From f0d07b7ffde758a27a48509ceda9a9ef413e0ea0 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 3 May 2012 14:47:59 +0200 Subject: [PATCH] writeback: Remove wb->list_lock from writeback_single_inode() writeback_single_inode() doesn't need wb->list_lock for anything on entry now. So remove the requirement. This makes locking of writeback_single_inode() temporarily awkward (entering with i_lock, returning with i_lock and wb->list_lock) but it will be sanitized in the next patch. Also inode_wait_for_writeback() doesn't need wb->list_lock for anything. It was just taking it to make usage convenient for callers but with writeback_single_inode() changing it's not very convenient anymore. So remove the lock from that function. Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara Signed-off-by: Fengguang Wu --- fs/fs-writeback.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 5d3de002cb8e..3b87dc80fd30 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -328,8 +328,7 @@ static int write_inode(struct inode *inode, struct writeback_control *wbc) /* * Wait for writeback on an inode to complete. */ -static void inode_wait_for_writeback(struct inode *inode, - struct bdi_writeback *wb) +static void inode_wait_for_writeback(struct inode *inode) { DEFINE_WAIT_BIT(wq, &inode->i_state, __I_SYNC); wait_queue_head_t *wqh; @@ -337,9 +336,7 @@ static void inode_wait_for_writeback(struct inode *inode, wqh = bit_waitqueue(&inode->i_state, __I_SYNC); while (inode->i_state & I_SYNC) { spin_unlock(&inode->i_lock); - spin_unlock(&wb->list_lock); __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE); - spin_lock(&wb->list_lock); spin_lock(&inode->i_lock); } } @@ -418,7 +415,6 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, unsigned dirty; int ret; - assert_spin_locked(&wb->list_lock); assert_spin_locked(&inode->i_lock); if (!atomic_read(&inode->i_count)) @@ -432,7 +428,7 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, /* * It's a data-integrity sync. We must wait. */ - inode_wait_for_writeback(inode, wb); + inode_wait_for_writeback(inode); } BUG_ON(inode->i_state & I_SYNC); @@ -440,7 +436,6 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, /* Set I_SYNC, reset I_DIRTY_PAGES */ inode->i_state |= I_SYNC; spin_unlock(&inode->i_lock); - spin_unlock(&wb->list_lock); ret = do_writepages(mapping, wbc); @@ -587,6 +582,8 @@ static long writeback_sb_inodes(struct super_block *sb, trace_writeback_sb_inodes_requeue(inode); continue; } + spin_unlock(&wb->list_lock); + __iget(inode); write_chunk = writeback_chunk_size(wb->bdi, work); wbc.nr_to_write = write_chunk; @@ -803,8 +800,10 @@ static long wb_writeback(struct bdi_writeback *wb, trace_writeback_wait(wb->bdi, work); inode = wb_inode(wb->b_more_io.prev); spin_lock(&inode->i_lock); - inode_wait_for_writeback(inode, wb); + spin_unlock(&wb->list_lock); + inode_wait_for_writeback(inode); spin_unlock(&inode->i_lock); + spin_lock(&wb->list_lock); } } spin_unlock(&wb->list_lock); @@ -1350,7 +1349,6 @@ int write_inode_now(struct inode *inode, int sync) wbc.nr_to_write = 0; might_sleep(); - spin_lock(&wb->list_lock); spin_lock(&inode->i_lock); ret = writeback_single_inode(inode, wb, &wbc); spin_unlock(&inode->i_lock); @@ -1375,7 +1373,6 @@ int sync_inode(struct inode *inode, struct writeback_control *wbc) struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; int ret; - spin_lock(&wb->list_lock); spin_lock(&inode->i_lock); ret = writeback_single_inode(inode, wb, wbc); spin_unlock(&inode->i_lock);