[PATCH] ntfs cleanup

	ntfs_fill_super() and ntfs_read_inode_mount() cleaned up.  Removed
the kludges around the first iget() on NTFS.  Instead of playing with
(re)setting ->s_op we have the MFT_FILE inode set up by explicit new_inode()/
set ->i_ino/insert_inode_hash()/call ntfs_read_inode_mount() directly.
That kills the need of second super_operations and it allows to return
error from ntfs_read_inode_mount() without resorting to ugly "poisoning"
tricks.

fs/ntfs/inode.c

@@ -1310,7 +1310,7 @@ static int ntfs_read_locked_attr_inode(struct inode *base_vi, struct inode *vi)
  * This should work but there are two possible pit falls (see inline comments
  * below), but only time will tell if they are real pits or just smoke...
  */
-void ntfs_read_inode_mount(struct inode *vi)
+int ntfs_read_inode_mount(struct inode *vi)
 {
 	VCN next_vcn, last_vcn, highest_vcn;
 	s64 block;
@@ -1326,12 +1326,6 @@ void ntfs_read_inode_mount(struct inode *vi)
 
 	ntfs_debug("Entering.");
 
-	if (vi->i_ino != FILE_MFT) {
-		ntfs_error(sb, "Called for inode 0x%lx but only inode %d "
-				"allowed.", vi->i_ino, FILE_MFT);
-		goto err_out;
-	}
-
 	/* Initialize the ntfs specific part of @vi. */
 	ntfs_init_big_inode(vi);
 
@@ -1616,13 +1610,7 @@ void ntfs_read_inode_mount(struct inode *vi)
 			/*
 			 * We have got the first extent of the run_list for
 			 * $MFT which means it is now relatively safe to call
-			 * the normal ntfs_read_inode() function. Thus, take
-			 * us out of the calling chain. Also we need to do this
-			 * now because we need ntfs_read_inode() in place to
-			 * get at subsequent extents.
-			 */
-			sb->s_op = &ntfs_sops;
-			/*
+			 * the normal ntfs_read_inode() function.
 			 * Complete reading the inode, this will actually
 			 * re-read the mft record for $MFT, this time entering
 			 * it into the page cache with which we complete the
@@ -1649,8 +1637,8 @@ void ntfs_read_inode_mount(struct inode *vi)
 						"sourceforge.net");
 				put_attr_search_ctx(ctx);
 				/* Revert to the safe super operations. */
-				sb->s_op = &ntfs_mount_sops;
-				goto out_now;
+				ntfs_free(m);
+				return -1;
 			}
 			/*
 			 * Re-initialize some specifics about $MFT's inode as
@@ -1699,20 +1687,19 @@ void ntfs_read_inode_mount(struct inode *vi)
 	}
 	put_attr_search_ctx(ctx);
 	ntfs_debug("Done.");
-out_now:
 	ntfs_free(m);
-	return;
+	return 0;
+
 em_put_err_out:
 	ntfs_error(sb, "Couldn't find first extent of $DATA attribute in "
 			"attribute list. $MFT is corrupt. Run chkdsk.");
 put_err_out:
 	put_attr_search_ctx(ctx);
 err_out:
-	/* Make sure we revert to the safe super operations. */
-	sb->s_op = &ntfs_mount_sops;
 	ntfs_error(sb, "Failed. Marking inode as bad.");
 	make_bad_inode(vi);
-	goto out_now;
+	ntfs_free(m);
+	return -1;
 }
 
 /**

fs/ntfs/inode.h

@@ -269,7 +269,7 @@ extern ntfs_inode *ntfs_new_extent_inode(struct super_block *sb,
 		unsigned long mft_no);
 extern void ntfs_clear_extent_inode(ntfs_inode *ni);
 
-extern void ntfs_read_inode_mount(struct inode *vi);
+extern int ntfs_read_inode_mount(struct inode *vi);
 
 extern void ntfs_put_inode(struct inode *vi);
 

fs/ntfs/ntfs.h

@@ -61,8 +61,6 @@ extern kmem_cache_t *ntfs_attr_ctx_cache;
 
