* [PATCH 1/3] fs: move i_sb_list out from under inode_lock
2010-10-28 11:42 [PATCH 0/3] fs: peel back the inode_lock some more Dave Chinner
@ 2010-10-28 11:42 ` Dave Chinner
2010-10-28 14:11 ` Christoph Hellwig
2010-10-28 11:42 ` [PATCH 2/3] fs: move i_wb_list " Dave Chinner
` (2 subsequent siblings)
3 siblings, 1 reply; 9+ messages in thread
From: Dave Chinner @ 2010-10-28 11:42 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel
From: Dave Chinner <dchinner@redhat.com>
Protect the per-sb inode list with a new global lock
inode_sb_list_lock and use it to protect the list manipulations and
traversals. This lock replaces the inode_lock as the inodes on the
list can be validity checked while holding the inode->i_lock and
hence the inode_lock is no longer needed to protect the list.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/drop_caches.c | 9 +++++----
fs/fs-writeback.c | 21 +++++++++++----------
fs/inode.c | 43 +++++++++++++++++++++++--------------------
fs/internal.h | 2 ++
fs/notify/inode_mark.c | 15 ++++++++-------
fs/quota/dquot.c | 28 ++++++++++++++++------------
6 files changed, 65 insertions(+), 53 deletions(-)
diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index 62dd8ee..86cd2f1 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -8,6 +8,7 @@
#include <linux/writeback.h>
#include <linux/sysctl.h>
#include <linux/gfp.h>
+#include "internal.h"
/* A global variable is a bit ugly, but it keeps the code simple */
int sysctl_drop_caches;
@@ -16,7 +17,7 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused)
{
struct inode *inode, *toput_inode = NULL;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
spin_lock(&inode->i_lock);
if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
@@ -26,13 +27,13 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused)
}
__iget(inode);
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
invalidate_mapping_pages(inode->i_mapping, 0, -1);
iput(toput_inode);
toput_inode = inode;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
iput(toput_inode);
}
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 50de4f1..7707a62 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1053,7 +1053,7 @@ static void wait_sb_inodes(struct super_block *sb)
*/
WARN_ON(!rwsem_is_locked(&sb->s_umount));
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
/*
* Data integrity sync. Must wait for all pages under writeback,
@@ -1073,14 +1073,15 @@ static void wait_sb_inodes(struct super_block *sb)
}
__iget(inode);
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_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
+ * inode_sb_list_lock. We cannot iput the inode now as we can
+ * be holding the last reference and we cannot iput it under
+ * inode_sb_list_lock. So we keep the reference and iput it
+ * later.
*/
iput(old_inode);
old_inode = inode;
@@ -1089,9 +1090,9 @@ static void wait_sb_inodes(struct super_block *sb)
cond_resched();
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
iput(old_inode);
}
diff --git a/fs/inode.c b/fs/inode.c
index f64aeda..44f28dd 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -32,10 +32,15 @@
* inode->i_state, __iget()
* inode_lru_lock protects:
* inode_lru, inode->i_lru
+ * inode_sb_list_lock protects:
+ * sb->s_inodes, inode->i_sb_list
*
* Lock ordering:
* inode_lock
* inode->i_lock
+ *
+ * inode_sb_list_lock
+ * inode->i_lock
* inode_lru_lock
*/
@@ -97,6 +102,8 @@ static struct hlist_head *inode_hashtable __read_mostly;
*/
DEFINE_SPINLOCK(inode_lock);
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock);
+
/*
* iprune_sem provides exclusion between the kswapd or try_to_free_pages
* icache shrinking path, and the umount path. Without this exclusion,
@@ -365,26 +372,23 @@ static void inode_lru_list_del(struct inode *inode)
spin_unlock(&inode_lru_lock);
}
-static inline void __inode_sb_list_add(struct inode *inode)
-{
- list_add(&inode->i_sb_list, &inode->i_sb->s_inodes);
-}
-
/**
* inode_sb_list_add - add inode to the superblock list of inodes
* @inode: inode to add
*/
void inode_sb_list_add(struct inode *inode)
{
- spin_lock(&inode_lock);
- __inode_sb_list_add(inode);
- spin_unlock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
+ list_add(&inode->i_sb_list, &inode->i_sb->s_inodes);
+ spin_unlock(&inode_sb_list_lock);
}
EXPORT_SYMBOL_GPL(inode_sb_list_add);
-static inline void __inode_sb_list_del(struct inode *inode)
+static inline void inode_sb_list_del(struct inode *inode)
