[RFC PATCH 14/17] zuf: xattr implementation

[Boaz harrosh <boaz@plexistor.com>]

From: Boaz Harrosh <boazh@netapp.com>

We establish the usual dispatch to user-mode. For get and
set. Since the buffers are variable length we utilize the
zdo->overflow_handler for the extra copy from Server.
(see also zuf-core.c)

Signed-off-by: Boaz Harrosh <boazh@netapp.com>
---
 fs/zuf/Makefile   |   1 +
 fs/zuf/_extern.h  |  10 ++
 fs/zuf/_pr.h      |   1 +
 fs/zuf/file.c     |   1 +
 fs/zuf/inode.c    |   3 +-
 fs/zuf/namei.c    |   2 +
 fs/zuf/super.c    |   1 +
 fs/zuf/symlink.c  |   1 +
 fs/zuf/xattr.c    | 314 ++++++++++++++++++++++++++++++++++++++++++++++
 fs/zuf/zuf-core.c |   3 +
 fs/zuf/zuf.h      |   7 ++
 fs/zuf/zus_api.h  |  22 ++++
 12 files changed, 365 insertions(+), 1 deletion(-)
 create mode 100644 fs/zuf/xattr.c

diff --git a/fs/zuf/Makefile b/fs/zuf/Makefile
index 5304aba901b2..5d638760a82f 100644
--- a/fs/zuf/Makefile
+++ b/fs/zuf/Makefile
@@ -17,6 +17,7 @@ zuf-y += md.o t1.o t2.o
 zuf-y += zuf-core.o zuf-root.o
 
 # Main FS
+zuf-y += xattr.o
 zuf-y += rw.o mmap.o ioctl.o
 zuf-y += super.o inode.o directory.o namei.o file.o symlink.o
 zuf-y += module.o
diff --git a/fs/zuf/_extern.h b/fs/zuf/_extern.h
index b8e24c6a66d9..1f4b39911a5d 100644
--- a/fs/zuf/_extern.h
+++ b/fs/zuf/_extern.h
@@ -73,6 +73,16 @@ int zuf_iom_execute_async(struct super_block *sb, struct zus_iomap_build *iomb,
 /* file.c */
 int zuf_isync(struct inode *inode, loff_t start, loff_t end, int datasync);
 
+/* xattr.c */
+int zuf_initxattrs(struct inode *inode, const struct xattr *xattr_array,
+		   void *fs_info);
+ssize_t __zuf_getxattr(struct inode *inode, int type, const char *name,
+		       void *buffer, size_t size);
+int __zuf_setxattr(struct inode *inode, int type, const char *name,
+		   const void *value, size_t size, int flags);
+ssize_t zuf_listxattr(struct dentry *dentry, char *buffer, size_t size);
+extern const struct xattr_handler *zuf_xattr_handlers[];
+
 
 /* super.c */
 int zuf_init_inodecache(void);
diff --git a/fs/zuf/_pr.h b/fs/zuf/_pr.h
index a1ceab2abce2..04b99f57f2b5 100644
--- a/fs/zuf/_pr.h
+++ b/fs/zuf/_pr.h
@@ -42,6 +42,7 @@
 #define zuf_dbg_vfs(s, args ...)	zuf_chan_debug("vfs  ", s, ##args)
 #define zuf_dbg_rw(s, args ...)		zuf_chan_debug("rw   ", s, ##args)
 #define zuf_dbg_t1(s, args ...)		zuf_chan_debug("t1   ", s, ##args)
+#define zuf_dbg_xattr(s, args ...)	zuf_chan_debug("xattr", s, ##args)
 #define zuf_dbg_t2(s, args ...)		zuf_chan_debug("t2dbg", s, ##args)
 #define zuf_dbg_t2_rw(s, args ...)	zuf_chan_debug("t2grw", s, ##args)
 #define zuf_dbg_core(s, args ...)	zuf_chan_debug("core ", s, ##args)
diff --git a/fs/zuf/file.c b/fs/zuf/file.c
index 48b339cb5f8f..814a75105321 100644
--- a/fs/zuf/file.c
+++ b/fs/zuf/file.c
@@ -521,4 +521,5 @@ const struct inode_operations zuf_file_inode_operations = {
 	.getattr	= zuf_getattr,
 	.update_time	= zuf_update_time,
 	.fiemap		= tozu_fiemap,
+	.listxattr	= zuf_listxattr,
 };
diff --git a/fs/zuf/inode.c b/fs/zuf/inode.c
index 8f9b4f28c556..73f94e7062e5 100644
--- a/fs/zuf/inode.c
+++ b/fs/zuf/inode.c
@@ -361,7 +361,8 @@ struct inode *zuf_new_inode(struct inode *dir, umode_t mode,
 
 	zuf_dbg_verbose("inode=%p name=%s\n", inode, qstr->name);
 
