[GIT PULL] SCSI fixes for 6.15-rc6

From: James Bottomley
Date: Fri May 16 2025 - 11:33:04 EST


Fix to zone block devices to make the maximum segment count match what
the block layer is capable of.

The patch is available here:

git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes

The short changelog is:

Steve Siwinski (1):
scsi: sd_zbc: block: Respect bio vector limits for REPORT ZONES buffer

And the diffstat:

block/bio.c | 2 +-
drivers/scsi/sd_zbc.c | 6 +++++-
include/linux/bio.h | 1 +

With full diff below

James

---

diff --git a/block/bio.c b/block/bio.c
index 4e6c85a33d74..4be592d37fb6 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -611,7 +611,7 @@ struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask)
{
struct bio *bio;

- if (nr_vecs > UIO_MAXIOV)
+ if (nr_vecs > BIO_MAX_INLINE_VECS)
return NULL;
return kmalloc(struct_size(bio, bi_inline_vecs, nr_vecs), gfp_mask);
}
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index 7a447ff600d2..a8db66428f80 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -169,6 +169,7 @@ static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
unsigned int nr_zones, size_t *buflen)
{
struct request_queue *q = sdkp->disk->queue;
+ unsigned int max_segments;
size_t bufsize;
void *buf;

@@ -180,12 +181,15 @@ static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
* Furthermore, since the report zone command cannot be split, make
* sure that the allocated buffer can always be mapped by limiting the
* number of pages allocated to the HBA max segments limit.
+ * Since max segments can be larger than the max inline bio vectors,
+ * further limit the allocated buffer to BIO_MAX_INLINE_VECS.
*/
nr_zones = min(nr_zones, sdkp->zone_info.nr_zones);
bufsize = roundup((nr_zones + 1) * 64, SECTOR_SIZE);
bufsize = min_t(size_t, bufsize,
queue_max_hw_sectors(q) << SECTOR_SHIFT);
- bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
+ max_segments = min(BIO_MAX_INLINE_VECS, queue_max_segments(q));
+ bufsize = min_t(size_t, bufsize, max_segments << PAGE_SHIFT);

while (bufsize >= SECTOR_SIZE) {
buf = kvzalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
diff --git a/include/linux/bio.h b/include/linux/bio.h
index cafc7c215de8..b786ec5bcc81 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -11,6 +11,7 @@
#include <linux/uio.h>

#define BIO_MAX_VECS 256U
+#define BIO_MAX_INLINE_VECS UIO_MAXIOV

struct queue_limits;