From cfa853e47df4fbee441ac0ac3fb592f076233145 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 22 Apr 2008 17:34:06 +1000 Subject: [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 Signed-off-by: Lachlan McIlroy --- fs/xfs/xfs_rename.c | 185 +++++++++++++--------------------------------------- 1 file changed, 45 insertions(+), 140 deletions(-) (limited to 'fs/xfs/xfs_rename.c') 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, -- cgit v1.2.3 From 1ac74e01df959e3e91baded7c83399372af945a2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 22 Apr 2008 17:34:12 +1000 Subject: [XFS] kill usesless IHOLD calls in xfs_rename Similar to to the previous patch for remove and rmdir only grab a reference to inodes when we join them to transaction to balance the decrement on transaction completion. Everything else it taken care of by the VFS. Note that the old case had leaks of inode count when src == target or src or target == one of the parent inodes, but these cases are fortunately already rejected by the VFS. SGI-PV: 976035 SGI-Modid: xfs-linux-melb:xfs-kern:30904a Signed-off-by: Christoph Hellwig Signed-off-by: Lachlan McIlroy --- fs/xfs/xfs_rename.c | 75 +++++++---------------------------------------------- 1 file changed, 10 insertions(+), 65 deletions(-) (limited to 'fs/xfs/xfs_rename.c') diff --git a/fs/xfs/xfs_rename.c b/fs/xfs/xfs_rename.c index 6a141427f68a..d8063e1ad298 100644 --- a/fs/xfs/xfs_rename.c +++ b/fs/xfs/xfs_rename.c @@ -137,9 +137,7 @@ xfs_rename( int cancel_flags; int committed; xfs_inode_t *inodes[4]; - int target_ip_dropped = 0; /* dropped target_ip link? */ int spaceres; - int target_link_zero = 0; int num_inodes; xfs_itrace_entry(src_dp); @@ -174,10 +172,6 @@ xfs_rename( xfs_sort_for_rename(src_dp, target_dp, src_ip, target_ip, inodes, &num_inodes); - IHOLD(src_ip); - if (target_ip) - IHOLD(target_ip); - XFS_BMAP_INIT(&free_list, &first_block); tp = xfs_trans_alloc(mp, XFS_TRANS_RENAME); cancel_flags = XFS_TRANS_RELEASE_LOG_RES; @@ -191,7 +185,7 @@ xfs_rename( } if (error) { xfs_trans_cancel(tp, 0); - goto rele_return; + goto std_return; } /* @@ -199,7 +193,7 @@ xfs_rename( */ if ((error = XFS_QM_DQVOPRENAME(mp, inodes))) { xfs_trans_cancel(tp, cancel_flags); - goto rele_return; + goto std_return; } /* @@ -220,7 +214,7 @@ xfs_rename( error = XFS_ERROR(EXDEV); xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED); xfs_trans_cancel(tp, cancel_flags); - goto rele_return; + goto std_return; } /* @@ -233,17 +227,17 @@ xfs_rename( */ IHOLD(src_dp); xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL); + if (new_parent) { IHOLD(target_dp); xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL); } - if ((src_ip != src_dp) && (src_ip != target_dp)) { - xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL); - } - if ((target_ip != NULL) && - (target_ip != src_ip) && - (target_ip != src_dp) && - (target_ip != target_dp)) { + + IHOLD(src_ip); + xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL); + + if (target_ip) { + IHOLD(target_ip); xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL); } @@ -317,7 +311,6 @@ xfs_rename( error = xfs_droplink(tp, target_ip); if (error) goto abort_return; - target_ip_dropped = 1; if (src_is_directory) { /* @@ -327,10 +320,6 @@ xfs_rename( if (error) goto abort_return; } - - /* Do this test while we still hold the locks */ - target_link_zero = (target_ip)->i_d.di_nlink==0; - } /* target_ip != NULL */ /* @@ -396,15 +385,6 @@ xfs_rename( xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE); } - /* - * If there was a target inode, take an extra reference on - * it here so that it doesn't go to xfs_inactive() from - * within the commit. - */ - if (target_ip != NULL) { - IHOLD(target_ip); - } - /* * If this is a synchronous mount, make sure that the * rename transaction goes to disk before returning to @@ -414,30 +394,11 @@ xfs_rename( xfs_trans_set_sync(tp); } - /* - * Take refs. for vop_link_removed calls below. No need to worry - * about directory refs. because the caller holds them. - * - * Do holds before the xfs_bmap_finish since it might rele them down - * to zero. - */ - - if (target_ip_dropped) - IHOLD(target_ip); - IHOLD(src_ip); - error = xfs_bmap_finish(&tp, &free_list, &committed); if (error) { xfs_bmap_cancel(&free_list); xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT)); - if (target_ip != NULL) { - IRELE(target_ip); - } - if (target_ip_dropped) { - IRELE(target_ip); - } - IRELE(src_ip); goto std_return; } @@ -446,15 +407,6 @@ xfs_rename( * the vnode references. */ error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); - if (target_ip != NULL) - IRELE(target_ip); - /* - * Let interposed file systems know about removed links. - */ - if (target_ip_dropped) - IRELE(target_ip); - - IRELE(src_ip); /* Fall through to std_return with error = 0 or errno from * xfs_trans_commit */ @@ -476,11 +428,4 @@ std_return: xfs_bmap_cancel(&free_list); xfs_trans_cancel(tp, cancel_flags); goto std_return; - - rele_return: - IRELE(src_ip); - if (target_ip != NULL) { - IRELE(target_ip); - } - goto std_return; } -- cgit v1.2.3