[PATCH v3 11/49] btrfs: avoid access to .bi_vcnt directly

[PATCH v3 11/49] btrfs: avoid access to .bi_vcnt directly

[Ming Lei]

BTRFS uses bio->bi_vcnt to figure out page numbers, this
way becomes not correct once we start to enable multipage
bvec.

So use bio_for_each_segment_all() to do that instead.

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 fs/btrfs/extent_io.c | 20 ++++++++++++++++----
 fs/btrfs/extent_io.h |  2 +-
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 0aff9b278c19..0e7367817b92 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2258,7 +2258,7 @@ int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
 	return 0;
 }
 
-bool btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
+bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages,
 			   struct io_failure_record *failrec, int failed_mirror)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -2282,7 +2282,7 @@ bool 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 (failed_bio_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,
@@ -2355,6 +2355,17 @@ struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
 	return bio;
 }
 
+static unsigned int get_bio_pages(struct bio *bio)
+{
+	unsigned i;
+	struct bio_vec *bv;
+
+	bio_for_each_segment_all(bv, bio, i)
+		;
+
+	return i;
+}
+
 /*
  * this is a generic handler for readpage errors (default
  * readpage_io_failed_hook). if other copies exist, read those and write back
@@ -2375,6 +2386,7 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
 	int read_mode = 0;
 	blk_status_t status;
 	int ret;
+	unsigned failed_bio_pages = get_bio_pages(failed_bio);
 
 	BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
 
@@ -2382,13 +2394,13 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
 	if (ret)
 		return ret;
 
-	if (!btrfs_check_repairable(inode, failed_bio, failrec,
+	if (!btrfs_check_repairable(inode, failed_bio_pages, failrec,
 				    failed_mirror)) {
 		free_io_failure(failure_tree, tree, failrec);
 		return -EIO;
 	}
 
-	if (failed_bio->bi_vcnt > 1)
+	if (failed_bio_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 4f030912f3ef..300ee10f39f2 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -539,7 +539,7 @@ void btrfs_free_io_failure_record(struct btrfs_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);
-bool btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
+bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_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,
-- 
2.9.4

[PATCH v3 12/49] btrfs: avoid to access bvec table directly for a cloned bio

[Ming Lei]

Commit 17347cec15f919901c90(Btrfs: change how we iterate bios in endio)
mentioned that for dio the submitted bio may be fast cloned, we
can't access the bvec table directly for a cloned bio, so use
bio_get_first_bvec() to retrieve the 1st bvec.

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Cc: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Acked: David Sterba <dsterba@suse.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 fs/btrfs/inode.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 95c212037095..5cf320ee7ea0 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7993,6 +7993,7 @@ static int dio_read_error(struct inode *inode, struct bio *failed_bio,
 	int read_mode = 0;
 	int segs;
 	int ret;
+	struct bio_vec bvec;
 
 	BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
 
@@ -8008,8 +8009,9 @@ static int dio_read_error(struct inode *inode, struct bio *failed_bio,
 	}
 
 	segs = bio_segments(failed_bio);
+	bio_get_first_bvec(failed_bio, &bvec);
 	if (segs > 1 ||
-	    (failed_bio->bi_io_vec->bv_len > btrfs_inode_sectorsize(inode)))
+	    (bvec.bv_len > btrfs_inode_sectorsize(inode)))
 		read_mode |= REQ_FAILFAST_DEV;
 
 	isector = start - btrfs_io_bio(failed_bio)->logical;
-- 
2.9.4

[PATCH v3 13/49] btrfs: comment on direct access bvec table

[Ming Lei]

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Acked: David Sterba <dsterba@suse.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 fs/btrfs/compression.c |  4 ++++
 fs/btrfs/inode.c       | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index d2ef9ac2a630..f795d0a6d176 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -542,6 +542,10 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 
 	/* we need the actual starting offset of this extent in the file */
 	read_lock(&em_tree->lock);
+	/*
+	 * It is still safe to retrieve the 1st page of the bio
+	 * in this way after supporting multipage bvec.
+	 */
 	em = lookup_extent_mapping(em_tree,
 				   page_offset(bio->bi_io_vec->bv_page),
 				   PAGE_SIZE);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5cf320ee7ea0..084ed99dd308 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8051,6 +8051,12 @@ static void btrfs_retry_endio_nocsum(struct bio *bio)
 	if (bio->bi_status)
 		goto end;
 
