From 8537874a6585251843f462c16b1684d38c887996 Mon Sep 17 00:00:00 2001 From: Tien Fong Chee Date: Mon, 11 Feb 2019 14:56:19 +0800 Subject: [PATCH] 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 Signed-off-by: Tien Fong Chee --- fs/fat/fat.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/fs/fat/fat.c b/fs/fat/fat.c index dac86ea516..f593e989ff 100644 --- 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; -- 2.25.1