diff options
Diffstat (limited to 'fs/xfs/xfs_log_cil.c')
| -rw-r--r-- | fs/xfs/xfs_log_cil.c | 1338 |
1 files changed, 1005 insertions, 333 deletions
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c index 48435cf2aa16..eccbfb99e894 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -37,17 +37,160 @@ xlog_cil_ticket_alloc( { struct xlog_ticket *tic; - tic = xlog_ticket_alloc(log, 0, 1, XFS_TRANSACTION, 0, - KM_NOFS); + tic = xlog_ticket_alloc(log, 0, 1, 0); /* * set the current reservation to zero so we know to steal the basic * transaction overhead reservation from the first transaction commit. */ tic->t_curr_res = 0; + tic->t_iclog_hdrs = 0; return tic; } +static inline void +xlog_cil_set_iclog_hdr_count(struct xfs_cil *cil) +{ + struct xlog *log = cil->xc_log; + + atomic_set(&cil->xc_iclog_hdrs, + (XLOG_CIL_BLOCKING_SPACE_LIMIT(log) / + (log->l_iclog_size - log->l_iclog_hsize))); +} + +/* + * Check if the current log item was first committed in this sequence. + * We can't rely on just the log item being in the CIL, we have to check + * the recorded commit sequence number. + * + * Note: for this to be used in a non-racy manner, it has to be called with + * CIL flushing locked out. As a result, it should only be used during the + * transaction commit process when deciding what to format into the item. + */ +static bool +xlog_item_in_current_chkpt( + struct xfs_cil *cil, + struct xfs_log_item *lip) +{ + if (test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)) + return false; + + /* + * li_seq is written on the first commit of a log item to record the + * first checkpoint it is written to. Hence if it is different to the + * current sequence, we're in a new checkpoint. + */ + return lip->li_seq == READ_ONCE(cil->xc_current_sequence); +} + +bool +xfs_log_item_in_current_chkpt( + struct xfs_log_item *lip) +{ + return xlog_item_in_current_chkpt(lip->li_log->l_cilp, lip); +} + +/* + * Unavoidable forward declaration - xlog_cil_push_work() calls + * xlog_cil_ctx_alloc() itself. + */ +static void xlog_cil_push_work(struct work_struct *work); + +static struct xfs_cil_ctx * +xlog_cil_ctx_alloc(void) +{ + struct xfs_cil_ctx *ctx; + + ctx = kmem_zalloc(sizeof(*ctx), KM_NOFS); + INIT_LIST_HEAD(&ctx->committing); + INIT_LIST_HEAD(&ctx->busy_extents); + INIT_LIST_HEAD(&ctx->log_items); + INIT_LIST_HEAD(&ctx->lv_chain); + INIT_WORK(&ctx->push_work, xlog_cil_push_work); + return ctx; +} + +/* + * Aggregate the CIL per cpu structures into global counts, lists, etc and + * clear the percpu state ready for the next context to use. This is called + * from the push code with the context lock held exclusively, hence nothing else + * will be accessing or modifying the per-cpu counters. + */ +static void +xlog_cil_push_pcp_aggregate( + struct xfs_cil *cil, + struct xfs_cil_ctx *ctx) +{ + struct xlog_cil_pcp *cilpcp; + int cpu; + + for_each_online_cpu(cpu) { + cilpcp = per_cpu_ptr(cil->xc_pcp, cpu); + + ctx->ticket->t_curr_res += cilpcp->space_reserved; + cilpcp->space_reserved = 0; + + if (!list_empty(&cilpcp->busy_extents)) { + list_splice_init(&cilpcp->busy_extents, + &ctx->busy_extents); + } + if (!list_empty(&cilpcp->log_items)) + list_splice_init(&cilpcp->log_items, &ctx->log_items); + + /* + * We're in the middle of switching cil contexts. Reset the + * counter we use to detect when the current context is nearing + * full. + */ + cilpcp->space_used = 0; + } +} + +/* + * Aggregate the CIL per-cpu space used counters into the global atomic value. + * This is called when the per-cpu counter aggregation will first pass the soft + * limit threshold so we can switch to atomic counter aggregation for accurate + * detection of hard limit traversal. + */ +static void +xlog_cil_insert_pcp_aggregate( + struct xfs_cil *cil, + struct xfs_cil_ctx *ctx) +{ + struct xlog_cil_pcp *cilpcp; + int cpu; + int count = 0; + + /* Trigger atomic updates then aggregate only for the first caller */ + if (!test_and_clear_bit(XLOG_CIL_PCP_SPACE, &cil->xc_flags)) + return; + + for_each_online_cpu(cpu) { + int old, prev; + + cilpcp = per_cpu_ptr(cil->xc_pcp, cpu); + do { + old = cilpcp->space_used; + prev = cmpxchg(&cilpcp->space_used, old, 0); + } while (old != prev); + count += old; + } + atomic_add(count, &ctx->space_used); +} + +static void +xlog_cil_ctx_switch( + struct xfs_cil *cil, + struct xfs_cil_ctx *ctx) +{ + xlog_cil_set_iclog_hdr_count(cil); + set_bit(XLOG_CIL_EMPTY, &cil->xc_flags); + set_bit(XLOG_CIL_PCP_SPACE, &cil->xc_flags); + ctx->sequence = ++cil->xc_current_sequence; + ctx->cil = cil; + cil->xc_ctx = ctx; +} + /* * After the first stage of log recovery is done, we know where the head and * tail of the log are. We need this log initialisation done before we can @@ -64,6 +207,7 @@ xlog_cil_init_post_recovery( { log->l_cilp->xc_ctx->ticket = xlog_cil_ticket_alloc(log); log->l_cilp->xc_ctx->sequence = 1; + xlog_cil_set_iclog_hdr_count(log->l_cilp); } static inline int @@ -154,13 +298,20 @@ xlog_cil_alloc_shadow_bufs( } /* - * We 64-bit align the length of each iovec so that the start - * of the next one is naturally aligned. We'll need to - * account for that slack space here. Then