no transaction, so just get out.
- */
- goto std_return;
- }
-
- ASSERT(src_ip != NULL);
+ new_parent = (src_dp != target_dp);
+ src_is_directory = ((src_ip->i_d.di_mode & S_IFMT) == S_IFDIR);
- if ((src_ip->i_d.di_mode & S_IFMT) == S_IFDIR) {
+ if (src_is_directory) {
/*
* Check for link count overflow on target_dp
*/
- if (target_ip == NULL && (src_dp != target_dp) &&
+ if (target_ip == NULL && new_parent &&
target_dp->i_d.di_nlink >= XFS_MAXLINK) {
error = XFS_ERROR(EMLINK);
- xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);
- goto rele_return;
+ goto std_return;
}
}
- /*
- * If we are using project inheritance, we only allow renames
- * into our tree when the project IDs are the same; else the
- * tree quota mechanism would be circumvented.
- */
- if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
- (target_dp->i_d.di_projid != src_ip->i_d.di_projid))) {
- error = XFS_ERROR(EXDEV);
- xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);
- goto rele_return;
- }
-
- new_parent = (src_dp != target_dp);
- src_is_directory = ((src_ip->i_d.di_mode & S_IFMT) == S_IFDIR);
+ xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip,
+ inodes, &num_inodes);
- /*
- * Drop the locks on our inodes so that we can start the transaction.
- */
- xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);
+ IHOLD(src_ip);
+ if (target_ip)
+ IHOLD(target_ip);
XFS_BMAP_INIT(&free_list, &first_block);
tp = xfs_trans_alloc(mp, XFS_TRANS_RENAME);
@@ -314,9 +203,25 @@ xfs_rename(
}
/*
- * Reacquire the inode locks we dropped above.
+ * Lock all the participating inodes. Depending upon whether
+ * the target_name exists in the target directory, and
+ * whether the target directory is the same as the source
+ * directory, we can lock from 2 to 4 inodes.
*/
- xfs_lock_inodes(inodes, num_inodes, 0, XFS_ILOCK_EXCL);
+ xfs_lock_inodes(inodes, num_inodes, XFS_ILOCK_EXCL);
+
+ /*
+ * If we are using project inheritance, we only allow renames
+ * into our tree when the project IDs are the same; else the
+ * tree quota mechanism would be circumvented.
+ */
+ if (unlikely((target_dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&
+ (target_dp->i_d.di_projid != src_ip->i_d.di_projid))) {
+ error = XFS_ERROR(EXDEV);
+ xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);
+ xfs_trans_cancel(tp, cancel_flags);
+ goto rele_return;
+ }
/*
* Join all the inodes to the transaction. From this point on,