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>
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 424ca5f..f1f0671 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -233,6 +233,7 @@
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 af65912..6c6d807 100644
--- a/drivers/mtd/mtdblock.c
+++ b/drivers/mtd/mtdblock.c
@@ -321,8 +321,12 @@
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);
}