round nbytes up - * to 64-bit alignment so that the initial buffer alignment is - * easy to calculate and verify. + * We 64-bit align the length of each iovec so that the start of + * the next one is naturally aligned. We'll need to account for + * that slack space here. + * + * We also add the xlog_op_header to each region when + * formatting, but that's not accounted to the size of the item + * at this point. Hence we'll need an addition number of bytes + * for each vector to hold an opheader. + * + * Then round nbytes up to 64-bit alignment so that the initial + * buffer alignment is easy to calculate and verify. */ - nbytes += niovecs * sizeof(uint64_t); + nbytes += niovecs * + (sizeof(uint64_t) + sizeof(struct xlog_op_header)); nbytes = round_up(nbytes, sizeof(uint64_t)); /* @@ -176,19 +327,19 @@ xlog_cil_alloc_shadow_bufs( */ if (!lip->li_lv_shadow || buf_size > lip->li_lv_shadow->lv_size) { - /* * We free and allocate here as a realloc would copy - * unnecessary data. We don't use kmem_zalloc() for the + * unnecessary data. We don't use kvzalloc() for the * same reason - we don't need to zero the data area in * the buffer, only the log vector header and the iovec * storage. */ kmem_free(lip->li_lv_shadow); + lv = xlog_kvmalloc(buf_size); - lv = kmem_alloc_large(buf_size, KM_NOFS); memset(lv, 0, xlog_cil_iovec_space(niovecs)); + INIT_LIST_HEAD(&lv->lv_list); lv->lv_item = lip; lv->lv_size = buf_size; if (ordered) @@ -204,7 +355,6 @@ xlog_cil_alloc_shadow_bufs( else lv->lv_buf_len = 0; lv->lv_bytes = 0; - lv->lv_next = NULL; } /* Ensure the lv is set up according to ->iop_size */ @@ -218,29 +368,25 @@ xlog_cil_alloc_shadow_bufs( /* * Prepare the log item for insertion into the CIL. Calculate the difference in - * log space and vectors it will consume, and if it is a new item pin it as - * well. + * log space it will consume, and if it is a new item pin it as well. */ STATIC void xfs_cil_prepare_item( struct xlog *log, struct xfs_log_vec *lv, struct xfs_log_vec *old_lv, - int *diff_len, - int *diff_iovecs) + int *diff_len) { /* Account for the new LV being passed in */ - if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) { + if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) *diff_len += lv->lv_bytes; - *diff_iovecs += lv->lv_niovecs; - } /* * If there is no old LV, this is the first time we've seen the item in * this CIL context and so we need to pin it. If we are replacing the * old_lv, then remove the space it accounts for and make it the shadow * buffer for later freeing. In both cases we are now switching to the - * shadow buffer, so update the the pointer to it appropriately. + * shadow buffer, so update the pointer to it appropriately. */ if (!old_lv) { if (lv->lv_item->li_ops->iop_pin) @@ -250,7 +396,6 @@ xfs_cil_prepare_item( ASSERT(lv->lv_buf_len != XFS_LOG_VEC_ORDERED); *diff_len -= old_lv->lv_bytes; - *diff_iovecs -= old_lv->lv_niovecs; lv->lv_item->li_lv_shadow = old_lv; } @@ -299,12 +444,10 @@ static void xlog_cil_insert_format_items( struct xlog *log, struct xfs_trans *tp, - int *diff_len, - int *diff_iovecs) + int *diff_len) { struct xfs_log_item *lip; - /* Bail out if we didn't find a log item. */ if (list_empty(&tp->t_items)) { ASSERT(0); @@ -338,7 +481,6 @@ xlog_cil_insert_format_items( if (lip->li_lv && shadow->lv_size <= lip->li_lv->lv_size) { /* same or smaller, optimise common overwrite case */ lv = lip->li_lv; - lv->lv_next = NULL; if (ordered) goto insert; @@ -347,7 +489,6 @@ xlog_cil_insert_format_items( * set the item up as though it is a new insertion so * that the space reservation accounting is correct. */ - *diff_iovecs -= lv->lv_niovecs; *diff_len -= lv->lv_bytes; /* Ensure the lv is set up according to ->iop_size */ @@ -372,11 +513,28 @@ xlog_cil_insert_format_items( ASSERT(IS_ALIGNED((unsigned long)lv->lv_buf, sizeof(uint64_t))); lip->li_ops->iop_format(lip, lv); insert: - xfs_cil_prepare_item(log, lv, old_lv, diff_len, diff_iovecs); + xfs_cil_prepare_item(log, lv, old_lv, diff_len); } } /* + * The use of lockless waitqueue_active() requires that the caller has + * serialised itself against the wakeup call in xlog_cil_push_work(). That + * can be done by either holding the push lock or the context lock. + */ +static inline bool +xlog_cil_over_hard_limit( + struct xlog *log, + int32_t space_used) +{ + if (waitqueue_active(&log->l_cilp->xc_push_wait)) + return true; + if (space_used >= XLOG_CIL_BLOCKING_SPACE_LIMIT(log)) + return true; + return false; +} + +/* * Insert the log items into the CIL and calculate the difference in space * consumed by the item. Add the space to the checkpoint ticket and calculate * if the change requires additional log metadata. If it does, take that space @@ -386,15 +544,17 @@ insert: static void xlog_cil_insert_items( struct xlog *log, - struct xfs_trans *tp) + struct xfs_trans *tp, + uint32_t released_space) { struct xfs_cil *cil = log->l_cilp; struct xfs_cil_ctx *ctx = cil->xc_ctx; struct xfs_log_item *lip; int len = 0; - int diff_iovecs = 0; - int iclog_space; int iovhdr_res = 0, split_res = 0, ctx_res = 0; + int space_used; + int order; + struct xlog_cil_pcp *cilpcp; ASSERT(tp); @@ -402,51 +562,114 @@ xlog_cil_insert_items( * We can do this safely because the context can't checkpoint until we * are done so it doesn't matter exactly how we update the CIL. */ - xlog_cil_insert_format_items(log, tp, &len, &diff_iovecs); + xlog_cil_insert_format_items(log, tp, &len); + + /* + * Subtract the space released by intent cancelation from the space we + * consumed so that we remove it from the CIL space and add it back to + * the current transaction reservation context. + */ + len -= released_space; + + /* + * Grab the per-cpu pointer for the CIL before we start any accounting. + * That ensures that we are running with pre-emption disabled and so we + * can't be scheduled away between split sample/update operations that + * are done without outside locking to serialise them. + */ + cilpcp = get_cpu_ptr(cil->xc_pcp); + + /* + * We need to take the CIL checkpoint unit reservation on the first + * commit into the CIL. Test the XLOG_CIL_EMPTY bit first so we don't + * unnecessarily do an atomic op in the fast path here. We can clear the + * XLOG_CIL_EMPTY bit as we are under the xc_ctx_lock here and that + * needs to be held exclusively to reset the XLOG_CIL_EMPTY bit. + */ + if (test_bit(XLOG_CIL_EMPTY, &cil->xc_flags) && + test_and_clear_bit(XLOG_CIL_EMPTY, &cil->xc_flags)) + ctx_res = ctx->ticket->t_unit_res; - spin_lock(&cil->xc_cil_lock); + /* + * Check if we need to steal iclog headers. atomic_read() is not a + * locked atomic operation, so we can check the value before we do any + * real atomic ops in the fast path. If we've already taken the CIL unit + * reservation from this commit, we've already got one iclog header + * space reserved so we have to account for that otherwise we risk + * overrunning the reservation on this ticket. + * + * If the CIL is already at the hard limit, we might need more header + * space that originally reserved. So steal more header space from every + * commit that occurs once we are over the hard limit to ensure the CIL + * push won't run out of reservation space. + * + * This can steal more than we need, but that's OK. + * + * The cil->xc_ctx_lock provides the serialisation necessary for safely + * calling xlog_cil_over_hard_limit() in this context. + */ + space_used = atomic_read(&ctx->space_used) + cilpcp->space_used + len; + if (atomic_read(&cil->xc_iclog_hdrs) > 0 || + xlog_cil_over_hard_limit(log, space_used)) { + split_res = log->l_iclog_hsize + + sizeof(struct xlog_op_header); + if (ctx_res) + ctx_res += split_res * (tp->t_ticket->t_iclog_hdrs - 1); + else + ctx_res = split_res * tp->t_ticket->t_iclog_hdrs; + atomic_sub(tp->t_ticket->t_iclog_hdrs, &cil->xc_iclog_hdrs); + } + cilpcp->space_reserved += ctx_res; - /* account for space used by new iovec headers */ - iovhdr_res = diff_iovecs * sizeof(xlog_op_header_t); - len += iovhdr_res; - ctx->nvecs += diff_iovecs; + /* + * Accurately account when over the soft limit, otherwise fold the + * percpu count into the global count if over the per-cpu threshold. + */ + if (!test_bit(XLOG_CIL_PCP_SPACE, &cil->xc_flags)) { + atomic_add(len, &ctx->space_used); + } else if (cilpcp->space_used + len > + (XLOG_CIL_SPACE_LIMIT(log) / num_online_cpus())) { + space_used = atomic_add_return(cilpcp->space_used + len, + &ctx->space_used); + cilpcp->space_used = 0; + /* + * If we just transitioned over the soft limit, we need to + * transition to the global atomic counter. + */ + if (space_used >= XLOG_CIL_SPACE_LIMIT(log)) + xlog_cil_insert_pcp_aggregate(cil, ctx); + } else { + cilpcp->space_used += len; + } /* attach the transaction to the CIL if it has any busy extents */ if (!list_empty(&tp->t_busy)) - list_splice_init(&tp->t_busy, &ctx->busy_extents); + list_splice_init(&tp->t_busy, &cilpcp->busy_extents); /* - * Now transfer enough transaction reservation to the context ticket - * for the checkpoint. The context ticket is special - the unit - * reservation has to grow as well as the current reservation as we - * steal from tickets so we can correctly determine the space used - * during the transaction commit. + * Now update the order of everything modified in the transaction + * and insert items into the CIL if they aren't already there. + * We do this here so we only need to take the CIL lock once during + * the transaction commit. */ - if (ctx->ticket->t_curr_res == 0) { - ctx_res = ctx->ticket->t_unit_res; - ctx->ticket->t_curr_res = ctx_res; - tp->t_ticket->t_curr_res -= ctx_res; - } + order = atomic_inc_return(&ctx->order_id); + list_for_each_entry(lip, &tp->t_items, li_trans) { + /* Skip items which aren't dirty in this transaction. */ + if (!test_bit(XFS_LI_DIRTY, &lip->li_flags)) + continue; - /* do we need space for more log record headers? */ - iclog_space = log->l_iclog_size - log->l_iclog_hsize; - if (len > 0 && (ctx->space_used / iclog_space != - (ctx->space_used + len) / iclog_space)) { - split_res = (len + iclog_space - 1) / iclog_space; - /* need to take into account split region headers, too */ - split_res *= log->l_iclog_hsize + sizeof(struct xlog_op_header); - ctx->ticket->t_unit_res += split_res; - ctx->ticket->t_curr_res += split_res; - tp->t_ticket->t_curr_res -= split_res; - ASSERT(tp->t_ticket->t_curr_res >= len); + lip->li_order_id = order; + if (!list_empty(&lip->li_cil)) + continue; + list_add_tail(&lip->li_cil, &cilpcp->log_items); } - tp->t_ticket->t_curr_res -= len; - ctx->space_used += len; + put_cpu_ptr(cilpcp); /* * If we've overrun the reservation, dump the tx details before we move * the log items. Shutdown is imminent... */ + tp->t_ticket->t_curr_res -= ctx_res + len; if (WARN_ON(tp->t_ticket->t_curr_res < 0)) { xfs_warn(log->l_mp, "Transaction log reservation overrun:"); xfs_warn(log->l_mp, @@ -456,44 +679,20 @@ xlog_cil_insert_items( split_res); xfs_warn(log->l_mp, " ctx ticket: %d bytes", ctx_res); xlog_print_trans(tp); + xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); } - - /* - * Now (re-)position everything modified at the tail of the CIL. - * We do this here so we only need to take the CIL lock once during - * the transaction commit. - */ - list_for_each_entry(lip, &tp->t_items, li_trans) { - - /* Skip items which aren't dirty in this transaction. */ - if (!test_bit(XFS_LI_DIRTY, &lip->li_flags)) - continue; - - /* - * Only move the item if it isn't already at the tail. This is - * to prevent a transient list_empty() state when reinserting - * an item that is already the only item in the CIL. - */ - if (!list_is_last(&lip->li_cil, &cil->xc_cil)) - list_move_tail(&lip->li_cil, &cil->xc_cil); - } - - spin_unlock(&cil->xc_cil_lock); - - if (tp->t_ticket->t_curr_res < 0) - xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR); } static void xlog_cil_free_logvec( - struct xfs_log_vec *log_vector) + struct list_head *lv_chain) { struct xfs_log_vec *lv; - for (lv = log_vector; lv; ) { - struct xfs_log_vec *next = lv->lv_next; + while (!list_empty(lv_chain)) { + lv = list_first_entry(lv_chain, struct xfs_log_vec, lv_list); + list_del_init(&lv->lv_list); kmem_free(lv); - lv = next; } } @@ -536,7 +735,7 @@ xlog_discard_busy_extents( struct blk_plug plug; int error = 0; - ASSERT(mp->m_flags & XFS_MOUNT_DISCARD); + ASSERT(xfs_has_discard(mp)); blk_start_plug(&plug); list_for_each_entry(busyp, list, list) { @@ -546,7 +745,7 @@ xlog_discard_busy_extents( error = __blkdev_issue_discard(mp->m_ddev_targp->bt_bdev, XFS_AGB_TO_DADDR(mp, busyp->agno, busyp->bno), XFS_FSB_TO_BB(mp, busyp->length), - GFP_NOFS, 0, &bio); + GFP_NOFS, &bio); if (error && error != -EOPNOTSUPP) { xfs_info(mp, "discard failed for extent [0x%llx,%u], error %d", @@ -574,10 +773,10 @@ xlog_discard_busy_extents( */ static void xlog_cil_committed( - struct xfs_cil_ctx *ctx, - bool abort) + struct xfs_cil_ctx *ctx) { struct xfs_mount *mp = ctx->cil->xc_log->l_mp; + bool abort = xlog_is_shutdown(ctx->cil->xc_log); /* * If the I/O failed, we're aborting the commit and already shutdown. @@ -588,22 +787,23 @@ xlog_cil_committed( */ if (abort) { spin_lock(&ctx->cil->xc_push_lock); + wake_up_all(&ctx->cil->xc_start_wait); wake_up_all(&ctx->cil->xc_commit_wait); spin_unlock(&ctx->cil->xc_push_lock); } - xfs_trans_committed_bulk(ctx->cil->xc_log->l_ailp, ctx->lv_chain, + xfs_trans_committed_bulk(ctx->cil->xc_log->l_ailp, &ctx->lv_chain, ctx->start_lsn, abort); xfs_extent_busy_sort(&ctx->busy_extents); xfs_extent_busy_clear(mp, &ctx->busy_extents, - (mp->m_flags & XFS_MOUNT_DISCARD) && !abort); + xfs_has_discard(mp) && !abort); spin_lock(&ctx->cil->xc_push_lock); list_del(&ctx->committing); spin_unlock(&ctx->cil->xc_push_lock); - xlog_cil_free_logvec(ctx->lv_chain); + xlog_cil_free_logvec(&ctx->lv_chain); if (!list_empty(&ctx->busy_extents)) xlog_discard_busy_extents(mp, ctx); @@ -613,69 +813,414 @@ xlog_cil_committed( void xlog_cil_process_committed( - struct list_head *list, - bool aborted) + struct list_head *list) { struct xfs_cil_ctx *ctx; while ((ctx = list_first_entry_or_null(list, struct xfs_cil_ctx, iclog_entry))) { list_del(&ctx->iclog_entry); - xlog_cil_committed(ctx, aborted); + xlog_cil_committed(ctx); + } +} + +/* +* Record the LSN of the iclog we were just granted space to start writing into. +* If the context doesn't have a start_lsn recorded, then this iclog will +* contain the start record for the checkpoint. Otherwise this write contains +* the commit record for the checkpoint. +*/ +void +xlog_cil_set_ctx_write_state( + struct xfs_cil_ctx *ctx, + struct xlog_in_core *iclog) +{ + struct xfs_cil *cil = ctx->cil; + xfs_lsn_t lsn = be64_to_cpu(iclog->ic_header.h_lsn); + + ASSERT(!ctx->commit_lsn); + if (!ctx->start_lsn) { + spin_lock(&cil->xc_push_lock); + /* + * The LSN we need to pass to the log items on transaction + * commit is the LSN reported by the first log vector write, not + * the commit lsn. If we use the commit record lsn then we can + * move the grant write head beyond the tail LSN and overwrite + * it. + */ + ctx->start_lsn = lsn; + wake_up_all(&cil->xc_start_wait); + spin_unlock(&cil->xc_push_lock); + + /* + * Make sure the metadata we are about to overwrite in the log + * has been flushed to stable storage before this iclog is + * issued. + */ + spin_lock(&cil->xc_log->l_icloglock); + iclog->ic_flags |= XLOG_ICL_NEED_FLUSH; + spin_unlock(&cil->xc_log->l_icloglock); + return; + } + + /* + * Take a reference to the iclog for