[PATCH] switch all filesystems over to d_obtain_alias

Switch all users of d_alloc_anon to d_obtain_alias.

Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Al Viro <[email protected]>

fs/dcache.c

@@ -1187,17 +1187,17 @@ struct dentry * d_alloc_anon(struct inode *inode)
  * allocating a new one.
  *
  * On successful return, the reference to the inode has been transferred
- * to the dentry.  If %NULL is returned (indicating kmalloc failure),
- * the reference on the inode has been released.  To make it easier
- * to use in export operations a NULL or IS_ERR inode may be passed in
- * and will be casted to the corresponding NULL or IS_ERR dentry.
+ * to the dentry.  In case of an error the reference on the inode is released.
+ * To make it easier to use in export operations a %NULL or IS_ERR inode may
+ * be passed in and will be the error will be propagate to the return value,
+ * with a %NULL @inode replaced by ERR_PTR(-ESTALE).
  */
 struct dentry *d_obtain_alias(struct inode *inode)
 {
 	struct dentry *dentry;
 
 	if (!inode)
-		return NULL;
+		return ERR_PTR(-ESTALE);
 	if (IS_ERR(inode))
 		return ERR_CAST(inode);
 

fs/efs/namei.c

@@ -112,35 +112,14 @@ struct dentry *efs_fh_to_parent(struct super_block *sb, struct fid *fid,
 
 struct dentry *efs_get_parent(struct dentry *child)
 {
-	struct dentry *parent;
-	struct inode *inode;
+	struct dentry *parent = ERR_PTR(-ENOENT);
 	efs_ino_t ino;
-	long error;
 
 	lock_kernel();
-
-	error = -ENOENT;
 	ino = efs_find_entry(child->d_inode, "..", 2);
-	if (!ino)
-		goto fail;
-
-	inode = efs_iget(child->d_inode->i_sb, ino);
-	if (IS_ERR(inode)) {
-		error = PTR_ERR(inode);
-		goto fail;
-	}
-
-	error = -ENOMEM;
-	parent = d_alloc_anon(inode);
-	if (!parent)
-		goto fail_iput;
-
+	if (ino)
+		parent = d_obtain_alias(efs_iget(child->d_inode->i_sb, ino));
 	unlock_kernel();
-	return parent;
 
- fail_iput:
-	iput(inode);
- fail:
-	unlock_kernel();
-	return ERR_PTR(error);
+	return parent;
 }

fs/exportfs/expfs.c

@@ -366,8 +366,6 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
 	 * Try to get any dentry for the given file handle from the filesystem.
 	 */
 	result = nop->fh_to_dentry(mnt->mnt_sb, fid, fh_len, fileid_type);
-	if (!result)
-		result = ERR_PTR(-ESTALE);
 	if (IS_ERR(result))
 		return result;
 
@@ -422,8 +420,6 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
 
 		target_dir = nop->fh_to_parent(mnt->mnt_sb, fid,
 				fh_len, fileid_type);
-		if (!target_dir)
-			goto err_result;
 		err = PTR_ERR(target_dir);
 		if (IS_ERR(target_dir))
 			goto err_result;

fs/ext2/namei.c

@@ -73,8 +73,6 @@ static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, str
 struct dentry *ext2_get_parent(struct dentry *child)
 {
 	unsigned long ino;
-	struct dentry *parent;
-	struct inode *inode;
 	struct dentry dotdot;
 
 	dotdot.d_name.name = "..";
@@ -83,16 +81,7 @@ struct dentry *ext2_get_parent(struct dentry *child)
 	ino = ext2_inode_by_name(child->d_inode, &dotdot);
 	if (!ino)
 		return ERR_PTR(-ENOENT);
-	inode = ext2_iget(child->d_inode->i_sb, ino);
-
-	if (IS_ERR(inode))
-		return ERR_CAST(inode);
-	parent = d_alloc_anon(inode);
-	if (!parent) {
-		iput(inode);
-		parent = ERR_PTR(-ENOMEM);
-	}
-	return parent;
+	return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino));
 } 
 
 /*

fs/ext3/namei.c

@@ -1057,8 +1057,6 @@ static struct dentry *ext3_lookup(struct inode * dir, struct dentry *dentry, str
 struct dentry *ext3_get_parent(struct dentry *child)
 {
 	unsigned long ino;
-	struct dentry *parent;
-	struct inode *inode;
 	struct dentry dotdot;
 	struct ext3_dir_entry_2 * de;
 	struct buffer_head *bh;
@@ -1068,7 +1066,6 @@ struct dentry *ext3_get_parent(struct dentry *child)
 	dotdot.d_parent = child; /* confusing, isn't it! */
 
 	bh = ext3_find_entry(&dotdot, &de);
-	inode = NULL;
 	if (!bh)
 		return ERR_PTR(-ENOENT);
 	ino = le32_to_cpu(de->inode);
@@ -1080,16 +1077,7 @@ struct dentry *ext3_get_parent(struct dentry *child)
 		return ERR_PTR(-EIO);
 	}
 
