btrfs: apply the AUTO_K(V)FREE macros throughout the code

Apply the AUTO_KFREE and AUTO_KVFREE macros wherever it makes
sense. Since this macro is expected to improve code readability, it has
been avoided in places where the lifetime of objects wasn't easy to
follow and a cleanup attribute would've made things worse; or when the
cleanup section of a function involved many other things and thus there
was no readability impact anyways. This change has also not been applied
in extremely short functions where readability was clearly not an issue.

Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: mssola

fs/btrfs/acl.c

@@ -14,12 +14,13 @@
 #include "ctree.h"
 #include "xattr.h"
 #include "acl.h"
+#include "misc.h"
 
 struct posix_acl *btrfs_get_acl(struct inode *inode, int type, bool rcu)
 {
 	int size;
 	const char *name;
-	char *value = NULL;
+	char AUTO_KFREE(value);
 	struct posix_acl *acl;
 
 	if (rcu)
@@ -49,7 +50,6 @@ struct posix_acl *btrfs_get_acl(struct inode *inode, int type, bool rcu)
 		acl = NULL;
 	else
 		acl = ERR_PTR(size);
-	kfree(value);
 
 	return acl;
 }
@@ -59,7 +59,7 @@ int __btrfs_set_acl(struct btrfs_trans_handle *trans, struct inode *inode,
 {
 	int ret, size = 0;
 	const char *name;
-	char *value = NULL;
+	char AUTO_KFREE(value);
 
 	switch (type) {
 	case ACL_TYPE_ACCESS:
@@ -85,28 +85,23 @@ int __btrfs_set_acl(struct btrfs_trans_handle *trans, struct inode *inode,
 		nofs_flag = memalloc_nofs_save();
 		value = kmalloc(size, GFP_KERNEL);
 		memalloc_nofs_restore(nofs_flag);
-		if (!value) {
-			ret = -ENOMEM;
-			goto out;
-		}
+		if (!value)
+			return -ENOMEM;
 
 		ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
 		if (ret < 0)
-			goto out;
+			return ret;
 	}
 
 	if (trans)
 		ret = btrfs_setxattr(trans, inode, name, value, size, 0);
 	else
 		ret = btrfs_setxattr_trans(inode, name, value, size, 0);
+	if (ret < 0)
+		return ret;
 
-out:
-	kfree(value);
-
-	if (!ret)
-		set_cached_acl(inode, type, acl);
-
-	return ret;
+	set_cached_acl(inode, type, acl);
+	return 0;
 }
 
 int btrfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,

fs/btrfs/delayed-inode.c

@@ -668,7 +668,7 @@ static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 	struct btrfs_key first_key;
 	const u32 first_data_size = first_item->data_len;
 	int total_size;
-	char *ins_data = NULL;
+	char AUTO_KFREE(ins_data);
 	int ret;
 	bool continuous_keys_only = false;
 
@@ -740,10 +740,8 @@ static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 
 		ins_data = kmalloc_array(batch.nr,
 					 sizeof(u32) + sizeof(struct btrfs_key), GFP_NOFS);
-		if (!ins_data) {
-			ret = -ENOMEM;
-			goto out;
-		}
+		if (!ins_data)
+			return -ENOMEM;
 		ins_sizes = (u32 *)ins_data;
 		ins_keys = (struct btrfs_key *)(ins_data + batch.nr * sizeof(u32));
 		batch.keys = ins_keys;
@@ -759,7 +757,7 @@ static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 
 	ret = btrfs_insert_empty_items(trans, root, path, &batch);
 	if (ret)
-		goto out;
+		return ret;
 
 	list_for_each_entry(curr, &item_list, tree_list) {
 		char *data_ptr;
@@ -814,9 +812,8 @@ static int btrfs_insert_delayed_item(struct btrfs_trans_handle *trans,
 		list_del(&curr->tree_list);
 		btrfs_release_delayed_item(curr);
 	}
-out:
-	kfree(ins_data);
-	return ret;
+
+	return 0;
 }
 
 static int btrfs_insert_delayed_items(struct btrfs_trans_handle *trans,

fs/btrfs/extent-tree.c

@@ -6058,7 +6058,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, bool update_ref, bool for_reloc
 	struct btrfs_trans_handle *trans;
 	struct btrfs_root *tree_root = fs_info->tree_root;
 	struct btrfs_root_item *root_item = &root->root_item;
-	struct walk_control *wc;
+	struct walk_control AUTO_KFREE(wc);
 	struct btrfs_key key;
 	const u64 rootid = btrfs_root_id(root);
 	int ret = 0;
@@ -6076,9 +6076,8 @@ int btrfs_drop_snapshot(struct btrfs_root *root, bool update_ref, bool for_reloc
 
 	wc = kzalloc(sizeof(*wc), GFP_NOFS);
 	if (!wc) {
-		btrfs_free_path(path);
 		ret = -ENOMEM;
-		goto out;
+		goto out_free;
 	}
 
