Merge tag 'pull-mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs mount updates from Al Viro:
 "Several piles this cycle, this mount-related one being the largest and
  trickiest:

   - saner handling of guards in fs/namespace.c, getting rid of
     needlessly strong locking in some of the users

   - lock_mount() calling conventions change - have it set the
     environment for attaching to given location, storing the results in
     caller-supplied object, without altering the passed struct path.

     Make unlock_mount() called as __cleanup for those objects. It's not
     exactly guard(), but similar to it

   - MNT_WRITE_HOLD done right.

     mnt_hold_writers() does *not* mess with ->mnt_flags anymore, so
     insertion of a new mount into ->s_mounts of underlying superblock
     does not, in itself, expose ->mnt_flags of that mount to concurrent
     modifications

   - getting rid of pathological cases when umount() spends quadratic
     time removing the victims from propagation graph - part of that had
     been dealt with last cycle, this should finish it

   - a bunch of stuff constified

   - assorted cleanups

* tag 'pull-mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits)
  constify {__,}mnt_is_readonly()
  WRITE_HOLD machinery: no need for to bump mount_lock seqcount
  struct mount: relocate MNT_WRITE_HOLD bit
  preparations to taking MNT_WRITE_HOLD out of ->mnt_flags
  setup_mnt(): primitive for connecting a mount to filesystem
  simplify the callers of mnt_unhold_writers()
  copy_mnt_ns(): use guards
  copy_mnt_ns(): use the regular mechanism for freeing empty mnt_ns on failure
  open_detached_copy(): separate creation of namespace into helper
  open_detached_copy(): don't bother with mount_lock_hash()
  path_has_submounts(): use guard(mount_locked_reader)
  fs/namespace.c: sanitize descriptions for {__,}lookup_mnt()
  ecryptfs: get rid of pointless mount references in ecryptfs dentries
  umount_tree(): take all victims out of propagation graph at once
  do_mount(): use __free(path_put)
  do_move_mount_old(): use __free(path_put)
  constify can_move_mount_beneath() arguments
  path_umount(): constify struct path argument
  may_copy_tree(), __do_loopback(): constify struct path argument
  path_mount(): constify struct path argument
  ...

1 files changed, 6 insertions, 18 deletions

diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index eab1beb846d3..16ea14dd2c62 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -106,15 +106,14 @@ static int ecryptfs_init_lower_file(struct dentry *dentry,
 				    struct file **lower_file)
 {
 	const struct cred *cred = current_cred();
-	const struct path *path = ecryptfs_dentry_to_lower_path(dentry);
+	struct path path = ecryptfs_lower_path(dentry);
 	int rc;
 
-	rc = ecryptfs_privileged_open(lower_file, path->dentry, path->mnt,
-				      cred);
+	rc = ecryptfs_privileged_open(lower_file, path.dentry, path.mnt, cred);
 	if (rc) {
 		printk(KERN_ERR "Error opening lower file "
 		       "for lower_dentry [0x%p] and lower_mnt [0x%p]; "
-		       "rc = [%d]\n", path->dentry, path->mnt, rc);
+		       "rc = [%d]\n", path.dentry, path.mnt, rc);
 		(*lower_file) = NULL;
 	}
 	return rc;
@@ -437,7 +436,6 @@ static int ecryptfs_get_tree(struct fs_context *fc)
 	struct ecryptfs_fs_context *ctx = fc->fs_private;
 	struct ecryptfs_sb_info *sbi = fc->s_fs_info;
 	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
-	struct ecryptfs_dentry_info *root_info;
 	const char *err = "Getting sb failed";
 	struct inode *inode;
 	struct path path;
@@ -543,14 +541,8 @@ static int ecryptfs_get_tree(struct fs_context *fc)
 		goto out_free;
 	}
 
-	rc = -ENOMEM;
-	root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
-	if (!root_info)
-		goto out_free;
-
-	/* ->kill_sb() will take care of root_info */
-	ecryptfs_set_dentry_private(s->s_root, root_info);
-	root_info->lower_path = path;
+	ecryptfs_set_dentry_lower(s->s_root, path.dentry);
+	ecryptfs_superblock_to_private(s)->lower_mnt = path.mnt;
 
 	s->s_flags |= SB_ACTIVE;
 	fc->root = dget(s->s_root);
@@ -580,6 +572,7 @@ static void ecryptfs_kill_block_super(struct super_block *sb)
 	kill_anon_super(sb);
 	if (!sb_info)
 		return;
+	mntput(sb_info->lower_mnt);
 	ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
 	kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
 }
@@ -668,11 +661,6 @@ static struct ecryptfs_cache_info {
 		.size = sizeof(struct ecryptfs_file_info),
 	},
 	{
-		.cache = &ecryptfs_dentry_info_cache,
-		.name = "ecryptfs_dentry_info_cache",
-		.size = sizeof(struct ecryptfs_dentry_info),
-	},
-	{
 		.cache = &ecryptfs_inode_info_cache,
 		.name = "ecryptfs_inode_cache",
 		.size = sizeof(struct ecryptfs_inode_info),