From 680baacbca69d18a6d7315374ad83d05ac9c0977 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 2 May 2015 13:32:22 -0400
Subject: new ->follow_link() and ->put_link() calling conventions

a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body.  Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks.  Stored pointer
is ignored in all cases except the last one.

Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().

b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is.  In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 include/linux/namei.h | 2 --
 1 file changed, 2 deletions(-)

(limited to 'include/linux/namei.h')

diff --git a/include/linux/namei.h b/include/linux/namei.h
index c8990779f0c3..a5d5bed2c0e1 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -71,8 +71,6 @@ extern struct dentry *lock_rename(struct dentry *, struct dentry *);
 extern void unlock_rename(struct dentry *, struct dentry *);
 
 extern void nd_jump_link(struct nameidata *nd, struct path *path);
-extern void nd_set_link(struct nameidata *nd, char *path);
-extern char *nd_get_link(struct nameidata *nd);
 
 static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
 {
-- 
cgit v1.2.3


From 894bc8c4662ba9daceafe943a5ba0dd407da5cd3 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 2 May 2015 07:16:16 -0400
Subject: namei: remove restrictions on nesting depth

The only restriction is that on the total amount of symlinks
crossed; how they are nested does not matter

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/namei.c            | 66 ++++++++++++++++++++++++++++++++++++++++-----------
 include/linux/namei.h |  2 ++
 2 files changed, 54 insertions(+), 14 deletions(-)

(limited to 'include/linux/namei.h')

diff --git a/fs/namei.c b/fs/namei.c
index e5715a567860..1ae34cd0d590 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -492,6 +492,7 @@ void path_put(const struct path *path)
 }
 EXPORT_SYMBOL(path_put);
 
+#define EMBEDDED_LEVELS 2
 struct nameidata {
 	struct path	path;
 	union {
@@ -509,9 +510,42 @@ struct nameidata {
 		struct path link;
 		void *cookie;
 		const char *name;
-	} stack[MAX_NESTED_LINKS + 1];
+	} *stack, internal[EMBEDDED_LEVELS];
 };
 
+static void set_nameidata(struct nameidata *nd)
+{
+	nd->stack = nd->internal;
+}
+
+static void restore_nameidata(struct nameidata *nd)
+{
+	if (nd->stack != nd->internal) {
+		kfree(nd->stack);
+		nd->stack = nd->internal;
+	}
+}
+
+static int __nd_alloc_stack(struct nameidata *nd)
+{
+	struct saved *p = kmalloc((MAXSYMLINKS + 1) * sizeof(struct saved),
+				  GFP_KERNEL);
+	if (unlikely(!p))
+		return -ENOMEM;
+	memcpy(p, nd->internal, sizeof(nd->internal));
+	nd->stack = p;
+	return 0;
+}
+
+static inline int nd_alloc_stack(struct nameidata *nd)
+{
+	if (likely(nd->depth != EMBEDDED_LEVELS - 1))
+		return 0;
+	if (likely(nd->stack != nd->internal))
+		return 0;
+	return __nd_alloc_stack(nd);
+}
+
 /*
  * Path walking has 2 modes, rcu-walk and ref-walk (see
  * Documentation/filesystems/path-lookup.txt).  In situations when we can't
@@ -857,7 +891,7 @@ const char *get_link(struct nameidata *nd)
 	if (nd->link.mnt == nd->path.mnt)
 		mntget(nd->link.mnt);
 
-	if (unlikely(current->total_link_count >= 40)) {
+	if (unlikely(current->total_link_count >= MAXSYMLINKS)) {
 		path_put(&nd->path);
 		path_put(&nd->link);
 		return ERR_PTR(-ELOOP);
@@ -1789,22 +1823,18 @@ Walked:
 		if (err) {
 			const char *s;
 