-	inode = ext3_iget(child->d_inode->i_sb, ino);
-	if (IS_ERR(inode))
-		return ERR_CAST(inode);
-
-	parent = d_alloc_anon(inode);
-	if (!parent) {
-		iput(inode);
-		parent = ERR_PTR(-ENOMEM);
-	}
-	return parent;
+	return d_obtain_alias(ext3_iget(child->d_inode->i_sb, ino));
 }
 
 #define S_SHIFT 12

fs/ext4/namei.c

@@ -1083,16 +1083,7 @@ struct dentry *ext4_get_parent(struct dentry *child)
 		return ERR_PTR(-EIO);
 	}
 
-	inode = ext4_iget(child->d_inode->i_sb, ino);
-	if (IS_ERR(inode))
-		return ERR_CAST(inode);
-
-	parent = d_alloc_anon(inode);
-	if (!parent) {
-		iput(inode);
-		parent = ERR_PTR(-ENOMEM);
-	}
-	return parent;
+	return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
 }
 
 #define S_SHIFT 12

fs/fat/inode.c

@@ -681,33 +681,24 @@ static struct dentry *fat_fh_to_dentry(struct super_block *sb,
 			inode = NULL;
 		}
 	}
-	if (!inode) {
-		/* For now, do nothing
-		 * What we could do is:
-		 * follow the file starting at fh[4], and record
-		 * the ".." entry, and the name of the fh[2] entry.
-		 * The follow the ".." file finding the next step up.
-		 * This way we build a path to the root of
-		 * the tree. If this works, we lookup the path and so
-		 * get this inode into the cache.
-		 * Finally try the fat_iget lookup again
-		 * If that fails, then weare totally out of luck
-		 * But all that is for another day
-		 */
-	}
-	if (!inode)
-		return ERR_PTR(-ESTALE);
-
 
-	/* now to find a dentry.
-	 * If possible, get a well-connected one
+	/*
+	 * For now, do nothing if the inode is not found.
+	 *
+	 * What we could do is:
+	 *
+	 *	- follow the file starting at fh[4], and record the ".." entry,
+	 *	  and the name of the fh[2] entry.
+	 *	- then follow the ".." file finding the next step up.
+	 *
+	 * This way we build a path to the root of the tree. If this works, we
+	 * lookup the path and so get this inode into the cache.  Finally try
+	 * the fat_iget lookup again.  If that fails, then we are totally out
+	 * of luck.  But all that is for another day
 	 */
-	result = d_alloc_anon(inode);
-	if (result == NULL) {
-		iput(inode);
-		return ERR_PTR(-ENOMEM);
-	}
-	result->d_op = sb->s_root->d_op;
+	result = d_obtain_alias(inode);
+	if (!IS_ERR(result))
+		result->d_op = sb->s_root->d_op;
 	return result;
 }
 
@@ -754,15 +745,8 @@ static struct dentry *fat_get_parent(struct dentry *child)
 	}
 	inode = fat_build_inode(sb, de, i_pos);
 	brelse(bh);
-	if (IS_ERR(inode)) {
-		parent = ERR_CAST(inode);
-		goto out;
-	}
-	parent = d_alloc_anon(inode);
-	if (!parent) {
-		iput(inode);
-		parent = ERR_PTR(-ENOMEM);
-	}
+
+	parent = d_obtain_alias(inode);
 out:
 	unlock_super(sb);
 

fs/fuse/inode.c

@@ -596,12 +596,8 @@ static struct dentry *fuse_get_dentry(struct super_block *sb,
 	if (inode->i_generation != handle->generation)
 		goto out_iput;
 