+	/*
+	 * WARNING:
+	 *
+	 * With multipage bvec, the following way of direct access to
+	 * bvec table is only safe if the bio includes single page.
+	 */
 	ASSERT(bio->bi_vcnt == 1);
 	io_tree = &BTRFS_I(inode)->io_tree;
 	failure_tree = &BTRFS_I(inode)->io_failure_tree;
@@ -8143,6 +8149,12 @@ static void btrfs_retry_endio(struct bio *bio)
 
 	uptodate = 1;
 
+	/*
+	 * WARNING:
+	 *
+	 * With multipage bvec, the following way of direct access to
+	 * bvec table is only safe if the bio includes single page.
+	 */
 	ASSERT(bio->bi_vcnt == 1);
 	ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(done->inode));
 
-- 
2.9.4

[PATCH v3 30/49] btrfs: use bvec_get_last_page to get bio's last page

[Ming Lei]

Preparing for supporting multipage bvec.

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 fs/btrfs/compression.c | 5 ++++-
 fs/btrfs/extent_io.c   | 8 ++++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index f795d0a6d176..28746588f228 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -392,8 +392,11 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 static u64 bio_end_offset(struct bio *bio)
 {
 	struct bio_vec *last = &bio->bi_io_vec[bio->bi_vcnt - 1];
+	struct bio_vec bv;
 
-	return page_offset(last->bv_page) + last->bv_len + last->bv_offset;
+	bvec_get_last_page(last, &bv);
+
+	return page_offset(bv.bv_page) + bv.bv_len + bv.bv_offset;
 }
 
 static noinline int add_ra_bio_pages(struct inode *inode,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 0e7367817b92..c8f6a8657bf2 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2738,11 +2738,15 @@ static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
 {
 	blk_status_t ret = 0;
 	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
-	struct page *page = bvec->bv_page;
 	struct extent_io_tree *tree = bio->bi_private;
+	struct bio_vec bv;
+	struct page *page;
 	u64 start;
 
-	start = page_offset(page) + bvec->bv_offset;
+	bvec_get_last_page(bvec, &bv);
+	page = bv.bv_page;
+
+	start = page_offset(page) + bv.bv_offset;
 
 	bio->bi_private = NULL;
 	bio_get(bio);
-- 
2.9.4

[PATCH v3 46/49] fs/btrfs: convert to bio_for_each_segment_all_sp()

[Ming Lei]

Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 fs/btrfs/compression.c |  3 ++-
 fs/btrfs/disk-io.c     |  3 ++-
 fs/btrfs/extent_io.c   | 12 ++++++++----
 fs/btrfs/inode.c       |  6 ++++--
 fs/btrfs/raid56.c      |  1 +
 5 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 28746588f228..55f251a83d0b 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -147,13 +147,14 @@ static void end_compressed_bio_read(struct bio *bio)
 	} else {
 		int i;
 		struct bio_vec *bvec;
+		struct bvec_iter_all bia;
 
 		/*
 		 * we have verified the checksum already, set page
 		 * checked so the end_io handlers know about it
 		 */
 		ASSERT(!bio_flagged(bio, BIO_CLONED));
-		bio_for_each_segment_all(bvec, cb->orig_bio, i)
+		bio_for_each_segment_all_sp(bvec, cb->orig_bio, i, bia)
 			SetPageChecked(bvec->bv_page);
 
 		bio_endio(cb->orig_bio);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 080e2ebb8aa0..a9cd75e6383d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -963,9 +963,10 @@ static blk_status_t btree_csum_one_bio(struct bio *bio)
 	struct bio_vec *bvec;
 	struct btrfs_root *root;
 	int i, ret = 0;
+	struct bvec_iter_all bia;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all_sp(bvec, bio, i, bia) {
 		root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 		ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
 		if (ret)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index c8f6a8657bf2..4de9cfd1c385 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2359,8 +2359,9 @@ static unsigned int get_bio_pages(struct bio *bio)
 {
 	unsigned i;
 	struct bio_vec *bv;
+	struct bvec_iter_all bia;
 
