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authorNick Piggin <npiggin@suse.de>2010-10-21 11:49:30 +1100
committerAl Viro <viro@zeniv.linux.org.uk>2010-10-25 21:26:15 -0400
commit7ccf19a8042e343f8159f8a5fdd6a9422aa90c78 (patch)
tree9a69aaad6eb8992cae06f44dfea8c1d94f2a7f99 /fs/inode.c
parenta5491e0c7bb7387e3e6ff9994d6dc2efc78af56c (diff)
fs: inode split IO and LRU lists
The use of the same inode list structure (inode->i_list) for two different list constructs with different lifecycles and purposes makes it impossible to separate the locking of the different operations. Therefore, to enable the separation of the locking of the writeback and reclaim lists, split the inode->i_list into two separate lists dedicated to their specific tracking functions. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/inode.c')
-rw-r--r--fs/inode.c53
1 files changed, 34 insertions, 19 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 4bedac32154..09e2d7a5f1d 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -71,7 +71,7 @@ static unsigned int i_hash_shift __read_mostly;
* allowing for low-overhead inode sync() operations.
*/
-static LIST_HEAD(inode_unused);
+static LIST_HEAD(inode_lru);
static struct hlist_head *inode_hashtable __read_mostly;
/*
@@ -271,6 +271,7 @@ EXPORT_SYMBOL(__destroy_inode);
static void destroy_inode(struct inode *inode)
{
+ BUG_ON(!list_empty(&inode->i_lru));
__destroy_inode(inode);
if (inode->i_sb->s_op->destroy_inode)
inode->i_sb->s_op->destroy_inode(inode);
@@ -289,7 +290,8 @@ void inode_init_once(struct inode *inode)
INIT_HLIST_NODE(&inode->i_hash);
INIT_LIST_HEAD(&inode->i_dentry);
INIT_LIST_HEAD(&inode->i_devices);
- INIT_LIST_HEAD(&inode->i_list);
+ INIT_LIST_HEAD(&inode->i_wb_list);
+ INIT_LIST_HEAD(&inode->i_lru);
INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
spin_lock_init(&inode->i_data.tree_lock);
spin_lock_init(&inode->i_data.i_mmap_lock);
@@ -330,16 +332,16 @@ EXPORT_SYMBOL(ihold);
static void inode_lru_list_add(struct inode *inode)
{
- if (list_empty(&inode->i_list)) {
- list_add(&inode->i_list, &inode_unused);
+ if (list_empty(&inode->i_lru)) {
+ list_add(&inode->i_lru, &inode_lru);
percpu_counter_inc(&nr_inodes_unused);
}
}
static void inode_lru_list_del(struct inode *inode)
{
- if (!list_empty(&inode->i_list)) {
- list_del_init(&inode->i_list);
+ if (!list_empty(&inode->i_lru)) {
+ list_del_init(&inode->i_lru);
percpu_counter_dec(&nr_inodes_unused);
}
}
@@ -460,8 +462,8 @@ static void dispose_list(struct list_head *head)
while (!list_empty(head)) {
struct inode *inode;
- inode = list_first_entry(head, struct inode, i_list);
- list_del_init(&inode->i_list);
+ inode = list_first_entry(head, struct inode, i_lru);
+ list_del_init(&inode->i_lru);
evict(inode);
@@ -507,8 +509,14 @@ static int invalidate_list(struct list_head *head, struct list_head *dispose)
continue;
}
- list_move(&inode->i_list, dispose);
inode->i_state |= I_FREEING;
+
+ /*
+ * Move the inode off the IO lists and LRU once I_FREEING is
+ * set so that it won't get moved back on there if it is dirty.
+ */
+ list_move(&inode->i_lru, dispose);
+ list_del_init(&inode->i_wb_list);
if (!(inode->i_state & (I_DIRTY | I_SYNC)))
percpu_counter_dec(&nr_inodes_unused);
}
@@ -580,10 +588,10 @@ static void prune_icache(int nr_to_scan)
for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) {
struct inode *inode;
- if (list_empty(&inode_unused))
+ if (list_empty(&inode_lru))
break;
- inode = list_entry(inode_unused.prev, struct inode, i_list);
+ inode = list_entry(inode_lru.prev, struct inode, i_lru);
/*
* Referenced or dirty inodes are still in use. Give them
@@ -591,14 +599,14 @@ static void prune_icache(int nr_to_scan)
*/
if (atomic_read(&inode->i_count) ||
(inode->i_state & ~I_REFERENCED)) {
- list_del_init(&inode->i_list);
+ list_del_init(&inode->i_lru);
percpu_counter_dec(&nr_inodes_unused);
continue;
}
/* recently referenced inodes get one more pass */
if (inode->i_state & I_REFERENCED) {
- list_move(&inode->i_list, &inode_unused);
+ list_move(&inode->i_lru, &inode_lru);
inode->i_state &= ~I_REFERENCED;
continue;
}
@@ -611,15 +619,21 @@ static void prune_icache(int nr_to_scan)
iput(inode);
spin_lock(&inode_lock);
- if (inode != list_entry(inode_unused.next,
- struct inode, i_list))
+ if (inode != list_entry(inode_lru.next,
+ struct inode, i_lru))
continue; /* wrong inode or list_empty */
if (!can_unuse(inode))
continue;
}
- list_move(&inode->i_list, &freeable);
WARN_ON(inode->i_state & I_NEW);
inode->i_state |= I_FREEING;
+
+ /*
+ * Move the inode off the IO lists and LRU once I_FREEING is
+ * set so that it won't get moved back on there if it is dirty.
+ */
+ list_move(&inode->i_lru, &freeable);
+ list_del_init(&inode->i_wb_list);
percpu_counter_dec(&nr_inodes_unused);
}
if (current_is_kswapd())
@@ -1340,15 +1354,16 @@ static void iput_final(struct inode *inode)
inode->i_state &= ~I_WILL_FREE;
__remove_inode_hash(inode);
}
+
WARN_ON(inode->i_state & I_NEW);
inode->i_state |= I_FREEING;
/*
- * After we delete the inode from the LRU here, we avoid moving dirty
- * inodes back onto the LRU now because I_FREEING is set and hence
- * writeback_single_inode() won't move the inode around.
+ * Move the inode off the IO lists and LRU once I_FREEING is
+ * set so that it won't get moved back on there if it is dirty.
*/
inode_lru_list_del(inode);
+ list_del_init(&inode->i_wb_list);
__inode_sb_list_del(inode);
spin_unlock(&inode_lock);