seqnum_ops api is introduced to be used when a variable is used as
a sequence/stat counter and doesn't guard object lifetimes. This
clearly differentiates atomic_t usages that guard object lifetimes.
seqnum32 variables wrap around to INT_MIN when it overflows and
should not be used to guard resource lifetimes, device usage and
open counts that control state changes, and pm states.
atomic_t variables used for error_count and ios_threshold are atomic
counters and guarded by max. values. No change to the behavior with
this change.
Signed-off-by: Shuah Khan <sk...@linuxfoundation.org>
---
.../staging/unisys/visorhba/visorhba_main.c | 37 ++++++++++---------
1 file changed, 19 insertions(+), 18 deletions(-)
diff --git a/drivers/staging/unisys/visorhba/visorhba_main.c
b/drivers/staging/unisys/visorhba/visorhba_main.c
index 7ae5306b92fe..3209958b8aaa 100644
--- a/drivers/staging/unisys/visorhba/visorhba_main.c
+++ b/drivers/staging/unisys/visorhba/visorhba_main.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/visorbus.h>
+#include <linux/seqnum_ops.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
@@ -41,8 +42,8 @@ MODULE_ALIAS("visorbus:" VISOR_VHBA_CHANNEL_GUID_STR);
struct visordisk_info {
struct scsi_device *sdev;
u32 valid;
- atomic_t ios_threshold;
- atomic_t error_count;
+ struct seqnum32 ios_threshold;
+ struct seqnum32 error_count;
struct visordisk_info *next;
};
@@ -374,10 +375,10 @@ static int visorhba_abort_handler(struct scsi_cmnd
*scsicmd)
scsidev = scsicmd->device;
vdisk = scsidev->hostdata;
- if (atomic_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT)
- atomic_inc(&vdisk->error_count);
+ if (seqnum32_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT)
+ seqnum32_inc(&vdisk->error_count);
else
- atomic_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
+ seqnum32_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
rtn = forward_taskmgmt_command(TASK_MGMT_ABORT_TASK, scsidev);
if (rtn == SUCCESS) {
scsicmd->result = DID_ABORT << 16;
@@ -401,10 +402,10 @@ static int visorhba_device_reset_handler(struct scsi_cmnd
*scsicmd)
scsidev = scsicmd->device;
vdisk = scsidev->hostdata;
- if (atomic_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT)
- atomic_inc(&vdisk->error_count);
+ if (seqnum32_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT)
+ seqnum32_inc(&vdisk->error_count);
else
- atomic_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
+ seqnum32_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
rtn = forward_taskmgmt_command(TASK_MGMT_LUN_RESET, scsidev);
if (rtn == SUCCESS) {
scsicmd->result = DID_RESET << 16;
@@ -429,10 +430,10 @@ static int visorhba_bus_reset_handler(struct scsi_cmnd
*scsicmd)
scsidev = scsicmd->device;
shost_for_each_device(scsidev, scsidev->host) {
vdisk = scsidev->hostdata;
- if (atomic_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT)
- atomic_inc(&vdisk->error_count);
+ if (seqnum32_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT)
+ seqnum32_inc(&vdisk->error_count);
else
- atomic_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
+ seqnum32_set(&vdisk->ios_threshold,
IOS_ERROR_THRESHOLD);
}
rtn = forward_taskmgmt_command(TASK_MGMT_BUS_RESET, scsidev);
if (rtn == SUCCESS) {
@@ -803,9 +804,9 @@ static void do_scsi_linuxstat(struct uiscmdrsp *cmdrsp,
return;
/* Okay see what our error_count is here.... */
vdisk = scsidev->hostdata;
- if (atomic_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT) {
- atomic_inc(&vdisk->error_count);
- atomic_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
+ if (seqnum32_read(&vdisk->error_count) < VISORHBA_ERROR_COUNT) {
+ seqnum32_inc(&vdisk->error_count);
+ seqnum32_set(&vdisk->ios_threshold, IOS_ERROR_THRESHOLD);
}
}
@@ -881,10 +882,10 @@ static void do_scsi_nolinuxstat(struct uiscmdrsp *cmdrsp,
kfree(buf);
} else {
vdisk = scsidev->hostdata;
- if (atomic_read(&vdisk->ios_threshold) > 0) {
- atomic_dec(&vdisk->ios_threshold);
- if (atomic_read(&vdisk->ios_threshold) == 0)
- atomic_set(&vdisk->error_count, 0);
+ if (seqnum32_read(&vdisk->ios_threshold) > 0) {
+ seqnum32_dec(&vdisk->ios_threshold);
+ if (seqnum32_read(&vdisk->ios_threshold) == 0)
+ seqnum32_set(&vdisk->error_count, 0);
}
}
}
--
2.27.0
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