[PATCH 16/19] fs: icache remove inode_lock

From: Dave Chinner
Date: Sat Oct 16 2010 - 04:15:12 EST

From: Dave Chinner <dchinner@xxxxxxxxxx>

All the functionality that the inode_lock protected has now been
wrapped up in new independent locks and/or functionality. Hence the
inode_lock does not serve a purpose any longer and hence can now be
removed.

Based on work originally done by Nick Piggin.

Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
Documentation/filesystems/Locking | 2 +-
Documentation/filesystems/porting | 8 ++-
Documentation/filesystems/vfs.txt | 2 +-
fs/block_dev.c | 2 -
fs/buffer.c | 2 +-
fs/drop_caches.c | 4 -
fs/fs-writeback.c | 84 +++++++------------------
fs/inode.c | 125 +++++++------------------------------
fs/logfs/inode.c | 2 +-
fs/notify/inode_mark.c | 10 +--
fs/notify/mark.c | 1 -
fs/notify/vfsmount_mark.c | 1 -
fs/ntfs/inode.c | 4 +-
fs/ocfs2/inode.c | 2 +-
fs/quota/dquot.c | 12 +---
include/linux/fs.h | 2 +-
include/linux/writeback.h | 2 -
mm/backing-dev.c | 4 -
mm/filemap.c | 6 +-
mm/rmap.c | 6 +-
20 files changed, 73 insertions(+), 208 deletions(-)

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 2db4283..7f98cd5 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -114,7 +114,7 @@ alloc_inode:
destroy_inode:
dirty_inode: (must not sleep)
write_inode:
-drop_inode: !!!inode_lock!!!
+drop_inode: !!!i_lock!!!
evict_inode:
put_super: write
write_super: read
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index b12c895..f182795 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -299,7 +299,7 @@ be used instead. It gets called whenever the inode is evicted, whether it has
remaining links or not. Caller does *not* evict the pagecache or inode-associated
metadata buffers; getting rid of those is responsibility of method, as it had
been for ->delete_inode().
- ->drop_inode() returns int now; it's called on final iput() with inode_lock
+ ->drop_inode() returns int now; it's called on final iput() with i_lock
held and it returns true if filesystems wants the inode to be dropped. As before,
generic_drop_inode() is still the default and it's been updated appropriately.
generic_delete_inode() is also alive and it consists simply of return 1. Note that
@@ -318,3 +318,9 @@ if it's zero is not *and* *never* *had* *been* enough. Final unlink() and iput(
may happen while the inode is in the middle of ->write_inode(); e.g. if you blindly
free the on-disk inode, you may end up doing that while ->write_inode() is writing
to it.
+
+[mandatory]
+ The i_count field in the inode has been replaced with i_ref, which is
+a regular integer instead of an atomic_t. Filesystems should not manipulate
+it directly but use helpers like igrab(), iref() and iput().
+
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 0dbbbe4..7ab923c 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -246,7 +246,7 @@ or bottom half).
should be synchronous or not, not all filesystems check this flag.

drop_inode: called when the last access to the inode is dropped,
- with the inode_lock spinlock held.
+ with the i_lock and sb_inode_list_lock spinlock held.

This method should be either NULL (normal UNIX filesystem
semantics) or "generic_delete_inode" (for filesystems that do not
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 7909775..dae9871 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -58,14 +58,12 @@ static void bdev_inode_switch_bdi(struct inode *inode,
{
struct backing_dev_info *old = inode->i_data.backing_dev_info;

- spin_lock(&inode_lock);
bdi_lock_two(old, dst);
inode->i_data.backing_dev_info = dst;
if (!list_empty(&inode->i_wb_list))
list_move(&inode->i_wb_list, &dst->wb.b_dirty);
spin_unlock(&old->wb.b_lock);
spin_unlock(&dst->wb.b_lock);
- spin_unlock(&inode_lock);
}

static sector_t max_block(struct block_device *bdev)
diff --git a/fs/buffer.c b/fs/buffer.c
index 3e7dca2..66f7afd 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1145,7 +1145,7 @@ __getblk_slow(struct block_device *bdev, sector_t block, int size)
* inode list.
*
* mark_buffer_dirty() is atomic. It takes bh->b_page->mapping->private_lock,
- * mapping->tree_lock and the global inode_lock.
+ * and mapping->tree_lock.
*/
void mark_buffer_dirty(struct buffer_head *bh)
{
diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index f958dd8..bd39f65 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -16,7 +16,6 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused)
{
struct inode *inode, *toput_inode = NULL;

