From a023127a28d4b8d651d3ccb41dd7da2ba534390a Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Wed, 2 Nov 2022 16:45:28 -0400 Subject: [PATCH] bcachefs: Eliminate function calls in DIO fastpaths We can assume that usually buffered and O_DIRECT IO won't be mixed, and the calls to flush the page cache won't be needed. Signed-off-by: Kent Overstreet --- fs/bcachefs/fs-io.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/fs/bcachefs/fs-io.c b/fs/bcachefs/fs-io.c index 185a37a6705e8..a1767ee855910 100644 --- a/fs/bcachefs/fs-io.c +++ b/fs/bcachefs/fs-io.c @@ -77,7 +77,7 @@ struct dio_read { }; /* pagecache_block must be held */ -static int write_invalidate_inode_pages_range(struct address_space *mapping, +static noinline int write_invalidate_inode_pages_range(struct address_space *mapping, loff_t start, loff_t end) { int ret; @@ -1693,11 +1693,13 @@ ssize_t bch2_read_iter(struct kiocb *iocb, struct iov_iter *iter) if (iocb->ki_flags & IOCB_DIRECT) { struct blk_plug plug; - ret = filemap_write_and_wait_range(mapping, - iocb->ki_pos, - iocb->ki_pos + count - 1); - if (ret < 0) - return ret; + if (unlikely(mapping->nrpages)) { + ret = filemap_write_and_wait_range(mapping, + iocb->ki_pos, + iocb->ki_pos + count - 1); + if (ret < 0) + return ret; + } file_accessed(file); @@ -1961,11 +1963,13 @@ ssize_t bch2_direct_write(struct kiocb *req, struct iov_iter *iter) dio->op.opts.data_replicas)) goto err_put_bio; - ret = write_invalidate_inode_pages_range(mapping, - req->ki_pos, - req->ki_pos + iter->count - 1); - if (unlikely(ret)) - goto err_put_bio; + if (unlikely(mapping->nrpages)) { + ret = write_invalidate_inode_pages_range(mapping, + req->ki_pos, + req->ki_pos + iter->count - 1); + if (unlikely(ret)) + goto err_put_bio; + } ret = bch2_dio_write_loop(dio); err: -- 2.30.2