From f283c86afe6aa70b733d1ecebad5d9464943b774 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 22 Mar 2011 22:23:39 +1100 Subject: fs: remove inode_lock from iput_final and prune_icache Now that inode state changes are protected by the inode->i_lock and the inode LRU manipulations by the inode_lru_lock, we can remove the inode_lock from prune_icache and the initial part of iput_final(). instead of using the inode_lock to protect the inode during iput_final, use the inode->i_lock instead. This protects the inode against new references being taken while we change the inode state to I_FREEING, as well as preventing prune_icache from grabbing the inode while we are manipulating it. Hence we no longer need the inode_lock in iput_final prior to setting I_FREEING on the inode. For prune_icache, we no longer need the inode_lock to protect the LRU list, and the inodes themselves are protected against freeing races by the inode->i_lock. Hence we can lift the inode_lock from prune_icache as well. Signed-off-by: Dave Chinner Signed-off-by: Al Viro --- fs/inode.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) (limited to 'fs/inode.c') diff --git a/fs/inode.c b/fs/inode.c index b19cb6e..389f5a2 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -650,7 +650,6 @@ static void prune_icache(int nr_to_scan) unsigned long reap = 0; down_read(&iprune_sem); - spin_lock(&inode_lock); spin_lock(&inode_lru_lock); for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { struct inode *inode; @@ -676,8 +675,8 @@ static void prune_icache(int nr_to_scan) */ if (atomic_read(&inode->i_count) || (inode->i_state & ~I_REFERENCED)) { - spin_unlock(&inode->i_lock); list_del_init(&inode->i_lru); + spin_unlock(&inode->i_lock); inodes_stat.nr_unused--; continue; } @@ -685,20 +684,18 @@ static void prune_icache(int nr_to_scan) /* recently referenced inodes get one more pass */ if (inode->i_state & I_REFERENCED) { inode->i_state &= ~I_REFERENCED; - spin_unlock(&inode->i_lock); list_move(&inode->i_lru, &inode_lru); + spin_unlock(&inode->i_lock); continue; } if (inode_has_buffers(inode) || inode->i_data.nrpages) { __iget(inode); spin_unlock(&inode->i_lock); spin_unlock(&inode_lru_lock); - spin_unlock(&inode_lock); if (remove_inode_buffers(inode)) reap += invalidate_mapping_pages(&inode->i_data, 0, -1); iput(inode); - spin_lock(&inode_lock); spin_lock(&inode_lru_lock); if (inode != list_entry(inode_lru.next, @@ -724,7 +721,6 @@ static void prune_icache(int nr_to_scan) else __count_vm_events(PGINODESTEAL, reap); spin_unlock(&inode_lru_lock); - spin_unlock(&inode_lock); dispose_list(&freeable); up_read(&iprune_sem); @@ -1082,7 +1078,6 @@ EXPORT_SYMBOL(iunique); struct inode *igrab(struct inode *inode) { - spin_lock(&inode_lock); spin_lock(&inode->i_lock); if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) { __iget(inode); @@ -1096,7 +1091,6 @@ struct inode *igrab(struct inode *inode) */ inode = NULL; } - spin_unlock(&inode_lock); return inode; } EXPORT_SYMBOL(igrab); @@ -1439,7 +1433,6 @@ static void iput_final(struct inode *inode) const struct super_operations *op = inode->i_sb->s_op; int drop; - spin_lock(&inode->i_lock); WARN_ON(inode->i_state & I_NEW); if (op && op->drop_inode) @@ -1452,16 +1445,13 @@ static void iput_final(struct inode *inode) if (!(inode->i_state & (I_DIRTY|I_SYNC))) inode_lru_list_add(inode); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); return; } if (!drop) { inode->i_state |= I_WILL_FREE; spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); write_inode_now(inode, 1); - spin_lock(&inode_lock); spin_lock(&inode->i_lock); WARN_ON(inode->i_state & I_NEW); inode->i_state &= ~I_WILL_FREE; @@ -1470,7 +1460,6 @@ static void iput_final(struct inode *inode) inode->i_state |= I_FREEING; inode_lru_list_del(inode); spin_unlock(&inode->i_lock); - spin_unlock(&inode_lock); evict(inode); } @@ -1489,7 +1478,7 @@ void iput(struct inode *inode) if (inode) { BUG_ON(inode->i_state & I_CLEAR); - if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) + if (atomic_dec_and_lock(&inode->i_count, &inode->i_lock)) iput_final(inode); } } -- cgit v1.1