 /* The various operations structs defined throughout the driver files. */
 extern struct super_operations ntfs_sops;
-extern struct super_operations ntfs_mount_sops;
-
 extern struct address_space_operations ntfs_aops;
 extern struct address_space_operations ntfs_mft_aops;
 
@@ -75,14 +73,6 @@ extern struct inode_operations ntfs_dir_inode_ops;
 extern struct  file_operations ntfs_empty_file_ops;
 extern struct inode_operations ntfs_empty_inode_ops;
 
-/* Generic macros to convert pointers to values and vice versa. */
-#ifndef p2n
-#define p2n(p)		((ptrdiff_t)((ptrdiff_t*)(p)))
-#endif
-#ifndef n2p
-#define n2p(p)		((ptrdiff_t*)((ptrdiff_t)(p)))
-#endif
-
 /**
  * NTFS_SB - return the ntfs volume given a vfs super block
  * @sb:		VFS super block

fs/ntfs/super.c

@@ -1584,19 +1584,6 @@ static int ntfs_statfs(struct super_block *sb, struct kstatfs *sfs)
 	return 0;
 }
 
-/**
- * Super operations for mount time when we don't have enough setup to use the
- * proper functions.
- */
-struct super_operations ntfs_mount_sops = {
-	.alloc_inode	= ntfs_alloc_big_inode,	  /* VFS: Allocate new inode. */
-	.destroy_inode	= ntfs_destroy_big_inode, /* VFS: Deallocate inode. */
-	.read_inode	= ntfs_read_inode_mount,  /* VFS: Load inode from disk,
-						     called from iget(). */
-	.clear_inode	= ntfs_clear_big_inode,	  /* VFS: Called when inode is
-						     removed from memory. */
-};
-
 /**
  * The complete super operations.
  */
@@ -1814,28 +1801,20 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
 	 * the inode for $MFT which is sufficient to allow our normal inode
 	 * operations and associated address space operations to function.
 	 */
-	/*
-	 * Poison vol->mft_ino so we know whether iget() called into our
-	 * ntfs_read_inode_mount() method.
-	 */
-#define OGIN	((struct inode*)n2p(le32_to_cpu(0x4e49474f)))	/* OGIN */
-	vol->mft_ino = OGIN;
-	sb->s_op = &ntfs_mount_sops;
-	tmp_ino = iget(vol->sb, FILE_MFT);
-	if (!tmp_ino || tmp_ino != vol->mft_ino || is_bad_inode(tmp_ino)) {
+	sb->s_op = &ntfs_sops;
+	tmp_ino = new_inode(sb);
+	if (!tmp_ino) {
+		if (!silent)
+			ntfs_error(sb, "Failed to load essential metadata.");
+		goto err_out_now;
+	}
+	tmp_ino->i_ino = FILE_MFT;
+	insert_inode_hash(tmp_ino);
+	if (ntfs_read_inode_mount(tmp_ino) < 0) {
 		if (!silent)
 			ntfs_error(sb, "Failed to load essential metadata.");
-		if (tmp_ino && vol->mft_ino == OGIN)
-			ntfs_error(sb, "BUG: iget() did not call "
-					"ntfs_read_inode_mount() method!\n");
-		if (!tmp_ino)
-			goto cond_iput_mft_ino_err_out_now;
 		goto iput_tmp_ino_err_out_now;
 	}
-	/*
-	 * Note: sb->s_op has already been set to &ntfs_sops by our specialized
-	 * ntfs_read_inode_mount() method when it was invoked by iget().
-	 */
 	down(&ntfs_lock);
 	/*
 	 * The current mount is a compression user if the cluster size is
@@ -1931,12 +1910,10 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent)
 	up(&ntfs_lock);
 iput_tmp_ino_err_out_now:
 	iput(tmp_ino);
-cond_iput_mft_ino_err_out_now:
-	if (vol->mft_ino && vol->mft_ino != OGIN && vol->mft_ino != tmp_ino) {
+	if (vol->mft_ino && vol->mft_ino != tmp_ino) {
 		iput(vol->mft_ino);
 		vol->mft_ino = NULL;
 	}
-#undef OGIN
 	/*
 	 * This is needed to get ntfs_clear_extent_inode() called for each
 	 * inode we have ever called ntfs_iget()/iput() on, otherwise we A)