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| author | Takafumi Kubota <takafumi.kubota1012@sslab.ics.keio.ac.jp> | 2017-02-09 17:24:33 +0900 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2017-02-17 12:03:47 +0100 |
| commit | fe01aa65385c226d822013b90608b67c485f8dc6 (patch) | |
| tree | 2bcc1b1153f87035b1cac8380007010e1564076b /fs/btrfs | |
| parent | 66bbc1c0c0b283600abd187bf8c8c25ab7549307 (diff) | |
| download | linux-fe01aa65385c226d822013b90608b67c485f8dc6.tar.bz2 | |
Btrfs: add another missing end_page_writeback on submit_extent_page failure
If btrfs_bio_alloc fails in submit_extent_page, submit_extent_page returns
without clearing the writeback bit of the failed page.
__extent_writepage_io, that is a caller of submit_extent_page,
does not clear the remaining writeback bit anywhere.
As a result, this will cause the hang at filemap_fdatawait_range,
because it waits the writeback bit to be cleared from the failed page.
So, we have to call end_page_writeback to clear the writeback bit.
For reproducing the hang, we inject a fault like
if (should_failtest()) { // I define should_failtest()
bio = NULL;
}
else {
bio = btrfs_bio_alloc(...);
}
in submit_extent_page.
We should also check whether page has the bit before end_page_writeback,
to avoid the conflict against the other end_page_writeback in bio_endio.
Thus, we add PageWriteback checks not only in __extent_writepage_io,
but also in write_one_eb too, because it misses the check.
Signed-off-by: Takafumi Kubota <takafumi.kubota1012@sslab.ics.keio.ac.jp>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/extent_io.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 4a8b119655d5..9df6ed30de00 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3437,8 +3437,11 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode, bdev, &epd->bio, max_nr, end_bio_extent_writepage, 0, 0, 0, false); - if (ret) + if (ret) { SetPageError(page); + if (PageWriteback(page)) + end_page_writeback(page); + } cur = cur + iosize; pg_offset += iosize; @@ -3754,7 +3757,8 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb, epd->bio_flags = bio_flags; if (ret) { set_btree_ioerr(p); - end_page_writeback(p); + if (PageWriteback(p)) + end_page_writeback(p); if (atomic_sub_and_test(num_pages - i, &eb->io_pages)) end_extent_buffer_writeback(eb); ret = -EIO; |