From: Qu Wenruo <wqu@suse.com>
To: linux-btrfs@vger.kernel.org
Subject: [PATCH 25/27] btrfs: allow subpage to compress a range which only covers one page
Date: Tue, 13 Jul 2021 14:15:14 +0800 [thread overview]
Message-ID: <20210713061516.163318-26-wqu@suse.com> (raw)
In-Reply-To: <20210713061516.163318-1-wqu@suse.com>
[BUG]
With expertimental subpage compression write enabled, btrfs still refuse
to compress a completely valid range:
mkfs.btrfs -f -s 4k $dev
mount $dev -o compress $mnt
xfs_io -f -c "pwrite 0 64K" $mnt/file
umount $mnt
The result extent is uncompressed.
[CAUSE]
It turns out we have extra check on whether we should compress the range
in compress_file_range().
The check looks like:
if (nr_pages > 1 && inode_need_compress(BTRFS_I(inode), start, end)) {
This means, we will only compress range which covers more than one page.
This check no longer makes sense for subpage, as one page can contain
several sectors.
[FIX]
Don't use @nr_pages, but directly compare @total_compressed against
@blocksize to determine whether we need to do compression.
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
fs/btrfs/inode.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1432e268c13e..1cab1e99e46e 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -630,7 +630,8 @@ static noinline int compress_file_range(struct async_chunk *async_chunk)
* inode has not been flagged as nocompress. This flag can
* change at any time if we discover bad compression ratios.
*/
- if (nr_pages > 1 && inode_need_compress(BTRFS_I(inode), start, end)) {
+ if (total_compressed > blocksize &&
+ inode_need_compress(BTRFS_I(inode), start, end)) {
WARN_ON(pages);
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
if (!pages) {
--
2.32.0
next prev parent reply other threads:[~2021-07-13 6:15 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 6:14 [PATCH 00/27] btrfs: limited subpage compressed write support Qu Wenruo
2021-07-13 6:14 ` [PATCH 01/27] btrfs: remove unused parameter @nr_pages in add_ra_bio_pages() Qu Wenruo
2021-07-13 6:14 ` [PATCH 02/27] btrfs: remove unnecessary parameter @delalloc_start for writepage_delalloc() Qu Wenruo
2021-07-13 6:14 ` [PATCH 03/27] btrfs: use async_chunk::async_cow to replace the confusing pending pointer Qu Wenruo
2021-07-13 7:36 ` Nikolay Borisov
2021-07-13 6:14 ` [PATCH 04/27] btrfs: don't pass compressed pages to btrfs_writepage_endio_finish_ordered() Qu Wenruo
2021-07-13 6:14 ` [PATCH 05/27] btrfs: make add_ra_bio_pages() to be subpage compatible Qu Wenruo
2021-07-13 6:14 ` [PATCH 06/27] btrfs: introduce compressed_bio::pending_sectors to trace compressed bio more elegantly Qu Wenruo
2021-07-13 6:14 ` [PATCH 07/27] btrfs: add subpage checked_bitmap to make PageChecked flag to be subpage compatible Qu Wenruo
2021-07-16 7:54 ` Qu Wenruo
2021-07-13 6:14 ` [PATCH 08/27] btrfs: handle errors properly inside btrfs_submit_compressed_read() Qu Wenruo
2021-07-13 6:14 ` [PATCH 09/27] btrfs: handle errors properly inside btrfs_submit_compressed_write() Qu Wenruo
2021-07-13 6:14 ` [PATCH 10/27] btrfs: introduce submit_compressed_bio() for compression Qu Wenruo
2021-07-13 6:15 ` [PATCH 11/27] btrfs: introduce alloc_compressed_bio() " Qu Wenruo
2021-07-13 6:15 ` [PATCH 12/27] btrfs: make btrfs_submit_compressed_read() to determine stripe boundary at bio allocation time Qu Wenruo
2021-07-13 6:15 ` [PATCH 13/27] btrfs: make btrfs_submit_compressed_write() " Qu Wenruo
2021-07-13 6:15 ` [PATCH 14/27] btrfs: remove unused function btrfs_bio_fits_in_stripe() Qu Wenruo
2021-07-13 6:15 ` [PATCH 15/27] btrfs: refactor submit_compressed_extents() Qu Wenruo
2021-07-13 6:15 ` [PATCH 16/27] btrfs: cleanup for extent_write_locked_range() Qu Wenruo
2021-07-13 6:15 ` [PATCH 17/27] btrfs: make compress_file_range() to be subpage compatible Qu Wenruo
2021-07-13 6:15 ` [PATCH 18/27] btrfs: make btrfs_submit_compressed_write() " Qu Wenruo
2021-07-13 6:15 ` [PATCH 19/27] btrfs: make end_compressed_bio_writeback() to be subpage compatble Qu Wenruo
2021-07-13 6:15 ` [PATCH 20/27] btrfs: make extent_write_locked_range() to be subpage compatible Qu Wenruo
2021-07-13 6:15 ` [PATCH 21/27] btrfs: extract uncompressed async extent submission code into a new helper Qu Wenruo
2021-07-13 6:15 ` [PATCH 22/27] btrfs: rework lzo_compress_pages() to make it subpage compatible Qu Wenruo
2021-07-13 6:15 ` [PATCH 23/27] btrfs: teach __extent_writepage() to handle locked page differently Qu Wenruo
2021-07-13 6:15 ` [PATCH 24/27] btrfs: allow page to be unlocked by btrfs_page_end_writer_lock() even if it's locked by plain page_lock() Qu Wenruo
2021-07-13 6:15 ` Qu Wenruo [this message]
2021-07-13 6:15 ` [PATCH 26/27] btrfs: don't run delalloc range which is beyond the locked_page to prevent deadlock for subpage compression Qu Wenruo
2021-07-13 6:15 ` [PATCH 27/27] btrfs: only allow subpage compression if the range is fully page aligned Qu Wenruo
2021-07-16 9:11 ` [PATCH 00/27] btrfs: limited subpage compressed write support Qu Wenruo
2021-07-20 5:00 ` Qu Wenruo
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