- spin_lock(&inode_lock);
spin_lock(&sb->s_inodes_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
spin_lock(&inode->i_lock);
@@ -28,15 +27,12 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused)
inode->i_ref++;
spin_unlock(&inode->i_lock);
spin_unlock(&sb->s_inodes_lock);
- spin_unlock(&inode_lock);
invalidate_mapping_pages(inode->i_mapping, 0, -1);
iput(toput_inode);
toput_inode = inode;
- spin_lock(&inode_lock);
spin_lock(&sb->s_inodes_lock);
}
spin_unlock(&sb->s_inodes_lock);
- spin_unlock(&inode_lock);
iput(toput_inode);
}

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index b75678b..5761751 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -206,7 +206,7 @@ static void requeue_io(struct inode *inode)
static void inode_sync_complete(struct inode *inode)
{
/*
- * Prevent speculative execution through spin_unlock(&inode_lock);
+ * Prevent speculative execution through spin_unlock(&inode->i_lock);
*/
smp_mb();
wake_up_bit(&inode->i_state, __I_SYNC);
@@ -306,27 +306,30 @@ 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(&inode_lock);
__wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE);
- spin_lock(&inode_lock);
spin_lock(&inode->i_lock);
}
}

-/*
- * Write out an inode's dirty pages. Called under inode_lock. Either the
- * caller has a reference on the inode or the inode has I_WILL_FREE set.
+/**
+ * sync_inode - write an inode and its pages to disk.
+ * @inode: the inode to sync
+ * @wbc: controls the writeback mode
+ *
+ * sync_inode() will write an inode and its pages to disk. It will also
+ * correctly update the inode on its superblock's dirty inode lists and will
+ * update inode->i_state.
+ *
+ * The caller must have a ref on the inode or the inode has I_WILL_FREE set.
*
- * If `wait' is set, wait on the writeout.
+ * If @wbc->sync_mode == WB_SYNC_ALL the we are doing a data integrity
+ * operation so we need to wait on the writeout.
*
* The whole writeout design is quite complex and fragile. We want to avoid
* starvation of particular inodes when others are being redirtied, prevent
* livelocks, etc.
- *
- * Called under inode_lock.
*/
-static int
-writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
+int sync_inode(struct inode *inode, struct writeback_control *wbc)
{
struct backing_dev_info *bdi = inode_to_bdi(inode);
struct address_space *mapping = inode->i_mapping;
@@ -368,7 +371,6 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
inode->i_state |= I_SYNC;
inode->i_state &= ~I_DIRTY_PAGES;
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);

ret = do_writepages(mapping, wbc);

@@ -388,12 +390,10 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
* due to delalloc, clear dirty metadata flags right before
* write_inode()
*/
- spin_lock(&inode_lock);
spin_lock(&inode->i_lock);
dirty = inode->i_state & I_DIRTY;
inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC);
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
/* Don't write the inode if only I_DIRTY_PAGES was set */
if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
int err = write_inode(inode, wbc);
@@ -401,7 +401,6 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
ret = err;
}

- spin_lock(&inode_lock);
spin_lock(&inode->i_lock);
inode->i_state &= ~I_SYNC;
if (!(inode->i_state & I_FREEING)) {
@@ -460,6 +459,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
inode_sync_complete(inode);
return ret;
}
+EXPORT_SYMBOL(sync_inode);

/*
* For background writeback the caller does not have the sb pinned
@@ -552,7 +552,7 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
spin_unlock(&wb->b_lock);

pages_skipped = wbc->pages_skipped;
- writeback_single_inode(inode, wbc);
+ sync_inode(inode, wbc);
if (wbc->pages_skipped != pages_skipped) {
/*
* writeback is not making progress due to locked
@@ -562,10 +562,8 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
redirty_tail(inode);
spin_unlock(&wb->b_lock);
}
- spin_unlock(&inode_lock);
iput(inode);
cond_resched();
- spin_lock(&inode_lock);
spin_lock(&wb->b_lock);
if (wbc->nr_to_write <= 0) {
wbc->more_io = 1;
@@ -585,9 +583,7 @@ void writeback_inodes_wb(struct bdi_writeback *wb,

if (!wbc->wb_start)
wbc->wb_start = jiffies; /* livelock avoidance */
- spin_lock(&inode_lock);
spin_lock(&wb->b_lock);
-
if (!wbc->for_kupdate || list_empty(&wb->b_io))
queue_io(wb, wbc->older_than_this);

@@ -607,7 +603,6 @@ void writeback_inodes_wb(struct bdi_writeback *wb,
break;
}
spin_unlock(&wb->b_lock);
- spin_unlock(&inode_lock);
/* Leave any unwritten inodes on b_io */
}

@@ -616,13 +611,11 @@ static void __writeback_inodes_sb(struct super_block *sb,
{
WARN_ON(!rwsem_is_locked(&sb->s_umount));

- spin_lock(&inode_lock);
spin_lock(&wb->b_lock);
if (!wbc->for_kupdate || list_empty(&wb->b_io))
queue_io(wb, wbc->older_than_this);
writeback_sb_inodes(sb, wb, wbc, true);
spin_unlock(&wb->b_lock);
- spin_unlock(&inode_lock);
}

