From 448999d84ddc2eaf36938176fb5091d2c2029e2f Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Mon, 28 Aug 2017 16:48:16 +0200
Subject: btrfs-progs: add crude error handling when transaction start fails

Currently transaction bugs out insided btrfs_start_transaction in case
of error, we want to lift the error handling to the callers. This patch
adds the BUG_ON anywhere it's been missing so far. This is not the best
way of course. Transforming BUG_ON to a proper error handling highly
depends on the caller and should be dealt with case by case.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 btrfs-corrupt-block.c     |  7 +++++++
 btrfs-zero-log.c          |  1 +
 btrfstune.c               |  2 ++
 chunk-recover.c           |  1 +
 cmds-rescue.c             |  1 +
 convert/main.c            | 10 +++++-----
 convert/source-ext2.c     |  6 +++---
 convert/source-reiserfs.c | 24 ++++++++++++------------
 dir-test.c                |  1 +
 disk-io.c                 |  2 ++
 mkfs/main.c               |  8 ++++++--
 quick-test.c              |  5 +++++
 random-test.c             |  1 +
 utils.c                   |  1 +
 14 files changed, 48 insertions(+), 22 deletions(-)

diff --git a/btrfs-corrupt-block.c b/btrfs-corrupt-block.c
index 83adcf80..59ee1b45 100644
--- a/btrfs-corrupt-block.c
+++ b/btrfs-corrupt-block.c
@@ -1226,13 +1226,16 @@ int main(int argc, char **argv)
 		if (logical == (u64)-1)
 			print_usage(1);
 		trans = btrfs_start_transaction(root, 1);
+		BUG_ON(IS_ERR(trans));
 		ret = corrupt_extent(trans, root, logical);
 		btrfs_commit_transaction(trans, root);
 		goto out_close;
 	}
 	if (extent_tree) {
 		struct btrfs_trans_handle *trans;
+
 		trans = btrfs_start_transaction(root, 1);
+		BUG_ON(IS_ERR(trans));
 		btrfs_corrupt_extent_tree(trans, root->fs_info->extent_root,
 					  root->fs_info->extent_root->node);
 		btrfs_commit_transaction(trans, root);
@@ -1258,6 +1261,7 @@ int main(int argc, char **argv)
 			goto out_close;
 		}
 		trans = btrfs_start_transaction(root, 1);
+		BUG_ON(IS_ERR(trans));
 		ret = corrupt_item_nocow(trans, root->fs_info->chunk_root,
 					 path, del);
 		if (ret < 0)
@@ -1267,7 +1271,9 @@ int main(int argc, char **argv)
 	}
 	if (chunk_tree) {
 		struct btrfs_trans_handle *trans;
+
 		trans = btrfs_start_transaction(root, 1);
+		BUG_ON(IS_ERR(trans));
 		ret = corrupt_chunk_tree(trans, root->fs_info->chunk_root);
 		if (ret < 0)
 			fprintf(stderr, "Failed to corrupt chunk tree\n");
@@ -1281,6 +1287,7 @@ int main(int argc, char **argv)
 			print_usage(1);
 
 		trans = btrfs_start_transaction(root, 1);
+		BUG_ON(IS_ERR(trans));
 		if (file_extent == (u64)-1) {
 			printf("corrupting inode\n");
 			ret = corrupt_inode(trans, root, inode, field);
diff --git a/btrfs-zero-log.c b/btrfs-zero-log.c
index 697026aa..2fce59e9 100644
--- a/btrfs-zero-log.c
+++ b/btrfs-zero-log.c
@@ -68,6 +68,7 @@ int main(int argc, char **argv)
 			(unsigned long long)btrfs_super_log_root(sb),
 			(unsigned)btrfs_super_log_root_level(sb));
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	btrfs_set_super_log_root(root->fs_info->super_copy, 0);
 	btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
 	btrfs_commit_transaction(trans, root);
diff --git a/btrfstune.c b/btrfstune.c
index 0139e408..eccedf79 100644
--- a/btrfstune.c
+++ b/btrfstune.c
@@ -66,6 +66,7 @@ static int update_seeding_flag(struct btrfs_root *root, int set_flag)
 	}
 
