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:
  [patch 2/3] vfs: dcache cleanups
  [patch 1/3] vfs: dcache sparse fixes
  [patch 3/3] vfs: make d_path() consistent across mount operations
  [patch 4/4] flock: remove unused fields from file_lock_operations
  [patch 3/4] vfs: fix ERR_PTR abuse in generic_readlink
  [patch 2/4] fs: make struct file arg to d_path const
  [patch 1/4] vfs: path_{get,put}() cleanups
  [patch for 2.6.26 4/4] vfs: utimensat(): fix write access check for futimens()
  [patch for 2.6.26 3/4] vfs: utimensat(): fix error checking for {UTIME_NOW,UTIME_OMIT} case
  [patch for 2.6.26 1/4] vfs: utimensat(): ignore tv_sec if tv_nsec == UTIME_OMIT or UTIME_NOW
  [patch for 2.6.26 2/4] vfs: utimensat(): be consistent with utime() for immutable and append-only files
  [PATCH] fix cgroup-inflicted breakage in block_dev.c

6 files changed, 88 insertions, 91 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 470c10ceb0fb..10d8a0aa871a 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -931,8 +931,16 @@ static int do_open(struct block_device *bdev, struct file *file, int for_part)
         struct gendisk *disk;
         int ret;
         int part;
+        int perm = 0;
 
-        ret = devcgroup_inode_permission(bdev->bd_inode, file->f_mode);
+        if (file->f_mode & FMODE_READ)
+                perm |= MAY_READ;
+        if (file->f_mode & FMODE_WRITE)
+                perm |= MAY_WRITE;
+        /*
+         * hooks: /n/, see "layering violations".
+         */
+        ret = devcgroup_inode_permission(bdev->bd_inode, perm);
         if (ret != 0)
                 return ret;
 
diff --git a/fs/dcache.c b/fs/dcache.c
index 3ee588d5f585..6068c25b393c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -17,6 +17,7 @@
 #include <linux/syscalls.h>
 #include <linux/string.h>
 #include <linux/mm.h>
+#include <linux/fdtable.h>
 #include <linux/fs.h>
 #include <linux/fsnotify.h>
 #include <linux/slab.h>
@@ -106,9 +107,10 @@ static void dentry_lru_remove(struct dentry *dentry)
 /*
  * Release the dentry's inode, using the filesystem
  * d_iput() operation if defined.
- * Called with dcache_lock and per dentry lock held, drops both.
  */
 static void dentry_iput(struct dentry * dentry)
+        __releases(dentry->d_lock)
+        __releases(dcache_lock)
 {
         struct inode *inode = dentry->d_inode;
         if (inode) {
@@ -132,12 +134,13 @@ static void dentry_iput(struct dentry * dentry)
  * d_kill - kill dentry and return parent
  * @dentry: dentry to kill
  *
- * Called with dcache_lock and d_lock, releases both.  The dentry must
- * already be unhashed and removed from the LRU.
+ * The dentry must already be unhashed and removed from the LRU.
  *
  * If this is the root of the dentry tree, return NULL.
  */
 static struct dentry *d_kill(struct dentry *dentry)
+        __releases(dentry->d_lock)
+        __releases(dcache_lock)
 {
         struct dentry *parent;
 
@@ -383,11 +386,11 @@ restart:
  * Try to prune ancestors as well.  This is necessary to prevent
  * quadratic behavior of shrink_dcache_parent(), but is also expected
  * to be beneficial in reducing dentry cache fragmentation.
- *
- * Called with dcache_lock, drops it and then regains.
- * Called with dentry->d_lock held, drops it.
  */
 static void prune_one_dentry(struct dentry * dentry)
+        __releases(dentry->d_lock)
+        __releases(dcache_lock)
+        __acquires(dcache_lock)
 {
         __d_drop(dentry);
         dentry = d_kill(dentry);
@@ -1604,10 +1607,9 @@ static int d_isparent(struct dentry *p1, struct dentry *p2)
  *
  * Note: If ever the locking in lock_rename() changes, then please
  * remember to update this too...
- *
- * On return, dcache_lock will have been unlocked.
  */
 static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
+        __releases(dcache_lock)
 {
         struct mutex *m1 = NULL, *m2 = NULL;
         struct dentry *ret;
@@ -1743,11 +1745,9 @@ out_nolock:
 shouldnt_be_hashed:
         spin_unlock(&dcache_lock);
         BUG();
-        goto shouldnt_be_hashed;
 }
 
