From 6038f373a3dc1f1c26496e60b6c40b164716f07e Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Sun, 15 Aug 2010 18:52:59 +0200
Subject: llseek: automatically add .llseek fop

All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
---
 drivers/xen/xenfs/super.c  | 1 +
 drivers/xen/xenfs/xenbus.c | 1 +
 2 files changed, 2 insertions(+)

(limited to 'drivers/xen/xenfs')

diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index 78bfab0700ba..bd96340063c1 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -35,6 +35,7 @@ static ssize_t capabilities_read(struct file *file, char __user *buf,
 
 static const struct file_operations capabilities_file_ops = {
 	.read = capabilities_read,
+	.llseek = default_llseek,
 };
 
 static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
diff --git a/drivers/xen/xenfs/xenbus.c b/drivers/xen/xenfs/xenbus.c
index 3b39c3752e21..1c1236087f78 100644
--- a/drivers/xen/xenfs/xenbus.c
+++ b/drivers/xen/xenfs/xenbus.c
@@ -594,4 +594,5 @@ const struct file_operations xenbus_file_ops = {
 	.open = xenbus_file_open,
 	.release = xenbus_file_release,
 	.poll = xenbus_file_poll,
+	.llseek = no_llseek,
 };
-- 
cgit v1.2.3


From fc14f2fef682df677d64a145256dbd263df2aa7b Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun, 25 Jul 2010 01:48:30 +0400
Subject: convert get_sb_single() users

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/powerpc/platforms/cell/spufs/inode.c | 10 +++++-----
 arch/s390/hypfs/inode.c                   |  8 ++++----
 drivers/base/devtmpfs.c                   | 18 ++++++++---------
 drivers/infiniband/hw/ipath/ipath_fs.c    | 14 +++++++-------
 drivers/infiniband/hw/qib/qib_fs.c        | 14 +++++++-------
 drivers/isdn/capi/capifs.c                |  8 ++++----
 drivers/misc/ibmasm/ibmasmfs.c            |  9 ++++-----
 drivers/oprofile/oprofilefs.c             |  8 ++++----
 drivers/usb/core/inode.c                  |  8 ++++----
 drivers/usb/gadget/f_fs.c                 | 14 +++++++-------
 drivers/usb/gadget/inode.c                | 10 +++++-----
 drivers/xen/xenfs/super.c                 |  8 ++++----
 fs/binfmt_misc.c                          |  8 ++++----
 fs/configfs/mount.c                       |  8 ++++----
 fs/debugfs/inode.c                        |  8 ++++----
 fs/devpts/inode.c                         | 32 +++++++++++++++----------------
 fs/fuse/control.c                         | 10 ++++------
 fs/nfsd/nfsctl.c                          |  8 ++++----
 fs/openpromfs/inode.c                     |  8 ++++----
 fs/super.c                                | 25 ++++++++++++++++++------
 include/linux/fs.h                        |  3 +++
 net/sunrpc/rpc_pipe.c                     | 18 ++++++++---------
 security/inode.c                          |  8 ++++----
 security/selinux/selinuxfs.c              |  9 ++++-----
 security/smack/smackfs.c                  | 12 +++++-------
 25 files changed, 147 insertions(+), 139 deletions(-)

(limited to 'drivers/xen/xenfs')

diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 5dec408d6703..3532b92de983 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -798,17 +798,17 @@ spufs_fill_super(struct super_block *sb, void *data, int silent)
 	return spufs_create_root(sb, data);
 }
 