{
+ spin_lock(&inode_sb_list_lock);
list_del_init(&inode->i_sb_list);
+ spin_unlock(&inode_sb_list_lock);
}
static unsigned long hash(struct super_block *sb, unsigned long hashval)
@@ -460,9 +464,10 @@ static void evict(struct inode *inode)
spin_lock(&inode_lock);
list_del_init(&inode->i_wb_list);
- __inode_sb_list_del(inode);
spin_unlock(&inode_lock);
+ inode_sb_list_del(inode);
+
if (op->evict_inode) {
op->evict_inode(inode);
} else {
@@ -516,7 +521,7 @@ void evict_inodes(struct super_block *sb)
down_write(&iprune_sem);
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
if (atomic_read(&inode->i_count))
continue;
@@ -534,7 +539,7 @@ void evict_inodes(struct super_block *sb)
list_add(&inode->i_lru, &dispose);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
dispose_list(&dispose);
up_write(&iprune_sem);
@@ -555,7 +560,7 @@ int invalidate_inodes(struct super_block *sb)
down_write(&iprune_sem);
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
spin_lock(&inode->i_lock);
if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) {
@@ -574,7 +579,7 @@ int invalidate_inodes(struct super_block *sb)
list_add(&inode->i_lru, &dispose);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
dispose_list(&dispose);
up_write(&iprune_sem);
@@ -839,16 +844,14 @@ struct inode *new_inode(struct super_block *sb)
{
struct inode *inode;
- spin_lock_prefetch(&inode_lock);
+ spin_lock_prefetch(&inode_sb_list_lock);
inode = alloc_inode(sb);
if (inode) {
- spin_lock(&inode_lock);
spin_lock(&inode->i_lock);
inode->i_state = 0;
spin_unlock(&inode->i_lock);
- __inode_sb_list_add(inode);
- spin_unlock(&inode_lock);
+ inode_sb_list_add(inode);
}
return inode;
}
@@ -918,7 +921,7 @@ static struct inode *get_new_inode(struct super_block *sb,
inode->i_state = I_NEW;
spin_unlock(&inode->i_lock);
hlist_add_head(&inode->i_hash, head);
- __inode_sb_list_add(inode);
+ inode_sb_list_add(inode);
spin_unlock(&inode_lock);
/* Return the locked inode with I_NEW set, the
@@ -967,7 +970,7 @@ static struct inode *get_new_inode_fast(struct super_block *sb,
inode->i_state = I_NEW;
spin_unlock(&inode->i_lock);
hlist_add_head(&inode->i_hash, head);
- __inode_sb_list_add(inode);
+ inode_sb_list_add(inode);
spin_unlock(&inode_lock);
/* Return the locked inode with I_NEW set, the
diff --git a/fs/internal.h b/fs/internal.h
index ebad3b9..493baa1 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -108,3 +108,5 @@ extern void release_open_intent(struct nameidata *);
extern int get_nr_dirty_inodes(void);
extern int evict_inodes(struct super_block *);
extern int invalidate_inodes(struct super_block *);
+
+extern spinlock_t inode_sb_list_lock;
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 9c0fb09..06c8216 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -29,6 +29,8 @@
#include <linux/fsnotify_backend.h>
#include "fsnotify.h"
+#include "../internal.h"
+
/*
* Recalculate the mask of events relevant to a given inode locked.
*/
@@ -232,15 +234,14 @@ 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 during unmount with no locks held, so needs to be safe against
+ * concurrent modifiers. We temporarily drop inode_sb_list_lock and CAN block.
*/
void fsnotify_unmount_inodes(struct list_head *list)
{
struct inode *inode, *next_i, *need_iput = NULL;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry_safe(inode, next_i, list, i_sb_list) {
struct inode *need_iput_tmp;
@@ -293,7 +294,7 @@ void fsnotify_unmount_inodes(struct list_head *list)
* will be added since the umount has begun. Finally,
* iprune_mutex keeps shrink_icache_memory() away.
*/
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
if (need_iput_tmp)
iput(need_iput_tmp);
@@ -305,7 +306,7 @@ void fsnotify_unmount_inodes(struct list_head *list)
iput(inode);
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
}
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index a2d89f8..440f64c 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 "../internal.h" /* ugh */
#include <asm/uaccess.h>
@@ -896,7 +896,7 @@ static void add_dquot_ref(struct super_block *sb, int type)
int reserved = 0;
#endif
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
spin_lock(&inode->i_lock);
if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
@@ -911,19 +911,23 @@ static void add_dquot_ref(struct super_block *sb, int type)
#endif
__iget(inode);
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_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.
