When sd_revalidate() is executed for a ZBC disk (zoned block device),
sd_zbc_read_zones() is called to revalidate the disk zone configuration.
This executes sd_zbc_check_zone_size() to check that the disk zone sizes
are in line with the defined constraints (all zones must be the same
size and a power of 2 number of LBAs). As part of its execution,
sd_zbc_check_zone_size() was temporarily setting sdkp->zone_blocks to 0.
If during the execution of sd_zbc_check_zone_size() within
sd_revalidate() context, another context issues a command which
references sdkp->zone_blocks to check zone alignment of the command
(e.g. a zone reset is issued and sd_zbc_setup_reset_cmnd() is called),
an invalid value for the disk zone size is used and the alignment check
fails.
Simply fix this by using an on-stack variable inside
sd_zbc_check_zone_size() instead of directly using sdkp->zone_blocks.
This change is valid for both revalidate as well as for the first scan
of the device.
Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
drivers/scsi/sd_zbc.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index 89cf4498f535..b59454ed5087 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -403,6 +403,7 @@ static int sd_zbc_check_capacity(struct scsi_disk *sdkp, unsigned char *buf)
*/
static int sd_zbc_check_zone_size(struct scsi_disk *sdkp)
{
+ u64 sdkp_zone_blocks = sdkp->zone_blocks;
u64 zone_blocks = 0;
sector_t block = 0;
unsigned char *buf;
@@ -412,8 +413,6 @@ static int sd_zbc_check_zone_size(struct scsi_disk *sdkp)
int ret;
u8 same;
- sdkp->zone_blocks = 0;
-
/* Get a buffer */
buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL);
if (!buf)
@@ -446,11 +445,11 @@ static int sd_zbc_check_zone_size(struct scsi_disk *sdkp)
/* Parse zone descriptors */
while (rec < buf + buf_len) {
zone_blocks = get_unaligned_be64(&rec[8]);
- if (sdkp->zone_blocks == 0) {
- sdkp->zone_blocks = zone_blocks;
- } else if (zone_blocks != sdkp->zone_blocks &&
+ if (sdkp_zone_blocks == 0) {
+ sdkp_zone_blocks = zone_blocks;
+ } else if (zone_blocks != sdkp_zone_blocks &&
(block + zone_blocks < sdkp->capacity
- || zone_blocks > sdkp->zone_blocks)) {
+ || zone_blocks > sdkp_zone_blocks)) {
zone_blocks = 0;
goto out;
}
@@ -467,7 +466,7 @@ static int sd_zbc_check_zone_size(struct scsi_disk *sdkp)
} while (block < sdkp->capacity);
- zone_blocks = sdkp->zone_blocks;
+ zone_blocks = sdkp_zone_blocks;
out:
if (!zone_blocks) {
--
2.14.3
