Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  isofs: Fix lseek() to position beyond 4 GB
  vfs: remove unused MNT_STRICTATIME
  vfs: show unreachable paths in getcwd and proc
  vfs: only add " (deleted)" where necessary
  vfs: add prepend_path() helper
  vfs: __d_path: dont prepend the name of the root dentry
  ia64: perfmon: add d_dname method
  vfs: add helpers to get root and pwd
  cachefiles: use path_get instead of lone dget
  fs/sysv/super.c: add support for non-PDP11 v7 filesystems
  V7: Adjust sanity checks for some volumes
  Add v7 alias
  v9fs: fixup for inode_setattr being removed

Manual merge to take Al's version of the fs/sysv/super.c file: it merged
cleanly, but Al had removed an unnecessary header include, so his side
was better.

9 files changed, 180 insertions, 115 deletions

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index d97c34a..c7c23ea 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1263,10 +1263,19 @@ static int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
 		return PTR_ERR(fid);
 
 	retval = p9_client_setattr(fid, &p9attr);
-	if (retval >= 0)
-		retval = inode_setattr(dentry->d_inode, iattr);
+	if (retval < 0)
+		return retval;
 
-	return retval;
+	if ((iattr->ia_valid & ATTR_SIZE) &&
+	    iattr->ia_size != i_size_read(dentry->d_inode)) {
+		retval = vmtruncate(dentry->d_inode, iattr->ia_size);
+		if (retval)
+			return retval;
+	}
+
+	setattr_copy(dentry->d_inode, iattr);
+	mark_inode_dirty(dentry->d_inode);
+	return 0;
 }
 
 /**
diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 24eb0d3..727caed 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -552,8 +552,7 @@ static int cachefiles_daemon_tag(struct cachefiles_cache *cache, char *args)
  */
 static int cachefiles_daemon_cull(struct cachefiles_cache *cache, char *args)
 {
-	struct fs_struct *fs;
-	struct dentry *dir;
+	struct path path;
 	const struct cred *saved_cred;
 	int ret;
 
@@ -573,24 +572,21 @@ static int cachefiles_daemon_cull(struct cachefiles_cache *cache, char *args)
 	}
 
 	/* extract the directory dentry from the cwd */
-	fs = current->fs;
-	read_lock(&fs->lock);
-	dir = dget(fs->pwd.dentry);
-	read_unlock(&fs->lock);
+	get_fs_pwd(current->fs, &path);
 
-	if (!S_ISDIR(dir->d_inode->i_mode))
+	if (!S_ISDIR(path.dentry->d_inode->i_mode))
 		goto notdir;
 
 	cachefiles_begin_secure(cache, &saved_cred);
-	ret = cachefiles_cull(cache, dir, args);
+	ret = cachefiles_cull(cache, path.dentry, args);
 	cachefiles_end_secure(cache, saved_cred);
 
-	dput(dir);
+	path_put(&path);
 	_leave(" = %d", ret);
 	return ret;
 
 notdir:
-	dput(dir);
+	path_put(&path);
 	kerror("cull command requires dirfd to be a directory");
 	return -ENOTDIR;
 
@@ -628,8 +624,7 @@ inval:
  */
 static int cachefiles_daemon_inuse(struct cachefiles_cache *cache, char *args)
 {
-	struct fs_struct *fs;
-	struct dentry *dir;
+	struct path path;
 	const struct cred *saved_cred;
 	int ret;
 
@@ -649,24 +644,21 @@ static int cachefiles_daemon_inuse(struct cachefiles_cache *cache, char *args)
 	}
 
 	/* extract the directory dentry from the cwd */
-	fs = current->fs;
-	read_lock(&fs->lock);
-	dir = dget(fs->pwd.dentry);
-	read_unlock(&fs->lock);
+	get_fs_pwd(current->fs, &path);
 
-	if (!S_ISDIR(dir->d_inode->i_mode))
+	if (!S_ISDIR(path.dentry->d_inode->i_mode))
 		goto notdir;
 
 	cachefiles_begin_secure(cache, &saved_cred);
-	ret = cachefiles_check_in_use(cache, dir, args);
+	ret = cachefiles_check_in_use(cache, path.dentry, args);
 	cachefiles_end_secure(cache, saved_cred);
 
-	dput(dir);
+	path_put(&path);
 	//_leave(" = %d", ret);
 	return ret;
 
 notdir:
-	dput(dir);
+	path_put(&path);
 	kerror("inuse command requires dirfd to be a directory");
 	return -ENOTDIR;
 
diff --git a/fs/dcache.c b/fs/dcache.c
index 9f2c134..166d35d 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1905,48 +1905,30 @@ static int prepend_name(char **buffer, int *buflen, struct qstr *name)
 }
 
