diff options
| -rw-r--r-- | fs/inode.c | 39 |
1 files changed, 30 insertions, 9 deletions
diff --git a/fs/inode.c b/fs/inode.c index f752a959254..b19cb6ee6ca 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -32,10 +32,13 @@ * * inode->i_lock protects: * inode->i_state, inode->i_hash, __iget() + * inode_lru_lock protects: + * inode_lru, inode->i_lru * * Lock ordering: * inode_lock * inode->i_lock + * inode_lru_lock */ /* @@ -85,6 +88,7 @@ static unsigned int i_hash_shift __read_mostly; */ static LIST_HEAD(inode_lru); +static DEFINE_SPINLOCK(inode_lru_lock); static struct hlist_head *inode_hashtable __read_mostly; /* @@ -356,18 +360,22 @@ EXPORT_SYMBOL(ihold); static void inode_lru_list_add(struct inode *inode) { + spin_lock(&inode_lru_lock); if (list_empty(&inode->i_lru)) { list_add(&inode->i_lru, &inode_lru); inodes_stat.nr_unused++; } + spin_unlock(&inode_lru_lock); } static void inode_lru_list_del(struct inode *inode) { + spin_lock(&inode_lru_lock); if (!list_empty(&inode->i_lru)) { list_del_init(&inode->i_lru); inodes_stat.nr_unused--; } + spin_unlock(&inode_lru_lock); } static inline void __inode_sb_list_add(struct inode *inode) @@ -543,10 +551,9 @@ void evict_inodes(struct super_block *sb) } inode->i_state |= I_FREEING; - if (!(inode->i_state & (I_DIRTY | I_SYNC))) - inodes_stat.nr_unused--; + inode_lru_list_del(inode); spin_unlock(&inode->i_lock); - list_move(&inode->i_lru, &dispose); + list_add(&inode->i_lru, &dispose); } spin_unlock(&inode_lock); @@ -596,10 +603,9 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty) } inode->i_state |= I_FREEING; - if (!(inode->i_state & (I_DIRTY | I_SYNC))) - inodes_stat.nr_unused--; + inode_lru_list_del(inode); spin_unlock(&inode->i_lock); - list_move(&inode->i_lru, &dispose); + list_add(&inode->i_lru, &dispose); } spin_unlock(&inode_lock); @@ -623,7 +629,7 @@ static int can_unuse(struct inode *inode) /* * Scan `goal' inodes on the unused list for freeable ones. They are moved to a - * temporary list and then are freed outside inode_lock by dispose_list(). + * temporary list and then are freed outside inode_lru_lock by dispose_list(). * * Any inodes which are pinned purely because of attached pagecache have their * pagecache removed. If the inode has metadata buffers attached to @@ -645,6 +651,7 @@ static void prune_icache(int nr_to_scan) 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; @@ -654,10 +661,19 @@ static void prune_icache(int nr_to_scan) inode = list_entry(inode_lru.prev, struct inode, i_lru); /* + * we are inverting the inode_lru_lock/inode->i_lock here, + * so use a trylock. If we fail to get the lock, just move the + * inode to the back of the list so we don't spin on it. + */ + if (!spin_trylock(&inode->i_lock)) { + list_move(&inode->i_lru, &inode_lru); + continue; + } + + /* * Referenced or dirty inodes are still in use. Give them * another pass through the LRU as we canot reclaim them now. */ - spin_lock(&inode->i_lock); if (atomic_read(&inode->i_count) || (inode->i_state & ~I_REFERENCED)) { spin_unlock(&inode->i_lock); @@ -676,17 +692,21 @@ static void prune_icache(int nr_to_scan) 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, struct inode, i_lru)) continue; /* wrong inode or list_empty */ - spin_lock(&inode->i_lock); + /* avoid lock inversions with trylock */ + if (!spin_trylock(&inode->i_lock)) + continue; if (!can_unuse(inode)) { spin_unlock(&inode->i_lock); continue; @@ -703,6 +723,7 @@ static void prune_icache(int nr_to_scan) __count_vm_events(KSWAPD_INODESTEAL, reap); else __count_vm_events(PGINODESTEAL, reap); + spin_unlock(&inode_lru_lock); spin_unlock(&inode_lock); dispose_list(&freeable); |