4.19-stable review patch. If anyone has any objections, please let me know.
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From: Jan Kara jack@suse.cz
commit 4a5ce9ba5877e4640200d84a735361306ad1a1b8 upstream.
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 Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/block/loop.c | 37 ++++++++++--------------------------- 1 file changed, 10 insertions(+), 27 deletions(-)
--- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1233,6 +1233,9 @@ loop_get_status(struct loop_device *lo, 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; @@ -1347,10 +1350,8 @@ loop_get_status_old(struct loop_device * 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); @@ -1365,10 +1366,8 @@ loop_get_status64(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 && copy_to_user(arg, &info64, sizeof(info64))) err = -EFAULT; @@ -1478,12 +1477,7 @@ static int lo_ioctl(struct block_device } 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)) { @@ -1496,12 +1490,7 @@ static int lo_ioctl(struct block_device } 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: @@ -1626,10 +1615,8 @@ loop_get_status_compat(struct loop_devic 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); @@ -1652,12 +1639,8 @@ static int lo_compat_ioctl(struct block_ } 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: