iget: stop EXT4 from using iget() and read_inode()

Stop the EXT4 filesystem from using iget() and read_inode().  Replace
ext4_read_inode() with ext4_iget(), and call that instead of iget().
ext4_iget() then uses iget_locked() directly and returns a proper error code
instead of an inode in the event of an error.

ext4_fill_super() returns any error incurred when getting the root inode
instead of EINVAL.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
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, 19 insertions, 6 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 0e9055cf700e..f4e387452246 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2680,21 +2680,31 @@ static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
         }
 }
 
-void ext4_read_inode(struct inode * inode)
+struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 {
         struct ext4_iloc iloc;
         struct ext4_inode *raw_inode;
-        struct ext4_inode_info *ei = EXT4_I(inode);
+        struct ext4_inode_info *ei;
         struct buffer_head *bh;
+        struct inode *inode;
+        long ret;
         int block;
 
+        inode = iget_locked(sb, ino);
+        if (!inode)
+                return ERR_PTR(-ENOMEM);
+        if (!(inode->i_state & I_NEW))
+                return inode;
+
+        ei = EXT4_I(inode);
 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
         ei->i_acl = EXT4_ACL_NOT_CACHED;
         ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 #endif
         ei->i_block_alloc_info = NULL;
 
-        if (__ext4_get_inode_loc(inode, &iloc, 0))
+        ret = __ext4_get_inode_loc(inode, &iloc, 0);
+        if (ret < 0)
                 goto bad_inode;
         bh = iloc.bh;
         raw_inode = ext4_raw_inode(&iloc);
@@ -2720,6 +2730,7 @@ void ext4_read_inode(struct inode * inode)
                     !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
                         /* this inode is deleted */
                         brelse (bh);
+                        ret = -ESTALE;
                         goto bad_inode;
                 }
                 /* The only unlinked inodes we let through here have
@@ -2758,6 +2769,7 @@ void ext4_read_inode(struct inode * inode)
                 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
                     EXT4_INODE_SIZE(inode->i_sb)) {
                         brelse (bh);
+                        ret = -EIO;
                         goto bad_inode;
                 }
                 if (ei->i_extra_isize == 0) {
@@ -2811,11 +2823,12 @@ void ext4_read_inode(struct inode * inode)
         }
         brelse (iloc.bh);
         ext4_set_inode_flags(inode);
-        return;
+        unlock_new_inode(inode);
+        return inode;
 
 bad_inode:
-        make_bad_inode(inode);
-        return;
+        iget_failed(inode);
+        return ERR_PTR(ret);
 }
 
 static int ext4_inode_blocks_set(handle_t *handle,