 	/*
@@ -6288,7 +6287,6 @@ int btrfs_drop_snapshot(struct btrfs_root *root, bool update_ref, bool for_reloc
 
 	btrfs_end_transaction_throttle(trans);
 out_free:
-	kfree(wc);
 	btrfs_free_path(path);
 out:
 	if (!ret && root_dropped) {
@@ -6331,7 +6329,7 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	BTRFS_PATH_AUTO_FREE(path);
-	struct walk_control *wc;
+	struct walk_control AUTO_KFREE(wc);
 	int level;
 	int parent_level;
 	int ret = 0;
@@ -6370,18 +6368,17 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 	while (1) {
 		ret = walk_down_tree(trans, root, path, wc);
 		if (ret < 0)
-			break;
+			return ret;
 
 		ret = walk_up_tree(trans, root, path, wc, parent_level);
 		if (ret) {
-			if (ret > 0)
-				ret = 0;
+			if (ret < 0)
+				return ret;
 			break;
 		}
 	}
 
-	kfree(wc);
-	return ret;
+	return 0;
 }
 
 /*

fs/btrfs/ioctl.c

@@ -503,7 +503,7 @@ static noinline int create_subvol(struct mnt_idmap *idmap,
 	struct btrfs_fs_info *fs_info = inode_to_fs_info(dir);
 	struct btrfs_trans_handle *trans;
 	struct btrfs_key key;
-	struct btrfs_root_item *root_item;
+	struct btrfs_root_item AUTO_KFREE(root_item);
 	struct btrfs_inode_item *inode_item;
 	struct extent_buffer *leaf;
 	struct btrfs_root *root = BTRFS_I(dir)->root;
@@ -527,20 +527,18 @@ static noinline int create_subvol(struct mnt_idmap *idmap,
 
 	ret = btrfs_get_free_objectid(fs_info->tree_root, &objectid);
 	if (ret)
-		goto out_root_item;
+		return ret;
 
 	/*
 	 * Don't create subvolume whose level is not zero. Or qgroup will be
 	 * screwed up since it assumes subvolume qgroup's level to be 0.
 	 */
-	if (btrfs_qgroup_level(objectid)) {
-		ret = -ENOSPC;
-		goto out_root_item;
-	}
+	if (btrfs_qgroup_level(objectid))
+		return -ENOSPC;
 
 	ret = get_anon_bdev(&anon_dev);
 	if (ret < 0)
-		goto out_root_item;
+		return ret;
 
 	new_inode_args.inode = btrfs_new_subvol_inode(idmap, dir);
 	if (!new_inode_args.inode) {
@@ -692,8 +690,7 @@ static noinline int create_subvol(struct mnt_idmap *idmap,
 out_anon_dev:
 	if (anon_dev)
 		free_anon_bdev(anon_dev);
-out_root_item:
-	kfree(root_item);
+
 	return ret;
 }
 
@@ -2956,7 +2953,7 @@ static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
 	struct btrfs_ioctl_space_args space_args = { 0 };
 	struct btrfs_ioctl_space_info space;
 	struct btrfs_ioctl_space_info *dest;
-	struct btrfs_ioctl_space_info *dest_orig;
+	struct btrfs_ioctl_space_info AUTO_KFREE(dest_orig);
 	struct btrfs_ioctl_space_info __user *user_dest;
 	struct btrfs_space_info *info;
 	static const u64 types[] = {
@@ -3077,9 +3074,8 @@ static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
 		(arg + sizeof(struct btrfs_ioctl_space_args));
 
 	if (copy_to_user(user_dest, dest_orig, alloc_size))
-		ret = -EFAULT;
+		return -EFAULT;
 
-	kfree(dest_orig);
 out:
 	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
 		ret = -EFAULT;
@@ -3610,7 +3606,7 @@ static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
 					 void __user *arg)
 {
-	struct btrfs_ioctl_balance_args *bargs;
+	struct btrfs_ioctl_balance_args AUTO_KFREE(bargs);
 	int ret = 0;
 
 	if (!capable(CAP_SYS_ADMIN))
@@ -3632,8 +3628,6 @@ static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
 
 	if (copy_to_user(arg, bargs, sizeof(*bargs)))
 		ret = -EFAULT;
-
-	kfree(bargs);
 out:
 	mutex_unlock(&fs_info->balance_mutex);
 	return ret;
@@ -4227,20 +4221,19 @@ static int check_feature_bits(const struct btrfs_fs_info *fs_info,
 			      u64 safe_set, u64 safe_clear)
 {
 	const char *type = btrfs_feature_set_name(set);
-	char *names;
+	const char AUTO_KFREE(names);
 	u64 disallowed, unsupported;
 	u64 set_mask = flags & change_mask;
 	u64 clear_mask = ~flags & change_mask;
 
