[v3,1/3] block: fix arg type of bio_trim()

Commit Message

Naohiro Aota July 21, 2021, 12:43 p.m. UTC

From: Chaitanya Kulkarni <[e-mail]>

The function bio_trim has offset and size arguments that are declared
as int.

The callers of this function uses sector_t type when passing the offset
and size e,g. drivers/md/raid1.c:narrow_write_error() and
drivers/md/raid1.c:narrow_write_error().

Change offset and size arguments to sector_t type for bio_trim(). Also, add
WARN_ON_ONCE() to catch their overflow.

Signed-off-by: Chaitanya Kulkarni <[e-mail]>
Signed-off-by: Naohiro Aota <[e-mail]>
---
 block/bio.c               | 12 +++++++-----
 include/linux/bio.h       |  2 +-
 include/linux/blk_types.h |  1 +
 3 files changed, 9 insertions(+), 6 deletions(-)

Comments

Christoph Hellwig July 21, 2021, 3:21 p.m. UTC | #1

Looks good,

Reviewed-by: Christoph Hellwig <[e-mail]>

Patch

diff --git a/block/bio.c b/block/bio.c
index 44205dfb6b60..0bf2b865feaf 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1464,12 +1464,15 @@  EXPORT_SYMBOL(bio_split);
  * @bio:	bio to trim
  * @offset:	number of sectors to trim from the front of @bio
  * @size:	size we want to trim @bio to, in sectors
+ *
+ * This function is typically used for bios that are cloned and submitted
+ * to the underlying device in parts.
  */
-void bio_trim(struct bio *bio, int offset, int size)
+void bio_trim(struct bio *bio, sector_t offset, sector_t size)
 {
-	/* 'bio' is a cloned bio which we need to trim to match
-	 * the given offset and size.
-	 */
+	if (WARN_ON_ONCE(offset > BIO_MAX_SECTORS || size > BIO_MAX_SECTORS ||
+			 offset + size > bio->bi_iter.bi_size))
+		return;
 
 	size <<= 9;
 	if (offset == 0 && size == bio->bi_iter.bi_size)
@@ -1480,7 +1483,6 @@  void bio_trim(struct bio *bio, int offset, int size)
 
 	if (bio_integrity(bio))
 		bio_integrity_trim(bio);
-
 }
 EXPORT_SYMBOL_GPL(bio_trim);
 
diff --git a/include/linux/bio.h b/include/linux/bio.h
index a0b4cfdf62a4..fb663152521e 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -379,7 +379,7 @@  static inline void bip_set_seed(struct bio_integrity_payload *bip,
 
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
-extern void bio_trim(struct bio *bio, int offset, int size);
+void bio_trim(struct bio *bio, sector_t offset, sector_t size);
 extern struct bio *bio_split(struct bio *bio, int sectors,
 			     gfp_t gfp, struct bio_set *bs);
 
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index db026b6ec15a..24dfb980fb3f 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -285,6 +285,7 @@  struct bio {
 };
 
 #define BIO_RESET_BYTES		offsetof(struct bio, bi_max_vecs)
+#define BIO_MAX_SECTORS		(UINT_MAX >> SECTOR_SHIFT)
 
 /*
  * bio flags