-			if (unlikely(current->link_count >= MAX_NESTED_LINKS)) {
-				path_put_conditional(&nd->link, nd);
-				path_put(&nd->path);
-				err = -ELOOP;
-				goto Err;
+			err = nd_alloc_stack(nd);
+			if (unlikely(err)) {
+				path_to_nameidata(&nd->link, nd);
+				break;
 			}
-			BUG_ON(nd->depth >= MAX_NESTED_LINKS);
 
 			nd->depth++;
-			current->link_count++;
 
 			s = get_link(nd);
 
 			if (unlikely(IS_ERR(s))) {
 				err = PTR_ERR(s);
-				current->link_count--;
 				nd->depth--;
 				goto Err;
 			}
@@ -1812,7 +1842,6 @@ Walked:
 			if (unlikely(!s)) {
 				/* jumped */
 				put_link(nd);
-				current->link_count--;
 				nd->depth--;
 			} else {
 				if (*s == '/') {
@@ -1842,7 +1871,6 @@ Walked:
 Err:
 	while (unlikely(nd->depth)) {
 		put_link(nd);
-		current->link_count--;
 		nd->depth--;
 	}
 	return err;
@@ -1851,7 +1879,6 @@ OK:
 		name = nd->stack[nd->depth].name;
 		err = walk_component(nd, LOOKUP_FOLLOW);
 		put_link(nd);
-		current->link_count--;
 		nd->depth--;
 		goto Walked;
 	}
@@ -2055,7 +2082,11 @@ static int path_lookupat(int dfd, const struct filename *name,
 static int filename_lookup(int dfd, struct filename *name,
 				unsigned int flags, struct nameidata *nd)
 {
-	int retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd);
+	int retval;
+
+	set_nameidata(nd);
+	retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd);
+
 	if (unlikely(retval == -ECHILD))
 		retval = path_lookupat(dfd, name, flags, nd);
 	if (unlikely(retval == -ESTALE))
@@ -2063,6 +2094,7 @@ static int filename_lookup(int dfd, struct filename *name,
 
 	if (likely(!retval))
 		audit_inode(name, nd->path.dentry, flags & LOOKUP_PARENT);
+	restore_nameidata(nd);
 	return retval;
 }
 
@@ -2393,6 +2425,7 @@ filename_mountpoint(int dfd, struct filename *name, struct path *path,
 	int error;
 	if (IS_ERR(name))
 		return PTR_ERR(name);
+	set_nameidata(&nd);
 	error = path_mountpoint(dfd, name, path, &nd, flags | LOOKUP_RCU);
 	if (unlikely(error == -ECHILD))
 		error = path_mountpoint(dfd, name, path, &nd, flags);
@@ -2400,6 +2433,7 @@ filename_mountpoint(int dfd, struct filename *name, struct path *path,
 		error = path_mountpoint(dfd, name, path, &nd, flags | LOOKUP_REVAL);
 	if (likely(!error))
 		audit_inode(name, path->dentry, 0);
+	restore_nameidata(&nd);
 	putname(name);
 	return error;
 }
@@ -3288,11 +3322,13 @@ struct file *do_filp_open(int dfd, struct filename *pathname,
 	int flags = op->lookup_flags;
 	struct file *filp;
 
+	set_nameidata(&nd);
 	filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_RCU);
 	if (unlikely(filp == ERR_PTR(-ECHILD)))
 		filp = path_openat(dfd, pathname, &nd, op, flags);
 	if (unlikely(filp == ERR_PTR(-ESTALE)))
 		filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_REVAL);
+	restore_nameidata(&nd);
 	return filp;
 }
 
@@ -3306,6 +3342,7 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
 
 	nd.root.mnt = mnt;
 	nd.root.dentry = dentry;
+	set_nameidata(&nd);
 
 	if (d_is_symlink(dentry) && op->intent & LOOKUP_OPEN)
 		return ERR_PTR(-ELOOP);
@@ -3319,6 +3356,7 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
 		file = path_openat(-1, filename, &nd, op, flags);
 	if (unlikely(file == ERR_PTR(-ESTALE)))
 		file = path_openat(-1, filename, &nd, op, flags | LOOKUP_REVAL);
+	restore_nameidata(&nd);
 	putname(filename);
 	return file;
 }
diff --git a/include/linux/namei.h b/include/linux/namei.h
index a5d5bed2c0e1..3a6cc9651712 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -11,6 +11,8 @@ struct nameidata;
 
 enum { MAX_NESTED_LINKS = 8 };
 
+#define MAXSYMLINKS 40
+
 /*
  * Type of the last component on LOOKUP_PARENT
  */
-- 
cgit v1.2.3


