iget: stop EXT2 from using iget() and read_inode()

Stop the EXT2 filesystem from using iget() and read_inode().  Replace
ext2_read_inode() with ext2_iget(), and call that instead of iget().
ext2_iget() then uses iget_locked() directly and returns a proper error code
instead of an inode in the event of an error.

ext2_fill_super() returns any error incurred when getting the root inode
instead of EINVAL.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
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>

4 files changed, 46 insertions, 29 deletions

diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index bb9948cdd50f..f1e5705e75f1 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -124,7 +124,7 @@ extern void ext2_check_inodes_bitmap (struct super_block *);
 extern unsigned long ext2_count_free (struct buffer_head *, unsigned);
 
 /* inode.c */
-extern void ext2_read_inode (struct inode *);
+extern struct inode *ext2_iget (struct super_block *, unsigned long);
 extern int ext2_write_inode (struct inode *, int);
 extern void ext2_put_inode (struct inode *);
 extern void ext2_delete_inode (struct inode *);
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 03978ec2a91c..c62006805427 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1181,22 +1181,33 @@ void ext2_get_inode_flags(struct ext2_inode_info *ei)
                 ei->i_flags |= EXT2_DIRSYNC_FL;
 }
 
-void ext2_read_inode (struct inode * inode)
+struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
 {
-        struct ext2_inode_info *ei = EXT2_I(inode);
-        ino_t ino = inode->i_ino;
+        struct ext2_inode_info *ei;
         struct buffer_head * bh;
-        struct ext2_inode * raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
+        struct ext2_inode *raw_inode;
+        struct inode *inode;
+        long ret = -EIO;
         int n;
 
+        inode = iget_locked(sb, ino);
+        if (!inode)
+                return ERR_PTR(-ENOMEM);
+        if (!(inode->i_state & I_NEW))
+                return inode;
+
+        ei = EXT2_I(inode);
 #ifdef CONFIG_EXT2_FS_POSIX_ACL
         ei->i_acl = EXT2_ACL_NOT_CACHED;
         ei->i_default_acl = EXT2_ACL_NOT_CACHED;
 #endif
         ei->i_block_alloc_info = NULL;
 
-        if (IS_ERR(raw_inode))
+        raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
+        if (IS_ERR(raw_inode)) {
+                ret = PTR_ERR(raw_inode);
                 goto bad_inode;
+        }
 
         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
         inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
@@ -1220,6 +1231,7 @@ void ext2_read_inode (struct inode * inode)
         if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) {
                 /* this inode is deleted */
                 brelse (bh);
+                ret = -ESTALE;
                 goto bad_inode;
         }
         inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
@@ -1286,11 +1298,12 @@ void ext2_read_inode (struct inode * inode)
         }
         brelse (bh);
         ext2_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 ext2_update_inode(struct inode * inode, int do_sync)
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index e69beed839ac..80c97fd8c571 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -63,9 +63,9 @@ static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, str
         ino = ext2_inode_by_name(dir, dentry);
         inode = NULL;
         if (ino) {
-                inode = iget(dir->i_sb, ino);
-                if (!inode)
-                        return ERR_PTR(-EACCES);
+                inode = ext2_iget(dir->i_sb, ino);
+                if (IS_ERR(inode))
+                        return ERR_CAST(inode);
         }
         return d_splice_alias(inode, dentry);
 }
@@ -83,10 +83,10 @@ struct dentry *ext2_get_parent(struct dentry *child)
         ino = ext2_inode_by_name(child->d_inode, &dotdot);
         if (!ino)
                 return ERR_PTR(-ENOENT);
-        inode = iget(child->d_inode->i_sb, ino);
+        inode = ext2_iget(child->d_inode->i_sb, ino);
 
-        if (!inode)
-                return ERR_PTR(-EACCES);
+        if (IS_ERR(inode))
+                return ERR_CAST(inode);
         parent = d_alloc_anon(inode);
         if (!parent) {
                 iput(inode);
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 1ba18b72d43a..22f1010bf79f 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -296,7 +296,6 @@ static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *da
 static const struct super_operations ext2_sops = {
         .alloc_inode    = ext2_alloc_inode,
         .destroy_inode  = ext2_destroy_inode,
-        .read_inode     = ext2_read_inode,
         .write_inode    = ext2_write_inode,
         .delete_inode   = ext2_delete_inode,
         .put_super      = ext2_put_super,
@@ -326,11 +325,10 @@ static struct inode *ext2_nfs_get_inode(struct super_block *sb,
          * it might be "neater" to call ext2_get_inode first and check
          * if the inode is valid.....
          */
-        inode = iget(sb, ino);
-        if (inode == NULL)
-                return ERR_PTR(-ENOMEM);
-        if (is_bad_inode(inode) ||
-            (generation && inode->i_generation != generation)) {
+        inode = ext2_iget(sb, ino);
+        if (IS_ERR(inode))
+                return ERR_CAST(inode);
+        if (generation && inode->i_generation != generation) {
                 /* we didn't find the right inode.. */
                 iput(inode);
                 return ERR_PTR(-ESTALE);
@@ -746,6 +744,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
         unsigned long logic_sb_block;
         unsigned long offset = 0;
         unsigned long def_mount_opts;
+        long ret = -EINVAL;
         int blocksize = BLOCK_SIZE;
         int db_count;
         int i, j;
@@ -1041,19 +1040,24 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
         sb->s_op = &ext2_sops;
         sb->s_export_op = &ext2_export_ops;
         sb->s_xattr = ext2_xattr_handlers;
-        root = iget(sb, EXT2_ROOT_INO);
-        sb->s_root = d_alloc_root(root);
-        if (!sb->s_root) {
-                iput(root);
-                printk(KERN_ERR "EXT2-fs: get root inode failed\n");
+        root = ext2_iget(sb, EXT2_ROOT_INO);
+        if (IS_ERR(root)) {
+                ret = PTR_ERR(root);
                 goto failed_mount3;
         }
         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
-                dput(sb->s_root);
-                sb->s_root = NULL;
+                iput(root);
                 printk(KERN_ERR "EXT2-fs: corrupt root inode, run e2fsck\n");
                 goto failed_mount3;
         }
+
+        sb->s_root = d_alloc_root(root);
+        if (!sb->s_root) {
+                iput(root);
+                printk(KERN_ERR "EXT2-fs: get root inode failed\n");
+                ret = -ENOMEM;
+                goto failed_mount3;
+        }
         if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
                 ext2_warning(sb, __FUNCTION__,
                         "mounting ext3 filesystem as ext2");
@@ -1080,7 +1084,7 @@ failed_mount:
 failed_sbi:
         sb->s_fs_info = NULL;
         kfree(sbi);
-        return -EINVAL;
+        return ret;
 }
 
 static void ext2_commit_super (struct super_block * sb,