-	err = security_inode_init_security(inode, dir, qstr, NULL, NULL);
+	err = security_inode_init_security(inode, dir, qstr, zuf_initxattrs,
+					   NULL);
 	if (err && err != -EOPNOTSUPP)
 		goto fail;
 
diff --git a/fs/zuf/namei.c b/fs/zuf/namei.c
index e78aa04f10d5..803069423674 100644
--- a/fs/zuf/namei.c
+++ b/fs/zuf/namei.c
@@ -420,10 +420,12 @@ const struct inode_operations zuf_dir_inode_operations = {
 	.setattr	= zuf_setattr,
 	.getattr	= zuf_getattr,
 	.update_time	= zuf_update_time,
+	.listxattr	= zuf_listxattr,
 };
 
 const struct inode_operations zuf_special_inode_operations = {
 	.setattr	= zuf_setattr,
 	.getattr	= zuf_getattr,
 	.update_time	= zuf_update_time,
+	.listxattr	= zuf_listxattr,
 };
diff --git a/fs/zuf/super.c b/fs/zuf/super.c
index 2f1dd44290a2..588558066333 100644
--- a/fs/zuf/super.c
+++ b/fs/zuf/super.c
@@ -414,6 +414,7 @@ static int zuf_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_flags |= MS_NOSEC | (ioc_mount->zmi.acl_on ? SB_POSIXACL : 0);
 
 	sb->s_op = &zuf_sops;
+	sb->s_xattr = zuf_xattr_handlers;
 
