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-rw-r--r--fs/fuse/Kconfig1
-rw-r--r--fs/fuse/Makefile2
-rw-r--r--fs/fuse/acl.c99
-rw-r--r--fs/fuse/dir.c16
-rw-r--r--fs/fuse/fuse_i.h14
-rw-r--r--fs/fuse/inode.c9
-rw-r--r--fs/fuse/xattr.c18
-rw-r--r--include/uapi/linux/fuse.h3
8 files changed, 155 insertions, 7 deletions
diff --git a/fs/fuse/Kconfig b/fs/fuse/Kconfig
index 1b2f6c2c3aaf..76f09ce7e5b2 100644
--- a/fs/fuse/Kconfig
+++ b/fs/fuse/Kconfig
@@ -1,5 +1,6 @@
 config FUSE_FS
 	tristate "FUSE (Filesystem in Userspace) support"
+	select FS_POSIX_ACL
 	help
 	  With FUSE it is possible to implement a fully functional filesystem
 	  in a userspace program.
diff --git a/fs/fuse/Makefile b/fs/fuse/Makefile
index 448aa27ada00..60da84a86dab 100644
--- a/fs/fuse/Makefile
+++ b/fs/fuse/Makefile
@@ -5,4 +5,4 @@
 obj-$(CONFIG_FUSE_FS) += fuse.o
 obj-$(CONFIG_CUSE) += cuse.o
 
-fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o
+fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o acl.o
diff --git a/fs/fuse/acl.c b/fs/fuse/acl.c
new file mode 100644
index 000000000000..ec85765502f1
--- /dev/null
+++ b/fs/fuse/acl.c
@@ -0,0 +1,99 @@
+/*
+ * FUSE: Filesystem in Userspace
+ * Copyright (C) 2016 Canonical Ltd. <seth.forshee@canonical.com>
+ *
+ * This program can be distributed under the terms of the GNU GPL.
+ * See the file COPYING.
+ */
+
+#include "fuse_i.h"
+
+#include <linux/posix_acl.h>
+#include <linux/posix_acl_xattr.h>
+
+struct posix_acl *fuse_get_acl(struct inode *inode, int type)
+{
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	int size;
+	const char *name;
+	void *value = NULL;
+	struct posix_acl *acl;
+
+	if (!fc->posix_acl || fc->no_getxattr)
+		return NULL;
+
+	if (type == ACL_TYPE_ACCESS)
+		name = XATTR_NAME_POSIX_ACL_ACCESS;
+	else if (type == ACL_TYPE_DEFAULT)
+		name = XATTR_NAME_POSIX_ACL_DEFAULT;
+	else
+		return ERR_PTR(-EOPNOTSUPP);
+
+	value = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!value)
+		return ERR_PTR(-ENOMEM);
+	size = fuse_getxattr(inode, name, value, PAGE_SIZE);
+	if (size > 0)
+		acl = posix_acl_from_xattr(&init_user_ns, value, size);
+	else if ((size == 0) || (size == -ENODATA) ||
+		 (size == -EOPNOTSUPP && fc->no_getxattr))
+		acl = NULL;
+	else if (size == -ERANGE)
+		acl = ERR_PTR(-E2BIG);
+	else
+		acl = ERR_PTR(size);
+
+	kfree(value);
+	return acl;
+}
+
+int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	const char *name;
+	int ret;
+
+	if (!fc->posix_acl || fc->no_setxattr)
+		return -EOPNOTSUPP;
+
+	if (type == ACL_TYPE_ACCESS)
+		name = XATTR_NAME_POSIX_ACL_ACCESS;
+	else if (type == ACL_TYPE_DEFAULT)
+		name = XATTR_NAME_POSIX_ACL_DEFAULT;
+	else
+		return -EINVAL;
+
+	if (acl) {
+		/*
+		 * Fuse userspace is responsible for updating access
+		 * permissions in the inode, if needed. fuse_setxattr
+		 * invalidates the inode attributes, which will force
+		 * them to be refreshed the next time they are used,
+		 * and it also updates i_ctime.
+		 */
+		size_t size = posix_acl_xattr_size(acl->a_count);
+		void *value;
+
+		if (size > PAGE_SIZE)
+			return -E2BIG;
+
+		value = kmalloc(size, GFP_KERNEL);
+		if (!value)
+			return -ENOMEM;
+
+		ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
+		if (ret < 0) {
+			kfree(value);
+			return ret;
+		}
+
+		ret = fuse_setxattr(inode, name, value, size, 0);
+		kfree(value);
+	} else {
+		ret = fuse_removexattr(inode, name);
+	}
+	forget_all_cached_acls(inode);
+	fuse_invalidate_attr(inode);
+
+	return ret;
+}
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 7cb68b18eb3f..3076f48d86a6 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -14,6 +14,7 @@
 #include <linux/namei.h>
 #include <linux/slab.h>
 #include <linux/xattr.h>
+#include <linux/posix_acl.h>
 
 static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx)
 {
@@ -244,6 +245,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 		if (ret || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
 			goto invalid;
 