-static int
-spufs_get_sb(struct file_system_type *fstype, int flags,
-		const char *name, void *data, struct vfsmount *mnt)
+static struct dentry *
+spufs_mount(struct file_system_type *fstype, int flags,
+		const char *name, void *data)
 {
-	return get_sb_single(fstype, flags, data, spufs_fill_super, mnt);
+	return mount_single(fstype, flags, data, spufs_fill_super);
 }
 
 static struct file_system_type spufs_type = {
 	.owner = THIS_MODULE,
 	.name = "spufs",
-	.get_sb = spufs_get_sb,
+	.mount = spufs_mount,
 	.kill_sb = kill_litter_super,
 };
 
diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index 74d98670be27..47cc446dab8f 100644
--- a/arch/s390/hypfs/inode.c
+++ b/arch/s390/hypfs/inode.c
@@ -316,10 +316,10 @@ static int hypfs_fill_super(struct super_block *sb, void *data, int silent)
 	return 0;
 }
 
-static int hypfs_get_super(struct file_system_type *fst, int flags,
-			const char *devname, void *data, struct vfsmount *mnt)
+static struct dentry *hypfs_mount(struct file_system_type *fst, int flags,
+			const char *devname, void *data)
 {
-	return get_sb_single(fst, flags, data, hypfs_fill_super, mnt);
+	return mount_single(fst, flags, data, hypfs_fill_super);
 }
 
 static void hypfs_kill_super(struct super_block *sb)
@@ -455,7 +455,7 @@ static const struct file_operations hypfs_file_ops = {
 static struct file_system_type hypfs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "s390_hypfs",
-	.get_sb		= hypfs_get_super,
+	.mount		= hypfs_mount,
 	.kill_sb	= hypfs_kill_super
 };
 
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index af0600143d1c..82bbb5967aa9 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -29,33 +29,33 @@
 static struct vfsmount *dev_mnt;
 
 #if defined CONFIG_DEVTMPFS_MOUNT
-static int dev_mount = 1;
+static int mount_dev = 1;
 #else
-static int dev_mount;
+static int mount_dev;
 #endif
 
 static DEFINE_MUTEX(dirlock);
 
 static int __init mount_param(char *str)
 {
-	dev_mount = simple_strtoul(str, NULL, 0);
+	mount_dev = simple_strtoul(str, NULL, 0);
 	return 1;
 }
 __setup("devtmpfs.mount=", mount_param);
 
-static int dev_get_sb(struct file_system_type *fs_type, int flags,
-		      const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *dev_mount(struct file_system_type *fs_type, int flags,
+		      const char *dev_name, void *data)
 {
 #ifdef CONFIG_TMPFS
-	return get_sb_single(fs_type, flags, data, shmem_fill_super, mnt);
+	return mount_single(fs_type, flags, data, shmem_fill_super);
 #else
-	return get_sb_single(fs_type, flags, data, ramfs_fill_super, mnt);
+	return mount_single(fs_type, flags, data, ramfs_fill_super);
 #endif
 }
 
 static struct file_system_type dev_fs_type = {
 	.name = "devtmpfs",
-	.get_sb = dev_get_sb,
+	.mount = dev_mount,
 	.kill_sb = kill_litter_super,
 };
 
@@ -351,7 +351,7 @@ int devtmpfs_mount(const char *mntdir)
 {
 	int err;
 
-	if (!dev_mount)
+	if (!mount_dev)
 		return 0;
 
 	if (!dev_mnt)
diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c
index 12d5bf76302c..8c8afc716b98 100644
--- a/drivers/infiniband/hw/ipath/ipath_fs.c
+++ b/drivers/infiniband/hw/ipath/ipath_fs.c
@@ -362,13 +362,13 @@ bail:
 	return ret;
 }
 
-static int ipathfs_get_sb(struct file_system_type *fs_type, int flags,
-			const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *ipathfs_mount(struct file_system_type *fs_type,
+			int flags, const char *dev_name, void *data)
 {
-	int ret = get_sb_single(fs_type, flags, data,
-				    ipathfs_fill_super, mnt);
-	if (ret >= 0)
-		ipath_super = mnt->mnt_sb;
+	struct dentry *ret;
+	ret = mount_single(fs_type, flags, data, ipathfs_fill_super);
+	if (!IS_ERR(ret))
+		ipath_super = ret->d_sb;
 	return ret;
 }
 