 	root_i = zuf_iget(sb, ioc_mount->zmi.zus_ii, ioc_mount->zmi._zi,
 			  &exist);
diff --git a/fs/zuf/symlink.c b/fs/zuf/symlink.c
index 1446bdf60cb9..5e9115ba4cbd 100644
--- a/fs/zuf/symlink.c
+++ b/fs/zuf/symlink.c
@@ -70,4 +70,5 @@ const struct inode_operations zuf_symlink_inode_operations = {
 	.update_time	= zuf_update_time,
 	.setattr	= zuf_setattr,
 	.getattr	= zuf_getattr,
+	.listxattr	= zuf_listxattr,
 };
diff --git a/fs/zuf/xattr.c b/fs/zuf/xattr.c
new file mode 100644
index 000000000000..6aae297c09e3
--- /dev/null
+++ b/fs/zuf/xattr.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Extended Attributes
+ *
+ * Copyright (c) 2018 NetApp Inc. All rights reserved.
+ *
+ * ZUFS-License: GPL-2.0. See module.c for LICENSE details.
+ *
+ * Authors:
+ *	Boaz Harrosh <boazh@netapp.com>
+ */
+
+#include <linux/fs.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+#include "zuf.h"
+
+/* ~~~~~~~~~~~~~~~ xattr get ~~~~~~~~~~~~~~~ */
+
+struct _xxxattr {
+	void *user_buffer;
+	union {
+		struct zufs_ioc_xattr ioc_xattr;
+		char buf[512];
+	} d;
+};
+
+static inline uint _XXXATTR_SIZE(uint ioc_size)
+{
+	struct _xxxattr *_xxxattr;
+
+	return ioc_size + (sizeof(*_xxxattr) - sizeof(_xxxattr->d));
+}
+
+static int _xattr_oh(struct zuf_dispatch_op *zdo, void *parg, ulong max_bytes)
+{
+	struct zufs_ioc_hdr *hdr = zdo->hdr;
+	struct zufs_ioc_xattr *ioc_xattr =
+			container_of(hdr, typeof(*ioc_xattr), hdr);
+	struct _xxxattr *_xxattr =
+			container_of(ioc_xattr, typeof(*_xxattr), d.ioc_xattr);
+	struct zufs_ioc_xattr *user_ioc_xattr = parg;
+
+	if (hdr->err)
+		return 0;
+
+	ioc_xattr->user_buf_size = user_ioc_xattr->user_buf_size;
+
+	hdr->out_len -= sizeof(ioc_xattr->user_buf_size);
+	memcpy(_xxattr->user_buffer, user_ioc_xattr->buf, hdr->out_len);
+	return 0;
+}
+
+ssize_t __zuf_getxattr(struct inode *inode, int type, const char *name,
+		       void *buffer, size_t size)
+{
+	size_t name_len = strlen(name) + 1; /* plus \NUL */
+	struct _xxxattr *p_xattr;
+	struct _xxxattr s_xattr;
+	enum big_alloc_type bat;
+	struct zufs_ioc_xattr *ioc_xattr;
+	size_t ioc_size = sizeof(*ioc_xattr) + name_len;
+	struct zuf_dispatch_op zdo;
+	int err;
+	ssize_t ret;
+
+	zuf_dbg_vfs("[%ld] type=%d name=%s size=%lu ioc_size=%lu\n",
+			inode->i_ino, type, name, size, ioc_size);
+
+	p_xattr = big_alloc(_XXXATTR_SIZE(ioc_size), sizeof(s_xattr), &s_xattr,
+			    GFP_KERNEL, &bat);
+	if (unlikely(!p_xattr))
+		return -ENOMEM;
+
+	ioc_xattr = &p_xattr->d.ioc_xattr;
+	memset(ioc_xattr, 0, sizeof(*ioc_xattr));
+	p_xattr->user_buffer = buffer;
+
+	ioc_xattr->hdr.in_len = ioc_size;
+	ioc_xattr->hdr.out_start =
+				offsetof(struct zufs_ioc_xattr, user_buf_size);
+	 /* out_len updated by zus */
+	ioc_xattr->hdr.out_len = sizeof(ioc_xattr->user_buf_size);
+	ioc_xattr->hdr.out_max = 0;
+	ioc_xattr->hdr.operation = ZUFS_OP_XATTR_GET;
+	ioc_xattr->zus_ii = ZUII(inode)->zus_ii;
+	ioc_xattr->type = type;
+	ioc_xattr->name_len = name_len;
+	ioc_xattr->user_buf_size = size;
+
+	strcpy(ioc_xattr->buf, name);
+
+	zuf_dispatch_init(&zdo, &ioc_xattr->hdr, NULL, 0);
+	zdo.oh = _xattr_oh;
+	err = __zufc_dispatch(ZUF_ROOT(SBI(inode->i_sb)), &zdo);
+	ret = ioc_xattr->user_buf_size;
+
+	big_free(p_xattr, bat);
+
+	if (unlikely(err))
+		return err;
+
+	return ret;
+}
+
+/* ~~~~~~~~~~~~~~~ xattr set ~~~~~~~~~~~~~~~ */
+
+int __zuf_setxattr(struct inode *inode, int type, const char *name,
+		   const void *value, size_t size, int flags)
+{
+	size_t name_len = strlen(name) + 1;
+	struct _xxxattr *p_xattr;
+	struct _xxxattr s_xattr;
+	enum big_alloc_type bat;
+	struct zufs_ioc_xattr *ioc_xattr;
+	size_t ioc_size = sizeof(*ioc_xattr) + name_len + size;
+	int err;
+
+	zuf_dbg_vfs("[%ld] type=%d name=%s size=%lu ioc_size=%lu\n",
+			inode->i_ino, type, name, size, ioc_size);
+
+	p_xattr = big_alloc(_XXXATTR_SIZE(ioc_size), sizeof(s_xattr), &s_xattr,
+			    GFP_KERNEL, &bat);
+	if (unlikely(!p_xattr))
+		return -ENOMEM;
+
+	ioc_xattr = &p_xattr->d.ioc_xattr;
+	memset(ioc_xattr, 0, sizeof(*ioc_xattr));
+
+	ioc_xattr->hdr.in_len = ioc_size;
+	ioc_xattr->hdr.out_len = 0;
+	ioc_xattr->hdr.operation = ZUFS_OP_XATTR_SET;
+	ioc_xattr->zus_ii = ZUII(inode)->zus_ii;
+	ioc_xattr->type = type;
+	ioc_xattr->name_len = name_len;
+	ioc_xattr->user_buf_size = size;
+	ioc_xattr->flags = flags;
+
+	if (value && !size)
+		ioc_xattr->ioc_flags = ZUFS_XATTR_SET_EMPTY;
+
+	strcpy(ioc_xattr->buf, name);
+	if (value)
+		memcpy(ioc_xattr->buf + name_len, value, size);
+
+	err = zufc_dispatch(ZUF_ROOT(SBI(inode->i_sb)), &ioc_xattr->hdr,
+			    NULL, 0);
+
+	big_free(p_xattr, bat);
+
+	return err;
+}
+
+/* ~~~~~~~~~~~~~~~ xattr list ~~~~~~~~~~~~~~~ */
+
+static ssize_t __zuf_listxattr(struct inode *inode, char *buffer, size_t size)
+{
+	struct zuf_inode_info *zii = ZUII(inode);