+		forget_all_cached_acls(inode);
 		fuse_change_attributes(inode, &outarg.attr,
 				       entry_attr_timeout(&outarg),
 				       attr_version);
@@ -918,6 +920,7 @@ int fuse_update_attributes(struct inode *inode, struct kstat *stat,
 
 	if (time_before64(fi->i_time, get_jiffies_64())) {
 		r = true;
+		forget_all_cached_acls(inode);
 		err = fuse_do_getattr(inode, stat, file);
 	} else {
 		r = false;
@@ -1065,6 +1068,7 @@ static int fuse_perm_getattr(struct inode *inode, int mask)
 	if (mask & MAY_NOT_BLOCK)
 		return -ECHILD;
 
+	forget_all_cached_acls(inode);
 	return fuse_do_getattr(inode, NULL, NULL);
 }
 
@@ -1234,6 +1238,7 @@ retry:
 		fi->nlookup++;
 		spin_unlock(&fc->lock);
 
+		forget_all_cached_acls(inode);
 		fuse_change_attributes(inode, &o->attr,
 				       entry_attr_timeout(o),
 				       attr_version);
@@ -1748,6 +1753,13 @@ static int fuse_setattr(struct dentry *entry, struct iattr *attr)
 
 	ret = fuse_do_setattr(inode, attr, file);
 	if (!ret) {
+		/*
+		 * If filesystem supports acls it may have updated acl xattrs in
+		 * the filesystem, so forget cached acls for the inode.
+		 */
+		if (fc->posix_acl)
+			forget_all_cached_acls(inode);
+
 		/* Directory mode changed, may need to revalidate access */
 		if (d_is_dir(entry) && (attr->ia_valid & ATTR_MODE))
 			fuse_invalidate_entry_cache(entry);
@@ -1785,6 +1797,8 @@ static const struct inode_operations fuse_dir_inode_operations = {
 	.getxattr	= generic_getxattr,
 	.listxattr	= fuse_listxattr,
 	.removexattr	= generic_removexattr,
+	.get_acl	= fuse_get_acl,
+	.set_acl	= fuse_set_acl,
 };
 
 static const struct file_operations fuse_dir_operations = {
@@ -1806,6 +1820,8 @@ static const struct inode_operations fuse_common_inode_operations = {
 	.getxattr	= generic_getxattr,
 	.listxattr	= fuse_listxattr,
 	.removexattr	= generic_removexattr,
+	.get_acl	= fuse_get_acl,
+	.set_acl	= fuse_set_acl,
 };
 
 static const struct inode_operations fuse_symlink_inode_operations = {
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 9940a648c985..e8d96ec22533 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -23,6 +23,7 @@
 #include <linux/poll.h>
 #include <linux/workqueue.h>
 #include <linux/kref.h>
+#include <linux/xattr.h>
 
 /** Max number of pages that can be used in a single read request */
 #define FUSE_MAX_PAGES_PER_REQ 32
@@ -627,6 +628,9 @@ struct fuse_conn {
 	/** Is lseek not implemented by fs? */
 	unsigned no_lseek:1;
 
+	/** Does the filesystem support posix acls? */
+	unsigned posix_acl:1;
+
 	/** The number of requests waiting for completion */
 	atomic_t num_waiting;
 
@@ -971,7 +975,17 @@ void fuse_set_initialized(struct fuse_conn *fc);
 void fuse_unlock_inode(struct inode *inode);
 void fuse_lock_inode(struct inode *inode);
 
