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authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-05 20:34:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-05 20:34:28 -0700
commit7d9071a095023cd1db8fa18fa0d648dc1a5210e0 (patch)
tree072b462e43912b9dfc321136f3367114dcb8f2b3 /fs/fs-writeback.c
parentbd779669945ed9982890da789ad32e3bd0d41f14 (diff)
parent397d425dc26da728396e66d392d5dcb8dac30c37 (diff)
downloadop-kernel-dev-7d9071a095023cd1db8fa18fa0d648dc1a5210e0.zip
op-kernel-dev-7d9071a095023cd1db8fa18fa0d648dc1a5210e0.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro: "In this one: - d_move fixes (Eric Biederman) - UFS fixes (me; locking is mostly sane now, a bunch of bugs in error handling ought to be fixed) - switch of sb_writers to percpu rwsem (Oleg Nesterov) - superblock scalability (Josef Bacik and Dave Chinner) - swapon(2) race fix (Hugh Dickins)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (65 commits) vfs: Test for and handle paths that are unreachable from their mnt_root dcache: Reduce the scope of i_lock in d_splice_alias dcache: Handle escaped paths in prepend_path mm: fix potential data race in SyS_swapon inode: don't softlockup when evicting inodes inode: rename i_wb_list to i_io_list sync: serialise per-superblock sync operations inode: convert inode_sb_list_lock to per-sb inode: add hlist_fake to avoid the inode hash lock in evict writeback: plug writeback at a high level change sb_writers to use percpu_rw_semaphore shift percpu_counter_destroy() into destroy_super_work() percpu-rwsem: kill CONFIG_PERCPU_RWSEM percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire() percpu-rwsem: introduce percpu_down_read_trylock() document rwsem_release() in sb_wait_write() fix the broken lockdep logic in __sb_start_write() introduce __sb_writers_{acquired,release}() helpers ufs_inode_get{frag,block}(): get rid of 'phys' argument ufs_getfrag_block(): tidy up a bit ...
Diffstat (limited to 'fs/fs-writeback.c')
-rw-r--r--fs/fs-writeback.c72
1 files changed, 43 insertions, 29 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 5fa588e..ae0f438 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -88,7 +88,7 @@ unsigned int dirtytime_expire_interval = 12 * 60 * 60;
static inline struct inode *wb_inode(struct list_head *head)
{
- return list_entry(head, struct inode, i_wb_list);
+ return list_entry(head, struct inode, i_io_list);
}
/*
@@ -125,22 +125,22 @@ static void wb_io_lists_depopulated(struct bdi_writeback *wb)
}
/**
- * inode_wb_list_move_locked - move an inode onto a bdi_writeback IO list
+ * inode_io_list_move_locked - move an inode onto a bdi_writeback IO list
* @inode: inode to be moved
* @wb: target bdi_writeback
* @head: one of @wb->b_{dirty|io|more_io}
*
- * Move @inode->i_wb_list to @list of @wb and set %WB_has_dirty_io.
+ * Move @inode->i_io_list to @list of @wb and set %WB_has_dirty_io.
* Returns %true if @inode is the first occupant of the !dirty_time IO
* lists; otherwise, %false.
*/
-static bool inode_wb_list_move_locked(struct inode *inode,
+static bool inode_io_list_move_locked(struct inode *inode,
struct bdi_writeback *wb,
struct list_head *head)
{
assert_spin_locked(&wb->list_lock);
- list_move(&inode->i_wb_list, head);
+ list_move(&inode->i_io_list, head);
/* dirty_time doesn't count as dirty_io until expiration */
if (head != &wb->b_dirty_time)
@@ -151,19 +151,19 @@ static bool inode_wb_list_move_locked(struct inode *inode,
}
/**
- * inode_wb_list_del_locked - remove an inode from its bdi_writeback IO list
+ * inode_io_list_del_locked - remove an inode from its bdi_writeback IO list
* @inode: inode to be removed
* @wb: bdi_writeback @inode is being removed from
*
* Remove @inode which may be on one of @wb->b_{dirty|io|more_io} lists and
* clear %WB_has_dirty_io if all are empty afterwards.
