Btrfs: fix kernel oops while reading compressed data
The kernel oops happens at
kernel BUG at fs/btrfs/extent_io.c:2104!
...
RIP: clean_io_failure+0x263/0x2a0 [btrfs]
It's showing that read-repair code is using an improper mirror index.
This is due to the fact that compression read's endio hasn't recorded
the failed mirror index in %cb->orig_bio.
With this, btrfs's read-repair can work properly on reading compressed
data.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reported-by: Paul Jones <paul@pauljones.id.au>
Tested-by: Paul Jones <paul@pauljones.id.au>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 883ecc5..c6aa53c 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -107,6 +107,7 @@ static void end_compressed_bio_read(struct bio *bio)
struct inode *inode;
struct page *page;
unsigned long index;
+ unsigned int mirror = btrfs_io_bio(bio)->mirror_num;
int ret;
if (bio->bi_status)
@@ -118,6 +119,14 @@ static void end_compressed_bio_read(struct bio *bio)
if (!refcount_dec_and_test(&cb->pending_bios))
goto out;
+ /*
+ * Record the correct mirror_num in cb->orig_bio so that
+ * read-repair can work properly.
+ */
+ ASSERT(btrfs_io_bio(cb->orig_bio));
+ btrfs_io_bio(cb->orig_bio)->mirror_num = mirror;
+ cb->mirror_num = mirror;
+
inode = cb->inode;
ret = check_compressed_csum(BTRFS_I(inode), cb,
(u64)bio->bi_iter.bi_sector << 9);
