On 2023/6/1 10:43, Jingbo Xu wrote:
There's a callback styled xattr parser, i.e. xattr_foreach(), which is
shared among listxattr and getxattr. Convert it to two separate xattr
parsers for listxattr and getxattr.
Signed-off-by: Jingbo Xu <[email protected]>
---
...
+static int erofs_xattr_body(struct erofs_xattr_iter *it,
+ unsigned int len, bool copy)
It might be better to call it as "erofs_xattr_handle_string".
{
- unsigned int base_index = entry->e_name_index;
- unsigned int prefix_len, infix_len = 0;
+ unsigned int slice, processed = 0;
+ void *buf;
+ int err;
+
+ while (processed < len) {
+ err = erofs_xattr_iter_fixup(it, true);
+ if (err)
+ return err;
+
+ buf = it->kaddr + it->ofs;
+ slice = min_t(unsigned int, it->sb->s_blocksize - it->ofs,
+ len - processed);
+ if (copy) {
+ memcpy(it->buffer + it->buffer_ofs, buf, slice);
+ it->buffer_ofs += slice;
+ } else if (memcmp(it->name.name + it->infix_len + processed,
+ buf, slice)) {
+ return -ENOATTR;
+ }
+ it->ofs += slice;
+ processed += slice;
+ }
+ return 0;
+}
+
+/*
+ * Wen returning 0 or ENOATTR, erofs_[list|get]xattr_foreach() will end up
+ * with `ofs' pointing to the next xattr item rather than an arbitrary
position.
+ */
+static int erofs_listxattr_foreach(struct erofs_xattr_iter *it)
+{
+ struct erofs_xattr_entry entry;
+ unsigned int base_index, prefix_len, infix_len = 0;
const char *prefix, *infix = NULL;
+ int err;
- if (entry->e_name_index & EROFS_XATTR_LONG_PREFIX) {
+ /* 1. handle xattr entry */
+ entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs);
+ it->ofs += sizeof(struct erofs_xattr_entry);
+ base_index = entry.e_name_index;
+
+ if (entry.e_name_index & EROFS_XATTR_LONG_PREFIX) {
struct erofs_sb_info *sbi = EROFS_SB(it->sb);
struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes +
- (entry->e_name_index & EROFS_XATTR_LONG_PREFIX_MASK);
+ (entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK);
if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count)
- return 1;
+ goto out;
infix = pf->prefix->infix;
infix_len = pf->infix_len;
base_index = pf->prefix->base_index;
@@ -392,53 +252,99 @@ static int xattr_entrylist(struct erofs_xattr_iter *it,
prefix = erofs_xattr_prefix(base_index, it->dentry);
if (!prefix)
- return 1;
+ goto out;
prefix_len = strlen(prefix);
if (!it->buffer) {
- it->buffer_ofs += prefix_len + infix_len +
- entry->e_name_len + 1;
- return 1;
+ it->buffer_ofs += prefix_len + infix_len + entry.e_name_len + 1;
+ goto out;
}
if (it->buffer_ofs + prefix_len + infix_len +
- + entry->e_name_len + 1 > it->buffer_size)
+ entry.e_name_len + 1 > it->buffer_size)
return -ERANGE;
memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len);
memcpy(it->buffer + it->buffer_ofs + prefix_len, infix, infix_len);
it->buffer_ofs += prefix_len + infix_len;
- return 0;
-}
-static int xattr_namelist(struct erofs_xattr_iter *it,
- unsigned int processed, char *buf, unsigned int len)
-{
- memcpy(it->buffer + it->buffer_ofs, buf, len);
- it->buffer_ofs += len;
+ /* 2. handle xattr name (err can't be ENOATTR) */
+ err = erofs_xattr_body(it, entry.e_name_len, true);
+ if (err)
+ return err;
+
+ it->buffer[it->buffer_ofs++] = '\0';
+ it->ofs += le16_to_cpu(entry.e_value_size);
+ it->ofs = EROFS_XATTR_ALIGN(it->ofs);
+ return 0;
+out:
+ it->ofs = it->next_ofs;
return 0;
}
-static int xattr_skipvalue(struct erofs_xattr_iter *it,
- unsigned int value_sz)
+static int erofs_getxattr_foreach(struct erofs_xattr_iter *it)
{
- it->buffer[it->buffer_ofs++] = '\0';
- return 1;
-}
+ struct erofs_xattr_entry entry;
+ unsigned int value_sz;
+ int err;
-static const struct xattr_iter_handlers list_xattr_handlers = {
- .entry = xattr_entrylist,
- .name = xattr_namelist,
- .alloc_buffer = xattr_skipvalue,
- .value = NULL
-};
+ /* 1. handle xattr entry */
+ entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs);
+ it->ofs += sizeof(struct erofs_xattr_entry);
+ value_sz = le16_to_cpu(entry.e_value_size);
+
+ err = -ENOATTR;
+ /* should also match the infix for long name prefixes */
+ if (entry.e_name_index & EROFS_XATTR_LONG_PREFIX) {
+ struct erofs_sb_info *sbi = EROFS_SB(it->sb);
+ struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes +
+ (entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK);
+
+ if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count)
+ goto out;
+
+ if (it->index != pf->prefix->base_index ||
+ it->name.len != entry.e_name_len + pf->infix_len)
+ goto out;
+
+ if (memcmp(it->name.name, pf->prefix->infix, pf->infix_len))
+ goto out;
+
+ it->infix_len = pf->infix_len;
+ } else {
+ if (it->index != entry.e_name_index ||
+ it->name.len != entry.e_name_len)
+ goto out;
please use "} else if {" here
+ it->infix_len = 0;
+ }
+
Thanks,
Gao Xiang
