Adding code for superblock checksum calculation.
This patch adds following things:
1)Handle suboptions('-o') to mkfs utility.
2)Add superblock checksum calculation(-o sb_cksum) as suboption.
3)Calculate superblock checksum if feature is enabled.
Signed-off-by: Pratik Shinde <[email protected]>
---
include/erofs/config.h | 1 +
include/erofs_fs.h | 40 +++++++++++++++++++++----------------
mkfs/main.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 76 insertions(+), 18 deletions(-)
diff --git a/include/erofs/config.h b/include/erofs/config.h
index 05fe6b2..40cd466 100644
--- a/include/erofs/config.h
+++ b/include/erofs/config.h
@@ -22,6 +22,7 @@ struct erofs_configure {
char *c_src_path;
char *c_compr_alg_master;
int c_compr_level_master;
+ int c_feature_flags;
};
extern struct erofs_configure cfg;
diff --git a/include/erofs_fs.h b/include/erofs_fs.h
index 601b477..c9ef057 100644
--- a/include/erofs_fs.h
+++ b/include/erofs_fs.h
@@ -20,25 +20,31 @@
#define EROFS_REQUIREMENT_LZ4_0PADDING 0x00000001
#define EROFS_ALL_REQUIREMENTS EROFS_REQUIREMENT_LZ4_0PADDING
+/*
+ * feature definations.
+ */
+#define EROFS_FEATURE_SB_CHKSUM 0x0001
+
+#define EROFS_HAS_COMPAT_FEATURE(super,mask) \
+ ( le32_to_cpu((super)->features) & (mask) )
+
struct erofs_super_block {
/* 0 */__le32 magic; /* in the little endian */
-/* 4 */__le32 checksum; /* crc32c(super_block) */
-/* 8 */__le32 features; /* (aka. feature_compat) */
-/* 12 */__u8 blkszbits; /* support block_size == PAGE_SIZE only */
-/* 13 */__u8 reserved;
-
-/* 14 */__le16 root_nid;
-/* 16 */__le64 inos; /* total valid ino # (== f_files - f_favail) */
-
-/* 24 */__le64 build_time; /* inode v1 time derivation */
-/* 32 */__le32 build_time_nsec;
-/* 36 */__le32 blocks; /* used for statfs */
-/* 40 */__le32 meta_blkaddr;
-/* 44 */__le32 xattr_blkaddr;
-/* 48 */__u8 uuid[16]; /* 128-bit uuid for volume */
-/* 64 */__u8 volume_name[16]; /* volume name */
-/* 80 */__le32 requirements; /* (aka. feature_incompat) */
-
+/* 4 */__le32 features; /* (aka. feature_compat) */
+/* 8 */__u8 blkszbits; /* support block_size == PAGE_SIZE only */
+/* 9 */__u8 reserved;
+
+/* 10 */__le16 root_nid;
+/* 12 */__le64 inos; /* total valid ino # (== f_files - f_favail) */
+/* 20 */__le64 build_time; /* inode v1 time derivation */
+/* 28 */__le32 build_time_nsec;
+/* 32 */__le32 blocks; /* used for statfs */
+/* 36 */__le32 meta_blkaddr;
+/* 40 */__le32 xattr_blkaddr;
+/* 44 */__u8 uuid[16]; /* 128-bit uuid for volume */
+/* 60 */__u8 volume_name[16]; /* volume name */
+/* 76 */__le32 requirements; /* (aka. feature_incompat) */
+/* 80 */__le32 checksum; /* crc32c(super_block) */
/* 84 */__u8 reserved2[44];
} __packed; /* 128 bytes */
diff --git a/mkfs/main.c b/mkfs/main.c
index f127fe1..26e14a3 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -13,12 +13,14 @@
#include <limits.h>
#include <libgen.h>
#include <sys/stat.h>
+#include <zlib.h>
#include "erofs/config.h"
#include "erofs/print.h"
#include "erofs/cache.h"
#include "erofs/inode.h"
#include "erofs/io.h"
#include "erofs/compress.h"
+#include "erofs/defs.h"
#define EROFS_SUPER_END (EROFS_SUPER_OFFSET + sizeof(struct erofs_super_block))
@@ -31,6 +33,28 @@ static void usage(void)
fprintf(stderr, " -EX[,...] X=extended options\n");
}
+char *feature_opts[] = {
+ "sb_cksum", NULL
+};
+#define O_SB_CKSUM 0
+
+static int parse_feature_subopts(char *opts)
+{
+ char *arg;
+
+ while (*opts != '\0') {
+ switch(getsubopt(&opts, feature_opts, &arg)) {
+ case O_SB_CKSUM:
+ cfg.c_feature_flags |= EROFS_FEATURE_SB_CHKSUM;
+ break;
+ default:
+ erofs_err("incorrect suboption");
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
static int parse_extended_opts(const char *opts)
{
#define MATCH_EXTENTED_OPT(opt, token, keylen) \
@@ -79,7 +103,7 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
{
int opt, i;
- while ((opt = getopt(argc, argv, "d:z:E:")) != -1) {
+ while ((opt = getopt(argc, argv, "d:z:E:o:")) != -1) {
switch (opt) {
case 'z':
if (!optarg) {
@@ -113,6 +137,12 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
return opt;
break;
+ case 'o':
+ opt = parse_feature_subopts(optarg);
+ if (opt)
+ return opt;
+ break;
+
default: /* '?' */
return -EINVAL;
}
@@ -144,6 +174,21 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
return 0;
}
+u32 erofs_superblock_checksum(struct erofs_super_block *sb)
+{
+ int offset;
+ u32 crc;
+
+ offset = offsetof(struct erofs_super_block, checksum);
+ if (offset < 0 || offset > sizeof(struct erofs_super_block)) {
+ erofs_err("Invalid offset of checksum field: %d", offset);
+ return -1;
+ }
+ crc = crc32(~0, (const unsigned char *)sb,(size_t)offset);
+ erofs_dump("superblock checksum: 0x%x\n", crc);
+ return 0;
+}
+
int erofs_mkfs_update_super_block(struct erofs_buffer_head *bh,
erofs_nid_t root_nid)
{
@@ -155,6 +200,7 @@ int erofs_mkfs_update_super_block(struct erofs_buffer_head
*bh,
.meta_blkaddr = sbi.meta_blkaddr,
.xattr_blkaddr = 0,
.requirements = cpu_to_le32(sbi.requirements),
+ .features = cpu_to_le32(cfg.c_feature_flags),
};
const unsigned int sb_blksize =
round_up(EROFS_SUPER_END, EROFS_BLKSIZ);
@@ -169,6 +215,11 @@ int erofs_mkfs_update_super_block(struct erofs_buffer_head
*bh,
sb.blocks = cpu_to_le32(erofs_mapbh(NULL, true));
sb.root_nid = cpu_to_le16(root_nid);
+ if (EROFS_HAS_COMPAT_FEATURE(&sb, EROFS_FEATURE_SB_CHKSUM)) {
+ u32 crc = erofs_superblock_checksum(&sb);
+ sb.checksum = cpu_to_le32(crc);
+ }
+
buf = calloc(sb_blksize, 1);
if (!buf) {
erofs_err("Failed to allocate memory for sb: %s",
--
2.9.3