@@ -411,7 +411,7 @@ bail:
 static struct file_system_type ipathfs_fs_type = {
 	.owner =	THIS_MODULE,
 	.name =		"ipathfs",
-	.get_sb =	ipathfs_get_sb,
+	.mount =	ipathfs_mount,
 	.kill_sb =	ipathfs_kill_super,
 };
 
diff --git a/drivers/infiniband/hw/qib/qib_fs.c b/drivers/infiniband/hw/qib/qib_fs.c
index 7e433d75c775..f99bddc01716 100644
--- a/drivers/infiniband/hw/qib/qib_fs.c
+++ b/drivers/infiniband/hw/qib/qib_fs.c
@@ -555,13 +555,13 @@ bail:
 	return ret;
 }
 
-static int qibfs_get_sb(struct file_system_type *fs_type, int flags,
-			const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *qibfs_mount(struct file_system_type *fs_type, int flags,
+			const char *dev_name, void *data)
 {
-	int ret = get_sb_single(fs_type, flags, data,
-				qibfs_fill_super, mnt);
-	if (ret >= 0)
-		qib_super = mnt->mnt_sb;
+	struct dentry *ret;
+	ret = mount_single(fs_type, flags, data, qibfs_fill_super);
+	if (!IS_ERR(ret))
+		qib_super = ret->d_sb;
 	return ret;
 }
 
@@ -603,7 +603,7 @@ int qibfs_remove(struct qib_devdata *dd)
 static struct file_system_type qibfs_fs_type = {
 	.owner =        THIS_MODULE,
 	.name =         "ipathfs",
-	.get_sb =       qibfs_get_sb,
+	.mount =        qibfs_mount,
 	.kill_sb =      qibfs_kill_super,
 };
 
diff --git a/drivers/isdn/capi/capifs.c b/drivers/isdn/capi/capifs.c
index 2b83850997c3..b4faed7fe0d3 100644
--- a/drivers/isdn/capi/capifs.c
+++ b/drivers/isdn/capi/capifs.c
@@ -125,16 +125,16 @@ fail:
 	return -ENOMEM;
 }
 
-static int capifs_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *capifs_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, capifs_fill_super, mnt);
+	return mount_single(fs_type, flags, data, capifs_fill_super);
 }
 
 static struct file_system_type capifs_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "capifs",
-	.get_sb		= capifs_get_sb,
+	.mount		= capifs_mount,
 	.kill_sb	= kill_anon_super,
 };
 
diff --git a/drivers/misc/ibmasm/ibmasmfs.c b/drivers/misc/ibmasm/ibmasmfs.c
index 0a53500636c9..d2d5d23416dd 100644
--- a/drivers/misc/ibmasm/ibmasmfs.c
+++ b/drivers/misc/ibmasm/ibmasmfs.c
@@ -91,11 +91,10 @@ static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root);
 static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent);
 
 
-static int ibmasmfs_get_super(struct file_system_type *fst,
-			int flags, const char *name, void *data,
-			struct vfsmount *mnt)
+static struct dentry *ibmasmfs_mount(struct file_system_type *fst,
+			int flags, const char *name, void *data)
 {
-	return get_sb_single(fst, flags, data, ibmasmfs_fill_super, mnt);
+	return mount_single(fst, flags, data, ibmasmfs_fill_super);
 }
 
 static const struct super_operations ibmasmfs_s_ops = {
@@ -108,7 +107,7 @@ static const struct file_operations *ibmasmfs_dir_ops = &simple_dir_operations;
 static struct file_system_type ibmasmfs_type = {
 	.owner          = THIS_MODULE,
 	.name           = "ibmasmfs",
-	.get_sb         = ibmasmfs_get_super,
+	.mount          = ibmasmfs_mount,
 	.kill_sb        = kill_litter_super,
 };
 
diff --git a/drivers/oprofile/oprofilefs.c b/drivers/oprofile/oprofilefs.c
index 449de59bf35b..e9ff6f7770be 100644
--- a/drivers/oprofile/oprofilefs.c
+++ b/drivers/oprofile/oprofilefs.c
@@ -259,17 +259,17 @@ static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent)
 }
 
