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

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

openpromfs_fill_super() returns any error incurred when getting the root inode
instead of ENOMEM (not that it currently incurs any other error).

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
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>

1 files changed, 30 insertions, 15 deletions

diff --git a/fs/openpromfs/inode.c b/fs/openpromfs/inode.c
index 6b7ff1618945..d17b4fd204e1 100644
--- a/fs/openpromfs/inode.c
+++ b/fs/openpromfs/inode.c
@@ -38,6 +38,8 @@ struct op_inode_info {
         union op_inode_data     u;
 };
 
+static struct inode *openprom_iget(struct super_block *sb, ino_t ino);
+
 static inline struct op_inode_info *OP_I(struct inode *inode)
 {
         return container_of(inode, struct op_inode_info, vfs_inode);
@@ -226,10 +228,10 @@ static struct dentry *openpromfs_lookup(struct inode *dir, struct dentry *dentry
         return ERR_PTR(-ENOENT);
 
 found:
-        inode = iget(dir->i_sb, ino);
+        inode = openprom_iget(dir->i_sb, ino);
         mutex_unlock(&op_mutex);
-        if (!inode)
-                return ERR_PTR(-EINVAL);
+        if (IS_ERR(inode))
+                return ERR_CAST(inode);
         ent_oi = OP_I(inode);
         ent_oi->type = ent_type;
         ent_oi->u = ent_data;
@@ -348,14 +350,23 @@ static void openprom_destroy_inode(struct inode *inode)
         kmem_cache_free(op_inode_cachep, OP_I(inode));
 }
 
-static void openprom_read_inode(struct inode * inode)
+static struct inode *openprom_iget(struct super_block *sb, ino_t ino)
 {
-        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
-        if (inode->i_ino == OPENPROM_ROOT_INO) {
-                inode->i_op = &openprom_inode_operations;
-                inode->i_fop = &openprom_operations;
-                inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
+        struct inode *inode;
+
+        inode = iget_locked(sb, ino);
+        if (!inode)
+                return ERR_PTR(-ENOMEM);
+        if (inode->i_state & I_NEW) {
+                inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+                if (inode->i_ino == OPENPROM_ROOT_INO) {
+                        inode->i_op = &openprom_inode_operations;
+                        inode->i_fop = &openprom_operations;
+                        inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
+                }
+                unlock_new_inode(inode);
         }
+        return inode;
 }
 
 static int openprom_remount(struct super_block *sb, int *flags, char *data)
@@ -367,7 +378,6 @@ static int openprom_remount(struct super_block *sb, int *flags, char *data)
 static const struct super_operations openprom_sops = {
         .alloc_inode    = openprom_alloc_inode,
         .destroy_inode  = openprom_destroy_inode,
-        .read_inode     = openprom_read_inode,
         .statfs         = simple_statfs,
         .remount_fs     = openprom_remount,
 };
@@ -376,6 +386,7 @@ static int openprom_fill_super(struct super_block *s, void *data, int silent)
 {
         struct inode *root_inode;
         struct op_inode_info *oi;
+        int ret;
 
         s->s_flags |= MS_NOATIME;
         s->s_blocksize = 1024;
@@ -383,9 +394,11 @@ static int openprom_fill_super(struct super_block *s, void *data, int silent)
         s->s_magic = OPENPROM_SUPER_MAGIC;
         s->s_op = &openprom_sops;
         s->s_time_gran = 1;
-        root_inode = iget(s, OPENPROM_ROOT_INO);
-        if (!root_inode)
+        root_inode = openprom_iget(s, OPENPROM_ROOT_INO);
+        if (IS_ERR(root_inode)) {
+                ret = PTR_ERR(root_inode);
                 goto out_no_root;
+        }
 
         oi = OP_I(root_inode);
         oi->type = op_inode_node;
@@ -393,13 +406,15 @@ static int openprom_fill_super(struct super_block *s, void *data, int silent)
 
         s->s_root = d_alloc_root(root_inode);
         if (!s->s_root)
-                goto out_no_root;
+                goto out_no_root_dentry;
         return 0;
 
+out_no_root_dentry:
+        iput(root_inode);
+        ret = -ENOMEM;
 out_no_root:
         printk("openprom_fill_super: get root inode failed\n");
-        iput(root_inode);
-        return -ENOMEM;
+        return ret;
 }
 
 static int openprom_get_sb(struct file_system_type *fs_type,