 	unsupported = set_mask & ~supported_flags;
 	if (unsupported) {
 		names = btrfs_printable_features(set, unsupported);
-		if (names) {
+		if (names)
 			btrfs_warn(fs_info,
 				   "this kernel does not support the %s feature bit%s",
 				   names, strchr(names, ',') ? "s" : "");
-			kfree(names);
-		} else
+		else
 			btrfs_warn(fs_info,
 				   "this kernel does not support %s bits 0x%llx",
 				   type, unsupported);
@@ -4250,12 +4243,11 @@ static int check_feature_bits(const struct btrfs_fs_info *fs_info,
 	disallowed = set_mask & ~safe_set;
 	if (disallowed) {
 		names = btrfs_printable_features(set, disallowed);
-		if (names) {
+		if (names)
 			btrfs_warn(fs_info,
 				   "can't set the %s feature bit%s while mounted",
 				   names, strchr(names, ',') ? "s" : "");
-			kfree(names);
-		} else
+		else
 			btrfs_warn(fs_info,
 				   "can't set %s bits 0x%llx while mounted",
 				   type, disallowed);
@@ -4265,12 +4257,11 @@ static int check_feature_bits(const struct btrfs_fs_info *fs_info,
 	disallowed = clear_mask & ~safe_clear;
 	if (disallowed) {
 		names = btrfs_printable_features(set, disallowed);
-		if (names) {
+		if (names)
 			btrfs_warn(fs_info,
 				   "can't clear the %s feature bit%s while mounted",
 				   names, strchr(names, ',') ? "s" : "");
-			kfree(names);
-		} else
+		else
 			btrfs_warn(fs_info,
 				   "can't clear %s bits 0x%llx while mounted",
 				   type, disallowed);

fs/btrfs/qgroup.c

@@ -4794,7 +4794,7 @@ int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_tree_parent_check check = { 0 };
 	struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks;
-	struct btrfs_qgroup_swapped_block *block;
+	struct btrfs_qgroup_swapped_block AUTO_KFREE(block);
 	struct extent_buffer *reloc_eb = NULL;
 	struct rb_node *node;
 	bool swapped = false;
@@ -4851,7 +4851,6 @@ int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
 	ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb,
 			block->last_snapshot, block->trace_leaf);
 free_out:
-	kfree(block);
 	free_extent_buffer(reloc_eb);
 out:
 	if (ret < 0) {

fs/btrfs/raid-stripe-tree.c

@@ -19,7 +19,7 @@ static int btrfs_partially_delete_raid_extent(struct btrfs_trans_handle *trans,
 					       u64 newlen, u64 frontpad)
 {
 	struct btrfs_root *stripe_root = trans->fs_info->stripe_root;
-	struct btrfs_stripe_extent *extent, *newitem;
+	struct btrfs_stripe_extent *extent, AUTO_KFREE(newitem);
 	struct extent_buffer *leaf;
 	int slot;
 	size_t item_size;
@@ -53,14 +53,10 @@ static int btrfs_partially_delete_raid_extent(struct btrfs_trans_handle *trans,
 
 	ret = btrfs_del_item(trans, stripe_root, path);
 	if (ret)
-		goto out;
+		return ret;
 
 	btrfs_release_path(path);
-	ret = btrfs_insert_item(trans, stripe_root, &newkey, newitem, item_size);
-
-out:
-	kfree(newitem);
-	return ret;
+	return btrfs_insert_item(trans, stripe_root, &newkey, newitem, item_size);
 }
 
 int btrfs_delete_raid_extent(struct btrfs_trans_handle *trans, u64 start, u64 length)
@@ -299,7 +295,7 @@ int btrfs_insert_one_raid_extent(struct btrfs_trans_handle *trans,
 	struct btrfs_key stripe_key;
 	struct btrfs_root *stripe_root = fs_info->stripe_root;
 	const int num_stripes = btrfs_bg_type_to_factor(bioc->map_type);
-	struct btrfs_stripe_extent *stripe_extent;
+	struct btrfs_stripe_extent AUTO_KFREE(stripe_extent);
 	const size_t item_size = struct_size(stripe_extent, strides, num_stripes);
 	int ret;
 
@@ -336,8 +332,6 @@ int btrfs_insert_one_raid_extent(struct btrfs_trans_handle *trans,
 		btrfs_abort_transaction(trans, ret);
 	}
 
-	kfree(stripe_extent);
-
 	return ret;
 }
 

fs/btrfs/reflink.c

@@ -343,7 +343,7 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
 	BTRFS_PATH_AUTO_FREE(path);
 	struct extent_buffer *leaf;
 	struct btrfs_trans_handle *trans;
-	char *buf = NULL;
+	char AUTO_KVFREE(buf);
 	struct btrfs_key key;
 	u32 nritems;
 	int slot;
@@ -358,10 +358,8 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
 		return ret;
 
 	path = btrfs_alloc_path();
-	if (!path) {
-		kvfree(buf);
+	if (!path)
 		return ret;
-	}
 
 	path->reada = READA_FORWARD;
 	/* Clone data */
@@ -611,7 +609,6 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
 	}
 
 out:
-	kvfree(buf);
 	clear_bit(BTRFS_INODE_NO_DELALLOC_FLUSH, &BTRFS_I(inode)->runtime_flags);
 
 	return ret;