the context so that we still hold + * it when xlog_write is done and has released it. This means the + * context controls when the iclog is released for IO. + */ + atomic_inc(&iclog->ic_refcnt); + + /* + * xlog_state_get_iclog_space() guarantees there is enough space in the + * iclog for an entire commit record, so we can attach the context + * callbacks now. This needs to be done before we make the commit_lsn + * visible to waiters so that checkpoints with commit records in the + * same iclog order their IO completion callbacks in the same order that + * the commit records appear in the iclog. + */ + spin_lock(&cil->xc_log->l_icloglock); + list_add_tail(&ctx->iclog_entry, &iclog->ic_callbacks); + spin_unlock(&cil->xc_log->l_icloglock); + + /* + * Now we can record the commit LSN and wake anyone waiting for this + * sequence to have the ordered commit record assigned to a physical + * location in the log. + */ + spin_lock(&cil->xc_push_lock); + ctx->commit_iclog = iclog; + ctx->commit_lsn = lsn; + wake_up_all(&cil->xc_commit_wait); + spin_unlock(&cil->xc_push_lock); +} + + +/* + * Ensure that the order of log writes follows checkpoint sequence order. This + * relies on the context LSN being zero until the log write has guaranteed the + * LSN that the log write will start at via xlog_state_get_iclog_space(). + */ +enum _record_type { + _START_RECORD, + _COMMIT_RECORD, +}; + +static int +xlog_cil_order_write( + struct xfs_cil *cil, + xfs_csn_t sequence, + enum _record_type record) +{ + struct xfs_cil_ctx *ctx; + +restart: + spin_lock(&cil->xc_push_lock); + list_for_each_entry(ctx, &cil->xc_committing, committing) { + /* + * Avoid getting stuck in this loop because we were woken by the + * shutdown, but then went back to sleep once already in the + * shutdown state. + */ + if (xlog_is_shutdown(cil->xc_log)) { + spin_unlock(&cil->xc_push_lock); + return -EIO; + } + + /* + * Higher sequences will wait for this one so skip them. + * Don't wait for our own sequence, either. + */ + if (ctx->sequence >= sequence) + continue; + + /* Wait until the LSN for the record has been recorded. */ + switch (record) { + case _START_RECORD: + if (!ctx->start_lsn) { + xlog_wait(&cil->xc_start_wait, &cil->xc_push_lock); + goto restart; + } + break; + case _COMMIT_RECORD: + if (!ctx->commit_lsn) { + xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock); + goto restart; + } + break; + } + } + spin_unlock(&cil->xc_push_lock); + return 0; +} + +/* + * Write out the log vector change now attached to the CIL context. This will + * write a start record that needs to be strictly ordered in ascending CIL + * sequence order so that log recovery will always use in-order start LSNs when + * replaying checkpoints. + */ +static int +xlog_cil_write_chain( + struct xfs_cil_ctx *ctx, + uint32_t chain_len) +{ + struct xlog *log = ctx->cil->xc_log; + int error; + + error = xlog_cil_order_write(ctx->cil, ctx->sequence, _START_RECORD); + if (error) + return error; + return xlog_write(log, ctx, &ctx->lv_chain, ctx->ticket, chain_len); +} + +/* + * Write out the commit record of a checkpoint transaction to close off a + * running log write. These commit records are strictly ordered in ascending CIL + * sequence order so that log recovery will always replay the checkpoints in the + * correct order. + */ +static int +xlog_cil_write_commit_record( + struct xfs_cil_ctx *ctx) +{ + struct xlog *log = ctx->cil->xc_log; + struct xlog_op_header ophdr = { + .oh_clientid = XFS_TRANSACTION, + .oh_tid = cpu_to_be32(ctx->ticket->t_tid), + .oh_flags = XLOG_COMMIT_TRANS, + }; + struct xfs_log_iovec reg = { + .i_addr = &ophdr, + .i_len = sizeof(struct xlog_op_header), + .i_type = XLOG_REG_TYPE_COMMIT, + }; + struct xfs_log_vec vec = { + .lv_niovecs = 1, + .lv_iovecp = ®, + }; + int error; + LIST_HEAD(lv_chain); + list_add(&vec.lv_list, &lv_chain); + + if (xlog_is_shutdown(log)) + return -EIO; + + error = xlog_cil_order_write(ctx->cil, ctx->sequence, _COMMIT_RECORD); + if (error) + return error; + + /* account for space used by record data */ + ctx->ticket->t_curr_res -= reg.i_len; + error = xlog_write(log, ctx, &lv_chain, ctx->ticket, reg.i_len); + if (error) + xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); + return error; +} + +struct xlog_cil_trans_hdr { + struct xlog_op_header oph[2]; + struct xfs_trans_header thdr; + struct xfs_log_iovec lhdr[2]; +}; + +/* + * Build a checkpoint transaction header to begin the journal transaction. We + * need to account for the space used by the transaction header here as it is + * not accounted for in xlog_write(). + * + * This is the only place we write a transaction header, so we also build the + * log opheaders that indicate the start of a log transaction and wrap the + * transaction header. We keep the start record in it's own log vector rather + * than compacting them into a single region as this ends up making the logic + * in xlog_write() for handling empty opheaders for start, commit and unmount + * records much simpler. + */ +static void +xlog_cil_build_trans_hdr( + struct xfs_cil_ctx *ctx, + struct xlog_cil_trans_hdr *hdr, + struct xfs_log_vec *lvhdr, + int num_iovecs) +{ + struct xlog_ticket *tic = ctx->ticket; + __be32 tid = cpu_to_be32(tic->t_tid); + + memset(hdr, 0, sizeof(*hdr)); + + /* Log start record */ + hdr->oph[0].oh_tid = tid; + hdr->oph[0].oh_clientid = XFS_TRANSACTION; + hdr->oph[0].oh_flags = XLOG_START_TRANS; + + /* log iovec region pointer */ + hdr->lhdr[0].i_addr = &hdr->oph[0]; + hdr->lhdr[0].i_len = sizeof(struct xlog_op_header); + hdr->lhdr[0].i_type = XLOG_REG_TYPE_LRHEADER; + + /* log opheader */ + hdr->oph[1].oh_tid = tid; + hdr->oph[1].oh_clientid = XFS_TRANSACTION; + hdr->oph[1].oh_len = cpu_to_be32(sizeof(struct xfs_trans_header)); + + /* transaction header in host byte order format */ + hdr->thdr.th_magic = XFS_TRANS_HEADER_MAGIC; + hdr->thdr.th_type = XFS_TRANS_CHECKPOINT; + hdr->thdr.th_tid = tic->t_tid; + hdr->thdr.th_num_items = num_iovecs; + + /* log iovec region pointer */ + hdr->lhdr[1].i_addr = &hdr->oph[1]; + hdr->lhdr[1].i_len = sizeof(struct xlog_op_header) + + sizeof(struct xfs_trans_header); + hdr->lhdr[1].i_type = XLOG_REG_TYPE_TRANSHDR; + + lvhdr->lv_niovecs = 2; + lvhdr->lv_iovecp = &hdr->lhdr[0]; + lvhdr->lv_bytes = hdr->lhdr[0].i_len + hdr->lhdr[1].i_len; + + tic->t_curr_res -= lvhdr->lv_bytes; +} + +/* + * CIL item reordering compare function. We want to order in ascending ID order, + * but we want to leave items with the same ID in the order they were added to + * the list. This is important for operations like reflink where we log 4 order + * dependent intents in a single transaction when we overwrite an existing + * shared extent with a new shared extent. i.e. BUI(unmap), CUI(drop), + * CUI (inc), BUI(remap)... + */ +static int +xlog_cil_order_cmp( + void *priv, + const struct list_head *a, + const struct list_head *b) +{ + struct xfs_log_vec *l1 = container_of(a, struct xfs_log_vec, lv_list); + struct xfs_log_vec *l2 = container_of(b, struct xfs_log_vec, lv_list); + + return l1->lv_order_id > l2->lv_order_id; +} + +/* + * Pull all the log vectors off the items in the CIL, and remove the items from + * the CIL. We don't need the CIL lock here because it's only needed on the + * transaction commit side which is currently locked out by the flush lock. + * + * If a log item is marked with a whiteout, we do not need to write it to the + * journal and so we just move them to the whiteout list for the caller to + * dispose of appropriately. + */ +static void +xlog_cil_build_lv_chain( + struct xfs_cil_ctx *ctx, + struct list_head *whiteouts, + uint32_t *num_iovecs, + uint32_t *num_bytes) +{ + while (!list_empty(&ctx->log_items)) { + struct xfs_log_item *item; + struct xfs_log_vec *lv; + + item = list_first_entry(&ctx->log_items, + struct xfs_log_item, li_cil); + + if (test_bit(XFS_LI_WHITEOUT, &item->li_flags)) { + list_move(&item->li_cil, whiteouts); + trace_xfs_cil_whiteout_skip(item); + continue; + } + + lv = item->li_lv; + lv->lv_order_id = item->li_order_id; + + /* we don't write ordered log vectors */ + if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) + *num_bytes += lv->lv_bytes; + *num_iovecs += lv->lv_niovecs; + list_add_tail(&lv->lv_list, &ctx->lv_chain); + + list_del_init(&item->li_cil); + item->li_order_id = 0; + item->li_lv = NULL; + } +} + +static void +xlog_cil_cleanup_whiteouts( + struct list_head *whiteouts) +{ + while (!list_empty(whiteouts)) { + struct xfs_log_item *item = list_first_entry(whiteouts, + struct xfs_log_item, li_cil); + list_del_init(&item->li_cil); + trace_xfs_cil_whiteout_unpin(item); + item->li_ops->iop_unpin(item, 1); } } /* - * Push the Committed Item List to the log. If @push_seq flag is zero, then it - * is a background flush and so we can chose to ignore it. Otherwise, if the - * current sequence is the same as @push_seq we need to do a flush. If - * @push_seq is less than the current sequence, then it has already been + * Push the Committed Item List to the log. + * + * If the current sequence is the same as xc_push_seq we need to do a flush. If + * xc_push_seq is less than the current sequence, then it has already been * flushed and we don't need to do anything - the caller will wait for it to * complete if necessary. * - * @push_seq is a value rather than a flag because that allows us to do an - * unlocked check of the sequence number for a match. Hence we can allows log - * forces to run racily and not issue pushes for the same sequence twice. If we - * get a race between multiple pushes for the same sequence they will block on - * the first one and then abort, hence avoiding needless pushes. + * xc_push_seq is checked unlocked against the sequence number for a match. + * Hence we can allow log forces to run racily and not issue pushes for the + * same sequence twice. If we get a race between multiple pushes for the same + * sequence they will block on the first one and then abort, hence avoiding + * needless pushes. */ -STATIC int -xlog_cil_push( - struct xlog *log) +static void +xlog_cil_push_work( + struct work_struct *work) { - struct xfs_cil *cil = log->l_cilp; - struct xfs_log_vec *lv; - struct xfs_cil_ctx *ctx; + struct xfs_cil_ctx *ctx = + container_of(work, struct xfs_cil_ctx, push_work); + struct xfs_cil *cil = ctx->cil; + struct