[PATCH] erofs-utils: lib: ignore xattr_types[0] when matching xattr prefixes

[Gao Xiang]

It's not the preferred prefix to target xattr names, at least.

Fixes: 2faeebb47c68 ("erofs-utils: lib: introduce prefix-aware 
erofs_setxattr()")
Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
 lib/xattr.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/lib/xattr.c b/lib/xattr.c
index 764aee3..37ce55b 100644
--- a/lib/xattr.c
+++ b/lib/xattr.c
@@ -213,7 +213,8 @@ bool erofs_xattr_prefix_matches(const char *key, unsigned 
int *index,
 
        *index = 0;
        *len = 0;
-       for (p = xattr_types; p < xattr_types + ARRAY_SIZE(xattr_types); ++p) {
+       for (p = xattr_types + 1;
+            p < xattr_types + ARRAY_SIZE(xattr_types); ++p) {
                if (p->prefix && !strncmp(p->prefix, key, p->prefix_len)) {
                        *len = p->prefix_len;
                        *index = p - xattr_types;
@@ -506,10 +507,9 @@ int erofs_setxattr(struct erofs_inode *inode, int index,
 {
        struct erofs_sb_info *sbi = inode->sbi;
        struct erofs_xattritem *item;
-       struct erofs_xattr_prefix *prefix = NULL;
+       const struct erofs_xattr_prefix *prefix = NULL;
        struct ea_type_node *tnode;
        unsigned int len[2];
-       int prefix_len;
        char *kvbuf;
 
        if (index & EROFS_XATTR_LONG_PREFIX) {
@@ -526,16 +526,16 @@ int erofs_setxattr(struct erofs_inode *inode, int index,
        if (!prefix)
                return -EINVAL;
 
-       prefix_len = prefix->prefix_len;
-       len[0] = prefix_len + strlen(name);
+       len[0] = prefix->prefix_len + strlen(name);
        len[1] = size;
 
        kvbuf = malloc(EROFS_XATTR_KVSIZE(len));
        if (!kvbuf)
                return -ENOMEM;
 
-       memcpy(kvbuf, prefix->prefix, prefix_len);
-       memcpy(kvbuf + prefix_len, name, EROFS_XATTR_KSIZE(len) - prefix_len);
+       memcpy(kvbuf, prefix->prefix, prefix->prefix_len);
+       memcpy(kvbuf + prefix->prefix_len, name,
+              EROFS_XATTR_KSIZE(len) - prefix->prefix_len);
        memcpy(kvbuf + EROFS_XATTR_KSIZE(len), value, size);
 
        item = get_xattritem(sbi, kvbuf, len);
-- 
2.43.0