Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull the big VFS changes from Al Viro:
 "This one is *big* and changes quite a few things around VFS.  What's in there:

   - the first of two really major architecture changes - death to open
     intents.

     The former is finally there; it was very long in making, but with
     Miklos getting through really hard and messy final push in
     fs/namei.c, we finally have it.  Unlike his variant, this one
     doesn't introduce struct opendata; what we have instead is
     ->atomic_open() taking preallocated struct file * and passing
     everything via its fields.

     Instead of returning struct file *, it returns -E...  on error, 0
     on success and 1 in "deal with it yourself" case (e.g.  symlink
     found on server, etc.).

     See comments before fs/namei.c:atomic_open().  That made a lot of
     goodies finally possible and quite a few are in that pile:
     ->lookup(), ->d_revalidate() and ->create() do not get struct
     nameidata * anymore; ->lookup() and ->d_revalidate() get lookup
     flags instead, ->create() gets "do we want it exclusive" flag.

     With the introduction of new helper (kern_path_locked()) we are rid
     of all struct nameidata instances outside of fs/namei.c; it's still
     visible in namei.h, but not for long.  Come the next cycle,
     declaration will move either to fs/internal.h or to fs/namei.c
     itself.  [me, miklos, hch]

   - The second major change: behaviour of final fput().  Now we have
     __fput() done without any locks held by caller *and* not from deep
     in call stack.

     That obviously lifts a lot of constraints on the locking in there.
     Moreover, it's legal now to call fput() from atomic contexts (which
     has immediately simplified life for aio.c).  We also don't need
     anti-recursion logics in __scm_destroy() anymore.

     There is a price, though - the damn thing has become partially
     asynchronous.  For fput() from normal process we are guaranteed
     that pending __fput() will be done before the caller returns to
     userland, exits or gets stopped for ptrace.

     For kernel threads and atomic contexts it's done via
     schedule_work(), so theoretically we might need a way to make sure
     it's finished; so far only one such place had been found, but there
     might be more.

     There's flush_delayed_fput() (do all pending __fput()) and there's
     __fput_sync() (fput() analog doing __fput() immediately).  I hope
     we won't need them often; see warnings in fs/file_table.c for
     details.  [me, based on task_work series from Oleg merged last
     cycle]

   - sync series from Jan

   - large part of "death to sync_supers()" work from Artem; the only
     bits missing here are exofs and ext4 ones.  As far as I understand,
     those are going via the exofs and ext4 trees resp.; once they are
     in, we can put ->write_super() to the rest, along with the thread
     calling it.

   - preparatory bits from unionmount series (from dhowells).

   - assorted cleanups and fixes all over the place, as usual.

  This is not the last pile for this cycle; there's at least jlayton's
  ESTALE work and fsfreeze series (the latter - in dire need of fixes,
  so I'm not sure it'll make the cut this cycle).  I'll probably throw
  symlink/hardlink restrictions stuff from Kees into the next pile, too.
  Plus there's a lot of misc patches I hadn't thrown into that one -
  it's large enough as it is..."

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (127 commits)
  ext4: switch EXT4_IOC_RESIZE_FS to mnt_want_write_file()
  btrfs: switch btrfs_ioctl_balance() to mnt_want_write_file()
  switch dentry_open() to struct path, make it grab references itself
  spufs: shift dget/mntget towards dentry_open()
  zoran: don't bother with struct file * in zoran_map
  ecryptfs: don't reinvent the wheels, please - use struct completion
  don't expose I_NEW inodes via dentry->d_inode
  tidy up namei.c a bit
  unobfuscate follow_up() a bit
  ext3: pass custom EOF to generic_file_llseek_size()
  ext4: use core vfs llseek code for dir seeks
  vfs: allow custom EOF in generic_file_llseek code
  vfs: Avoid unnecessary WB_SYNC_NONE writeback during sys_sync and reorder sync passes
  vfs: Remove unnecessary flushing of block devices
  vfs: Make sys_sync writeout also block device inodes
  vfs: Create function for iterating over block devices
  vfs: Reorder operations during sys_sync
  quota: Move quota syncing to ->sync_fs method
  quota: Split dquot_quota_sync() to writeback and cache flushing part
  vfs: Move noop_backing_dev_info check from sync into writeback
  ...

1 files changed, 44 insertions, 47 deletions

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index b80bc846a15a..d17c20fd74e6 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -54,13 +54,12 @@ static struct inode *debugfs_get_inode(struct super_block *sb, umode_t mode, dev
                         break;
                 case S_IFLNK:
                         inode->i_op = &debugfs_link_operations;
-                        inode->i_fop = fops;
                         inode->i_private = data;
                         break;
                 case S_IFDIR:
                         inode->i_op = &simple_dir_inode_operations;
-                        inode->i_fop = fops ? fops : &simple_dir_operations;
-                        inode->i_private = data;
+                        inode->i_fop = &simple_dir_operations;
+                        inode->i_private = NULL;
 
                         /* directory inodes start off with i_nlink == 2
                          * (for "." entry) */
@@ -91,13 +90,12 @@ static int debugfs_mknod(struct inode *dir, struct dentry *dentry,
         return error;
 }
 