-static int prepend(char **buffer, int *buflen, const char *str,
-                          int namelen)
+static int prepend(char **buffer, int *buflen, const char *str, int namelen)
 {
         *buflen -= namelen;
         if (*buflen < 0)
@@ -1757,8 +1757,13 @@ static int prepend(char **buffer, int *buflen, const char *str,
         return 0;
 }
 
+static int prepend_name(char **buffer, int *buflen, struct qstr *name)
+{
+        return prepend(buffer, buflen, name->name, name->len);
+}
+
 /**
- * d_path - return the path of a dentry
+ * __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
@@ -1779,9 +1784,10 @@ char *__d_path(const struct path *path, struct path *root,
 {
         struct dentry *dentry = path->dentry;
         struct vfsmount *vfsmnt = path->mnt;
-        char * end = buffer+buflen;
-        char * retval;
+        char *end = buffer + buflen;
+        char *retval;
 
+        spin_lock(&vfsmount_lock);
         prepend(&end, &buflen, "\0", 1);
         if (!IS_ROOT(dentry) && d_unhashed(dentry) &&
                 (prepend(&end, &buflen, " (deleted)", 10) != 0))
@@ -1800,38 +1806,37 @@ char *__d_path(const struct path *path, struct path *root,
                         break;
                 if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
                         /* Global root? */
-                        spin_lock(&vfsmount_lock);
                         if (vfsmnt->mnt_parent == vfsmnt) {
-                                spin_unlock(&vfsmount_lock);
                                 goto global_root;
                         }
                         dentry = vfsmnt->mnt_mountpoint;
                         vfsmnt = vfsmnt->mnt_parent;
-                        spin_unlock(&vfsmount_lock);
                         continue;
                 }
                 parent = dentry->d_parent;
                 prefetch(parent);
-                if ((prepend(&end, &buflen, dentry->d_name.name,
-                                dentry->d_name.len) != 0) ||
+                if ((prepend_name(&end, &buflen, &dentry->d_name) != 0) ||
                     (prepend(&end, &buflen, "/", 1) != 0))
                         goto Elong;
                 retval = end;
                 dentry = parent;
         }
 
+out:
+        spin_unlock(&vfsmount_lock);
         return retval;
 
 global_root:
         retval += 1;    /* hit the slash */
-        if (prepend(&retval, &buflen, dentry->d_name.name,
-                    dentry->d_name.len) != 0)
+        if (prepend_name(&retval, &buflen, &dentry->d_name) != 0)
                 goto Elong;
         root->mnt = vfsmnt;
         root->dentry = dentry;
-        return retval;
+        goto out;
+
 Elong:
-        return ERR_PTR(-ENAMETOOLONG);
+        retval = ERR_PTR(-ENAMETOOLONG);
+        goto out;
 }
 
 /**
@@ -1845,9 +1850,9 @@ Elong:
  *
  * Returns the buffer or an error code if the path was too long.
  *
- * "buflen" should be positive. Caller holds the dcache_lock.
+ * "buflen" should be positive.
  */
-char *d_path(struct path *path, char *buf, int buflen)
+char *d_path(const struct path *path, char *buf, int buflen)
 {
         char *res;
         struct path root;
@@ -1915,16 +1920,11 @@ char *dentry_path(struct dentry *dentry, char *buf, int buflen)
         retval = end-1;
         *retval = '/';
 
-        for (;;) {
-                struct dentry *parent;
-                if (IS_ROOT(dentry))
-                        break;
+        while (!IS_ROOT(dentry)) {
+                struct dentry *parent = dentry->d_parent;
 
-                parent = dentry->d_parent;
                 prefetch(parent);
-
-                if ((prepend(&end, &buflen, dentry->d_name.name,
-                                dentry->d_name.len) != 0) ||
+                if ((prepend_name(&end, &buflen, &dentry->d_name) != 0) ||
                     (prepend(&end, &buflen, "/", 1) != 0))
                         goto Elong;
 