- * 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
+ * inode_sb_list_lock We cannot iput the inode now as we can be
+ * holding the last reference and we cannot iput it under
+ * inode_sb_list_lock. So we keep the reference and iput it
+ * later.
+ */
old_inode = inode;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
iput(old_inode);
#ifdef CONFIG_QUOTA_DEBUG
@@ -1004,7 +1008,7 @@ static void remove_dquot_ref(struct super_block *sb, int type,
struct inode *inode;
int reserved = 0;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
/*
* We have to scan also I_NEW inodes because they can already
@@ -1018,7 +1022,7 @@ static void remove_dquot_ref(struct super_block *sb, int type,
remove_inode_dquot_ref(inode, type, tofree_head);
}
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
#ifdef CONFIG_QUOTA_DEBUG
if (reserved) {
printk(KERN_WARNING "VFS (%s): Writes happened after quota"
--
1.7.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH 2/3] fs: move i_wb_list out from under inode_lock
2010-10-28 11:42 [PATCH 0/3] fs: peel back the inode_lock some more Dave Chinner
2010-10-28 11:42 ` [PATCH 1/3] fs: move i_sb_list out from under inode_lock Dave Chinner
@ 2010-10-28 11:42 ` Dave Chinner
2010-10-28 14:19 ` Christoph Hellwig
2010-10-28 11:42 ` [PATCH 3/3] fs: move i_hash " Dave Chinner
2010-10-28 12:00 ` [PATCH 0/3] fs: peel back the inode_lock some more Christoph Hellwig
3 siblings, 1 reply; 9+ messages in thread
From: Dave Chinner @ 2010-10-28 11:42 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel
From: Dave Chinner <dchinner@redhat.com>
Protect the inode writeback list with a new global lock
inode_wb_list_lock and use it to protect the list manipulations and
traversals. This lock replaces the inode_lock as the inodes on the
list can be validity checked while holding the inode->i_lock and
hence the inode_lock is no longer needed to protect the list.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/block_dev.c | 4 +-
fs/fs-writeback.c | 152 ++++++++++++++++++++++++---------------------
fs/inode.c | 12 +++-
fs/internal.h | 7 ++-
include/linux/writeback.h | 1 +
mm/backing-dev.c | 8 +-
6 files changed, 103 insertions(+), 81 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index dea3b62..a94cbf0 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -56,11 +56,11 @@ EXPORT_SYMBOL(I_BDEV);
static void bdev_inode_switch_bdi(struct inode *inode,
struct backing_dev_info *dst)
{
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
inode->i_data.backing_dev_info = dst;
if (inode->i_state & I_DIRTY)
list_move(&inode->i_wb_list, &dst->wb.b_dirty);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
}
static sector_t max_block(struct block_device *bdev)
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 7707a62..5b7cb95 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -162,6 +162,17 @@ void bdi_start_background_writeback(struct backing_dev_info *bdi)
}
/*
+ * Remove the inode from the writeback list it is on.
+ */
+void inode_wb_list_del(struct inode *inode)
+{
+ spin_lock(&inode_wb_list_lock);
+ list_del_init(&inode->i_wb_list);
+ spin_unlock(&inode_wb_list_lock);
+}
+
+
+/*
* Redirty an inode: set its when-it-was dirtied timestamp and move it to the
* furthest end of its superblock's dirty-inode list.
*
@@ -174,6 +185,7 @@ static void redirty_tail(struct inode *inode)
{
struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
+ assert_spin_locked(&inode_wb_list_lock);
if (!list_empty(&wb->b_dirty)) {
struct inode *tail;
@@ -191,14 +203,17 @@ static void requeue_io(struct inode *inode)
{
struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
+ assert_spin_locked(&inode_wb_list_lock);
list_move(&inode->i_wb_list, &wb->b_more_io);
}
static void inode_sync_complete(struct inode *inode)
{
/*
- * Prevent speculative execution through spin_unlock(&inode_lock);
+ * Prevent speculative execution through
+ * spin_unlock(&inode_wb_list_lock);
*/
+
smp_mb();
wake_up_bit(&inode->i_state, __I_SYNC);
}
@@ -272,6 +287,7 @@ static void move_expired_inodes(struct list_head *delaying_queue,
*/
static void queue_io(struct bdi_writeback *wb, unsigned long *older_than_this)
{
+ assert_spin_locked(&inode_wb_list_lock);
list_splice_init(&wb->b_more_io, &wb->b_io);
move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this);
}
@@ -294,25 +310,23 @@ 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);
+ spin_unlock(&inode_wb_list_lock);
__wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE);
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
spin_lock(&inode->i_lock);
}
}
/*
- * Write out an inode's dirty pages. Called under inode_lock. Either the
- * caller has ref on the inode (either via __iget or via syscall against an fd)
- * or the inode has I_WILL_FREE set (via generic_forget_inode)
+ * Write out an inode's dirty pages. Called under inode_wb_list_lock. Either
+ * the caller has ref on the inode (either via __iget or via syscall against an
+ * fd) or the inode has I_WILL_FREE set.
