iget: stop BEFS from using iget() and read_inode()

Stop the BEFS filesystem from using iget() and read_inode().  Replace
befs_read_inode() with befs_iget(), and call that instead of iget().
befs_iget() then uses iget_locked() directly and returns a proper error code
instead of an inode in the event of an error.

befs_fill_super() returns any error incurred when getting the root inode
instead of EINVAL.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Will Dyson <will_dyson@pobox.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/befs/linuxvfs.c

@@ -35,7 +35,7 @@ static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
 static int befs_readpage(struct file *file, struct page *page);
 static sector_t befs_bmap(struct address_space *mapping, sector_t block);
 static struct dentry *befs_lookup(struct inode *, struct dentry *, struct nameidata *);
-static void befs_read_inode(struct inode *ino);
+static struct inode *befs_iget(struct super_block *, unsigned long);
 static struct inode *befs_alloc_inode(struct super_block *sb);
 static void befs_destroy_inode(struct inode *inode);
 static int befs_init_inodecache(void);
@@ -52,7 +52,6 @@ static int befs_statfs(struct dentry *, struct kstatfs *);
 static int parse_options(char *, befs_mount_options *);
 
 static const struct super_operations befs_sops = {
-	.read_inode	= befs_read_inode,	/* initialize & read inode */
 	.alloc_inode	= befs_alloc_inode,	/* allocate a new inode */
 	.destroy_inode	= befs_destroy_inode, /* deallocate an inode */
 	.put_super	= befs_put_super,	/* uninit super */
@@ -198,9 +197,9 @@ befs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 		return ERR_PTR(-ENODATA);
 	}
 
-	inode = iget(dir->i_sb, (ino_t) offset);
-	if (!inode)
-		return ERR_PTR(-EACCES);
+	inode = befs_iget(dir->i_sb, (ino_t) offset);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
 
 	d_add(dentry, inode);
 
@@ -296,17 +295,23 @@ static void init_once(struct kmem_cache *cachep, void *foo)
 	inode_init_once(&bi->vfs_inode);
 }
 
-static void
-befs_read_inode(struct inode *inode)
+static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
 {
 	struct buffer_head *bh = NULL;
 	befs_inode *raw_inode = NULL;
 
-	struct super_block *sb = inode->i_sb;
 	befs_sb_info *befs_sb = BEFS_SB(sb);
 	befs_inode_info *befs_ino = NULL;
+	struct inode *inode;
+	long ret = -EIO;
 
-	befs_debug(sb, "---> befs_read_inode() " "inode = %lu", inode->i_ino);
+	befs_debug(sb, "---> befs_read_inode() " "inode = %lu", ino);
+
+	inode = iget_locked(sb, ino);
+	if (IS_ERR(inode))
+		return inode;
+	if (!(inode->i_state & I_NEW))
+		return inode;
 
 	befs_ino = BEFS_I(inode);
 
@@ -402,15 +407,16 @@ befs_read_inode(struct inode *inode)
 
 	brelse(bh);
 	befs_debug(sb, "<--- befs_read_inode()");
-	return;
+	unlock_new_inode(inode);
+	return inode;
 
       unacquire_bh:
 	brelse(bh);
 
       unacquire_none:
-	make_bad_inode(inode);
+	iget_failed(inode);
 	befs_debug(sb, "<--- befs_read_inode() - Bad inode");
-	return;
+	return ERR_PTR(ret);
 }
 
 /* Initialize the inode cache. Called at fs setup.
@@ -752,6 +758,7 @@ befs_fill_super(struct super_block *sb, void *data, int silent)
 	befs_sb_info *befs_sb;
 	befs_super_block *disk_sb;
 	struct inode *root;
+	long ret = -EINVAL;
 
 	const unsigned long sb_block = 0;
 	const off_t x86_sb_off = 512;
@@ -833,7 +840,11 @@ befs_fill_super(struct super_block *sb, void *data, int silent)
 	/* Set real blocksize of fs */
 	sb_set_blocksize(sb, (ulong) befs_sb->block_size);
 	sb->s_op = (struct super_operations *) &befs_sops;
-	root = iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
+	root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
+	if (IS_ERR(root)) {
+		ret = PTR_ERR(root);
+		goto unacquire_priv_sbp;
+	}
 	sb->s_root = d_alloc_root(root);
 	if (!sb->s_root) {
 		iput(root);
@@ -868,7 +879,7 @@ befs_fill_super(struct super_block *sb, void *data, int silent)
 
       unacquire_none:
 	sb->s_fs_info = NULL;
-	return -EINVAL;
+	return ret;
 }
 
 static int