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btrfs-progs: sb-mod: add devid to the modifiable list 

We need this patch to create a crafted image with bogus devid.

For example:
./btrfs-sb-mod devid =0

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Anand Jain 2020-10-07 18:08:05 +08:00 committed by David Sterba
parent 4179885cf9
commit c875145cb3
1 changed files with 21 additions and 1 deletions
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22
btrfs-sb-mod.c
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@ -139,6 +139,7 @@ struct sb_field {
{ .name = "log_root_level", .type = TYPE_U8 },
{ .name = "cache_generation", .type = TYPE_U64 },
{ .name = "uuid_tree_generation", .type = TYPE_U64 },
{ .name = "devid", .type = TYPE_U64 },
};
#define MOD_FIELD_XX(fname, set, val, bits, f_dec, f_hex, f_type) \
@ -154,11 +155,28 @@ struct sb_field {
} \
}
#define MOD_DEV_FIELD_XX(fname, set, val, bits, f_dec, f_hex, f_type) \
else if (strcmp(name, #fname) == 0) { \
if (set) { \
printf("SET: "#fname" "f_dec" (0x"f_hex")\n", \
(f_type)*val, (f_type)*val); \
sb->dev_item.fname = cpu_to_le##bits(*val); \
} else { \
*val = le##bits##_to_cpu(sb->dev_item.fname); \
printf("GET: "#fname" "f_dec" (0x"f_hex")\n", \
(f_type)*val, (f_type)*val); \
} \
}
#define MOD_FIELD64(fname, set, val) \
MOD_FIELD_XX(fname, set, val, 64, "%llu", "%llx", unsigned long long)
#define MOD_DEV_FIELD64(fname, set, val) \
MOD_DEV_FIELD_XX(fname, set, val, 64, "%llu", "%llx", unsigned long long)
/* Alias for u64 */
#define MOD_FIELD(fname, set, val) MOD_FIELD64(fname, set, val)
#define MOD_DEV_FIELD(fname, set, val) MOD_DEV_FIELD64(fname, set, val)
/*
* Support only GET and SET properly, ADD and SUB may work
@ -202,6 +220,7 @@ static void mod_field_by_name(struct btrfs_super_block *sb, int set, const char
MOD_FIELD8(log_root_level, set, val)
MOD_FIELD(cache_generation, set, val)
MOD_FIELD(uuid_tree_generation, set, val)
MOD_DEV_FIELD(devid, set, val)
else {
printf("ERROR: unhandled field: %s\n", name);
exit(1);
@ -260,7 +279,8 @@ static int arg_to_op_value(const char *arg, enum field_op *op, u64 *val)
return 0;
}
int main(int argc, char **argv) {
int main(int argc, char **argv)
{
int fd;
loff_t off;
int ret;