From 6e77137b363b8d866ac29c5a0c95e953614fb2d8 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 2 May 2015 13:37:52 -0400
Subject: don't pass nameidata to ->follow_link()

its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidata

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 Documentation/filesystems/Locking             |  2 +-
 Documentation/filesystems/vfs.txt             |  2 +-
 drivers/staging/lustre/lustre/llite/symlink.c |  2 +-
 fs/9p/vfs_inode.c                             |  2 +-
 fs/9p/vfs_inode_dotl.c                        |  2 +-
 fs/autofs4/symlink.c                          |  2 +-
 fs/befs/linuxvfs.c                            |  4 ++--
 fs/cifs/cifsfs.h                              |  2 +-
 fs/cifs/link.c                                |  2 +-
 fs/configfs/symlink.c                         |  2 +-
 fs/ecryptfs/inode.c                           |  2 +-
 fs/ext4/symlink.c                             |  2 +-
 fs/f2fs/namei.c                               |  4 ++--
 fs/fuse/dir.c                                 |  2 +-
 fs/gfs2/inode.c                               |  2 +-
 fs/hostfs/hostfs_kern.c                       |  2 +-
 fs/hppfs/hppfs.c                              |  4 ++--
 fs/kernfs/symlink.c                           |  2 +-
 fs/libfs.c                                    |  2 +-
 fs/namei.c                                    | 11 ++++++-----
 fs/nfs/symlink.c                              |  2 +-
 fs/overlayfs/inode.c                          |  4 ++--
 fs/proc/base.c                                |  4 ++--
 fs/proc/inode.c                               |  2 +-
 fs/proc/namespaces.c                          |  4 ++--
 fs/proc/self.c                                |  2 +-
 fs/proc/thread_self.c                         |  2 +-
 fs/xfs/xfs_iops.c                             |  3 +--
 include/linux/fs.h                            |  6 +++---
 include/linux/namei.h                         |  2 +-
 mm/shmem.c                                    |  2 +-
 31 files changed, 44 insertions(+), 44 deletions(-)

(limited to 'include/linux/namei.h')

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 7fa6c4ac858c..5b5b4f54c033 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -50,7 +50,7 @@ prototypes:
 	int (*rename2) (struct inode *, struct dentry *,
 			struct inode *, struct dentry *, unsigned int);
 	int (*readlink) (struct dentry *, char __user *,int);
-	const char *(*follow_link) (struct dentry *, void **, struct nameidata *);
+	const char *(*follow_link) (struct dentry *, void **);
 	void (*put_link) (struct dentry *, void *);
 	void (*truncate) (struct inode *);
 	int (*permission) (struct inode *, int, unsigned int);
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 1c6b03ac2e5a..0dec8c880be6 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -350,7 +350,7 @@ struct inode_operations {
 	int (*rename2) (struct inode *, struct dentry *,
 			struct inode *, struct dentry *, unsigned int);
 	int (*readlink) (struct dentry *, char __user *,int);
-	const char *(*follow_link) (struct dentry *, void **, struct nameidata *);
+	const char *(*follow_link) (struct dentry *, void **);
 	void (*put_link) (struct dentry *, void *);
 	int (*permission) (struct inode *, int);
 	int (*get_acl)(struct inode *, int);
diff --git a/drivers/staging/lustre/lustre/llite/symlink.c b/drivers/staging/lustre/lustre/llite/symlink.c
index da6d9d17c50d..f3be3bf0f66f 100644
--- a/drivers/staging/lustre/lustre/llite/symlink.c
+++ b/drivers/staging/lustre/lustre/llite/symlink.c
@@ -118,7 +118,7 @@ failed:
 	return rc;
 }
 
-static const char *ll_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *ll_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct inode *inode = d_inode(dentry);
 	struct ptlrpc_request *request = NULL;
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 7cc70a39a1d8..271f51af2f75 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1230,7 +1230,7 @@ ino_t v9fs_qid2ino(struct p9_qid *qid)
  *
  */
 
