On Wed, Oct 09, 2019 at 04:27:47PM +0200, Christoph Hellwig wrote:
> ic_state really is a set of different states, even if the values are
> encoded as non-conflicting bits and we sometimes use logical and
> operations to check for them. Switch all comparisms to check for
> exact values (and use switch statements in a few places to make it
> more clear) and turn the values into an implicitly enumerated enum
> type.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> fs/xfs/xfs_log.c | 159 ++++++++++++++++++++----------------------
> fs/xfs/xfs_log_cil.c | 2 +-
> fs/xfs/xfs_log_priv.h | 21 +++---
> 3 files changed, 88 insertions(+), 94 deletions(-)
>
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index 7a429e5dc27c..001a9586cb56 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -584,7 +584,7 @@ xlog_state_release_iclog(
> {
> lockdep_assert_held(&log->l_icloglock);
>
> - if (iclog->ic_state & XLOG_STATE_IOERROR)
> + if (iclog->ic_state == XLOG_STATE_IOERROR)
> return -EIO;
>
> if (atomic_dec_and_test(&iclog->ic_refcnt) &&
> @@ -605,7 +605,7 @@ xfs_log_release_iclog(
> struct xlog *log = mp->m_log;
> bool sync;
>
> - if (iclog->ic_state & XLOG_STATE_IOERROR) {
> + if (iclog->ic_state == XLOG_STATE_IOERROR) {
> xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
> return -EIO;
> }
> @@ -975,8 +975,8 @@ xfs_log_unmount_write(xfs_mount_t *mp)
> #ifdef DEBUG
> first_iclog = iclog = log->l_iclog;
> do {
> - if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
> - ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE);
> + if (iclog->ic_state != XLOG_STATE_IOERROR) {
> + ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
> ASSERT(iclog->ic_offset == 0);
> }
> iclog = iclog->ic_next;
> @@ -1003,15 +1003,15 @@ xfs_log_unmount_write(xfs_mount_t *mp)
> atomic_inc(&iclog->ic_refcnt);
> xlog_state_want_sync(log, iclog);
> error = xlog_state_release_iclog(log, iclog);
> -
> - if ( ! ( iclog->ic_state == XLOG_STATE_ACTIVE
> - || iclog->ic_state == XLOG_STATE_DIRTY
> - || iclog->ic_state == XLOG_STATE_IOERROR) ) {
> -
> - xlog_wait(&iclog->ic_force_wait,
> - &log->l_icloglock);
> - } else {
> + switch (iclog->ic_state) {
> + case XLOG_STATE_ACTIVE:
> + case XLOG_STATE_DIRTY:
> + case XLOG_STATE_IOERROR:
> spin_unlock(&log->l_icloglock);
> + break;
> + default:
> + xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
> + break;
> }
> }
>
> @@ -1301,7 +1301,7 @@ xlog_ioend_work(
> * didn't succeed.
> */
> aborted = true;
> - } else if (iclog->ic_state & XLOG_STATE_IOERROR) {
> + } else if (iclog->ic_state == XLOG_STATE_IOERROR) {
> aborted = true;
> }
>
> @@ -1774,7 +1774,7 @@ xlog_write_iclog(
> * across the log IO to archieve that.
> */
> down(&iclog->ic_sema);
> - if (unlikely(iclog->ic_state & XLOG_STATE_IOERROR)) {
> + if (unlikely(iclog->ic_state == XLOG_STATE_IOERROR)) {
> /*
> * It would seem logical to return EIO here, but we rely on
> * the log state machine to propagate I/O errors instead of
> @@ -2598,7 +2598,7 @@ xlog_state_clean_iclog(
> int changed = 0;
>
> /* Prepare the completed iclog. */
> - if (!(dirty_iclog->ic_state & XLOG_STATE_IOERROR))
> + if (dirty_iclog->ic_state != XLOG_STATE_IOERROR)
> dirty_iclog->ic_state = XLOG_STATE_DIRTY;
>
> /* Walk all the iclogs to update the ordered active state. */
> @@ -2689,7 +2689,8 @@ xlog_get_lowest_lsn(
> xfs_lsn_t lowest_lsn = 0, lsn;
>
> do {
> - if (iclog->ic_state & (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY))
> + if (iclog->ic_state == XLOG_STATE_ACTIVE ||
> + iclog->ic_state == XLOG_STATE_DIRTY)
> continue;
>
> lsn = be64_to_cpu(iclog->ic_header.h_lsn);
> @@ -2755,55 +2756,50 @@ xlog_state_iodone_process_iclog(
> xfs_lsn_t lowest_lsn;
> xfs_lsn_t header_lsn;
>
> - /* Skip all iclogs in the ACTIVE & DIRTY states */
> - if (iclog->ic_state & (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY))
> + switch (iclog->ic_state) {
> + case XLOG_STATE_ACTIVE:
> + case XLOG_STATE_DIRTY:
> + /*
> + * Skip all iclogs in the ACTIVE & DIRTY states:
> + */
> return false;
> -
> - /*
> - * Between marking a filesystem SHUTDOWN and stopping the log, we do
> - * flush all iclogs to disk (if there wasn't a log I/O error). So, we do
> - * want things to go smoothly in case of just a SHUTDOWN w/o a
> - * LOG_IO_ERROR.
