fs: fat: dynamically allocate memory for temporary buffer

Drop the statically allocated get_contents_vfatname_block and
dynamically allocate a buffer only if required. This saves
64KiB of memory.

Signed-off-by: Stefan Agner <stefan.ag...@toradex.com>
Signed-off-by: Tien Fong Chee <tien.fong.chee@intel.com>

diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index dac86ea5163c486a3561fc400c6f554a805da764..f593e989ff0628a3fd63cc3186f1f8d5d681357c 100644 (file)
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -306,9 +306,6 @@ get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
  * into 'buffer'.
  * Update the number of bytes read in *gotsize or return -1 on fatal errors.
  */
-__u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
-       __aligned(ARCH_DMA_MINALIGN);
-
 static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
                        __u8 *buffer, loff_t maxsize, loff_t *gotsize)
 {
@@ -351,15 +348,24 @@ static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
 
        /* align to beginning of next cluster if any */
        if (pos) {
+               __u8 *tmp_buffer;
+
                actsize = min(filesize, (loff_t)bytesperclust);
-               if (get_cluster(mydata, curclust, get_contents_vfatname_block,
-                               (int)actsize) != 0) {
+               tmp_buffer = malloc_cache_aligned(actsize);
+               if (!tmp_buffer) {
+                       debug("Error: allocating buffer\n");
+                       return -ENOMEM;
+               }
+
+               if (get_cluster(mydata, curclust, tmp_buffer, actsize) != 0) {
                        printf("Error reading cluster\n");
+                       free(tmp_buffer);
                        return -1;
                }
                filesize -= actsize;
                actsize -= pos;
-               memcpy(buffer, get_contents_vfatname_block + pos, actsize);
+               memcpy(buffer, tmp_buffer + pos, actsize);
+               free(tmp_buffer);
                *gotsize += actsize;
                if (!filesize)
                        return 0;