From 0420177c08b2d86034a98d45b7d3609bdc986fd2 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Mon, 14 Sep 2020 12:37:04 +0300 Subject: [PATCH] btrfs: simplify metadata pages reading Metadata pages currently use __do_readpage to read metadata pages, unfortunately this function is also used to deal with ordinary data pages. This makes the metadata pages reading code to go through multiple hoops in order to adhere to __do_readpage invariants. Most of these are necessary for data pages which could be compressed. For metadata it's enough to simply build a bio and submit it. To this effect simply call submit_extent_page directly from read_extent_buffer_pages which is the only callpath used to populate extent_buffers with data. This in turn enables further cleanups. Reviewed-by: Qu Wenruo Reviewed-by: Johannes Thumshirn Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index a1e070ec7ad8a..0a6cda4c30ed7 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5573,20 +5573,19 @@ int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num) } ClearPageError(page); - err = __extent_read_full_page(page, - btree_get_extent, &bio, - mirror_num, &bio_flags, - REQ_META); + err = submit_extent_page(REQ_OP_READ | REQ_META, NULL, + page, page_offset(page), PAGE_SIZE, 0, + &bio, end_bio_extent_readpage, + mirror_num, 0, 0, false); if (err) { - ret = err; /* - * We use &bio in above __extent_read_full_page, - * so we ensure that if it returns error, the - * current page fails to add itself to bio and - * it's been unlocked. - * - * We must dec io_pages by ourselves. + * We failed to submit the bio so it's the + * caller's responsibility to perform cleanup + * i.e unlock page/set error bit. */ + ret = err; + SetPageError(page); + unlock_page(page); atomic_dec(&eb->io_pages); } } else { -- 2.30.2