/*
@@ -732,7 +725,6 @@ static long wb_writeback(struct bdi_writeback *wb,
* become available for writeback. Otherwise
* we'll just busyloop.
*/
- spin_lock(&inode_lock);
if (!list_empty(&wb->b_more_io)) {
spin_lock(&wb->b_lock);
inode = list_entry(wb->b_more_io.prev,
@@ -743,7 +735,6 @@ static long wb_writeback(struct bdi_writeback *wb,
inode_wait_for_writeback(inode);
spin_unlock(&inode->i_lock);
}
- spin_unlock(&inode_lock);
}

return wrote;
@@ -1006,7 +997,6 @@ void __mark_inode_dirty(struct inode *inode, int flags)
if (unlikely(block_dump))
block_dump___mark_inode_dirty(inode);

- spin_lock(&inode_lock);
spin_lock(&inode->i_lock);
if ((inode->i_state & flags) != flags) {
const int was_dirty = inode->i_state & I_DIRTY;
@@ -1064,8 +1054,6 @@ void __mark_inode_dirty(struct inode *inode, int flags)
out_unlock:
spin_unlock(&inode->i_lock);
out:
- spin_unlock(&inode_lock);
-
if (wakeup_bdi)
bdi_wakeup_thread_delayed(bdi);
}
@@ -1098,7 +1086,6 @@ static void wait_sb_inodes(struct super_block *sb)
*/
WARN_ON(!rwsem_is_locked(&sb->s_umount));

- spin_lock(&inode_lock);
spin_lock(&sb->s_inodes_lock);

/*
@@ -1121,14 +1108,12 @@ static void wait_sb_inodes(struct super_block *sb)
inode->i_ref++;
spin_unlock(&inode->i_lock);
spin_unlock(&sb->s_inodes_lock);
- spin_unlock(&inode_lock);
/*
- * We hold a reference to 'inode' so it couldn't have
- * been removed from s_inodes list while we dropped the
- * inode_lock. We cannot iput the inode now as we can
- * be holding the last reference and we cannot iput it
- * under inode_lock. So we keep the reference and iput
- * it later.
+ * We hold a reference to 'inode' so it couldn't have been
+ * removed from s_inodes list while we dropped the
+ * s_inodes_lock. We cannot iput the inode now as we can be
+ * holding the last reference and we cannot iput it under
+ * s_inodes_lock. So we keep the reference and iput it later.
*/
iput(old_inode);
old_inode = inode;
@@ -1137,11 +1122,9 @@ static void wait_sb_inodes(struct super_block *sb)

cond_resched();

- spin_lock(&inode_lock);
spin_lock(&sb->s_inodes_lock);
}
spin_unlock(&sb->s_inodes_lock);
- spin_unlock(&inode_lock);
iput(old_inode);
}

@@ -1244,33 +1227,10 @@ int write_inode_now(struct inode *inode, int sync)
wbc.nr_to_write = 0;

might_sleep();
- spin_lock(&inode_lock);
- ret = writeback_single_inode(inode, &wbc);
- spin_unlock(&inode_lock);
+ ret = sync_inode(inode, &wbc);
if (sync)
inode_sync_wait(inode);
return ret;
}
EXPORT_SYMBOL(write_inode_now);

-/**
- * sync_inode - write an inode and its pages to disk.
- * @inode: the inode to sync
- * @wbc: controls the writeback mode
- *
- * sync_inode() will write an inode and its pages to disk. It will also
- * correctly update the inode on its superblock's dirty inode lists and will
- * update inode->i_state.
- *
- * The caller must have a ref on the inode.
- */
-int sync_inode(struct inode *inode, struct writeback_control *wbc)
-{
- int ret;
-
- spin_lock(&inode_lock);
- ret = writeback_single_inode(inode, wbc);
- spin_unlock(&inode_lock);
- return ret;
-}
-EXPORT_SYMBOL(sync_inode);
diff --git a/fs/inode.c b/fs/inode.c
index 6526d70..5cddf45 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -44,24 +44,20 @@
* inode_lru, i_lru
*
* Lock orders
- * inode_lock
- * inode hash bucket lock
- * inode->i_lock
+ * inode hash bucket lock
+ * inode->i_lock
*
- * inode_lock
- * sb inode lock
- * inode_lru_lock
- * wb->b_lock
- * inode->i_lock
+ * sb inode lock
+ * inode_lru_lock
+ * wb->b_lock
+ * inode->i_lock
*
- * inode_lock
- * wb->b_lock
- * sb_lock (pin sb for writeback)
- * inode->i_lock
+ * wb->b_lock
+ * sb_lock (pin sb for writeback)
+ * inode->i_lock
*
- * inode_lock
- * inode_lru
- * inode->i_lock
+ * inode_lru
+ * inode->i_lock
*/
/*
* This is needed for the following functions:
@@ -114,14 +110,6 @@ static LIST_HEAD(inode_lru);
static DEFINE_SPINLOCK(inode_lru_lock);

