btrfs: btrfs_wait_tree_block_writeback can be void return

Nothing checks its return value.

Is it safe to skip checking return value of btrfs_wait_tree_block_writeback?

Liu Bo: I think yes, it's used in walk_log_tree which is called in two
places, free_log_tree and log replay.  For free_log_tree, it waits for
any running writeback of the extent buffer under freeing to finish in
case we need to access the eb pointer from page->private, and it's OK to
not check the return value, while for log replay, it's doesn't wait
because wc->wait is not set. So neither cares about the writeback error.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
[ added more explanation to changelog, from Liu Bo ]
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Jeff Layton 2017-05-25 06:39:52 -04:00 committed by David Sterba
parent 118c701e20
commit 3189ff7786
2 changed files with 4 additions and 4 deletions

View file

@ -1223,10 +1223,10 @@ int btrfs_write_tree_block(struct extent_buffer *buf)
buf->start + buf->len - 1);
}
int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
{
return filemap_fdatawait_range(buf->pages[0]->mapping,
buf->start, buf->start + buf->len - 1);
filemap_fdatawait_range(buf->pages[0]->mapping,
buf->start, buf->start + buf->len - 1);
}
struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,

View file

@ -127,7 +127,7 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
extent_submit_bio_hook_t *submit_bio_done);
unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info);
int btrfs_write_tree_block(struct extent_buffer *buf);
int btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
void btrfs_wait_tree_block_writeback(struct extent_buffer *buf);
int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info);
int btrfs_add_log_tree(struct btrfs_trans_handle *trans,