*/
-static void inode_wb_list_del_locked(struct inode *inode,
+static void inode_io_list_del_locked(struct inode *inode,
struct bdi_writeback *wb)
{
assert_spin_locked(&wb->list_lock);
- list_del_init(&inode->i_wb_list);
+ list_del_init(&inode->i_io_list);
wb_io_lists_depopulated(wb);
}
@@ -351,7 +351,7 @@ static void inode_switch_wbs_work_fn(struct work_struct *work)
/*
* Once I_FREEING is visible under i_lock, the eviction path owns
- * the inode and we shouldn't modify ->i_wb_list.
+ * the inode and we shouldn't modify ->i_io_list.
*/
if (unlikely(inode->i_state & I_FREEING))
goto skip_switch;
@@ -390,16 +390,16 @@ static void inode_switch_wbs_work_fn(struct work_struct *work)
* is always correct including from ->b_dirty_time. The transfer
* preserves @inode->dirtied_when ordering.
*/
- if (!list_empty(&inode->i_wb_list)) {
+ if (!list_empty(&inode->i_io_list)) {
struct inode *pos;
- inode_wb_list_del_locked(inode, old_wb);
+ inode_io_list_del_locked(inode, old_wb);
inode->i_wb = new_wb;
- list_for_each_entry(pos, &new_wb->b_dirty, i_wb_list)
+ list_for_each_entry(pos, &new_wb->b_dirty, i_io_list)
if (time_after_eq(inode->dirtied_when,
pos->dirtied_when))
break;
- inode_wb_list_move_locked(inode, new_wb, pos->i_wb_list.prev);
+ inode_io_list_move_locked(inode, new_wb, pos->i_io_list.prev);
} else {
inode->i_wb = new_wb;
}
@@ -961,12 +961,12 @@ void wb_start_background_writeback(struct bdi_writeback *wb)
/*
* Remove the inode from the writeback list it is on.
*/
-void inode_wb_list_del(struct inode *inode)
+void inode_io_list_del(struct inode *inode)
{
struct bdi_writeback *wb;
wb = inode_to_wb_and_lock_list(inode);
- inode_wb_list_del_locked(inode, wb);
+ inode_io_list_del_locked(inode, wb);
spin_unlock(&wb->list_lock);
}
@@ -988,7 +988,7 @@ static void redirty_tail(struct inode *inode, struct bdi_writeback *wb)
if (time_before(inode->dirtied_when, tail->dirtied_when))
inode->dirtied_when = jiffies;
}
- inode_wb_list_move_locked(inode, wb, &wb->b_dirty);
+ inode_io_list_move_locked(inode, wb, &wb->b_dirty);
}
/*
@@ -996,7 +996,7 @@ static void redirty_tail(struct inode *inode, struct bdi_writeback *wb)
*/
static void requeue_io(struct inode *inode, struct bdi_writeback *wb)
{
- inode_wb_list_move_locked(inode, wb, &wb->b_more_io);
+ inode_io_list_move_locked(inode, wb, &wb->b_more_io);
}
static void inode_sync_complete(struct inode *inode)
@@ -1055,7 +1055,7 @@ static int move_expired_inodes(struct list_head *delaying_queue,
if (older_than_this &&
inode_dirtied_after(inode, *older_than_this))
break;
- list_move(&inode->i_wb_list, &tmp);
+ list_move(&inode->i_io_list, &tmp);
moved++;
if (flags & EXPIRE_DIRTY_ATIME)
set_bit(__I_DIRTY_TIME_EXPIRED, &inode->i_state);
@@ -1078,7 +1078,7 @@ static int move_expired_inodes(struct list_head *delaying_queue,
list_for_each_prev_safe(pos, node, &tmp) {
inode = wb_inode(pos);
if (inode->i_sb == sb)
- list_move(&inode->i_wb_list, dispatch_queue);
+ list_move(&inode->i_io_list, dispatch_queue);
}
}
out:
@@ -1232,10 +1232,10 @@ static void requeue_inode(struct inode *inode, struct bdi_writeback *wb,
redirty_tail(inode, wb);
} else if (inode->i_state & I_DIRTY_TIME) {
inode->dirtied_when = jiffies;
- inode_wb_list_move_locked(inode, wb, &wb->b_dirty_time);
+ inode_io_list_move_locked(inode, wb, &wb->b_dirty_time);
} else {
/* The inode is clean. Remove from writeback lists. */
- inode_wb_list_del_locked(inode, wb);
+ inode_io_list_del_locked(inode, wb);
}
}
@@ -1378,7 +1378,7 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb,
* touch it. See comment above for explanation.
