Btrfs: change how we iterate bios in endio
Since dio submit has used bio_clone_fast, the submitted bio may not have a
reliable bi_vcnt, for the bio vector iterations in checksum related
functions, bio->bi_iter is not modified yet and it's safe to use
bio_for_each_segment, while for those bio vector iterations in dio read's
endio, we now save a copy of bvec_iter in struct btrfs_io_bio when cloning
bios and use the helper __bio_for_each_segment with the saved bvec_iter to
access each bvec.
Also for dio reads which don't get split, we also need to save a copy of
bio iterator in btrfs_bio_clone to let __bio_for_each_segments to access
each bvec in dio read's endio. Note that it doesn't affect other calls of
btrfs_bio_clone() because they don't need to use this iterator.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 64fcb31..9f6062c 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -164,7 +164,8 @@ static int __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
u64 logical_offset, u32 *dst, int dio)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
- struct bio_vec *bvec;
+ struct bio_vec bvec;
+ struct bvec_iter iter;
struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
struct btrfs_csum_item *item = NULL;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
@@ -177,7 +178,7 @@ static int __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
u64 page_bytes_left;
u32 diff;
int nblocks;
- int count = 0, i;
+ int count = 0;
u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
path = btrfs_alloc_path();
@@ -206,8 +207,6 @@ static int __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
if (bio->bi_iter.bi_size > PAGE_SIZE * 8)
path->reada = READA_FORWARD;
- WARN_ON(bio->bi_vcnt <= 0);
-
/*
* the free space stuff is only read when it hasn't been
* updated in the current transaction. So, we can safely
@@ -223,13 +222,13 @@ static int __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
if (dio)
offset = logical_offset;
- bio_for_each_segment_all(bvec, bio, i) {
- page_bytes_left = bvec->bv_len;
+ bio_for_each_segment(bvec, bio, iter) {
+ page_bytes_left = bvec.bv_len;
if (count)
goto next;
if (!dio)
- offset = page_offset(bvec->bv_page) + bvec->bv_offset;
+ offset = page_offset(bvec.bv_page) + bvec.bv_offset;
count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
(u32 *)csum, nblocks);
if (count)
@@ -440,15 +439,15 @@ int btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
struct btrfs_ordered_sum *sums;
struct btrfs_ordered_extent *ordered = NULL;
char *data;
- struct bio_vec *bvec;
+ struct bvec_iter iter;
+ struct bio_vec bvec;
int index;
int nr_sectors;
- int i, j;
unsigned long total_bytes = 0;
unsigned long this_sum_bytes = 0;
+ int i;
u64 offset;
- WARN_ON(bio->bi_vcnt <= 0);
sums = kzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
GFP_NOFS);
if (!sums)
@@ -465,19 +464,19 @@ int btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
index = 0;
- bio_for_each_segment_all(bvec, bio, j) {
+ bio_for_each_segment(bvec, bio, iter) {
if (!contig)
- offset = page_offset(bvec->bv_page) + bvec->bv_offset;
+ offset = page_offset(bvec.bv_page) + bvec.bv_offset;
if (!ordered) {
ordered = btrfs_lookup_ordered_extent(inode, offset);
BUG_ON(!ordered); /* Logic error */
}
- data = kmap_atomic(bvec->bv_page);
+ data = kmap_atomic(bvec.bv_page);
nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info,
- bvec->bv_len + fs_info->sectorsize
+ bvec.bv_len + fs_info->sectorsize
- 1);
for (i = 0; i < nr_sectors; i++) {
@@ -504,12 +503,12 @@ int btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
+ total_bytes;
index = 0;
- data = kmap_atomic(bvec->bv_page);
+ data = kmap_atomic(bvec.bv_page);
}
sums->sums[index] = ~(u32)0;
sums->sums[index]
- = btrfs_csum_data(data + bvec->bv_offset
+ = btrfs_csum_data(data + bvec.bv_offset
+ (i * fs_info->sectorsize),
sums->sums[index],
fs_info->sectorsize);