The io_bio tracks checksums and has an inline buffer or an allocated
one. And there's a third member that points to the right one, but we
don't need to use an extra pointer for that. Let btrfs_io_bio::csum
point to the right buffer and check that the inline buffer is not
accidentally freed.
This shrinks struct btrfs_io_bio by 8 bytes.
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
---
fs/btrfs/file-item.c | 12 +++++++-----
fs/btrfs/volumes.h | 1 -
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index ba74827beb32..1f2d0a6ab634 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -144,7 +144,10 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
static void btrfs_io_bio_endio_readpage(struct btrfs_io_bio *bio, int err)
{
- kfree(bio->csum_allocated);
+ if (bio->csum != bio->csum_inline) {
+ kfree(bio->csum);
+ bio->csum = NULL;
+ }
}
static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
@@ -175,13 +178,12 @@ static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio
nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
if (!dst) {
if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
- btrfs_bio->csum_allocated = kmalloc_array(nblocks,
- csum_size, GFP_NOFS);
- if (!btrfs_bio->csum_allocated) {
+ btrfs_bio->csum = kmalloc_array(nblocks, csum_size,
+ GFP_NOFS);
+ if (!btrfs_bio->csum) {
btrfs_free_path(path);
return BLK_STS_RESOURCE;
}
- btrfs_bio->csum = btrfs_bio->csum_allocated;
btrfs_bio->end_io = btrfs_io_bio_endio_readpage;
} else {
btrfs_bio->csum = btrfs_bio->csum_inline;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 1d936ce282c3..9a764f2d462e 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -274,7 +274,6 @@ struct btrfs_io_bio {
u64 logical;
u8 *csum;
u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
- u8 *csum_allocated;
btrfs_io_bio_end_io_t *end_io;
struct bvec_iter iter;
/*
--
2.19.1
