From 0f1b1fd86f6fd662e04da3e82a6780b226fcd0d1 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 22 Mar 2011 22:23:43 +1100 Subject: fs: pull inode->i_lock up out of writeback_single_inode First thing we do in writeback_single_inode() is take the i_lock and the last thing we do is drop it. A caller already holds the i_lock, so pull the i_lock out of writeback_single_inode() to reduce the round trips on this lock during inode writeback. Signed-off-by: Dave Chinner Signed-off-by: Al Viro --- fs/fs-writeback.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index ed800656356b..b5ed541fb137 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -332,9 +332,9 @@ static void inode_wait_for_writeback(struct inode *inode) } /* - * Write out an inode's dirty pages. Called under inode_wb_list_lock. Either - * the caller has an active reference on the inode or the inode has I_WILL_FREE - * set. + * Write out an inode's dirty pages. Called under inode_wb_list_lock and + * inode->i_lock. Either the caller has an active reference on the inode or + * the inode has I_WILL_FREE set. * * If `wait' is set, wait on the writeout. * @@ -349,7 +349,9 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) unsigned dirty; int ret; - spin_lock(&inode->i_lock); + assert_spin_locked(&inode_wb_list_lock); + assert_spin_locked(&inode->i_lock); + if (!atomic_read(&inode->i_count)) WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING))); else @@ -365,7 +367,6 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * completed a full scan of b_io. */ if (wbc->sync_mode != WB_SYNC_ALL) { - spin_unlock(&inode->i_lock); requeue_io(inode); return 0; } @@ -456,7 +457,6 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) } } inode_sync_complete(inode); - spin_unlock(&inode->i_lock); return ret; } @@ -544,7 +544,6 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, } __iget(inode); - spin_unlock(&inode->i_lock); pages_skipped = wbc->pages_skipped; writeback_single_inode(inode, wbc); @@ -555,6 +554,7 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, */ redirty_tail(inode); } + spin_unlock(&inode->i_lock); spin_unlock(&inode_wb_list_lock); iput(inode); cond_resched(); @@ -1309,7 +1309,9 @@ int write_inode_now(struct inode *inode, int sync) might_sleep(); spin_lock(&inode_wb_list_lock); + spin_lock(&inode->i_lock); ret = writeback_single_inode(inode, &wbc); + spin_unlock(&inode->i_lock); spin_unlock(&inode_wb_list_lock); if (sync) inode_sync_wait(inode); @@ -1333,7 +1335,9 @@ int sync_inode(struct inode *inode, struct writeback_control *wbc) int ret; spin_lock(&inode_wb_list_lock); + spin_lock(&inode->i_lock); ret = writeback_single_inode(inode, wbc); + spin_unlock(&inode->i_lock); spin_unlock(&inode_wb_list_lock); return ret; } -- cgit v1.2.3