From b4df6ed8db0c387d38292e31f00adc4cd297ed5a Mon Sep 17 00:00:00 2001 From: Mark Fasheh Date: Wed, 22 Feb 2006 17:35:08 -0800 Subject: [PATCH] ocfs2: fix orphan recovery deadlock Orphan dir recovery can deadlock with another process in ocfs2_delete_inode() in some corner cases. Fix this by tracking recovery state more closely and allowing it to handle inode wipes which might deadlock. Signed-off-by: Mark Fasheh --- fs/ocfs2/journal.c | 124 +++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 93 insertions(+), 31 deletions(-) (limited to 'fs/ocfs2/journal.c') diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c index d329c9df90a..4be801f4559 100644 --- a/fs/ocfs2/journal.c +++ b/fs/ocfs2/journal.c @@ -1408,21 +1408,17 @@ bail: return status; } -static int ocfs2_recover_orphans(struct ocfs2_super *osb, - int slot) +static int ocfs2_queue_orphans(struct ocfs2_super *osb, + int slot, + struct inode **head) { - int status = 0; - int have_disk_lock = 0; - struct inode *inode = NULL; - struct inode *iter; + int status; struct inode *orphan_dir_inode = NULL; + struct inode *iter; unsigned long offset, blk, local; struct buffer_head *bh = NULL; struct ocfs2_dir_entry *de; struct super_block *sb = osb->sb; - struct ocfs2_inode_info *oi; - - mlog(0, "Recover inodes from orphan dir in slot %d\n", slot); orphan_dir_inode = ocfs2_get_system_file_inode(osb, ORPHAN_DIR_SYSTEM_INODE, @@ -1430,17 +1426,15 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb, if (!orphan_dir_inode) { status = -ENOENT; mlog_errno(status); - goto out; - } + return status; + } mutex_lock(&orphan_dir_inode->i_mutex); status = ocfs2_meta_lock(orphan_dir_inode, NULL, NULL, 0); if (status < 0) { - mutex_unlock(&orphan_dir_inode->i_mutex); mlog_errno(status); goto out; } - have_disk_lock = 1; offset = 0; iter = NULL; @@ -1451,11 +1445,10 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb, if (!bh) status = -EINVAL; if (status < 0) { - mutex_unlock(&orphan_dir_inode->i_mutex); if (bh) brelse(bh); mlog_errno(status); - goto out; + goto out_unlock; } local = 0; @@ -1465,11 +1458,10 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb, if (!ocfs2_check_dir_entry(orphan_dir_inode, de, bh, local)) { - mutex_unlock(&orphan_dir_inode->i_mutex); status = -EINVAL; mlog_errno(status); brelse(bh); - goto out; + goto out_unlock; } local += le16_to_cpu(de->rec_len); @@ -1504,18 +1496,95 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb, mlog(0, "queue orphan %"MLFu64"\n", OCFS2_I(iter)->ip_blkno); - OCFS2_I(iter)->ip_next_orphan = inode; - inode = iter; + /* No locking is required for the next_orphan + * queue as there is only ever a single + * process doing orphan recovery. */ + OCFS2_I(iter)->ip_next_orphan = *head; + *head = iter; } brelse(bh); } - mutex_unlock(&orphan_dir_inode->i_mutex); +out_unlock: ocfs2_meta_unlock(orphan_dir_inode, 0); - have_disk_lock = 0; - +out: + mutex_unlock(&orphan_dir_inode->i_mutex); iput(orphan_dir_inode); - orphan_dir_inode = NULL; + return status; +} + +static int ocfs2_orphan_recovery_can_continue(struct ocfs2_super *osb, + int slot) +{ + int ret; + + spin_lock(&osb->osb_lock); + ret = !osb->osb_orphan_wipes[slot]; + spin_unlock(&osb->osb_lock); + return ret; +} + +static void ocfs2_mark_recovering_orphan_dir(struct ocfs2_super *osb, + int slot) +{ + spin_lock(&osb->osb_lock); + /* Mark ourselves such that new processes in delete_inode() + * know to quit early. */ + ocfs2_node_map_set_bit(osb, &osb->osb_recovering_orphan_dirs, slot); + while (osb->osb_orphan_wipes[slot]) { + /* If any processes are already in the middle of an + * orphan wipe on this dir, then we need to wait for + * them. */ + spin_unlock(&osb->osb_lock); + wait_event_interruptible(osb->osb_wipe_event, + ocfs2_orphan_recovery_can_continue(osb, slot)); + spin_lock(&osb->osb_lock); + } + spin_unlock(&osb->osb_lock); +} + +static void ocfs2_clear_recovering_orphan_dir(struct ocfs2_super *osb, + int slot) +{ + ocfs2_node_map_clear_bit(osb, &osb->osb_recovering_orphan_dirs, slot); +} + +/* + * Orphan recovery. Each mounted node has it's own orphan dir which we + * must run during recovery. Our strategy here is to build a list of + * the inodes in the orphan dir and iget/iput them. The VFS does + * (most) of the rest of the work. + * + * Orphan recovery can happen at any time, not just mount so we have a + * couple of extra considerations. + * + * - We grab as many inodes as we can under the orphan dir lock - + * doing iget() outside the orphan dir risks getting a reference on + * an invalid inode. + * - We must be sure not to deadlock with other processes on the + * system wanting to run delete_inode(). This can happen when they go + * to lock the orphan dir and the orphan recovery process attempts to + * iget() inside the orphan dir lock. This can be avoided by + * advertising our state to ocfs2_delete_inode(). + */ +static int ocfs2_recover_orphans(struct ocfs2_super *osb, + int slot) +{ + int ret = 0; + struct inode *inode = NULL; + struct inode *iter; + struct ocfs2_inode_info *oi; + + mlog(0, "Recover inodes from orphan dir in slot %d\n", slot); + + ocfs2_mark_recovering_orphan_dir(osb, slot); + ret = ocfs2_queue_orphans(osb, slot, &inode); + ocfs2_clear_recovering_orphan_dir(osb, slot); + + /* Error here should be noted, but we want to continue with as + * many queued inodes as we've got. */ + if (ret) + mlog_errno(ret); while (inode) { oi = OCFS2_I(inode); @@ -1541,14 +1610,7 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb, inode = iter; } -out: - if (have_disk_lock) - ocfs2_meta_unlock(orphan_dir_inode, 0); - - if (orphan_dir_inode) - iput(orphan_dir_inode); - - return status; + return ret; } static int ocfs2_wait_on_mount(struct ocfs2_super *osb) -- cgit v1.2.3