From: Qu Wenruo wqu@suse.com
commit 3065976b045f77a910809fa7699f99a1e7c0dbbb upstream.
Since now flush_write_bio() could return error, kill the BUG_ON() first. Then don't call flush_write_bio() unconditionally, instead we check the return value from __extent_writepage() first.
If __extent_writepage() fails, we do cleanup, and return error without submitting the possible corrupted or half-baked bio.
If __extent_writepage() successes, then we call flush_write_bio() and return the result.
Signed-off-by: Qu Wenruo wqu@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/extent_io.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)
--- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -160,6 +160,16 @@ static int __must_check submit_one_bio(s return blk_status_to_errno(ret); }
+/* Cleanup unsubmitted bios */ +static void end_write_bio(struct extent_page_data *epd, int ret) +{ + if (epd->bio) { + epd->bio->bi_status = errno_to_blk_status(ret); + bio_endio(epd->bio); + epd->bio = NULL; + } +} + /* * Submit bio from extent page data via submit_one_bio * @@ -3461,6 +3471,9 @@ done: * records are inserted to lock ranges in the tree, and as dirty areas * are found, they are marked writeback. Then the lock bits are removed * and the end_io handler clears the writeback ranges + * + * Return 0 if everything goes well. + * Return <0 for error. */ static int __extent_writepage(struct page *page, struct writeback_control *wbc, struct extent_page_data *epd) @@ -3528,6 +3541,7 @@ done: end_extent_writepage(page, ret, start, page_end); } unlock_page(page); + ASSERT(ret <= 0); return ret;
done_unlocked: @@ -4067,7 +4081,6 @@ retry: int extent_write_full_page(struct page *page, struct writeback_control *wbc) { int ret; - int flush_ret; struct extent_page_data epd = { .bio = NULL, .tree = &BTRFS_I(page->mapping->host)->io_tree, @@ -4076,9 +4089,14 @@ int extent_write_full_page(struct page * };
ret = __extent_writepage(page, wbc, &epd); + ASSERT(ret <= 0); + if (ret < 0) { + end_write_bio(&epd, ret); + return ret; + }
- flush_ret = flush_write_bio(&epd); - BUG_ON(flush_ret < 0); + ret = flush_write_bio(&epd); + ASSERT(ret <= 0); return ret; }