writeback: Update dirty flags in two steps
Filesystems with delalloc support may dirty inode during writepages.
As result inode will have dirty metadata flags even after write_inode.
In fact we have two dedicated functions for proper data and metadata
writeback. It is reasonable to separate flags updates in two stages.
https://bugzilla.kernel.org/show_bug.cgi?id=15906
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 67db897..0f62957 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -460,11 +460,9 @@
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);
@@ -480,6 +478,15 @@
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);