[PATCH v1 51/54] btrfs: avoid access to .bi_vcnt directly
From: Ming Lei
Date: Tue Dec 27 2016 - 11:08:00 EST
BTRFS uses bio->bi_vcnt to figure out page numbers, this
way becomes not correct once we start to support multipage
bvec.
So use bio_segments_all() instead.
Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
---
fs/btrfs/check-integrity.c | 7 ++++---
fs/btrfs/extent_io.c | 9 ++++++---
fs/btrfs/extent_io.h | 1 +
fs/btrfs/inode.c | 2 +-
4 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index e3cc7b18fe8b..9c184a61e098 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -2829,17 +2829,18 @@ static void __btrfsic_submit_bio(struct bio *bio)
int bio_is_patched;
char **mapped_datav;
struct bvec_iter_all bia;
+ unsigned num_pages = bio_segments_all(bio);
dev_bytenr = 512 * bio->bi_iter.bi_sector;
bio_is_patched = 0;
if (dev_state->state->print_mask &
BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
pr_info("submit_bio(rw=%d,0x%x, bi_vcnt=%u, bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n",
- bio_op(bio), bio->bi_opf, bio->bi_vcnt,
+ bio_op(bio), bio->bi_opf, num_pages,
(unsigned long long)bio->bi_iter.bi_sector,
dev_bytenr, bio->bi_bdev);
- mapped_datav = kmalloc_array(bio->bi_vcnt,
+ mapped_datav = kmalloc_array(num_pages,
sizeof(*mapped_datav), GFP_NOFS);
if (!mapped_datav)
goto leave;
@@ -2856,7 +2857,7 @@ static void __btrfsic_submit_bio(struct bio *bio)
cur_bytenr += bvec->bv_len;
}
btrfsic_process_written_block(dev_state, dev_bytenr,
- mapped_datav, bio->bi_vcnt,
+ mapped_datav, num_pages,
bio, &bio_is_patched,
NULL, bio->bi_opf);
bio_for_each_segment_all_sp(bvec, bio, i, bia)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 137f95063c85..3c021f4dd8bf 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2273,6 +2273,7 @@ int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
}
int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
+ unsigned num_pages,
struct io_failure_record *failrec, int failed_mirror)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -2296,7 +2297,7 @@ int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
* a) deliver good data to the caller
* b) correct the bad sectors on disk
*/
- if (failed_bio->bi_vcnt > 1) {
+ if (num_pages > 1) {
/*
* to fulfill b), we need to know the exact failing sectors, as
* we don't want to rewrite any more than the failed ones. thus,
@@ -2390,6 +2391,7 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
struct bio *bio;
int read_mode = 0;
int ret;
+ unsigned num_pages = bio_segments_all(failed_bio);
BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
@@ -2397,13 +2399,14 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
if (ret)
return ret;
- ret = btrfs_check_repairable(inode, failed_bio, failrec, failed_mirror);
+ ret = btrfs_check_repairable(inode, failed_bio, num_pages, failrec,
+ failed_mirror);
if (!ret) {
free_io_failure(inode, failrec);
return -EIO;
}
- if (failed_bio->bi_vcnt > 1)
+ if (num_pages > 1)
read_mode |= REQ_FAILFAST_DEV;
phy_offset >>= inode->i_sb->s_blocksize_bits;
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 17f9ce479ed7..8fce380bc8d7 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -483,6 +483,7 @@ void btrfs_free_io_failure_record(struct inode *inode, u64 start, u64 end);
int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
struct io_failure_record **failrec_ret);
int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
+ unsigned num_pages,
struct io_failure_record *failrec, int fail_mirror);
struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
struct io_failure_record *failrec,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 544e1cf9a552..fa77cb210907 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7914,7 +7914,7 @@ static int dio_read_error(struct inode *inode, struct bio *failed_bio,
return -EIO;
}
- if ((failed_bio->bi_vcnt > 1)
+ if ((bio_segments_all(failed_bio) > 1)
|| (failed_bio->bi_io_vec->bv_len
> btrfs_inode_sectorsize(inode)))
read_mode |= REQ_FAILFAST_DEV;
--
2.7.4