From: Josef Bacik josef@toxicpanda.com
[ Upstream commit f9f15de85d74e7eef021af059ca53a15f041cdd8 ]
I hit some weird panics while fixing up the error handling from btrfs_lookup_bio_sums(). Turns out the compression path will complete the bio we use if we set up any of the compression bios and then return an error, and then btrfs_submit_data_bio() will also call bio_endio() on the bio.
Fix this by making btrfs_submit_compressed_read() responsible for calling bio_endio() on the bio if there are any errors. Currently it was only doing it if we created the compression bios, otherwise it was depending on btrfs_submit_data_bio() to do the right thing. This creates the above problem, so fix up btrfs_submit_compressed_read() to always call bio_endio() in case of an error, and then simply return from btrfs_submit_data_bio() if we had to call btrfs_submit_compressed_read().
Signed-off-by: Josef Bacik josef@toxicpanda.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/compression.c | 20 ++++++++++++++------ fs/btrfs/inode.c | 8 +++++++- 2 files changed, 21 insertions(+), 7 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 8b3bca269de3..59f50d362db3 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -808,7 +808,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, u64 em_len; u64 em_start; struct extent_map *em; - blk_status_t ret = BLK_STS_RESOURCE; + blk_status_t ret; int faili = 0; u8 *sums;
@@ -821,14 +821,18 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, file_offset, fs_info->sectorsize); read_unlock(&em_tree->lock); - if (!em) - return BLK_STS_IOERR; + if (!em) { + ret = BLK_STS_IOERR; + goto out; + }
ASSERT(em->compress_type != BTRFS_COMPRESS_NONE); compressed_len = em->block_len; cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS); - if (!cb) + if (!cb) { + ret = BLK_STS_RESOURCE; goto out; + }
refcount_set(&cb->pending_sectors, compressed_len >> fs_info->sectorsize_bits); cb->errors = 0; @@ -851,8 +855,10 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, nr_pages = DIV_ROUND_UP(compressed_len, PAGE_SIZE); cb->compressed_pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); - if (!cb->compressed_pages) + if (!cb->compressed_pages) { + ret = BLK_STS_RESOURCE; goto fail1; + }
for (pg_index = 0; pg_index < nr_pages; pg_index++) { cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS); @@ -938,7 +944,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, comp_bio = NULL; } } - return 0; + return BLK_STS_OK;
fail2: while (faili >= 0) { @@ -951,6 +957,8 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, kfree(cb); out: free_extent_map(em); + bio->bi_status = ret; + bio_endio(bio); return ret; finish_cb: if (comp_bio) { diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 826f94b2fda5..5aace4c13519 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2538,10 +2538,15 @@ blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio, goto out;
if (bio_flags & EXTENT_BIO_COMPRESSED) { + /* + * btrfs_submit_compressed_read will handle completing + * the bio if there were any errors, so just return + * here. + */ ret = btrfs_submit_compressed_read(inode, bio, mirror_num, bio_flags); - goto out; + goto out_no_endio; } else { /* * Lookup bio sums does extra checks around whether we @@ -2575,6 +2580,7 @@ blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio, bio->bi_status = ret; bio_endio(bio); } +out_no_endio: return ret; }