[PATCH v2 4/5] dump.erofs: add -i options to dump file information of specific inode number

Gao Xiang hsiangkao at linux.alibaba.com
Tue Sep 14 23:20:16 AEST 2021


On Tue, Sep 14, 2021 at 03:44:23PM +0800, Guo Xuenan wrote:
> From: Wang Qi <mpiglet at outlook.com>
> 
> Signed-off-by: Guo Xuenan <guoxuenan at huawei.com>
> Signed-off-by: Wang Qi <mpiglet at outlook.com>

Just a rough check, it still doesn't handle hardlink, but that is fine
anyway.

I think if the first patches get into shape, we could merge them in
advance.

Also, I'd like to add a feature to get the independent file
distribution in the fiemap-likewise form, which is useful to debug some
specific compressed files (by using the patch Jianan backported before.)


Thanks,
Gao Xiang

> ---
>  dump/main.c | 161 +++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 159 insertions(+), 2 deletions(-)
> 
> diff --git a/dump/main.c b/dump/main.c
> index 0778354..233de50 100644
> --- a/dump/main.c
> +++ b/dump/main.c
> @@ -21,8 +21,10 @@
>  
>  struct dumpcfg {
>  	bool print_superblock;
> +	bool print_inode;
>  	bool print_statistic;
>  	bool print_version;
> +	u64 ino;
>  };
>  static struct dumpcfg dumpcfg;
>  
> @@ -109,8 +111,9 @@ static void usage(void)
>  	fputs("usage: [options] erofs-image\n\n"
>  		"Dump erofs layout from erofs-image, and [options] are:\n"
>  		"--help  display this help and exit.\n"
> -		"-s          print information about superblock\n"
> +		"-s      print information about superblock\n"
>  		"-S      print statistic information of the erofs-image\n"
> +		"-i #    print target # inode info\n"
>  		"-V      print the version number of dump.erofs and exit.\n",
>  		stdout);
>  }
> @@ -123,10 +126,16 @@ static void dumpfs_print_version(void)
>  static int dumpfs_parse_options_cfg(int argc, char **argv)
>  {
>  	int opt;
> +	u64 i;
>  
> -	while ((opt = getopt_long(argc, argv, "sSV",
> +	while ((opt = getopt_long(argc, argv, "i:sSV",
>  					long_options, NULL)) != -1) {
>  		switch (opt) {
> +		case 'i':
> +			i = atoll(optarg);
> +			dumpcfg.print_inode = true;
> +			dumpcfg.ino = i;
> +			break;
>  		case 's':
>  			dumpcfg.print_superblock = true;
>  			break;
> @@ -179,6 +188,151 @@ static int get_file_compressed_size(struct erofs_inode *inode,
>  	}
>  	return 0;
>  }
> +static int get_path_by_nid(erofs_nid_t nid, erofs_nid_t parent_nid,
> +		erofs_nid_t target, char *path, unsigned int pos)
> +{
> +	int err;
> +	struct erofs_inode inode = {.nid = nid};
> +	erofs_off_t offset;
> +	char buf[EROFS_BLKSIZ];
> +
> +	path[pos++] = '/';
> +	if (target == sbi.root_nid)
> +		return 0;
> +
> +	err = erofs_read_inode_from_disk(&inode);
> +	if (err) {
> +		erofs_err("read inode %lu failed", nid);
> +		return err;
> +	}
> +
> +	offset = 0;
> +	while (offset < inode.i_size) {
> +		erofs_off_t maxsize = min_t(erofs_off_t,
> +					inode.i_size - offset, EROFS_BLKSIZ);
> +		struct erofs_dirent *de = (void *)buf;
> +		struct erofs_dirent *end;
> +		unsigned int nameoff;
> +
> +		err = erofs_pread(&inode, buf, maxsize, offset);
> +		if (err)
> +			return err;
> +
> +		nameoff = le16_to_cpu(de->nameoff);
> +		if (nameoff < sizeof(struct erofs_dirent) ||
> +		    nameoff >= PAGE_SIZE) {
> +			erofs_err("invalid de[0].nameoff %u @ nid %llu",
> +				  nameoff, nid | 0ULL);
> +			return -EFSCORRUPTED;
> +		}
> +
> +		end = (void *)buf + nameoff;
> +		while (de < end) {
> +			const char *dname;
> +			unsigned int dname_len;
> +
> +			nameoff = le16_to_cpu(de->nameoff);
> +			dname = (char *)buf + nameoff;
> +			if (de + 1 >= end)
> +				dname_len = strnlen(dname, maxsize - nameoff);
> +			else
> +				dname_len = le16_to_cpu(de[1].nameoff)
> +					- nameoff;
> +