 
-static int oprofilefs_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *oprofilefs_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, oprofilefs_fill_super, mnt);
+	return mount_single(fs_type, flags, data, oprofilefs_fill_super);
 }
 
 
 static struct file_system_type oprofilefs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "oprofilefs",
-	.get_sb		= oprofilefs_get_sb,
+	.mount		= oprofilefs_mount,
 	.kill_sb	= kill_litter_super,
 };
 
diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c
index e2f63c0ea09d..9819a4cc3b26 100644
--- a/drivers/usb/core/inode.c
+++ b/drivers/usb/core/inode.c
@@ -574,16 +574,16 @@ static void fs_remove_file (struct dentry *dentry)
 
 /* --------------------------------------------------------------------- */
 
-static int usb_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *usb_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, usbfs_fill_super, mnt);
+	return mount_single(fs_type, flags, data, usbfs_fill_super);
 }
 
 static struct file_system_type usb_fs_type = {
 	.owner =	THIS_MODULE,
 	.name =		"usbfs",
-	.get_sb =	usb_get_sb,
+	.mount =	usb_mount,
 	.kill_sb =	kill_litter_super,
 };
 
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index f276e9594f00..4a830df4fc31 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -1176,9 +1176,9 @@ invalid:
 
 /* "mount -t functionfs dev_name /dev/function" ends up here */
 
-static int
-ffs_fs_get_sb(struct file_system_type *t, int flags,
-	      const char *dev_name, void *opts, struct vfsmount *mnt)
+static struct dentry *
+ffs_fs_mount(struct file_system_type *t, int flags,
+	      const char *dev_name, void *opts)
 {
 	struct ffs_sb_fill_data data = {
 		.perms = {
@@ -1194,14 +1194,14 @@ ffs_fs_get_sb(struct file_system_type *t, int flags,
 
 	ret = functionfs_check_dev_callback(dev_name);
 	if (unlikely(ret < 0))
-		return ret;
+		return ERR_PTR(ret);
 
 	ret = ffs_fs_parse_opts(&data, opts);
 	if (unlikely(ret < 0))
-		return ret;
+		return ERR_PTR(ret);
 
 	data.dev_name = dev_name;
-	return get_sb_single(t, flags, &data, ffs_sb_fill, mnt);
+	return mount_single(t, flags, &data, ffs_sb_fill);
 }
 
 static void
@@ -1220,7 +1220,7 @@ ffs_fs_kill_sb(struct super_block *sb)
 static struct file_system_type ffs_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "functionfs",
-	.get_sb		= ffs_fs_get_sb,
+	.mount		= ffs_fs_mount,
 	.kill_sb	= ffs_fs_kill_sb,
 };
 
diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index ba145e7fbe03..3ed73f49cf18 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -2097,11 +2097,11 @@ enomem0:
 }
 
 /* "mount -t gadgetfs path /dev/gadget" ends up here */
-static int
-gadgetfs_get_sb (struct file_system_type *t, int flags,
-		const char *path, void *opts, struct vfsmount *mnt)
+static struct dentry *
+gadgetfs_mount (struct file_system_type *t, int flags,
+		const char *path, void *opts)
 {
-	return get_sb_single (t, flags, opts, gadgetfs_fill_super, mnt);
+	return mount_single (t, flags, opts, gadgetfs_fill_super);
 }
 
 static void
@@ -2119,7 +2119,7 @@ gadgetfs_kill_sb (struct super_block *sb)
 static struct file_system_type gadgetfs_type = {
 	.owner		= THIS_MODULE,
 	.name		= shortname,
-	.get_sb		= gadgetfs_get_sb,
+	.mount		= gadgetfs_mount,
 	.kill_sb	= gadgetfs_kill_sb,
 };
 
