[RFC PATCH 3/3] erofs-utils: fuse: support get/list xattr
Sheng Yong
shengyong at oppo.com
Thu Aug 4 00:22:23 AEST 2022
Add new options get and list to xattr iteration operations to
support getxattr and listxattr.
Signed-off-by: Sheng Yong <shengyong at oppo.com>
---
fsck/main.c | 2 +
fuse/main.c | 135 ++++++++++++++++++++++++++++++++++++++++++
include/erofs/xattr.h | 8 +++
lib/xattr.c | 26 ++++++--
4 files changed, 167 insertions(+), 4 deletions(-)
diff --git a/fsck/main.c b/fsck/main.c
index 237ccc1..ceaab3d 100644
--- a/fsck/main.c
+++ b/fsck/main.c
@@ -291,6 +291,8 @@ static int erofs_verify_xattr_entry(const struct erofs_xattr_entry *entry)
struct xattr_iter_ops erofs_verify_xattr_ops = {
.verify = erofs_verify_xattr_entry,
+ .list = NULL,
+ .get = NULL,
};
static int erofs_verify_xattr(struct erofs_inode *inode)
diff --git a/fuse/main.c b/fuse/main.c
index 345bcb5..7997234 100644
--- a/fuse/main.c
+++ b/fuse/main.c
@@ -14,6 +14,7 @@
#include "erofs/io.h"
#include "erofs/dir.h"
#include "erofs/inode.h"
+#include "erofs/xattr.h"
struct erofsfuse_dir_context {
struct erofs_dir_context ctx;
@@ -142,6 +143,138 @@ static int erofsfuse_readlink(const char *path, char *buffer, size_t size)
return 0;
}
+struct listxattr_iter {
+ char *buffer;
+ size_t size;
+ unsigned int ofs;
+};
+
+static int list_one_xattr(const struct erofs_xattr_entry *entry, void *data)
+{
+ struct listxattr_iter *it = (struct listxattr_iter *)data;
+ const char *prefix = xattr_types[entry->e_name_index].prefix;
+ unsigned int prefix_len = xattr_types[entry->e_name_index].prefix_len;
+ int i;
+
+ /* if size is 0, return the total size without copying data */
+ if (it->size == 0) {
+ it->ofs += prefix_len + entry->e_name_len + 1;
+ return it->ofs;
+ }
+
+ if (it->ofs + prefix_len + entry->e_name_len + 1 > it->size)
+ return -ERANGE;
+
+ switch (entry->e_name_index) {
+ case EROFS_XATTR_INDEX_USER:
+ case EROFS_XATTR_INDEX_TRUSTED:
+ case EROFS_XATTR_INDEX_SECURITY:
+ memcpy(it->buffer + it->ofs, prefix, prefix_len);
+ it->ofs += prefix_len;
+ for (i = 0; i < entry->e_name_len; i++, it->ofs++)
+ it->buffer[it->ofs] = entry->e_name[i];
+ it->buffer[it->ofs++] = '\0';
+ break;
+ case EROFS_XATTR_INDEX_POSIX_ACL_ACCESS:
+ case EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT:
+ memcpy(it->buffer + it->ofs, prefix, prefix_len);
+ it->ofs += prefix_len;
+ it->buffer[it->ofs++] = '\0';
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return it->ofs;
+}
+
+struct xattr_iter_ops erofs_listxattr_ops = {
+ .verify = NULL,
+ .list = list_one_xattr,
+ .get = NULL,
+};
+
+static int erofsfuse_listxattr(const char *path, char *list, size_t size)
+{
+ struct erofs_inode vi = {};
+ struct listxattr_iter it = {
+ .buffer = list,
+ .size = size,
+ .ofs = 0,
+ };
+
+ erofs_dbg("listxattr(%s) size %zu", path, size);
+ if (erofs_ilookup(path, &vi))
+ return -ENOENT;
+
+ return erofs_xattr_foreach(&vi, &erofs_listxattr_ops, &it);
+}
+
+struct getxattr_iter {
+ const char *name;
+ char *buffer;
+ size_t size;
+};
+
+static int get_one_xattr(const struct erofs_xattr_entry *entry, void *data)
+{
+ struct getxattr_iter *it = (struct getxattr_iter *)data;
+ const char *prefix = xattr_types[entry->e_name_index].prefix;
+ int prefix_len = xattr_types[entry->e_name_index].prefix_len;
+ int name_len, val_len;
+
+ name_len = entry->e_name_len;
+ if (strlen(it->name) != prefix_len + name_len ||