*
* If `wait' is set, 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)
@@ -354,7 +368,7 @@ 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);
+ spin_unlock(&inode_wb_list_lock);
ret = do_writepages(mapping, wbc);
@@ -374,12 +388,10 @@ 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);
@@ -387,7 +399,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
ret = err;
}
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
spin_lock(&inode->i_lock);
inode->i_state &= ~I_SYNC;
if (!(inode->i_state & I_FREEING)) {
@@ -529,10 +541,10 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
*/
redirty_tail(inode);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
iput(inode);
cond_resched();
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
if (wbc->nr_to_write <= 0) {
wbc->more_io = 1;
return 1;
@@ -551,7 +563,7 @@ void writeback_inodes_wb(struct bdi_writeback *wb,
if (!wbc->wb_start)
wbc->wb_start = jiffies; /* livelock avoidance */
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
if (!wbc->for_kupdate || list_empty(&wb->b_io))
queue_io(wb, wbc->older_than_this);
@@ -569,7 +581,7 @@ void writeback_inodes_wb(struct bdi_writeback *wb,
if (ret)
break;
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
/* Leave any unwritten inodes on b_io */
}
@@ -578,11 +590,11 @@ static void __writeback_inodes_sb(struct super_block *sb,
{
WARN_ON(!rwsem_is_locked(&sb->s_umount));
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_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(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
}
/*
@@ -692,7 +704,7 @@ static long wb_writeback(struct bdi_writeback *wb,
* become available for writeback. Otherwise
* we'll just busyloop.
*/
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
if (!list_empty(&wb->b_more_io)) {
inode = wb_inode(wb->b_more_io.prev);
trace_wbc_writeback_wait(&wbc, wb->bdi);
@@ -700,7 +712,7 @@ static long wb_writeback(struct bdi_writeback *wb,
inode_wait_for_writeback(inode);
spin_unlock(&inode->i_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
}
return wrote;
@@ -940,6 +952,7 @@ void __mark_inode_dirty(struct inode *inode, int flags)
struct super_block *sb = inode->i_sb;
struct backing_dev_info *bdi = NULL;
bool wakeup_bdi = false;
+ int was_dirty;
/*
* Don't do this for I_DIRTY_PAGES - that doesn't actually
@@ -963,63 +976,62 @@ 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;
+ if ((inode->i_state & flags) == flags)
+ goto out_unlock_inode;
- inode->i_state |= flags;
+ was_dirty = inode->i_state & I_DIRTY;
+ inode->i_state |= flags;
- /*
- * If the inode is being synced, just update its dirty state.
- * The unlocker will place the inode on the appropriate
- * superblock list, based upon its state.
- */
- if (inode->i_state & I_SYNC)
- goto out_unlock_inode;
+ /*
+ * If the inode is being synced, just update its dirty state.
+ * The unlocker will place the inode on the appropriate
+ * superblock list, based upon its state.
+ */
+ if (inode->i_state & I_SYNC)
+ goto out_unlock_inode;
- /*
- * Only add valid (hashed) inodes to the superblock's
- * dirty list. Add blockdev inodes as well.
- */
- if (!S_ISBLK(inode->i_mode)) {
- if (inode_unhashed(inode))
- goto out_unlock_inode;
- }
- if (inode->i_state & I_FREEING)
+ /*
+ * Only add valid (hashed) inodes to the superblock's
+ * dirty list. Add blockdev inodes as well.
+ */
+ if (!S_ISBLK(inode->i_mode)) {
+ if (inode_unhashed(inode))
goto out_unlock_inode;
+ }
+ if (inode->i_state & I_FREEING)
+ goto out_unlock_inode;
+ /*
+ * If the inode was already on b_dirty/b_io/b_more_io, don't
+ * reposition it (that would break b_dirty time-ordering).
+ */
+ if (was_dirty) {
+out_unlock_inode:
spin_unlock(&inode->i_lock);
- /*
- * If the inode was already on b_dirty/b_io/b_more_io, don't
- * reposition it (that would break b_dirty time-ordering).