*/
if (!(inode->i_state & I_DIRTY_ALL))
- inode_wb_list_del_locked(inode, wb);
+ inode_io_list_del_locked(inode, wb);
spin_unlock(&wb->list_lock);
inode_sync_complete(inode);
out:
@@ -1439,7 +1439,9 @@ static long writeback_sb_inodes(struct super_block *sb,
unsigned long start_time = jiffies;
long write_chunk;
long wrote = 0; /* count both pages and inodes */
+ struct blk_plug plug;
+ blk_start_plug(&plug);
while (!list_empty(&wb->b_io)) {
struct inode *inode = wb_inode(wb->b_io.prev);
@@ -1537,6 +1539,7 @@ static long writeback_sb_inodes(struct super_block *sb,
break;
}
}
+ blk_finish_plug(&plug);
return wrote;
}
@@ -2088,7 +2091,7 @@ void __mark_inode_dirty(struct inode *inode, int flags)
else
dirty_list = &wb->b_dirty_time;
- wakeup_bdi = inode_wb_list_move_locked(inode, wb,
+ wakeup_bdi = inode_io_list_move_locked(inode, wb,
dirty_list);
spin_unlock(&wb->list_lock);
@@ -2111,6 +2114,15 @@ out_unlock_inode:
}
EXPORT_SYMBOL(__mark_inode_dirty);
+/*
+ * The @s_sync_lock is used to serialise concurrent sync operations
+ * to avoid lock contention problems with concurrent wait_sb_inodes() calls.
+ * Concurrent callers will block on the s_sync_lock rather than doing contending
+ * walks. The queueing maintains sync(2) required behaviour as all the IO that
+ * has been issued up to the time this function is enter is guaranteed to be
+ * completed by the time we have gained the lock and waited for all IO that is
+ * in progress regardless of the order callers are granted the lock.
+ */
static void wait_sb_inodes(struct super_block *sb)
{
struct inode *inode, *old_inode = NULL;
@@ -2121,7 +2133,8 @@ static void wait_sb_inodes(struct super_block *sb)
*/
WARN_ON(!rwsem_is_locked(&sb->s_umount));
- spin_lock(&inode_sb_list_lock);
+ mutex_lock(&sb->s_sync_lock);
+ spin_lock(&sb->s_inode_list_lock);
/*
* Data integrity sync. Must wait for all pages under writeback,
@@ -2141,14 +2154,14 @@ static void wait_sb_inodes(struct super_block *sb)
}
__iget(inode);
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_sb_list_lock);
+ spin_unlock(&sb->s_inode_list_lock);
/*
* 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
+ * s_inode_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
+ * s_inode_list_lock. So we keep the reference and iput it
* later.
*/
iput(old_inode);
@@ -2158,10 +2171,11 @@ static void wait_sb_inodes(struct super_block *sb)
cond_resched();
- spin_lock(&inode_sb_list_lock);
+ spin_lock(&sb->s_inode_list_lock);
}
- spin_unlock(&inode_sb_list_lock);
+ spin_unlock(&sb->s_inode_list_lock);
iput(old_inode);
+ mutex_unlock(&sb->s_sync_lock);
}
static void __writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr,
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