 /**
- * __d_path - return the path of a dentry
+ * Prepend path string to a buffer
+ *
  * @path: the dentry/vfsmount to report
  * @root: root vfsmnt/dentry (may be modified by this function)
- * @buffer: buffer to return value in
- * @buflen: buffer length
+ * @buffer: pointer to the end of the buffer
+ * @buflen: pointer to buffer length
  *
- * Convert a dentry into an ASCII path name. If the entry has been deleted
- * the string " (deleted)" is appended. Note that this is ambiguous.
- *
- * Returns a pointer into the buffer or an error code if the
- * path was too long.
- *
- * "buflen" should be positive. Caller holds the dcache_lock.
+ * Caller holds the dcache_lock.
  *
  * If path is not reachable from the supplied root, then the value of
  * root is changed (without modifying refcounts).
  */
-char *__d_path(const struct path *path, struct path *root,
-	       char *buffer, int buflen)
+static int prepend_path(const struct path *path, struct path *root,
+			char **buffer, int *buflen)
 {
 	struct dentry *dentry = path->dentry;
 	struct vfsmount *vfsmnt = path->mnt;
-	char *end = buffer + buflen;
-	char *retval;
+	bool slash = false;
+	int error = 0;
 
 	spin_lock(&vfsmount_lock);
-	prepend(&end, &buflen, "\0", 1);
-	if (d_unlinked(dentry) &&
-		(prepend(&end, &buflen, " (deleted)", 10) != 0))
-			goto Elong;
-
-	if (buflen < 1)
-		goto Elong;
-	/* Get '/' right */
-	retval = end-1;
-	*retval = '/';
-
-	for (;;) {
+	while (dentry != root->dentry || vfsmnt != root->mnt) {
 		struct dentry * parent;
 
-		if (dentry == root->dentry && vfsmnt == root->mnt)
-			break;
 		if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
 			/* Global root? */
 			if (vfsmnt->mnt_parent == vfsmnt) {
@@ -1958,28 +1940,88 @@ char *__d_path(const struct path *path, struct path *root,
 		}
 		parent = dentry->d_parent;
 		prefetch(parent);
-		if ((prepend_name(&end, &buflen, &dentry->d_name) != 0) ||
-		    (prepend(&end, &buflen, "/", 1) != 0))
-			goto Elong;
-		retval = end;
+		error = prepend_name(buffer, buflen, &dentry->d_name);
+		if (!error)
+			error = prepend(buffer, buflen, "/", 1);
+		if (error)
+			break;
+
+		slash = true;
 		dentry = parent;
 	}
 
 out:
+	if (!error && !slash)
+		error = prepend(buffer, buflen, "/", 1);
+
 	spin_unlock(&vfsmount_lock);
-	return retval;
+	return error;
 
 global_root:
-	retval += 1;	/* hit the slash */
-	if (prepend_name(&retval, &buflen, &dentry->d_name) != 0)
-		goto Elong;
+	/*
+	 * Filesystems needing to implement special "root names"
+	 * should do so with ->d_dname()
+	 */
+	if (IS_ROOT(dentry) &&
+	    (dentry->d_name.len != 1 || dentry->d_name.name[0] != '/')) {
+		WARN(1, "Root dentry has weird name <%.*s>\n",
+		     (int) dentry->d_name.len, dentry->d_name.name);
+	}
 	root->mnt = vfsmnt;
 	root->dentry = dentry;
 	goto out;
+}
 
-Elong:
-	retval = ERR_PTR(-ENAMETOOLONG);
-	goto out;
+/**
+ * __d_path - return the path of a dentry
+ * @path: the dentry/vfsmount to report
+ * @root: root vfsmnt/dentry (may be modified by this function)
+ * @buffer: buffer to return value in
+ * @buflen: buffer length
+ *
+ * Convert a dentry into an ASCII path name.
+ *
+ * Returns a pointer into the buffer or an error code if the
+ * path was too long.
+ *
+ * "buflen" should be positive. Caller holds the dcache_lock.
+ *
+ * If path is not reachable from the supplied root, then the value of
+ * root is changed (without modifying refcounts).
+ */
+char *__d_path(const struct path *path, struct path *root,
+	       char *buf, int buflen)
+{
+	char *res = buf + buflen;
+	int error;
+
+	prepend(&res, &buflen, "\0", 1);
+	error = prepend_path(path, root, &res, &buflen);
+	if (error)
+		return ERR_PTR(error);
+
+	return res;
+}
+
+/*
+ * same as __d_path but appends "(deleted)" for unlinked files.
+ */
+static int path_with_deleted(const struct path *path, struct path *root,
+				 char **buf, int *buflen)
+{
+	prepend(buf, buflen, "\0", 1);
+	if (d_unlinked(path->dentry)) {
+		int error = prepend(buf, buflen, " (deleted)", 10);
+		if (error)
+			return error;
+	}
+
+	return prepend_path(path, root, buf, buflen);
+}
+
+static int prepend_unreachable(char **buffer, int *buflen)
+{
+	return prepend(buffer, buflen, "(unreachable)", 13);
 }
 