-	bio_for_each_segment_all(bv, bio, i)
+	bio_for_each_segment_all_sp(bv, bio, i, bia)
 		;
 
 	return i;
@@ -2463,9 +2464,10 @@ static void end_bio_extent_writepage(struct bio *bio)
 	u64 start;
 	u64 end;
 	int i;
+	struct bvec_iter_all bia;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all_sp(bvec, bio, i, bia) {
 		struct page *page = bvec->bv_page;
 		struct inode *inode = page->mapping->host;
 		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -2534,9 +2536,10 @@ static void end_bio_extent_readpage(struct bio *bio)
 	int mirror;
 	int ret;
 	int i;
+	struct bvec_iter_all bia;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all_sp(bvec, bio, i, bia) {
 		struct page *page = bvec->bv_page;
 		struct inode *inode = page->mapping->host;
 		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -3693,9 +3696,10 @@ static void end_bio_extent_buffer_writepage(struct bio *bio)
 	struct bio_vec *bvec;
 	struct extent_buffer *eb;
 	int i, done;
+	struct bvec_iter_all bia;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all_sp(bvec, bio, i, bia) {
 		struct page *page = bvec->bv_page;
 
 		eb = (struct extent_buffer *)page->private;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 084ed99dd308..eeb2ff662ec4 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8047,6 +8047,7 @@ static void btrfs_retry_endio_nocsum(struct bio *bio)
 	struct bio_vec *bvec;
 	struct extent_io_tree *io_tree, *failure_tree;
 	int i;
+	struct bvec_iter_all bia;
 
 	if (bio->bi_status)
 		goto end;
@@ -8064,7 +8065,7 @@ static void btrfs_retry_endio_nocsum(struct bio *bio)
 
 	done->uptodate = 1;
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i)
+	bio_for_each_segment_all_sp(bvec, bio, i, bia)
 		clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
 				 io_tree, done->start, bvec->bv_page,
 				 btrfs_ino(BTRFS_I(inode)), 0);
@@ -8143,6 +8144,7 @@ static void btrfs_retry_endio(struct bio *bio)
 	int uptodate;
 	int ret;
 	int i;
+	struct bvec_iter_all bia;
 
 	if (bio->bi_status)
 		goto end;
@@ -8162,7 +8164,7 @@ static void btrfs_retry_endio(struct bio *bio)
 	failure_tree = &BTRFS_I(inode)->io_failure_tree;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
-	bio_for_each_segment_all(bvec, bio, i) {
+	bio_for_each_segment_all_sp(bvec, bio, i, bia) {
 		ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
 					     bvec->bv_offset, done->start,
 					     bvec->bv_len);
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 208638384cd2..9247226a2efd 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1365,6 +1365,7 @@ static int find_logical_bio_stripe(struct btrfs_raid_bio *rbio,
 	u64 logical = bio->bi_iter.bi_sector;
 	u64 stripe_start;
 	int i;
+	struct bvec_iter_all bia;
 
 	logical <<= 9;
 
-- 
2.9.4

Re: [PATCH v3 46/49] fs/btrfs: convert to bio_for_each_segment_all_sp()

[Filipe Manana]

On Tue, Aug 8, 2017 at 9:45 AM, Ming Lei <ming.lei@redhat.com> wrote:
> Cc: Chris Mason <clm@fb.com>
> Cc: Josef Bacik <jbacik@fb.com>
> Cc: David Sterba <dsterba@suse.com>
> Cc: linux-btrfs@vger.kernel.org
> Signed-off-by: Ming Lei <ming.lei@redhat.com>

Can you please add some meaningful changelog? E.g., why is this
conversion needed.