/*
- * A simple spinlock to protect the list manipulations.
- *
- * NOTE! You also have to own the lock if you change
- * the i_state of an inode while it is in use..
- */
-DEFINE_SPINLOCK(inode_lock);
-
-/*
* iprune_sem provides exclusion between the kswapd or try_to_free_pages
* icache shrinking path, and the umount path. Without this exclusion,
* by the time prune_icache calls iput for the inode whose pages it has
@@ -364,11 +352,9 @@ static void init_once(void *foo)
void iref(struct inode *inode)
{
WARN_ON(inode->i_ref < 1);
- spin_lock(&inode_lock);
spin_lock(&inode->i_lock);
inode->i_ref++;
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
}
EXPORT_SYMBOL_GPL(iref);

@@ -419,22 +405,19 @@ void __insert_inode_hash(struct inode *inode, unsigned long hashval)
struct hlist_bl_head *b;

b = inode_hashtable + hash(inode->i_sb, hashval);
- spin_lock(&inode_lock);
hlist_bl_lock(b);
hlist_bl_add_head(&inode->i_hash, b);
hlist_bl_unlock(b);
- spin_unlock(&inode_lock);
}
EXPORT_SYMBOL(__insert_inode_hash);

/**
- * __remove_inode_hash - remove an inode from the hash
+ * remove_inode_hash - remove an inode from the hash
* @inode: inode to unhash
*
- * Remove an inode from the superblock. inode->i_lock must be
- * held.
+ * Remove an inode from the superblock.
*/
-static void __remove_inode_hash(struct inode *inode)
+void remove_inode_hash(struct inode *inode)
{
struct hlist_bl_head *b;

@@ -443,19 +426,6 @@ static void __remove_inode_hash(struct inode *inode)
hlist_bl_del_init(&inode->i_hash);
hlist_bl_unlock(b);
}
-
-/**
- * remove_inode_hash - remove an inode from the hash
- * @inode: inode to unhash
- *
- * Remove an inode from the superblock.
- */
-void remove_inode_hash(struct inode *inode)
-{
- spin_lock(&inode_lock);
- __remove_inode_hash(inode);
- spin_unlock(&inode_lock);
-}
EXPORT_SYMBOL(remove_inode_hash);

void end_writeback(struct inode *inode)
@@ -506,12 +476,10 @@ static void dispose_list(struct list_head *head)

evict(inode);

- spin_lock(&inode_lock);
- __remove_inode_hash(inode);
+ remove_inode_hash(inode);
spin_lock(&inode->i_sb->s_inodes_lock);
list_del_init(&inode->i_sb_list);
spin_unlock(&inode->i_sb->s_inodes_lock);
- spin_unlock(&inode_lock);

wake_up_inode(inode);
destroy_inode(inode);
@@ -538,7 +506,6 @@ static int invalidate_list(struct super_block *sb, struct list_head *head,
* change during umount anymore, and because iprune_sem keeps
* shrink_icache_memory() away.
*/
- cond_resched_lock(&inode_lock);
cond_resched_lock(&sb->s_inodes_lock);

next = next->next;
@@ -589,12 +556,10 @@ int invalidate_inodes(struct super_block *sb)
LIST_HEAD(throw_away);

down_write(&iprune_sem);
- spin_lock(&inode_lock);
spin_lock(&sb->s_inodes_lock);
fsnotify_unmount_inodes(&sb->s_inodes);
busy = invalidate_list(sb, &sb->s_inodes, &throw_away);
spin_unlock(&sb->s_inodes_lock);
- spin_unlock(&inode_lock);

dispose_list(&throw_away);
up_write(&iprune_sem);
@@ -619,7 +584,7 @@ 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 locks 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
@@ -640,7 +605,6 @@ 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;
@@ -673,12 +637,10 @@ static void prune_icache(int nr_to_scan)
inode->i_ref++;
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);
spin_lock(&inode->i_lock);

@@ -713,7 +675,6 @@ 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);
@@ -834,9 +795,9 @@ __inode_add_to_lists(struct super_block *sb, struct hlist_bl_head *b,
* @inode: inode to mark in use
*
* When an inode is allocated it needs to be accounted for, added to the in use
- * list, the owning superblock and the inode hash. This needs to be done under
- * the inode_lock, so export a function to do this rather than the inode lock
- * itself. We calculate the hash list to add to here so it is all internal
+ * list, the owning superblock and the inode hash.
+ *
+ * We calculate the hash list to add to here so it is all internal
* which requires the caller to have already set up the inode number in the
* inode to add.
*/
@@ -844,9 +805,7 @@ void inode_add_to_lists(struct super_block *sb, struct inode *inode)
{
struct hlist_bl_head *b = inode_hashtable + hash(sb, inode->i_ino);

