btrfs: fix memory leak in btrfs_defrag_file

kmemleak found this:
unreferenced object 0xffff8801b64af968 (size 512):
  comm "btrfs-cleaner", pid 3317, jiffies 4306810886 (age 903.272s)
  hex dump (first 32 bytes):
    00 82 01 07 00 ea ff ff c0 83 01 07 00 ea ff ff  ................
    80 82 01 07 00 ea ff ff c0 87 01 07 00 ea ff ff  ................
  backtrace:
    [<ffffffff816875cc>] kmemleak_alloc+0x5c/0xc0
    [<ffffffff8114aec3>] kmem_cache_alloc_trace+0x163/0x240
    [<ffffffff8127a290>] btrfs_defrag_file+0xf0/0xb20
    [<ffffffff8125d9a5>] btrfs_run_defrag_inodes+0x165/0x210
    [<ffffffff812479d7>] cleaner_kthread+0x177/0x190
    [<ffffffff81075c7d>] kthread+0x8d/0xa0
    [<ffffffff816af5f4>] kernel_thread_helper+0x4/0x10
    [<ffffffffffffffff>] 0xffffffffffffffff

"pages" is not always freed. Fix it removing the unnecesary additional return.

Signed-off-by: Diego Calleja <diegocg@gmail.com>

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index d2b53eb..8ccc106 100644 (file)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1140,9 +1140,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
                btrfs_set_super_incompat_flags(disk_super, features);
        }
 
-       if (!file)
-               kfree(ra);
-       return defrag_count;
+       ret = defrag_count;
 
 out_ra:
        if (!file)