ceph: add acl for cephfs

Signed-off-by: Guangliang Zhao <lucienchao@gmail.com>
Reviewed-by: Li Wang <li.wang@ubuntykylin.com>
Reviewed-by: Zheng Yan <zheng.z.yan@intel.com>

fs/ceph/Kconfig

@@ -25,3 +25,16 @@ config CEPH_FSCACHE
 	  caching support for Ceph clients using FS-Cache
 
 endif
+
+config CEPH_FS_POSIX_ACL
+	bool "Ceph POSIX Access Control Lists"
+	depends on CEPH_FS
+	select FS_POSIX_ACL
+	help
+	  POSIX Access Control Lists (ACLs) support permissions for users and
+	  groups beyond the owner/group/world scheme.
+
+	  To learn more about Access Control Lists, visit the POSIX ACLs for
+	  Linux website <http://acl.bestbits.at/>.
+
+	  If you don't know what Access Control Lists are, say N

fs/ceph/Makefile

@@ -10,3 +10,4 @@ ceph-y := super.o inode.o dir.o file.o locks.o addr.o ioctl.o \
 	debugfs.o
 
 ceph-$(CONFIG_CEPH_FSCACHE) += cache.o
+ceph-$(CONFIG_CEPH_FS_POSIX_ACL) += acl.o