- spin_lock(&inode_lock);
__inode_add_to_lists(sb, b, inode);
- spin_unlock(&inode_lock);
}
EXPORT_SYMBOL_GPL(inode_add_to_lists);

@@ -903,12 +862,8 @@ struct inode *new_inode(struct super_block *sb)
{
struct inode *inode;

- spin_lock_prefetch(&inode_lock);
-
inode = alloc_inode(sb);
if (inode) {
- spin_lock(&inode_lock);
-
/*
* set the inode state before we make the inode accessible to
* the outside world.
@@ -916,7 +871,6 @@ struct inode *new_inode(struct super_block *sb)
inode->i_ino = get_next_ino();
inode->i_state = 0;
__inode_add_to_lists(sb, NULL, inode);
- spin_unlock(&inode_lock);
}
return inode;
}
@@ -975,7 +929,6 @@ static struct inode *get_new_inode(struct super_block *sb,
if (inode) {
struct inode *old;

- spin_lock(&inode_lock);
/* We released the lock, so.. */
old = find_inode(sb, b, test, data);
if (!old) {
@@ -988,7 +941,6 @@ static struct inode *get_new_inode(struct super_block *sb,
*/
inode->i_state = I_NEW;
__inode_add_to_lists(sb, b, inode);
- spin_unlock(&inode_lock);

/* Return the locked inode with I_NEW set, the
* caller is responsible for filling in the contents
@@ -1003,7 +955,6 @@ static struct inode *get_new_inode(struct super_block *sb,
*/
old->i_ref++;
spin_unlock(&old->i_lock);
- spin_unlock(&inode_lock);
destroy_inode(inode);
inode = old;
wait_on_inode(inode);
@@ -1011,7 +962,6 @@ static struct inode *get_new_inode(struct super_block *sb,
return inode;

set_failed:
- spin_unlock(&inode_lock);
destroy_inode(inode);
return NULL;
}
@@ -1029,7 +979,6 @@ static struct inode *get_new_inode_fast(struct super_block *sb,
if (inode) {
struct inode *old;

- spin_lock(&inode_lock);
/* We released the lock, so.. */
old = find_inode_fast(sb, b, ino);
if (!old) {
@@ -1040,7 +989,6 @@ static struct inode *get_new_inode_fast(struct super_block *sb,
inode->i_ino = ino;
inode->i_state = I_NEW;
__inode_add_to_lists(sb, b, inode);
- spin_unlock(&inode_lock);

/* Return the locked inode with I_NEW set, the
* caller is responsible for filling in the contents
@@ -1055,7 +1003,6 @@ static struct inode *get_new_inode_fast(struct super_block *sb,
*/
old->i_ref++;
spin_unlock(&old->i_lock);
- spin_unlock(&inode_lock);
destroy_inode(inode);
inode = old;
wait_on_inode(inode);
@@ -1126,7 +1073,6 @@ 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))) {
inode->i_ref++;
@@ -1140,7 +1086,6 @@ struct inode *igrab(struct inode *inode)
*/
inode = NULL;
}
- spin_unlock(&inode_lock);
return inode;
}
EXPORT_SYMBOL(igrab);
@@ -1162,7 +1107,7 @@ EXPORT_SYMBOL(igrab);
*
* Otherwise NULL is returned.
*
- * Note, @test is called with the inode_lock held, so can't sleep.
+ * Note, @test is called with the i_lock held, so can't sleep.
*/
static struct inode *ifind(struct super_block *sb,
struct hlist_bl_head *b,
@@ -1171,17 +1116,14 @@ static struct inode *ifind(struct super_block *sb,
{
struct inode *inode;

- spin_lock(&inode_lock);
inode = find_inode(sb, b, test, data);
if (inode) {
inode->i_ref++;
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
if (likely(wait))
wait_on_inode(inode);
return inode;
}
- spin_unlock(&inode_lock);
return NULL;
}

@@ -1206,16 +1148,13 @@ static struct inode *ifind_fast(struct super_block *sb,
{
struct inode *inode;

- spin_lock(&inode_lock);
inode = find_inode_fast(sb, b, ino);
if (inode) {
inode->i_ref++;
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
wait_on_inode(inode);
return inode;
}
- spin_unlock(&inode_lock);
return NULL;
}

