diff options
| -rw-r--r-- | fs/ext4/namei.c | 109 |
1 files changed, 65 insertions, 44 deletions
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index eb61584ca5a5..3520ab8a6639 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2540,13 +2540,17 @@ static int empty_dir(struct inode *inode) return 1; } -/* ext4_orphan_add() links an unlinked or truncated inode into a list of +/* + * ext4_orphan_add() links an unlinked or truncated inode into a list of * such inodes, starting at the superblock, in case we crash before the * file is closed/deleted, or in case the inode truncate spans multiple * transactions and the last transaction is not recovered after a crash. * * At filesystem recovery time, we walk this list deleting unlinked * inodes and truncating linked inodes in ext4_orphan_cleanup(). + * + * Orphan list manipulation functions must be called under i_mutex unless + * we are just creating the inode or deleting it. */ int ext4_orphan_add(handle_t *handle, struct inode *inode) { @@ -2554,13 +2558,19 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode) struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_iloc iloc; int err = 0, rc; + bool dirty = false; if (!sbi->s_journal) return 0; - mutex_lock(&sbi->s_orphan_lock); + WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && + !mutex_is_locked(&inode->i_mutex)); + /* + * Exit early if inode already is on orphan list. This is a big speedup + * since we don't have to contend on the global s_orphan_lock. + */ if (!list_empty(&EXT4_I(inode)->i_orphan)) - goto out_unlock; + return 0; /* * Orphan handling is only valid for files with data blocks @@ -2574,44 +2584,47 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode) BUFFER_TRACE(sbi->s_sbh, "get_write_access"); err = ext4_journal_get_write_access(handle, sbi->s_sbh); if (err) - goto out_unlock; + goto out; err = ext4_reserve_inode_write(handle, inode, &iloc); if (err) - goto out_unlock; + goto out; + + mutex_lock(&sbi->s_orphan_lock); /* * Due to previous errors inode may be already a part of on-disk * orphan list. If so skip on-disk list modification. */ - if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <= - (le32_to_cpu(sbi->s_es->s_inodes_count))) - goto mem_insert; - - /* Insert this inode at the head of the on-disk orphan list... */ - NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan); - sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); - err = ext4_handle_dirty_super(handle, sb); - rc = ext4_mark_iloc_dirty(handle, inode, &iloc); - if (!err) - err = rc; - - /* Only add to the head of the in-memory list if all the - * previous operations succeeded. If the orphan_add is going to - * fail (possibly taking the journal offline), we can't risk - * leaving the inode on the orphan list: stray orphan-list - * entries can cause panics at unmount time. - * - * This is safe: on error we're going to ignore the orphan list - * anyway on the next recovery. */ -mem_insert: - if (!err) - list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan); + if (!NEXT_ORPHAN(inode) || NEXT_ORPHAN(inode) > + (le32_to_cpu(sbi->s_es->s_inodes_count))) { + /* Insert this inode at the head of the on-disk orphan list */ + NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan); + sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); + dirty = true; + } + list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan); + mutex_unlock(&sbi->s_orphan_lock); + if (dirty) { + err = ext4_handle_dirty_super(handle, sb); + rc = ext4_mark_iloc_dirty(handle, inode, &iloc); + if (!err) + err = rc; + if (err) { + /* + * We have to remove inode from in-memory list if + * addition to on disk orphan list failed. Stray orphan + * list entries can cause panics at unmount time. + */ + mutex_lock(&sbi->s_orphan_lock); + list_del(&EXT4_I(inode)->i_orphan); + mutex_unlock(&sbi->s_orphan_lock); + } + } jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); jbd_debug(4, "orphan inode %lu will point to %d\n", inode->i_ino, NEXT_ORPHAN(inode)); -out_unlock: - mutex_unlock(&sbi->s_orphan_lock); +out: ext4_std_error(sb, err); return err; } @@ -2632,35 +2645,43 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode) if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS)) return 0; - mutex_lock(&sbi->s_orphan_lock); + WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && + !mutex_is_locked(&inode->i_mutex)); + /* Do this quick check before taking global s_orphan_lock. */ if (list_empty(&ei->i_orphan)) - goto out; + return 0; - ino_next = NEXT_ORPHAN(inode); - prev = ei->i_orphan.prev; + if (handle) { + /* Grab inode buffer early before taking global s_orphan_lock */ + err = ext4_reserve_inode_write(handle, inode, &iloc); + } + mutex_lock(&sbi->s_orphan_lock); jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); + prev = ei->i_orphan.prev; list_del_init(&ei->i_orphan); /* If we're on an error path, we may not have a valid * transaction handle with which to update the orphan list on * disk, but we still need to remove the inode from the linked * list in memory. */ - if (!handle) - goto out; - - err = ext4_reserve_inode_write(handle, inode, &iloc); - if (err) + if (!handle || err) { + mutex_unlock(&sbi->s_orphan_lock); goto out_err; + } + ino_next = NEXT_ORPHAN(inode); if (prev == &sbi->s_orphan) { jbd_debug(4, "superblock will point to %u\n", ino_next); BUFFER_TRACE(sbi->s_sbh, "get_write_access"); err = ext4_journal_get_write_access(handle, sbi->s_sbh); - if (err) + if (err) { + mutex_unlock(&sbi->s_orphan_lock); goto out_brelse; + } sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); + mutex_unlock(&sbi->s_orphan_lock); err = ext4_handle_dirty_super(handle, inode->i_sb); } else { struct ext4_iloc iloc2; @@ -2670,20 +2691,20 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode) jbd_debug(4, "orphan inode %lu will point to %u\n", i_prev->i_ino, ino_next); err = ext4_reserve_inode_write(handle, i_prev, &iloc2); - if (err) + if (err) { + mutex_unlock(&sbi->s_orphan_lock); goto out_brelse; + } NEXT_ORPHAN(i_prev) = ino_next; err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); + mutex_unlock(&sbi->s_orphan_lock); } if (err) goto out_brelse; NEXT_ORPHAN(inode) = 0; err = ext4_mark_iloc_dirty(handle, inode, &iloc); - out_err: ext4_std_error(inode->i_sb, err); -out: - mutex_unlock(&sbi->s_orphan_lock); return err; out_brelse: |