From 7f913c7cfec62b91ceb4383c4dfb481092ae9d20 Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@suse.com>
Patch-mainline: v5.7-rc1
Git-commit: 7f913c7cfec62b91ceb4383c4dfb481092ae9d20
References: bsc#1171417
Date: Mon, 17 Feb 2020 14:16:53 +0800
Subject: [PATCH 2/3] btrfs: relocation: Check cancel request after each data
page read
When relocating a data extents with large large data extents, we spend
most of our time in relocate_file_extent_cluster() at stage "moving data
extents":
1) | btrfs_relocate_block_group [btrfs]() {
1) | relocate_file_extent_cluster [btrfs]() {
1) $ 6586769 us | }
1) + 18.260 us | relocate_file_extent_cluster [btrfs]();
1) + 15.770 us | relocate_file_extent_cluster [btrfs]();
1) $ 8916340 us | }
1) | btrfs_relocate_block_group [btrfs]() {
1) | relocate_file_extent_cluster [btrfs]() {
1) $ 11611586 us | }
1) + 16.930 us | relocate_file_extent_cluster [btrfs]();
1) + 15.870 us | relocate_file_extent_cluster [btrfs]();
1) $ 14986130 us | }
To make data relocation cancelling quicker, add extra balance cancelling
check after each page read in relocate_file_extent_cluster().
Cleanup and error handling uses the same mechanism as if the whole
process finished
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/relocation.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 0238801e6408..a4edb821990f 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -3445,6 +3445,10 @@ static int relocate_file_extent_cluster(struct inode *inode,
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
balance_dirty_pages_ratelimited(inode->i_mapping);
btrfs_throttle(fs_info);
+ if (btrfs_should_cancel_balance(fs_info)) {
+ ret = -ECANCELED;
+ goto out;
+ }
}
WARN_ON(nr != cluster->nr);
out:
@@ -4259,6 +4263,14 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
backref_cache_cleanup(&rc->backref_cache);
btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1);
+ /*
+ * Even in the case when the relocation is cancelled, we should all go
+ * through prepare_to_merge() and merge_reloc_roots().
+ *
+ * For error (including cancelled balance), prepare_to_merge() will
+ * mark all reloc trees orphan, then queue them for cleanup in
+ * merge_reloc_roots()
+ */
err = prepare_to_merge(rc, err);
merge_reloc_roots(rc);
--
2.26.2