writeback: get rid of generic_sync_sb_inodes() export
This adds two new exported functions:
- writeback_inodes_sb(), which only attempts to writeback dirty inodes on
this super_block, for WB_SYNC_NONE writeout.
- sync_inodes_sb(), which writes out all dirty inodes on this super_block
and also waits for the IO to complete.
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index c54226b..271e5f4 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -458,8 +458,8 @@
* on the writer throttling path, and we get decent balancing between many
* throttled threads: we don't want them all piling up on inode_sync_wait.
*/
-void generic_sync_sb_inodes(struct super_block *sb,
- struct writeback_control *wbc)
+static void generic_sync_sb_inodes(struct super_block *sb,
+ struct writeback_control *wbc)
{
const unsigned long start = jiffies; /* livelock avoidance */
int sync = wbc->sync_mode == WB_SYNC_ALL;
@@ -593,13 +593,6 @@
return; /* Leave any unwritten inodes on s_io */
}
-EXPORT_SYMBOL_GPL(generic_sync_sb_inodes);
-
-static void sync_sb_inodes(struct super_block *sb,
- struct writeback_control *wbc)
-{
- generic_sync_sb_inodes(sb, wbc);
-}
/*
* Start writeback of dirty pagecache data against all unlocked inodes.
@@ -640,7 +633,7 @@
*/
if (down_read_trylock(&sb->s_umount)) {
if (sb->s_root)
- sync_sb_inodes(sb, wbc);
+ generic_sync_sb_inodes(sb, wbc);
up_read(&sb->s_umount);
}
spin_lock(&sb_lock);
@@ -653,35 +646,56 @@
spin_unlock(&sb_lock);
}
-/*
- * writeback and wait upon the filesystem's dirty inodes. The caller will
- * do this in two passes - one to write, and one to wait.
+/**
+ * writeback_inodes_sb - writeback dirty inodes from given super_block
+ * @sb: the superblock
*
- * A finite limit is set on the number of pages which will be written.
- * To prevent infinite livelock of sys_sync().
- *
- * We add in the number of potentially dirty inodes, because each inode write
- * can dirty pagecache in the underlying blockdev.
+ * Start writeback on some inodes on this super_block. No guarantees are made
+ * on how many (if any) will be written, and this function does not wait
+ * for IO completion of submitted IO. The number of pages submitted is
+ * returned.
*/
-void sync_inodes_sb(struct super_block *sb, int wait)
+long writeback_inodes_sb(struct super_block *sb)
{
struct writeback_control wbc = {
- .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_NONE,
+ .sync_mode = WB_SYNC_NONE,
.range_start = 0,
.range_end = LLONG_MAX,
};
+ unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
+ unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
+ long nr_to_write;
- if (!wait) {
- unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
- unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
-
- wbc.nr_to_write = nr_dirty + nr_unstable +
+ nr_to_write = nr_dirty + nr_unstable +
(inodes_stat.nr_inodes - inodes_stat.nr_unused);
- } else
- wbc.nr_to_write = LONG_MAX; /* doesn't actually matter */
- sync_sb_inodes(sb, &wbc);
+ wbc.nr_to_write = nr_to_write;
+ generic_sync_sb_inodes(sb, &wbc);
+ return nr_to_write - wbc.nr_to_write;
}
+EXPORT_SYMBOL(writeback_inodes_sb);
+
+/**
+ * sync_inodes_sb - sync sb inode pages
+ * @sb: the superblock
+ *
+ * This function writes and waits on any dirty inode belonging to this
+ * super_block. The number of pages synced is returned.
+ */
+long sync_inodes_sb(struct super_block *sb)
+{
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL,
+ .range_start = 0,
+ .range_end = LLONG_MAX,
+ };
+ long nr_to_write = LONG_MAX; /* doesn't actually matter */
+
+ wbc.nr_to_write = nr_to_write;
+ generic_sync_sb_inodes(sb, &wbc);
+ return nr_to_write - wbc.nr_to_write;
+}
+EXPORT_SYMBOL(sync_inodes_sb);
/**
* write_inode_now - write an inode to disk
diff --git a/fs/sync.c b/fs/sync.c
index 3422ba6..66f2104 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -19,20 +19,22 @@
SYNC_FILE_RANGE_WAIT_AFTER)
/*
- * Do the filesystem syncing work. For simple filesystems sync_inodes_sb(sb, 0)
- * just dirties buffers with inodes so we have to submit IO for these buffers
- * via __sync_blockdev(). This also speeds up the wait == 1 case since in that
- * case write_inode() functions do sync_dirty_buffer() and thus effectively
- * write one block at a time.
+ * Do the filesystem syncing work. For simple filesystems
+ * writeback_inodes_sb(sb) just dirties buffers with inodes so we have to
+ * submit IO for these buffers via __sync_blockdev(). This also speeds up the
+ * wait == 1 case since in that case write_inode() functions do
+ * sync_dirty_buffer() and thus effectively write one block at a time.
*/
static int __sync_filesystem(struct super_block *sb, int wait)
{
/* Avoid doing twice syncing and cache pruning for quota sync */
- if (!wait)
+ if (!wait) {
writeout_quota_sb(sb, -1);
- else
+ writeback_inodes_sb(sb);
+ } else {
sync_quota_sb(sb, -1);
- sync_inodes_sb(sb, wait);
+ sync_inodes_sb(sb);
+ }
if (sb->s_op->sync_fs)
sb->s_op->sync_fs(sb, wait);
return __sync_blockdev(sb->s_bdev, wait);
diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index eaf6d89..1c8991b 100644
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -65,26 +65,14 @@
static int shrink_liability(struct ubifs_info *c, int nr_to_write)
{
int nr_written;
- struct writeback_control wbc = {
- .sync_mode = WB_SYNC_NONE,
- .range_end = LLONG_MAX,
- .nr_to_write = nr_to_write,
- };
- generic_sync_sb_inodes(c->vfs_sb, &wbc);
- nr_written = nr_to_write - wbc.nr_to_write;
-
+ nr_written = writeback_inodes_sb(c->vfs_sb);
if (!nr_written) {
/*
* Re-try again but wait on pages/inodes which are being
* written-back concurrently (e.g., by pdflush).
*/
- memset(&wbc, 0, sizeof(struct writeback_control));
- wbc.sync_mode = WB_SYNC_ALL;
- wbc.range_end = LLONG_MAX;
- wbc.nr_to_write = nr_to_write;
- generic_sync_sb_inodes(c->vfs_sb, &wbc);
- nr_written = nr_to_write - wbc.nr_to_write;
+ nr_written = sync_inodes_sb(c->vfs_sb);
}
dbg_budg("%d pages were written back", nr_written);
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 26d2e0d..8d6050a 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -438,12 +438,6 @@
{
int i, err;
struct ubifs_info *c = sb->s_fs_info;
- struct writeback_control wbc = {
- .sync_mode = WB_SYNC_ALL,
- .range_start = 0,
- .range_end = LLONG_MAX,
- .nr_to_write = LONG_MAX,
- };
/*
* Zero @wait is just an advisory thing to help the file system shove
@@ -462,7 +456,7 @@
* the user be able to get more accurate results of 'statfs()' after
* they synchronize the file system.
*/
- generic_sync_sb_inodes(sb, &wbc);
+ sync_inodes_sb(sb);
/*
* Synchronize write buffers, because 'ubifs_run_commit()' does not