fs/fat: reduce data size for FAT_WRITE

Allocated tmpbuf_cluster dynamically to reduce the data size added by
compiling with CONFIG_FAT_WRITE.

Reported-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index b16a39d..a2682b5 100644 (file)
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -500,8 +500,6 @@ flush_dir(fat_itr *itr)
                           nsects * mydata->sect_size);
 }
 
-static __u8 tmpbuf_cluster[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN);
-
 /*
  * Read and modify data on existing and consecutive cluster blocks
  */
@@ -509,6 +507,7 @@ static int
 get_set_cluster(fsdata *mydata, __u32 clustnum, loff_t pos, __u8 *buffer,
                loff_t size, loff_t *gotsize)
 {
+       static u8 *tmpbuf_cluster;
        unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
        __u32 startsect;
        loff_t wsize;
@@ -518,6 +517,12 @@ get_set_cluster(fsdata *mydata, __u32 clustnum, loff_t pos, __u8 *buffer,
        if (!size)
                return 0;
 
+       if (!tmpbuf_cluster) {
+               tmpbuf_cluster = memalign(ARCH_DMA_MINALIGN, MAX_CLUSTSIZE);
+               if (!tmpbuf_cluster)
+                       return -1;
+       }
+
        assert(pos < bytesperclust);
        startsect = clust_to_sect(mydata, clustnum);