diff options
| author | Filipe Manana <fdmanana@suse.com> | 2023-07-26 18:57:11 +0300 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2023-08-21 15:52:18 +0300 |
| commit | 2ee70ed19ccd9c95c188816b65dacf3fca1f5565 (patch) | |
| tree | ecb35910fc630d8d68cc041c9c1d7d024bce34e9 /fs/btrfs | |
| parent | 2391245ac2875f784335b9148079c6e73639a5f7 (diff) | |
| download | linux-2ee70ed19ccd9c95c188816b65dacf3fca1f5565.tar.xz | |
btrfs: avoid starting and committing empty transaction when flushing space
When flushing space and we are in the COMMIT_TRANS state, we join a
transaction with btrfs_join_transaction() and then commit the returned
transaction. However btrfs_join_transaction() starts a new transaction if
there is none currently open, which is pointless since comitting a new,
empty transaction, doesn't achieve anything, it only wastes time, IO and
creates an unnecessary rotation of the backup roots.
So use btrfs_attach_transaction_barrier() to avoid starting a new
transaction. This also waits for any ongoing transaction that is
committing (state >= TRANS_STATE_COMMIT_DOING) to fully complete, and
therefore wait for all the extents that were pinned during the
transaction's lifetime to be unpinned.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/space-info.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c index 2db92a201697..17c86db7b1b1 100644 --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -814,9 +814,18 @@ static void flush_space(struct btrfs_fs_info *fs_info, break; case COMMIT_TRANS: ASSERT(current->journal_info == NULL); - trans = btrfs_join_transaction(root); + /* + * We don't want to start a new transaction, just attach to the + * current one or wait it fully commits in case its commit is + * happening at the moment. Note: we don't use a nostart join + * because that does not wait for a transaction to fully commit + * (only for it to be unblocked, state TRANS_STATE_UNBLOCKED). + */ + trans = btrfs_attach_transaction_barrier(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); + if (ret == -ENOENT) + ret = 0; break; } ret = btrfs_commit_transaction(trans); |