From: T Makphaibulchoke Subject: [PATCH 2/2] fs/ext4/namei.c: reducing contention on s_orphan_lock mmutex Date: Wed, 2 Oct 2013 09:36:59 -0600 Message-ID: <1380728219-60784-2-git-send-email-tmac@hp.com> References: <1380728219-60784-1-git-send-email-tmac@hp.com> Cc: aswin@hp.com, aswin_proj@lists.hp.com, T Makphaibulchoke To: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <1380728219-60784-1-git-send-email-tmac@hp.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Instead of using a single per super block mutex, s_orphan_lock, to serialize all orphan list updates, a separate mutex and spinlock are used to protect the on disk and in memory orphan lists respecvitely. At the same time, a per inode mutex is used to serialize orphan list updates of a single inode. Signed-off-by: T. Makphaibulchoke --- fs/ext4/namei.c | 139 ++++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 100 insertions(+), 39 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 35f55a0..d7d3d0f 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2554,12 +2554,24 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode) struct super_block *sb = inode->i_sb; struct ext4_iloc iloc; int err = 0, rc; + struct ext4_inode_info *ext4_inode = EXT4_I(inode); + struct ext4_sb_info *ext4_sb = EXT4_SB(sb); + struct mutex *inode_orphan_mutex; + spinlock_t *orphan_lock; + struct mutex *ondisk_orphan_mutex; + struct list_head *prev; + unsigned int next_inum; + struct inode *next_inode; - if (!EXT4_SB(sb)->s_journal) + if (ext4_sb->s_journal) return 0; - mutex_lock(&EXT4_SB(sb)->s_orphan_lock); - if (!list_empty(&EXT4_I(inode)->i_orphan)) + inode_orphan_mutex = &ext4_inode->i_orphan_mutex; + orphan_lock = &ext4_sb->s_orphan_lock; + ondisk_orphan_mutex = &ext4_sb->s_ondisk_orphan_lock; + mutex_lock(inode_orphan_mutex); + prev = ext4_inode->i_orphan.prev; + if (prev != &ext4_inode->i_orphan) goto out_unlock; /* @@ -2579,17 +2591,28 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode) err = ext4_reserve_inode_write(handle, inode, &iloc); if (err) goto out_unlock; + mutex_lock(ondisk_orphan_mutex); /* * 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(EXT4_SB(sb)->s_es->s_inodes_count))) + (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))) { + mutex_unlock(ondisk_orphan_mutex); goto mem_insert; + } /* Insert this inode at the head of the on-disk orphan list... */ - NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan); - EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); + next_inum = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan); + NEXT_ORPHAN(inode) = next_inum; + next_inode = ilookup(sb, next_inum); + if (next_inode) + EXT4_I(next_inode)->i_prev_orphan = inode->i_ino; + ext4_sb->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); + ext4_inode->i_prev_orphan = 0; + mutex_unlock(ondisk_orphan_mutex); + if (next_inode) + iput(next_inode); err = ext4_handle_dirty_super(handle, sb); rc = ext4_mark_iloc_dirty(handle, inode, &iloc); if (!err) @@ -2604,14 +2627,17 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode) * 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, &EXT4_SB(sb)->s_orphan); + if (!err) { + spin_lock(orphan_lock); + list_add(&ext4_inode->i_orphan, &ext4_sb->s_orphan); + spin_unlock(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(&EXT4_SB(sb)->s_orphan_lock); + mutex_unlock(inode_orphan_mutex); ext4_std_error(inode->i_sb, err); return err; } @@ -2624,71 +2650,106 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode) { struct list_head *prev; struct ext4_inode_info *ei = EXT4_I(inode); - struct ext4_sb_info *sbi; + struct inode *i_next = NULL; + struct inode *i_prev = NULL; + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); __u32 ino_next; + unsigned int ino_prev; struct ext4_iloc iloc; int err = 0; + struct mutex *inode_orphan_mutex; + spinlock_t *orphan_lock; + struct mutex *ondisk_orphan_mutex; - if ((!EXT4_SB(inode->i_sb)->s_journal) && - !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) + if ((!sbi->s_journal) && + !(sbi->s_mount_state & EXT4_ORPHAN_FS)) return 0; - mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock); - if (list_empty(&ei->i_orphan)) - goto out; - - ino_next = NEXT_ORPHAN(inode); + inode_orphan_mutex = &ei->i_orphan_mutex; + orphan_lock = &sbi->s_orphan_lock; + ondisk_orphan_mutex = &sbi->s_ondisk_orphan_lock; + mutex_lock(inode_orphan_mutex); prev = ei->i_orphan.prev; - sbi = EXT4_SB(inode->i_sb); + if (prev == &ei->i_orphan) { + mutex_unlock(inode_orphan_mutex); + return err; + } jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); + spin_lock(orphan_lock); list_del_init(&ei->i_orphan); + spin_unlock(orphan_lock); /* 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; + if (!handle) { + mutex_unlock(inode_orphan_mutex); + return err; + } err = ext4_reserve_inode_write(handle, inode, &iloc); - if (err) + if (err) { + mutex_unlock(inode_orphan_mutex); goto out_err; + } - if (prev == &sbi->s_orphan) { + mutex_lock(ondisk_orphan_mutex); + ino_next = NEXT_ORPHAN(inode); + if (ino_next > 0) { + i_next = ilookup(inode->i_sb, ino_next); + assert(i_next); + } + ino_prev = ei->i_prev_orphan; + if (!ino_prev) { 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) - goto out_brelse; - sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); - err = ext4_handle_dirty_super(handle, inode->i_sb); + if (!err) { + sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); + if (i_next) + EXT4_I(i_next)->i_prev_orphan = 0; + } + mutex_unlock(ondisk_orphan_mutex); + if (!err) + err = ext4_handle_dirty_super(handle, inode->i_sb); } else { struct ext4_iloc iloc2; - struct inode *i_prev = - &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_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) - goto out_brelse; - NEXT_ORPHAN(i_prev) = ino_next; - err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); + i_prev = ilookup(inode->i_sb, ino_prev); + + assert(i_prev); + if (i_prev) { + 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); + } else + err = -ENOENT; + if (!err) { + NEXT_ORPHAN(i_prev) = ino_next; + if (i_next) + EXT4_I(i_next)->i_prev_orphan = ino_prev; + } + mutex_unlock(ondisk_orphan_mutex); + if (i_prev && !err) + err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); } if (err) goto out_brelse; NEXT_ORPHAN(inode) = 0; + mutex_unlock(inode_orphan_mutex); err = ext4_mark_iloc_dirty(handle, inode, &iloc); - out_err: + if (i_next) + iput(i_next); + if (i_prev) + iput(i_prev); ext4_std_error(inode->i_sb, err); -out: - mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock); return err; out_brelse: + mutex_unlock(inode_orphan_mutex); brelse(iloc.bh); goto out_err; } -- 1.7.11.3