diff options
| author | Omar Sandoval <osandov@fb.com> | 2018-03-27 07:39:12 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-03-27 23:21:12 +0300 |
| commit | 3148ffbdb9162baa28545809d675d3bf9339d6a1 (patch) | |
| tree | 495edae516c7b4d02237bdd041b88fc059a3fc0d | |
| parent | 2d1d4c1e591fd40bd7dafd868a249d7d00e215d5 (diff) | |
| download | linux-3148ffbdb9162baa28545809d675d3bf9339d6a1.tar.xz | |
loop: use killable lock in ioctls
Even after the previous patch to drop lo_ctl_mutex while calling
vfs_getattr(), there are other cases where we can end up sleeping for a
long time while holding lo_ctl_mutex. Let's avoid the uninterruptible
sleep from the ioctls.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | drivers/block/loop.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index c633b68b69ff..f34863af332a 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1360,7 +1360,10 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode, struct loop_device *lo = bdev->bd_disk->private_data; int err; - mutex_lock_nested(&lo->lo_ctl_mutex, 1); + err = mutex_lock_killable_nested(&lo->lo_ctl_mutex, 1); + if (err) + goto out_unlocked; + switch (cmd) { case LOOP_SET_FD: err = loop_set_fd(lo, mode, bdev, arg); @@ -1545,16 +1548,20 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode, switch(cmd) { case LOOP_SET_STATUS: - mutex_lock(&lo->lo_ctl_mutex); - err = loop_set_status_compat( - lo, (const struct compat_loop_info __user *) arg); - mutex_unlock(&lo->lo_ctl_mutex); + err = mutex_lock_killable(&lo->lo_ctl_mutex); + if (!err) { + err = loop_set_status_compat(lo, + (const struct compat_loop_info __user *)arg); + mutex_unlock(&lo->lo_ctl_mutex); + } break; case LOOP_GET_STATUS: - mutex_lock(&lo->lo_ctl_mutex); - err = loop_get_status_compat( - lo, (struct compat_loop_info __user *) arg); - /* loop_get_status() unlocks lo_ctl_mutex */ + err = mutex_lock_killable(&lo->lo_ctl_mutex); + if (!err) { + err = loop_get_status_compat(lo, + (struct compat_loop_info __user *)arg); + /* loop_get_status() unlocks lo_ctl_mutex */ + } break; case LOOP_SET_CAPACITY: case LOOP_CLR_FD: @@ -1959,7 +1966,9 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd, ret = loop_lookup(&lo, parm); if (ret < 0) break; - mutex_lock(&lo->lo_ctl_mutex); + ret = mutex_lock_killable(&lo->lo_ctl_mutex); + if (ret) + break; if (lo->lo_state != Lo_unbound) { ret = -EBUSY; mutex_unlock(&lo->lo_ctl_mutex); |