/**
* bdi_start_writeback - start writeback
* @bdi: the backing device to write from
+ * @sb: write inodes from this super_block
* @nr_pages: the number of pages to write
*
* Description:
* completion. Caller need not hold sb s_umount semaphore.
*
*/
-void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages)
+void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb,
+ long nr_pages)
{
struct wb_writeback_args args = {
+ .sb = sb,
.sync_mode = WB_SYNC_NONE,
.nr_pages = nr_pages,
.range_cyclic = 1,
struct list_head *dispatch_queue,
unsigned long *older_than_this)
{
+ LIST_HEAD(tmp);
+ struct list_head *pos, *node;
+ struct super_block *sb = NULL;
+ struct inode *inode;
+ int do_sb_sort = 0;
+
while (!list_empty(delaying_queue)) {
- struct inode *inode = list_entry(delaying_queue->prev,
- struct inode, i_list);
+ inode = list_entry(delaying_queue->prev, struct inode, i_list);
if (older_than_this &&
inode_dirtied_after(inode, *older_than_this))
break;
- list_move(&inode->i_list, dispatch_queue);
+ if (sb && sb != inode->i_sb)
+ do_sb_sort = 1;
+ sb = inode->i_sb;
+ list_move(&inode->i_list, &tmp);
+ }
+
+ /* just one sb in list, splice to dispatch_queue and we're done */
+ if (!do_sb_sort) {
+ list_splice(&tmp, dispatch_queue);
+ return;
+ }
+
+ /* Move inodes from one superblock together */
+ while (!list_empty(&tmp)) {
+ inode = list_entry(tmp.prev, struct inode, i_list);
+ sb = inode->i_sb;
+ list_for_each_prev_safe(pos, node, &tmp) {
+ inode = list_entry(pos, struct inode, i_list);
+ if (inode->i_sb == sb)
+ list_move(&inode->i_list, dispatch_queue);
+ }
}
}
spin_lock(&inode_lock);
inode->i_state &= ~I_SYNC;
if (!(inode->i_state & (I_FREEING | I_CLEAR))) {
- if (inode->i_state & I_DIRTY) {
+ if ((inode->i_state & I_DIRTY_PAGES) && wbc->for_kupdate) {
/*
- * Someone redirtied the inode while were writing back
- * the pages.
+ * More pages get dirtied by a fast dirtier.
+ */
+ goto select_queue;
+ } else if (inode->i_state & I_DIRTY) {
+ /*
+ * At least XFS will redirty the inode during the
+ * writeback (delalloc) and on io completion (isize).
*/
redirty_tail(inode);
} else if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
* soon as the queue becomes uncongested.
*/
inode->i_state |= I_DIRTY_PAGES;
+select_queue:
if (wbc->nr_to_write <= 0) {
/*
* slice used up: queue for next turn
return ret;
}
+static void unpin_sb_for_writeback(struct super_block **psb)
+{
+ struct super_block *sb = *psb;
+
+ if (sb) {
+ up_read(&sb->s_umount);
+ put_super(sb);
+ *psb = NULL;
+ }
+}
+
/*
* For WB_SYNC_NONE writeback, the caller does not have the sb pinned
* before calling writeback. So make sure that we do pin it, so it doesn't
* 1 if we failed.
*/
static int pin_sb_for_writeback(struct writeback_control *wbc,
- struct inode *inode)
+ struct inode *inode, struct super_block **psb)
{
struct super_block *sb = inode->i_sb;
/*
+ * If this sb is already pinned, nothing more to do. If not and
+ * *psb is non-NULL, unpin the old one first
+ */
+ if (sb == *psb)
+ return 0;
+ else if (*psb)
+ unpin_sb_for_writeback(psb);
+
+ /*
* Caller must already hold the ref for this
*/
if (wbc->sync_mode == WB_SYNC_ALL) {
if (down_read_trylock(&sb->s_umount)) {
if (sb->s_root) {
spin_unlock(&sb_lock);
- return 0;
+ goto pinned;
}
/*
* umounted, drop rwsem again and fall through to failure
sb->s_count--;
spin_unlock(&sb_lock);
return 1;
-}
-
-static void unpin_sb_for_writeback(struct writeback_control *wbc,
- struct inode *inode)
-{
- struct super_block *sb = inode->i_sb;
-
- if (wbc->sync_mode == WB_SYNC_ALL)
- return;
-
- up_read(&sb->s_umount);
- put_super(sb);
+pinned:
+ *psb = sb;
+ return 0;
}
static void writeback_inodes_wb(struct bdi_writeback *wb,
struct writeback_control *wbc)
{
- struct super_block *sb = wbc->sb;
- const int is_blkdev_sb = sb_is_blkdev_sb(sb);
+ struct super_block *sb = wbc->sb, *pin_sb = NULL;
const unsigned long start = jiffies; /* livelock avoidance */
spin_lock(&inode_lock);
continue;
}
- if (!bdi_cap_writeback_dirty(wb->bdi)) {
- redirty_tail(inode);
- if (is_blkdev_sb) {
- /*
- * Dirty memory-backed blockdev: the ramdisk
- * driver does this. Skip just this inode
- */
- continue;
- }
- /*
- * Dirty memory-backed inode against a filesystem other
- * than the kernel-internal bdev filesystem. Skip the
- * entire superblock.
- */
- break;
- }
-
if (inode->i_state & (I_NEW | I_WILL_FREE)) {
requeue_io(inode);
continue;
}
- if (wbc->nonblocking && bdi_write_congested(wb->bdi)) {
- wbc->encountered_congestion = 1;
- if (!is_blkdev_sb)
- break; /* Skip a congested fs */
- requeue_io(inode);
- continue; /* Skip a congested blockdev */
- }
-
/*
* Was this inode dirtied after sync_sb_inodes was called?
* This keeps sync from extra jobs and livelock.
if (inode_dirtied_after(inode, start))
break;
- if (pin_sb_for_writeback(wbc, inode)) {
+ if (pin_sb_for_writeback(wbc, inode, &pin_sb)) {
requeue_io(inode);
continue;
}
__iget(inode);
pages_skipped = wbc->pages_skipped;
writeback_single_inode(inode, wbc);
- unpin_sb_for_writeback(wbc, inode);
if (wbc->pages_skipped != pages_skipped) {
/*
* writeback is not making progress due to locked
wbc->more_io = 1;
}
+ unpin_sb_for_writeback(&pin_sb);
+
spin_unlock(&inode_lock);
/* Leave any unwritten inodes on b_io */
}
.sync_mode = args->sync_mode,
.older_than_this = NULL,
.for_kupdate = args->for_kupdate,
+ .for_background = args->for_background,
.range_cyclic = args->range_cyclic,
};
unsigned long oldest_jif;
break;
wbc.more_io = 0;
- wbc.encountered_congestion = 0;
wbc.nr_to_write = MAX_WRITEBACK_PAGES;
wbc.pages_skipped = 0;
writeback_inodes_wb(wb, &wbc);
nr_to_write = nr_dirty + nr_unstable +
(inodes_stat.nr_inodes - inodes_stat.nr_unused);
- bdi_writeback_all(sb, nr_to_write);
+ bdi_start_writeback(sb->s_bdi, sb, nr_to_write);
}
EXPORT_SYMBOL(writeback_inodes_sb);
/**
+ * writeback_inodes_sb_if_idle - start writeback if none underway
+ * @sb: the superblock
+ *
+ * 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)
+{
+ if (!writeback_in_progress(sb->s_bdi)) {
+ writeback_inodes_sb(sb);
+ return 1;
+ } else
+ return 0;
+}
+EXPORT_SYMBOL(writeback_inodes_sb_if_idle);
+
+/**
* sync_inodes_sb - sync sb inode pages
* @sb: the superblock
*
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff