diff options
author | Christoph Hellwig <hch@infradead.org> | 2008-04-22 07:34:06 (GMT) |
---|---|---|
committer | Lachlan McIlroy <lachlan@redback.melbourne.sgi.com> | 2008-04-29 05:54:12 (GMT) |
commit | cfa853e47df4fbee441ac0ac3fb592f076233145 (patch) | |
tree | 7e4baafba5ee0f05561580c301c5d360236063f3 /fs/xfs/xfs_rename.c | |
parent | 579aa9caf552c639fc78168db4cfe7ffcf00c3b3 (diff) | |
download | linux-cfa853e47df4fbee441ac0ac3fb592f076233145.tar.xz |
[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.c | 185 |
1 files changed, 45 insertions, 140 deletions
diff --git a/fs/xfs/xfs_rename.c b/fs/xfs/xfs_rename.c index ee37189..6a14142 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, |