 /**
@@ -2000,9 +2042,10 @@ Elong:
  */
 char *d_path(const struct path *path, char *buf, int buflen)
 {
-	char *res;
+	char *res = buf + buflen;
 	struct path root;
 	struct path tmp;
+	int error;
 
 	/*
 	 * We have various synthetic filesystems that never get mounted.  On
@@ -2014,19 +2057,51 @@ char *d_path(const struct path *path, char *buf, int buflen)
 	if (path->dentry->d_op && path->dentry->d_op->d_dname)
 		return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
 
-	read_lock(&current->fs->lock);
-	root = current->fs->root;
-	path_get(&root);
-	read_unlock(&current->fs->lock);
+	get_fs_root(current->fs, &root);
 	spin_lock(&dcache_lock);
 	tmp = root;
-	res = __d_path(path, &tmp, buf, buflen);
+	error = path_with_deleted(path, &tmp, &res, &buflen);
+	if (error)
+		res = ERR_PTR(error);
 	spin_unlock(&dcache_lock);
 	path_put(&root);
 	return res;
 }
 EXPORT_SYMBOL(d_path);
 
+/**
+ * d_path_with_unreachable - return the path of a dentry
+ * @path: path to report
+ * @buf: buffer to return value in
+ * @buflen: buffer length
+ *
+ * The difference from d_path() is that this prepends "(unreachable)"
+ * to paths which are unreachable from the current process' root.
+ */
+char *d_path_with_unreachable(const struct path *path, char *buf, int buflen)
+{
+	char *res = buf + buflen;
+	struct path root;
+	struct path tmp;
+	int error;
+
+	if (path->dentry->d_op && path->dentry->d_op->d_dname)
+		return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
+
+	get_fs_root(current->fs, &root);
+	spin_lock(&dcache_lock);
+	tmp = root;
+	error = path_with_deleted(path, &tmp, &res, &buflen);
+	if (!error && !path_equal(&tmp, &root))
+		error = prepend_unreachable(&res, &buflen);
+	spin_unlock(&dcache_lock);
+	path_put(&root);
+	if (error)
+		res =  ERR_PTR(error);
+
+	return res;
+}
+
 /*
  * Helper function for dentry_operations.d_dname() members
  */
@@ -2129,27 +2204,30 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
 	if (!page)
 		return -ENOMEM;
 
-	read_lock(&current->fs->lock);
-	pwd = current->fs->pwd;
-	path_get(&pwd);
-	root = current->fs->root;
-	path_get(&root);
-	read_unlock(&current->fs->lock);
+	get_fs_root_and_pwd(current->fs, &root, &pwd);
 
 	error = -ENOENT;
 	spin_lock(&dcache_lock);
 	if (!d_unlinked(pwd.dentry)) {
 		unsigned long len;
 		struct path tmp = root;
-		char * cwd;
+		char *cwd = page + PAGE_SIZE;
+		int buflen = PAGE_SIZE;
 
-		cwd = __d_path(&pwd, &tmp, page, PAGE_SIZE);
+		prepend(&cwd, &buflen, "\0", 1);
+		error = prepend_path(&pwd, &tmp, &cwd, &buflen);
 		spin_unlock(&dcache_lock);
 
-		error = PTR_ERR(cwd);
-		if (IS_ERR(cwd))
+		if (error)
 			goto out;
 
+		/* Unreachable from current root */
+		if (!path_equal(&tmp, &root)) {
+			error = prepend_unreachable(&cwd, &buflen);
+			if (error)
+				goto out;
+		}
+
 		error = -ERANGE;
 		len = PAGE_SIZE + page - cwd;
 		if (len <= size) {
diff --git a/fs/fs_struct.c b/fs/fs_struct.c
index eee0590..1ee40eb 100644
--- a/fs/fs_struct.c
+++ b/fs/fs_struct.c
@@ -106,12 +106,7 @@ struct fs_struct *copy_fs_struct(struct fs_struct *old)
 		fs->in_exec = 0;
 		rwlock_init(&fs->lock);
 		fs->umask = old->umask;
-		read_lock(&old->lock);
-		fs->root = old->root;
-		path_get(&old->root);
-		fs->pwd = old->pwd;
-		path_get(&old->pwd);
-		read_unlock(&old->lock);
+		get_fs_root_and_pwd(old, &fs->root, &fs->pwd);
 	}
 	return fs;
 }
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index 6b4dcd4..5a44811 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -722,7 +722,12 @@ root_found:
 	}
 
 	s->s_magic = ISOFS_SUPER_MAGIC;
-	s->s_maxbytes = 0xffffffff; /* We can handle files up to 4 GB */
+
+	/*
+	 * With multi-extent files, file size is only limited by the maximum
+	 * size of a file system, which is 8 TB.
+	 */
+	s->s_maxbytes = 0x80000000000LL;
 
