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authorStefan Roese <sr@denx.de>2010-11-01 17:28:00 +0100
committerStefan Roese <sr@denx.de>2010-12-03 16:33:47 +0100
commitb1a14f8a1c2e72d5c58269d0200f722d8eec19c4 (patch)
treebe575ad7fc80882733954bc7e20140de0bc559a0
parent9a2ea578bc2f556fd92a3bcb9127d3fc9c6ee1bd (diff)
UBIFS: Change ubifsload to not read beyond the requested size
Until now ubifsload pads the destination with 0 up to a multiple of UBIFS_BLOCK_SIZE (4KiB) while reading a file to memory. This patch changes this behaviour to only read to the requested length. This is either the file length or the length/size provided as parameter to the ubifsload command. Signed-off-by: Stefan Roese <sr@denx.de>
-rw-r--r--fs/ubifs/ubifs.c71
1 files changed, 58 insertions, 13 deletions
diff --git a/fs/ubifs/ubifs.c b/fs/ubifs/ubifs.c
index 1cc31a968d..d16d2b06a7 100644
--- a/fs/ubifs/ubifs.c
+++ b/fs/ubifs/ubifs.c
@@ -3,7 +3,7 @@
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
- * (C) Copyright 2008-2009
+ * (C) Copyright 2008-2010
* Stefan Roese, DENX Software Engineering, sr@denx.de.
*
* This program is free software; you can redistribute it and/or modify it
@@ -567,7 +567,8 @@ dump:
return -EINVAL;
}
-static int do_readpage(struct ubifs_info *c, struct inode *inode, struct page *page)
+static int do_readpage(struct ubifs_info *c, struct inode *inode,
+ struct page *page, int last_block_size)
{
void *addr;
int err = 0, i;
@@ -601,17 +602,54 @@ static int do_readpage(struct ubifs_info *c, struct inode *inode, struct page *p
err = -ENOENT;
memset(addr, 0, UBIFS_BLOCK_SIZE);
} else {
- ret = read_block(inode, addr, block, dn);
- if (ret) {
- err = ret;
- if (err != -ENOENT)
+ /*
+ * Reading last block? Make sure to not write beyond
+ * the requested size in the destination buffer.
+ */
+ if (((block + 1) == beyond) || last_block_size) {
+ void *buff;
+ int dlen;
+
+ /*
+ * We need to buffer the data locally for the
+ * last block. This is to not pad the
+ * destination area to a multiple of
+ * UBIFS_BLOCK_SIZE.
+ */
+ buff = malloc(UBIFS_BLOCK_SIZE);
+ if (!buff) {
+ printf("%s: Error, malloc fails!\n",
+ __func__);
+ err = -ENOMEM;
break;
- } else if (block + 1 == beyond) {
- int dlen = le32_to_cpu(dn->size);
- int ilen = i_size & (UBIFS_BLOCK_SIZE - 1);
-
- if (ilen && ilen < dlen)
- memset(addr + ilen, 0, dlen - ilen);
+ }
+
+ /* Read block-size into temp buffer */
+ ret = read_block(inode, buff, block, dn);
+ if (ret) {
+ err = ret;
+ if (err != -ENOENT) {
+ free(buff);
+ break;
+ }
+ }
+
+ if (last_block_size)
+ dlen = last_block_size;
+ else
+ dlen = le32_to_cpu(dn->size);
+
+ /* Now copy required size back to dest */
+ memcpy(addr, buff, dlen);
+
+ free(buff);
+ } else {
+ ret = read_block(inode, addr, block, dn);
+ if (ret) {
+ err = ret;
+ if (err != -ENOENT)
+ break;
+ }
}
}
if (++i >= UBIFS_BLOCKS_PER_PAGE)
@@ -649,6 +687,7 @@ int ubifs_load(char *filename, u32 addr, u32 size)
int err = 0;
int i;
int count;
+ int last_block_size = 0;
c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
/* ubifs_findfile will resolve symlinks, so we know that we get
@@ -684,7 +723,13 @@ int ubifs_load(char *filename, u32 addr, u32 size)
page.index = 0;
page.inode = inode;
for (i = 0; i < count; i++) {
- err = do_readpage(c, inode, &page);
+ /*
+ * Make sure to not read beyond the requested size
+ */
+ if (((i + 1) == count) && (size < inode->i_size))
+ last_block_size = size - (i * PAGE_SIZE);
+
+ err = do_readpage(c, inode, &page, last_block_size);
if (err)
break;