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	btrfs_set_super_flags(disk_super, super_flags);
 	ret = btrfs_commit_transaction(trans, root);
 
@@ -83,6 +84,7 @@ static int set_super_incompat_flags(struct btrfs_root *root, u64 flags)
 	super_flags = btrfs_super_incompat_flags(disk_super);
 	super_flags |= flags;
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	btrfs_set_super_incompat_flags(disk_super, super_flags);
 	ret = btrfs_commit_transaction(trans, root);
 
diff --git a/chunk-recover.c b/chunk-recover.c
index f1fa7504..4a6d7141 100644
--- a/chunk-recover.c
+++ b/chunk-recover.c
@@ -2389,6 +2389,7 @@ int btrfs_recover_chunk_tree(char *path, int verbose, int yes)
 	}
 
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	ret = remove_chunk_extent_item(trans, &rc, root);
 	BUG_ON(ret);
 
diff --git a/cmds-rescue.c b/cmds-rescue.c
index 7e7344ee..d1bec021 100644
--- a/cmds-rescue.c
+++ b/cmds-rescue.c
@@ -191,6 +191,7 @@ static int cmd_rescue_zero_log(int argc, char **argv)
 			(unsigned long long)btrfs_super_log_root(sb),
 			(unsigned)btrfs_super_log_root_level(sb));
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	btrfs_set_super_log_root(sb, 0);
 	btrfs_set_super_log_root_level(sb, 0);
 	btrfs_commit_transaction(trans, root);
diff --git a/convert/main.c b/convert/main.c
index 22884bd5..7ec6202d 100644
--- a/convert/main.c
+++ b/convert/main.c
@@ -751,8 +751,8 @@ static int create_image(struct btrfs_root *root,
 		flags |= BTRFS_INODE_NODATASUM;
 
 	trans = btrfs_start_transaction(root, 1);
-	if (!trans)
-		return -ENOMEM;
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
 
 	cache_tree_init(&used_tmp);
 	btrfs_init_path(&path);
@@ -881,7 +881,7 @@ static struct btrfs_root* link_subvol(struct btrfs_root *root,
 	btrfs_release_path(&path);
 
 	trans = btrfs_start_transaction(root, 1);
-	if (!trans) {
+	if (IS_ERR(trans)) {
 		error("unable to start transaction");
 		goto fail;
 	}
@@ -1077,9 +1077,9 @@ static int init_btrfs(struct btrfs_mkfs_config *cfg, struct btrfs_root *root,
 	fs_info->avoid_sys_chunk_alloc = 1;
 	fs_info->avoid_meta_chunk_alloc = 1;
 	trans = btrfs_start_transaction(root, 1);
-	if (!trans) {
+	if (IS_ERR(trans)) {
 		error("unable to start transaction");
-		ret = -EINVAL;
+		ret = PTR_ERR(trans);
 		goto err;
 	}
 	ret = btrfs_fix_block_accounting(trans, root);
diff --git a/convert/source-ext2.c b/convert/source-ext2.c
index f1075da5..559669ff 100644
--- a/convert/source-ext2.c
+++ b/convert/source-ext2.c
@@ -803,8 +803,8 @@ static int ext2_copy_inodes(struct btrfs_convert_context *cctx,
 	struct btrfs_trans_handle *trans;
 