fs/ceph/acl.c

@@ -0,0 +1,332 @@
+/*
+ * linux/fs/ceph/acl.c
+ *
+ * Copyright (C) 2013 Guangliang Zhao, <lucienchao@gmail.com>
+ *
+ * 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/ceph/ceph_debug.h>
+#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 <linux/slab.h>
+
+#include "super.h"
+
+static inline void ceph_set_cached_acl(struct inode *inode,
+					int type, struct posix_acl *acl)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+
+	spin_lock(&ci->i_ceph_lock);
+	if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0))
+		set_cached_acl(inode, type, acl);
+	spin_unlock(&ci->i_ceph_lock);
+}
+
+static inline struct posix_acl *ceph_get_cached_acl(struct inode *inode,
+							int type)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct posix_acl *acl = ACL_NOT_CACHED;
+
+	spin_lock(&ci->i_ceph_lock);
+	if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0))
+		acl = get_cached_acl(inode, type);
+	spin_unlock(&ci->i_ceph_lock);
+
+	return acl;
+}
+
+void ceph_forget_all_cached_acls(struct inode *inode)
+{
+	forget_all_cached_acls(inode);
+}
+
+struct posix_acl *ceph_get_acl(struct inode *inode, int type)
+{
+	int size;
+	const char *name;
+	char *value = NULL;
+	struct posix_acl *acl;
+
+	if (!IS_POSIXACL(inode))
+		return NULL;
+
+	acl = ceph_get_cached_acl(inode, type);
+	if (acl != ACL_NOT_CACHED)
+		return acl;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		name = POSIX_ACL_XATTR_ACCESS;
+		break;
+	case ACL_TYPE_DEFAULT:
+		name = POSIX_ACL_XATTR_DEFAULT;
+		break;
+	default:
+		BUG();
+	}
+
+	size = __ceph_getxattr(inode, name, "", 0);
+	if (size > 0) {
+		value = kzalloc(size, GFP_NOFS);
+		if (!value)
+			return ERR_PTR(-ENOMEM);
+		size = __ceph_getxattr(inode, name, value, size);
+	}
+
+	if (size > 0)
+		acl = posix_acl_from_xattr(&init_user_ns, value, size);
+	else if (size == -ERANGE || size == -ENODATA || size == 0)
+		acl = NULL;
+	else
+		acl = ERR_PTR(-EIO);
+
+	kfree(value);
+
+	if (!IS_ERR(acl))
+		ceph_set_cached_acl(inode, type, acl);
+
+	return acl;
+}
+
+static int ceph_set_acl(struct dentry *dentry, struct inode *inode,
+				struct posix_acl *acl, int type)
+{
+	int ret = 0, size = 0;
+	const char *name = NULL;
+	char *value = NULL;
+	struct iattr newattrs;
+	umode_t new_mode = inode->i_mode, old_mode = inode->i_mode;
+
+	if (acl) {
+		ret = posix_acl_valid(acl);
+		if (ret < 0)
+			goto out;
+	}
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		name = POSIX_ACL_XATTR_ACCESS;
+		if (acl) {
+			ret = posix_acl_equiv_mode(acl, &new_mode);
+			if (ret < 0)
+				goto out;
+			if (ret == 0)
+				acl = NULL;
+		}
+		break;
+	case ACL_TYPE_DEFAULT:
+		if (!S_ISDIR(inode->i_mode)) {
+			ret = acl ? -EINVAL : 0;
+			goto out;
+		}
+		name = POSIX_ACL_XATTR_DEFAULT;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+
+	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(&init_user_ns, acl, value, size);
+		if (ret < 0)
+			goto out_free;
+	}
+
+	if (new_mode != old_mode) {
+		newattrs.ia_mode = new_mode;
+		newattrs.ia_valid = ATTR_MODE;
+		ret = ceph_setattr(dentry, &newattrs);
+		if (ret)
+			goto out_free;
+	}
+
+	if (value)
+		ret = __ceph_setxattr(dentry, name, value, size, 0);
+	else
+		ret = __ceph_removexattr(dentry, name);
+
+	if (ret) {
+		if (new_mode != old_mode) {
+			newattrs.ia_mode = old_mode;
+			newattrs.ia_valid = ATTR_MODE;
+			ceph_setattr(dentry, &newattrs);
+		}
+		goto out_free;
+	}
+
+	ceph_set_cached_acl(inode, type, acl);
+
+out_free:
+	kfree(value);
+out:
+	return ret;
+}
+
+int ceph_init_acl(struct dentry *dentry, struct inode *inode, struct inode *dir)
+{
+	struct posix_acl *acl = NULL;
+	int ret = 0;
+
+	if (!S_ISLNK(inode->i_mode)) {
+		if (IS_POSIXACL(dir)) {
+			acl = ceph_get_acl(dir, ACL_TYPE_DEFAULT);
+			if (IS_ERR(acl)) {
+				ret = PTR_ERR(acl);
+				goto out;
+			}
+		}
+
+		if (!acl)
+			inode->i_mode &= ~current_umask();
+	}
+
+	if (IS_POSIXACL(dir) && acl) {
+		if (S_ISDIR(inode->i_mode)) {
+			ret = ceph_set_acl(dentry, inode, acl,
+						ACL_TYPE_DEFAULT);
+			if (ret)
+				goto out_release;
+		}
+		ret = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
+		if (ret < 0)
+			goto out;
+		else if (ret > 0)
+			ret = ceph_set_acl(dentry, inode, acl, ACL_TYPE_ACCESS);
+		else
+			cache_no_acl(inode);
+	} else {
+		cache_no_acl(inode);
+	}
+
+out_release:
+	posix_acl_release(acl);
+out:
+	return ret;
+}
+
+int ceph_acl_chmod(struct dentry *dentry, struct inode *inode)
+{
+	struct posix_acl *acl;
+	int ret = 0;
+
+	if (S_ISLNK(inode->i_mode)) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	if (!IS_POSIXACL(inode))
+		goto out;
+
+	acl = ceph_get_acl(inode, ACL_TYPE_ACCESS);
+	if (IS_ERR_OR_NULL(acl)) {
+		ret = PTR_ERR(acl);
+		goto out;
+	}
+
+	ret = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
+	if (ret)
+		goto out;
+	ret = ceph_set_acl(dentry, inode, acl, ACL_TYPE_ACCESS);
+	posix_acl_release(acl);
+out:
+	return ret;
+}
+
+static int ceph_xattr_acl_get(struct dentry *dentry, const char *name,
+				void *value, size_t size, int type)
+{
+	struct posix_acl *acl;
+	int ret = 0;
+
+	if (!IS_POSIXACL(dentry->d_inode))
+		return -EOPNOTSUPP;
+
+	acl = ceph_get_acl(dentry->d_inode, type);
+	if (IS_ERR(acl))
+		return PTR_ERR(acl);
+	if (acl == NULL)
+		return -ENODATA;
+
+	ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
+	posix_acl_release(acl);
+
+	return ret;
+}
+
+static int ceph_xattr_acl_set(struct dentry *dentry, const char *name,
+			const void *value, size_t size, int flags, int type)
+{
+	int ret = 0;
+	struct posix_acl *acl = NULL;
+
+	if (!inode_owner_or_capable(dentry->d_inode)) {
+		ret = -EPERM;
+		goto out;
+	}
+
+	if (!IS_POSIXACL(dentry->d_inode)) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	if (value) {
+		acl = posix_acl_from_xattr(&init_user_ns, value, size);
+		if (IS_ERR(acl)) {
+			ret = PTR_ERR(acl);
+			goto out;
+		}
+
+		if (acl) {
+			ret = posix_acl_valid(acl);
+			if (ret)
+				goto out_release;
+		}
+	}
+
+	ret = ceph_set_acl(dentry, dentry->d_inode, acl, type);
+
+out_release:
+	posix_acl_release(acl);
+out:
+	return ret;
+}
+
+const struct xattr_handler ceph_xattr_acl_default_handler = {
+	.prefix = POSIX_ACL_XATTR_DEFAULT,
+	.flags  = ACL_TYPE_DEFAULT,
+	.get    = ceph_xattr_acl_get,
+	.set    = ceph_xattr_acl_set,
+};
+
+const struct xattr_handler ceph_xattr_acl_access_handler = {
+	.prefix = POSIX_ACL_XATTR_ACCESS,
+	.flags  = ACL_TYPE_ACCESS,
+	.get    = ceph_xattr_acl_get,
+	.set    = ceph_xattr_acl_set,
+};

fs/ceph/caps.c

@@ -2464,6 +2464,7 @@ static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
 				ceph_buffer_put(ci->i_xattrs.blob);
 			ci->i_xattrs.blob = ceph_buffer_get(xattr_buf);
 			ci->i_xattrs.version = version;
+			ceph_forget_all_cached_acls(inode);
 		}
 	}
 

fs/ceph/dir.c

@@ -693,6 +693,10 @@ static int ceph_mknod(struct inode *dir, struct dentry *dentry,
 	if (!err && !req->r_reply_info.head->is_dentry)
 		err = ceph_handle_notrace_create(dir, dentry);
 	ceph_mdsc_put_request(req);
+
+	if (!err)
+		err = ceph_init_acl(dentry, dentry->d_inode, dir);
+
 	if (err)
 		d_drop(dentry);
 	return err;
@@ -1293,6 +1297,7 @@ const struct inode_operations ceph_dir_iops = {
 	.getxattr = ceph_getxattr,
 	.listxattr = ceph_listxattr,
 	.removexattr = ceph_removexattr,
+	.get_acl = ceph_get_acl,
 	.mknod = ceph_mknod,
 	.symlink = ceph_symlink,
 	.mkdir = ceph_mkdir,