@@ -1238,7 +1177,7 @@ static struct inode *ifind_fast(struct super_block *sb,
*
* Otherwise NULL is returned.
*
- * Note, @test is called with the inode_lock held, so can't sleep.
+ * Note, @test is called with the i_lock held, so can't sleep.
*/
struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval,
int (*test)(struct inode *, void *), void *data)
@@ -1266,7 +1205,7 @@ EXPORT_SYMBOL(ilookup5_nowait);
*
* Otherwise NULL is returned.
*
- * Note, @test is called with the inode_lock held, so can't sleep.
+ * Note, @test is called with the i_lock held, so can't sleep.
*/
struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
int (*test)(struct inode *, void *), void *data)
@@ -1317,7 +1256,7 @@ EXPORT_SYMBOL(ilookup);
* inode and this is returned locked, hashed, and with the I_NEW flag set. The
* file system gets to fill it in before unlocking it via unlock_new_inode().
*
- * Note both @test and @set are called with the inode_lock held, so can't sleep.
+ * Note both @test and @set are called with the i_lock held, so can't sleep.
*/
struct inode *iget5_locked(struct super_block *sb, unsigned long hashval,
int (*test)(struct inode *, void *),
@@ -1378,7 +1317,6 @@ int insert_inode_locked(struct inode *inode)
while (1) {
struct hlist_bl_node *node;
struct inode *old = NULL;
- spin_lock(&inode_lock);
hlist_bl_lock(b);
hlist_bl_for_each_entry(old, node, b, i_hash) {
if (old->i_ino != ino)
@@ -1395,13 +1333,11 @@ int insert_inode_locked(struct inode *inode)
if (likely(!node)) {
hlist_bl_add_head(&inode->i_hash, b);
hlist_bl_unlock(b);
- spin_unlock(&inode_lock);
return 0;
}
old->i_ref++;
spin_unlock(&old->i_lock);
hlist_bl_unlock(b);
- spin_unlock(&inode_lock);
wait_on_inode(old);
if (unlikely(!inode_unhashed(old))) {
iput(old);
@@ -1428,7 +1364,6 @@ int insert_inode_locked4(struct inode *inode, unsigned long hashval,
struct hlist_bl_node *node;
struct inode *old = NULL;

- spin_lock(&inode_lock);
hlist_bl_lock(b);
hlist_bl_for_each_entry(old, node, b, i_hash) {
if (old->i_sb != sb)
@@ -1445,13 +1380,11 @@ int insert_inode_locked4(struct inode *inode, unsigned long hashval,
if (likely(!node)) {
hlist_bl_add_head(&inode->i_hash, b);
hlist_bl_unlock(b);
- spin_unlock(&inode_lock);
return 0;
}
old->i_ref++;
spin_unlock(&old->i_lock);
hlist_bl_unlock(b);
- spin_unlock(&inode_lock);
wait_on_inode(old);
if (unlikely(!inode_unhashed(old))) {
iput(old);
@@ -1513,16 +1446,13 @@ static void iput_final(struct inode *inode)
return;
}
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
return;
}
WARN_ON(inode->i_state & I_NEW);
inode->i_state |= I_WILL_FREE;
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
write_inode_now(inode, 1);
- spin_lock(&inode_lock);
- __remove_inode_hash(inode);
+ remove_inode_hash(inode);
spin_lock(&inode->i_lock);
WARN_ON(inode->i_state & I_NEW);
inode->i_state &= ~I_WILL_FREE;
@@ -1543,7 +1473,6 @@ static void iput_final(struct inode *inode)
list_del_init(&inode->i_sb_list);
spin_unlock(&sb->s_inodes_lock);

- spin_unlock(&inode_lock);
evict(inode);
remove_inode_hash(inode);
wake_up_inode(inode);
@@ -1563,7 +1492,6 @@ static void iput_final(struct inode *inode)
void iput(struct inode *inode)
{
if (inode) {
- spin_lock(&inode_lock);
spin_lock(&inode->i_lock);
BUG_ON(inode->i_state & I_CLEAR);

@@ -1572,7 +1500,6 @@ void iput(struct inode *inode)
return;
}
spin_unlock(&inode->i_lock);
- spin_lock(&inode_lock);
}
}
EXPORT_SYMBOL(iput);
@@ -1752,8 +1679,6 @@ EXPORT_SYMBOL(inode_wait);
* It doesn't matter if I_NEW is not set initially, a call to
* wake_up_inode() after removing from the hash list will DTRT.
*
- * This is called with inode_lock held.
- *
* Called with i_lock held and returns with it dropped.
*/
static void __wait_on_freeing_inode(struct inode *inode)
@@ -1763,10 +1688,8 @@ static void __wait_on_freeing_inode(struct inode *inode)
wq = bit_waitqueue(&inode->i_state, __I_NEW);
prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
schedule();
finish_wait(wq, &wait.wait);
- spin_lock(&inode_lock);
}

static __initdata unsigned long ihash_entries;
diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c
index d8c71ec..a67b607 100644
--- a/fs/logfs/inode.c
+++ b/fs/logfs/inode.c
@@ -286,7 +286,7 @@ static int logfs_write_inode(struct inode *inode, struct writeback_control *wbc)
return ret;
}

