From 1054794198e39103cb986618c4c10ec2252b7089 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 21 Dec 2010 12:02:25 +1100 Subject: xfs: convert log grant ticket queues to list heads The grant write and reserve queues use a roll-your-own double linked list, so convert it to a standard list_head structure and convert all the list traversals to use list_for_each_entry(). We can also get rid of the XLOG_TIC_IN_Q flag as we can use the list_empty() check to tell if the ticket is in a list or not. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_log.c | 123 +++++++++++++++++++------------------------------------ 1 file changed, 41 insertions(+), 82 deletions(-) (limited to 'fs/xfs/xfs_log.c') diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index cee4ab9..1b82735 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -95,38 +95,6 @@ STATIC void xlog_verify_tail_lsn(xlog_t *log, xlog_in_core_t *iclog, STATIC int xlog_iclogs_empty(xlog_t *log); - -static void -xlog_ins_ticketq(struct xlog_ticket **qp, struct xlog_ticket *tic) -{ - if (*qp) { - tic->t_next = (*qp); - tic->t_prev = (*qp)->t_prev; - (*qp)->t_prev->t_next = tic; - (*qp)->t_prev = tic; - } else { - tic->t_prev = tic->t_next = tic; - *qp = tic; - } - - tic->t_flags |= XLOG_TIC_IN_Q; -} - -static void -xlog_del_ticketq(struct xlog_ticket **qp, struct xlog_ticket *tic) -{ - if (tic == tic->t_next) { - *qp = NULL; - } else { - *qp = tic->t_next; - tic->t_next->t_prev = tic->t_prev; - tic->t_prev->t_next = tic->t_next; - } - - tic->t_next = tic->t_prev = NULL; - tic->t_flags &= ~XLOG_TIC_IN_Q; -} - static void xlog_grant_sub_space(struct log *log, int bytes) { @@ -724,7 +692,7 @@ xfs_log_move_tail(xfs_mount_t *mp, log->l_tail_lsn = tail_lsn; } - if ((tic = log->l_write_headq)) { + if (!list_empty(&log->l_writeq)) { #ifdef DEBUG if (log->l_flags & XLOG_ACTIVE_RECOVERY) panic("Recovery problem"); @@ -732,7 +700,7 @@ xfs_log_move_tail(xfs_mount_t *mp, cycle = log->l_grant_write_cycle; bytes = log->l_grant_write_bytes; free_bytes = xlog_space_left(log, cycle, bytes); - do { + list_for_each_entry(tic, &log->l_writeq, t_queue) { ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV); if (free_bytes < tic->t_unit_res && tail_lsn != 1) @@ -740,10 +708,10 @@ xfs_log_move_tail(xfs_mount_t *mp, tail_lsn = 0; free_bytes -= tic->t_unit_res; sv_signal(&tic->t_wait); - tic = tic->t_next; - } while (tic != log->l_write_headq); + } } - if ((tic = log->l_reserve_headq)) { + + if (!list_empty(&log->l_reserveq)) { #ifdef DEBUG if (log->l_flags & XLOG_ACTIVE_RECOVERY) panic("Recovery problem"); @@ -751,7 +719,7 @@ xfs_log_move_tail(xfs_mount_t *mp, cycle = log->l_grant_reserve_cycle; bytes = log->l_grant_reserve_bytes; free_bytes = xlog_space_left(log, cycle, bytes); - do { + list_for_each_entry(tic, &log->l_reserveq, t_queue) { if (tic->t_flags & XLOG_TIC_PERM_RESERV) need_bytes = tic->t_unit_res*tic->t_cnt; else @@ -761,8 +729,7 @@ xfs_log_move_tail(xfs_mount_t *mp, tail_lsn = 0; free_bytes -= need_bytes; sv_signal(&tic->t_wait); - tic = tic->t_next; - } while (tic != log->l_reserve_headq); + } } spin_unlock(&log->l_grant_lock); } /* xfs_log_move_tail */ @@ -1053,6 +1020,8 @@ xlog_alloc_log(xfs_mount_t *mp, log->l_curr_cycle = 1; /* 0 is bad since this is initial value */ log->l_grant_reserve_cycle = 1; log->l_grant_write_cycle = 1; + INIT_LIST_HEAD(&log->l_reserveq); + INIT_LIST_HEAD(&log->l_writeq); error = EFSCORRUPTED; if (xfs_sb_version_hassector(&mp->m_sb)) { @@ -2550,8 +2519,8 @@ xlog_grant_log_space(xlog_t *log, trace_xfs_log_grant_enter(log, tic); /* something is already sleeping; insert new transaction at end */ - if (log->l_reserve_headq) { - xlog_ins_ticketq(&log->l_reserve_headq, tic); + if (!list_empty(&log->l_reserveq)) { + list_add_tail(&tic->t_queue, &log->l_reserveq); trace_xfs_log_grant_sleep1(log, tic); @@ -2583,8 +2552,8 @@ redo: free_bytes = xlog_space_left(log, log->l_grant_reserve_cycle, log->l_grant_reserve_bytes); if (free_bytes < need_bytes) { - if ((tic->t_flags & XLOG_TIC_IN_Q) == 0) - xlog_ins_ticketq(&log->l_reserve_headq, tic); + if (list_empty(&tic->t_queue)) + list_add_tail(&tic->t_queue, &log->l_reserveq); trace_xfs_log_grant_sleep2(log, tic); @@ -2602,8 +2571,9 @@ redo: trace_xfs_log_grant_wake2(log, tic); goto redo; - } else if (tic->t_flags & XLOG_TIC_IN_Q) - xlog_del_ticketq(&log->l_reserve_headq, tic); + } + + list_del_init(&tic->t_queue); /* we've got enough space */ xlog_grant_add_space(log, need_bytes); @@ -2626,9 +2596,7 @@ redo: return 0; error_return: - if (tic->t_flags & XLOG_TIC_IN_Q) - xlog_del_ticketq(&log->l_reserve_headq, tic); - + list_del_init(&tic->t_queue); trace_xfs_log_grant_error(log, tic); /* @@ -2653,7 +2621,6 @@ xlog_regrant_write_log_space(xlog_t *log, xlog_ticket_t *tic) { int free_bytes, need_bytes; - xlog_ticket_t *ntic; #ifdef DEBUG xfs_lsn_t tail_lsn; #endif @@ -2683,22 +2650,23 @@ xlog_regrant_write_log_space(xlog_t *log, * this transaction. */ need_bytes = tic->t_unit_res; - if ((ntic = log->l_write_headq)) { + if (!list_empty(&log->l_writeq)) { + struct xlog_ticket *ntic; free_bytes = xlog_space_left(log, log->l_grant_write_cycle, log->l_grant_write_bytes); - do { + list_for_each_entry(ntic, &log->l_writeq, t_queue) { ASSERT(ntic->t_flags & XLOG_TIC_PERM_RESERV); if (free_bytes < ntic->t_unit_res) break; free_bytes -= ntic->t_unit_res; sv_signal(&ntic->t_wait); - ntic = ntic->t_next; - } while (ntic != log->l_write_headq); + } - if (ntic != log->l_write_headq) { - if ((tic->t_flags & XLOG_TIC_IN_Q) == 0) - xlog_ins_ticketq(&log->l_write_headq, tic); + if (ntic != list_first_entry(&log->l_writeq, + struct xlog_ticket, t_queue)) { + if (list_empty(&tic->t_queue)) + list_add_tail(&tic->t_queue, &log->l_writeq); trace_xfs_log_regrant_write_sleep1(log, tic); @@ -2727,8 +2695,8 @@ redo: free_bytes = xlog_space_left(log, log->l_grant_write_cycle, log->l_grant_write_bytes); if (free_bytes < need_bytes) { - if ((tic->t_flags & XLOG_TIC_IN_Q) == 0) - xlog_ins_ticketq(&log->l_write_headq, tic); + if (list_empty(&tic->t_queue)) + list_add_tail(&tic->t_queue, &log->l_writeq); spin_unlock(&log->l_grant_lock); xlog_grant_push_ail(log->l_mp, need_bytes); spin_lock(&log->l_grant_lock); @@ -2745,8 +2713,9 @@ redo: trace_xfs_log_regrant_write_wake2(log, tic); goto redo; - } else if (tic->t_flags & XLOG_TIC_IN_Q) - xlog_del_ticketq(&log->l_write_headq, tic); + } + + list_del_init(&tic->t_queue); /* we've got enough space */ xlog_grant_add_space_write(log, need_bytes); @@ -2766,9 +2735,7 @@ redo: error_return: - if (tic->t_flags & XLOG_TIC_IN_Q) - xlog_del_ticketq(&log->l_reserve_headq, tic); - + list_del_init(&tic->t_queue); trace_xfs_log_regrant_write_error(log, tic); /* @@ -3435,6 +3402,7 @@ xlog_ticket_alloc( } atomic_set(&tic->t_ref, 1); + INIT_LIST_HEAD(&tic->t_queue); tic->t_unit_res = unit_bytes; tic->t_curr_res = unit_bytes; tic->t_cnt = cnt; @@ -3742,26 +3710,17 @@ xfs_log_force_umount( spin_unlock(&log->l_icloglock); /* - * We don't want anybody waiting for log reservations - * after this. That means we have to wake up everybody - * queued up on reserve_headq as well as write_headq. - * In addition, we make sure in xlog_{re}grant_log_space - * that we don't enqueue anything once the SHUTDOWN flag - * is set, and this action is protected by the GRANTLOCK. + * We don't want anybody waiting for log reservations after this. That + * means we have to wake up everybody queued up on reserveq as well as + * writeq. In addition, we make sure in xlog_{re}grant_log_space that + * we don't enqueue anything once the SHUTDOWN flag is set, and this + * action is protected by the GRANTLOCK. */ - if ((tic = log->l_reserve_headq)) { - do { - sv_signal(&tic->t_wait); - tic = tic->t_next; - } while (tic != log->l_reserve_headq); - } + list_for_each_entry(tic, &log->l_reserveq, t_queue) + sv_signal(&tic->t_wait); - if ((tic = log->l_write_headq)) { - do { - sv_signal(&tic->t_wait); - tic = tic->t_next; - } while (tic != log->l_write_headq); - } + list_for_each_entry(tic, &log->l_writeq, t_queue) + sv_signal(&tic->t_wait); spin_unlock(&log->l_grant_lock); if (!(log->l_iclog->ic_state & XLOG_STATE_IOERROR)) { -- cgit v1.1