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authorKaran Tilak Kumar <kartilak@cisco.com>2023-08-17 21:21:46 +0300
committerMartin K. Petersen <martin.petersen@oracle.com>2023-08-26 00:15:09 +0300
commit15924b0503630016dee4dbb945a8df4df659070b (patch)
treea23dcbed97bfb274091c5d1cbabacbd5825504e0 /drivers/scsi/fnic
parent530e86c745ae3342b1df5e8f38529b9f8a6cac17 (diff)
downloadlinux-15924b0503630016dee4dbb945a8df4df659070b.tar.xz
scsi: fnic: Replace sgreset tag with max_tag_id
sgreset is issued with a SCSI command pointer. The device reset code assumes that it was issued on a hardware queue, and calls block multiqueue layer. However, the assumption is broken, and there is no hardware queue associated with the sgreset, and this leads to a crash due to a null pointer exception. Fix the code to use the max_tag_id as a tag which does not overlap with the other tags issued by mid layer. Tested by running FC traffic for a few minutes, and by issuing sgreset on the device in parallel. Without the fix, the crash is observed right away. With this fix, no crash is observed. Reviewed-by: Sesidhar Baddela <sebaddel@cisco.com> Tested-by: Karan Tilak Kumar <kartilak@cisco.com> Signed-off-by: Karan Tilak Kumar <kartilak@cisco.com> Link: https://lore.kernel.org/r/20230817182146.229059-1-kartilak@cisco.com Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/fnic')
-rw-r--r--drivers/scsi/fnic/fnic.h3
-rw-r--r--drivers/scsi/fnic/fnic_scsi.c20
2 files changed, 11 insertions, 12 deletions
diff --git a/drivers/scsi/fnic/fnic.h b/drivers/scsi/fnic/fnic.h
index d82de34f6fd7..93c68931a593 100644
--- a/drivers/scsi/fnic/fnic.h
+++ b/drivers/scsi/fnic/fnic.h
@@ -27,7 +27,7 @@
#define DRV_NAME "fnic"
#define DRV_DESCRIPTION "Cisco FCoE HBA Driver"
-#define DRV_VERSION "1.6.0.54"
+#define DRV_VERSION "1.6.0.56"
#define PFX DRV_NAME ": "
#define DFX DRV_NAME "%d: "
@@ -236,6 +236,7 @@ struct fnic {
unsigned int wq_count;
unsigned int cq_count;
+ struct mutex sgreset_mutex;
struct dentry *fnic_stats_debugfs_host;
struct dentry *fnic_stats_debugfs_file;
struct dentry *fnic_reset_debugfs_file;
diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c
index 26dbd347156e..8ce3e3c3a882 100644
--- a/drivers/scsi/fnic/fnic_scsi.c
+++ b/drivers/scsi/fnic/fnic_scsi.c
@@ -2220,7 +2220,6 @@ int fnic_device_reset(struct scsi_cmnd *sc)
struct reset_stats *reset_stats;
int tag = rq->tag;
DECLARE_COMPLETION_ONSTACK(tm_done);
- int tag_gen_flag = 0; /*to track tags allocated by fnic driver*/
bool new_sc = 0;
/* Wait for rport to unblock */
@@ -2250,17 +2249,17 @@ int fnic_device_reset(struct scsi_cmnd *sc)
}
fnic_priv(sc)->flags = FNIC_DEVICE_RESET;
- /* Allocate tag if not present */
if (unlikely(tag < 0)) {
/*
- * Really should fix the midlayer to pass in a proper
- * request for ioctls...
+ * For device reset issued through sg3utils, we let
+ * only one LUN_RESET to go through and use a special
+ * tag equal to max_tag_id so that we don't have to allocate
+ * or free it. It won't interact with tags
+ * allocated by mid layer.
*/
- tag = fnic_scsi_host_start_tag(fnic, sc);
- if (unlikely(tag == SCSI_NO_TAG))
- goto fnic_device_reset_end;
- tag_gen_flag = 1;
+ mutex_lock(&fnic->sgreset_mutex);
+ tag = fnic->fnic_max_tag_id;
new_sc = 1;
}
io_lock = fnic_io_lock_hash(fnic, sc);
@@ -2432,9 +2431,8 @@ fnic_device_reset_end:
(u64)sc->cmnd[4] << 8 | sc->cmnd[5]),
fnic_flags_and_state(sc));
- /* free tag if it is allocated */
- if (unlikely(tag_gen_flag))
- fnic_scsi_host_end_tag(fnic, sc);
+ if (new_sc)
+ mutex_unlock(&fnic->sgreset_mutex);
FNIC_SCSI_DBG(KERN_DEBUG, fnic->lport->host,
"Returning from device reset %s\n",