- */
- if (!was_dirty) {
- bdi = inode_to_bdi(inode);
+ return;
+ }
- if (bdi_cap_writeback_dirty(bdi)) {
- WARN(!test_bit(BDI_registered, &bdi->state),
- "bdi-%s not registered\n", bdi->name);
+ spin_unlock(&inode->i_lock);
+ bdi = inode_to_bdi(inode);
- /*
- * If this is the first dirty inode for this
- * bdi, we have to wake-up the corresponding
- * bdi thread to make sure background
- * write-back happens later.
- */
- if (!wb_has_dirty_io(&bdi->wb))
- wakeup_bdi = true;
- }
+ if (bdi_cap_writeback_dirty(bdi)) {
+ WARN(!test_bit(BDI_registered, &bdi->state),
+ "bdi-%s not registered\n", bdi->name);
- inode->dirtied_when = jiffies;
- list_move(&inode->i_wb_list, &bdi->wb.b_dirty);
- }
- goto out;
+ /*
+ * If this is the first dirty inode for this bdi, we have to
+ * wake-up the corresponding bdi thread to make sure background
+ * write-back happens later.
+ */
+ if (!wb_has_dirty_io(&bdi->wb))
+ wakeup_bdi = true;
}
-out_unlock_inode:
- spin_unlock(&inode->i_lock);
-out:
- spin_unlock(&inode_lock);
+
+ spin_lock(&inode_wb_list_lock);
+ inode->dirtied_when = jiffies;
+ list_move(&inode->i_wb_list, &bdi->wb.b_dirty);
+ spin_unlock(&inode_wb_list_lock);
if (wakeup_bdi)
bdi_wakeup_thread_delayed(bdi);
@@ -1195,9 +1207,9 @@ int write_inode_now(struct inode *inode, int sync)
wbc.nr_to_write = 0;
might_sleep();
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
ret = writeback_single_inode(inode, &wbc);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
if (sync)
inode_sync_wait(inode);
return ret;
@@ -1219,9 +1231,9 @@ int sync_inode(struct inode *inode, struct writeback_control *wbc)
{
int ret;
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
ret = writeback_single_inode(inode, wbc);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
return ret;
}
EXPORT_SYMBOL(sync_inode);
diff --git a/fs/inode.c b/fs/inode.c
index 44f28dd..130aa74 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -24,6 +24,7 @@
#include <linux/mount.h>
#include <linux/async.h>
#include <linux/posix_acl.h>
+#include "internal.h"
/*
* inode locking rules.
@@ -34,6 +35,8 @@
* inode_lru, inode->i_lru
* inode_sb_list_lock protects:
* sb->s_inodes, inode->i_sb_list
+ * inode_sb_list_lock protects:
+ * bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list
*
* Lock ordering:
* inode_lock
@@ -42,6 +45,9 @@
* inode_sb_list_lock
* inode->i_lock
* inode_lru_lock
+ *
+ * inode_wb_list_lock
+ * inode->i_lock
*/
/*
@@ -103,6 +109,7 @@ static struct hlist_head *inode_hashtable __read_mostly;
DEFINE_SPINLOCK(inode_lock);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock);
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_wb_list_lock);
/*
* iprune_sem provides exclusion between the kswapd or try_to_free_pages
@@ -462,10 +469,7 @@ static void evict(struct inode *inode)
BUG_ON(!(inode->i_state & I_FREEING));
- spin_lock(&inode_lock);
- list_del_init(&inode->i_wb_list);
- spin_unlock(&inode_lock);
-
+ inode_wb_list_del(inode);
inode_sb_list_del(inode);
if (op->evict_inode) {
diff --git a/fs/internal.h b/fs/internal.h
index 493baa1..fd3f700 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -106,7 +106,12 @@ extern void release_open_intent(struct nameidata *);
* inode.c
*/
extern int get_nr_dirty_inodes(void);
-extern int evict_inodes(struct super_block *);
+extern void evict_inodes(struct super_block *);
extern int invalidate_inodes(struct super_block *);
extern spinlock_t inode_sb_list_lock;
+
+/*
+ * fs-writeback.c
+ */
+extern void inode_wb_list_del(struct inode *inode);
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 242b6f8..e78a240 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -10,6 +10,7 @@
struct backing_dev_info;
extern spinlock_t inode_lock;
+extern spinlock_t inode_wb_list_lock;
/*
* fs/fs-writeback.c
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 15d5097..168ba5e 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -73,14 +73,14 @@ 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(&inode_wb_list_lock);
list_for_each_entry(inode, &wb->b_dirty, i_wb_list)
nr_dirty++;
list_for_each_entry(inode, &wb->b_io, i_wb_list)
nr_io++;
list_for_each_entry(inode, &wb->b_more_io, i_wb_list)
nr_more_io++;
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
global_dirty_limits(&background_thresh, &dirty_thresh);
bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh);
@@ -682,11 +682,11 @@ 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);
+ spin_lock(&inode_wb_list_lock);
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(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
}
bdi_unregister(bdi);
--
1.7.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH 2/3] fs: move i_wb_list out from under inode_lock
2010-10-28 11:42 ` [PATCH 2/3] fs: move i_wb_list " Dave Chinner
@ 2010-10-28 14:19 ` Christoph Hellwig
2010-10-28 21:47 ` Dave Chinner
0 siblings, 1 reply; 9+ messages in thread
From: Christoph Hellwig @ 2010-10-28 14:19 UTC (permalink / raw)
To: Dave Chinner; +Cc: viro, linux-fsdevel, linux-kernel
> + * Write out an inode's dirty pages. Called under inode_wb_list_lock. Either
> + * the caller has ref on the inode (either via __iget or via syscall against an
> + * fd) or the inode has I_WILL_FREE set.