> +			/* a corrupted entry is found */
> +			if (nameoff + dname_len > maxsize ||
> +			    dname_len > EROFS_NAME_LEN) {
> +				erofs_err("bogus dirent @ nid %llu",
> +						le64_to_cpu(de->nid) | 0ULL);
> +				DBG_BUGON(1);
> +				return -EFSCORRUPTED;
> +			}
> +
> +			if (de->nid == target) {
> +				memcpy(path + pos, dname, dname_len);
> +				return 0;
> +			}
> +
> +			if (de->file_type == EROFS_FT_DIR &&
> +					de->nid != parent_nid &&
> +					de->nid != nid) {
> +				memcpy(path + pos, dname, dname_len);
> +				err = get_path_by_nid(de->nid, nid,
> +						target, path, pos + dname_len);
> +				if (!err)
> +					return 0;
> +				memset(path + pos, 0, dname_len);
> +			}
> +			++de;
> +		}
> +		offset += maxsize;
> +	}
> +	return -1;
> +}
> +
> +static void dumpfs_print_inode(void)
> +{
> +	int err;
> +	erofs_off_t size;
> +	u16 access_mode;
> +	time_t t;
> +	erofs_nid_t nid = dumpcfg.ino;
> +	struct erofs_inode inode = {.nid = nid};
> +	char path[PATH_MAX + 1] = {0};
> +	char access_mode_str[] = "rwxrwxrwx";
> +
> +	err = erofs_read_inode_from_disk(&inode);
> +	if (err) {
> +		erofs_err("read inode %lu from disk failed", nid);
> +		return;
> +	}
> +
> +	err = get_file_compressed_size(&inode, &size);
> +	if (err) {
> +		erofs_err("get file size failed\n");
> +		return;
> +	}
> +
> +	fprintf(stdout, "Inode %lu info:\n", dumpcfg.ino);
> +	err = get_path_by_nid(sbi.root_nid, sbi.root_nid, nid, path, 0);
> +
> +	fprintf(stdout, "File path:            %s\n",
> +			!err ? path : "path not found");
> +	fprintf(stdout, "File nid:             %lu\n", inode.nid);
> +	fprintf(stdout, "File inode core size: %d\n", inode.inode_isize);
> +	fprintf(stdout, "File original size:   %lu\n", inode.i_size);
> +	fprintf(stdout,	"File on-disk size:    %lu\n", size);
> +	fprintf(stdout, "File compress rate:   %.2f%%\n",
> +			(double)(100 * size) / (double)(inode.i_size));
> +	fprintf(stdout, "File extent size:     %u\n", inode.extent_isize);
> +	fprintf(stdout,	"File xattr size:      %u\n", inode.xattr_isize);
> +	fprintf(stdout, "File type:            ");
> +	switch (inode.i_mode & S_IFMT) {
> +	case S_IFBLK:  fprintf(stdout, "block device\n");     break;
> +	case S_IFCHR:  fprintf(stdout, "character device\n"); break;
> +	case S_IFDIR:  fprintf(stdout, "directory\n");        break;
> +	case S_IFIFO:  fprintf(stdout, "FIFO/pipe\n");        break;
> +	case S_IFLNK:  fprintf(stdout, "symlink\n");          break;
> +	case S_IFREG:  fprintf(stdout, "regular file\n");     break;
> +	case S_IFSOCK: fprintf(stdout, "socket\n");           break;
> +	default:       fprintf(stdout, "unknown?\n");         break;
> +	}
> +
> +	access_mode = inode.i_mode & 0777;
> +	t = inode.i_ctime;
> +	for (int i = 8; i >= 0; i--)
> +		if (((access_mode >> i) & 1) == 0)
> +			access_mode_str[8 - i] = '-';
> +	fprintf(stdout, "File access:          %04o/%s\n",
> +			access_mode, access_mode_str);
> +	fprintf(stdout, "File uid:             %u\n", inode.i_uid);
> +	fprintf(stdout, "File gid:             %u\n", inode.i_gid);
> +	fprintf(stdout, "File datalayout:      %d\n", inode.datalayout);
> +	fprintf(stdout,	"File nlink:           %u\n", inode.i_nlink);
> +	fprintf(stdout, "File create time:     %s", ctime(&t));
> +	fprintf(stdout, "File access time:     %s", ctime(&t));
> +	fprintf(stdout, "File modify time:     %s", ctime(&t));
> +}
>  
>  static int get_file_type(const char *filename)
>  {
> @@ -514,6 +668,9 @@ int main(int argc, char **argv)
>  
>  	if (dumpcfg.print_statistic)
>  		dumpfs_print_statistic();
> +
> +	if (dumpcfg.print_inode)
> +		dumpfs_print_inode();
>  out:
>  	if (cfg.c_img_path)
>  		free(cfg.c_img_path);
> -- 
> 2.25.4


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