-/* called with inode_lock held */
+/* called with i_lock held */
static int logfs_drop_inode(struct inode *inode)
{
struct logfs_super *super = logfs_super(inode->i_sb);
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 203146b..265ecba 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -22,7 +22,6 @@
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
-#include <linux/writeback.h> /* for inode_lock */

#include <asm/atomic.h>

@@ -232,9 +231,8 @@ out:
* fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
* @list: list of inodes being unmounted (sb->s_inodes)
*
- * Called with inode_lock held, protecting the unmounting super block's list
- * of inodes, and with iprune_mutex held, keeping shrink_icache_memory() at bay.
- * We temporarily drop inode_lock, however, and CAN block.
+ * Called with iprune_mutex held, keeping shrink_icache_memory() at bay.
+ * sb->s_inodes_lock protects the super block's list of inodes.
*/
void fsnotify_unmount_inodes(struct list_head *list)
{
@@ -288,13 +286,12 @@ void fsnotify_unmount_inodes(struct list_head *list)
}

/*
- * We can safely drop inode_lock here because we hold
+ * We can safely drop sb->s_inodes_lock here because we hold
* references on both inode and next_i. Also no new inodes
* will be added since the umount has begun. Finally,
* iprune_mutex keeps shrink_icache_memory() away.
*/
spin_unlock(&sb->s_inodes_lock);
- spin_unlock(&inode_lock);

if (need_iput_tmp)
iput(need_iput_tmp);
@@ -306,7 +303,6 @@ void fsnotify_unmount_inodes(struct list_head *list)

iput(inode);

- spin_lock(&inode_lock);
spin_lock(&sb->s_inodes_lock);
}
}
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 325185e..50c0085 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -91,7 +91,6 @@
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/srcu.h>
-#include <linux/writeback.h> /* for inode_lock */

#include <asm/atomic.h>

diff --git a/fs/notify/vfsmount_mark.c b/fs/notify/vfsmount_mark.c
index 56772b5..6f8eefe 100644
--- a/fs/notify/vfsmount_mark.c
+++ b/fs/notify/vfsmount_mark.c
@@ -23,7 +23,6 @@
#include <linux/mount.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
-#include <linux/writeback.h> /* for inode_lock */

#include <asm/atomic.h>

diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index 07fdef8..9b9375a 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -54,7 +54,7 @@
*
* Return 1 if the attributes match and 0 if not.
*
- * NOTE: This function runs with the inode_lock spin lock held so it is not
+ * NOTE: This function runs with the i_lock spin lock held so it is not
* allowed to sleep.
*/
int ntfs_test_inode(struct inode *vi, ntfs_attr *na)
@@ -98,7 +98,7 @@ int ntfs_test_inode(struct inode *vi, ntfs_attr *na)
*
* Return 0 on success and -errno on error.
*
- * NOTE: This function runs with the inode_lock spin lock held so it is not
+ * NOTE: This function runs with the i_lock spin lock held so it is not
* allowed to sleep. (Hence the GFP_ATOMIC allocation.)
*/
static int ntfs_init_locked_inode(struct inode *vi, ntfs_attr *na)
diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index eece3e0..65c61e2 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -1195,7 +1195,7 @@ void ocfs2_evict_inode(struct inode *inode)
ocfs2_clear_inode(inode);
}

-/* Called under inode_lock, with no more references on the
+/* Called under i_lock, with no more references on the
* struct inode, so it's safe here to check the flags field
* and to manipulate i_nlink without any other locks. */
int ocfs2_drop_inode(struct inode *inode)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index b02a3e1..178bed4 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -76,7 +76,7 @@
#include <linux/buffer_head.h>
#include <linux/capability.h>
#include <linux/quotaops.h>
-#include <linux/writeback.h> /* for inode_lock, oddly enough.. */
+#include <linux/writeback.h>

#include <asm/uaccess.h>

@@ -896,7 +896,6 @@ static void add_dquot_ref(struct super_block *sb, int type)
int reserved = 0;
#endif

- spin_lock(&inode_lock);
spin_lock(&sb->s_inodes_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
spin_lock(&inode->i_lock);
@@ -914,21 +913,18 @@ static void add_dquot_ref(struct super_block *sb, int type)
inode->i_ref++;
spin_unlock(&inode->i_lock);
spin_unlock(&sb->s_inodes_lock);
- spin_unlock(&inode_lock);

iput(old_inode);
__dquot_initialize(inode, type);
/* We hold a reference to 'inode' so it couldn't have been
- * removed from s_inodes list while we dropped the inode_lock.
+ * removed from s_inodes list while we dropped the lock.
* We cannot iput the inode now as we can be holding the last
- * reference and we cannot iput it under inode_lock. So we
+ * reference and we cannot iput it under the lock. So we
* keep the reference and iput it later. */
old_inode = inode;
- spin_lock(&inode_lock);
spin_lock(&sb->s_inodes_lock);
}
spin_unlock(&sb->s_inodes_lock);
- spin_unlock(&inode_lock);
iput(old_inode);