> - */
> - if (iclog->ic_state & XLOG_STATE_IOERROR) {
> + case XLOG_STATE_IOERROR:
> + /*
> + * Between marking a filesystem SHUTDOWN and stopping the log,
> + * we do flush all iclogs to disk (if there wasn't a log I/O
> + * error). So, we do want things to go smoothly in case of just
> + * a SHUTDOWN w/o a LOG_IO_ERROR.
> + */
> *ioerror = true;
> return false;
> - }
> -
> - /*
> - * Can only perform callbacks in order. Since this iclog is not in the
> - * DONE_SYNC/ DO_CALLBACK state, we skip the rest and just try to clean
> - * up. If we set our iclog to DO_CALLBACK, we will not process it when
> - * we retry since a previous iclog is in the CALLBACK and the state
> - * cannot change since we are holding the l_icloglock.
> - */
> - if (!(iclog->ic_state &
> - (XLOG_STATE_DONE_SYNC | XLOG_STATE_DO_CALLBACK))) {
> + case XLOG_STATE_DONE_SYNC:
> + case XLOG_STATE_DO_CALLBACK:
> + /*
> + * Now that we have an iclog that is in either the DO_CALLBACK
> + * or DONE_SYNC states, do one more check here to see if we have
> + * chased our tail around. If this is not the lowest lsn iclog,
> + * then we will leave it for another completion to process.
> + */
> + header_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
> + lowest_lsn = xlog_get_lowest_lsn(log);
> + if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, header_lsn) < 0)
> + return false;
> + xlog_state_set_callback(log, iclog, header_lsn);
> + return false;
> + default:
> + /*
> + * Can only perform callbacks in order. Since this iclog is not
> + * in the DONE_SYNC or DO_CALLBACK states, we skip the rest and
> + * just try to clean up. If we set our iclog to DO_CALLBACK, we
> + * will not process it when we retry since a previous iclog is
> + * in the CALLBACK and the state cannot change since we are
> + * holding l_icloglock.
> + */
> if (completed_iclog &&
> - (completed_iclog->ic_state == XLOG_STATE_DONE_SYNC)) {
> + (completed_iclog->ic_state == XLOG_STATE_DONE_SYNC))
> completed_iclog->ic_state = XLOG_STATE_DO_CALLBACK;
> - }
> return true;
> }
> -
> - /*
> - * We now have an iclog that is in either the DO_CALLBACK or DONE_SYNC
> - * states. The other states (WANT_SYNC, SYNCING, or CALLBACK were caught
> - * by the above if and are going to clean (i.e. we aren't doing their
> - * callbacks) see the above if.
> - *
> - * We will do one more check here to see if we have chased our tail
> - * around. If this is not the lowest lsn iclog, then we will leave it
> - * for another completion to process.
> - */
> - header_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
> - lowest_lsn = xlog_get_lowest_lsn(log);
> - if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, header_lsn) < 0)
> - return false;
> -
> - xlog_state_set_callback(log, iclog, header_lsn);
> - return false;
> -
> }
>
> /*
> @@ -2850,9 +2846,6 @@ xlog_state_do_iclog_callbacks(
> * are deferred to the completion of the earlier iclog. Walk the iclogs in order
> * and make sure that no iclog is in DO_CALLBACK unless an earlier iclog is in
> * one of the syncing states.
> - *
> - * Note that SYNCING|IOERROR is a valid state so we cannot just check for
> - * ic_state == SYNCING.
