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-rw-r--r--fs/fs-writeback.c108
1 files changed, 81 insertions, 27 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 4b37f7cea4d..ea8592b9069 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -42,9 +42,10 @@ struct wb_writeback_args {
long nr_pages;
struct super_block *sb;
enum writeback_sync_modes sync_mode;
- int for_kupdate:1;
- int range_cyclic:1;
- int for_background:1;
+ unsigned int for_kupdate:1;
+ unsigned int range_cyclic:1;
+ unsigned int for_background:1;
+ unsigned int sb_pinned:1;
};
/*
@@ -192,7 +193,8 @@ static void bdi_wait_on_work_clear(struct bdi_work *work)
}
static void bdi_alloc_queue_work(struct backing_dev_info *bdi,
- struct wb_writeback_args *args)
+ struct wb_writeback_args *args,
+ int wait)
{
struct bdi_work *work;
@@ -204,6 +206,8 @@ static void bdi_alloc_queue_work(struct backing_dev_info *bdi,
if (work) {
bdi_work_init(work, args);
bdi_queue_work(bdi, work);
+ if (wait)
+ bdi_wait_on_work_clear(work);
} else {
struct bdi_writeback *wb = &bdi->wb;
@@ -230,6 +234,11 @@ static void bdi_sync_writeback(struct backing_dev_info *bdi,
.sync_mode = WB_SYNC_ALL,
.nr_pages = LONG_MAX,
.range_cyclic = 0,
+ /*
+ * Setting sb_pinned is not necessary for WB_SYNC_ALL, but
+ * lets make it explicitly clear.
+ */
+ .sb_pinned = 1,
};
struct bdi_work work;
@@ -245,21 +254,23 @@ static void bdi_sync_writeback(struct backing_dev_info *bdi,
* @bdi: the backing device to write from
* @sb: write inodes from this super_block
* @nr_pages: the number of pages to write
+ * @sb_locked: caller already holds sb umount sem.
*
* Description:
* This does WB_SYNC_NONE opportunistic writeback. The IO is only
* started when this function returns, we make no guarentees on
- * completion. Caller need not hold sb s_umount semaphore.
+ * completion. Caller specifies whether sb umount sem is held already or not.
*
*/
void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb,
- long nr_pages)
+ long nr_pages, int sb_locked)
{
struct wb_writeback_args args = {
.sb = sb,
.sync_mode = WB_SYNC_NONE,
.nr_pages = nr_pages,
.range_cyclic = 1,
+ .sb_pinned = sb_locked,
};
/*
@@ -271,7 +282,7 @@ void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb,
args.for_background = 1;
}
- bdi_alloc_queue_work(bdi, &args);
+ bdi_alloc_queue_work(bdi, &args, sb_locked);
}
/*
@@ -398,11 +409,11 @@ static void inode_wait_for_writeback(struct inode *inode)
wait_queue_head_t *wqh;
wqh = bit_waitqueue(&inode->i_state, __I_SYNC);
- do {
+ while (inode->i_state & I_SYNC) {
spin_unlock(&inode_lock);
__wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE);
spin_lock(&inode_lock);
- } while (inode->i_state & I_SYNC);
+ }
}
/*
@@ -452,11 +463,9 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
BUG_ON(inode->i_state & I_SYNC);
- /* Set I_SYNC, reset I_DIRTY */
- dirty = inode->i_state & I_DIRTY;
+ /* Set I_SYNC, reset I_DIRTY_PAGES */
inode->i_state |= I_SYNC;
- inode->i_state &= ~I_DIRTY;
-
+ inode->i_state &= ~I_DIRTY_PAGES;
spin_unlock(&inode_lock);
ret = do_writepages(mapping, wbc);
@@ -472,6 +481,15 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
ret = err;
}
+ /*
+ * Some filesystems may redirty the inode during the writeback
+ * due to delalloc, clear dirty metadata flags right before
+ * write_inode()
+ */
+ spin_lock(&inode_lock);
+ dirty = inode->i_state & I_DIRTY;
+ inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC);
+ 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);
@@ -577,7 +595,7 @@ static enum sb_pin_state pin_sb_for_writeback(struct writeback_control *wbc,
/*
* Caller must already hold the ref for this
*/
- if (wbc->sync_mode == WB_SYNC_ALL) {
+ if (wbc->sync_mode == WB_SYNC_ALL || wbc->sb_pinned) {
WARN_ON(!rwsem_is_locked(&sb->s_umount));