#ifdef CONFIG_QUOTA_DEBUG
@@ -1009,7 +1005,6 @@ static void remove_dquot_ref(struct super_block *sb, int type,
struct inode *inode;
int reserved = 0;

- spin_lock(&inode_lock);
spin_lock(&sb->s_inodes_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
/*
@@ -1025,7 +1020,6 @@ static void remove_dquot_ref(struct super_block *sb, int type,
}
}
spin_unlock(&sb->s_inodes_lock);
- spin_unlock(&inode_lock);
#ifdef CONFIG_QUOTA_DEBUG
if (reserved) {
printk(KERN_WARNING "VFS (%s): Writes happened after quota"
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 962a606..da15124 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1593,7 +1593,7 @@ struct super_operations {
};

/*
- * Inode state bits. Protected by inode_lock.
+ * Inode state bits. Protected by i_lock.
*
* Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
* I_DIRTY_DATASYNC and I_DIRTY_PAGES.
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 242b6f8..fa38cf0 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -9,8 +9,6 @@

struct backing_dev_info;

-extern spinlock_t inode_lock;
-
/*
* fs/fs-writeback.c
*/
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 40b84c6..af060d4 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -73,7 +73,6 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v)
struct inode *inode;

nr_wb = nr_dirty = nr_io = nr_more_io = 0;
- spin_lock(&inode_lock);
spin_lock(&wb->b_lock);
list_for_each_entry(inode, &wb->b_dirty, i_wb_list)
nr_dirty++;
@@ -82,7 +81,6 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v)
list_for_each_entry(inode, &wb->b_more_io, i_wb_list)
nr_more_io++;
spin_unlock(&wb->b_lock);
- spin_unlock(&inode_lock);

global_dirty_limits(&background_thresh, &dirty_thresh);
bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh);
@@ -698,14 +696,12 @@ void bdi_destroy(struct backing_dev_info *bdi)
if (bdi_has_dirty_io(bdi)) {
struct bdi_writeback *dst = &default_backing_dev_info.wb;

- spin_lock(&inode_lock);
bdi_lock_two(bdi, &default_backing_dev_info);
list_splice(&bdi->wb.b_dirty, &dst->b_dirty);
list_splice(&bdi->wb.b_io, &dst->b_io);
list_splice(&bdi->wb.b_more_io, &dst->b_more_io);
spin_unlock(&bdi->wb.b_lock);
spin_unlock(&dst->b_lock);
- spin_unlock(&inode_lock);
}

bdi_unregister(bdi);
diff --git a/mm/filemap.c b/mm/filemap.c
index 3d4df44..ece6ef2 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -80,7 +80,7 @@
* ->i_mutex
* ->i_alloc_sem (various)
*
- * ->inode_lock
+ * ->i_lock
* ->sb_lock (fs/fs-writeback.c)
* ->mapping->tree_lock (__sync_single_inode)
*
@@ -98,8 +98,8 @@
* ->zone.lru_lock (check_pte_range->isolate_lru_page)
* ->private_lock (page_remove_rmap->set_page_dirty)
* ->tree_lock (page_remove_rmap->set_page_dirty)
- * ->inode_lock (page_remove_rmap->set_page_dirty)
- * ->inode_lock (zap_pte_range->set_page_dirty)
+ * ->i_lock (page_remove_rmap->set_page_dirty)
+ * ->i_lock (zap_pte_range->set_page_dirty)
* ->private_lock (zap_pte_range->__set_page_dirty_buffers)
*
* ->task->proc_lock
diff --git a/mm/rmap.c b/mm/rmap.c
index 92e6757..dbfccae 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -31,11 +31,11 @@
* swap_lock (in swap_duplicate, swap_info_get)
* mmlist_lock (in mmput, drain_mmlist and others)
* mapping->private_lock (in __set_page_dirty_buffers)
- * inode_lock (in set_page_dirty's __mark_inode_dirty)
- * sb_lock (within inode_lock in fs/fs-writeback.c)
+ * i_lock (in set_page_dirty's __mark_inode_dirty)
+ * sb_lock (within i_lock in fs/fs-writeback.c)
* mapping->tree_lock (widely used, in set_page_dirty,
* in arch-dependent flush_dcache_mmap_lock,
- * within inode_lock in __sync_single_inode)
+ * within i_lock in __sync_single_inode)
*
* (code doesn't rely on that order so it could be switched around)
* ->tasklist_lock
--
1.7.1

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