-static const char *v9fs_vfs_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *v9fs_vfs_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct v9fs_session_info *v9ses = v9fs_dentry2v9ses(dentry);
 	struct p9_fid *fid = v9fs_fid_lookup(dentry);
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index ae062ffa0f1f..16658ed677c9 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -910,7 +910,7 @@ error:
  */
 
 static const char *
-v9fs_vfs_follow_link_dotl(struct dentry *dentry, void **cookie, struct nameidata *nd)
+v9fs_vfs_follow_link_dotl(struct dentry *dentry, void **cookie)
 {
 	struct p9_fid *fid = v9fs_fid_lookup(dentry);
 	char *target;
diff --git a/fs/autofs4/symlink.c b/fs/autofs4/symlink.c
index 9c6a07739c9b..da0c33481bc0 100644
--- a/fs/autofs4/symlink.c
+++ b/fs/autofs4/symlink.c
@@ -12,7 +12,7 @@
 
 #include "autofs_i.h"
 
-static const char *autofs4_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *autofs4_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
 	struct autofs_info *ino = autofs4_dentry_ino(dentry);
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index 3a1aefb86a11..46aedacfa6a8 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -42,7 +42,7 @@ static struct inode *befs_iget(struct super_block *, unsigned long);
 static struct inode *befs_alloc_inode(struct super_block *sb);
 static void befs_destroy_inode(struct inode *inode);
 static void befs_destroy_inodecache(void);
-static const char *befs_follow_link(struct dentry *, void **, struct nameidata *nd);
+static const char *befs_follow_link(struct dentry *, void **);
 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
 			char **out, int *out_len);
 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
@@ -464,7 +464,7 @@ befs_destroy_inodecache(void)
  * flag is set.
  */
 static const char *
-befs_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+befs_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct super_block *sb = dentry->d_sb;
 	struct befs_inode_info *befs_ino = BEFS_I(d_inode(dentry));
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 61012da7e9d8..a782b22904e4 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -120,7 +120,7 @@ extern struct vfsmount *cifs_dfs_d_automount(struct path *path);
 #endif
 
 /* Functions related to symlinks */
-extern const char *cifs_follow_link(struct dentry *direntry, void **cookie, struct nameidata *nd);
+extern const char *cifs_follow_link(struct dentry *direntry, void **cookie);
 extern int cifs_readlink(struct dentry *direntry, char __user *buffer,
 			 int buflen);
 extern int cifs_symlink(struct inode *inode, struct dentry *direntry,
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 4a439c2c0c7f..546f86ab09aa 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -627,7 +627,7 @@ cifs_hl_exit:
 }
 
 const char *
-cifs_follow_link(struct dentry *direntry, void **cookie, struct nameidata *nd)
+cifs_follow_link(struct dentry *direntry, void **cookie)
 {
 	struct inode *inode = d_inode(direntry);
 	int rc = -ENOMEM;
diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c
index fac8e8517f33..0ace75649009 100644
--- a/fs/configfs/symlink.c
+++ b/fs/configfs/symlink.c
@@ -279,7 +279,7 @@ static int configfs_getlink(struct dentry *dentry, char * path)
 
 }
 
-static const char *configfs_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *configfs_follow_link(struct dentry *dentry, void **cookie)
 {
 	unsigned long page = get_zeroed_page(GFP_KERNEL);
 	int error;
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index cdb9d6c4532d..73d20ae92478 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -675,7 +675,7 @@ out:
 	return rc ? ERR_PTR(rc) : buf;
 }
 
-static const char *ecryptfs_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *ecryptfs_follow_link(struct dentry *dentry, void **cookie)
 {
 	size_t len;
 	char *buf = ecryptfs_readlink_lower(dentry, &len);
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index afec475aaf5c..ba5bd18a9825 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -23,7 +23,7 @@
 #include "xattr.h"
 
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-static const char *ext4_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *ext4_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct page *cpage = NULL;
 	char *caddr, *paddr = NULL;
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index d2947937515e..cd05a7c91533 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -296,9 +296,9 @@ fail:
 	return err;
 }
 
-static const char *f2fs_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *f2fs_follow_link(struct dentry *dentry, void **cookie)
 {
-	const char *link = page_follow_link_light(dentry, cookie, nd);
+	const char *link = page_follow_link_light(dentry, cookie);
 	if (!IS_ERR(link) && !*link) {
 		/* this is broken symlink case */
 		page_put_link(dentry, *cookie);
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index f9cb260375cf..d5cdef8b7f3a 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1365,7 +1365,7 @@ static int fuse_readdir(struct file *file, struct dir_context *ctx)
 	return err;
 }
 
-static const char *fuse_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *fuse_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct inode *inode = d_inode(dentry);
 	struct fuse_conn *fc = get_fuse_conn(inode);
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index f59390aebffb..3a1461de1551 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1548,7 +1548,7 @@ out:
  * Returns: 0 on success or error code
  */
 
-static const char *gfs2_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *gfs2_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct gfs2_inode *ip = GFS2_I(d_inode(dentry));
 	struct gfs2_holder i_gh;
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index f650ed661fab..7b6ed7a908f6 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -892,7 +892,7 @@ static const struct inode_operations hostfs_dir_iops = {
 	.setattr	= hostfs_setattr,
 };
 
-static const char *hostfs_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *hostfs_follow_link(struct dentry *dentry, void **cookie)
 {
 	char *link = __getname();
 	if (link) {
diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c
index b8f24d3b04ee..15a774eb5bbf 100644
--- a/fs/hppfs/hppfs.c
+++ b/fs/hppfs/hppfs.c
@@ -642,11 +642,11 @@ static int hppfs_readlink(struct dentry *dentry, char __user *buffer,
 						    buflen);
 }
 
-static const char *hppfs_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *hppfs_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct dentry *proc_dentry = HPPFS_I(d_inode(dentry))->proc_dentry;
 
-	return d_inode(proc_dentry)->i_op->follow_link(proc_dentry, cookie, nd);
+	return d_inode(proc_dentry)->i_op->follow_link(proc_dentry, cookie);
 }
 
 static void hppfs_put_link(struct dentry *dentry, void *cookie)
diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index 3c7e799974a2..366c5a17475e 100644
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -112,7 +112,7 @@ static int kernfs_getlink(struct dentry *dentry, char *path)
 	return error;
 }
 
-static const char *kernfs_iop_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *kernfs_iop_follow_link(struct dentry *dentry, void **cookie)
 {
 	int error = -ENOMEM;
 	unsigned long page = get_zeroed_page(GFP_KERNEL);
diff --git a/fs/libfs.c b/fs/libfs.c
index 0c83fde20dbd..c5f3373e326b 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -1091,7 +1091,7 @@ simple_nosetlease(struct file *filp, long arg, struct file_lock **flp,
 }
 EXPORT_SYMBOL(simple_nosetlease);
 
-const char *simple_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+const char *simple_follow_link(struct dentry *dentry, void **cookie)
 {
 	return d_inode(dentry)->i_link;
 }
diff --git a/fs/namei.c b/fs/namei.c
index b57400ca6a0f..f311f0369e3c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -753,8 +753,9 @@ static inline void path_to_nameidata(const struct path *path,
  * Helper to directly jump to a known parsed path from ->follow_link,
  * caller must have taken a reference to path beforehand.
  */
-void nd_jump_link(struct nameidata *nd, struct path *path)
+void nd_jump_link(struct path *path)
 {
+	struct nameidata *nd = current->nameidata;
 	path_put(&nd->path);
 
 	nd->path = *path;
@@ -916,7 +917,7 @@ const char *get_link(struct nameidata *nd)
 	nd->last_type = LAST_BIND;
 	res = inode->i_link;
 	if (!res) {
-		res = inode->i_op->follow_link(dentry, &last->cookie, nd);
+		res = inode->i_op->follow_link(dentry, &last->cookie);
 		if (IS_ERR(res)) {
 out:
 			path_put(&last->link);
@@ -4485,12 +4486,12 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 	int res;
 
 	if (!link) {
-		link = dentry->d_inode->i_op->follow_link(dentry, &cookie, NULL);
+		link = dentry->d_inode->i_op->follow_link(dentry, &cookie);
 		if (IS_ERR(link))
 			return PTR_ERR(link);
 	}
 	res = readlink_copy(buffer, buflen, link);
-	if (cookie && dentry->d_inode->i_op->put_link)
+	if (dentry->d_inode->i_op->put_link)
 		dentry->d_inode->i_op->put_link(dentry, cookie);
 	return res;
 }
@@ -4523,7 +4524,7 @@ int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 }
 EXPORT_SYMBOL(page_readlink);
 
