@@ -8148,9 +8148,11 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
u64 file_offset = dip->logical_offset;
u64 submit_len = 0;
u64 map_length;
- int nr_pages = 0;
- int ret;
+ u32 blocksize = root->sectorsize;
int async_submit = 0;
+ int nr_sectors;
+ int ret;
+ int i;
map_length = orig_bio->bi_iter.bi_size;
ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
@@ -8180,9 +8182,12 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
atomic_inc(&dip->pending_bios);
while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
- if (map_length < submit_len + bvec->bv_len ||
- bio_add_page(bio, bvec->bv_page, bvec->bv_len,
- bvec->bv_offset) < bvec->bv_len) {
+ nr_sectors = bvec->bv_len >> inode->i_blkbits;
+ i = 0;
+next_block:
+ if (unlikely(map_length < submit_len + blocksize ||
+ bio_add_page(bio, bvec->bv_page, blocksize,
+ bvec->bv_offset + (i * blocksize)) < blocksize)) {
/*
* inc the count before we submit the bio so
* we know the end IO handler won't happen before
@@ -8203,7 +8208,6 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
file_offset += submit_len;
submit_len = 0;
- nr_pages = 0;
bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
start_sector, GFP_NOFS);
@@ -8221,9 +8225,14 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
bio_put(bio);
goto out_err;
}
+
+ goto next_block;
} else {
- submit_len += bvec->bv_len;
- nr_pages++;
+ submit_len += blocksize;
+ if (--nr_sectors) {
+ i++;
+ goto next_block;
+ }
bvec++;
}
}
In subpagesize-blocksize scenario, map_length can be less than the length of a bio vector. Such a condition may cause btrfs_submit_direct_hook() to submit a zero length bio. Fix this by comparing map_length against block size rather than with bv_len. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> --- fs/btrfs/inode.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-)