[PATCH v2 18/26] btrfs: make btrfs_submit_compressed_write() to be subpage compatible

Qu Wenruo
2021-08-29T05:25:26Z

There is a WARN_ON() checking if @start is aligned to PAGE_SIZE, not
sectorsize, which will cause false alert for subpage.

Fix it to check against sectorsize.

Furthermore:

- Use ASSERT() to do the check
So that in the future we may skip the check for production build

- Also check alignment for @len

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
fs/btrfs/compression.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 6e389f1c6091..6bfa626bbd0b 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -504,7 +504,8 @@ blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
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));
+ ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
+ IS_ALIGNED(len, fs_info->sectorsize));
cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS);
if (!cb)
return BLK_STS_RESOURCE;
--
2.32.0