jbd2: Convert jbd2_slab_create_sem to mutex

jbd2_slab_create_sem is used as a mutex, so make it one.

[ akpm muttered: We may as well make it local to
jbd2_journal_create_slab() also. ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <alpine.LFD.2.00.1010162231480.2496@localhost6.localdomain6>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 538417c..c590d15 100644 (file)
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1838,7 +1838,6 @@ size_t journal_tag_bytes(journal_t *journal)
  */
 #define JBD2_MAX_SLABS 8
 static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS];
-static DECLARE_MUTEX(jbd2_slab_create_sem);
 
 static const char *jbd2_slab_names[JBD2_MAX_SLABS] = {
        "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k",
@@ -1859,6 +1858,7 @@ static void jbd2_journal_destroy_slabs(void)
 
 static int jbd2_journal_create_slab(size_t size)
 {
+       static DEFINE_MUTEX(jbd2_slab_create_mutex);
        int i = order_base_2(size) - 10;
        size_t slab_size;
 
@@ -1870,16 +1870,16 @@ static int jbd2_journal_create_slab(size_t size)
 
        if (unlikely(i < 0))
                i = 0;
-       down(&jbd2_slab_create_sem);
+       mutex_lock(&jbd2_slab_create_mutex);
        if (jbd2_slab[i]) {
-               up(&jbd2_slab_create_sem);
+               mutex_unlock(&jbd2_slab_create_mutex);
                return 0;       /* Already created */
        }
 
        slab_size = 1 << (i+10);
        jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size,
                                         slab_size, 0, NULL);
-       up(&jbd2_slab_create_sem);
+       mutex_unlock(&jbd2_slab_create_mutex);
        if (!jbd2_slab[i]) {
                printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n");
                return -ENOMEM;