From: Christoph Hellwig hch@lst.de
[ Upstream commit 50b21d7a066f9a702b1d54ca11fc577302e875cb ]
Stop trying to cluster writes of multiple extent_buffers into a single bio. There is no need for that as the blk_plug mechanism used all the way up in writeback_inodes_wb gives us the same I/O pattern even with multiple bios. Removing the clustering simplifies lock_extent_buffer_for_io a lot and will also allow passing the eb as private data to the end I/O handler.
Reviewed-by: Johannes Thumshirn johannes.thumshirn@wdc.com Reviewed-by: Josef Bacik josef@toxicpanda.com Signed-off-by: Christoph Hellwig hch@lst.de Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Stable-dep-of: 7027f87108ce ("btrfs: don't treat zoned writeback as being from an async helper thread") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/extent_io.c | 102 ++++++++++++++++--------------------------- 1 file changed, 37 insertions(+), 65 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 28d0792359968..0c9538bb3c852 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1669,41 +1669,24 @@ static void end_extent_buffer_writeback(struct extent_buffer *eb) /* * Lock extent buffer status and pages for writeback. * - * May try to flush write bio if we can't get the lock. - * * Return %false if the extent buffer doesn't need to be submitted (e.g. the * extent buffer is not dirty) * Return %true is the extent buffer is submitted to bio. */ static noinline_for_stack bool lock_extent_buffer_for_io(struct extent_buffer *eb, - struct btrfs_bio_ctrl *bio_ctrl) + struct writeback_control *wbc) { struct btrfs_fs_info *fs_info = eb->fs_info; - int i, num_pages; - int flush = 0; bool ret = false; + int i;
- if (!btrfs_try_tree_write_lock(eb)) { - submit_write_bio(bio_ctrl, 0); - flush = 1; - btrfs_tree_lock(eb); - } - - if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) { + btrfs_tree_lock(eb); + while (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) { btrfs_tree_unlock(eb); - if (bio_ctrl->wbc->sync_mode != WB_SYNC_ALL) + if (wbc->sync_mode != WB_SYNC_ALL) return false; - if (!flush) { - submit_write_bio(bio_ctrl, 0); - flush = 1; - } - while (1) { - wait_on_extent_buffer_writeback(eb); - btrfs_tree_lock(eb); - if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) - break; - btrfs_tree_unlock(eb); - } + wait_on_extent_buffer_writeback(eb); + btrfs_tree_lock(eb); }
/* @@ -1735,19 +1718,8 @@ static noinline_for_stack bool lock_extent_buffer_for_io(struct extent_buffer *e if (!ret || fs_info->nodesize < PAGE_SIZE) return ret;
- num_pages = num_extent_pages(eb); - for (i = 0; i < num_pages; i++) { - struct page *p = eb->pages[i]; - - if (!trylock_page(p)) { - if (!flush) { - submit_write_bio(bio_ctrl, 0); - flush = 1; - } - lock_page(p); - } - } - + for (i = 0; i < num_extent_pages(eb); i++) + lock_page(eb->pages[i]); return ret; }
@@ -1977,11 +1949,16 @@ static void prepare_eb_write(struct extent_buffer *eb) * Page locking is only utilized at minimum to keep the VMM code happy. */ static void write_one_subpage_eb(struct extent_buffer *eb, - struct btrfs_bio_ctrl *bio_ctrl) + struct writeback_control *wbc) { struct btrfs_fs_info *fs_info = eb->fs_info; struct page *page = eb->pages[0]; bool no_dirty_ebs = false; + struct btrfs_bio_ctrl bio_ctrl = { + .wbc = wbc, + .opf = REQ_OP_WRITE | wbc_to_write_flags(wbc), + .end_io_func = end_bio_subpage_eb_writepage, + };
prepare_eb_write(eb);
@@ -1995,40 +1972,43 @@ static void write_one_subpage_eb(struct extent_buffer *eb, if (no_dirty_ebs) clear_page_dirty_for_io(page);
- bio_ctrl->end_io_func = end_bio_subpage_eb_writepage; - - submit_extent_page(bio_ctrl, eb->start, page, eb->len, + submit_extent_page(&bio_ctrl, eb->start, page, eb->len, eb->start - page_offset(page)); unlock_page(page); + submit_one_bio(&bio_ctrl); /* * Submission finished without problem, if no range of the page is * dirty anymore, we have submitted a page. Update nr_written in wbc. */ if (no_dirty_ebs) - bio_ctrl->wbc->nr_to_write--; + wbc->nr_to_write--; }