return SB_NOT_PINNED;
}
@@ -751,6 +769,7 @@ static long wb_writeback(struct bdi_writeback *wb,
.for_kupdate = args->for_kupdate,
.for_background = args->for_background,
.range_cyclic = args->range_cyclic,
+ .sb_pinned = args->sb_pinned,
};
unsigned long oldest_jif;
long wrote = 0;
@@ -852,6 +871,12 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb)
unsigned long expired;
long nr_pages;
+ /*
+ * When set to zero, disable periodic writeback
+ */
+ if (!dirty_writeback_interval)
+ return 0;
+
expired = wb->last_old_flush +
msecs_to_jiffies(dirty_writeback_interval * 10);
if (time_before(jiffies, expired))
@@ -887,6 +912,7 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
while ((work = get_next_work_item(bdi, wb)) != NULL) {
struct wb_writeback_args args = work->args;
+ int post_clear;
/*
* Override sync mode, in case we must wait for completion
@@ -894,11 +920,13 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
if (force_wait)
work->args.sync_mode = args.sync_mode = WB_SYNC_ALL;
+ post_clear = WB_SYNC_ALL || args.sb_pinned;
+
/*
* If this isn't a data integrity operation, just notify
* that we have seen this work and we are now starting it.
*/
- if (args.sync_mode == WB_SYNC_NONE)
+ if (!post_clear)
wb_clear_pending(wb, work);
wrote += wb_writeback(wb, &args);
@@ -907,7 +935,7 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
* This is a data integrity writeback, so only do the
* notification when we have completed the work.
*/
- if (args.sync_mode == WB_SYNC_ALL)
+ if (post_clear)
wb_clear_pending(wb, work);
}
@@ -947,8 +975,17 @@ int bdi_writeback_task(struct bdi_writeback *wb)
break;
}
- wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
- schedule_timeout_interruptible(wait_jiffies);
+ if (dirty_writeback_interval) {
+ wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
+ schedule_timeout_interruptible(wait_jiffies);
+ } else {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (list_empty_careful(&wb->bdi->work_list) &&
+ !kthread_should_stop())
+ schedule();
+ __set_current_state(TASK_RUNNING);
+ }
+
try_to_freeze();
}
@@ -974,7 +1011,7 @@ static void bdi_writeback_all(struct super_block *sb, long nr_pages)
if (!bdi_has_dirty_io(bdi))
continue;
- bdi_alloc_queue_work(bdi, &args);
+ bdi_alloc_queue_work(bdi, &args, 0);
}
rcu_read_unlock();
@@ -1183,6 +1220,18 @@ static void wait_sb_inodes(struct super_block *sb)
iput(old_inode);
}
+static void __writeback_inodes_sb(struct super_block *sb, int sb_locked)
+{
+ unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
+ unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
+ long nr_to_write;
+
+ nr_to_write = nr_dirty + nr_unstable +
+ (inodes_stat.nr_inodes - inodes_stat.nr_unused);
+
+ bdi_start_writeback(sb->s_bdi, sb, nr_to_write, sb_locked);
+}
+
/**
* writeback_inodes_sb - writeback dirty inodes from given super_block
* @sb: the superblock
@@ -1194,18 +1243,23 @@ static void wait_sb_inodes(struct super_block *sb)
*/
void writeback_inodes_sb(struct super_block *sb)
{
- unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
- unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
- long nr_to_write;
-
- nr_to_write = nr_dirty + nr_unstable +
- (inodes_stat.nr_inodes - inodes_stat.nr_unused);
-
- bdi_start_writeback(sb->s_bdi, sb, nr_to_write);
+ __writeback_inodes_sb(sb, 0);
}
EXPORT_SYMBOL(writeback_inodes_sb);
/**
+ * writeback_inodes_sb_locked - writeback dirty inodes from given super_block
+ * @sb: the superblock
+ *
+ * Like writeback_inodes_sb(), except the caller already holds the
+ * sb umount sem.
+ */
+void writeback_inodes_sb_locked(struct super_block *sb)
+{
+ __writeback_inodes_sb(sb, 1);
+}
+
+/**
* writeback_inodes_sb_if_idle - start writeback if none underway
* @sb: the superblock
*