-const char *page_follow_link_light(struct dentry *dentry, void **cookie, struct nameidata *nd)
+const char *page_follow_link_light(struct dentry *dentry, void **cookie)
 {
 	struct page *page = NULL;
 	char *res = page_getlink(dentry, &page);
diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
index c992b200ae7e..b6de433da5db 100644
--- a/fs/nfs/symlink.c
+++ b/fs/nfs/symlink.c
@@ -42,7 +42,7 @@ error:
 	return -EIO;
 }
 
-static const char *nfs_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *nfs_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct inode *inode = d_inode(dentry);
 	struct page *page;
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 235ad42afb57..9986833c9fcc 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -140,7 +140,7 @@ struct ovl_link_data {
 	void *cookie;
 };
 
-static const char *ovl_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *ovl_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct dentry *realdentry;
 	struct inode *realinode;
@@ -160,7 +160,7 @@ static const char *ovl_follow_link(struct dentry *dentry, void **cookie, struct
 		data->realdentry = realdentry;
 	}
 
-	ret = realinode->i_op->follow_link(realdentry, cookie, nd);
+	ret = realinode->i_op->follow_link(realdentry, cookie);
 	if (IS_ERR_OR_NULL(ret)) {
 		kfree(data);
 		return ret;
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 52652f86b187..286a422f440e 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1380,7 +1380,7 @@ static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
 		return -ENOENT;
 }
 
-static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct inode *inode = d_inode(dentry);
 	struct path path;
@@ -1394,7 +1394,7 @@ static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie, st
 	if (error)
 		goto out;
 
-	nd_jump_link(nd, &path);
+	nd_jump_link(&path);
 	return NULL;
 out:
 	return ERR_PTR(error);
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index acd51d75387d..eb35874fe09c 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -393,7 +393,7 @@ static const struct file_operations proc_reg_file_ops_no_compat = {
 };
 #endif
 
-static const char *proc_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *proc_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct proc_dir_entry *pde = PDE(d_inode(dentry));
 	if (unlikely(!use_pde(pde)))
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 10d24dd096e8..f6e8354b8cea 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -30,7 +30,7 @@ static const struct proc_ns_operations *ns_entries[] = {
 	&mntns_operations,
 };
 
-static const char *proc_ns_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *proc_ns_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct inode *inode = d_inode(dentry);
 	const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
@@ -45,7 +45,7 @@ static const char *proc_ns_follow_link(struct dentry *dentry, void **cookie, str
 	if (ptrace_may_access(task, PTRACE_MODE_READ)) {
 		error = ns_get_path(&ns_path, task, ns_ops);
 		if (!error)
-			nd_jump_link(nd, &ns_path);
+			nd_jump_link(&ns_path);
 	}
 	put_task_struct(task);
 	return error;
diff --git a/fs/proc/self.c b/fs/proc/self.c
index ad333946b53a..113b8d061fc0 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -18,7 +18,7 @@ static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
 	return readlink_copy(buffer, buflen, tmp);
 }
 
-static const char *proc_self_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *proc_self_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
 	pid_t tgid = task_tgid_nr_ns(current, ns);
diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index 85c96e0d7aaa..947b0f4fd0a1 100644
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -19,7 +19,7 @@ static int proc_thread_self_readlink(struct dentry *dentry, char __user *buffer,
 	return readlink_copy(buffer, buflen, tmp);
 }
 
-static const char *proc_thread_self_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *proc_thread_self_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
 	pid_t tgid = task_tgid_nr_ns(current, ns);
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 26c4dcb1ef56..7f51f39f8acc 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -416,8 +416,7 @@ xfs_vn_rename(
 STATIC const char *
 xfs_vn_follow_link(
 	struct dentry		*dentry,
-	void			**cookie,
-	struct nameidata	*nd)
+	void			**cookie)
 {
 	char			*link;
 	int			error = -ENOMEM;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9ab934113a28..ed7c9f298759 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1608,7 +1608,7 @@ struct file_operations {
 
 struct inode_operations {
 	struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
-	const char * (*follow_link) (struct dentry *, void **, struct nameidata *);
+	const char * (*follow_link) (struct dentry *, void **);
 	int (*permission) (struct inode *, int);
 	struct posix_acl * (*get_acl)(struct inode *, int);
 
