block: loop: introduce lo_discard() and lo_req_flush()

[cascardo/linux.git] / drivers / block / loop.c

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d958901..018af27 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -417,6 +417,40 @@ lo_receive(struct loop_device *lo, struct request *rq, int bsize, loff_t pos)
        return 0;
 }
 
+static int lo_discard(struct loop_device *lo, struct request *rq, loff_t pos)
+{
+       /*
+        * We use punch hole to reclaim the free space used by the
+        * image a.k.a. discard. However we do not support discard if
+        * encryption is enabled, because it may give an attacker
+        * useful information.
+        */
+       struct file *file = lo->lo_backing_file;
+       int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
+       int ret;
+
+       if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size) {
+               ret = -EOPNOTSUPP;
+               goto out;
+       }
+
+       ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq));
+       if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP))
+               ret = -EIO;
+ out:
+       return ret;
+}
+
+static int lo_req_flush(struct loop_device *lo, struct request *rq)
+{
+       struct file *file = lo->lo_backing_file;
+       int ret = vfs_fsync(file, 0);
+       if (unlikely(ret && ret != -EINVAL))
+               ret = -EIO;
+
+       return ret;
+}
+
 static int do_req_filebacked(struct loop_device *lo, struct request *rq)
 {
        loff_t pos;
@@ -425,46 +459,19 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
        pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;
 
        if (rq->cmd_flags & REQ_WRITE) {
-               struct file *file = lo->lo_backing_file;
-
-               if (rq->cmd_flags & REQ_FLUSH) {
-                       ret = vfs_fsync(file, 0);
-                       if (unlikely(ret && ret != -EINVAL)) {
-                               ret = -EIO;
-                               goto out;
-                       }
-               }
 
-               /*
-                * We use punch hole to reclaim the free space used by the
-                * image a.k.a. discard. However we do not support discard if
-                * encryption is enabled, because it may give an attacker
-                * useful information.
-                */
+               if (rq->cmd_flags & REQ_FLUSH)
+                       ret = lo_req_flush(lo, rq);
+
                if (rq->cmd_flags & REQ_DISCARD) {
-                       struct file *file = lo->lo_backing_file;
-                       int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
-
-                       if ((!file->f_op->fallocate) ||
-                           lo->lo_encrypt_key_size) {
-                               ret = -EOPNOTSUPP;
-                               goto out;
-                       }
-                       ret = file->f_op->fallocate(file, mode, pos,
-                                                   blk_rq_bytes(rq));
-                       if (unlikely(ret && ret != -EINVAL &&
-                                    ret != -EOPNOTSUPP))
-                               ret = -EIO;
+                       ret = lo_discard(lo, rq, pos);
                        goto out;
                }
 
                ret = lo_send(lo, rq, pos);
 
-               if ((rq->cmd_flags & REQ_FUA) && !ret) {
-                       ret = vfs_fsync(file, 0);
-                       if (unlikely(ret && ret != -EINVAL))
-                               ret = -EIO;
-               }
+               if ((rq->cmd_flags & REQ_FUA) && !ret)
+                       ret = lo_req_flush(lo, rq);
        } else
                ret = lo_receive(lo, rq, lo->lo_blocksize, pos);