[PATCH 10/16] loop: Push loop_ctl_mutex down to loop_set_fd()

Jan Kara
2018-11-08T13:01:10Z

Push lo_ctl_mutex down to loop_set_fd(). We will need this to be able to
call loop_reread_partitions() without lo_ctl_mutex.

Signed-off-by: Jan Kara <jack@suse.cz>
---
drivers/block/loop.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index af79a59732b7..161e2a08f2e8 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -918,13 +918,17 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
if (!file)
goto out;

+ error = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
+ if (error)
+ goto out_putf;
+
error = -EBUSY;
if (lo->lo_state != Lo_unbound)
- goto out_putf;
+ goto out_unlock;

error = loop_validate_file(file, bdev);
if (error)
- goto out_putf;
+ goto out_unlock;

mapping = file->f_mapping;
inode = mapping->host;
@@ -936,10 +940,10 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
error = -EFBIG;
size = get_loop_size(lo, file);
if ((loff_t)(sector_t)size != size)
- goto out_putf;
+ goto out_unlock;
error = loop_prepare_queue(lo);
if (error)
- goto out_putf;
+ goto out_unlock;

error = 0;

@@ -978,11 +982,14 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
* put /dev/loopXX inode. Later in __loop_clr_fd() we bdput(bdev).
*/
bdgrab(bdev);
+ mutex_unlock(&loop_ctl_mutex);
return 0;

- out_putf:
+out_unlock:
+ mutex_unlock(&loop_ctl_mutex);
+out_putf:
fput(file);
- out:
+out:
/* This is safe: open() is still holding a reference. */
module_put(THIS_MODULE);
return error;
@@ -1460,12 +1467,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,

switch (cmd) {
case LOOP_SET_FD:
- err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
- if (err)
- return err;
- err = loop_set_fd(lo, mode, bdev, arg);
- mutex_unlock(&loop_ctl_mutex);
- break;
+ return loop_set_fd(lo, mode, bdev, arg);
case LOOP_CHANGE_FD:
err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
if (err)
--
2.16.4