Merge tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux
Pull writeback fixes from Wu Fengguang:
"Two writeback fixes
- fix negative (setpoint - dirty) in 32bit archs
- use down_read_trylock() in writeback_inodes_sb(_nr)_if_idle()"
* tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
Negative (setpoint-dirty) in bdi_position_ratio()
vfs: re-implement writeback_inodes_sb(_nr)_if_idle() and rename them
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1e59ed5..cf54bdf 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3689,20 +3689,6 @@
return 0;
}
-static int writeback_inodes_sb_nr_if_idle_safe(struct super_block *sb,
- unsigned long nr_pages,
- enum wb_reason reason)
-{
- if (!writeback_in_progress(sb->s_bdi) &&
- down_read_trylock(&sb->s_umount)) {
- writeback_inodes_sb_nr(sb, nr_pages, reason);
- up_read(&sb->s_umount);
- return 1;
- }
-
- return 0;
-}
-
/*
* shrink metadata reservation for delalloc
*/
@@ -3735,9 +3721,9 @@
while (delalloc_bytes && loops < 3) {
max_reclaim = min(delalloc_bytes, to_reclaim);
nr_pages = max_reclaim >> PAGE_CACHE_SHIFT;
- writeback_inodes_sb_nr_if_idle_safe(root->fs_info->sb,
- nr_pages,
- WB_REASON_FS_FREE_SPACE);
+ try_to_writeback_inodes_sb_nr(root->fs_info->sb,
+ nr_pages,
+ WB_REASON_FS_FREE_SPACE);
/*
* We need to wait for the async pages to actually start before
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9c4f4b1..9ea0cde 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2512,12 +2512,8 @@
/*
* Start pushing delalloc when 1/2 of free blocks are dirty.
*/
- if (dirty_blocks && (free_blocks < 2 * dirty_blocks) &&
- !writeback_in_progress(sb->s_bdi) &&
- down_read_trylock(&sb->s_umount)) {
- writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
- up_read(&sb->s_umount);
- }
+ if (dirty_blocks && (free_blocks < 2 * dirty_blocks))
+ try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
if (2 * free_blocks < 3 * dirty_blocks ||
free_blocks < (dirty_blocks + EXT4_FREECLUSTERS_WATERMARK)) {
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 359494e..21f46fb 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1344,47 +1344,43 @@
EXPORT_SYMBOL(writeback_inodes_sb);
/**
- * writeback_inodes_sb_if_idle - start writeback if none underway
- * @sb: the superblock
- * @reason: reason why some writeback work was initiated
- *
- * Invoke writeback_inodes_sb if no writeback is currently underway.
- * Returns 1 if writeback was started, 0 if not.
- */
-int writeback_inodes_sb_if_idle(struct super_block *sb, enum wb_reason reason)
-{
- if (!writeback_in_progress(sb->s_bdi)) {
- down_read(&sb->s_umount);
- writeback_inodes_sb(sb, reason);
- up_read(&sb->s_umount);
- return 1;
- } else
- return 0;
-}
-EXPORT_SYMBOL(writeback_inodes_sb_if_idle);
-
-/**
- * writeback_inodes_sb_nr_if_idle - start writeback if none underway
+ * try_to_writeback_inodes_sb_nr - try to start writeback if none underway
* @sb: the superblock
* @nr: the number of pages to write
- * @reason: reason why some writeback work was initiated
+ * @reason: the reason of writeback
*
- * Invoke writeback_inodes_sb if no writeback is currently underway.
+ * Invoke writeback_inodes_sb_nr if no writeback is currently underway.
* Returns 1 if writeback was started, 0 if not.
*/
-int writeback_inodes_sb_nr_if_idle(struct super_block *sb,
- unsigned long nr,
- enum wb_reason reason)
+int try_to_writeback_inodes_sb_nr(struct super_block *sb,
+ unsigned long nr,
+ enum wb_reason reason)
{
- if (!writeback_in_progress(sb->s_bdi)) {
- down_read(&sb->s_umount);
- writeback_inodes_sb_nr(sb, nr, reason);
- up_read(&sb->s_umount);
+ if (writeback_in_progress(sb->s_bdi))
return 1;
- } else
+
+ if (!down_read_trylock(&sb->s_umount))
return 0;
+
+ writeback_inodes_sb_nr(sb, nr, reason);
+ up_read(&sb->s_umount);
+ return 1;
}
-EXPORT_SYMBOL(writeback_inodes_sb_nr_if_idle);
+EXPORT_SYMBOL(try_to_writeback_inodes_sb_nr);
+
+/**
+ * try_to_writeback_inodes_sb - try to start writeback if none underway
+ * @sb: the superblock
+ * @reason: reason why some writeback work was initiated
+ *
+ * Implement by try_to_writeback_inodes_sb_nr()
+ * Returns 1 if writeback was started, 0 if not.
+ */
+int try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason)
+{
+ return try_to_writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason);
+}
+EXPORT_SYMBOL(try_to_writeback_inodes_sb);
/**
* sync_inodes_sb - sync sb inode pages
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index b82a83a..9a9367c 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -87,9 +87,9 @@
void writeback_inodes_sb(struct super_block *, enum wb_reason reason);
void writeback_inodes_sb_nr(struct super_block *, unsigned long nr,
enum wb_reason reason);
-int writeback_inodes_sb_if_idle(struct super_block *, enum wb_reason reason);
-int writeback_inodes_sb_nr_if_idle(struct super_block *, unsigned long nr,
- enum wb_reason reason);
+int try_to_writeback_inodes_sb(struct super_block *, enum wb_reason reason);
+int try_to_writeback_inodes_sb_nr(struct super_block *, unsigned long nr,
+ enum wb_reason reason);
void sync_inodes_sb(struct super_block *);
long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages,
enum wb_reason reason);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 742c405..efe6814 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -696,7 +696,7 @@
* => fast response on large errors; small oscillation near setpoint
*/
setpoint = (freerun + limit) / 2;
- x = div_s64((setpoint - dirty) << RATELIMIT_CALC_SHIFT,
+ x = div_s64(((s64)setpoint - (s64)dirty) << RATELIMIT_CALC_SHIFT,
limit - setpoint + 1);
pos_ratio = x;
pos_ratio = pos_ratio * x >> RATELIMIT_CALC_SHIFT;