+	struct _xxxattr s_xattr;
+	struct zufs_ioc_xattr *ioc_xattr;
+	struct zuf_dispatch_op zdo;
+
+	int err;
+
+	zuf_dbg_vfs("[%ld] size=%lu\n", inode->i_ino, size);
+
+	ioc_xattr = &s_xattr.d.ioc_xattr;
+	memset(ioc_xattr, 0, sizeof(*ioc_xattr));
+	s_xattr.user_buffer = buffer;
+
+	ioc_xattr->hdr.in_len = sizeof(*ioc_xattr);
+	ioc_xattr->hdr.out_start =
+				offsetof(struct zufs_ioc_xattr, user_buf_size);
+	 /* out_len updated by zus */
+	ioc_xattr->hdr.out_len = sizeof(ioc_xattr->user_buf_size);
+	ioc_xattr->hdr.out_max = 0;
+	ioc_xattr->hdr.operation = ZUFS_OP_XATTR_LIST;
+	ioc_xattr->zus_ii = zii->zus_ii;
+	ioc_xattr->name_len = 0;
+	ioc_xattr->user_buf_size = size;
+	ioc_xattr->ioc_flags = capable(CAP_SYS_ADMIN) ? ZUFS_XATTR_TRUSTED : 0;
+
+	zuf_dispatch_init(&zdo, &ioc_xattr->hdr, NULL, 0);
+	zdo.oh = _xattr_oh;
+	err = __zufc_dispatch(ZUF_ROOT(SBI(inode->i_sb)), &zdo);
+	if (unlikely(err))
+		return err;
+
+	return ioc_xattr->user_buf_size;
+}
+
+ssize_t zuf_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+	struct inode *inode = dentry->d_inode;
+	struct zuf_inode_info *zii = ZUII(inode);
+	ssize_t ret;
+
+	zuf_smr_lock(zii);
+
+	ret = __zuf_listxattr(inode, buffer, size);
+
+	zuf_smr_unlock(zii);
+
+	return ret;
+}
+
+/* ~~~~~~~~~~~~~~~ xattr sb handlers ~~~~~~~~~~~~~~~ */
+static bool zuf_xattr_handler_list(struct dentry *dentry)
+{
+	return true;
+}
+
+static
+int zuf_xattr_handler_get(const struct xattr_handler *handler,
+			  struct dentry *dentry, struct inode *inode,
+			  const char *name, void *value, size_t size)
+{
+	struct zuf_inode_info *zii = ZUII(inode);
+	int ret;
+
+	zuf_dbg_xattr("[%ld] name=%s\n", inode->i_ino, name);
+
+	zuf_smr_lock(zii);
+
+	ret = __zuf_getxattr(inode, handler->flags, name, value, size);
+
+	zuf_smr_unlock(zii);
+
+	return ret;
+}
+
+static
+int zuf_xattr_handler_set(const struct xattr_handler *handler,
+			  struct dentry *d_notused, struct inode *inode,
+			  const char *name, const void *value, size_t size,
+			  int flags)
+{
+	struct zuf_inode_info *zii = ZUII(inode);
+	int err;
+
+	zuf_dbg_xattr("[%ld] name=%s size=0x%lx flags=0x%x\n",
+			inode->i_ino, name, size, flags);
+
+	zuf_smw_lock(zii);
+
+	err = __zuf_setxattr(inode, handler->flags, name, value, size, flags);
+
+	zuf_smw_unlock(zii);
+
+	return err;
+}
+
+const struct xattr_handler zuf_xattr_security_handler = {
+	.prefix	= XATTR_SECURITY_PREFIX,
+	.flags = ZUF_XF_SECURITY,
+	.list	= zuf_xattr_handler_list,
+	.get	= zuf_xattr_handler_get,
+	.set	= zuf_xattr_handler_set,
+};
+
+const struct xattr_handler zuf_xattr_trusted_handler = {
+	.prefix	= XATTR_TRUSTED_PREFIX,
+	.flags = ZUF_XF_TRUSTED,
+	.list	= zuf_xattr_handler_list,
+	.get	= zuf_xattr_handler_get,
+	.set	= zuf_xattr_handler_set,
+};
+
+const struct xattr_handler zuf_xattr_user_handler = {
+	.prefix	= XATTR_USER_PREFIX,
+	.flags = ZUF_XF_USER,
+	.list	= zuf_xattr_handler_list,
+	.get	= zuf_xattr_handler_get,
+	.set	= zuf_xattr_handler_set,
+};
+
+const struct xattr_handler *zuf_xattr_handlers[] = {
+	&zuf_xattr_user_handler,
+	&zuf_xattr_trusted_handler,
+	&zuf_xattr_security_handler,
+	&posix_acl_access_xattr_handler,
+	&posix_acl_default_xattr_handler,
+	NULL
+};
+
+/*
+ * Callback for security_inode_init_security() for acquiring xattrs.
+ */
+int zuf_initxattrs(struct inode *inode, const struct xattr *xattr_array,
+		   void *fs_info)
+{
+	const struct xattr *xattr;
+
+	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+		int err;
+
+		/* REMOVEME: We had a BUG here for a long time that never
+		 * crashed, I want to see this is called, please.
+		 */
+		zuf_warn("Yes it is name=%s value-size=%zd\n",
+			  xattr->name, xattr->value_len);
+
+		err = zuf_xattr_handler_set(&zuf_xattr_security_handler, NULL,
+					    inode, xattr->name, xattr->value,
+					    xattr->value_len, 0);
+		if (unlikely(err)) {
+			zuf_err("[%ld] failed to init xattrs err=%d\n",
+				 inode->i_ino, err);
+			return err;
+		}
+	}
+	return 0;
+}
diff --git a/fs/zuf/zuf-core.c b/fs/zuf/zuf-core.c
index 09ad210318f8..c6b614465ab3 100644
--- a/fs/zuf/zuf-core.c
+++ b/fs/zuf/zuf-core.c
@@ -788,6 +788,9 @@ const char *zuf_op_name(enum e_zufs_operation op)
 		CASE_ENUM_NAME(ZUFS_OP_FALLOCATE	);
 		CASE_ENUM_NAME(ZUFS_OP_LLSEEK		);
 		CASE_ENUM_NAME(ZUFS_OP_IOCTL		);
+		CASE_ENUM_NAME(ZUFS_OP_XATTR_GET	);
+		CASE_ENUM_NAME(ZUFS_OP_XATTR_SET	);
+		CASE_ENUM_NAME(ZUFS_OP_XATTR_LIST	);
 		CASE_ENUM_NAME(ZUFS_OP_BREAK		);
 	default:
 		return "UNKNOWN";
diff --git a/fs/zuf/zuf.h b/fs/zuf/zuf.h
index 98f4ea088671..13b246189d8b 100644
--- a/fs/zuf/zuf.h
+++ b/fs/zuf/zuf.h
@@ -328,6 +328,13 @@ static inline void *zuf_dpp_t_addr(struct super_block *sb, zu_dpp_t v)
 	return md_addr_verify(SBI(sb)->md, zu_dpp_t_val(v));
 }
 
