From 6853c64a6e763fedfeef214569ceea40008cc007 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 27 Sep 2021 15:21:51 +0800 Subject: btrfs: handle errors properly inside btrfs_submit_compressed_write() Just like btrfs_submit_compressed_read(), there are quite some BUG_ON()s inside btrfs_submit_compressed_write() for the bio submission path. Fix them using the same method: - For last bio, just endio the bio As in that case, one of the endio function of all these submitted bio will be able to free the compressed_bio - For half-submitted bio, wait and finish the compressed_bio manually In this case, as long as all other bio finish, we're the only one referring the compressed bio, and can manually finish it. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/compression.c | 98 +++++++++++++++++++++++++++++++------------------- 1 file changed, 62 insertions(+), 36 deletions(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index f7a6c3cda85e..dabb3a88f2e5 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -366,50 +366,55 @@ static noinline void end_compressed_writeback(struct inode *inode, /* the inode may be gone now */ } -/* - * do the cleanup once all the compressed pages hit the disk. - * This will clear writeback on the file pages and free the compressed - * pages. - * - * This also calls the writeback end hooks for the file pages so that - * metadata and checksums can be updated in the file. - */ -static void end_compressed_bio_write(struct bio *bio) +static void finish_compressed_bio_write(struct compressed_bio *cb) { - struct compressed_bio *cb = bio->bi_private; - struct inode *inode; - struct page *page; + struct inode *inode = cb->inode; unsigned int index; - if (!dec_and_test_compressed_bio(cb, bio)) - goto out; - - /* ok, we're the last bio for this extent, step one is to - * call back into the FS and do all the end_io operations + /* + * Ok, we're the last bio for this extent, step one is to call back + * into the FS and do all the end_io operations. */ - inode = cb->inode; - btrfs_record_physical_zoned(inode, cb->start, bio); btrfs_writepage_endio_finish_ordered(BTRFS_I(inode), NULL, cb->start, cb->start + cb->len - 1, !cb->errors); end_compressed_writeback(inode, cb); - /* note, our inode could be gone now */ + /* Note, our inode could be gone now */ /* - * release the compressed pages, these came from alloc_page and + * Release the compressed pages, these came from alloc_page and * are not attached to the inode at all */ - index = 0; for (index = 0; index < cb->nr_pages; index++) { - page = cb->compressed_pages[index]; + struct page *page = cb->compressed_pages[index]; + page->mapping = NULL; put_page(page); } - /* finally free the cb struct */ + /* Finally free the cb struct */ kfree(cb->compressed_pages); kfree(cb); +} + +/* + * Do the cleanup once all the compressed pages hit the disk. This will clear + * writeback on the file pages and free the compressed pages. + * + * This also calls the writeback end hooks for the file pages so that metadata + * and checksums can be updated in the file. + */ +static void end_compressed_bio_write(struct bio *bio) +{ + struct compressed_bio *cb = bio->bi_private; + + if (!dec_and_test_compressed_bio(cb, bio)) + goto out; + + btrfs_record_physical_zoned(cb->inode, cb->start, bio); + + finish_compressed_bio_write(cb); out: bio_put(bio); } @@ -512,18 +517,18 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, atomic_inc(&cb->pending_bios); ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA); - BUG_ON(ret); /* -ENOMEM */ + if (ret) + goto finish_cb; if (!skip_sum) { ret = btrfs_csum_one_bio(inode, bio, start, 1); - BUG_ON(ret); /* -ENOMEM */ + if (ret) + goto finish_cb; } ret = btrfs_map_bio(fs_info, bio, 0); - if (ret) { - bio->bi_status = ret; - bio_endio(bio); - } + if (ret) + goto finish_cb; bio = btrfs_bio_alloc(BIO_MAX_VECS); bio->bi_iter.bi_sector = first_byte >> SECTOR_SHIFT; @@ -550,23 +555,44 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, atomic_inc(&cb->pending_bios); ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA); - BUG_ON(ret); /* -ENOMEM */ + if (ret) + goto last_bio; if (!skip_sum) { ret = btrfs_csum_one_bio(inode, bio, start, 1); - BUG_ON(ret); /* -ENOMEM */ + if (ret) + goto last_bio; } ret = btrfs_map_bio(fs_info, bio, 0); - if (ret) { - bio->bi_status = ret; - bio_endio(bio); - } + if (ret) + goto last_bio; if (blkcg_css) kthread_associate_blkcg(NULL); return 0; +last_bio: + bio->bi_status = ret; + /* One of the bios' endio function will free @cb. */ + bio_endio(bio); + return ret; + +finish_cb: + if (bio) { + bio->bi_status = ret; + bio_endio(bio); + } + + wait_var_event(cb, atomic_read(&cb->pending_bios) == 0); + /* + * Even with previous bio ended, we should still have io not yet + * submitted, thus need to finish manually. + */ + ASSERT(refcount_read(&cb->pending_sectors)); + /* Now we are the only one referring @cb, can finish it safely. */ + finish_compressed_bio_write(cb); + return ret; } static u64 bio_end_offset(struct bio *bio) -- cgit v1.2.3