> */
> static void
> xlog_state_callback_check_state(
> @@ -2873,7 +2866,7 @@ xlog_state_callback_check_state(
> * IOERROR - give up hope all ye who enter here
> */
> if (iclog->ic_state == XLOG_STATE_WANT_SYNC ||
> - iclog->ic_state & XLOG_STATE_SYNCING ||
> + iclog->ic_state == XLOG_STATE_SYNCING ||
> iclog->ic_state == XLOG_STATE_DONE_SYNC ||
> iclog->ic_state == XLOG_STATE_IOERROR )
> break;
> @@ -2919,8 +2912,8 @@ xlog_state_do_callback(
> ciclog, &ioerror))
> break;
>
> - if (!(iclog->ic_state &
> - (XLOG_STATE_CALLBACK | XLOG_STATE_IOERROR))) {
> + if (iclog->ic_state != XLOG_STATE_CALLBACK &&
> + iclog->ic_state != XLOG_STATE_IOERROR) {
> iclog = iclog->ic_next;
> continue;
> }
> @@ -2950,7 +2943,8 @@ xlog_state_do_callback(
> if (did_callbacks)
> xlog_state_callback_check_state(log);
>
> - if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR))
> + if (log->l_iclog->ic_state == XLOG_STATE_ACTIVE ||
> + log->l_iclog->ic_state == XLOG_STATE_IOERROR)
> wake_up_all(&log->l_flush_wait);
>
> spin_unlock(&log->l_icloglock);
> @@ -2979,8 +2973,6 @@ xlog_state_done_syncing(
>
> spin_lock(&log->l_icloglock);
>
> - ASSERT(iclog->ic_state == XLOG_STATE_SYNCING ||
> - iclog->ic_state == XLOG_STATE_IOERROR);
> ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
>
> /*
> @@ -2989,8 +2981,10 @@ xlog_state_done_syncing(
> * and none should ever be attempted to be written to disk
> * again.
> */
> - if (iclog->ic_state != XLOG_STATE_IOERROR)
> + if (iclog->ic_state == XLOG_STATE_SYNCING)
> iclog->ic_state = XLOG_STATE_DONE_SYNC;
> + else
> + ASSERT(iclog->ic_state == XLOG_STATE_IOERROR);
>
> /*
> * Someone could be sleeping prior to writing out the next
> @@ -3300,7 +3294,7 @@ xfs_log_force(
>
> spin_lock(&log->l_icloglock);
> iclog = log->l_iclog;
> - if (iclog->ic_state & XLOG_STATE_IOERROR)
> + if (iclog->ic_state == XLOG_STATE_IOERROR)
> goto out_error;
>
> if (iclog->ic_state == XLOG_STATE_DIRTY ||
> @@ -3357,11 +3351,11 @@ xfs_log_force(
> if (!(flags & XFS_LOG_SYNC))
> goto out_unlock;
>
> - if (iclog->ic_state & XLOG_STATE_IOERROR)
> + if (iclog->ic_state == XLOG_STATE_IOERROR)
> goto out_error;
> XFS_STATS_INC(mp, xs_log_force_sleep);
> xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
> - if (iclog->ic_state & XLOG_STATE_IOERROR)
> + if (iclog->ic_state == XLOG_STATE_IOERROR)
> return -EIO;
> return 0;
>
> @@ -3386,7 +3380,7 @@ __xfs_log_force_lsn(
>
> spin_lock(&log->l_icloglock);
> iclog = log->l_iclog;
> - if (iclog->ic_state & XLOG_STATE_IOERROR)
> + if (iclog->ic_state == XLOG_STATE_IOERROR)
> goto out_error;
>
> while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
> @@ -3415,10 +3409,8 @@ __xfs_log_force_lsn(
> * will go out then.
