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 d97c34a24f7a..c7c23eab9440 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 24eb0d37241a..727caedcdd92 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 9f2c13417969..166d35d56868 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 eee059052db5..1ee40eb9a2c0 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 6b4dcd4f2943..5a44811b5027 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 13ff4abdbdca..17ea76bf2fbe 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 66c4f7e781cb..2e10cb19c5b0 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 c806dfb24e08..a1c43e7c8a7b 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 85359a8df605..a0b0cda6927e 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"
 
 /*