| Message ID | 20200316144233.900390-7-hch@lst.de (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [01/14] xfs: merge xlog_cil_push into xlog_cil_push_work | expand |
On Mon, Mar 16, 2020 at 03:42:25PM +0100, Christoph Hellwig wrote: > Factor out a few self-container helper from xlog_state_clean_iclog, and "self-contained" ? > update the documentation so it primarily documents why things happens > instead of how. > > Signed-off-by: Christoph Hellwig <hch@lst.de> Looks ok otherwise, I think I saw where all the pieces landed :) Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > --- > fs/xfs/xfs_log.c | 180 +++++++++++++++++++++++------------------------ > 1 file changed, 87 insertions(+), 93 deletions(-) > > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > index 8ede2852f104..23979d08a2a3 100644 > --- a/fs/xfs/xfs_log.c > +++ b/fs/xfs/xfs_log.c > @@ -2540,112 +2540,106 @@ xlog_write( > ***************************************************************************** > */ > > +static void > +xlog_state_activate_iclog( > + struct xlog_in_core *iclog, > + int *iclogs_changed) > +{ > + ASSERT(list_empty_careful(&iclog->ic_callbacks)); > + > + /* > + * If the number of ops in this iclog indicate it just contains the > + * dummy transaction, we can change state into IDLE (the second time > + * around). Otherwise we should change the state into NEED a dummy. > + * We don't need to cover the dummy. > + */ > + if (*iclogs_changed == 0 && > + iclog->ic_header.h_num_logops == cpu_to_be32(XLOG_COVER_OPS)) { > + *iclogs_changed = 1; > + } else { > + /* > + * We have two dirty iclogs so start over. This could also be > + * num of ops indicating this is not the dummy going out. > + */ > + *iclogs_changed = 2; > + } > + > + iclog->ic_state = XLOG_STATE_ACTIVE; > + iclog->ic_offset = 0; > + iclog->ic_header.h_num_logops = 0; > + memset(iclog->ic_header.h_cycle_data, 0, > + sizeof(iclog->ic_header.h_cycle_data)); > + iclog->ic_header.h_lsn = 0; > +} > + > /* > - * An iclog has just finished IO completion processing, so we need to update > - * the iclog state and propagate that up into the overall log state. Hence we > - * prepare the iclog for cleaning, and then clean all the pending dirty iclogs > - * starting from the head, and then wake up any threads that are waiting for the > - * iclog to be marked clean. > - * > - * The ordering of marking iclogs ACTIVE must be maintained, so an iclog > - * doesn't become ACTIVE beyond one that is SYNCING. This is also required to > - * maintain the notion that we use a ordered wait queue to hold off would be > - * writers to the log when every iclog is trying to sync to disk. > - * > - * Caller must hold the icloglock before calling us. > - * > - * State Change: !IOERROR -> DIRTY -> ACTIVE > + * Loop through all iclogs and mark all iclogs currently marked DIRTY as > + * ACTIVE after iclog I/O has completed. > */ > -STATIC void > -xlog_state_clean_iclog( > +static void > +xlog_state_activate_iclogs( > struct xlog *log, > - struct xlog_in_core *dirty_iclog) > + int *iclogs_changed) > { > - struct xlog_in_core *iclog; > - int changed = 0; > - > - /* Prepare the completed iclog. */ > - if (dirty_iclog->ic_state != XLOG_STATE_IOERROR) > - dirty_iclog->ic_state = XLOG_STATE_DIRTY; > + struct xlog_in_core *iclog = log->l_iclog; > > - /* Walk all the iclogs to update the ordered active state. */ > - iclog = log->l_iclog; > do { > - if (iclog->ic_state == XLOG_STATE_DIRTY) { > - iclog->ic_state = XLOG_STATE_ACTIVE; > - iclog->ic_offset = 0; > - ASSERT(list_empty_careful(&iclog->ic_callbacks)); > - /* > - * If