btrfs: remove the alignment checks in end_bbio_data_read()

end_bbio_data_read() checks that each iterated folio fragment is aligned
and justifies that with block drivers advancing the bio.  But block
driver only advance bi_iter, while end_bbio_data_read() uses
bio_for_each_folio_all() to iterate the immutable bi_io_vec array that
can't be changed by drivers at all.

Furthermore btrfs has already did the alignment check of the file
offset inside submit_one_sector(), and the size is fixed to fs block
size, there is no need to re-do the alignment check again inside the
endio function.

So just remove the unnecessary alignment check along with the incorrect
comment.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 6c434d6766d6762d0e4f08c6c014b5d37f31ac15..42e985826602c9aab24d625503fa252298092ccf 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -501,43 +501,22 @@ static void end_bbio_data_read(struct btrfs_bio *bbio)
        struct btrfs_fs_info *fs_info = bbio->fs_info;
        struct bio *bio = &bbio->bio;
        struct folio_iter fi;
-       const u32 sectorsize = fs_info->sectorsize;
 
        ASSERT(!bio_flagged(bio, BIO_CLONED));
        bio_for_each_folio_all(fi, &bbio->bio) {
                bool uptodate = !bio->bi_status;
                struct folio *folio = fi.folio;
                struct inode *inode = folio->mapping->host;
-               u64 start;
-               u64 end;
-               u32 len;
+               u64 start = folio_pos(folio) + fi.offset;
 
                btrfs_debug(fs_info,
                        "%s: bi_sector=%llu, err=%d, mirror=%u",
                        __func__, bio->bi_iter.bi_sector, bio->bi_status,
                        bbio->mirror_num);
 
-               /*
-                * We always issue full-sector reads, but if some block in a
-                * folio fails to read, blk_update_request() will advance
-                * bv_offset and adjust bv_len to compensate.  Print a warning
-                * for unaligned offsets, and an error if they don't add up to
-                * a full sector.
-                */
-               if (!IS_ALIGNED(fi.offset, sectorsize))
-                       btrfs_err(fs_info,
-               "partial page read in btrfs with offset %zu and length %zu",
-                                 fi.offset, fi.length);
-               else if (!IS_ALIGNED(fi.offset + fi.length, sectorsize))
-                       btrfs_info(fs_info,
-               "incomplete page read with offset %zu and length %zu",
-                                  fi.offset, fi.length);
-
-               start = folio_pos(folio) + fi.offset;
-               end = start + fi.length - 1;
-               len = fi.length;
 
                if (likely(uptodate)) {
+                       u64 end = start + fi.length - 1;
                        loff_t i_size = i_size_read(inode);
 
                        /*
@@ -562,7 +541,7 @@ static void end_bbio_data_read(struct btrfs_bio *bbio)
                }
 
                /* Update page status and unlock. */
-               end_folio_read(folio, uptodate, start, len);
+               end_folio_read(folio, uptodate, start, fi.length);
        }
        bio_put(bio);
 }