From: Johannes Thumshirn johannes.thumshirn@wdc.com
commit 764c7c9a464b68f7c6a5a9ec0b923176a05e8e8f upstream.
When multiple processes write data to the same block group on a compressed zoned filesystem, the underlying device could report I/O errors and data corruption is possible.
This happens because on a zoned file system, compressed data writes where sent to the device via a REQ_OP_WRITE instead of a REQ_OP_ZONE_APPEND operation. But with REQ_OP_WRITE and parallel submission it cannot be guaranteed that the data is always submitted aligned to the underlying zone's write pointer.
The change to using REQ_OP_ZONE_APPEND instead of REQ_OP_WRITE on a zoned filesystem is non intrusive on a regular file system or when submitting to a conventional zone on a zoned filesystem, as it is guarded by btrfs_use_zone_append.
Reported-by: David Sterba dsterba@suse.com Fixes: 9d294a685fbc ("btrfs: zoned: enable to mount ZONED incompat flag") CC: stable@vger.kernel.org # 5.12.x: e380adfc213a13: btrfs: zoned: pass start block to btrfs_use_zone_append CC: stable@vger.kernel.org # 5.12.x Signed-off-by: Johannes Thumshirn johannes.thumshirn@wdc.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/compression.c | 42 ++++++++++++++++++++++++++++++++++++++---- 1 file changed, 38 insertions(+), 4 deletions(-)
--- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -28,6 +28,7 @@ #include "compression.h" #include "extent_io.h" #include "extent_map.h" +#include "zoned.h"
static const char* const btrfs_compress_types[] = { "", "zlib", "lzo", "zstd" };
@@ -349,6 +350,7 @@ static void end_compressed_bio_write(str */ inode = cb->inode; cb->compressed_pages[0]->mapping = cb->inode->i_mapping; + btrfs_record_physical_zoned(inode, cb->start, bio); btrfs_writepage_endio_finish_ordered(cb->compressed_pages[0], cb->start, cb->start + cb->len - 1, bio->bi_status == BLK_STS_OK); @@ -401,6 +403,8 @@ blk_status_t btrfs_submit_compressed_wri u64 first_byte = disk_start; blk_status_t ret; int skip_sum = inode->flags & BTRFS_INODE_NODATASUM; + const bool use_append = btrfs_use_zone_append(inode, disk_start); + const unsigned int bio_op = use_append ? REQ_OP_ZONE_APPEND : REQ_OP_WRITE;
WARN_ON(!PAGE_ALIGNED(start)); cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS); @@ -418,10 +422,31 @@ blk_status_t btrfs_submit_compressed_wri cb->nr_pages = nr_pages;
bio = btrfs_bio_alloc(first_byte); - bio->bi_opf = REQ_OP_WRITE | write_flags; + bio->bi_opf = bio_op | write_flags; bio->bi_private = cb; bio->bi_end_io = end_compressed_bio_write;
+ if (use_append) { + struct extent_map *em; + struct map_lookup *map; + struct block_device *bdev; + + em = btrfs_get_chunk_map(fs_info, disk_start, PAGE_SIZE); + if (IS_ERR(em)) { + kfree(cb); + bio_put(bio); + return BLK_STS_NOTSUPP; + } + + map = em->map_lookup; + /* We only support single profile for now */ + ASSERT(map->num_stripes == 1); + bdev = map->stripes[0].dev->bdev; + + bio_set_dev(bio, bdev); + free_extent_map(em); + } + if (blkcg_css) { bio->bi_opf |= REQ_CGROUP_PUNT; kthread_associate_blkcg(blkcg_css); @@ -432,6 +457,7 @@ blk_status_t btrfs_submit_compressed_wri bytes_left = compressed_len; for (pg_index = 0; pg_index < cb->nr_pages; pg_index++) { int submit = 0; + int len;
page = compressed_pages[pg_index]; page->mapping = inode->vfs_inode.i_mapping; @@ -439,9 +465,13 @@ blk_status_t btrfs_submit_compressed_wri submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE, bio, 0);
+ if (pg_index == 0 && use_append) + len = bio_add_zone_append_page(bio, page, PAGE_SIZE, 0); + else + len = bio_add_page(bio, page, PAGE_SIZE, 0); + page->mapping = NULL; - if (submit || bio_add_page(bio, page, PAGE_SIZE, 0) < - PAGE_SIZE) { + if (submit || len < PAGE_SIZE) { /* * inc the count before we submit the bio so * we know the end IO handler won't happen before @@ -465,11 +495,15 @@ blk_status_t btrfs_submit_compressed_wri }
bio = btrfs_bio_alloc(first_byte); - bio->bi_opf = REQ_OP_WRITE | write_flags; + bio->bi_opf = bio_op | write_flags; bio->bi_private = cb; bio->bi_end_io = end_compressed_bio_write; if (blkcg_css) bio->bi_opf |= REQ_CGROUP_PUNT; + /* + * Use bio_add_page() to ensure the bio has at least one + * page. + */ bio_add_page(bio, page, PAGE_SIZE, 0); } if (bytes_left < PAGE_SIZE) {