[External Mail][PATCH v4] erofs-utils: fsck: introduce exporting xattrs

[Huang Jianan]

On 2024/9/5 19:37, Hongzhen Luo wrote:
> 
> The current `fsck --extract` does not support exporting the extended
> attributes of files. This patch adds `--xattrs` option to dump the
> extended attributes, as well as the `--no-xattrs` option to not dump
> the extended attributes.
> 
> Signed-off-by: Hongzhen Luo <hongzhen at linux.alibaba.com>
> ---
> v4: Optimize the error messages and code.
> v3: https://lore.kernel.org/all/20240903113729.3539578-1-hongzhen@linux.alibaba.com/
> v2: https://lore.kernel.org/all/20240903085643.3393012-1-hongzhen@linux.alibaba.com/
> v1: https://lore.kernel.org/all/20240903073517.3311407-1-hongzhen@linux.alibaba.com/
> ---
>   fsck/main.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++---
>   1 file changed, 79 insertions(+), 4 deletions(-)
> 
> diff --git a/fsck/main.c b/fsck/main.c
> index 28f1e7e..183665c 100644
> --- a/fsck/main.c
> +++ b/fsck/main.c
> @@ -9,6 +9,7 @@
>   #include <utime.h>
>   #include <unistd.h>
>   #include <sys/stat.h>
> +#include <sys/xattr.h>
>   #include "erofs/print.h"
>   #include "erofs/compress.h"
>   #include "erofs/decompress.h"
> @@ -31,6 +32,7 @@ struct erofsfsck_cfg {
>          bool overwrite;
>          bool preserve_owner;
>          bool preserve_perms;
> +       bool dump_xattrs;
>   };
>   static struct erofsfsck_cfg fsckcfg;
> 
> @@ -48,6 +50,8 @@ static struct option long_options[] = {
>          {"no-preserve-owner", no_argument, 0, 10},
>          {"no-preserve-perms", no_argument, 0, 11},
>          {"offset", required_argument, 0, 12},
> +       {"xattrs", no_argument, 0, 13},
> +       {"no-xattrs", no_argument, 0, 14},
>          {0, 0, 0, 0},
>   };
> 
> @@ -98,6 +102,8 @@ static void usage(int argc, char **argv)
>                  " --extract[=X]          check if all files are well encoded, optionally\n"
>                  "                        extract to X\n"
>                  " --offset=#             skip # bytes at the beginning of IMAGE\n"
> +               " --xattrs               dump extended attributes (default)\n"
> +               " --no-xattrs            do not dump extended attributes\n"

How about:

" --[no-]xattrs  whether to dump extended attributes (default on)\n"

To keep the same style as the other switch options.

Thanks,
Jianan

>                  "\n"
>                  " -a, -A, -y             no-op, for compatibility with fsck of other filesystems\n"
>                  "\n"
> @@ -225,6 +231,12 @@ static int erofsfsck_parse_options_cfg(int argc, char **argv)
>                                  return -EINVAL;
>                          }
>                          break;
> +               case 13:
> +                       fsckcfg.dump_xattrs = true;
> +                       break;
> +               case 14:
> +                       fsckcfg.dump_xattrs = false;
> +                       break;
>                  default:
>                          return -EINVAL;
>                  }
> @@ -411,6 +423,60 @@ out:
>          return ret;
>   }
> 
> +static int erofsfsck_dump_xattrs(struct erofs_inode *inode)
> +{
> +       char *keylst, *key;
> +       ssize_t kllen;
> +       int ret;
> +
> +       kllen = erofs_listxattr(inode, NULL, 0);
> +       if (kllen <= 0)
> +               return kllen;
> +       keylst = malloc(kllen);
> +       if (!keylst)
> +               return -ENOMEM;
> +       ret = erofs_listxattr(inode, keylst, kllen);
> +       if (ret < 0)
> +               goto out;
> +       for (key = keylst; key < keylst + kllen; key += strlen(key) + 1) {
> +               void *value = NULL;
> +               size_t size = 0;
> +
> +               ret = erofs_getxattr(inode, key, NULL, 0);
> +               if (ret < 0)
> +                       break;
> +               if (ret) {
> +                       size = ret;
> +                       value = malloc(size);
> +                       if (!value) {
> +                               ret = -ENOMEM;
> +                               break;
> +                       }
> +                       ret = erofs_getxattr(inode, key, value, size);
> +                       if (ret < 0) {
> +                               erofs_err("fail to get xattr %s @ nid %llu",
> +                                         key, inode->nid | 0ULL);
> +                               free(value);
> +                               break;
> +                       }
> +                       if (fsckcfg.extract_path)
> +                               ret = setxattr(fsckcfg.extract_path, key, value,
> +                                              size, 0);
> +                       else
> +                               ret = 0;
> +                       free(value);
> +                       if (ret) {
> +                               erofs_err("fail to set xattr %s @ nid %llu",
> +                                         key, inode->nid | 0ULL);
> +                               break;
> +                       }
> +               }
> +       }
> +out:
> +       free(keylst);
> +       return ret;
> +}
> +
>   static int erofs_verify_inode_data(struct erofs_inode *inode, int outfd)
>   {
>          struct erofs_map_blocks map = {
> @@ -900,15 +966,23 @@ static int erofsfsck_check_inode(erofs_nid_t pnid, erofs_nid_t nid)
>                  goto out;
>          }
> 
> -       /* verify xattr field */
> -       ret = erofs_verify_xattr(&inode);
> -       if (ret)
> -               goto out;
> +       if (!fsckcfg.check_decomp) {
> +               /* verify xattr field */
> +               ret = erofs_verify_xattr(&inode);
> +               if (ret)
> +                       goto out;
> +       }
> 
>          ret = erofsfsck_extract_inode(&inode);
>          if (ret && ret != -ECANCELED)
>                  goto out;
> 
> +       if (fsckcfg.check_decomp && fsckcfg.dump_xattrs) {
> +               ret = erofsfsck_dump_xattrs(&inode);
> +               if (ret)
> +                       return ret;
> +       }
> +
>          /* XXXX: the dir depth should be restricted in order to avoid loops */
>          if (S_ISDIR(inode.i_mode)) {
>                  struct erofs_dir_context ctx = {
> @@ -955,6 +1029,7 @@ int main(int argc, char *argv[])
>          fsckcfg.overwrite = false;
>          fsckcfg.preserve_owner = fsckcfg.superuser;
>          fsckcfg.preserve_perms = fsckcfg.superuser;
> +       fsckcfg.dump_xattrs = true;
> 
>          err = erofsfsck_parse_options_cfg(argc, argv);
>          if (err) {
> --
> 2.43.5
>