[PATCH 08/16] loop: Push loop_ctl_mutex down to loop_get_status()

Jan Kara
2018-11-08T13:01:08Z

Push loop_ctl_mutex down to loop_get_status() to avoid the unusual
convention that the function gets called with loop_ctl_mutex held and
releases it.

Signed-off-by: Jan Kara <jack@suse.cz>
---
drivers/block/loop.c | 37 ++++++++++---------------------------
1 file changed, 10 insertions(+), 27 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d8a7b5da881b..2e814f8af4df 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1232,6 +1232,9 @@ loop_get_status(struct loop_device *lo, struct loop_info64 *info)
struct kstat stat;
int ret;

+ ret = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
+ if (ret)
+ return ret;
if (lo->lo_state != Lo_bound) {
mutex_unlock(&loop_ctl_mutex);
return -ENXIO;
@@ -1346,10 +1349,8 @@ loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) {
struct loop_info64 info64;
int err;

- if (!arg) {
- mutex_unlock(&loop_ctl_mutex);
+ if (!arg)
return -EINVAL;
- }
err = loop_get_status(lo, &info64);
if (!err)
err = loop_info64_to_old(&info64, &info);
@@ -1364,10 +1365,8 @@ loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) {
struct loop_info64 info64;
int err;

- if (!arg) {
- mutex_unlock(&loop_ctl_mutex);
+ if (!arg)
return -EINVAL;
- }
err = loop_get_status(lo, &info64);
if (!err && copy_to_user(arg, &info64, sizeof(info64)))
err = -EFAULT;
@@ -1477,12 +1476,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
}
break;
case LOOP_GET_STATUS:
- err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
- if (err)
- return err;
- err = loop_get_status_old(lo, (struct loop_info __user *) arg);
- /* loop_get_status() unlocks loop_ctl_mutex */
- break;
+ return loop_get_status_old(lo, (struct loop_info __user *) arg);
case LOOP_SET_STATUS64:
err = -EPERM;
if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
@@ -1495,12 +1489,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
}
break;
case LOOP_GET_STATUS64:
- err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
- if (err)
- return err;
- err = loop_get_status64(lo, (struct loop_info64 __user *) arg);
- /* loop_get_status() unlocks loop_ctl_mutex */
- break;
+ return loop_get_status64(lo, (struct loop_info64 __user *) arg);
case LOOP_SET_CAPACITY:
case LOOP_SET_DIRECT_IO:
case LOOP_SET_BLOCK_SIZE:
@@ -1625,10 +1614,8 @@ loop_get_status_compat(struct loop_device *lo,
struct loop_info64 info64;
int err;

- if (!arg) {
- mutex_unlock(&loop_ctl_mutex);
+ if (!arg)
return -EINVAL;
- }
err = loop_get_status(lo, &info64);
if (!err)
err = loop_info64_to_compat(&info64, arg);
@@ -1651,12 +1638,8 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
}
break;
case LOOP_GET_STATUS:
- err = mutex_lock_killable(&loop_ctl_mutex);
- if (!err) {
- err = loop_get_status_compat(lo,
- (struct compat_loop_info __user *)arg);
- /* loop_get_status() unlocks loop_ctl_mutex */
- }
+ err = loop_get_status_compat(lo,
+ (struct compat_loop_info __user *)arg);
break;
case LOOP_SET_CAPACITY:
case LOOP_CLR_FD:
--
2.16.4