From: Keith Busch <kbusch@xxxxxxxxxx>
We're already iterating every segment, so check these for a valid IO at
the same time.
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
---
block/blk-map.c | 2 +-
block/blk-merge.c | 20 ++++++++++++++++----
include/linux/bio.h | 4 ++--
include/linux/blkdev.h | 13 +++++++++++++
4 files changed, 32 insertions(+), 7 deletions(-)
diff --git a/block/blk-map.c b/block/blk-map.c
index 23e5d5ebe59ec..c5da9d37deee9 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -443,7 +443,7 @@ int blk_rq_append_bio(struct request *rq, struct bio *bio)
int ret;
/* check that the data layout matches the hardware restrictions */
- ret = bio_split_rw_at(bio, lim, &nr_segs, max_bytes);
+ ret = bio_split_drv_at(bio, lim, &nr_segs, max_bytes);
if (ret) {
/* if we would have to split the bio, copy instead */
if (ret > 0)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 70d704615be52..a0d8364983000 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -279,25 +279,29 @@ static unsigned int bio_split_alignment(struct bio *bio,
}
/**
- * bio_split_rw_at - check if and where to split a read/write bio
+ * bio_split_io_at - check if and where to split a read/write bio
* @bio: [in] bio to be split
* @lim: [in] queue limits to split based on
* @segs: [out] number of segments in the bio with the first half of the sectors
* @max_bytes: [in] maximum number of bytes per bio
+ * @len_align: [in] length alignment for each vector
*
* Find out if @bio needs to be split to fit the queue limits in @lim and a
* maximum size of @max_bytes. Returns a negative error number if @bio can't be
* split, 0 if the bio doesn't have to be split, or a positive sector offset if
* @bio needs to be split.
*/
-int bio_split_rw_at(struct bio *bio, const struct queue_limits *lim,
- unsigned *segs, unsigned max_bytes)
+int bio_split_io_at(struct bio *bio, const struct queue_limits *lim,
+ unsigned *segs, unsigned max_bytes, unsigned len_align)
{
struct bio_vec bv, bvprv, *bvprvp = NULL;
struct bvec_iter iter;
unsigned nsegs = 0, bytes = 0;
bio_for_each_bvec(bv, bio, iter) {
+ if (bv.bv_offset & lim->dma_alignment || bv.bv_len & len_align)
+ return -EINVAL;
+
/*
* If the queue doesn't support SG gaps and adding this
* offset would create a gap, disallow it.
@@ -339,8 +343,16 @@ int bio_split_rw_at(struct bio *bio, const struct queue_limits *lim,
* Individual bvecs might not be logical block aligned. Round down the
* split size so that each bio is properly block size aligned, even if
* we do not use the full hardware limits.
+ *
+ * Misuse may submit a bio that can't be split into a valid io. There
+ * may either be too many discontiguous vectors for the max segments
+ * limit, or contain virtual boundary gaps without having a valid block
+ * sized split. Catch that condition by checking for a zero byte
+ * result.
*/
bytes = ALIGN_DOWN(bytes, bio_split_alignment(bio, lim));
+ if (!bytes)
+ return -EINVAL;
/*
* Bio splitting may cause subtle trouble such as hang when doing sync
@@ -350,7 +362,7 @@ int bio_split_rw_at(struct bio *bio, const struct queue_limits *lim,
bio_clear_polled(bio);
return bytes >> SECTOR_SHIFT;
}
-EXPORT_SYMBOL_GPL(bio_split_rw_at);
+EXPORT_SYMBOL_GPL(bio_split_io_at);
struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
unsigned *nr_segs)
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 46ffac5caab78..519a1d59805f8 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -322,8 +322,8 @@ static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio)
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);
-int bio_split_rw_at(struct bio *bio, const struct queue_limits *lim,
- unsigned *segs, unsigned max_bytes);
+int bio_split_io_at(struct bio *bio, const struct queue_limits *lim,
+ unsigned *segs, unsigned max_bytes, unsigned len_align);
/**
* bio_next_split - get next @sectors from a bio, splitting if necessary
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 95886b404b16b..7f83ad2df5425 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1869,6 +1869,19 @@ bdev_atomic_write_unit_max_bytes(struct block_device *bdev)
return queue_atomic_write_unit_max_bytes(bdev_get_queue(bdev));
}
+static inline int bio_split_rw_at(struct bio *bio,
+ const struct queue_limits *lim,
+ unsigned *segs, unsigned max_bytes)
+{
+ return bio_split_io_at(bio, lim, segs, max_bytes, lim->dma_alignment);
+}
+
+static inline int bio_split_drv_at(struct bio *bio,
+ const struct queue_limits *lim,
+ unsigned *segs, unsigned max_bytes)
+{
+ return bio_split_io_at(bio, lim, segs, max_bytes, 0);
+}
#define DEFINE_IO_COMP_BATCH(name) struct io_comp_batch name = { }
#endif /* _LINUX_BLKDEV_H */
--
2.47.3