+ strncmp(it->name, prefix, prefix_len) ||
+ strncmp(it->name + prefix_len, entry->e_name, name_len))
+ /* not match */
+ return -ENODATA;
+
+ val_len = le16_to_cpu(entry->e_value_size);
+ if (it->size == 0)
+ return val_len;
+ if (val_len > it->size)
+ return -ERANGE;
+
+ switch (entry->e_name_index) {
+ case EROFS_XATTR_INDEX_USER:
+ case EROFS_XATTR_INDEX_POSIX_ACL_ACCESS:
+ case EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT:
+ case EROFS_XATTR_INDEX_TRUSTED:
+ case EROFS_XATTR_INDEX_SECURITY:
+ memcpy(it->buffer, entry->e_name + name_len, val_len);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* found */
+ return val_len;
+}
+
+struct xattr_iter_ops erofs_getxattr_ops = {
+ .verify = NULL,
+ .list = NULL,
+ .get = get_one_xattr,
+};
+
+static int erofsfuse_getxattr(const char *path, const char *name,
+ char *value, size_t size)
+{
+ struct erofs_inode vi = {};
+ struct getxattr_iter it = {
+ .name = name,
+ .buffer = value,
+ .size = size,
+ };
+
+ erofs_dbg("getxattr(%s) name %s size %zu", path, name, size);
+ if (erofs_ilookup(path, &vi))
+ return -ENOENT;
+
+ return erofs_xattr_foreach(&vi, &erofs_getxattr_ops, &it);
+}
+
static struct fuse_operations erofs_ops = {
.readlink = erofsfuse_readlink,
.getattr = erofsfuse_getattr,
@@ -149,6 +282,8 @@ static struct fuse_operations erofs_ops = {
.open = erofsfuse_open,
.read = erofsfuse_read,
.init = erofsfuse_init,
+ .listxattr = erofsfuse_listxattr,
+ .getxattr = erofsfuse_getxattr,
};
static struct options {
diff --git a/include/erofs/xattr.h b/include/erofs/xattr.h
index c592d47..eea3a2a 100644
--- a/include/erofs/xattr.h
+++ b/include/erofs/xattr.h
@@ -45,8 +45,16 @@ extern "C"
#define XATTR_NAME_POSIX_ACL_DEFAULT "system.posix_acl_default"
#endif
+struct xattr_prefix {
+ const char *prefix;
+ u16 prefix_len;
+};
+extern struct xattr_prefix xattr_types[];
+
struct xattr_iter_ops {
int (*verify)(const struct erofs_xattr_entry *entry);
+ int (*list)(const struct erofs_xattr_entry *entry, void *data);
+ int (*get)(const struct erofs_xattr_entry *entry, void *data);
};
int erofs_prepare_xattr_ibody(struct erofs_inode *inode);
diff --git a/lib/xattr.c b/lib/xattr.c
index 92c155d..eed3c71 100644
--- a/lib/xattr.c
+++ b/lib/xattr.c
@@ -39,10 +39,7 @@ static DECLARE_HASHTABLE(ea_hashtable, EA_HASHTABLE_BITS);
static LIST_HEAD(shared_xattrs_list);
static unsigned int shared_xattrs_count, shared_xattrs_size;
-static struct xattr_prefix {
- const char *prefix;
- u16 prefix_len;
-} xattr_types[] = {
+struct xattr_prefix xattr_types[] = {
[EROFS_XATTR_INDEX_USER] = {
XATTR_USER_PREFIX,
XATTR_USER_PREFIX_LEN
@@ -811,6 +808,17 @@ int erofs_xattr_foreach(struct erofs_inode *vi, struct xattr_iter_ops *ops,
if (ret < 0)
return ret;
}
+ if (ops->list) {
+ ret = ops->list(entry, data);
+ if (ret < 0)
+ return ret;
+ }
+ if (ops->get) {
+ ret = ops->get(entry, data);
+ if ((ret < 0 && ret != -ENODATA) || ret >= 0)
+ /* error or found */
+ return ret;
+ }
ofs += xattr_entry_size;
addr += xattr_entry_size;
@@ -830,6 +838,16 @@ int erofs_xattr_foreach(struct erofs_inode *vi, struct xattr_iter_ops *ops,
if (ret < 0)
return ret;
}
+ if (ops->list) {
+ ret = ops->list(entry, data);
+ if (ret < 0)
+ return ret;
+ }
+ if (ops->get) {
+ ret = ops->get(entry, data);
+ if ((ret < 0 && ret != -ENODATA) || ret >= 0)
+ return ret;
+ }
addr += entry_sz;
remaining -= entry_sz;
}
--
2.25.1
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