From aa7c5241c380adb7e6913549292c1b83c1469bda Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Wed, 2 Dec 2015 14:44:38 +0100 Subject: tmpfs: Use xattr handler infrastructure Use the VFS xattr handler infrastructure and get rid of similar code in the filesystem. For implementing shmem_xattr_handler_set, we need a version of simple_xattr_set which removes the attribute when value is NULL. Use this to implement kernfs_iop_removexattr as well. Signed-off-by: Andreas Gruenbacher Reviewed-by: James Morris Cc: Hugh Dickins Cc: linux-mm@kvack.org Signed-off-by: Al Viro --- mm/shmem.c | 131 ++++++++++++++++++++----------------------------------------- 1 file changed, 42 insertions(+), 89 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index 9187eee4128b..fdfe6c8dddfc 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2561,94 +2561,47 @@ static int shmem_initxattrs(struct inode *inode, return 0; } -static const struct xattr_handler *shmem_xattr_handlers[] = { -#ifdef CONFIG_TMPFS_POSIX_ACL - &posix_acl_access_xattr_handler, - &posix_acl_default_xattr_handler, -#endif - NULL -}; - -static int shmem_xattr_validate(const char *name) -{ - struct { const char *prefix; size_t len; } arr[] = { - { XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN }, - { XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN } - }; - int i; - - for (i = 0; i < ARRAY_SIZE(arr); i++) { - size_t preflen = arr[i].len; - if (strncmp(name, arr[i].prefix, preflen) == 0) { - if (!name[preflen]) - return -EINVAL; - return 0; - } - } - return -EOPNOTSUPP; -} - -static ssize_t shmem_getxattr(struct dentry *dentry, const char *name, - void *buffer, size_t size) +static int shmem_xattr_handler_get(const struct xattr_handler *handler, + struct dentry *dentry, const char *name, + void *buffer, size_t size) { struct shmem_inode_info *info = SHMEM_I(d_inode(dentry)); - int err; - - /* - * If this is a request for a synthetic attribute in the system.* - * namespace use the generic infrastructure to resolve a handler - * for it via sb->s_xattr. - */ - if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) - return generic_getxattr(dentry, name, buffer, size); - - err = shmem_xattr_validate(name); - if (err) - return err; + name = xattr_full_name(handler, name); return simple_xattr_get(&info->xattrs, name, buffer, size); } -static int shmem_setxattr(struct dentry *dentry, const char *name, - const void *value, size_t size, int flags) +static int shmem_xattr_handler_set(const struct xattr_handler *handler, + struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) { struct shmem_inode_info *info = SHMEM_I(d_inode(dentry)); - int err; - - /* - * If this is a request for a synthetic attribute in the system.* - * namespace use the generic infrastructure to resolve a handler - * for it via sb->s_xattr. - */ - if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) - return generic_setxattr(dentry, name, value, size, flags); - - err = shmem_xattr_validate(name); - if (err) - return err; + name = xattr_full_name(handler, name); return simple_xattr_set(&info->xattrs, name, value, size, flags); } -static int shmem_removexattr(struct dentry *dentry, const char *name) -{ - struct shmem_inode_info *info = SHMEM_I(d_inode(dentry)); - int err; - - /* - * If this is a request for a synthetic attribute in the system.* - * namespace use the generic infrastructure to resolve a handler - * for it via sb->s_xattr. - */ - if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) - return generic_removexattr(dentry, name); +static const struct xattr_handler shmem_security_xattr_handler = { + .prefix = XATTR_SECURITY_PREFIX, + .get = shmem_xattr_handler_get, + .set = shmem_xattr_handler_set, +}; - err = shmem_xattr_validate(name); - if (err) - return err; +static const struct xattr_handler shmem_trusted_xattr_handler = { + .prefix = XATTR_TRUSTED_PREFIX, + .get = shmem_xattr_handler_get, + .set = shmem_xattr_handler_set, +}; - return simple_xattr_remove(&info->xattrs, name); -} +static const struct xattr_handler *shmem_xattr_handlers[] = { +#ifdef CONFIG_TMPFS_POSIX_ACL + &posix_acl_access_xattr_handler, + &posix_acl_default_xattr_handler, +#endif + &shmem_security_xattr_handler, + &shmem_trusted_xattr_handler, + NULL +}; static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size) { @@ -2661,10 +2614,10 @@ static const struct inode_operations shmem_short_symlink_operations = { .readlink = generic_readlink, .follow_link = simple_follow_link, #ifdef CONFIG_TMPFS_XATTR - .setxattr = shmem_setxattr, - .getxattr = shmem_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = shmem_listxattr, - .removexattr = shmem_removexattr, + .removexattr = generic_removexattr, #endif }; @@ -2673,10 +2626,10 @@ static const struct inode_operations shmem_symlink_inode_operations = { .follow_link = shmem_follow_link, .put_link = shmem_put_link, #ifdef CONFIG_TMPFS_XATTR - .setxattr = shmem_setxattr, - .getxattr = shmem_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = shmem_listxattr, - .removexattr = shmem_removexattr, + .removexattr = generic_removexattr, #endif }; @@ -3148,10 +3101,10 @@ static const struct inode_operations shmem_inode_operations = { .getattr = shmem_getattr, .setattr = shmem_setattr, #ifdef CONFIG_TMPFS_XATTR - .setxattr = shmem_setxattr, - .getxattr = shmem_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = shmem_listxattr, - .removexattr = shmem_removexattr, + .removexattr = generic_removexattr, .set_acl = simple_set_acl, #endif }; @@ -3170,10 +3123,10 @@ static const struct inode_operations shmem_dir_inode_operations = { .tmpfile = shmem_tmpfile, #endif #ifdef CONFIG_TMPFS_XATTR - .setxattr = shmem_setxattr, - .getxattr = shmem_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = shmem_listxattr, - .removexattr = shmem_removexattr, + .removexattr = generic_removexattr, #endif #ifdef CONFIG_TMPFS_POSIX_ACL .setattr = shmem_setattr, @@ -3183,10 +3136,10 @@ static const struct inode_operations shmem_dir_inode_operations = { static const struct inode_operations shmem_special_inode_operations = { #ifdef CONFIG_TMPFS_XATTR - .setxattr = shmem_setxattr, - .getxattr = shmem_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = shmem_listxattr, - .removexattr = shmem_removexattr, + .removexattr = generic_removexattr, #endif #ifdef CONFIG_TMPFS_POSIX_ACL .setattr = shmem_setattr, -- cgit v1.2.3