the number of ops in this iclog indicate it just > - * contains the dummy transaction, we can > - * change state into IDLE (the second time around). > - * Otherwise we should change the state into > - * NEED a dummy. > - * We don't need to cover the dummy. > - */ > - if (!changed && > - (be32_to_cpu(iclog->ic_header.h_num_logops) == > - XLOG_COVER_OPS)) { > - changed = 1; > - } else { > - /* > - * We have two dirty iclogs so start over > - * This could also be num of ops indicates > - * this is not the dummy going out. > - */ > - changed = 2; > - } > - iclog->ic_header.h_num_logops = 0; > - memset(iclog->ic_header.h_cycle_data, 0, > - sizeof(iclog->ic_header.h_cycle_data)); > - iclog->ic_header.h_lsn = 0; > - } else if (iclog->ic_state == XLOG_STATE_ACTIVE) > - /* do nothing */; > - else > - break; /* stop cleaning */ > - iclog = iclog->ic_next; > - } while (iclog != log->l_iclog); > - > + if (iclog->ic_state == XLOG_STATE_DIRTY) > + xlog_state_activate_iclog(iclog, iclogs_changed); > + /* > + * The ordering of marking iclogs ACTIVE must be maintained, so > + * an iclog doesn't become ACTIVE beyond one that is SYNCING. > + */ > + else if (iclog->ic_state != XLOG_STATE_ACTIVE) > + break; > + } while ((iclog = iclog->ic_next) != log->l_iclog); > +} > > +static int > +xlog_covered_state( > + struct xlog *log, > + int iclogs_changed) > +{ > /* > - * Wake up threads waiting in xfs_log_force() for the dirty iclog > - * to be cleaned. > + * We usually go to NEED. But we go to NEED2 if the changed indicates we > + * are done writing the dummy record. If we are done with the second > + * dummy recored (DONE2), then we go to IDLE. > */ > - wake_up_all(&dirty_iclog->ic_force_wait); > + switch (log->l_covered_state) { > + case XLOG_STATE_COVER_IDLE: > + case XLOG_STATE_COVER_NEED: > + case XLOG_STATE_COVER_NEED2: > + break; > + case XLOG_STATE_COVER_DONE: > + if (iclogs_changed == 1) > + return XLOG_STATE_COVER_NEED2; > + break; > + case XLOG_STATE_COVER_DONE2: > + if (iclogs_changed == 1) > + return XLOG_STATE_COVER_IDLE; > + break; > + default: > + ASSERT(0); > + } > > - /* > - * Change state for the dummy log recording. > - * We usually go to NEED. But we go to NEED2 if the changed indicates > - * we are done writing the dummy record. > - * If we are done with the second dummy recored (DONE2), then > - * we go to IDLE. > - */ > - if (changed) { > - switch (log->l_covered_state) { > - case XLOG_STATE_COVER_IDLE: > - case XLOG_STATE_COVER_NEED: > - case XLOG_STATE_COVER_NEED2: > - log->l_covered_state = XLOG_STATE_COVER_NEED; > - break; > + return XLOG_STATE_COVER_NEED; > +} > > - case XLOG_STATE_COVER_DONE: > - if (changed == 1) > - log->l_covered_state = XLOG_STATE_COVER_NEED2; > - else > - log->l_covered_state = XLOG_STATE_COVER_NEED; > - break; > +STATIC void > +xlog_state_clean_iclog( > + struct xlog *log, > + struct xlog_in_core *dirty_iclog) > +{ > + int iclogs_changed = 0; > > - case XLOG_STATE_COVER_DONE2: > - if (changed == 1) > - log->l_covered_state = XLOG_STATE_COVER_IDLE; > - else > - log->l_covered_state = XLOG_STATE_COVER_NEED; > - break; > + if (dirty_iclog->ic_state != XLOG_STATE_IOERROR) > + dirty_iclog->ic_state = XLOG_STATE_DIRTY; > > - default: > - ASSERT(0); > - } > - } > + xlog_state_activate_iclogs(log, &iclogs_changed); > + wake_up_all(&dirty_iclog->ic_force_wait); > + > + if (iclogs_changed) > + log->l_covered_state = xlog_covered_state(log, iclogs_changed); > } > > STATIC xfs_lsn_t > -- > 2.24.1 >