@@ -2705,7 +2705,7 @@ extern const struct file_operations generic_ro_fops;
 
 extern int readlink_copy(char __user *, int, const char *);
 extern int page_readlink(struct dentry *, char __user *, int);
-extern const char *page_follow_link_light(struct dentry *, void **, struct nameidata *);
+extern const char *page_follow_link_light(struct dentry *, void **);
 extern void page_put_link(struct dentry *, void *);
 extern int __page_symlink(struct inode *inode, const char *symname, int len,
 		int nofs);
@@ -2722,7 +2722,7 @@ void __inode_sub_bytes(struct inode *inode, loff_t bytes);
 void inode_sub_bytes(struct inode *inode, loff_t bytes);
 loff_t inode_get_bytes(struct inode *inode);
 void inode_set_bytes(struct inode *inode, loff_t bytes);
-const char *simple_follow_link(struct dentry *, void **, struct nameidata *);
+const char *simple_follow_link(struct dentry *, void **);
 extern const struct inode_operations simple_symlink_inode_operations;
 
 extern int iterate_dir(struct file *, struct dir_context *);
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 3a6cc9651712..d756304aa09b 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -72,7 +72,7 @@ extern int follow_up(struct path *);
 extern struct dentry *lock_rename(struct dentry *, struct dentry *);
 extern void unlock_rename(struct dentry *, struct dentry *);
 
-extern void nd_jump_link(struct nameidata *nd, struct path *path);
+extern void nd_jump_link(struct path *path);
 
 static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
 {
diff --git a/mm/shmem.c b/mm/shmem.c
index d1693dcb4285..e02682267046 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2475,7 +2475,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
 	return 0;
 }
 
-static const char *shmem_follow_link(struct dentry *dentry, void **cookie, struct nameidata *nd)
+static const char *shmem_follow_link(struct dentry *dentry, void **cookie)
 {
 	struct page *page = NULL;
 	int error = shmem_getpage(d_inode(dentry), 0, &page, SGP_READ, NULL);
-- 
cgit v1.2.3


From 89076bc31950eee576ecc06460c23466e2d50939 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Tue, 12 May 2015 08:29:38 -0400
Subject: get rid of assorted nameidata-related debris

pointless forward declarations, stale comments

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/9p/vfs_inode.c      | 3 +--
 fs/9p/vfs_inode_dotl.c | 3 +--
 fs/ecryptfs/inode.c    | 3 +--
 fs/ntfs/namei.c        | 2 +-
 include/linux/fs.h     | 1 -
 include/linux/namei.h  | 1 -
 include/linux/sched.h  | 1 +
 7 files changed, 5 insertions(+), 9 deletions(-)

(limited to 'include/linux/namei.h')

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 271f51af2f75..510040b04c96 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1226,8 +1226,7 @@ ino_t v9fs_qid2ino(struct p9_qid *qid)
 /**
  * v9fs_vfs_follow_link - follow a symlink path
  * @dentry: dentry for symlink
- * @nd: nameidata
- *
+ * @cookie: place to pass the data to put_link()
  */
 
 static const char *v9fs_vfs_follow_link(struct dentry *dentry, void **cookie)
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 16658ed677c9..09e4433717b8 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -905,8 +905,7 @@ error:
 /**
  * v9fs_vfs_follow_link_dotl - follow a symlink path
  * @dentry: dentry for symlink
- * @nd: nameidata
- *
+ * @cookie: place to pass the data to put_link()
  */
 