Just drop mentioning of how we got the reference ,it's rather pointless.
> writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
> @@ -354,7 +368,7 @@ 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);
> + spin_unlock(&inode_wb_list_lock);
We don't actually need inode_wb_list_lock here. But I guess we can
fix this later and be conservative for now.
> @@ -963,63 +976,62 @@ void __mark_inode_dirty(struct inode *inode, int flags)
I think the __mark_inode_dirty cleanup should be a separate patch,
it's rather confusing in the current form.
> + if (was_dirty) {
> +out_unlock_inode:
> spin_unlock(&inode->i_lock);
> + return;
> + }
Please just move the label to the end of the function and add another
goto here.
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH 2/3] fs: move i_wb_list out from under inode_lock
2010-10-28 14:19 ` Christoph Hellwig
@ 2010-10-28 21:47 ` Dave Chinner
0 siblings, 0 replies; 9+ messages in thread
From: Dave Chinner @ 2010-10-28 21:47 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: viro, linux-fsdevel, linux-kernel
On Thu, Oct 28, 2010 at 10:19:49AM -0400, Christoph Hellwig wrote:
> > + * Write out an inode's dirty pages. Called under inode_wb_list_lock. Either
> > + * the caller has ref on the inode (either via __iget or via syscall against an
> > + * fd) or the inode has I_WILL_FREE set.
>
> Just drop mentioning of how we got the reference ,it's rather pointless.
OK.
> > writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
> > @@ -354,7 +368,7 @@ 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);
> > + spin_unlock(&inode_wb_list_lock);
>
> We don't actually need inode_wb_list_lock here. But I guess we can
> fix this later and be conservative for now.
Hmmm - I think you are right. However, there are lots of
opportunities for cleaning up the locking in this areaş so leaving
it for later is probably best.
> > @@ -963,63 +976,62 @@ void __mark_inode_dirty(struct inode *inode, int flags)
>
> I think the __mark_inode_dirty cleanup should be a separate patch,
> it's rather confusing in the current form.
Ok. I'll leave it out for now - there's various other cleanups
needed here now as well (e.g. the unlocked flags check is not needed
to avoid a global lock anymore) so I'll leave that for later, too.
> > + if (was_dirty) {
> > +out_unlock_inode:
> > spin_unlock(&inode->i_lock);
> > + return;
> > + }
>
> Please just move the label to the end of the function and add another
> goto here.
