From d699ae4fc27496d01e8bc5ab2106bd79d1e7be92 Mon Sep 17 00:00:00 2001 From: Alexander Lochmann Date: Thu, 11 Feb 2021 10:51:55 +0100 Subject: [PATCH] ext4: updated locking documentation for journal_t Some members of transaction_t are allowed to be read without any lock being held if consistency doesn't matter. Based on LockDoc's findings, we extended the locking documentation of those members. Each one of them is marked with a short comment: "no lock for quick racy checks". Signed-off-by: Alexander Lochmann Signed-off-by: Horst Schirmeier Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/ad82c7a9-a624-4ed5-5ada-a6410c44c0b3@tu-dortmund.de Signed-off-by: Theodore Ts'o --- include/linux/jbd2.h | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 99d3cd0..74710bb 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -768,7 +768,8 @@ enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY}; struct journal_s { /** - * @j_flags: General journaling state flags [j_state_lock] + * @j_flags: General journaling state flags [j_state_lock, + * no lock for quick racy checks] */ unsigned long j_flags; @@ -808,7 +809,8 @@ struct journal_s /** * @j_barrier_count: * - * Number of processes waiting to create a barrier lock [j_state_lock] + * Number of processes waiting to create a barrier lock [j_state_lock, + * no lock for quick racy checks] */ int j_barrier_count; @@ -821,7 +823,8 @@ struct journal_s * @j_running_transaction: * * Transactions: The current running transaction... - * [j_state_lock] [caller holding open handle] + * [j_state_lock, no lock for quick racy checks] [caller holding + * open handle] */ transaction_t *j_running_transaction; @@ -1033,7 +1036,7 @@ struct journal_s * @j_commit_sequence: * * Sequence number of the most recently committed transaction - * [j_state_lock]. + * [j_state_lock, no lock for quick racy checks] */ tid_t j_commit_sequence; @@ -1041,7 +1044,7 @@ struct journal_s * @j_commit_request: * * Sequence number of the most recent transaction wanting commit - * [j_state_lock] + * [j_state_lock, no lock for quick racy checks] */ tid_t j_commit_request; -- 2.7.4