fs/fat: Do not write unmodified fat entries to disk
The code caches 6 sectors of the FAT. On FAT traversal, the old contents
needs to be flushed to disk, but only if any FAT entries had been modified.
Explicitly flag the buffer on modification.
Currently, creating a new file traverses the whole FAT up to the first
free cluster and rewrites the on-disk blocks.
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 826bd85..df9f2b5 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -876,6 +876,7 @@
}
mydata->fatbufnum = -1;
+ mydata->fat_dirty = 0;
mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
if (mydata->fatbuf == NULL) {
debug("Error: allocating memory\n");