> */
> if (!already_slept &&
> - (iclog->ic_prev->ic_state &
> - (XLOG_STATE_WANT_SYNC | XLOG_STATE_SYNCING))) {
> - ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR));
> -
> + (iclog->ic_prev->ic_state == XLOG_STATE_WANT_SYNC ||
> + iclog->ic_prev->ic_state == XLOG_STATE_SYNCING)) {
> XFS_STATS_INC(mp, xs_log_force_sleep);
>
> xlog_wait(&iclog->ic_prev->ic_write_wait,
> @@ -3434,15 +3426,16 @@ __xfs_log_force_lsn(
> }
>
> if (!(flags & XFS_LOG_SYNC) ||
> - (iclog->ic_state & (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY)))
> + (iclog->ic_state == XLOG_STATE_ACTIVE ||
> + iclog->ic_state == XLOG_STATE_DIRTY))
> goto out_unlock;
>
> - if (iclog->ic_state & XLOG_STATE_IOERROR)
> + if (iclog->ic_state == XLOG_STATE_IOERROR)
> goto out_error;
>
> XFS_STATS_INC(mp, xs_log_force_sleep);
> xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
> - if (iclog->ic_state & XLOG_STATE_IOERROR)
> + if (iclog->ic_state == XLOG_STATE_IOERROR)
> return -EIO;
> return 0;
>
> @@ -3505,8 +3498,8 @@ xlog_state_want_sync(
> if (iclog->ic_state == XLOG_STATE_ACTIVE) {
> xlog_state_switch_iclogs(log, iclog, 0);
> } else {
> - ASSERT(iclog->ic_state &
> - (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR));
> + ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC ||
> + iclog->ic_state == XLOG_STATE_IOERROR);
> }
> }
>
> @@ -3883,7 +3876,7 @@ xlog_state_ioerror(
> xlog_in_core_t *iclog, *ic;
>
> iclog = log->l_iclog;
> - if (! (iclog->ic_state & XLOG_STATE_IOERROR)) {
> + if (iclog->ic_state != XLOG_STATE_IOERROR) {
> /*
> * Mark all the incore logs IOERROR.
> * From now on, no log flushes will result.
> @@ -3943,7 +3936,7 @@ xfs_log_force_umount(
> * Somebody could've already done the hard work for us.
> * No need to get locks for this.
> */
> - if (logerror && log->l_iclog->ic_state & XLOG_STATE_IOERROR) {
> + if (logerror && log->l_iclog->ic_state == XLOG_STATE_IOERROR) {
> ASSERT(XLOG_FORCED_SHUTDOWN(log));
> return 1;
> }
> diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
> index ef652abd112c..a1204424a938 100644
> --- a/fs/xfs/xfs_log_cil.c
> +++ b/fs/xfs/xfs_log_cil.c
> @@ -847,7 +847,7 @@ xlog_cil_push(
> goto out_abort;
>
> spin_lock(&commit_iclog->ic_callback_lock);
> - if (commit_iclog->ic_state & XLOG_STATE_IOERROR) {
> + if (commit_iclog->ic_state == XLOG_STATE_IOERROR) {
> spin_unlock(&commit_iclog->ic_callback_lock);
> goto out_abort;
> }
> diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
> index 66bd370ae60a..bf076893f516 100644
> --- a/fs/xfs/xfs_log_priv.h
> +++ b/fs/xfs/xfs_log_priv.h
> @@ -40,15 +40,16 @@ static inline uint xlog_get_client_id(__be32 i)
> /*
> * In core log state
> */
> -#define XLOG_STATE_ACTIVE 0x0001 /* Current IC log being written to */
> -#define XLOG_STATE_WANT_SYNC 0x0002 /* Want to sync this iclog; no more writes */
> -#define XLOG_STATE_SYNCING 0x0004 /* This IC log is syncing */
> -#define XLOG_STATE_DONE_SYNC 0x0008 /* Done syncing to disk */
> -#define XLOG_STATE_DO_CALLBACK \
> - 0x0010 /* Process callback functions */
> -#define XLOG_STATE_CALLBACK 0x0020 /* Callback functions now */
> -#define XLOG_STATE_DIRTY 0x0040 /* Dirty IC log, not ready for ACTIVE status*/
> -#define XLOG_STATE_IOERROR 0x0080 /* IO error happened in sync'ing log */
> +enum xlog_iclog_state {
> + XLOG_STATE_ACTIVE, /* Current IC log being written to */
> + XLOG_STATE_WANT_SYNC, /* Want to sync this iclog; no more writes */
> + XLOG_STATE_SYNCING, /* This IC log is syncing */
> + XLOG_STATE_DONE_SYNC, /* Done syncing to disk */
> + XLOG_STATE_DO_CALLBACK, /* Process callback functions */
> + XLOG_STATE_CALLBACK, /* Callback functions now */
> + XLOG_STATE_DIRTY, /* Dirty IC log, not ready for ACTIVE status */
> + XLOG_STATE_IOERROR, /* IO error happened in sync'ing log */
> +};
>
> /*
> * Flags to log ticket
> @@ -202,7 +203,7 @@ typedef struct xlog_in_core {
> struct xlog *ic_log;
> u32 ic_size;
> u32 ic_offset;
> - unsigned short ic_state;
> + enum xlog_iclog_state ic_state;
> char *ic_datap; /* pointer to iclog data */
>
> /* Callback structures need their own cacheline */
> --
> 2.20.1
>
