diff options
Diffstat (limited to 'fs/btrfs/acl.c')
-rw-r--r-- | fs/btrfs/acl.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c new file mode 100644 index 000000000000..867eaf1f8efb --- /dev/null +++ b/fs/btrfs/acl.c @@ -0,0 +1,352 @@ +/* + * Copyright (C) 2007 Red Hat. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include <linux/fs.h> +#include <linux/string.h> +#include <linux/xattr.h> +#include <linux/posix_acl_xattr.h> +#include <linux/posix_acl.h> +#include <linux/sched.h> + +#include "ctree.h" +#include "btrfs_inode.h" +#include "xattr.h" + +#ifdef CONFIG_FS_POSIX_ACL + +static void btrfs_update_cached_acl(struct inode *inode, + struct posix_acl **p_acl, + struct posix_acl *acl) +{ + spin_lock(&inode->i_lock); + if (*p_acl && *p_acl != BTRFS_ACL_NOT_CACHED) + posix_acl_release(*p_acl); + *p_acl = posix_acl_dup(acl); + spin_unlock(&inode->i_lock); +} + +static struct posix_acl *btrfs_get_acl(struct inode *inode, int type) +{ + int size; + const char *name; + char *value = NULL; + struct posix_acl *acl = NULL, **p_acl; + + switch (type) { + case ACL_TYPE_ACCESS: + name = POSIX_ACL_XATTR_ACCESS; + p_acl = &BTRFS_I(inode)->i_acl; + break; + case ACL_TYPE_DEFAULT: + name = POSIX_ACL_XATTR_DEFAULT; + p_acl = &BTRFS_I(inode)->i_default_acl; + break; + default: + return ERR_PTR(-EINVAL); + } + + spin_lock(&inode->i_lock); + if (*p_acl != BTRFS_ACL_NOT_CACHED) + acl = posix_acl_dup(*p_acl); + spin_unlock(&inode->i_lock); + + if (acl) + return acl; + + + size = __btrfs_getxattr(inode, name, "", 0); + if (size > 0) { + value = kzalloc(size, GFP_NOFS); + if (!value) + return ERR_PTR(-ENOMEM); + size = __btrfs_getxattr(inode, name, value, size); + if (size > 0) { + acl = posix_acl_from_xattr(value, size); + btrfs_update_cached_acl(inode, p_acl, acl); + } + kfree(value); + } else if (size == -ENOENT) { + acl = NULL; + btrfs_update_cached_acl(inode, p_acl, acl); + } + + return acl; +} + +static int btrfs_xattr_get_acl(struct inode *inode, int type, + void *value, size_t size) +{ + struct posix_acl *acl; + int ret = 0; + + acl = btrfs_get_acl(inode, type); + + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl == NULL) + return -ENODATA; + ret = posix_acl_to_xattr(acl, value, size); + posix_acl_release(acl); + + return ret; +} + +/* + * Needs to be called with fs_mutex held + */ +static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) +{ + int ret, size = 0; + const char *name; + struct posix_acl **p_acl; + char *value = NULL; + mode_t mode; + + if (acl) { + ret = posix_acl_valid(acl); + if (ret < 0) + return ret; + ret = 0; + } + + switch (type) { + case ACL_TYPE_ACCESS: + mode = inode->i_mode; + ret = posix_acl_equiv_mode(acl, &mode); + if (ret < 0) + return ret; + ret = 0; + inode->i_mode = mode; + name = POSIX_ACL_XATTR_ACCESS; + p_acl = &BTRFS_I(inode)->i_acl; + break; + case ACL_TYPE_DEFAULT: + if (!S_ISDIR(inode->i_mode)) + return acl ? -EINVAL : 0; + name = POSIX_ACL_XATTR_DEFAULT; + p_acl = &BTRFS_I(inode)->i_default_acl; + break; + default: + return -EINVAL; + } + + if (acl) { + size = posix_acl_xattr_size(acl->a_count); + value = kmalloc(size, GFP_NOFS); + if (!value) { + ret = -ENOMEM; + goto out; + } + + ret = posix_acl_to_xattr(acl, value, size); + if (ret < 0) + goto out; + } + + ret = __btrfs_setxattr(inode, name, value, size, 0); + +out: + if (value) + kfree(value); + + if (!ret) + btrfs_update_cached_acl(inode, p_acl, acl); + + return ret; +} + +static int btrfs_xattr_set_acl(struct inode *inode, int type, + const void *value, size_t