+int fuse_setxattr(struct inode *inode, const char *name, const void *value,
+		  size_t size, int flags);
+ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
+		      size_t size);
 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
+int fuse_removexattr(struct inode *inode, const char *name);
 extern const struct xattr_handler *fuse_xattr_handlers[];
+extern const struct xattr_handler *fuse_acl_xattr_handlers[];
+
+struct posix_acl;
+struct posix_acl *fuse_get_acl(struct inode *inode, int type);
+int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 
 #endif /* _FS_FUSE_I_H */
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index b965934939cb..16ac9d86c507 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -20,6 +20,7 @@
 #include <linux/random.h>
 #include <linux/sched.h>
 #include <linux/exportfs.h>
+#include <linux/posix_acl.h>
 
 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
 MODULE_DESCRIPTION("Filesystem in Userspace");
@@ -340,6 +341,7 @@ int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 		return -ENOENT;
 
 	fuse_invalidate_attr(inode);
+	forget_all_cached_acls(inode);
 	if (offset >= 0) {
 		pg_start = offset >> PAGE_SHIFT;
 		if (len <= 0)
@@ -914,6 +916,11 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 				fc->handle_killpriv = 1;
 			if (arg->time_gran && arg->time_gran <= 1000000000)
 				fc->sb->s_time_gran = arg->time_gran;
+			if ((arg->flags & FUSE_POSIX_ACL)) {
+				fc->flags |= FUSE_DEFAULT_PERMISSIONS;
+				fc->posix_acl = 1;
+				fc->sb->s_xattr = fuse_acl_xattr_handlers;
+			}
 		} else {
 			ra_pages = fc->max_read / PAGE_SIZE;
 			fc->no_lock = 1;
@@ -943,7 +950,7 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 		FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
 		FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
 		FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
-		FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV;
+		FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL;
 	req->in.h.opcode = FUSE_INIT;
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(*arg);
diff --git a/fs/fuse/xattr.c b/fs/fuse/xattr.c
index e22980f0a9e2..04b097f29d8a 100644
--- a/fs/fuse/xattr.c
+++ b/fs/fuse/xattr.c
@@ -9,9 +9,10 @@
 #include "fuse_i.h"
 
 #include <linux/xattr.h>
+#include <linux/posix_acl_xattr.h>
 
-static int fuse_setxattr(struct inode *inode, const char *name,
-			 const void *value, size_t size, int flags)
+int fuse_setxattr(struct inode *inode, const char *name, const void *value,
+		  size_t size, int flags)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	FUSE_ARGS(args);
@@ -45,8 +46,8 @@ static int fuse_setxattr(struct inode *inode, const char *name,
 	return err;
 }
 
-static ssize_t fuse_getxattr(struct inode *inode, const char *name,
-			     void *value, size_t size)
+ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
+		      size_t size)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	FUSE_ARGS(args);
@@ -147,7 +148,7 @@ ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size)
 	return ret;
 }
 
-static int fuse_removexattr(struct inode *inode, const char *name)
+int fuse_removexattr(struct inode *inode, const char *name)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	FUSE_ARGS(args);
@@ -201,3 +202,10 @@ const struct xattr_handler *fuse_xattr_handlers[] = {
 	&fuse_xattr_handler,
 	NULL
 };
+
+const struct xattr_handler *fuse_acl_xattr_handlers[] = {
+	&posix_acl_access_xattr_handler,
+	&posix_acl_default_xattr_handler,
+	&fuse_xattr_handler,
+	NULL
+};
diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index 14ca2f10d354..42fa977e3b14 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -111,6 +111,7 @@
  *
  *  7.26
  *  - add FUSE_HANDLE_KILLPRIV
+ *  - add FUSE_POSIX_ACL
  */
 
 #ifndef _LINUX_FUSE_H
@@ -242,6 +243,7 @@ struct fuse_file_lock {
  * FUSE_NO_OPEN_SUPPORT: kernel supports zero-message opens
  * FUSE_PARALLEL_DIROPS: allow parallel lookups and readdir
  * FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on write/chown/trunc
+ * FUSE_POSIX_ACL: filesystem supports posix acls
  */
 #define FUSE_ASYNC_READ		(1 << 0)
 #define FUSE_POSIX_LOCKS	(1 << 1)
@@ -263,6 +265,7 @@ struct fuse_file_lock {
 #define FUSE_NO_OPEN_SUPPORT	(1 << 17)
 #define FUSE_PARALLEL_DIROPS    (1 << 18)
 #define FUSE_HANDLE_KILLPRIV	(1 << 19)
+#define FUSE_POSIX_ACL		(1 << 20)
 
 /**
  * CUSE INIT request/reply flags