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index d6662b789b6b..f6339d11d59c 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -121,17 +121,17 @@ static int xenfs_fill_super(struct super_block *sb, void *data, int silent)
 	return rc;
 }
 
-static int xenfs_get_sb(struct file_system_type *fs_type,
+static int xenfs_mount(struct file_system_type *fs_type,
 			int flags, const char *dev_name,
-			void *data, struct vfsmount *mnt)
+			void *data)
 {
-	return get_sb_single(fs_type, flags, data, xenfs_fill_super, mnt);
+	return mount_single(fs_type, flags, data, xenfs_fill_super);
 }
 
 static struct file_system_type xenfs_type = {
 	.owner =	THIS_MODULE,
 	.name =		"xenfs",
-	.get_sb =	xenfs_get_sb,
+	.mount =	xenfs_mount,
 	.kill_sb =	kill_litter_super,
 };
 
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index 29990f0eee0c..1befe2ec8186 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -706,10 +706,10 @@ static int bm_fill_super(struct super_block * sb, void * data, int silent)
 	return err;
 }
 
-static int bm_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *bm_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, bm_fill_super, mnt);
+	return mount_single(fs_type, flags, data, bm_fill_super);
 }
 
 static struct linux_binfmt misc_format = {
@@ -720,7 +720,7 @@ static struct linux_binfmt misc_format = {
 static struct file_system_type bm_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "binfmt_misc",
-	.get_sb		= bm_get_sb,
+	.mount		= bm_mount,
 	.kill_sb	= kill_litter_super,
 };
 
diff --git a/fs/configfs/mount.c b/fs/configfs/mount.c
index 8c8d64230c2d..7d3607febe1c 100644
--- a/fs/configfs/mount.c
+++ b/fs/configfs/mount.c
@@ -104,16 +104,16 @@ static int configfs_fill_super(struct super_block *sb, void *data, int silent)
 	return 0;
 }
 
-static int configfs_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *configfs_do_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, configfs_fill_super, mnt);
+	return mount_single(fs_type, flags, data, configfs_fill_super);
 }
 
 static struct file_system_type configfs_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "configfs",
-	.get_sb		= configfs_get_sb,
+	.mount		= configfs_do_mount,
 	.kill_sb	= kill_litter_super,
 };
 
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index a4ed8380e98a..37a8ca7c1222 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -135,17 +135,17 @@ static int debug_fill_super(struct super_block *sb, void *data, int silent)
 	return simple_fill_super(sb, DEBUGFS_MAGIC, debug_files);
 }
 
-static int debug_get_sb(struct file_system_type *fs_type,
+static struct dentry *debug_mount(struct file_system_type *fs_type,
 			int flags, const char *dev_name,
-			void *data, struct vfsmount *mnt)
+			void *data)
 {
-	return get_sb_single(fs_type, flags, data, debug_fill_super, mnt);
+	return mount_single(fs_type, flags, data, debug_fill_super);
 }
 
 static struct file_system_type debug_fs_type = {
 	.owner =	THIS_MODULE,
 	.name =		"debugfs",
-	.get_sb =	debug_get_sb,
+	.mount =	debug_mount,
 	.kill_sb =	kill_litter_super,
 };
 
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 8b3ffd5b5235..1bb547c9cad6 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -331,7 +331,7 @@ static int compare_init_pts_sb(struct super_block *s, void *p)
 }
 