 	/*
 	 * The CDROM is read-only, has no nodes (devices) on it, and since
diff --git a/fs/namei.c b/fs/namei.c
index 13ff4ab..17ea76bf 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -483,13 +483,8 @@ ok:
 
 static __always_inline void set_root(struct nameidata *nd)
 {
-	if (!nd->root.mnt) {
-		struct fs_struct *fs = current->fs;
-		read_lock(&fs->lock);
-		nd->root = fs->root;
-		path_get(&nd->root);
-		read_unlock(&fs->lock);
-	}
+	if (!nd->root.mnt)
+		get_fs_root(current->fs, &nd->root);
 }
 
 static int link_path_walk(const char *, struct nameidata *);
@@ -1015,11 +1010,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, struct namei
 		nd->path = nd->root;
 		path_get(&nd->root);
 	} else if (dfd == AT_FDCWD) {
-		struct fs_struct *fs = current->fs;
-		read_lock(&fs->lock);
-		nd->path = fs->pwd;
-		path_get(&fs->pwd);
-		read_unlock(&fs->lock);
+		get_fs_pwd(current->fs, &nd->path);
 	} else {
 		struct dentry *dentry;
 
diff --git a/fs/namespace.c b/fs/namespace.c
index 66c4f7e..2e10cb1 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -788,7 +788,6 @@ static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)
 		{ MNT_NOATIME, ",noatime" },
 		{ MNT_NODIRATIME, ",nodiratime" },
 		{ MNT_RELATIME, ",relatime" },
-		{ MNT_STRICTATIME, ",strictatime" },
 		{ 0, NULL }
 	};
 	const struct proc_fs_info *fs_infop;
@@ -2213,10 +2212,7 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
 		goto out1;
 	}
 
-	read_lock(&current->fs->lock);
-	root = current->fs->root;
-	path_get(&current->fs->root);
-	read_unlock(&current->fs->lock);
+	get_fs_root(current->fs, &root);
 	down_write(&namespace_sem);
 	mutex_lock(&old.dentry->d_inode->i_mutex);
 	error = -EINVAL;
diff --git a/fs/proc/base.c b/fs/proc/base.c
index c806dfb..a1c43e7 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -149,18 +149,13 @@ static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
 	return count;
 }
 
-static int get_fs_path(struct task_struct *task, struct path *path, bool root)
+static int get_task_root(struct task_struct *task, struct path *root)
 {
-	struct fs_struct *fs;
 	int result = -ENOENT;
 
 	task_lock(task);
-	fs = task->fs;
-	if (fs) {
-		read_lock(&fs->lock);
-		*path = root ? fs->root : fs->pwd;
-		path_get(path);
-		read_unlock(&fs->lock);
+	if (task->fs) {
+		get_fs_root(task->fs, root);
 		result = 0;
 	}
 	task_unlock(task);
@@ -173,7 +168,12 @@ static int proc_cwd_link(struct inode *inode, struct path *path)
 	int result = -ENOENT;
 
 	if (task) {
-		result = get_fs_path(task, path, 0);
+		task_lock(task);
+		if (task->fs) {
+			get_fs_pwd(task->fs, path);
+			result = 0;
+		}
+		task_unlock(task);
 		put_task_struct(task);
 	}
 	return result;
@@ -185,7 +185,7 @@ static int proc_root_link(struct inode *inode, struct path *path)
 	int result = -ENOENT;
 
 	if (task) {
-		result = get_fs_path(task, path, 1);
+		result = get_task_root(task, path);
 		put_task_struct(task);
 	}
 	return result;
@@ -597,7 +597,7 @@ static int mounts_open_common(struct inode *inode, struct file *file,
 				get_mnt_ns(ns);
 		}
 		rcu_read_unlock();
-		if (ns && get_fs_path(task, &root, 1) == 0)
+		if (ns && get_task_root(task, &root) == 0)
 			ret = 0;
 		put_task_struct(task);
 	}
@@ -1526,7 +1526,7 @@ static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
 	if (!tmp)
 		return -ENOMEM;
 
-	pathname = d_path(path, tmp, PAGE_SIZE);
+	pathname = d_path_with_unreachable(path, tmp, PAGE_SIZE);
 	len = PTR_ERR(pathname);
 	if (IS_ERR(pathname))
 		goto out;
diff --git a/fs/sysv/super.c b/fs/sysv/super.c
index 85359a8..a0b0cda 100644
--- a/fs/sysv/super.c
+++ b/fs/sysv/super.c
@@ -24,7 +24,6 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/buffer_head.h>
-#include <linux/parser.h>
 #include "sysv.h"
 
 /*