[PATCH v8 2/2] erofs-utils: fsck: introduce exporting xattrs

Hongzhen Luo hongzhen at linux.alibaba.com
Fri Sep 13 16:21:14 AEST 2024


On 2024/9/13 14:13, Gao Xiang wrote:
>
>
> On 2024/9/12 21:11, 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>
>> ---
>> v8: The code has been adjusted to look better.
>> v7: 
>> https://lore.kernel.org/all/20240906095853.3167228-2-hongzhen@linux.alibaba.com/
>> v6: 
>> https://lore.kernel.org/all/20240906083849.3090392-2-hongzhen@linux.alibaba.com/
>> v5: 
>> https://lore.kernel.org/all/20240906022206.2725584-1-hongzhen@linux.alibaba.com/
>> v4: 
>> https://lore.kernel.org/all/20240905113723.1937634-1-hongzhen@linux.alibaba.com/
>> 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      | 107 +++++++++++++++++++++++++++++++++++++++++++++--
>>   man/fsck.erofs.1 |   3 ++
>>   2 files changed, 106 insertions(+), 4 deletions(-)
>>
>> diff --git a/fsck/main.c b/fsck/main.c
>> index 28f1e7e..af0c01f 100644
>> --- a/fsck/main.c
>> +++ b/fsck/main.c
>> @@ -9,10 +9,12 @@
>>   #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"
>>   #include "erofs/dir.h"
>> +#include "erofs/xattr.h"
>>   #include "../lib/compressor.h"
>>     static int erofsfsck_check_inode(erofs_nid_t pnid, erofs_nid_t nid);
>> @@ -31,6 +33,7 @@ struct erofsfsck_cfg {
>>       bool overwrite;
>>       bool preserve_owner;
>>       bool preserve_perms;
>> +    bool dump_xattrs;
>>   };
>>   static struct erofsfsck_cfg fsckcfg;
>>   @@ -48,6 +51,8 @@ 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 +103,7 @@ 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"
>> +        " --[no-]xattrs          whether to dump extended attributes 
>> (default off)\n"
>>           "\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 +423,84 @@ out:
>>       return ret;
>>   }
>>   +static int erofsfsck_dump_xattrs(struct erofs_inode *inode)
>> +{
>> +    static bool ignore_xattrs = false;
>> +    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 != kllen) {
>> +        erofs_err("failed to list xattrs @ nid %llu",
>> +              inode->nid | 0ULL);
>> +        ret = -EINVAL;
>> +        goto out;
>> +    }
>> +    ret = 0;
>> +    for (key = keylst; key < keylst + kllen; key += strlen(key) + 1) {
>> +        unsigned int index, len;
>> +        void *value = NULL;
>> +        size_t size = 0;
>> +
>> +        ret = erofs_getxattr(inode, key, NULL, 0);
>> +        if (ret <= 0)
>> +            break;
>> +        size = ret;
>> +        value = malloc(size);
>> +        if (!value) {
>> +            ret = -ENOMEM;
>> +            break;
>> +        }
>> +        ret = erofs_getxattr(inode, key, value, size);
>> +        if (ret < 0) {
>> +            erofs_err("failed to get xattr `%s` @ nid %llu, because 
>> of `%s`", key,
>> +                  inode->nid | 0ULL, erofs_strerror(ret));
>> +            free(value);
>> +            break;
>> +        }
>> +        if (fsckcfg.extract_path)
>> +            ret = lsetxattr(fsckcfg.extract_path, key, value, size,
>> +                    0);
>> +        else
>> +            ret = 0;
>> +        free(value);
>> +        if (ret == -EPERM && !fsckcfg.superuser) {
>> +            if (__erofs_unlikely(!erofs_xattr_prefix_matches(key,
>> +                    &index, &len))) {
>> +                erofs_err("failed to match the prefix of `%s` @ nid 
>> %llu",
>> +                      key, inode->nid | 0ULL);
>> +                ret = -EINVAL;
>> +                break;
>> +            }
>> +            if (index != EROFS_XATTR_INDEX_USER) {
>> +                if (!ignore_xattrs) {
>> +                    erofs_warn("ignored xattr `%s` @ nid %llu, due 
>> to non-superuser",
>> +                           key, inode->nid | 0ULL);
>> +                    ignore_xattrs = true;
>> +                }
>> +                ret = 0;
>> +                continue;
>> +            }
>> +
>> +        }
>> +        if (ret) {
>> +            erofs_err("failed to set xattr `%s` @ nid %llu because 
>> of `%s`",
>> +                  key, inode->nid | 0ULL, erofs_strerror(ret));
>> +            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 +990,23 @@ 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) {
>
> It should be `!(fsckcfg.check_decomp && fsckcfg.dump_xattr)`?
>
Yes, I will fix this in the next patch.
>> +        /* 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 +1053,7 @@ int main(int argc, char *argv[])
>>       fsckcfg.overwrite = false;
>>       fsckcfg.preserve_owner = fsckcfg.superuser;
>>       fsckcfg.preserve_perms = fsckcfg.superuser;
>> +    fsckcfg.dump_xattrs = false;
>>         err = erofsfsck_parse_options_cfg(argc, argv);
>>       if (err) {
>> diff --git a/man/fsck.erofs.1 b/man/fsck.erofs.1
>> index 393ae9e..fc862e2 100644
>> --- a/man/fsck.erofs.1
>> +++ b/man/fsck.erofs.1
>> @@ -27,6 +27,9 @@ You may give multiple
>>   .B --device
>>   options in the correct order.
>>   .TP
>> +.BI "--[no-]xattrs"
>> +Whether to dump extended attributes (default off).
>
> Why is it placed here? (it should be located according
> to alphabetic order)
>
> Also better to be
> `Whether to dump extended attributes during extraction (default off)`
>
Yes. I will send a new version soon.

Thanks,

Hongzhen Luo

> Thanks,
> Gao Xiang


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