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authorJosef Bacik <josef@toxicpanda.com>2021-06-22 15:51:58 +0300
committerDavid Sterba <dsterba@suse.com>2021-06-22 15:50:45 +0300
commitc416a30cddec0840520e9ffb170aea6c6b6c64af (patch)
tree4723335c03b1fad950fe9bcf30e0f59f0ed61901 /include/trace
parent35b22c19afe71c37540c0e4b574a441d27b03853 (diff)
downloadlinux-c416a30cddec0840520e9ffb170aea6c6b6c64af.tar.xz
btrfs: rip out may_commit_transaction
may_commit_transaction was introduced before the ticketing infrastructure existed. There was a problem where we'd legitimately be out of space, but every reservation would trigger a transaction commit and then fail. Thus if you had 1000 things trying to make a reservation, they'd all do the flushing loop and thus commit the transaction 1000 times before they'd get their ENOSPC. This helper was introduced to short circuit this, if there wasn't space that could be reclaimed by committing the transaction then simply ENOSPC out. This made true ENOSPC tests much faster as we didn't waste a bunch of time. However many of our bugs over the years have been from cases where we didn't account for some space that would be reclaimed by committing a transaction. The delayed refs rsv space, delayed rsv, many pinned bytes miscalculations, etc. And in the meantime the original problem has been solved with ticketing. We no longer will commit the transaction 1000 times. Instead we'll get 1000 waiters, we will go through the flushing mechanisms, and if there's no progress after 2 loops we ENOSPC everybody out. The ticketing infrastructure gives us a deterministic way to see if we're making progress or not, thus we avoid a lot of extra work. So simplify this step by simply unconditionally committing the transaction. This removes what is arguably our most common source of early ENOSPC bugs and will allow us to drastically simplify many of the things we track because we simply won't need them with this stuff gone. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'include/trace')
-rw-r--r--include/trace/events/btrfs.h3
1 files changed, 1 insertions, 2 deletions
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 76e0be7e14d0..c7237317a8b9 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -99,8 +99,7 @@ struct btrfs_space_info;
EM( ALLOC_CHUNK, "ALLOC_CHUNK") \
EM( ALLOC_CHUNK_FORCE, "ALLOC_CHUNK_FORCE") \
EM( RUN_DELAYED_IPUTS, "RUN_DELAYED_IPUTS") \
- EM( COMMIT_TRANS, "COMMIT_TRANS") \
- EMe(FORCE_COMMIT_TRANS, "FORCE_COMMIT_TRANS")
+ EMe(COMMIT_TRANS, "COMMIT_TRANS")
/*
* First define the enums in the above macros to be exported to userspace via