@@ -1975,7 +1975,7 @@ asmlinkage long sys_getcwd(char __user *buf, unsigned long size)
         error = -ENOENT;
         /* Has the current directory has been unlinked? */
         spin_lock(&dcache_lock);
-        if (pwd.dentry->d_parent == pwd.dentry || !d_unhashed(pwd.dentry)) {
+        if (IS_ROOT(pwd.dentry) || !d_unhashed(pwd.dentry)) {
                 unsigned long len;
                 struct path tmp = root;
                 char * cwd;
diff --git a/fs/locks.c b/fs/locks.c
index 11dbf08651b7..dce8c747371c 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -561,9 +561,6 @@ static void locks_insert_lock(struct file_lock **pos, struct file_lock *fl)
         /* insert into file's list */
         fl->fl_next = *pos;
         *pos = fl;
-
-        if (fl->fl_ops && fl->fl_ops->fl_insert)
-                fl->fl_ops->fl_insert(fl);
 }
 
 /*
@@ -586,9 +583,6 @@ static void locks_delete_lock(struct file_lock **thisfl_p)
                 fl->fl_fasync = NULL;
         }
 
-        if (fl->fl_ops && fl->fl_ops->fl_remove)
-                fl->fl_ops->fl_remove(fl);
-
         if (fl->fl_nspid) {
                 put_pid(fl->fl_nspid);
                 fl->fl_nspid = NULL;
diff --git a/fs/namei.c b/fs/namei.c
index c7e43536c49a..01e67dddcc3d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -581,15 +581,13 @@ static __always_inline int link_path_walk(const char *name, struct nameidata *nd
         int result;
 
         /* make sure the stuff we saved doesn't go away */
-        dget(save.dentry);
-        mntget(save.mnt);
+        path_get(&save);
 
         result = __link_path_walk(name, nd);
         if (result == -ESTALE) {
                 /* nd->path had been dropped */
                 nd->path = save;
-                dget(nd->path.dentry);
-                mntget(nd->path.mnt);
+                path_get(&nd->path);
                 nd->flags |= LOOKUP_REVAL;
                 result = __link_path_walk(name, nd);
         }
@@ -1216,8 +1214,9 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
         nd->flags = flags;
         nd->depth = 0;
 
-        nd->path.mnt = mntget(mnt);
-        nd->path.dentry = dget(dentry);
+        nd->path.dentry = dentry;
+        nd->path.mnt = mnt;
+        path_get(&nd->path);
 
         retval = path_walk(name, nd);
         if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry &&
@@ -2857,16 +2856,17 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 {
         struct nameidata nd;
         void *cookie;
+        int res;
 
         nd.depth = 0;
         cookie = dentry->d_inode->i_op->follow_link(dentry, &nd);
-        if (!IS_ERR(cookie)) {
-                int res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd));
-                if (dentry->d_inode->i_op->put_link)
-                        dentry->d_inode->i_op->put_link(dentry, &nd, cookie);
-                cookie = ERR_PTR(res);
-        }
-        return PTR_ERR(cookie);
+        if (IS_ERR(cookie))
+                return PTR_ERR(cookie);
+
+        res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd));
+        if (dentry->d_inode->i_op->put_link)
+                dentry->d_inode->i_op->put_link(dentry, &nd, cookie);
+        return res;
 }
 
 int vfs_follow_link(struct nameidata *nd, const char *link)
diff --git a/fs/pipe.c b/fs/pipe.c
index ec228bc9f882..700f4e0d9572 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1003,8 +1003,7 @@ struct file *create_write_pipe(void)
 void free_write_pipe(struct file *f)
 {
         free_pipe_info(f->f_dentry->d_inode);
-        dput(f->f_path.dentry);
-        mntput(f->f_path.mnt);
+        path_put(&f->f_path);
         put_filp(f);
 }
 
@@ -1015,8 +1014,8 @@ struct file *create_read_pipe(struct file *wrf)
                 return ERR_PTR(-ENFILE);
 
