sys_swapon: remove did_down variable

Since mutex_lock(&inode->i_mutex) is called just after setting inode,
did_down is always equivalent to (inode && S_ISREG(inode->i_mode)).

Use this fact to remove the did_down variable.

Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Tested-by: Eric B Munson <emunson@mgebm.net>
Acked-by: Eric B Munson <emunson@mgebm.net>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 6 deletions

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 6f25ece88c4a..b261e55e0b82 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1907,7 +1907,6 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
         unsigned char *swap_map = NULL;
         struct page *page = NULL;
         struct inode *inode = NULL;
-        int did_down = 0;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EPERM;
@@ -1962,7 +1961,6 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
         } else if (S_ISREG(inode->i_mode)) {
                 p->bdev = inode->i_sb->s_bdev;
                 mutex_lock(&inode->i_mutex);
-                did_down = 1;
                 if (IS_SWAPFILE(inode)) {
                         error = -EBUSY;
                         goto bad_swap;
@@ -2154,10 +2152,8 @@ bad_swap_2:
         spin_unlock(&swap_lock);
         vfree(swap_map);
         if (swap_file) {
-                if (did_down) {
+                if (inode && S_ISREG(inode->i_mode))
                         mutex_unlock(&inode->i_mutex);
-                        did_down = 0;
-                }
                 filp_close(swap_file, NULL);
         }
 out:
@@ -2167,7 +2163,7 @@ out:
         }
         if (name)
                 putname(name);
-        if (did_down) {
+        if (inode && S_ISREG(inode->i_mode)) {
                 if (!error)
                         inode->i_flags |= S_SWAPFILE;
                 mutex_unlock(&inode->i_mutex);