dm-io: clone the source bio instead of copying its biovec

drivers/md/dm-io.c

@@ -37,6 +37,7 @@ struct io {
 	struct dm_io_client *client;
 	io_notify_fn callback;
 	void *context;
+	struct bio *orig_bio;
 	void *vma_invalidate_address;
 	unsigned long vma_invalidate_size;
 } __aligned(DM_IO_MAX_REGIONS);
@@ -132,8 +133,18 @@ static void complete_io(struct io *io)
 
 static void dec_count(struct io *io, unsigned int region, blk_status_t error)
 {
-	if (error)
+	if (error) {
 		set_bit(region, &io->error_bits);
+		/*
+		 * BLK_STS_INVAL means the bio was not valid for the underlying
+		 * device (e.g. a misaligned direct I/O), which is a caller error
+		 * rather than a device failure. Record it on the original bio so
+		 * bio-based targets can propagate it instead of treating it as a
+		 * media error and failing the device.
+		 */
+		if (error == BLK_STS_INVAL && io->orig_bio)
+			io->orig_bio->bi_status = error;
+	}
 
 	if (atomic_dec_and_test(&io->count))
 		complete_io(io);
@@ -170,12 +181,11 @@ struct dpages {
 			 struct page **p, unsigned long *len, unsigned int *offset);
 	void (*next_page)(struct dpages *dp);
 
-	union {
-		unsigned int context_u;
-		struct bvec_iter context_bi;
-	};
+	unsigned int context_u;
 	void *context_ptr;
 
+	struct bio *orig_bio;
+
 	void *vma_invalidate_address;
 	unsigned long vma_invalidate_size;
 };
@@ -210,44 +220,6 @@ static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned int o
 	dp->context_ptr = pl;
 }
 
-/*
- * Functions for getting the pages from a bvec.
- */
-static void bio_get_page(struct dpages *dp, struct page **p,
-			 unsigned long *len, unsigned int *offset)
-{
-	struct bio_vec bvec = bvec_iter_bvec((struct bio_vec *)dp->context_ptr,
-					     dp->context_bi);
-
-	*p = bvec.bv_page;
-	*len = bvec.bv_len;
-	*offset = bvec.bv_offset;
-
-	/* avoid figuring it out again in bio_next_page() */
-	dp->context_bi.bi_sector = (sector_t)bvec.bv_len;
-}
-
-static void bio_next_page(struct dpages *dp)
-{
-	unsigned int len = (unsigned int)dp->context_bi.bi_sector;
-
-	bvec_iter_advance((struct bio_vec *)dp->context_ptr,
-			  &dp->context_bi, len);
-}
-
-static void bio_dp_init(struct dpages *dp, struct bio *bio)
-{
-	dp->get_page = bio_get_page;
-	dp->next_page = bio_next_page;
-
-	/*
-	 * We just use bvec iterator to retrieve pages, so it is ok to
-	 * access the bvec table directly here
-	 */
-	dp->context_ptr = bio->bi_io_vec;
-	dp->context_bi = bio->bi_iter;
-}
-
 /*
  * Functions for getting the pages from a VMA.
  */
@@ -332,6 +304,21 @@ static void do_region(const blk_opf_t opf, unsigned int region,
 		return;
 	}
 
+	if (dp->orig_bio) {
+		bio = bio_alloc_clone(where->bdev, dp->orig_bio, GFP_NOIO,
+				      &io->client->bios);
+		bio->bi_iter.bi_sector = where->sector;
+		bio->bi_iter.bi_size = where->count << SECTOR_SHIFT;
+		bio->bi_opf = opf;
+		bio->bi_end_io = endio;
+		bio->bi_ioprio = ioprio;
+		store_io_and_region_in_bio(bio, io, region);
+
+		atomic_inc(&io->count);
+		submit_bio(bio);
+		return;
+	}
+
 	/*
 	 * where->count may be zero if op holds a flush and we need to
 	 * send a zero-sized flush.
@@ -422,6 +409,7 @@ static void async_io(struct dm_io_client *client, unsigned int num_regions,
 	io->client = client;
 	io->callback = fn;
 	io->context = context;
+	io->orig_bio = dp->orig_bio;
 
 	io->vma_invalidate_address = dp->vma_invalidate_address;
 	io->vma_invalidate_size = dp->vma_invalidate_size;
@@ -468,14 +456,19 @@ static int dp_init(struct dm_io_request *io_req, struct dpages *dp,
 
 	dp->vma_invalidate_address = NULL;
 	dp->vma_invalidate_size = 0;
+	dp->orig_bio = NULL;
 
 	switch (io_req->mem.type) {
 	case DM_IO_PAGE_LIST:
 		list_dp_init(dp, io_req->mem.ptr.pl, io_req->mem.offset);
 		break;
 
 	case DM_IO_BIO:
-		bio_dp_init(dp, io_req->mem.ptr.bio);
+		/*
+		 * The destination bios clone this bio's biovec directly, so
+		 * there are no per-page accessors to set up here.
+		 */
+		dp->orig_bio = io_req->mem.ptr.bio;
 		break;
 
 	case DM_IO_VMA:

drivers/md/dm-raid1.c

@@ -524,6 +524,17 @@ static void read_callback(unsigned long error, void *context)
 		return;
 	}
 
+	/*
+	 * BLK_STS_INVAL means the bio was not valid for the underlying device,
+	 * e.g. a misaligned direct I/O. That is a caller error, not a device
+	 * failure, so propagate it rather than failing the mirror and retrying
+	 * on the other legs, which would fail the same way.
+	 */
+	if (bio->bi_status == BLK_STS_INVAL) {
+		bio_endio(bio);
+		return;
+	}
+
 	fail_mirror(m, DM_RAID1_READ_ERROR);
 
 	if (likely(default_ok(m)) || mirror_available(m->ms, bio)) {
@@ -622,6 +633,16 @@ static void write_callback(unsigned long error, void *context)
 		return;
 	}
 
+	/*
+	 * BLK_STS_INVAL means the bio was not valid for the underlying device,
+	 * e.g. a misaligned direct I/O. Propagate the error without degrading
+	 * the array.
+	 */
+	if (bio->bi_status == BLK_STS_INVAL) {
+		bio_endio(bio);
+		return;
+	}
+
 	/*
 	 * If the bio is discard, return an error, but do not
 	 * degrade the array.
@@ -1262,7 +1283,12 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
 		return DM_ENDIO_DONE;
 	}
 
-	if (*error == BLK_STS_NOTSUPP)
+	/*
+	 * BLK_STS_INVAL means the bio was not valid for the underlying device,
+	 * e.g. a misaligned direct I/O. Propagate it rather than failing the
+	 * mirror and retrying, which would fail the same way on every leg.
+	 */
+	if (*error == BLK_STS_NOTSUPP || *error == BLK_STS_INVAL)
 		goto out;
 
 	if (bio->bi_opf & REQ_RAHEAD)