2022-05-16 09:46:19

by mingzhe.zou

Subject: [PATCH v2] scsi: target: fixup incorrect use of 'cpumask_t'

From: mingzhe <[email protected]>

In commit d72d827f2f26, I used 'cpumask_t' incorrectly.
```
void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
{
int ord, cpu;
cpumask_t conn_allowed_cpumask;
......
}

static ssize_t lio_target_wwn_cpus_allowed_list_store(
struct config_item *item, const char *page, size_t count)
{
int ret;
char *orig;
cpumask_t new_allowed_cpumask;
......
}
```

So, that the correct pattern should be as follows:
```
cpumask_var_t mask;

if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
return -ENOMEM;
... use 'mask' here as a ...
free_cpumask_var(mask);
```

Fixes: d72d827f2f26 ("scsi: target: Add iscsi/cpus_allowed_list in configfs")
Reported-by: Test Bot <[email protected]>
Signed-off-by: mingzhe <[email protected]>
---
drivers/target/iscsi/iscsi_target.c | 32 ++++++++++++++------
drivers/target/iscsi/iscsi_target_configfs.c | 24 +++++++++------
2 files changed, 36 insertions(+), 20 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 6fe6a6bab3f4..ddf6c2a7212b 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -3596,10 +3596,7 @@ static int iscsit_send_reject(
void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
{
int ord, cpu;
- cpumask_t conn_allowed_cpumask;
-
- cpumask_and(&conn_allowed_cpumask, iscsit_global->allowed_cpumask,
- cpu_online_mask);
+ cpumask_var_t conn_allowed_cpumask;

/*
* bitmap_id is assigned from iscsit_global->ts_bitmap from
@@ -3609,13 +3606,28 @@ void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
* iSCSI connection's RX/TX threads will be scheduled to
* execute upon.
*/
- cpumask_clear(conn->conn_cpumask);
- ord = conn->bitmap_id % cpumask_weight(&conn_allowed_cpumask);
- for_each_cpu(cpu, &conn_allowed_cpumask) {
- if (ord-- == 0) {
- cpumask_set_cpu(cpu, conn->conn_cpumask);
- return;
+ if (!zalloc_cpumask_var(&conn_allowed_cpumask, GFP_KERNEL)) {
+ ord = conn->bitmap_id % cpumask_weight(cpu_online_mask);
+ for_each_online_cpu(cpu) {
+ if (ord-- == 0) {
+ cpumask_set_cpu(cpu, conn->conn_cpumask);
+ return;
+ }
+ }
+ } else {
+ cpumask_and(conn_allowed_cpumask, iscsit_global->allowed_cpumask,
+ cpu_online_mask);
+
+ cpumask_clear(conn->conn_cpumask);
+ ord = conn->bitmap_id % cpumask_weight(conn_allowed_cpumask);
+ for_each_cpu(cpu, conn_allowed_cpumask) {
+ if (ord-- == 0) {
+ cpumask_set_cpu(cpu, conn->conn_cpumask);
+ free_cpumask_var(conn_allowed_cpumask);
+ return;
+ }
}
+ free_cpumask_var(conn_allowed_cpumask);
}
/*
* This should never be reached..
diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c
index 0cedcfe207b5..57b4fd56d92a 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -1137,23 +1137,27 @@ static ssize_t lio_target_wwn_cpus_allowed_list_show(
static ssize_t lio_target_wwn_cpus_allowed_list_store(
struct config_item *item, const char *page, size_t count)
{
- int ret;
+ int ret = -ENOMEM;
char *orig;
- cpumask_t new_allowed_cpumask;
+ cpumask_var_t new_allowed_cpumask;
+
+ if (!zalloc_cpumask_var(&new_allowed_cpumask, GFP_KERNEL))
+ goto out;

orig = kstrdup(page, GFP_KERNEL);
if (!orig)
- return -ENOMEM;
+ goto out_free_cpumask;

- cpumask_clear(&new_allowed_cpumask);
- ret = cpulist_parse(orig, &new_allowed_cpumask);
+ ret = cpulist_parse(orig, new_allowed_cpumask);
+ if (!ret)
+ cpumask_copy(iscsit_global->allowed_cpumask,
+ new_allowed_cpumask);

kfree(orig);
- if (ret != 0)
- return ret;
-
- cpumask_copy(iscsit_global->allowed_cpumask, &new_allowed_cpumask);
- return count;
+out_free_cpumask:
+ free_cpumask_var(new_allowed_cpumask);
+out:
+ return ret ? ret : count;
}

CONFIGFS_ATTR(lio_target_wwn_, cpus_allowed_list);
--
2.17.1

2022-05-18 03:49:31

by Mike Christie

Subject: Re: [PATCH v2] scsi: target: fixup incorrect use of 'cpumask_t'

On 5/16/22 12:47 AM, [email protected] wrote:
> From: mingzhe <[email protected]>
>
> In commit d72d827f2f26, I used 'cpumask_t' incorrectly.
> ```
> void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
> {
> int ord, cpu;
> cpumask_t conn_allowed_cpumask;
> ......
> }
>
> static ssize_t lio_target_wwn_cpus_allowed_list_store(
> struct config_item *item, const char *page, size_t count)
> {
> int ret;
> char *orig;
> cpumask_t new_allowed_cpumask;
> ......
> }
> ```
>
> So, that the correct pattern should be as follows:
> ```
> cpumask_var_t mask;
>
> if (!zalloc_cpumask_var(&mask, GFP_KERNEL))
> return -ENOMEM;
> ... use 'mask' here as a ...
> free_cpumask_var(mask);
> ```
>
> Fixes: d72d827f2f26 ("scsi: target: Add iscsi/cpus_allowed_list in configfs")
> Reported-by: Test Bot <[email protected]>
> Signed-off-by: mingzhe <[email protected]>
>

Reviewed-by: Mike Christie <[email protected]>

2022-05-18 04:17:22

by Martin K. Petersen

Subject: Re: [PATCH v2] scsi: target: fixup incorrect use of 'cpumask_t'

On Mon, 16 May 2022 13:47:21 +0800, [email protected] wrote:

> From: mingzhe <[email protected]>
>
> In commit d72d827f2f26, I used 'cpumask_t' incorrectly.
> ```
> void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
> {
> int ord, cpu;
> cpumask_t conn_allowed_cpumask;
> ......
> }
>
> [...]

Applied to 5.18/scsi-fixes, thanks!

[1/1] scsi: target: fixup incorrect use of 'cpumask_t'
https://git.kernel.org/mkp/scsi/c/525f447f88b1

--
Martin K. Petersen Oracle Linux Engineering