 /*
- * devpts_get_sb()
+ * devpts_mount()
  *
  *     If the '-o newinstance' mount option was specified, mount a new
  *     (private) instance of devpts.  PTYs created in this instance are
@@ -345,20 +345,20 @@ static int compare_init_pts_sb(struct super_block *s, void *p)
  *     semantics in devpts while preserving backward compatibility of the
  *     current 'single-namespace' semantics. i.e all mounts of devpts
  *     without the 'newinstance' mount option should bind to the initial
- *     kernel mount, like get_sb_single().
+ *     kernel mount, like mount_single().
  *
  *     Mounts with 'newinstance' option create a new, private namespace.
  *
  *     NOTE:
  *
- *     For single-mount semantics, devpts cannot use get_sb_single(),
- *     because get_sb_single()/sget() find and use the super-block from
+ *     For single-mount semantics, devpts cannot use mount_single(),
+ *     because mount_single()/sget() find and use the super-block from
  *     the most recent mount of devpts. But that recent mount may be a
- *     'newinstance' mount and get_sb_single() would pick the newinstance
+ *     'newinstance' mount and mount_single() would pick the newinstance
  *     super-block instead of the initial super-block.
  */
-static int devpts_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *devpts_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
 {
 	int error;
 	struct pts_mount_opts opts;
@@ -366,7 +366,7 @@ static int devpts_get_sb(struct file_system_type *fs_type,
 
 	error = parse_mount_options(data, PARSE_MOUNT, &opts);
 	if (error)
-		return error;
+		return ERR_PTR(error);
 
 	if (opts.newinstance)
 		s = sget(fs_type, NULL, set_anon_super, NULL);
@@ -374,7 +374,7 @@ static int devpts_get_sb(struct file_system_type *fs_type,
 		s = sget(fs_type, compare_init_pts_sb, set_anon_super, NULL);
 
 	if (IS_ERR(s))
-		return PTR_ERR(s);
+		return ERR_CAST(s);
 
 	if (!s->s_root) {
 		s->s_flags = flags;
@@ -390,13 +390,11 @@ static int devpts_get_sb(struct file_system_type *fs_type,
 	if (error)
 		goto out_undo_sget;
 
-	simple_set_mnt(mnt, s);
-
-	return 0;
+	return dget(s->s_root);
 
 out_undo_sget:
 	deactivate_locked_super(s);
-	return error;
+	return ERR_PTR(error);
 }
 
 #else
@@ -404,10 +402,10 @@ out_undo_sget:
  * This supports only the legacy single-instance semantics (no
  * multiple-instance semantics)
  */
-static int devpts_get_sb(struct file_system_type *fs_type, int flags,
-		const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *devpts_mount(struct file_system_type *fs_type, int flags,
+		const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, devpts_fill_super, mnt);
+	return mount_single(fs_type, flags, data, devpts_fill_super);
 }
 #endif
 
@@ -421,7 +419,7 @@ static void devpts_kill_sb(struct super_block *sb)
 
 static struct file_system_type devpts_fs_type = {
 	.name		= "devpts",
-	.get_sb		= devpts_get_sb,
+	.mount		= devpts_mount,
 	.kill_sb	= devpts_kill_sb,
 };
 
diff --git a/fs/fuse/control.c b/fs/fuse/control.c
index 4eba07661e5c..85542a7daf40 100644
--- a/fs/fuse/control.c
+++ b/fs/fuse/control.c
@@ -322,12 +322,10 @@ static int fuse_ctl_fill_super(struct super_block *sb, void *data, int silent)
 	return 0;
 }
 
-static int fuse_ctl_get_sb(struct file_system_type *fs_type, int flags,
-			const char *dev_name, void *raw_data,
-			struct vfsmount *mnt)
+static struct dentry *fuse_ctl_mount(struct file_system_type *fs_type,
+			int flags, const char *dev_name, void *raw_data)
 {
-	return get_sb_single(fs_type, flags, raw_data,
-				fuse_ctl_fill_super, mnt);
+	return mount_single(fs_type, flags, raw_data, fuse_ctl_fill_super);
 }
 
 static void fuse_ctl_kill_sb(struct super_block *sb)
@@ -346,7 +344,7 @@ static void fuse_ctl_kill_sb(struct super_block *sb)
 static struct file_system_type fuse_ctl_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "fusectl",
-	.get_sb		= fuse_ctl_get_sb,
+	.mount		= fuse_ctl_mount,
 	.kill_sb	= fuse_ctl_kill_sb,
 };
 
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index d6dc3f61f8ba..4514ebbee4d6 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1405,16 +1405,16 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
 	return simple_fill_super(sb, 0x6e667364, nfsd_files);
 }
 
