[PATCH] sem2mutex: mm/slab.c

Convert mm/swapfile.c's swapon_sem to swapon_mutex.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 9 insertions, 8 deletions

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 957fef43fa60..f1e69c30d203 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -25,6 +25,7 @@
 #include <linux/rmap.h>
 #include <linux/security.h>
 #include <linux/backing-dev.h>
+#include <linux/mutex.h>
 #include <linux/capability.h>
 #include <linux/syscalls.h>
 
@@ -46,12 +47,12 @@ struct swap_list_t swap_list = {-1, -1};
 
 struct swap_info_struct swap_info[MAX_SWAPFILES];
 
-static DECLARE_MUTEX(swapon_sem);
+static DEFINE_MUTEX(swapon_mutex);
 
 /*
  * We need this because the bdev->unplug_fn can sleep and we cannot
  * hold swap_lock while calling the unplug_fn. And swap_lock
- * cannot be turned into a semaphore.
+ * cannot be turned into a mutex.
  */
 static DECLARE_RWSEM(swap_unplug_sem);
 
@@ -1161,7 +1162,7 @@ asmlinkage long sys_swapoff(const char __user * specialfile)
         up_write(&swap_unplug_sem);
 
         destroy_swap_extents(p);
-        down(&swapon_sem);
+        mutex_lock(&swapon_mutex);
         spin_lock(&swap_lock);
         drain_mmlist();
 
@@ -1180,7 +1181,7 @@ asmlinkage long sys_swapoff(const char __user * specialfile)
         p->swap_map = NULL;
         p->flags = 0;
         spin_unlock(&swap_lock);
-        up(&swapon_sem);
+        mutex_unlock(&swapon_mutex);
         vfree(swap_map);
         inode = mapping->host;
         if (S_ISBLK(inode->i_mode)) {
@@ -1209,7 +1210,7 @@ static void *swap_start(struct seq_file *swap, loff_t *pos)
         int i;
         loff_t l = *pos;
 
-        down(&swapon_sem);
+        mutex_lock(&swapon_mutex);
 
         for (i = 0; i < nr_swapfiles; i++, ptr++) {
                 if (!(ptr->flags & SWP_USED) || !ptr->swap_map)
@@ -1238,7 +1239,7 @@ static void *swap_next(struct seq_file *swap, void *v, loff_t *pos)
 
 static void swap_stop(struct seq_file *swap, void *v)
 {
-        up(&swapon_sem);
+        mutex_unlock(&swapon_mutex);
 }
 
 static int swap_show(struct seq_file *swap, void *v)
@@ -1540,7 +1541,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
                 goto bad_swap;
         }
 
-        down(&swapon_sem);
+        mutex_lock(&swapon_mutex);
         spin_lock(&swap_lock);
         p->flags = SWP_ACTIVE;
         nr_swap_pages += nr_good_pages;
@@ -1566,7 +1567,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
                 swap_info[prev].next = p - swap_info;
         }
         spin_unlock(&swap_lock);
-        up(&swapon_sem);
+        mutex_unlock(&swapon_mutex);
         error = 0;
         goto out;
 bad_swap: