diff options
Diffstat (limited to 'fs/generic_acl.c')
| -rw-r--r-- | fs/generic_acl.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/fs/generic_acl.c b/fs/generic_acl.c new file mode 100644 index 000000000000..9ccb78947171 --- /dev/null +++ b/fs/generic_acl.c @@ -0,0 +1,197 @@ +/* + * fs/generic_acl.c + * + * (C) 2005 Andreas Gruenbacher <agruen@suse.de> + * + * This file is released under the GPL. + */ + +#include <linux/sched.h> +#include <linux/fs.h> +#include <linux/generic_acl.h> + +/** + * generic_acl_list - Generic xattr_handler->list() operation + * @ops: Filesystem specific getacl and setacl callbacks + */ +size_t +generic_acl_list(struct inode *inode, struct generic_acl_operations *ops, + int type, char *list, size_t list_size) +{ + struct posix_acl *acl; + const char *name; + size_t size; + + acl = ops->getacl(inode, type); + if (!acl) + return 0; + posix_acl_release(acl); + + switch(type) { + case ACL_TYPE_ACCESS: + name = POSIX_ACL_XATTR_ACCESS; + break; + + case ACL_TYPE_DEFAULT: + name = POSIX_ACL_XATTR_DEFAULT; + break; + + default: + return 0; + } + size = strlen(name) + 1; + if (list && size <= list_size) + memcpy(list, name, size); + return size; +} + +/** + * generic_acl_get - Generic xattr_handler->get() operation + * @ops: Filesystem specific getacl and setacl callbacks + */ +int +generic_acl_get(struct inode *inode, struct generic_acl_operations *ops, + int type, void *buffer, size_t size) +{ + struct posix_acl *acl; + int error; + + acl = ops->getacl(inode, type); + if (!acl) + return -ENODATA; + error = posix_acl_to_xattr(acl, buffer, size); + posix_acl_release(acl); + + return error; +} + +/** + * generic_acl_set - Generic xattr_handler->set() operation + * @ops: Filesystem specific getacl and setacl callbacks + */ +int +generic_acl_set(struct inode *inode, struct generic_acl_operations *ops, + int type, const void *value, size_t size) +{ + struct posix_acl *acl = NULL; + int error; + + if (S_ISLNK(inode->i_mode)) + return -EOPNOTSUPP; + if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER)) + return -EPERM; + if (value) { + acl = posix_acl_from_xattr(value, size); + if (IS_ERR(acl)) + return PTR_ERR(acl); + } + if (acl) { + mode_t mode; + + error = posix_acl_valid(acl); + if (error) + goto failed; + switch(type) { + case ACL_TYPE_ACCESS: + mode = inode->i_mode; + error = posix_acl_equiv_mode(acl, &mode); + if (error < 0) + goto failed; + inode->i_mode = mode; + if (error == 0) { + posix_acl_release(acl); + acl = NULL; + } + break; + + case ACL_TYPE_DEFAULT: + if (!S_ISDIR(inode->i_mode)) { + error = -EINVAL; + goto failed; + } + break; + } + } + ops->setacl(inode, type, acl); + error = 0; +failed: + posix_acl_release(acl); + return error; +} + +/** + * generic_acl_init - Take care of acl inheritance at @inode create time + * @ops: Filesystem specific getacl and setacl callbacks + * + * Files created inside a directory with a default ACL inherit the + * directory's default ACL. + */ +int +generic_acl_init(struct inode *inode, struct inode *dir, + struct generic_acl_operations *ops) +{ + struct posix_acl *acl = NULL; + mode_t mode = inode->i_mode; + int error; + + inode->i_mode = mode & ~current->fs->umask; + if (!S_ISLNK(inode->i_mode)) + acl = ops->getacl(dir, ACL_TYPE_DEFAULT); + if (acl) { + struct posix_acl *clone; + + if (S_ISDIR(inode->i_mode)) { + clone = posix_acl_clone(acl, GFP_KERNEL); + error = -ENOMEM; + if (!clone) + goto cleanup; + ops->setacl(inode, ACL_TYPE_DEFAULT, clone); + posix_acl_release(clone); + } + clone = posix_acl_clone(acl, GFP_KERNEL); + error = -ENOMEM; + if (!clone) + goto cleanup; + error = posix_acl_create_masq(clone, &mode); + if (error >= 0) { + inode->i_mode = mode; + if (error > 0) + ops->setacl(inode, ACL_TYPE_ACCESS, clone); + } + posix_acl_release(clone); + } + error = 0; + +cleanup: + posix_acl_release(acl); + return error; +} + +/** + * generic_acl_chmod - change the access acl of @inode upon chmod() + * @ops: FIlesystem specific getacl and setacl callbacks + * + * A chmod also changes the permissions of the owner, group/mask, and + * other ACL entries. + */ +int +generic_acl_chmod(struct inode *inode, struct generic_acl_operations *ops) +{ + struct posix_acl *acl, *clone; + int error = 0; + + if (S_ISLNK(inode->i_mode)) + return -EOPNOTSUPP; + acl = ops->getacl(inode, ACL_TYPE_ACCESS); + if (acl) { + clone = posix_acl_clone(acl, GFP_KERNEL); + posix_acl_release(acl); + if (!clone) + return -ENOMEM; + error = posix_acl_chmod_masq(clone, inode->i_mode); + if (!error) + ops->setacl(inode, ACL_TYPE_ACCESS, clone); + posix_acl_release(clone); + } + return error; +} |