X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=blobdiff_plain;f=fs%2Fxattr.c;h=3368659c471e4f7dc8cd425738bccb7d5fec78a6;hp=c243905835abd25b52eb8daf061b5f11b3a5708e;hb=6f2e0d2c3bf0f8d322ab7516c57340c7189cca02;hpb=ae4860b5333586b60ca1798f3f83b8b37520904c diff --git a/fs/xattr.c b/fs/xattr.c index c243905835ab..3368659c471e 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -24,6 +24,59 @@ #include +static const char * +strcmp_prefix(const char *a, const char *a_prefix) +{ + while (*a_prefix && *a == *a_prefix) { + a++; + a_prefix++; + } + return *a_prefix ? NULL : a; +} + +/* + * In order to implement different sets of xattr operations for each xattr + * prefix, a filesystem should create a null-terminated array of struct + * xattr_handler (one for each prefix) and hang a pointer to it off of the + * s_xattr field of the superblock. + */ +#define for_each_xattr_handler(handlers, handler) \ + if (handlers) \ + for ((handler) = *(handlers)++; \ + (handler) != NULL; \ + (handler) = *(handlers)++) + +/* + * Find the xattr_handler with the matching prefix. + */ +static const struct xattr_handler * +xattr_resolve_name(struct inode *inode, const char **name) +{ + const struct xattr_handler **handlers = inode->i_sb->s_xattr; + const struct xattr_handler *handler; + + if (!(inode->i_opflags & IOP_XATTR)) { + if (unlikely(is_bad_inode(inode))) + return ERR_PTR(-EIO); + return ERR_PTR(-EOPNOTSUPP); + } + for_each_xattr_handler(handlers, handler) { + const char *n; + + n = strcmp_prefix(*name, xattr_prefix(handler)); + if (n) { + if (!handler->prefix ^ !*n) { + if (*n) + continue; + return ERR_PTR(-EINVAL); + } + *name = n; + return handler; + } + } + return ERR_PTR(-EOPNOTSUPP); +} + /* * Check permissions for extended attribute access. This is a bit complicated * because different namespaces have very different rules. @@ -80,6 +133,23 @@ xattr_permission(struct inode *inode, const char *name, int mask) return inode_permission(inode, mask); } +int +__vfs_setxattr(struct dentry *dentry, struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + const struct xattr_handler *handler; + + handler = xattr_resolve_name(inode, &name); + if (IS_ERR(handler)) + return PTR_ERR(handler); + if (!handler->set) + return -EOPNOTSUPP; + if (size == 0) + value = ""; /* empty EA, do not remove */ + return handler->set(handler, dentry, inode, name, value, size, flags); +} +EXPORT_SYMBOL(__vfs_setxattr); + /** * __vfs_setxattr_noperm - perform setxattr operation without performing * permission checks. @@ -106,8 +176,8 @@ int __vfs_setxattr_noperm(struct dentry *dentry, const char *name, if (issec) inode->i_flags &= ~S_NOSEC; - if (inode->i_op->setxattr) { - error = inode->i_op->setxattr(dentry, inode, name, value, size, flags); + if (inode->i_opflags & IOP_XATTR) { + error = __vfs_setxattr(dentry, inode, name, value, size, flags); if (!error) { fsnotify_xattr(dentry); security_inode_post_setxattr(dentry, name, value, @@ -115,6 +185,9 @@ int __vfs_setxattr_noperm(struct dentry *dentry, const char *name, } } else if (issec) { const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; + + if (unlikely(is_bad_inode(inode))) + return -EIO; error = security_inode_setsecurity(inode, suffix, value, size, flags); if (!error) @@ -188,6 +261,7 @@ ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value, size_t xattr_size, gfp_t flags) { + const struct xattr_handler *handler; struct inode *inode = dentry->d_inode; char *value = *xattr_value; int error; @@ -196,10 +270,12 @@ vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value, if (error) return error; - if (!inode->i_op->getxattr) + handler = xattr_resolve_name(inode, &name); + if (IS_ERR(handler)) + return PTR_ERR(handler); + if (!handler->get) return -EOPNOTSUPP; - - error = inode->i_op->getxattr(dentry, inode, name, NULL, 0); + error = handler->get(handler, dentry, inode, name, NULL, 0); if (error < 0) return error; @@ -210,11 +286,26 @@ vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value, memset(value, 0, error + 1); } - error = inode->i_op->getxattr(dentry, inode, name, value, error); + error = handler->get(handler, dentry, inode, name, value, error); *xattr_value = value; return error; } +ssize_t +__vfs_getxattr(struct dentry *dentry, struct inode *inode, const char *name, + void *value, size_t size) +{ + const struct xattr_handler *handler; + + handler = xattr_resolve_name(inode, &name); + if (IS_ERR(handler)) + return PTR_ERR(handler); + if (!handler->get) + return -EOPNOTSUPP; + return handler->get(handler, dentry, inode, name, value, size); +} +EXPORT_SYMBOL(__vfs_getxattr); + ssize_t vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) { @@ -242,28 +333,24 @@ vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) return ret; } nolsm: - if (inode->i_op->getxattr) - error = inode->i_op->getxattr(dentry, inode, name, value, size); - else - error = -EOPNOTSUPP; - - return error; + return __vfs_getxattr(dentry, inode, name, value, size); } EXPORT_SYMBOL_GPL(vfs_getxattr); ssize_t -vfs_listxattr(struct dentry *d, char *list, size_t size) +vfs_listxattr(struct dentry *dentry, char *list, size_t size) { + struct inode *inode = d_inode(dentry); ssize_t error; - error = security_inode_listxattr(d); + error = security_inode_listxattr(dentry); if (error) return error; - error = -EOPNOTSUPP; - if (d->d_inode->i_op->listxattr) { - error = d->d_inode->i_op->listxattr(d, list, size); + if (inode->i_op->listxattr && (inode->i_opflags & IOP_XATTR)) { + error = -EOPNOTSUPP; + error = inode->i_op->listxattr(dentry, list, size); } else { - error = security_inode_listsecurity(d->d_inode, list, size); + error = security_inode_listsecurity(inode, list, size); if (size && error > size) error = -ERANGE; } @@ -271,15 +358,27 @@ vfs_listxattr(struct dentry *d, char *list, size_t size) } EXPORT_SYMBOL_GPL(vfs_listxattr); +int +__vfs_removexattr(struct dentry *dentry, const char *name) +{ + struct inode *inode = d_inode(dentry); + const struct xattr_handler *handler; + + handler = xattr_resolve_name(inode, &name); + if (IS_ERR(handler)) + return PTR_ERR(handler); + if (!handler->set) + return -EOPNOTSUPP; + return handler->set(handler, dentry, inode, name, NULL, 0, XATTR_REPLACE); +} +EXPORT_SYMBOL(__vfs_removexattr); + int vfs_removexattr(struct dentry *dentry, const char *name) { struct inode *inode = dentry->d_inode; int error; - if (!inode->i_op->removexattr) - return -EOPNOTSUPP; - error = xattr_permission(inode, name, MAY_WRITE); if (error) return error; @@ -289,7 +388,7 @@ vfs_removexattr(struct dentry *dentry, const char *name) if (error) goto out; - error = inode->i_op->removexattr(dentry, name); + error = __vfs_removexattr(dentry, name); if (!error) { fsnotify_xattr(dentry); @@ -641,76 +740,6 @@ SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) return error; } - -static const char * -strcmp_prefix(const char *a, const char *a_prefix) -{ - while (*a_prefix && *a == *a_prefix) { - a++; - a_prefix++; - } - return *a_prefix ? NULL : a; -} - -/* - * In order to implement different sets of xattr operations for each xattr - * prefix with the generic xattr API, a filesystem should create a - * null-terminated array of struct xattr_handler (one for each prefix) and - * hang a pointer to it off of the s_xattr field of the superblock. - * - * The generic_fooxattr() functions will use this list to dispatch xattr - * operations to the correct xattr_handler. - */ -#define for_each_xattr_handler(handlers, handler) \ - if (handlers) \ - for ((handler) = *(handlers)++; \ - (handler) != NULL; \ - (handler) = *(handlers)++) - -/* - * Find the xattr_handler with the matching prefix. - */ -static const struct xattr_handler * -xattr_resolve_name(const struct xattr_handler **handlers, const char **name) -{ - const struct xattr_handler *handler; - - if (!*name) - return ERR_PTR(-EINVAL); - - for_each_xattr_handler(handlers, handler) { - const char *n; - - n = strcmp_prefix(*name, xattr_prefix(handler)); - if (n) { - if (!handler->prefix ^ !*n) { - if (*n) - continue; - return ERR_PTR(-EINVAL); - } - *name = n; - return handler; - } - } - return ERR_PTR(-EOPNOTSUPP); -} - -/* - * Find the handler for the prefix and dispatch its get() operation. - */ -ssize_t -generic_getxattr(struct dentry *dentry, struct inode *inode, - const char *name, void *buffer, size_t size) -{ - const struct xattr_handler *handler; - - handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); - if (IS_ERR(handler)) - return PTR_ERR(handler); - return handler->get(handler, dentry, inode, - name, buffer, size); -} - /* * Combine the results of the list() operation from every xattr_handler in the * list. @@ -747,44 +776,7 @@ generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) } return size; } - -/* - * Find the handler for the prefix and dispatch its set() operation. - */ -int -generic_setxattr(struct dentry *dentry, struct inode *inode, const char *name, - const void *value, size_t size, int flags) -{ - const struct xattr_handler *handler; - - if (size == 0) - value = ""; /* empty EA, do not remove */ - handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); - if (IS_ERR(handler)) - return PTR_ERR(handler); - return handler->set(handler, dentry, inode, name, value, size, flags); -} - -/* - * Find the handler for the prefix and dispatch its set() operation to remove - * any associated extended attribute. - */ -int -generic_removexattr(struct dentry *dentry, const char *name) -{ - const struct xattr_handler *handler; - - handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); - if (IS_ERR(handler)) - return PTR_ERR(handler); - return handler->set(handler, dentry, d_inode(dentry), name, NULL, - 0, XATTR_REPLACE); -} - -EXPORT_SYMBOL(generic_getxattr); EXPORT_SYMBOL(generic_listxattr); -EXPORT_SYMBOL(generic_setxattr); -EXPORT_SYMBOL(generic_removexattr); /** * xattr_full_name - Compute full attribute name from suffix