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scsi: scsi_debug: Protect block_unblock_all_queues() with mutex

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There is no reason that calls to block_unblock_all_queues() from different
context can't race with one another, so protect with the
sdebug_host_list_mutex. There's no need for a more fine-grained per shost
locking here (and we don't have a per-host lock anyway).

Also simplify some touched code in sdebug_change_qdepth().

Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20230327074310.1862889-5-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
John Garry 2023-03-27 07:43:03 +00:00 committed by Martin K. Petersen
parent 0aaa3fad4f
commit 25b80b2c75
1 changed files with 17 additions and 1 deletions
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18
drivers/scsi/scsi_debug.c
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@ -5497,6 +5497,8 @@ static void block_unblock_all_queues(bool block)
int j;
struct sdebug_queue *sqp;
lockdep_assert_held(&sdebug_host_list_mutex);
for (j = 0, sqp = sdebug_q_arr; j < submit_queues; ++j, ++sqp)
atomic_set(&sqp->blocked, (int)block);
}
@ -5511,10 +5513,13 @@ static void tweak_cmnd_count(void)
modulo = abs(sdebug_every_nth);
if (modulo < 2)
return;
mutex_lock(&sdebug_host_list_mutex);
block_unblock_all_queues(true);
count = atomic_read(&sdebug_cmnd_count);
atomic_set(&sdebug_cmnd_count, (count / modulo) * modulo);
block_unblock_all_queues(false);
mutex_unlock(&sdebug_host_list_mutex);
}
static void clear_queue_stats(void)
@ -6036,6 +6041,7 @@ static ssize_t delay_store(struct device_driver *ddp, const char *buf,
int j, k;
struct sdebug_queue *sqp;
mutex_lock(&sdebug_host_list_mutex);
block_unblock_all_queues(true);
for (j = 0, sqp = sdebug_q_arr; j < submit_queues;
++j, ++sqp) {
@ -6051,6 +6057,7 @@ static ssize_t delay_store(struct device_driver *ddp, const char *buf,
sdebug_ndelay = 0;
}
block_unblock_all_queues(false);
mutex_unlock(&sdebug_host_list_mutex);
}
return res;
}
@ -6076,6 +6083,7 @@ static ssize_t ndelay_store(struct device_driver *ddp, const char *buf,
int j, k;
struct sdebug_queue *sqp;
mutex_lock(&sdebug_host_list_mutex);
block_unblock_all_queues(true);
for (j = 0, sqp = sdebug_q_arr; j < submit_queues;
++j, ++sqp) {
@ -6092,6 +6100,7 @@ static ssize_t ndelay_store(struct device_driver *ddp, const char *buf,
: DEF_JDELAY;
}
block_unblock_all_queues(false);
mutex_unlock(&sdebug_host_list_mutex);
}
return res;
}
@ -6405,6 +6414,7 @@ static ssize_t max_queue_store(struct device_driver *ddp, const char *buf,
if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n > 0) &&
(n <= SDEBUG_CANQUEUE) &&
(sdebug_host_max_queue == 0)) {
mutex_lock(&sdebug_host_list_mutex);
block_unblock_all_queues(true);
k = 0;
for (j = 0, sqp = sdebug_q_arr; j < submit_queues;
@ -6421,6 +6431,7 @@ static ssize_t max_queue_store(struct device_driver *ddp, const char *buf,
else
atomic_set(&retired_max_queue, 0);
block_unblock_all_queues(false);
mutex_unlock(&sdebug_host_list_mutex);
return count;
}
return -EINVAL;
@ -7352,7 +7363,9 @@ static int sdebug_change_qdepth(struct scsi_device *sdev, int qdepth)
if (!devip)
return -ENODEV;
mutex_lock(&sdebug_host_list_mutex);
block_unblock_all_queues(true);
if (qdepth > SDEBUG_CANQUEUE) {
qdepth = SDEBUG_CANQUEUE;
pr_warn("%s: requested qdepth [%d] exceeds canqueue [%d], trim\n", __func__,
@ -7363,9 +7376,12 @@ static int sdebug_change_qdepth(struct scsi_device *sdev, int qdepth)
if (qdepth != sdev->queue_depth)
scsi_change_queue_depth(sdev, qdepth);
block_unblock_all_queues(false);
mutex_unlock(&sdebug_host_list_mutex);
if (SDEBUG_OPT_Q_NOISE & sdebug_opts)
sdev_printk(KERN_INFO, sdev, "%s: qdepth=%d\n", __func__, qdepth);
block_unblock_all_queues(false);
return sdev->queue_depth;
}