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authorAlexander Stein <alexander.stein@systec-electronic.com>2012-01-10 16:26:58 +0400
committerDavid Woodhouse <David.Woodhouse@intel.com>2012-03-27 03:11:11 +0400
commit70d5098a4b1551864dd7df43f67b7f606a1a6438 (patch)
tree288f6f9cdb1866ea9648c6590448254c40af2c81
parent2ff5e1532dd37e1bd8ac72da3f7f0e2b310102fb (diff)
downloadlinux-70d5098a4b1551864dd7df43f67b7f606a1a6438.tar.xz
mtd: mtdblock: call mtd_sync() only if opened for write
Because it is useless to call it if the device is opened in R/O mode, and also harmful: on CFI NOR flash it may block for long time waiting for erase operations to complete is another partition with a R/W file-system on this chip. Artem Bityutskiy: write commit message, amend the patch to match the latest tree (we use mtd_sync(), not mtd->sync() nowadays). Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
-rw-r--r--drivers/mtd/mtd_blkdevs.c1
-rw-r--r--drivers/mtd/mtdblock.c8
-rw-r--r--include/linux/mtd/blktrans.h1
3 files changed, 8 insertions, 2 deletions
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 424ca5f93c6c..f1f06715d4e0 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -233,6 +233,7 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
ret = __get_mtd_device(dev->mtd);
if (ret)
goto error_release;
+ dev->file_mode = mode;
unlock:
dev->open++;
diff --git a/drivers/mtd/mtdblock.c b/drivers/mtd/mtdblock.c
index af6591237b9b..6c6d80736fad 100644
--- a/drivers/mtd/mtdblock.c
+++ b/drivers/mtd/mtdblock.c
@@ -321,8 +321,12 @@ static int mtdblock_release(struct mtd_blktrans_dev *mbd)
mutex_unlock(&mtdblk->cache_mutex);
if (!--mtdblk->count) {
- /* It was the last usage. Free the cache */
- mtd_sync(mbd->mtd);
+ /*
+ * It was the last usage. Free the cache, but only sync if
+ * opened for writing.
+ */
+ if (mbd->file_mode & FMODE_WRITE)
+ mtd_sync(mbd->mtd);
vfree(mtdblk->cache_data);
}
diff --git a/include/linux/mtd/blktrans.h b/include/linux/mtd/blktrans.h
index 1bbd9f289245..ed270bd2e4df 100644
--- a/include/linux/mtd/blktrans.h
+++ b/include/linux/mtd/blktrans.h
@@ -47,6 +47,7 @@ struct mtd_blktrans_dev {
struct request_queue *rq;
spinlock_t queue_lock;
void *priv;
+ fmode_t file_mode;
};
struct mtd_blktrans_ops {