erofs-utils: fsck: introduce exporting xattrs

Currently `fsck --extract` does not support exporting
extended attributes. This patch adds the `--xattrs` option
to dump extended attributes and the `--no-xattrs` option to
omit them (the default behavior).

Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240913072100.577753-2-hongzhen@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

diff --git a/configure.ac b/configure.ac
index 945e254cf76c25ca33100485c8143a69fe5717ef..9c1657bf1d14b783a391e83b5bb34e751e26c337 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -260,6 +260,7 @@ AC_CHECK_FUNCS(m4_flatten([
        gettimeofday
        lgetxattr
        llistxattr
+       lsetxattr
        memset
        realpath
        lseek64

diff --git a/fsck/main.c b/fsck/main.c
index 89d87fbb2aa7926afda496e3c2deba9071bc8958..f20b767ccf335801fc48758511c79206ef7d9c88 100644 (file)
--- 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 +423,95 @@ 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) {
+                       DBG_BUGON(1);
+                       erofs_err("failed to get xattr value size of `%s` @ nid %llu",
+                                 key, inode->nid | 0ULL);
+                       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)
+#ifdef HAVE_LSETXATTR
+                       ret = lsetxattr(fsckcfg.extract_path, key, value, size,
+                                       0);
+#elif defined(__APPLE__)
+                       ret = setxattr(fsckcfg.extract_path, key, value, size,
+                                      0, XATTR_NOFOLLOW);
+#else
+                       ret = -EOPNOTSUPP;
+#endif
+               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 +1001,23 @@ 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 && fsckcfg.dump_xattrs)) {
+               /* 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 +1064,7 @@ 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 393ae9e524b45a41cbf294c8764db33adfbd221c..af0e6abc3344163422ba747123a1ad90464a9206 100644 (file)
--- a/man/fsck.erofs.1
+++ b/man/fsck.erofs.1
@@ -34,6 +34,9 @@ take a long time depending on the image size.
 
 Optionally extract contents of the \fIIMAGE\fR to \fIdirectory\fR.
 .TP
+.BI "--[no-]xattrs"
+Whether to dump extended attributes during extraction (default off).
+.TP
 \fB\-h\fR, \fB\-\-help\fR
 Display help string and exit.
 .TP