-static int nfsd_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *nfsd_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, nfsd_fill_super, mnt);
+	return mount_single(fs_type, flags, data, nfsd_fill_super);
 }
 
 static struct file_system_type nfsd_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "nfsd",
-	.get_sb		= nfsd_get_sb,
+	.mount		= nfsd_mount,
 	.kill_sb	= kill_litter_super,
 };
 
diff --git a/fs/openpromfs/inode.c b/fs/openpromfs/inode.c
index ffcd04f0012c..ddb1f41376e5 100644
--- a/fs/openpromfs/inode.c
+++ b/fs/openpromfs/inode.c
@@ -415,16 +415,16 @@ out_no_root:
 	return ret;
 }
 
-static int openprom_get_sb(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *openprom_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, openprom_fill_super, mnt);
+	return mount_single(fs_type, flags, data, openprom_fill_super)
 }
 
 static struct file_system_type openprom_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "openpromfs",
-	.get_sb		= openprom_get_sb,
+	.mount		= openprom_mount,
 	.kill_sb	= kill_anon_super,
 };
 
diff --git a/fs/super.c b/fs/super.c
index 40989e9a2606..6f021a171ac6 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -900,29 +900,42 @@ static int compare_single(struct super_block *s, void *p)
 	return 1;
 }
 
-int get_sb_single(struct file_system_type *fs_type,
+struct dentry *mount_single(struct file_system_type *fs_type,
 	int flags, void *data,
-	int (*fill_super)(struct super_block *, void *, int),
-	struct vfsmount *mnt)
+	int (*fill_super)(struct super_block *, void *, int))
 {
 	struct super_block *s;
 	int error;
 
 	s = sget(fs_type, compare_single, set_anon_super, NULL);
 	if (IS_ERR(s))
-		return PTR_ERR(s);
+		return ERR_CAST(s);
 	if (!s->s_root) {
 		s->s_flags = flags;
 		error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
 		if (error) {
 			deactivate_locked_super(s);
-			return error;
+			return ERR_PTR(error);
 		}
 		s->s_flags |= MS_ACTIVE;
 	} else {
 		do_remount_sb(s, flags, data, 0);
 	}
-	simple_set_mnt(mnt, s);
+	return dget(s->s_root);
+}
+EXPORT_SYMBOL(mount_single);
+
+int get_sb_single(struct file_system_type *fs_type,
+	int flags, void *data,
+	int (*fill_super)(struct super_block *, void *, int),
+	struct vfsmount *mnt)
+{
+	struct dentry *root;
+	root = mount_single(fs_type, flags, data, fill_super);
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+	mnt->mnt_root = root;
+	mnt->mnt_sb = root->d_sb;
 	return 0;
 }
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2fab5a24ca51..0aa2f1202afa 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1799,6 +1799,9 @@ extern int get_sb_bdev(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *data,
 	int (*fill_super)(struct super_block *, void *, int),
 	struct vfsmount *mnt);
+extern struct dentry *mount_single(struct file_system_type *fs_type,
+	int flags, void *data,
+	int (*fill_super)(struct super_block *, void *, int));
 extern int get_sb_single(struct file_system_type *fs_type,
 	int flags, void *data,
 	int (*fill_super)(struct super_block *, void *, int),
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 7df92d237cb8..10a17a37ec4e 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -28,7 +28,7 @@
 #include <linux/sunrpc/rpc_pipe_fs.h>
 #include <linux/sunrpc/cache.h>
 
-static struct vfsmount *rpc_mount __read_mostly;
+static struct vfsmount *rpc_mnt __read_mostly;
 static int rpc_mount_count;
 
 static struct file_system_type rpc_pipe_fs_type;
@@ -417,16 +417,16 @@ struct vfsmount *rpc_get_mount(void)
 {
 	int err;
 