 	trans = btrfs_start_transaction(root, 1);
-	if (!trans)
-		return -ENOMEM;
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
 	err = ext2fs_open_inode_scan(ext2_fs, 0, &ext2_scan);
 	if (err) {
 		fprintf(stderr, "ext2fs_open_inode_scan: %s\n", error_message(err));
@@ -830,7 +830,7 @@ static int ext2_copy_inodes(struct btrfs_convert_context *cctx,
 			ret = btrfs_commit_transaction(trans, root);
 			BUG_ON(ret);
 			trans = btrfs_start_transaction(root, 1);
-			BUG_ON(!trans);
+			BUG_ON(IS_ERR(trans));
 		}
 	}
 	if (err) {
diff --git a/convert/source-reiserfs.c b/convert/source-reiserfs.c
index d6389bf9..be79d8e2 100644
--- a/convert/source-reiserfs.c
+++ b/convert/source-reiserfs.c
@@ -500,8 +500,8 @@ static int reiserfs_copy_dirent(reiserfs_filsys_t fs,
 		return ret;
 	}
 	trans = btrfs_start_transaction(root, 1);
-	if (!trans)
-		return -ENOMEM;
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
 
 	ret = convert_insert_dirent(trans, root, name, len, dir_objectid,
 				    objectid, type, dirent_data->index++,
@@ -613,8 +613,8 @@ static int reiserfs_copy_meta(reiserfs_filsys_t fs, struct btrfs_root *root,
 	switch (mode & S_IFMT) {
 	case S_IFREG:
 		trans = btrfs_start_transaction(root, 1);
-		if (!trans) {
-			ret = -ENOMEM;
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
 			goto fail;
 		}
 		ret = reiserfs_record_file_extents(fs, trans, root, objectid,
@@ -629,8 +629,8 @@ static int reiserfs_copy_meta(reiserfs_filsys_t fs, struct btrfs_root *root,
 		if (ret)
 			goto fail;
 		trans = btrfs_start_transaction(root, 1);
-		if (!trans) {
-			ret = -ENOMEM;
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
 			goto fail;
 		}
 
@@ -639,8 +639,8 @@ static int reiserfs_copy_meta(reiserfs_filsys_t fs, struct btrfs_root *root,
 		break;
 	case S_IFLNK:
 		trans = btrfs_start_transaction(root, 1);
-		if (!trans) {
-			ret = -ENOMEM;
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
 			goto fail;
 		}
 		ret = reiserfs_copy_symlink(trans, root, objectid,
@@ -650,8 +650,8 @@ static int reiserfs_copy_meta(reiserfs_filsys_t fs, struct btrfs_root *root,
 		break;
 	default:
 		trans = btrfs_start_transaction(root, 1);
-		if (!trans) {
-			ret = -ENOMEM;
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
 			goto fail;
 		}
 	}
@@ -872,8 +872,8 @@ static int reiserfs_copy_xattr_dir(reiserfs_filsys_t fs,
 	xa_data->target_oid += OID_OFFSET;
 
 	xa_data->trans = btrfs_start_transaction(xa_data->root, 1);
-	if (!xa_data->trans)
-		return -ENOMEM;
+	if (IS_ERR(xa_data->trans))
+		return PTR_ERR(xa_data->trans);
 
 	ret = reiserfs_iterate_dir(fs, &dir_key,
 				    reiserfs_copy_one_xattr, xa_data);
diff --git a/dir-test.c b/dir-test.c
index 24f2c2e3..cfb77f2a 100644
--- a/dir-test.c
+++ b/dir-test.c
@@ -443,6 +443,7 @@ int main(int ac, char **av)
 	}
 
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 
 	dir_oid = btrfs_super_root_dir(&super);
 
diff --git a/disk-io.c b/disk-io.c
index 30e656c2..f969c9b5 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -1753,8 +1753,10 @@ int close_ctree_fs_info(struct btrfs_fs_info *fs_info)
 	    fs_info->generation) {
 		BUG_ON(!root);
 		trans = btrfs_start_transaction(root, 1);
+		BUG_ON(IS_ERR(trans));
 		btrfs_commit_transaction(trans, root);
 		trans = btrfs_start_transaction(root, 1);
+		BUG_ON(IS_ERR(trans));
 		ret = commit_tree_roots(trans, fs_info);
 		BUG_ON(ret);
 		ret = __commit_transaction(trans, root);
diff --git a/mkfs/main.c b/mkfs/main.c
index dfa7a031..f4952581 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -75,6 +75,7 @@ static int create_metadata_block_groups(struct btrfs_root *root, int mixed,
 	int ret;
 
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	bytes_used = btrfs_super_bytes_used(fs_info->super_copy);
 
 	root->fs_info->system_allocs = 1;
@@ -1047,6 +1048,7 @@ static int make_image(const char *source_dir, struct btrfs_root *root)
 	INIT_LIST_HEAD(&dir_head.list);
 
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	ret = traverse_directory(trans, root, source_dir, &dir_head);
 	if (ret) {
 		error("unable to traverse directory %s: %d", source_dir, ret);
@@ -1325,6 +1327,7 @@ static int cleanup_temp_chunks(struct btrfs_fs_info *fs_info,
 
 	btrfs_init_path(&path);
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 
 	key.objectid = 0;
 	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
@@ -1758,7 +1761,7 @@ int main(int argc, char **argv)
 	}
 
 	trans = btrfs_start_transaction(root, 1);
-	if (!trans) {
+	if (IS_ERR(trans)) {
 		error("failed to start transaction");
 		goto error;
 	}
@@ -1782,7 +1785,7 @@ int main(int argc, char **argv)
 	}
 
 	trans = btrfs_start_transaction(root, 1);
-	if (!trans) {
+	if (IS_ERR(trans)) {
 		error("failed to start transaction");
 		goto error;
 	}
@@ -1860,6 +1863,7 @@ raid_groups:
 
 	if (source_dir_set) {
 		trans = btrfs_start_transaction(root, 1);
+		BUG_ON(IS_ERR(trans));
 		ret = create_chunks(trans, root,
 				    num_of_meta_chunks, size_of_data,
 				    &allocation);
diff --git a/quick-test.c b/quick-test.c
index f99ecc38..b1e7999d 100644
--- a/quick-test.c
+++ b/quick-test.c
@@ -56,6 +56,7 @@ int main(int ac, char **av) {
 		exit(1);
 	}
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	srand(55);
 	ins.type = BTRFS_STRING_ITEM_KEY;
 	for (i = 0; i < run_size; i++) {
@@ -72,6 +73,7 @@ int main(int ac, char **av) {
 		if (i == run_size - 5) {
 			btrfs_commit_transaction(trans, root);
 			trans = btrfs_start_transaction(root, 1);
+			BUG_ON(IS_ERR(trans));
 		}
 	}
 	btrfs_commit_transaction(trans, root);
@@ -114,6 +116,7 @@ int main(int ac, char **av) {
 	i = 0;
 	srand(55);
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	for (i = 0 ; i < run_size/4; i++) {
 		num = next_key(i, max_key);
 		ins.objectid = num;
@@ -138,6 +141,7 @@ int main(int ac, char **av) {
 		exit(1);
 	}
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	srand(128);
 	for (i = 0; i < run_size; i++) {
 		num = next_key(i, max_key);
@@ -175,6 +179,7 @@ int main(int ac, char **av) {
 	}
 	printf("starting big long delete run\n");
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	while(root->node && btrfs_header_nritems(root->node) > 0) {
 		struct extent_buffer *leaf;
 		int slot;
diff --git a/random-test.c b/random-test.c
index 410a110b..d5f830a9 100644
--- a/random-test.c
+++ b/random-test.c
@@ -380,6 +380,7 @@ int main(int ac, char **av)
 	}
 	printf("initial fill\n");
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	ret = fill_tree(trans, root, &radix, init_fill_count);
 	printf("starting run\n");
 	if (ret) {
diff --git a/utils.c b/utils.c
index bb049133..2d0ff8b3 100644
--- a/utils.c
+++ b/utils.c
@@ -1229,6 +1229,7 @@ static int set_label_unmounted(const char *dev, const char *label)
 		return -1;
 
 	trans = btrfs_start_transaction(root, 1);
+	BUG_ON(IS_ERR(trans));
 	__strncpy_null(root->fs_info->super_copy->label, label, BTRFS_LABEL_SIZE - 1);
 
 	btrfs_commit_transaction(trans, root);
-- 
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