Will do.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH 3/3] fs: move i_hash out from under inode_lock
2010-10-28 11:42 [PATCH 0/3] fs: peel back the inode_lock some more Dave Chinner
2010-10-28 11:42 ` [PATCH 1/3] fs: move i_sb_list out from under inode_lock Dave Chinner
2010-10-28 11:42 ` [PATCH 2/3] fs: move i_wb_list " Dave Chinner
@ 2010-10-28 11:42 ` Dave Chinner
2010-10-28 14:24 ` Christoph Hellwig
2010-10-28 12:00 ` [PATCH 0/3] fs: peel back the inode_lock some more Christoph Hellwig
3 siblings, 1 reply; 9+ messages in thread
From: Dave Chinner @ 2010-10-28 11:42 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel
From: Dave Chinner <dchinner@redhat.com>
Protect the inode hash lists with a new global lock
inode_hash_lock and use it to protect the list manipulations and
traversals. This lock replaces the inode_lock as the inodes on the
list can be validity checked while holding the inode->i_lock and
hence the inode_lock is no longer needed to protect the lists.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/inode.c | 69 ++++++++++++++++++++++++++++++++++-------------------------
1 files changed, 40 insertions(+), 29 deletions(-)
diff --git a/fs/inode.c b/fs/inode.c
index 130aa74..738ba4e 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -37,6 +37,8 @@
* sb->s_inodes, inode->i_sb_list
* inode_sb_list_lock protects:
* bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list
+ * inode_hash_lock protects:
+ * inode_hashtable, inode->i_hash
*
* Lock ordering:
* inode_lock
@@ -48,6 +50,12 @@
*
* inode_wb_list_lock
* inode->i_lock
+ *
+ * inode_hash_lock
+ * inode->i_lock
+ *
+ * iunique_lock
+ * inode_hash_lock
*/
/*
@@ -83,6 +91,8 @@
static unsigned int i_hash_mask __read_mostly;
static unsigned int i_hash_shift __read_mostly;
+static struct hlist_head *inode_hashtable __read_mostly;
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock);
/*
* Each inode can be on two separate lists. One is
@@ -98,7 +108,6 @@ 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;
/*
* A simple spinlock to protect the list manipulations.
@@ -420,9 +429,9 @@ void __insert_inode_hash(struct inode *inode, unsigned long hashval)
{
struct hlist_head *b = inode_hashtable + hash(inode->i_sb, hashval);
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
hlist_add_head(&inode->i_hash, b);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
}
EXPORT_SYMBOL(__insert_inode_hash);
@@ -434,9 +443,9 @@ EXPORT_SYMBOL(__insert_inode_hash);
*/
void remove_inode_hash(struct inode *inode)
{
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
hlist_del_init(&inode->i_hash);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
}
EXPORT_SYMBOL(remove_inode_hash);
@@ -914,7 +923,7 @@ static struct inode *get_new_inode(struct super_block *sb,
if (inode) {
struct inode *old;
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
/* We released the lock, so.. */
old = find_inode(sb, head, test, data);
if (!old) {
@@ -925,8 +934,8 @@ static struct inode *get_new_inode(struct super_block *sb,
inode->i_state = I_NEW;
spin_unlock(&inode->i_lock);
hlist_add_head(&inode->i_hash, head);
+ spin_unlock(&inode_hash_lock);
inode_sb_list_add(inode);
- spin_unlock(&inode_lock);
/* Return the locked inode with I_NEW set, the
* caller is responsible for filling in the contents
@@ -939,7 +948,7 @@ static struct inode *get_new_inode(struct super_block *sb,
* us. Use the old inode instead of the one we just
* allocated.
*/
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
destroy_inode(inode);
inode = old;
wait_on_inode(inode);
@@ -947,7 +956,7 @@ static struct inode *get_new_inode(struct super_block *sb,
return inode;
set_failed:
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
destroy_inode(inode);
return NULL;
}
@@ -965,7 +974,7 @@ static struct inode *get_new_inode_fast(struct super_block *sb,
if (inode) {
struct inode *old;
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
/* We released the lock, so.. */
old = find_inode_fast(sb, head, ino);
if (!old) {
@@ -974,8 +983,8 @@ static struct inode *get_new_inode_fast(struct super_block *sb,
inode->i_state = I_NEW;
spin_unlock(&inode->i_lock);
hlist_add_head(&inode->i_hash, head);
+ spin_unlock(&inode_hash_lock);
inode_sb_list_add(inode);
- spin_unlock(&inode_lock);
/* Return the locked inode with I_NEW set, the
* caller is responsible for filling in the contents
@@ -988,7 +997,7 @@ static struct inode *get_new_inode_fast(struct super_block *sb,
* us. Use the old inode instead of the one we just
* allocated.