+/* xattr types */
+enum {	ZUF_XF_SECURITY    = 1,
+	ZUF_XF_SYSTEM      = 2,
+	ZUF_XF_TRUSTED     = 3,
+	ZUF_XF_USER        = 4,
+};
+
 enum big_alloc_type { ba_stack, ba_kmalloc, ba_vmalloc };
 
 static inline
diff --git a/fs/zuf/zus_api.h b/fs/zuf/zus_api.h
index f32ee615b937..40f369d20306 100644
--- a/fs/zuf/zus_api.h
+++ b/fs/zuf/zus_api.h
@@ -351,6 +351,9 @@ enum e_zufs_operation {
 	ZUFS_OP_FALLOCATE,
 	ZUFS_OP_LLSEEK,
 	ZUFS_OP_IOCTL,
+	ZUFS_OP_XATTR_GET,
+	ZUFS_OP_XATTR_SET,
+	ZUFS_OP_XATTR_LIST,
 
 	ZUFS_OP_BREAK,		/* Kernel telling Server to exit */
 	ZUFS_OP_MAX_OPT,
@@ -602,6 +605,25 @@ struct zufs_ioc_ioctl {
 	};
 };
 
+/* xattr ioc_flags */
+#define ZUFS_XATTR_SET_EMPTY	(1 << 0)
+#define ZUFS_XATTR_TRUSTED	(1 << 1)
+
+/* ZUFS_OP_XATTR */
+struct zufs_ioc_xattr {
+	struct zufs_ioc_hdr hdr;
+	/* IN */
+	struct zus_inode_info *zus_ii;
+	__u32	flags;
+	__u32	type;
+	__u16	name_len;
+	__u16	ioc_flags;
+
+	/* OUT */
+	__u32	user_buf_size;
+	char	buf[0];
+} __packed;
+
 /* ~~~~ io_map structures && IOCTL(s) ~~~~ */
 /*
  * These set of structures and helpers are used in return of zufs_ioc_IO and
-- 
2.20.1