target/linux/generic/patches-3.10/502-yaffs-Switch-from-semaphores-to-mutexes.patch

   1 From c0c289363e84c53b5872f7c0c5069045096dca07 Mon Sep 17 00:00:00 2001
   2 From: Charles Manning <cdhmanning@gmail.com>
   3 Date: Wed, 3 Nov 2010 16:01:12 +1300
   4 Subject: [PATCH] yaffs: Switch from semaphores to mutexes
   5
   6 commit 73c54aa8c1de3f61a4c211cd47431293a6092f18 upstream.
   7
   8 Mutex is faster and init_MUTEX has been deprecated, so we'll just switch
   9 to mutexes.
  10
  11 Signed-off-by: Charles Manning <cdhmanning@gmail.com>
  12 ---
  13  yaffs_linux.h     |    2 +-
  14  yaffs_vfs.c       |   24 ++++++++++++------------
  15  yaffs_vfs_multi.c |   26 +++++++++++++-------------
  16  3 files changed, 26 insertions(+), 26 deletions(-)
  17
  18 --- a/fs/yaffs2/yaffs_linux.h
  19 +++ b/fs/yaffs2/yaffs_linux.h
  20 @@ -25,7 +25,7 @@ struct yaffs_LinuxContext {
  21         struct super_block * superBlock;
  22         struct task_struct *bgThread; /* Background thread for this device */
  23         int bgRunning;
  24 -        struct semaphore grossLock;     /* Gross locking semaphore */
  25 +       struct mutex grossLock; /* Gross locking mutex*/
  26         __u8 *spareBuffer;      /* For mtdif2 use. Don't know the size of the buffer
  27                                  * at compile time so we have to allocate it.
  28                                  */
  29 --- a/fs/yaffs2/yaffs_vfs_glue.c
  30 +++ b/fs/yaffs2/yaffs_vfs_glue.c
  31 @@ -515,14 +515,14 @@ static unsigned yaffs_gc_control_callbac
  32  static void yaffs_gross_lock(yaffs_dev_t *dev)
  33  {
  34         T(YAFFS_TRACE_LOCK, (TSTR("yaffs locking %p\n"), current));
  35 -       down(&(yaffs_dev_to_lc(dev)->grossLock));
  36 +       mutex_lock(&(yaffs_dev_to_lc(dev)->grossLock));
  37         T(YAFFS_TRACE_LOCK, (TSTR("yaffs locked %p\n"), current));
  38  }
  39
  40  static void yaffs_gross_unlock(yaffs_dev_t *dev)
  41  {
  42         T(YAFFS_TRACE_LOCK, (TSTR("yaffs unlocking %p\n"), current));
  43 -       up(&(yaffs_dev_to_lc(dev)->grossLock));
  44 +       mutex_unlock(&(yaffs_dev_to_lc(dev)->grossLock));
  45  }
  46
  47  #ifdef YAFFS_COMPILE_EXPORTFS
  48 @@ -2542,7 +2542,7 @@ static void yaffs_read_inode(struct inod
  49  #endif
  50
  51  static YLIST_HEAD(yaffs_context_list);
  52 -struct semaphore yaffs_context_lock;
  53 +struct mutex yaffs_context_lock;
  54
  55  static void yaffs_put_super(struct super_block *sb)
  56  {
  57 @@ -2568,9 +2568,9 @@ static void yaffs_put_super(struct super
  58
  59         yaffs_gross_unlock(dev);
  60
  61 -       down(&yaffs_context_lock);
  62 +       mutex_lock(&yaffs_context_lock);
  63         ylist_del_init(&(yaffs_dev_to_lc(dev)->contextList));
  64 -       up(&yaffs_context_lock);
  65 +       mutex_unlock(&yaffs_context_lock);
  66
  67         if (yaffs_dev_to_lc(dev)->spareBuffer) {
  68                 YFREE(yaffs_dev_to_lc(dev)->spareBuffer);
  69 @@ -3016,7 +3016,7 @@ static struct super_block *yaffs_interna
  70         param->skip_checkpt_rd = options.skip_checkpoint_read;
  71         param->skip_checkpt_wr = options.skip_checkpoint_write;
  72
  73 -       down(&yaffs_context_lock);
  74 +       mutex_lock(&yaffs_context_lock);
  75         /* Get a mount id */
  76         found = 0;
  77         for(mount_id=0; ! found; mount_id++){
  78 @@ -3030,13 +3030,13 @@ static struct super_block *yaffs_interna
  79         context->mount_id = mount_id;
  80
  81         ylist_add_tail(&(yaffs_dev_to_lc(dev)->contextList), &yaffs_context_list);
  82 -       up(&yaffs_context_lock);
  83 +       mutex_unlock(&yaffs_context_lock);
  84
  85          /* Directory search handling...*/
  86          YINIT_LIST_HEAD(&(yaffs_dev_to_lc(dev)->searchContexts));
  87          param->remove_obj_fn = yaffs_remove_obj_callback;
  88
  89 -       init_MUTEX(&(yaffs_dev_to_lc(dev)->grossLock));
  90 +       mutex_init(&(yaffs_dev_to_lc(dev)->grossLock));
  91
  92         yaffs_gross_lock(dev);
  93
  94 @@ -3268,7 +3268,7 @@ static int yaffs_proc_read(char *page,
  95         else {
  96                 step-=2;
  97
  98 -               down(&yaffs_context_lock);
  99 +               mutex_lock(&yaffs_context_lock);
 100
 101                 /* Locate and print the Nth entry.  Order N-squared but N is small. */
 102                 ylist_for_each(item, &yaffs_context_list) {
 103 @@ -3287,7 +3287,7 @@ static int yaffs_proc_read(char *page,
 104
 105                         break;
 106                 }
 107 -               up(&yaffs_context_lock);
 108 +               mutex_unlock(&yaffs_context_lock);
 109         }
 110
 111         return buf - page < count ? buf - page : count;
 112 @@ -3301,7 +3301,7 @@ static int yaffs_stats_proc_read(char *p
 113         char *buf = page;
 114         int n = 0;
 115
 116 -       down(&yaffs_context_lock);
 117 +       mutex_lock(&yaffs_context_lock);
 118
 119         /* Locate and print the Nth entry.  Order N-squared but N is small. */
 120         ylist_for_each(item, &yaffs_context_list) {
 121 @@ -3317,7 +3317,7 @@ static int yaffs_stats_proc_read(char *p
 122                                 dev->bg_gcs, dev->oldest_dirty_gc_count,
 123                                 dev->n_obj, dev->n_tnodes);
 124         }
 125 -       up(&yaffs_context_lock);
 126 +       mutex_unlock(&yaffs_context_lock);
 127
 128
 129         return buf - page < count ? buf - page : count;
 130 @@ -3494,7 +3494,7 @@ static int __init init_yaffs_fs(void)
 131
 132
 133
 134 -       init_MUTEX(&yaffs_context_lock);
 135 +       mutex_init(&yaffs_context_lock);
 136
 137         /* Install the proc_fs entries */
 138         my_proc_entry = create_proc_entry("yaffs",