> ---
>  fs/btrfs/compression.c |  3 ++-
>  fs/btrfs/disk-io.c     |  3 ++-
>  fs/btrfs/extent_io.c   | 12 ++++++++----
>  fs/btrfs/inode.c       |  6 ++++--
>  fs/btrfs/raid56.c      |  1 +
>  5 files changed, 17 insertions(+), 8 deletions(-)
>
> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
> index 28746588f228..55f251a83d0b 100644
> --- a/fs/btrfs/compression.c
> +++ b/fs/btrfs/compression.c
> @@ -147,13 +147,14 @@ static void end_compressed_bio_read(struct bio *bio)
>         } else {
>                 int i;
>                 struct bio_vec *bvec;
> +               struct bvec_iter_all bia;
>
>                 /*
>                  * we have verified the checksum already, set page
>                  * checked so the end_io handlers know about it
>                  */
>                 ASSERT(!bio_flagged(bio, BIO_CLONED));
> -               bio_for_each_segment_all(bvec, cb->orig_bio, i)
> +               bio_for_each_segment_all_sp(bvec, cb->orig_bio, i, bia)
>                         SetPageChecked(bvec->bv_page);
>
>                 bio_endio(cb->orig_bio);
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 080e2ebb8aa0..a9cd75e6383d 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -963,9 +963,10 @@ static blk_status_t btree_csum_one_bio(struct bio *bio)
>         struct bio_vec *bvec;
>         struct btrfs_root *root;
>         int i, ret = 0;
> +       struct bvec_iter_all bia;
>
>         ASSERT(!bio_flagged(bio, BIO_CLONED));
> -       bio_for_each_segment_all(bvec, bio, i) {
> +       bio_for_each_segment_all_sp(bvec, bio, i, bia) {
>                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
>                 ret = csum_dirty_buffer(root->fs_info, bvec->bv_page);
>                 if (ret)
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index c8f6a8657bf2..4de9cfd1c385 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -2359,8 +2359,9 @@ static unsigned int get_bio_pages(struct bio *bio)
>  {
>         unsigned i;
>         struct bio_vec *bv;
> +       struct bvec_iter_all bia;
>
> -       bio_for_each_segment_all(bv, bio, i)
> +       bio_for_each_segment_all_sp(bv, bio, i, bia)
>                 ;
>
>         return i;
> @@ -2463,9 +2464,10 @@ static void end_bio_extent_writepage(struct bio *bio)
>         u64 start;
>         u64 end;
>         int i;
> +       struct bvec_iter_all bia;
>
>         ASSERT(!bio_flagged(bio, BIO_CLONED));
> -       bio_for_each_segment_all(bvec, bio, i) {
> +       bio_for_each_segment_all_sp(bvec, bio, i, bia) {
>                 struct page *page = bvec->bv_page;
>                 struct inode *inode = page->mapping->host;
>                 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> @@ -2534,9 +2536,10 @@ static void end_bio_extent_readpage(struct bio *bio)
>         int mirror;
>         int ret;
>         int i;
> +       struct bvec_iter_all bia;
>
>         ASSERT(!bio_flagged(bio, BIO_CLONED));
> -       bio_for_each_segment_all(bvec, bio, i) {
> +       bio_for_each_segment_all_sp(bvec, bio, i, bia) {
>                 struct page *page = bvec->bv_page;
>                 struct inode *inode = page->mapping->host;
>                 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> @@ -3693,9 +3696,10 @@ static void end_bio_extent_buffer_writepage(struct bio *bio)
>         struct bio_vec *bvec;
>         struct extent_buffer *eb;
>         int i, done;
> +       struct bvec_iter_all bia;
>
>         ASSERT(!bio_flagged(bio, BIO_CLONED));
> -       bio_for_each_segment_all(bvec, bio, i) {
> +       bio_for_each_segment_all_sp(bvec, bio, i, bia) {
>                 struct page *page = bvec->bv_page;
>
>                 eb = (struct extent_buffer *)page->private;
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 084ed99dd308..eeb2ff662ec4 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -8047,6 +8047,7 @@ static void btrfs_retry_endio_nocsum(struct bio *bio)
>         struct bio_vec *bvec;
>         struct extent_io_tree *io_tree, *failure_tree;
>         int i;
> +       struct bvec_iter_all bia;
>
>         if (bio->bi_status)
>                 goto end;
> @@ -8064,7 +8065,7 @@ static void btrfs_retry_endio_nocsum(struct bio *bio)
>
>         done->uptodate = 1;
>         ASSERT(!bio_flagged(bio, BIO_CLONED));
> -       bio_for_each_segment_all(bvec, bio, i)
> +       bio_for_each_segment_all_sp(bvec, bio, i, bia)
>                 clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
>                                  io_tree, done->start, bvec->bv_page,
>                                  btrfs_ino(BTRFS_I(inode)), 0);
> @@ -8143,6 +8144,7 @@ static void btrfs_retry_endio(struct bio *bio)
>         int uptodate;
>         int ret;
>         int i;
> +       struct bvec_iter_all bia;
>
>         if (bio->bi_status)
>                 goto end;
> @@ -8162,7 +8164,7 @@ static void btrfs_retry_endio(struct bio *bio)
>         failure_tree = &BTRFS_I(inode)->io_failure_tree;
>
>         ASSERT(!bio_flagged(bio, BIO_CLONED));
> -       bio_for_each_segment_all(bvec, bio, i) {
> +       bio_for_each_segment_all_sp(bvec, bio, i, bia) {
>                 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
>                                              bvec->bv_offset, done->start,
>                                              bvec->bv_len);
> diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
> index 208638384cd2..9247226a2efd 100644
> --- a/fs/btrfs/raid56.c
> +++ b/fs/btrfs/raid56.c
> @@ -1365,6 +1365,7 @@ static int find_logical_bio_stripe(struct btrfs_raid_bio *rbio,
>         u64 logical = bio->bi_iter.bi_sector;
>         u64 stripe_start;
>         int i;
> +       struct bvec_iter_all bia;

Unused variable.

Thanks.

>
>         logical <<= 9;
>
> --
> 2.9.4
>



-- 
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”

Re: [PATCH v3 11/49] btrfs: avoid access to .bi_vcnt directly

[Christoph Hellwig]

> +static unsigned int get_bio_pages(struct bio *bio)
> +{
> +	unsigned i;
> +	struct bio_vec *bv;
> +
> +	bio_for_each_segment_all(bv, bio, i)
> +		;
> +
> +	return i;
> +}

s/get_bio_pages/bio_nr_pages/ ?

Also this seems like a useful helper for bio.h

Re: [PATCH v3 46/49] fs/btrfs: convert to bio_for_each_segment_all_sp()

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 1619 bytes --]

Hi Ming,

[auto build test WARNING on linus/master]
[also build test WARNING on v4.13-rc4 next-20170810]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Ming-Lei/block-support-multipage-bvec/20170810-110521
config: x86_64-randconfig-b0-08112217 (attached as .config)
compiler: gcc-4.4 (Debian 4.4.7-8) 4.4.7
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   fs/btrfs/raid56.c: In function 'find_logical_bio_stripe':
>> fs/btrfs/raid56.c:1368: warning: unused variable 'bia'

vim +/bia +1368 fs/btrfs/raid56.c

  1356	
  1357	/*
  1358	 * helper to find the stripe number for a given
  1359	 * bio (before mapping).  Used to figure out which stripe has
  1360	 * failed.  This looks up based on logical block numbers.
  1361	 */
  1362	static int find_logical_bio_stripe(struct btrfs_raid_bio *rbio,
  1363					   struct bio *bio)
  1364	{
  1365		u64 logical = bio->bi_iter.bi_sector;
  1366		u64 stripe_start;
  1367		int i;
> 1368		struct bvec_iter_all bia;
  1369	
  1370		logical <<= 9;
  1371	
  1372		for (i = 0; i < rbio->nr_data; i++) {
  1373			stripe_start = rbio->bbio->raid_map[i];
  1374			if (logical >= stripe_start &&
  1375			    logical < stripe_start + rbio->stripe_len) {
  1376				return i;
  1377			}
  1378		}
  1379		return -1;
  1380	}
  1381	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 28376 bytes --]

Re: [PATCH v3 11/49] btrfs: avoid access to .bi_vcnt directly

[Ming Lei]

On Thu, Aug 10, 2017 at 04:29:59AM -0700, Christoph Hellwig wrote:
> > +static unsigned int get_bio_pages(struct bio *bio)
> > +{
> > +	unsigned i;
> > +	struct bio_vec *bv;
> > +
> > +	bio_for_each_segment_all(bv, bio, i)
> > +		;
> > +
> > +	return i;
> > +}
> 
> s/get_bio_pages/bio_nr_pages/ ?

Yeah, the name of bio_nr_pages() is much better.

> 
> Also this seems like a useful helper for bio.h

OK.


-- 
Ming