mtd: check for Seama magic early when fixing MD5

This avoid long (and unneeded) process of reading all data in case of
running on MTD not containig Seama entity.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

Backport of r49304

git-svn-id: svn://svn.openwrt.org/openwrt/branches/chaos_calmer@49305 3c298f89-4303-0410-b956-a3cf2f4a3e73
This commit is contained in:
Rafał Miłecki
2016-05-09 09:55:35 +00:00
committed by Luka Perkov
parent c3c7d8b142
commit 7a4273314a

View File

@@ -53,7 +53,7 @@ ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
int
seama_fix_md5(char *buf, size_t len)
{
struct seama_hdr *shdr;
struct seama_hdr *shdr = (struct seama_hdr *) buf;
char *data;
size_t msize;
size_t isize;
@@ -64,12 +64,6 @@ seama_fix_md5(char *buf, size_t len)
if (len < sizeof(struct seama_hdr))
return -1;
shdr = (struct seama_hdr *) buf;
if (shdr->magic != htonl(SEAMA_MAGIC)) {
fprintf(stderr, "no SEAMA header found\n");
return -1;
}
isize = ntohl(shdr->size);
msize = ntohs(shdr->metasize);
if (isize == 0) {
@@ -115,9 +109,11 @@ int
mtd_fixseama(const char *mtd, size_t offset)
{
int fd;
char *first_block;
char *buf;
ssize_t res;
size_t block_offset;
struct seama_hdr *shdr;
if (quiet < 2)
fprintf(stderr, "Trying to fix SEAMA header in %s at 0x%x...\n",
@@ -138,6 +134,24 @@ mtd_fixseama(const char *mtd, size_t offset)
exit(1);
}
first_block = malloc(erasesize);
if (!first_block) {
perror("malloc");
exit(1);
}
res = pread(fd, first_block, erasesize, block_offset);
if (res != erasesize) {
perror("pread");
exit(1);
}
shdr = (struct seama_hdr *)first_block;
if (shdr->magic != htonl(SEAMA_MAGIC)) {
fprintf(stderr, "No SEAMA header found\n");
return -1;
}
buf = malloc(mtdsize);
if (!buf) {
perror("malloc");