-	entry = d_alloc_anon(inode);
-	err = -ENOMEM;
-	if (!entry)
-		goto out_iput;
-
-	if (get_node_id(inode) != FUSE_ROOT_ID) {
+	entry = d_obtain_alias(inode);
+	if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) {
 		entry->d_op = &fuse_dentry_operations;
 		fuse_invalidate_entry_cache(entry);
 	}
@@ -696,17 +692,14 @@ static struct dentry *fuse_get_parent(struct dentry *child)
 	name.name = "..";
 	err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
 			       &name, &outarg, &inode);
-	if (err && err != -ENOENT)
+	if (err) {
+		if (err == -ENOENT)
+			return ERR_PTR(-ESTALE);
 		return ERR_PTR(err);
-	if (err || !inode)
-		return ERR_PTR(-ESTALE);
-
-	parent = d_alloc_anon(inode);
-	if (!parent) {
-		iput(inode);
-		return ERR_PTR(-ENOMEM);
 	}
-	if (get_node_id(inode) != FUSE_ROOT_ID) {
+
+	parent = d_obtain_alias(inode);
+	if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) {
 		parent->d_op = &fuse_dentry_operations;
 		fuse_invalidate_entry_cache(parent);
 	}

fs/gfs2/ops_export.c

@@ -130,28 +130,17 @@ static int gfs2_get_name(struct dentry *parent, char *name,
 static struct dentry *gfs2_get_parent(struct dentry *child)
 {
 	struct qstr dotdot;
-	struct inode *inode;
 	struct dentry *dentry;
 
-	gfs2_str2qstr(&dotdot, "..");
-	inode = gfs2_lookupi(child->d_inode, &dotdot, 1);
-
-	if (!inode)
-		return ERR_PTR(-ENOENT);
 	/*
-	 * In case of an error, @inode carries the error value, and we
-	 * have to return that as a(n invalid) pointer to dentry.
+	 * XXX(hch): it would be a good idea to keep this around as a
+	 *	     static variable.
 	 */
-	if (IS_ERR(inode))
-		return ERR_CAST(inode);
-
-	dentry = d_alloc_anon(inode);
-	if (!dentry) {
-		iput(inode);
-		return ERR_PTR(-ENOMEM);
-	}
+	gfs2_str2qstr(&dotdot, "..");
 
-	dentry->d_op = &gfs2_dops;
+	dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &dotdot, 1));
+	if (!IS_ERR(dentry))
+		dentry->d_op = &gfs2_dops;
 	return dentry;
 }
 
@@ -233,13 +222,9 @@ static struct dentry *gfs2_get_dentry(struct super_block *sb,
 	gfs2_glock_dq_uninit(&i_gh);
 
 out_inode:
-	dentry = d_alloc_anon(inode);
-	if (!dentry) {
-		iput(inode);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	dentry->d_op = &gfs2_dops;
+	dentry = d_obtain_alias(inode);
+	if (!IS_ERR(dentry))
+		dentry->d_op = &gfs2_dops;
 	return dentry;
 
 fail_rgd:

fs/isofs/export.c

@@ -22,7 +22,7 @@ isofs_export_iget(struct super_block *sb,
 		  __u32 generation)
 {
 	struct inode *inode;
-	struct dentry *result;
+
 	if (block == 0)
 		return ERR_PTR(-ESTALE);
 	inode = isofs_iget(sb, block, offset);
@@ -32,12 +32,7 @@ isofs_export_iget(struct super_block *sb,
 		iput(inode);
 		return ERR_PTR(-ESTALE);
 	}
-	result = d_alloc_anon(inode);
-	if (!result) {
-		iput(inode);
-		return ERR_PTR(-ENOMEM);
-	}
-	return result;
+	return d_obtain_alias(inode);
 }
 
 /* This function is surprisingly simple.  The trick is understanding
@@ -51,7 +46,6 @@ static struct dentry *isofs_export_get_parent(struct dentry *child)
 	unsigned long parent_offset = 0;
 	struct inode *child_inode = child->d_inode;
 	struct iso_inode_info *e_child_inode = ISOFS_I(child_inode);
-	struct inode *parent_inode = NULL;
 	struct iso_directory_record *de = NULL;
 	struct buffer_head * bh = NULL;
 	struct dentry *rv = NULL;
@@ -104,28 +98,11 @@ static struct dentry *isofs_export_get_parent(struct dentry *child)
 	/* Normalize */
 	isofs_normalize_block_and_offset(de, &parent_block, &parent_offset);
 
-	/* Get the inode. */
-	parent_inode = isofs_iget(child_inode->i_sb,
-				  parent_block,
-				  parent_offset);
-	if (IS_ERR(parent_inode)) {
-		rv = ERR_CAST(parent_inode);
-		if (rv != ERR_PTR(-ENOMEM))
-			rv = ERR_PTR(-EACCES);
-		goto out;
-	}
-
-	/* Allocate the dentry. */
-	rv = d_alloc_anon(parent_inode);
-	if (rv == NULL) {
-		rv = ERR_PTR(-ENOMEM);
-		goto out;
-	}
-
+	rv = d_obtain_alias(isofs_iget(child_inode->i_sb, parent_block,
+				     parent_offset));
  out:
-	if (bh) {
+	if (bh)
 		brelse(bh);
-	}
 	return rv;
 }