size) +{ + int ret = 0; + struct posix_acl *acl = NULL; + + if (value) { + acl = posix_acl_from_xattr(value, size); + if (acl == NULL) { + value = NULL; + size = 0; + } else if (IS_ERR(acl)) { + return PTR_ERR(acl); + } + } + + ret = btrfs_set_acl(inode, acl, type); + + posix_acl_release(acl); + + return ret; +} + + +static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name, + void *value, size_t size) +{ + return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size); +} + +static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size); +} + +static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name, + void *value, size_t size) +{ + return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size); +} + +static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size); +} + +int btrfs_check_acl(struct inode *inode, int mask) +{ + struct posix_acl *acl; + int error = -EAGAIN; + + acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); + + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl) { + error = posix_acl_permission(inode, acl, mask); + posix_acl_release(acl); + } + + return error; +} + +/* + * btrfs_init_acl is already generally called under fs_mutex, so the locking + * stuff has been fixed to work with that. If the locking stuff changes, we + * need to re-evaluate the acl locking stuff. + */ +int btrfs_init_acl(struct inode *inode, struct inode *dir) +{ + struct posix_acl *acl = NULL; + int ret = 0; + + /* this happens with subvols */ + if (!dir) + return 0; + + if (!S_ISLNK(inode->i_mode)) { + if (IS_POSIXACL(dir)) { + acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT); + if (IS_ERR(acl)) + return PTR_ERR(acl); + } + + if (!acl) + inode->i_mode &= ~current->fs->umask; + } + + if (IS_POSIXACL(dir) && acl) { + struct posix_acl *clone; + mode_t mode; + + if (S_ISDIR(inode->i_mode)) { + ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT); + if (ret) + goto failed; + } + clone = posix_acl_clone(acl, GFP_NOFS); + ret = -ENOMEM; + if (!clone) + goto failed; + + mode = inode->i_mode; + ret = posix_acl_create_masq(clone, &mode); + if (ret >= 0) { + inode->i_mode = mode; + if (ret > 0) { + /* we need an acl */ + ret = btrfs_set_acl(inode, clone, + ACL_TYPE_ACCESS); + } + } + } +failed: + posix_acl_release(acl); + + return ret; +} + +int btrfs_acl_chmod(struct inode *inode) +{ + struct posix_acl *acl, *clone; + int ret = 0; + + if (S_ISLNK(inode->i_mode)) + return -EOPNOTSUPP; + + if (!IS_POSIXACL(inode)) + return 0; + + acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); + if (IS_ERR(acl) || !acl) + return PTR_ERR(acl); + + clone = posix_acl_clone(acl, GFP_KERNEL); + posix_acl_release(acl); + if (!clone) + return -ENOMEM; + + ret = posix_acl_chmod_masq(clone, inode->i_mode); + if (!ret) + ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS); + + posix_acl_release(clone); + + return ret; +} + +struct xattr_handler btrfs_xattr_acl_default_handler = { + .prefix = POSIX_ACL_XATTR_DEFAULT, + .get = btrfs_xattr_acl_default_get, + .set = btrfs_xattr_acl_default_set, +}; + +struct xattr_handler btrfs_xattr_acl_access_handler = { + .prefix = POSIX_ACL_XATTR_ACCESS, + .get = btrfs_xattr_acl_access_get, + .set = btrfs_xattr_acl_access_set, +}; + +#else /* CONFIG_FS_POSIX_ACL */ + +int btrfs_acl_chmod(struct inode *inode) +{ + return 0; +} + +int btrfs_init_acl(struct inode *inode, struct inode *dir) +{ + return 0; +} + +int btrfs_check_acl(struct inode *inode, int mask) +{ + return 0; +} + +#endif /* CONFIG_FS_POSIX_ACL */ |