*/
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
destroy_inode(inode);
inode = old;
wait_on_inode(inode);
@@ -1009,10 +1018,14 @@ static int test_inode_iunique(struct super_block *sb, unsigned long ino)
struct hlist_node *node;
struct inode *inode;
+ spin_lock(&inode_hash_lock);
hlist_for_each_entry(inode, node, b, i_hash) {
- if (inode->i_ino == ino && inode->i_sb == sb)
+ if (inode->i_ino == ino && inode->i_sb == sb) {
+ spin_unlock(&inode_hash_lock);
return 0;
+ }
}
+ spin_unlock(&inode_hash_lock);
return 1;
}
@@ -1042,7 +1055,6 @@ ino_t iunique(struct super_block *sb, ino_t max_reserved)
static unsigned int counter;
ino_t res;
- spin_lock(&inode_lock);
spin_lock(&iunique_lock);
do {
if (counter <= max_reserved)
@@ -1050,7 +1062,6 @@ ino_t iunique(struct super_block *sb, ino_t max_reserved)
res = counter++;
} while (!test_inode_iunique(sb, res));
spin_unlock(&iunique_lock);
- spin_unlock(&inode_lock);
return res;
}
@@ -1102,15 +1113,15 @@ static struct inode *ifind(struct super_block *sb,
{
struct inode *inode;
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
inode = find_inode(sb, head, test, data);
if (inode) {
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
if (likely(wait))
wait_on_inode(inode);
return inode;
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
return NULL;
}
@@ -1134,14 +1145,14 @@ static struct inode *ifind_fast(struct super_block *sb,
{
struct inode *inode;
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
inode = find_inode_fast(sb, head, ino);
if (inode) {
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
wait_on_inode(inode);
return inode;
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
return NULL;
}
@@ -1306,7 +1317,7 @@ int insert_inode_locked(struct inode *inode)
while (1) {
struct hlist_node *node;
struct inode *old = NULL;
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
hlist_for_each_entry(old, node, head, i_hash) {
if (old->i_ino != ino)
continue;
@@ -1321,12 +1332,12 @@ int insert_inode_locked(struct inode *inode)
}
if (likely(!node)) {
hlist_add_head(&inode->i_hash, head);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
return 0;
}
__iget(old);
spin_unlock(&old->i_lock);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
wait_on_inode(old);
if (unlikely(!inode_unhashed(old))) {
iput(old);
@@ -1351,7 +1362,7 @@ int insert_inode_locked4(struct inode *inode, unsigned long hashval,
struct hlist_node *node;
struct inode *old = NULL;
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
hlist_for_each_entry(old, node, head, i_hash) {
if (old->i_sb != sb)
continue;
@@ -1366,12 +1377,12 @@ int insert_inode_locked4(struct inode *inode, unsigned long hashval,
}
if (likely(!node)) {
hlist_add_head(&inode->i_hash, head);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
return 0;
}
__iget(old);
spin_unlock(&old->i_lock);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
wait_on_inode(old);
if (unlikely(!inode_unhashed(old))) {
iput(old);
@@ -1651,10 +1662,10 @@ 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);
+ spin_unlock(&inode_hash_lock);
schedule();
finish_wait(wq, &wait.wait);
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
}
static __initdata unsigned long ihash_entries;
--
1.7.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH 3/3] fs: move i_hash out from under inode_lock
2010-10-28 11:42 ` [PATCH 3/3] fs: move i_hash " Dave Chinner
@ 2010-10-28 14:24 ` Christoph Hellwig
0 siblings, 0 replies; 9+ messages in thread
From: Christoph Hellwig @ 2010-10-28 14:24 UTC (permalink / raw)
To: Dave Chinner; +Cc: viro, linux-fsdevel, linux-kernel
> @@ -925,8 +934,8 @@ static struct inode *get_new_inode(struct super_block *sb,
> inode->i_state = I_NEW;
> spin_unlock(&inode->i_lock);
> hlist_add_head(&inode->i_hash, head);
> + spin_unlock(&inode_hash_lock);
> inode_sb_list_add(inode);
> - spin_unlock(&inode_lock);
Al said he wanted to have the sb lock nest inside the hash lock for now
I think. Doubt it matters much, but it keeps the behaviour that we
can't look up an inode which is not added to the per-sb list yet.
After that a better patch description might be:
"rename inode_lock to inode_hash_lock"
as the inode_lock coverage after the previous patches should be 100%
identical to the new hash lock.
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 0/3] fs: peel back the inode_lock some more
2010-10-28 11:42 [PATCH 0/3] fs: peel back the inode_lock some more Dave Chinner
` (2 preceding siblings ...)
2010-10-28 11:42 ` [PATCH 3/3] fs: move i_hash " Dave Chinner
@ 2010-10-28 12:00 ` Christoph Hellwig
3 siblings, 0 replies; 9+ messages in thread
From: Christoph Hellwig @ 2010-10-28 12:00 UTC (permalink / raw)
To: Dave Chinner; +Cc: viro, linux-fsdevel, linux-kernel
Shouldn't inode_lock be completely gone after these?
also I hope moving to global locks really is just a step inbetween.
Especially for writeback I doubt moving from inode_lock to another
global lock makes a whole lot of difference - nevermind that it's
not too smart to lock per-object lists with a global lock.
^ permalink raw reply [flat|nested] 9+ messages in thread