On Mon, Mar 16, 2020 at 03:42:25PM +0100, Christoph Hellwig wrote: > Factor out a few self-container helper from xlog_state_clean_iclog, and > update the documentation so it primarily documents why things happens > instead of how. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > fs/xfs/xfs_log.c | 180 +++++++++++++++++++++++------------------------ > 1 file changed, 87 insertions(+), 93 deletions(-) > > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > index 8ede2852f104..23979d08a2a3 100644 > --- a/fs/xfs/xfs_log.c > +++ b/fs/xfs/xfs_log.c > @@ -2540,112 +2540,106 @@ xlog_write( ... > +static int > +xlog_covered_state( > + struct xlog *log, > + int iclogs_changed) > +{ > /* > - * Wake up threads waiting in xfs_log_force() for the dirty iclog > - * to be cleaned. > + * We usually go to NEED. But we go to NEED2 if the changed indicates we > + * are done writing the dummy record. If we are done with the second > + * dummy recored (DONE2), then we go to IDLE. > */ > - wake_up_all(&dirty_iclog->ic_force_wait); > + switch (log->l_covered_state) { > + case XLOG_STATE_COVER_IDLE: > + case XLOG_STATE_COVER_NEED: > + case XLOG_STATE_COVER_NEED2: > + break; > + case XLOG_STATE_COVER_DONE: > + if (iclogs_changed == 1) > + return XLOG_STATE_COVER_NEED2; > + break; > + case XLOG_STATE_COVER_DONE2: > + if (iclogs_changed == 1) > + return XLOG_STATE_COVER_IDLE; > + break; > + default: > + ASSERT(0); > + } The code looks mostly fine, but I'm not a fan of this factoring where we deref ->l_covered_state here and return a value only for the caller to assign it to ->l_covered_state again. Can we just let this function assign ->l_covered_state itself (i.e. assign a local variable rather than return within the switch)? Brian > > - /* > - * Change state for the dummy log recording. > - * We usually go to NEED. But we go to NEED2 if the changed indicates > - * we are done writing the dummy record. > - * If we are done with the second dummy recored (DONE2), then > - * we go to IDLE. > - */ > - if (changed) { > - switch (log->l_covered_state) { > - case XLOG_STATE_COVER_IDLE: > - case XLOG_STATE_COVER_NEED: > - case XLOG_STATE_COVER_NEED2: > - log->l_covered_state = XLOG_STATE_COVER_NEED; > - break; > + return XLOG_STATE_COVER_NEED; > +} > > - case XLOG_STATE_COVER_DONE: > - if (changed == 1) > - log->l_covered_state = XLOG_STATE_COVER_NEED2; > - else > - log->l_covered_state = XLOG_STATE_COVER_NEED; > - break; > +STATIC void > +xlog_state_clean_iclog( > + struct xlog *log, > + struct xlog_in_core *dirty_iclog) > +{ > + int iclogs_changed = 0; > > - case XLOG_STATE_COVER_DONE2: > - if (changed == 1) > - log->l_covered_state = XLOG_STATE_COVER_IDLE; > - else > - log->l_covered_state = XLOG_STATE_COVER_NEED; > - break; > + if (dirty_iclog->ic_state != XLOG_STATE_IOERROR) > + dirty_iclog->ic_state = XLOG_STATE_DIRTY; > > - default: > - ASSERT(0); > - } > - } > + xlog_state_activate_iclogs(log, &iclogs_changed); > + wake_up_all(&dirty_iclog->ic_force_wait); > + > + if (iclogs_changed) > + log->l_covered_state = xlog_covered_state(log, iclogs_changed); > } > > STATIC xfs_lsn_t > -- > 2.24.1 >
On Tue, Mar 17, 2020 at 09:25:05AM -0400, Brian Foster wrote: > The code looks mostly fine, but I'm not a fan of this factoring where we > deref ->l_covered_state here and return a value only for the caller to > assign it to ->l_covered_state again. Can we just let this function > assign ->l_covered_state itself (i.e. assign a local variable rather than > return within the switch)? I did that earlier, but this version looked easier to understand to me. I can change it if there is a strong preference.
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 8ede2852f104..23979d08a2a3 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -2540,112 +2540,106 @@ xlog_write( ***************************************************************************** */ +static void +xlog_state_activate_iclog( + struct xlog_in_core *iclog, + int *iclogs_changed) +{ + ASSERT(list_empty_careful(&iclog->ic_callbacks)); + + /* + * If the number of ops in this iclog indicate it just contains the + * dummy transaction, we can change state into IDLE (the second time + * around). Otherwise we should change the state into NEED a dummy. + * We don't need to cover the dummy. + */ + if (*iclogs_changed == 0 && + iclog->ic_header.h_num_logops == cpu_to_be32(XLOG_COVER_OPS)) { + *iclogs_changed = 1; + } else { + /* + * We have two dirty iclogs so start over. This could also be + * num of ops indicating this is not the dummy going out. + */ + *iclogs_changed = 2; + } + + iclog->ic_state = XLOG_STATE_ACTIVE; + iclog->ic_offset = 0; + iclog->ic_header.h_num_logops = 0; + memset(iclog->ic_header.h_cycle_data, 0, + sizeof(iclog->ic_header.h_cycle_data)); + iclog->ic_header.h_lsn = 0; +} + /* - * An iclog has just finished IO completion processing, so we need to update - * the iclog state and propagate that up into the overall log state. Hence we - * prepare the iclog for cleaning, and then clean all the pending dirty iclogs - * starting from the head, and then wake up any threads that are waiting for the - * iclog to be marked clean. - * - * The ordering of marking iclogs ACTIVE must be maintained, so an iclog - * doesn't become ACTIVE beyond one that is SYNCING. This is also required to - * maintain the notion that we use a ordered wait queue to hold off would be - * writers to the log when every iclog is trying to sync to disk. - * - * Caller must hold the icloglock before calling us. - * - * State Change: !IOERROR -> DIRTY -> ACTIVE + * Loop through all iclogs and mark all iclogs currently marked DIRTY as + * ACTIVE after iclog I/O has completed. */ -STATIC void -xlog_state_clean_iclog( +static void +xlog_state_activate_iclogs( struct xlog *log, - struct xlog_in_core *dirty_iclog) + int *iclogs_changed) { - struct xlog_in_core *iclog; - int changed = 0; - - /* Prepare the completed iclog. */ - if (dirty_iclog->ic_state != XLOG_STATE_IOERROR) - dirty_iclog->ic_state = XLOG_STATE_DIRTY; + struct xlog_in_core *iclog = log->l_iclog; - /* Walk all the iclogs to update the ordered active state. */ - iclog = log->l_iclog; do { - if (iclog->ic_state == XLOG_STATE_DIRTY) { - iclog->ic_state = XLOG_STATE_ACTIVE; - iclog->ic_offset = 0; - ASSERT(list_empty_careful(&iclog->ic_callbacks)); - /* - * If the number of ops in this iclog indicate it just - * contains the dummy transaction, we can - * change state into IDLE (the second time around). - * Otherwise we should change the state into - * NEED a dummy. - * We don't need to cover the dummy. - */ - if (!changed && - (be32_to_cpu(iclog->ic_header.h_num_logops) == - XLOG_COVER_OPS)) { - changed = 1; - } else { - /* - * We have two dirty iclogs so start over - * This