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

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

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Ian Kent <raven@themaw.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>
diff --git a/fs/autofs/root.c b/fs/autofs/root.c
index 5efff3c..8aacade 100644
--- a/fs/autofs/root.c
+++ b/fs/autofs/root.c
@@ -114,8 +114,8 @@
 	dentry->d_time = (unsigned long) ent;
 	
 	if (!dentry->d_inode) {
-		inode = iget(sb, ent->ino);
-		if (!inode) {
+		inode = autofs_iget(sb, ent->ino);
+		if (IS_ERR(inode)) {
 			/* Failed, but leave pending for next time */
 			return 1;
 		}
@@ -274,6 +274,7 @@
 	unsigned int n;
 	int slsize;
 	struct autofs_symlink *sl;
+	struct inode *inode;
 
 	DPRINTK(("autofs_root_symlink: %s <- ", symname));
 	autofs_say(dentry->d_name.name,dentry->d_name.len);
@@ -331,7 +332,12 @@
 	ent->dentry = NULL;	/* We don't keep the dentry for symlinks */
 
 	autofs_hash_insert(dh,ent);
-	d_instantiate(dentry, iget(dir->i_sb,ent->ino));
+
+	inode = autofs_iget(dir->i_sb, ent->ino);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	d_instantiate(dentry, inode);
 	unlock_kernel();
 	return 0;
 }
@@ -428,6 +434,7 @@
 	struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb);
 	struct autofs_dirhash *dh = &sbi->dirhash;
 	struct autofs_dir_ent *ent;
+	struct inode *inode;
 	ino_t ino;
 
 	lock_kernel();
@@ -469,7 +476,14 @@
 	autofs_hash_insert(dh,ent);
 
 	inc_nlink(dir);
-	d_instantiate(dentry, iget(dir->i_sb,ino));
+
+	inode = autofs_iget(dir->i_sb, ino);
+	if (IS_ERR(inode)) {
+		drop_nlink(dir);
+		return PTR_ERR(inode);
+	}
+
+	d_instantiate(dentry, inode);
 	unlock_kernel();
 
 	return 0;