diff options
| author | Matthias Kaehlcke <matthias@kaehlcke.net> | 2009-07-14 22:04:29 +0200 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2009-08-03 14:25:00 +0100 |
| commit | d676c11727815761e41a81b00c054b4bec452ae5 (patch) | |
| tree | 9cdc40a1142010a545e41272a0c3b5ddc0d205fc | |
| parent | 2bf961b7ccd69e108ac435c67e2b0522b403c578 (diff) | |
mtd: mtdblock: introduce mtdblks_lock
The mtdblks array and its content are prone to race conditions. Introduce
the mutex mtdblks_lock in order to solve this.
[Amended by Artem Bityutskiy]
Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
| -rw-r--r-- | drivers/mtd/mtdblock.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/mtd/mtdblock.c b/drivers/mtd/mtdblock.c index 208c6faa035..77db5ce24d9 100644 --- a/drivers/mtd/mtdblock.c +++ b/drivers/mtd/mtdblock.c @@ -29,6 +29,8 @@ static struct mtdblk_dev { enum { STATE_EMPTY, STATE_CLEAN, STATE_DIRTY } cache_state; } *mtdblks[MAX_MTD_DEVICES]; +static struct mutex mtdblks_lock; + /* * Cache stuff... * @@ -270,15 +272,19 @@ static int mtdblock_open(struct mtd_blktrans_dev *mbd) DEBUG(MTD_DEBUG_LEVEL1,"mtdblock_open\n"); + mutex_lock(&mtdblks_lock); if (mtdblks[dev]) { mtdblks[dev]->count++; + mutex_unlock(&mtdblks_lock); return 0; } /* OK, it's not open. Create cache info for it */ mtdblk = kzalloc(sizeof(struct mtdblk_dev), GFP_KERNEL); - if (!mtdblk) + if (!mtdblk) { + mutex_unlock(&mtdblks_lock); return -ENOMEM; + } mtdblk->count = 1; mtdblk->mtd = mtd; @@ -291,6 +297,7 @@ static int mtdblock_open(struct mtd_blktrans_dev *mbd) } mtdblks[dev] = mtdblk; + mutex_unlock(&mtdblks_lock); DEBUG(MTD_DEBUG_LEVEL1, "ok\n"); @@ -304,6 +311,8 @@ static int mtdblock_release(struct mtd_blktrans_dev *mbd) DEBUG(MTD_DEBUG_LEVEL1, "mtdblock_release\n"); + mutex_lock(&mtdblks_lock); + mutex_lock(&mtdblk->cache_mutex); write_cached_data(mtdblk); mutex_unlock(&mtdblk->cache_mutex); @@ -316,6 +325,9 @@ static int mtdblock_release(struct mtd_blktrans_dev *mbd) vfree(mtdblk->cache_data); kfree(mtdblk); } + + mutex_unlock(&mtdblks_lock); + DEBUG(MTD_DEBUG_LEVEL1, "ok\n"); return 0; @@ -376,6 +388,8 @@ static struct mtd_blktrans_ops mtdblock_tr = { static int __init init_mtdblock(void) { + mutex_init(&mtdblks_lock); + return register_mtd_blktrans(&mtdblock_tr); } |