path: root/fs/btrfs/extent_io.h
diff options
authorJeff Mahoney <jeffm@suse.com>2012-02-15 16:23:57 +0100
committerDavid Sterba <dsterba@suse.cz>2012-02-15 16:40:25 +0100
commit87826df0ec36fc28884b4ddbb3f3af41c4c2008f (patch)
tree7d95bf1ff03c82805903330a279a67642be68699 /fs/btrfs/extent_io.h
parenta7e221e9002306a753d6f78b4060edabce402033 (diff)
btrfs: delalloc for page dirtied out-of-band in fixup worker
We encountered an issue that was easily observable on s/390 systems but could really happen anywhere. The timing just seemed to hit reliably on s/390 with limited memory. The gist is that when an unexpected set_page_dirty() happened, we'd run into the BUG() in btrfs_writepage_fixup_worker since it wasn't properly set up for delalloc. This patch does the following: - Performs the missing delalloc in the fixup worker - Allow the start hook to return -EBUSY which informs __extent_writepage that it should mark the page skipped and not to redirty it. This is required since the fixup worker can fail with -ENOSPC and the page will have already been redirtied. That causes an Oops in drop_outstanding_extents later. Retrying the fixup worker could lead to an infinite loop. Deferring the page redirty also saves us some cycles since the page would be stuck in a resubmit-redirty loop until the fixup worker completes. It's not harmful, just wasteful. - If the fixup worker fails, we mark the page and mapping as errored, and end the writeback, similar to what we would do had the page actually been submitted to writeback. Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Diffstat (limited to 'fs/btrfs/extent_io.h')
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index bc6a042cb6f..cecc3518c12 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -319,4 +319,5 @@ struct btrfs_mapping_tree;
int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
u64 length, u64 logical, struct page *page,
int mirror_num);
+int end_extent_writepage(struct page *page, int err, u64 start, u64 end);