 static const char *
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 73d20ae92478..3c4db1172d22 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -170,7 +170,6 @@ out_unlock:
  * @directory_inode: inode of the new file's dentry's parent in ecryptfs
  * @ecryptfs_dentry: New file's dentry in ecryptfs
  * @mode: The mode of the new file
- * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
  *
  * Creates the underlying file and the eCryptfs inode which will link to
  * it. It will also update the eCryptfs directory inode to mimic the
@@ -384,7 +383,7 @@ static int ecryptfs_lookup_interpose(struct dentry *dentry,
  * ecryptfs_lookup
  * @ecryptfs_dir_inode: The eCryptfs directory inode
  * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
- * @ecryptfs_nd: nameidata; may be NULL
+ * @flags: lookup flags
  *
  * Find a file on disk. If the file does not exist, then we'll add it to the
  * dentry cache and continue on to read it from the disk.
diff --git a/fs/ntfs/namei.c b/fs/ntfs/namei.c
index 0f35b80d17fe..443abecf01b7 100644
--- a/fs/ntfs/namei.c
+++ b/fs/ntfs/namei.c
@@ -35,7 +35,7 @@
  * ntfs_lookup - find the inode represented by a dentry in a directory inode
  * @dir_ino:	directory inode in which to look for the inode
  * @dent:	dentry representing the inode to look for
- * @nd:		lookup nameidata
+ * @flags:	lookup flags
  *
  * In short, ntfs_lookup() looks for the inode represented by the dentry @dent
  * in the directory inode @dir_ino and if found attaches the inode to the
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1426c435d455..b577e801b4af 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -38,7 +38,6 @@ struct backing_dev_info;
 struct export_operations;
 struct hd_geometry;
 struct iovec;
-struct nameidata;
 struct kiocb;
 struct kobject;
 struct pipe_inode_info;
diff --git a/include/linux/namei.h b/include/linux/namei.h
index d756304aa09b..1208e489f83e 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -7,7 +7,6 @@
 #include <linux/path.h>
 
 struct vfsmount;
-struct nameidata;
 
 enum { MAX_NESTED_LINKS = 8 };
 
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f6c9b69d66f2..a1158c954f0f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -132,6 +132,7 @@ struct fs_struct;
 struct perf_event_context;
 struct blk_plug;
 struct filename;
+struct nameidata;
 
 #define VMACACHE_BITS 2
 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
-- 
cgit v1.2.3


From b853a16176cf3e02c57e215743015614152c2428 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 13 May 2015 09:12:02 -0400
Subject: turn user_{path_at,path,lpath,path_dir}() into static inlines

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/namei.c            |  8 +-------
 include/linux/namei.h | 34 ++++++++++++++++++++++++----------
 2 files changed, 25 insertions(+), 17 deletions(-)

(limited to 'include/linux/namei.h')

diff --git a/fs/namei.c b/fs/namei.c
index 1a117c0d13c5..2dad0eaf91d3 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2299,13 +2299,7 @@ int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
 	return filename_lookup(dfd, getname_flags(name, flags, empty),
 			       flags, path, NULL);
 }
-
-int user_path_at(int dfd, const char __user *name, unsigned flags,
-		 struct path *path)
-{
-	return user_path_at_empty(dfd, name, flags, path, NULL);
-}
-EXPORT_SYMBOL(user_path_at);
+EXPORT_SYMBOL(user_path_at_empty);
 
 /*
  * NB: most callers don't do anything directly with the reference to the
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 1208e489f83e..d8c6334cd150 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -1,12 +1,10 @@
 #ifndef _LINUX_NAMEI_H
 #define _LINUX_NAMEI_H
 
-#include <linux/dcache.h>
-#include <linux/errno.h>
-#include <linux/linkage.h>
+#include <linux/kernel.h>
 #include <linux/path.h>
-
-struct vfsmount;
+#include <linux/fcntl.h>
+#include <linux/errno.h>
 
 enum { MAX_NESTED_LINKS = 8 };
 
@@ -46,13 +44,29 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
 #define LOOKUP_ROOT		0x2000
 #define LOOKUP_EMPTY		0x4000
 
-extern int user_path_at(int, const char __user *, unsigned, struct path *);
 extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
 
-#define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path)
-#define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path)
-#define user_path_dir(name, path) \
-	user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path)
+static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
+		 struct path *path)
+{
+	return user_path_at_empty(dfd, name, flags, path, NULL);
+}
+
+static inline int user_path(const char __user *name, struct path *path)
+{
+	return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
+}
+
+static inline int user_lpath(const char __user *name, struct path *path)
+{
+	return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
+}
+
+static inline int user_path_dir(const char __user *name, struct path *path)
+{
+	return user_path_at_empty(AT_FDCWD, name,
+				  LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path, NULL);
+}
 
 extern int kern_path(const char *, unsigned, struct path *);
 
-- 
cgit v1.2.3