         /* Grab pipe from the writer */
-        f->f_path.mnt = mntget(wrf->f_path.mnt);
-        f->f_path.dentry = dget(wrf->f_path.dentry);
+        f->f_path = wrf->f_path;
+        path_get(&wrf->f_path);
         f->f_mapping = wrf->f_path.dentry->d_inode->i_mapping;
 
         f->f_pos = 0;
@@ -1068,8 +1067,7 @@ int do_pipe(int *fd)
  err_fdr:
         put_unused_fd(fdr);
  err_read_pipe:
-        dput(fr->f_dentry);
-        mntput(fr->f_vfsmnt);
+        path_put(&fr->f_path);
         put_filp(fr);
  err_write_pipe:
         free_write_pipe(fw);
diff --git a/fs/utimes.c b/fs/utimes.c
index af059d5cb485..b6b664e7145e 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -40,14 +40,9 @@ asmlinkage long sys_utime(char __user *filename, struct utimbuf __user *times)
 
 #endif
 
-static bool nsec_special(long nsec)
-{
-        return nsec == UTIME_OMIT || nsec == UTIME_NOW;
-}
-
 static bool nsec_valid(long nsec)
 {
-        if (nsec_special(nsec))
+        if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
                 return true;
 
         return nsec >= 0 && nsec <= 999999999;
@@ -102,7 +97,11 @@ long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags
         if (error)
                 goto dput_and_out;
 
-        /* Don't worry, the checks are done in inode_change_ok() */
+        if (times && times[0].tv_nsec == UTIME_NOW &&
+                     times[1].tv_nsec == UTIME_NOW)
+                times = NULL;
+
+        /* In most cases, the checks are done in inode_change_ok() */
         newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
         if (times) {
                 error = -EPERM;
@@ -124,28 +123,34 @@ long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags
                         newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
                         newattrs.ia_valid |= ATTR_MTIME_SET;
                 }
-        }
 
-        /*
-         * If times is NULL or both times are either UTIME_OMIT or
-         * UTIME_NOW, then need to check permissions, because
-         * inode_change_ok() won't do it.
-         */
-        if (!times || (nsec_special(times[0].tv_nsec) &&
-                       nsec_special(times[1].tv_nsec))) {
+                /*
+                 * For the UTIME_OMIT/UTIME_NOW and UTIME_NOW/UTIME_OMIT
+                 * cases, we need to make an extra check that is not done by
+                 * inode_change_ok().
+                 */
+                if (((times[0].tv_nsec == UTIME_NOW &&
+                            times[1].tv_nsec == UTIME_OMIT)
+                     ||
+                     (times[0].tv_nsec == UTIME_OMIT &&
+                            times[1].tv_nsec == UTIME_NOW))
+                    && !is_owner_or_cap(inode))
+                        goto mnt_drop_write_and_out;
+        } else {
+
+                /*
+                 * If times is NULL (or both times are UTIME_NOW),
+                 * then we need to check permissions, because
+                 * inode_change_ok() won't do it.
+                 */
                 error = -EACCES;
                 if (IS_IMMUTABLE(inode))
                         goto mnt_drop_write_and_out;
 
                 if (!is_owner_or_cap(inode)) {
-                        if (f) {
-                                if (!(f->f_mode & FMODE_WRITE))
-                                        goto mnt_drop_write_and_out;
-                        } else {
-                                error = vfs_permission(&nd, MAY_WRITE);
-                                if (error)
-                                        goto mnt_drop_write_and_out;
-                        }
+                        error = permission(inode, MAY_WRITE, NULL);
+                        if (error)
+                                goto mnt_drop_write_and_out;
                 }
         }
         mutex_lock(&inode->i_mutex);
@@ -169,14 +174,6 @@ asmlinkage long sys_utimensat(int dfd, char __user *filename, struct timespec __
         if (utimes) {
                 if (copy_from_user(&tstimes, utimes, sizeof(tstimes)))
                         return -EFAULT;
-                if ((tstimes[0].tv_nsec == UTIME_OMIT ||
-                     tstimes[0].tv_nsec == UTIME_NOW) &&
-                    tstimes[0].tv_sec != 0)
-                        return -EINVAL;
-                if ((tstimes[1].tv_nsec == UTIME_OMIT ||
-                     tstimes[1].tv_nsec == UTIME_NOW) &&
-                    tstimes[1].tv_sec != 0)
-                        return -EINVAL;
 
                 /* Nothing to do, we must not even check the path.  */
                 if (tstimes[0].tv_nsec == UTIME_OMIT &&