Since most metadata reservation calls can return -EINTR when get
interruped by fatal signal, we need to review the all the metadata
reservation call sites.
In relocation code, the metadata reservation happens in the following
sites:
- btrfs_block_rsv_refill() in merge_reloc_root()
merge_reloc_root() is a pretty critial section, we don't want get
interrupted by signal, so change the flush status to
BTRFS_RESERVE_FLUSH_LIMIT, so it won't get interrupted by signal.
Since such change can be ENPSPC-prone, also shrink the amount of
metadata to reserve a little to avoid deadly ENOSPC there.
- btrfs_block_rsv_refill() in reserve_metadata_space()
It calls with BTRFS_RESERVE_FLUSH_LIMIT, which won't get interrupred
by signal.
- btrfs_block_rsv_refill() in prepare_to_relocate()
- btrfs_block_rsv_add() in prepare_to_relocate()
- btrfs_block_rsv_refill() in relocate_block_group()
- btrfs_delalloc_reserve_metadata() in relocate_file_extent_cluster()
- btrfs_start_transaction() in relocate_block_group()
- btrfs_start_transaction() in create_reloc_inode()
Can be interruped by fatal signal and we can handle it easily.
For these call sites, just catch the -EINTR value in btrfs_balance()
and count them as canceled.
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
---
fs/btrfs/relocation.c | 4 ++--
fs/btrfs/volumes.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 2b869fb2e62c..29bbead29be5 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1686,12 +1686,12 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
btrfs_unlock_up_safe(path, 0);
}
- min_reserved = fs_info->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
+ min_reserved = fs_info->nodesize * level * 2;
memset(&next_key, 0, sizeof(next_key));
while (1) {
ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
- BTRFS_RESERVE_FLUSH_ALL);
+ BTRFS_RESERVE_FLUSH_LIMIT);
if (ret) {
err = ret;
goto out;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index aabc6c922e04..d60df30bdc47 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -4135,7 +4135,7 @@ int btrfs_balance(struct btrfs_fs_info *fs_info,
mutex_lock(&fs_info->balance_mutex);
if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req))
btrfs_info(fs_info, "balance: paused");
- else if (ret == -ECANCELED && atomic_read(&fs_info->balance_cancel_req))
+ else if (ret == -ECANCELED || ret == -EINTR)
btrfs_info(fs_info, "balance: canceled");
else
btrfs_info(fs_info, "balance: ended with status: %d", ret);
--
2.27.0
