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path: root/drivers/block/loop.c
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Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c18
1 files changed, 17 insertions, 1 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 102d79575895..f11b7dc16e9d 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -945,9 +945,20 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
if (!file)
goto out;
+ /*
+ * If we don't hold exclusive handle for the device, upgrade to it
+ * here to avoid changing device under exclusive owner.
+ */
+ if (!(mode & FMODE_EXCL)) {
+ bdgrab(bdev);
+ error = blkdev_get(bdev, mode | FMODE_EXCL, loop_set_fd);
+ if (error)
+ goto out_putf;
+ }
+
error = mutex_lock_killable(&loop_ctl_mutex);
if (error)
- goto out_putf;
+ goto out_bdev;
error = -EBUSY;
if (lo->lo_state != Lo_unbound)
@@ -1012,10 +1023,15 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
mutex_unlock(&loop_ctl_mutex);
if (partscan)
loop_reread_partitions(lo, bdev);
+ if (!(mode & FMODE_EXCL))
+ blkdev_put(bdev, mode | FMODE_EXCL);
return 0;
out_unlock:
mutex_unlock(&loop_ctl_mutex);
+out_bdev:
+ if (!(mode & FMODE_EXCL))
+ blkdev_put(bdev, mode | FMODE_EXCL);
out_putf:
fput(file);
out: