Commit 3612b495 authored by Tsutomu Itoh's avatar Tsutomu Itoh Committed by Chris Mason
Browse files

btrfs: fix return value check of btrfs_join_transaction() 



The error check of btrfs_join_transaction()/btrfs_join_transaction_nolock()
is added, and the mistake of the error check in several places is
corrected.

For more stable Btrfs, I think that we should reduce BUG_ON().
But, I think that long time is necessary for this.
So, I propose this patch as a short-term solution.

With this patch:
 - To more stable Btrfs, the part that should be corrected is clarified.
 - The panic isn't done by the NULL pointer reference etc. (even if
   BUG_ON() is increased temporarily)
 - The error code is returned in the place where the error can be easily
   returned.

As a long-term plan:
 - BUG_ON() is reduced by using the forced-readonly framework, etc.

Signed-off-by: default avatarTsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 34d19bad

fs/btrfs/disk-io.c

+5 −0
Original line number Diff line number Diff line
@@ -1550,6 +1550,7 @@ static int transaction_kthread(void *arg) 
		spin_unlock(&root->fs_info->new_trans_lock);



		trans = btrfs_join_transaction(root, 1);

		BUG_ON(IS_ERR(trans));

		if (transid == trans->transid) {

			ret = btrfs_commit_transaction(trans, root);

			BUG_ON(ret);
@@ -2464,10 +2465,14 @@ int btrfs_commit_super(struct btrfs_root *root) 
	up_write(&root->fs_info->cleanup_work_sem);



	trans = btrfs_join_transaction(root, 1);

	if (IS_ERR(trans))

		return PTR_ERR(trans);

	ret = btrfs_commit_transaction(trans, root);

	BUG_ON(ret);

	/* run commit again to drop the original snapshot */

	trans = btrfs_join_transaction(root, 1);

	if (IS_ERR(trans))

		return PTR_ERR(trans);

	btrfs_commit_transaction(trans, root);

	ret = btrfs_write_and_wait_transaction(NULL, root);

	BUG_ON(ret);

fs/btrfs/extent-tree.c

+1 −1
Original line number Diff line number Diff line
@@ -7478,7 +7478,7 @@ int btrfs_drop_dead_reloc_roots(struct btrfs_root *root) 
		BUG_ON(reloc_root->commit_root != NULL);

		while (1) {

			trans = btrfs_join_transaction(root, 1);

			BUG_ON(!trans);

			BUG_ON(IS_ERR(trans));



			mutex_lock(&root->fs_info->drop_mutex);

			ret = btrfs_drop_snapshot(trans, reloc_root);

fs/btrfs/inode.c

+16 −8
Original line number Diff line number Diff line
@@ -416,7 +416,7 @@ again: 
	}

	if (start == 0) {

		trans = btrfs_join_transaction(root, 1);

		BUG_ON(!trans);

		BUG_ON(IS_ERR(trans));

		btrfs_set_trans_block_group(trans, inode);

		trans->block_rsv = &root->fs_info->delalloc_block_rsv;
@@ -612,6 +612,7 @@ retry: 
			    GFP_NOFS);



		trans = btrfs_join_transaction(root, 1);

		BUG_ON(IS_ERR(trans));

		ret = btrfs_reserve_extent(trans, root,

					   async_extent->compressed_size,

					   async_extent->compressed_size,
@@ -771,7 +772,7 @@ static noinline int cow_file_range(struct inode *inode, 


	BUG_ON(root == root->fs_info->tree_root);

	trans = btrfs_join_transaction(root, 1);

	BUG_ON(!trans);

	BUG_ON(IS_ERR(trans));

	btrfs_set_trans_block_group(trans, inode);

	trans->block_rsv = &root->fs_info->delalloc_block_rsv;
@@ -1049,7 +1050,7 @@ static noinline int run_delalloc_nocow(struct inode *inode, 
	} else {

		trans = btrfs_join_transaction(root, 1);

	}

	BUG_ON(!trans);

	BUG_ON(IS_ERR(trans));



	cow_start = (u64)-1;

	cur_offset = start;
@@ -1704,7 +1705,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) 
				trans = btrfs_join_transaction_nolock(root, 1);

			else

				trans = btrfs_join_transaction(root, 1);

			BUG_ON(!trans);

			BUG_ON(IS_ERR(trans));

			btrfs_set_trans_block_group(trans, inode);

			trans->block_rsv = &root->fs_info->delalloc_block_rsv;

			ret = btrfs_update_inode(trans, root, inode);
@@ -1721,6 +1722,7 @@ static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end) 
		trans = btrfs_join_transaction_nolock(root, 1);

	else

		trans = btrfs_join_transaction(root, 1);

	BUG_ON(IS_ERR(trans));

	btrfs_set_trans_block_group(trans, inode);

	trans->block_rsv = &root->fs_info->delalloc_block_rsv;
@@ -2382,6 +2384,7 @@ void btrfs_orphan_cleanup(struct btrfs_root *root) 


	if (root->orphan_block_rsv || root->orphan_item_inserted) {

		trans = btrfs_join_transaction(root, 1);

		BUG_ON(IS_ERR(trans));

		btrfs_end_transaction(trans, root);

	}
@@ -4350,6 +4353,8 @@ int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) 
			trans = btrfs_join_transaction_nolock(root, 1);

		else

			trans = btrfs_join_transaction(root, 1);

		if (IS_ERR(trans))

			return PTR_ERR(trans);

		btrfs_set_trans_block_group(trans, inode);

		if (nolock)

			ret = btrfs_end_transaction_nolock(trans, root);
@@ -4375,6 +4380,7 @@ void btrfs_dirty_inode(struct inode *inode) 
		return;



	trans = btrfs_join_transaction(root, 1);

	BUG_ON(IS_ERR(trans));

	btrfs_set_trans_block_group(trans, inode);



	ret = btrfs_update_inode(trans, root, inode);
@@ -5179,6 +5185,8 @@ again: 
				em = NULL;

				btrfs_release_path(root, path);

				trans = btrfs_join_transaction(root, 1);

				if (IS_ERR(trans))

					return ERR_CAST(trans);

				goto again;

			}

			map = kmap(page);
@@ -5283,8 +5291,8 @@ static struct extent_map *btrfs_new_extent_direct(struct inode *inode, 
	btrfs_drop_extent_cache(inode, start, start + len - 1, 0);



	trans = btrfs_join_transaction(root, 0);

	if (!trans)

		return ERR_PTR(-ENOMEM);

	if (IS_ERR(trans))

		return ERR_CAST(trans);



	trans->block_rsv = &root->fs_info->delalloc_block_rsv;
@@ -5508,7 +5516,7 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, 
		 * while we look for nocow cross refs

		 */

		trans = btrfs_join_transaction(root, 0);

		if (!trans)

		if (IS_ERR(trans))

			goto must_cow;



		if (can_nocow_odirect(trans, inode, start, len) == 1) {
@@ -5643,7 +5651,7 @@ again: 
	BUG_ON(!ordered);



	trans = btrfs_join_transaction(root, 1);

	if (!trans) {

	if (IS_ERR(trans)) {

		err = -ENOMEM;

		goto out;

	}

fs/btrfs/ioctl.c

+1 −1
Original line number Diff line number Diff line
@@ -203,7 +203,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) 




	trans = btrfs_join_transaction(root, 1);

	BUG_ON(!trans);

	BUG_ON(IS_ERR(trans));



	ret = btrfs_update_inode(trans, root, inode);

	BUG_ON(ret);

fs/btrfs/relocation.c

+23 −3
Original line number Diff line number Diff line
@@ -2147,6 +2147,12 @@ again: 
	}



	trans = btrfs_join_transaction(rc->extent_root, 1);

	if (IS_ERR(trans)) {

		if (!err)

			btrfs_block_rsv_release(rc->extent_root,

						rc->block_rsv, num_bytes);

		return PTR_ERR(trans);

	}



	if (!err) {

		if (num_bytes != rc->merging_rsv_size) {
@@ -3222,6 +3228,7 @@ truncate: 
	trans = btrfs_join_transaction(root, 0);

	if (IS_ERR(trans)) {

		btrfs_free_path(path);

		ret = PTR_ERR(trans);

		goto out;

	}
@@ -3628,6 +3635,7 @@ int prepare_to_relocate(struct reloc_control *rc) 
	set_reloc_control(rc);



	trans = btrfs_join_transaction(rc->extent_root, 1);

	BUG_ON(IS_ERR(trans));

	btrfs_commit_transaction(trans, rc->extent_root);

	return 0;

}
@@ -3804,6 +3812,9 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc) 


	/* get rid of pinned extents */

	trans = btrfs_join_transaction(rc->extent_root, 1);

	if (IS_ERR(trans))

		err = PTR_ERR(trans);

	else

		btrfs_commit_transaction(trans, rc->extent_root);

out_free:

	btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
@@ -4125,6 +4136,11 @@ int btrfs_recover_relocation(struct btrfs_root *root) 
	set_reloc_control(rc);



	trans = btrfs_join_transaction(rc->extent_root, 1);

	if (IS_ERR(trans)) {

		unset_reloc_control(rc);

		err = PTR_ERR(trans);

		goto out_free;

	}



	rc->merge_reloc_tree = 1;
@@ -4154,9 +4170,13 @@ int btrfs_recover_relocation(struct btrfs_root *root) 
	unset_reloc_control(rc);



	trans = btrfs_join_transaction(rc->extent_root, 1);

	if (IS_ERR(trans))

		err = PTR_ERR(trans);

	else

		btrfs_commit_transaction(trans, rc->extent_root);

out:

out_free:

	kfree(rc);

out:

	while (!list_empty(&reloc_roots)) {

		reloc_root = list_entry(reloc_roots.next,

					struct btrfs_root, root_list);

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