From f00c42dd4cc8b856e68638e6a88b51f88b8e849e Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 9 Oct 2020 09:28:21 -0400 Subject: [PATCH] btrfs: introduce a FORCE_COMMIT_TRANS flush operation Solely for preemptive flushing, we want to be able to force the transaction commit without any of the ambiguity of may_commit_transaction(). This is because may_commit_transaction() checks tickets and such, and in preemptive flushing we already know it'll be helpful, so use this to keep the code nice and clean and straightforward. Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik [ add comment ] Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 1 + fs/btrfs/space-info.c | 14 ++++++++++++++ include/trace/events/btrfs.h | 3 ++- 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 7d8660227520..90726954b883 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2740,6 +2740,7 @@ enum btrfs_flush_state { ALLOC_CHUNK_FORCE = 8, RUN_DELAYED_IPUTS = 9, COMMIT_TRANS = 10, + FORCE_COMMIT_TRANS = 11, }; int btrfs_subvolume_reserve_metadata(struct btrfs_root *root, diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c index 711beacd75d6..e677b5451f82 100644 --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -140,6 +140,12 @@ * be freed, plus any delayed work we may not have gotten rid of in the case * of metadata. * + * FORCE_COMMIT_TRANS + * For use by the preemptive flusher. We use this to bypass the ticketing + * checks in may_commit_transaction, as we have more information about the + * overall state of the system and may want to commit the transaction ahead + * of actual ENOSPC conditions. + * * OVERCOMMIT * * Because we hold so many reservations for metadata we will allow you to @@ -735,6 +741,14 @@ static void flush_space(struct btrfs_fs_info *fs_info, case COMMIT_TRANS: ret = may_commit_transaction(fs_info, space_info); break; + case FORCE_COMMIT_TRANS: + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + ret = btrfs_commit_transaction(trans); + break; default: ret = -ENOSPC; break; diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h index b0ea2a108be3..8a7c163907a2 100644 --- a/include/trace/events/btrfs.h +++ b/include/trace/events/btrfs.h @@ -99,7 +99,8 @@ struct btrfs_space_info; EM( ALLOC_CHUNK, "ALLOC_CHUNK") \ EM( ALLOC_CHUNK_FORCE, "ALLOC_CHUNK_FORCE") \ EM( RUN_DELAYED_IPUTS, "RUN_DELAYED_IPUTS") \ - EMe(COMMIT_TRANS, "COMMIT_TRANS") + EM( COMMIT_TRANS, "COMMIT_TRANS") \ + EMe(FORCE_COMMIT_TRANS, "FORCE_COMMIT_TRANS") /* * First define the enums in the above macros to be exported to userspace via