static noinline_for_stack void write_one_eb(struct extent_buffer *eb, - struct btrfs_bio_ctrl *bio_ctrl) + struct writeback_control *wbc) { u64 disk_bytenr = eb->start; int i, num_pages; + struct btrfs_bio_ctrl bio_ctrl = { + .wbc = wbc, + .opf = REQ_OP_WRITE | wbc_to_write_flags(wbc), + .end_io_func = end_bio_extent_buffer_writepage, + };
prepare_eb_write(eb);
- bio_ctrl->end_io_func = end_bio_extent_buffer_writepage; - num_pages = num_extent_pages(eb); for (i = 0; i < num_pages; i++) { struct page *p = eb->pages[i];
clear_page_dirty_for_io(p); set_page_writeback(p); - submit_extent_page(bio_ctrl, disk_bytenr, p, PAGE_SIZE, 0); + submit_extent_page(&bio_ctrl, disk_bytenr, p, PAGE_SIZE, 0); disk_bytenr += PAGE_SIZE; - bio_ctrl->wbc->nr_to_write--; + wbc->nr_to_write--; unlock_page(p); } + submit_one_bio(&bio_ctrl); }
/* @@ -2045,7 +2025,7 @@ static noinline_for_stack void write_one_eb(struct extent_buffer *eb, * Return >=0 for the number of submitted extent buffers. * Return <0 for fatal error. */ -static int submit_eb_subpage(struct page *page, struct btrfs_bio_ctrl *bio_ctrl) +static int submit_eb_subpage(struct page *page, struct writeback_control *wbc) { struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb); int submitted = 0; @@ -2097,8 +2077,8 @@ static int submit_eb_subpage(struct page *page, struct btrfs_bio_ctrl *bio_ctrl) if (!eb) continue;
- if (lock_extent_buffer_for_io(eb, bio_ctrl)) { - write_one_subpage_eb(eb, bio_ctrl); + if (lock_extent_buffer_for_io(eb, wbc)) { + write_one_subpage_eb(eb, wbc); submitted++; } free_extent_buffer(eb); @@ -2126,7 +2106,7 @@ static int submit_eb_subpage(struct page *page, struct btrfs_bio_ctrl *bio_ctrl) * previous call. * Return <0 for fatal error. */ -static int submit_eb_page(struct page *page, struct btrfs_bio_ctrl *bio_ctrl, +static int submit_eb_page(struct page *page, struct writeback_control *wbc, struct extent_buffer **eb_context) { struct address_space *mapping = page->mapping; @@ -2138,7 +2118,7 @@ static int submit_eb_page(struct page *page, struct btrfs_bio_ctrl *bio_ctrl, return 0;
if (btrfs_sb(page->mapping->host->i_sb)->nodesize < PAGE_SIZE) - return submit_eb_subpage(page, bio_ctrl); + return submit_eb_subpage(page, wbc);
spin_lock(&mapping->private_lock); if (!PagePrivate(page)) { @@ -2171,8 +2151,7 @@ static int submit_eb_page(struct page *page, struct btrfs_bio_ctrl *bio_ctrl, * If for_sync, this hole will be filled with * trasnsaction commit. */ - if (bio_ctrl->wbc->sync_mode == WB_SYNC_ALL && - !bio_ctrl->wbc->for_sync) + if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync) ret = -EAGAIN; else ret = 0; @@ -2182,12 +2161,12 @@ static int submit_eb_page(struct page *page, struct btrfs_bio_ctrl *bio_ctrl,
*eb_context = eb;
- if (!lock_extent_buffer_for_io(eb, bio_ctrl)) { + if (!lock_extent_buffer_for_io(eb, wbc)) { btrfs_revert_meta_write_pointer(cache, eb); if (cache) btrfs_put_block_group(cache); free_extent_buffer(eb); - return ret; + return 0; } if (cache) { /* @@ -2196,7 +2175,7 @@ static int submit_eb_page(struct page *page, struct btrfs_bio_ctrl *bio_ctrl, btrfs_schedule_zone_finish_bg(cache, eb); btrfs_put_block_group(cache); } - write_one_eb(eb, bio_ctrl); + write_one_eb(eb, wbc); free_extent_buffer(eb); return 1; } @@ -2205,11 +2184,6 @@ int btree_write_cache_pages(struct address_space *mapping, struct writeback_control *wbc) { struct extent_buffer *eb_context = NULL; - struct btrfs_bio_ctrl bio_ctrl = { - .wbc = wbc, - .opf = REQ_OP_WRITE | wbc_to_write_flags(wbc), - .extent_locked = 0, - }; struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info; int ret = 0; int done = 0; @@ -2251,7 +2225,7 @@ int btree_write_cache_pages(struct address_space *mapping, for (i = 0; i < nr_folios; i++) { struct folio *folio = fbatch.folios[i];
- ret = submit_eb_page(&folio->page, &bio_ctrl, &eb_context); + ret = submit_eb_page(&folio->page, wbc, &eb_context); if (ret == 0) continue; if (ret < 0) { @@ -2312,8 +2286,6 @@ int btree_write_cache_pages(struct address_space *mapping, ret = 0; if (!ret && BTRFS_FS_ERROR(fs_info)) ret = -EROFS; - submit_write_bio(&bio_ctrl, ret); - btrfs_zoned_meta_io_unlock(fs_info); return ret; }