-	err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
+	err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mnt, &rpc_mount_count);
 	if (err != 0)
 		return ERR_PTR(err);
-	return rpc_mount;
+	return rpc_mnt;
 }
 EXPORT_SYMBOL_GPL(rpc_get_mount);
 
 void rpc_put_mount(void)
 {
-	simple_release_fs(&rpc_mount, &rpc_mount_count);
+	simple_release_fs(&rpc_mnt, &rpc_mount_count);
 }
 EXPORT_SYMBOL_GPL(rpc_put_mount);
 
@@ -1018,17 +1018,17 @@ rpc_fill_super(struct super_block *sb, void *data, int silent)
 	return 0;
 }
 
-static int
-rpc_get_sb(struct file_system_type *fs_type,
-		int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+static struct dentry *
+rpc_mount(struct file_system_type *fs_type,
+		int flags, const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
+	return mount_single(fs_type, flags, data, rpc_fill_super);
 }
 
 static struct file_system_type rpc_pipe_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "rpc_pipefs",
-	.get_sb		= rpc_get_sb,
+	.mount		= rpc_mount,
 	.kill_sb	= kill_litter_super,
 };
 
diff --git a/security/inode.c b/security/inode.c
index cb8f47c66a58..c4df2fbebe6b 100644
--- a/security/inode.c
+++ b/security/inode.c
@@ -131,17 +131,17 @@ static int fill_super(struct super_block *sb, void *data, int silent)
 	return simple_fill_super(sb, SECURITYFS_MAGIC, files);
 }
 
-static int get_sb(struct file_system_type *fs_type,
+static struct dentry *get_sb(struct file_system_type *fs_type,
 		  int flags, const char *dev_name,
-		  void *data, struct vfsmount *mnt)
+		  void *data)
 {
-	return get_sb_single(fs_type, flags, data, fill_super, mnt);
+	return mount_single(fs_type, flags, data, fill_super);
 }
 
 static struct file_system_type fs_type = {
 	.owner =	THIS_MODULE,
 	.name =		"securityfs",
-	.get_sb =	get_sb,
+	.mount =	get_sb,
 	.kill_sb =	kill_litter_super,
 };
 
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 55a755c1a1bd..073fd5b0a53a 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1909,16 +1909,15 @@ err:
 	goto out;
 }
 
-static int sel_get_sb(struct file_system_type *fs_type,
-		      int flags, const char *dev_name, void *data,
-		      struct vfsmount *mnt)
+static struct dentry *sel_mount(struct file_system_type *fs_type,
+		      int flags, const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, sel_fill_super, mnt);
+	return mount_single(fs_type, flags, data, sel_fill_super);
 }
 
 static struct file_system_type sel_fs_type = {
 	.name		= "selinuxfs",
-	.get_sb		= sel_get_sb,
+	.mount		= sel_mount,
 	.kill_sb	= kill_litter_super,
 };
 
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 7512502d0162..dc1fd6239f24 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -1310,27 +1310,25 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
 }
 
 /**
- * smk_get_sb - get the smackfs superblock
+ * smk_mount - get the smackfs superblock
  * @fs_type: passed along without comment
  * @flags: passed along without comment
  * @dev_name: passed along without comment
  * @data: passed along without comment
- * @mnt: passed along without comment
  *
  * Just passes everything along.
  *
  * Returns what the lower level code does.
  */
-static int smk_get_sb(struct file_system_type *fs_type,
-		      int flags, const char *dev_name, void *data,
-		      struct vfsmount *mnt)
+static struct dentry *smk_mount(struct file_system_type *fs_type,
+		      int flags, const char *dev_name, void *data)
 {
-	return get_sb_single(fs_type, flags, data, smk_fill_super, mnt);
+	return mount_single(fs_type, flags, data, smk_fill_super);
 }
 
 static struct file_system_type smk_fs_type = {
 	.name		= "smackfs",
-	.get_sb		= smk_get_sb,
+	.mount		= smk_mount,
 	.kill_sb	= kill_litter_super,
 };
 
-- 
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