From f2620f166e2a4db08f016b7b30b904ab28c265e4 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 1 Feb 2023 14:14:52 +0100 Subject: [PATCH] xattr: simplify listxattr helpers The generic_listxattr() and simple_xattr_list() helpers list xattrs and contain duplicated code. Add two helpers that both generic_listxattr() and simple_xattr_list() can use. Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Microsoft) --- fs/posix_acl.c | 25 +++++++++++++ fs/xattr.c | 89 ++++++++++++++++++----------------------------- include/linux/posix_acl.h | 7 ++++ include/linux/xattr.h | 1 + 4 files changed, 66 insertions(+), 56 deletions(-) diff --git a/fs/posix_acl.c b/fs/posix_acl.c index 5a76fb3..b350e83 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -957,6 +957,31 @@ set_posix_acl(struct mnt_idmap *idmap, struct dentry *dentry, } EXPORT_SYMBOL(set_posix_acl); +int posix_acl_listxattr(struct inode *inode, char **buffer, + ssize_t *remaining_size) +{ + int err; + + if (!IS_POSIXACL(inode)) + return 0; + + if (inode->i_acl) { + err = xattr_list_one(buffer, remaining_size, + XATTR_NAME_POSIX_ACL_ACCESS); + if (err) + return err; + } + + if (inode->i_default_acl) { + err = xattr_list_one(buffer, remaining_size, + XATTR_NAME_POSIX_ACL_DEFAULT); + if (err) + return err; + } + + return 0; +} + static bool posix_acl_xattr_list(struct dentry *dentry) { diff --git a/fs/xattr.c b/fs/xattr.c index 14a7eb3..1a35235e 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -949,6 +949,21 @@ SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) return error; } +int xattr_list_one(char **buffer, ssize_t *remaining_size, const char *name) +{ + size_t len; + + len = strlen(name) + 1; + if (*buffer) { + if (*remaining_size < len) + return -ERANGE; + memcpy(*buffer, name, len); + *buffer += len; + } + *remaining_size -= len; + return 0; +} + /* * Combine the results of the list() operation from every xattr_handler in the * list. @@ -957,33 +972,22 @@ ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) { const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr; - unsigned int size = 0; - - if (!buffer) { - for_each_xattr_handler(handlers, handler) { - if (!handler->name || - (handler->list && !handler->list(dentry))) - continue; - size += strlen(handler->name) + 1; - } - } else { - char *buf = buffer; - size_t len; - - for_each_xattr_handler(handlers, handler) { - if (!handler->name || - (handler->list && !handler->list(dentry))) - continue; - len = strlen(handler->name); - if (len + 1 > buffer_size) - return -ERANGE; - memcpy(buf, handler->name, len + 1); - buf += len + 1; - buffer_size -= len + 1; - } - size = buf - buffer; + ssize_t remaining_size = buffer_size; + int err = 0; + + err = posix_acl_listxattr(d_inode(dentry), &buffer, &remaining_size); + if (err) + return err; + + for_each_xattr_handler(handlers, handler) { + if (!handler->name || (handler->list && !handler->list(dentry))) + continue; + err = xattr_list_one(&buffer, &remaining_size, handler->name); + if (err) + return err; } - return size; + + return err ? err : buffer_size - remaining_size; } EXPORT_SYMBOL(generic_listxattr); @@ -1245,20 +1249,6 @@ static bool xattr_is_trusted(const char *name) return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN); } -static int xattr_list_one(char **buffer, ssize_t *remaining_size, - const char *name) -{ - size_t len = strlen(name) + 1; - if (*buffer) { - if (*remaining_size < len) - return -ERANGE; - memcpy(*buffer, name, len); - *buffer += len; - } - *remaining_size -= len; - return 0; -} - /** * simple_xattr_list - list all xattr objects * @inode: inode from which to get the xattrs @@ -1287,22 +1277,9 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, ssize_t remaining_size = size; int err = 0; -#ifdef CONFIG_FS_POSIX_ACL - if (IS_POSIXACL(inode)) { - if (inode->i_acl) { - err = xattr_list_one(&buffer, &remaining_size, - XATTR_NAME_POSIX_ACL_ACCESS); - if (err) - return err; - } - if (inode->i_default_acl) { - err = xattr_list_one(&buffer, &remaining_size, - XATTR_NAME_POSIX_ACL_DEFAULT); - if (err) - return err; - } - } -#endif + err = posix_acl_listxattr(inode, &buffer, &remaining_size); + if (err) + return err; read_lock(&xattrs->lock); for (rbp = rb_first(&xattrs->rb_root); rbp; rbp = rb_next(rbp)) { diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h index 21cc29b..0e65b3d 100644 --- a/include/linux/posix_acl.h +++ b/include/linux/posix_acl.h @@ -106,6 +106,8 @@ struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name); int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name); +int posix_acl_listxattr(struct inode *inode, char **buffer, + ssize_t *remaining_size); #else static inline int posix_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry, umode_t mode) @@ -153,6 +155,11 @@ static inline int vfs_remove_acl(struct mnt_idmap *idmap, { return -EOPNOTSUPP; } +static inline int posix_acl_listxattr(struct inode *inode, char **buffer, + ssize_t *remaining_size) +{ + return 0; +} #endif /* CONFIG_FS_POSIX_ACL */ struct posix_acl *get_inode_acl(struct inode *inode, int type); diff --git a/include/linux/xattr.h b/include/linux/xattr.h index 6af7246..ce8fb0b 100644 --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -109,5 +109,6 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer, size_t size); void simple_xattr_add(struct simple_xattrs *xattrs, struct simple_xattr *new_xattr); +int xattr_list_one(char **buffer, ssize_t *remaining_size, const char *name); #endif /* _LINUX_XATTR_H */ -- 2.7.4