could also be num of ops indicates - * this is not the dummy going out. - */ - changed = 2; - } - iclog->ic_header.h_num_logops = 0; - memset(iclog->ic_header.h_cycle_data, 0, - sizeof(iclog->ic_header.h_cycle_data)); - iclog->ic_header.h_lsn = 0; - } else if (iclog->ic_state == XLOG_STATE_ACTIVE) - /* do nothing */; - else - break; /* stop cleaning */ - iclog = iclog->ic_next; - } while (iclog != log->l_iclog); - + if (iclog->ic_state == XLOG_STATE_DIRTY) + xlog_state_activate_iclog(iclog, iclogs_changed); + /* + * The ordering of marking iclogs ACTIVE must be maintained, so + * an iclog doesn't become ACTIVE beyond one that is SYNCING. + */ + else if (iclog->ic_state != XLOG_STATE_ACTIVE) + break; + } while ((iclog = iclog->ic_next) != log->l_iclog); +} +static int +xlog_covered_state( + struct xlog *log, + int iclogs_changed) +{ /* - * Wake up threads waiting in xfs_log_force() for the dirty iclog - * to be cleaned. + * We usually go to NEED. But we go to NEED2 if the changed indicates we + * are done writing the dummy record. If we are done with the second + * dummy recored (DONE2), then we go to IDLE. */ - wake_up_all(&dirty_iclog->ic_force_wait); + switch (log->l_covered_state) { + case XLOG_STATE_COVER_IDLE: + case XLOG_STATE_COVER_NEED: + case XLOG_STATE_COVER_NEED2: + break; + case XLOG_STATE_COVER_DONE: + if (iclogs_changed == 1) + return XLOG_STATE_COVER_NEED2; + break; + case XLOG_STATE_COVER_DONE2: + if (iclogs_changed == 1) + return XLOG_STATE_COVER_IDLE; + break; + default: + ASSERT(0); + } - /* - * Change state for the dummy log recording. - * We usually go to NEED. But we go to NEED2 if the changed indicates - * we are done writing the dummy record. - * If we are done with the second dummy recored (DONE2), then - * we go to IDLE. - */ - if (changed) { - switch (log->l_covered_state) { - case XLOG_STATE_COVER_IDLE: - case XLOG_STATE_COVER_NEED: - case XLOG_STATE_COVER_NEED2: - log->l_covered_state = XLOG_STATE_COVER_NEED; - break; + return XLOG_STATE_COVER_NEED; +} - case XLOG_STATE_COVER_DONE: - if (changed == 1) - log->l_covered_state = XLOG_STATE_COVER_NEED2; - else - log->l_covered_state = XLOG_STATE_COVER_NEED; - break; +STATIC void +xlog_state_clean_iclog( + struct xlog *log, + struct xlog_in_core *dirty_iclog) +{ + int iclogs_changed = 0; - case XLOG_STATE_COVER_DONE2: - if (changed == 1) - log->l_covered_state = XLOG_STATE_COVER_IDLE; - else - log->l_covered_state = XLOG_STATE_COVER_NEED; - break; + if (dirty_iclog->ic_state != XLOG_STATE_IOERROR) + dirty_iclog->ic_state = XLOG_STATE_DIRTY; - default: - ASSERT(0); - } - } + xlog_state_activate_iclogs(log, &iclogs_changed); + wake_up_all(&dirty_iclog->ic_force_wait); + + if (iclogs_changed) + log->l_covered_state = xlog_covered_state(log, iclogs_changed); } STATIC xfs_lsn_t
Factor out a few self-container helper from xlog_state_clean_iclog, and update the documentation so it primarily documents why things happens instead of how. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/xfs/xfs_log.c | 180 +++++++++++++++++++++++------------------------ 1 file changed, 87 insertions(+), 93 deletions(-)