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| author | Darrick J. Wong <djwong@kernel.org> | 2021-08-08 18:27:12 +0300 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2021-08-10 01:57:59 +0300 |
| commit | 2b73a2c817be58de2190940dbfa38dbf8a3806e6 (patch) | |
| tree | 68df03ee93057b05952770f03cd2581a2da0ebc2 /fs/xfs/xfs_log_priv.h | |
| parent | 908ce71e54f8265fa909200410d6c50ab9a2d302 (diff) | |
| download | linux-2b73a2c817be58de2190940dbfa38dbf8a3806e6.tar.xz | |
xfs: clear log incompat feature bits when the log is idle
When there are no ongoing transactions and the log contents have been
checkpointed back into the filesystem, the log performs 'covering',
which is to say that it log a dummy transaction to record the fact that
the tail has caught up with the head. This is a good time to clear log
incompat feature flags, because they are flags that are temporarily set
to limit the range of kernels that can replay a dirty log.
Since it's possible that some other higher level thread is about to
start logging items protected by a log incompat flag, we create a rwsem
so that upper level threads can coordinate this with the log. It would
probably be more performant to use a percpu rwsem, but the ability to
/try/ taking the write lock during covering is critical, and percpu
rwsems do not provide that.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Diffstat (limited to 'fs/xfs/xfs_log_priv.h')
| -rw-r--r-- | fs/xfs/xfs_log_priv.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index f3e79a45d60a..6953f86f866c 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -456,6 +456,9 @@ struct xlog { xfs_lsn_t l_recovery_lsn; uint32_t l_iclog_roundoff;/* padding roundoff */ + + /* Users of log incompat features should take a read lock. */ + struct rw_semaphore l_incompat_users; }; #define XLOG_BUF_CANCEL_BUCKET(log, blkno) \ |