-static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode,
-                         void *data, const struct file_operations *fops)
+static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
         int res;
 
         mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
-        res = debugfs_mknod(dir, dentry, mode, 0, data, fops);
+        res = debugfs_mknod(dir, dentry, mode, 0, NULL, NULL);
         if (!res) {
                 inc_nlink(dir);
                 fsnotify_mkdir(dir, dentry);
@@ -106,10 +104,10 @@ static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode,
 }
 
 static int debugfs_link(struct inode *dir, struct dentry *dentry, umode_t mode,
-                        void *data, const struct file_operations *fops)
+                        void *data)
 {
         mode = (mode & S_IALLUGO) | S_IFLNK;
-        return debugfs_mknod(dir, dentry, mode, 0, data, fops);
+        return debugfs_mknod(dir, dentry, mode, 0, data, NULL);
 }
 
 static int debugfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
@@ -293,13 +291,19 @@ static struct file_system_type debug_fs_type = {
         .kill_sb =      kill_litter_super,
 };
 
-static int debugfs_create_by_name(const char *name, umode_t mode,
-                                  struct dentry *parent,
-                                  struct dentry **dentry,
-                                  void *data,
-                                  const struct file_operations *fops)
+struct dentry *__create_file(const char *name, umode_t mode,
+                                   struct dentry *parent, void *data,
+                                   const struct file_operations *fops)
 {
-        int error = 0;
+        struct dentry *dentry = NULL;
+        int error;
+
+        pr_debug("debugfs: creating file '%s'\n",name);
+
+        error = simple_pin_fs(&debug_fs_type, &debugfs_mount,
+                              &debugfs_mount_count);
+        if (error)
+                goto exit;
 
         /* If the parent is not specified, we create it in the root.
          * We need the root dentry to do this, which is in the super 
@@ -309,30 +313,35 @@ static int debugfs_create_by_name(const char *name, umode_t mode,
         if (!parent)
                 parent = debugfs_mount->mnt_root;
 
-        *dentry = NULL;
+        dentry = NULL;
         mutex_lock(&parent->d_inode->i_mutex);
-        *dentry = lookup_one_len(name, parent, strlen(name));
-        if (!IS_ERR(*dentry)) {
+        dentry = lookup_one_len(name, parent, strlen(name));
+        if (!IS_ERR(dentry)) {
                 switch (mode & S_IFMT) {
                 case S_IFDIR:
-                        error = debugfs_mkdir(parent->d_inode, *dentry, mode,
-                                              data, fops);
+                        error = debugfs_mkdir(parent->d_inode, dentry, mode);
+                                              
                         break;
                 case S_IFLNK:
-                        error = debugfs_link(parent->d_inode, *dentry, mode,
-                                             data, fops);
+                        error = debugfs_link(parent->d_inode, dentry, mode,
+                                             data);
                         break;
                 default:
-                        error = debugfs_create(parent->d_inode, *dentry, mode,
+                        error = debugfs_create(parent->d_inode, dentry, mode,
                                                data, fops);
                         break;
                 }
-                dput(*dentry);
+                dput(dentry);
         } else
-                error = PTR_ERR(*dentry);
+                error = PTR_ERR(dentry);
         mutex_unlock(&parent->d_inode->i_mutex);
 
-        return error;
+        if (error) {
+                dentry = NULL;
+                simple_release_fs(&debugfs_mount, &debugfs_mount_count);
+        }
+exit:
+        return dentry;
 }
 
 /**
@@ -365,25 +374,15 @@ struct dentry *debugfs_create_file(const char *name, umode_t mode,
                                    struct dentry *parent, void *data,
                                    const struct file_operations *fops)
 {
-        struct dentry *dentry = NULL;
-        int error;
-
-        pr_debug("debugfs: creating file '%s'\n",name);
-
-        error = simple_pin_fs(&debug_fs_type, &debugfs_mount,
-                              &debugfs_mount_count);
-        if (error)
-                goto exit;
-
-        error = debugfs_create_by_name(name, mode, parent, &dentry,
-                                       data, fops);
-        if (error) {
-                dentry = NULL;
-                simple_release_fs(&debugfs_mount, &debugfs_mount_count);
-                goto exit;
+        switch (mode & S_IFMT) {
+        case S_IFREG:
+        case 0:
+                break;
+        default:
+                BUG();
         }
-exit:
-        return dentry;
+
+        return __create_file(name, mode, parent, data, fops);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_file);
 
@@ -407,8 +406,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_file);
  */
 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
 {
-        return debugfs_create_file(name, 
-                                   S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
+        return __create_file(name, S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
                                    parent, NULL, NULL);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_dir);
@@ -446,8 +444,7 @@ struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
         if (!link)
                 return NULL;
 
-        result = debugfs_create_file(name, S_IFLNK | S_IRWXUGO, parent, link,
-                                     NULL);
+        result = __create_file(name, S_IFLNK | S_IRWXUGO, parent, link, NULL);
         if (!result)
                 kfree(link);
         return result;