xlog *log = cil->xc_log; struct xfs_cil_ctx *new_ctx; - struct xlog_in_core *commit_iclog; - struct xlog_ticket *tic; - int num_iovecs; + int num_iovecs = 0; + int num_bytes = 0; int error = 0; - struct xfs_trans_header thdr; - struct xfs_log_iovec lhdr; - struct xfs_log_vec lvhdr = { NULL }; - xfs_lsn_t commit_lsn; - xfs_lsn_t push_seq; - - if (!cil) - return 0; - - new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_NOFS); + struct xlog_cil_trans_hdr thdr; + struct xfs_log_vec lvhdr = {}; + xfs_csn_t push_seq; + bool push_commit_stable; + LIST_HEAD (whiteouts); + struct xlog_ticket *ticket; + + new_ctx = xlog_cil_ctx_alloc(); new_ctx->ticket = xlog_cil_ticket_alloc(log); down_write(&cil->xc_ctx_lock); - ctx = cil->xc_ctx; spin_lock(&cil->xc_push_lock); push_seq = cil->xc_push_seq; ASSERT(push_seq <= ctx->sequence); + push_commit_stable = cil->xc_push_commit_stable; + cil->xc_push_commit_stable = false; + + /* + * As we are about to switch to a new, empty CIL context, we no longer + * need to throttle tasks on CIL space overruns. Wake any waiters that + * the hard push throttle may have caught so they can start committing + * to the new context. The ctx->xc_push_lock provides the serialisation + * necessary for safely using the lockless waitqueue_active() check in + * this context. + */ + if (waitqueue_active(&cil->xc_push_wait)) + wake_up_all(&cil->xc_push_wait); + + xlog_cil_push_pcp_aggregate(cil, ctx); /* * Check if we've anything to push. If there is nothing, then we don't * move on to a new sequence number and so we have to be able to push * this sequence again later. */ - if (list_empty(&cil->xc_cil)) { + if (test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)) { cil->xc_push_seq = 0; spin_unlock(&cil->xc_push_lock); goto out_skip; @@ -683,7 +1228,7 @@ xlog_cil_push( /* check for a previously pushed sequence */ - if (push_seq < cil->xc_ctx->sequence) { + if (push_seq < ctx->sequence) { spin_unlock(&cil->xc_push_lock); goto out_skip; } @@ -715,43 +1260,10 @@ xlog_cil_push( list_add(&ctx->committing, &cil->xc_committing); spin_unlock(&cil->xc_push_lock); - /* - * pull all the log vectors off the items in the CIL, and - * remove the items from the CIL. We don't need the CIL lock - * here because it's only needed on the transaction commit - * side which is currently locked out by the flush lock. - */ - lv = NULL; - num_iovecs = 0; - while (!list_empty(&cil->xc_cil)) { - struct xfs_log_item *item; - - item = list_first_entry(&cil->xc_cil, - struct xfs_log_item, li_cil); - list_del_init(&item->li_cil); - if (!ctx->lv_chain) - ctx->lv_chain = item->li_lv; - else - lv->lv_next = item->li_lv; - lv = item->li_lv; - item->li_lv = NULL; - num_iovecs += lv->lv_niovecs; - } + xlog_cil_build_lv_chain(ctx, &whiteouts, &num_iovecs, &num_bytes); /* - * initialise the new context and attach it to the CIL. Then attach - * the current context to the CIL committing lsit so it can be found - * during log forces to extract the commit lsn of the sequence that - * needs to be forced. - */ - INIT_LIST_HEAD(&new_ctx->committing); - INIT_LIST_HEAD(&new_ctx->busy_extents); - new_ctx->sequence = ctx->sequence + 1; - new_ctx->cil = cil; - cil->xc_ctx = new_ctx; - - /* - * The switch is now done, so we can drop the context lock and move out + * Switch the contexts so we can drop the context lock and move out * of a shared context. We can't just go straight to the commit record, * though - we need to synchronise with previous and future commits so * that the commit records are correctly ordered in the log to ensure @@ -769,126 +1281,136 @@ xlog_cil_push( * that higher sequences will wait for us to write out a commit record * before they do. * - * xfs_log_force_lsn requires us to mirror the new sequence into the cil + * xfs_log_force_seq requires us to mirror the new sequence into the cil * structure atomically with the addition of this sequence to the * committing list. This also ensures that we can do unlocked checks * against the current sequence in log forces without risking * deferencing a freed context pointer. */ spin_lock(&cil->xc_push_lock); - cil->xc_current_sequence = new_ctx->sequence; + xlog_cil_ctx_switch(cil, new_ctx); spin_unlock(&cil->xc_push_lock); up_write(&cil->xc_ctx_lock); /* + * Sort the log vector chain before we add the transaction headers. + * This ensures we always have the transaction headers at the start + * of the chain. + */ + list_sort(NULL, &ctx->lv_chain, xlog_cil_order_cmp); + + /* * Build a checkpoint transaction header and write it to the log to * begin the transaction. We need to account for the space used by the * transaction header here as it is not accounted for in xlog_write(). - * - * The LSN we need to pass to the log items on transaction commit is - * the LSN reported by the first log vector write. If we use the commit - * record lsn then we can move the tail beyond the grant write head. + * Add the lvhdr to the head of the lv chain we pass to xlog_write() so + * it gets written into the iclog first. */ - tic = ctx->ticket; - thdr.th_magic = XFS_TRANS_HEADER_MAGIC; - thdr.th_type = XFS_TRANS_CHECKPOINT; - thdr.th_tid = tic->t_tid; - thdr.th_num_items = num_iovecs; - lhdr.i_addr = &thdr; - lhdr.i_len = sizeof(xfs_trans_header_t); - lhdr.i_type = XLOG_REG_TYPE_TRANSHDR; - tic->t_curr_res -= lhdr.i_len + sizeof(xlog_op_header_t); - - lvhdr.lv_niovecs = 1; - lvhdr.lv_iovecp = &lhdr; - lvhdr.lv_next = ctx->lv_chain; - - error = xlog_write(log, &lvhdr, tic, &ctx->start_lsn, NULL, 0); + xlog_cil_build_trans_hdr(ctx, &thdr, &lvhdr, num_iovecs); + num_bytes += lvhdr.lv_bytes; + list_add(&lvhdr.lv_list, &ctx->lv_chain); + + /* + * Take the lvhdr back off the lv_chain immediately after calling + * xlog_cil_write_chain() as it should not be passed to log IO + * completion. + */ + error = xlog_cil_write_chain(ctx, num_bytes); + list_del(&lvhdr.lv_list); + if (error) + goto out_abort_free_ticket; + + error = xlog_cil_write_commit_record(ctx); if (error) goto out_abort_free_ticket; /* - * now that we've written the checkpoint into the log, strictly - * order the commit records so replay will get them in the right order. + * Grab the ticket from the ctx so we can ungrant it after releasing the + * commit_iclog. The ctx may be freed by the time we return from + * releasing the commit_iclog (i.e. checkpoint has been completed and + * callback run) so we can't reference the ctx after the call to + * xlog_state_release_iclog(). */ -restart: - spin_lock(&cil->xc_push_lock); - list_for_each_entry(new_ctx, &cil->xc_committing, committing) { - /* - * Avoid getting stuck in this loop because we were woken by the - * shutdown, but then went back to sleep once already in the - * shutdown state. - */ - if (XLOG_FORCED_SHUTDOWN(log)) { - spin_unlock(&cil->xc_push_lock); - goto out_abort_free_ticket; - } + ticket = ctx->ticket; - /* - * Higher sequences will wait for this one so skip them. - * Don't wait for our own sequence, either. - */ - if (new_ctx->sequence >= ctx->sequence) - continue; - if (!new_ctx->commit_lsn) { + /* + * If the checkpoint spans multiple iclogs, wait for all previous iclogs + * to complete before we submit the commit_iclog. We can't use state + * checks for this - ACTIVE can be either a past completed iclog or a + * future iclog being filled, while WANT_SYNC through SYNC_DONE can be a + * past or future iclog awaiting IO or ordered IO completion to be run. + * In the latter case, if it's a future iclog and we wait on it, the we + * will hang because it won't get processed through to ic_force_wait + * wakeup until this commit_iclog is written to disk. Hence we use the + * iclog header lsn and compare it to the commit lsn to determine if we + * need to wait on iclogs or not. + */ + spin_lock(&log->l_icloglock); + if (ctx->start_lsn != ctx->commit_lsn) { + xfs_lsn_t plsn; + + plsn = be64_to_cpu(ctx->commit_iclog->ic_prev->ic_header.h_lsn); + if (plsn && XFS_LSN_CMP(plsn, ctx->commit_lsn) < 0) { /* - * It is still being pushed! Wait for the push to - * complete, then start again from the beginning. + * Waiting on ic_force_wait orders the completion of + * iclogs older than ic_prev. Hence we only need to wait + * on the most recent older iclog here. */ - xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock); - goto restart; + xlog_wait_on_iclog(ctx->commit_iclog->ic_prev); + spin_lock(&log->l_icloglock); } - } - spin_unlock(&cil->xc_push_lock); - - /* xfs_log_done always frees the ticket on error. */ - commit_lsn = xfs_log_done(log->l_mp, tic, &commit_iclog, false); - if (commit_lsn == -1) - goto out_abort; - spin_lock(&commit_iclog->ic_callback_lock); - if (commit_iclog->ic_state == XLOG_STATE_IOERROR) { - spin_unlock(&commit_iclog->ic_callback_lock); - goto out_abort; + /* + * We need to issue a pre-flush so that the ordering for this + * checkpoint is correctly preserved down to stable storage. + */ + ctx->commit_iclog->ic_flags |= XLOG_ICL_NEED_FLUSH; } - ASSERT_ALWAYS(commit_iclog->ic_state == XLOG_STATE_ACTIVE || - commit_iclog->ic_state == XLOG_STATE_WANT_SYNC); - list_add_tail(&ctx->iclog_entry, &commit_iclog->ic_callbacks); - spin_unlock(&commit_iclog->ic_callback_lock); /* - * now the checkpoint commit is complete and we've attached the - * callbacks to the iclog we can assign the commit LSN to the context - * and wake up anyone who is waiting for the commit to complete. + * The commit iclog must be written to stable storage to guarantee + * journal IO vs metadata writeback IO is correctly ordered on stable + * storage. + * + * If the push caller needs the commit to be immediately stable and the + * commit_iclog is not yet marked as XLOG_STATE_WANT_SYNC to indicate it + * will be written when released, switch it's state to WANT_SYNC right + * now. */ - spin_lock(&cil->xc_push_lock); - ctx->commit_lsn = commit_lsn; - wake_up_all(&cil->xc_commit_wait); - spin_unlock(&cil->xc_push_lock); + ctx->commit_iclog->ic_flags |= XLOG_ICL_NEED_FUA; + if (push_commit_stable && + ctx->commit_iclog->ic_state == XLOG_STATE_ACTIVE) + xlog_state_switch_iclogs(log, ctx->commit_iclog, 0); + ticket = ctx->ticket; + xlog_state_release_iclog(log, ctx->commit_iclog, ticket); - /* release the hounds! */ - return xfs_log_release_iclog(log->l_mp, commit_iclog); + /* Not safe to reference ctx now! */ + + spin_unlock(&log->l_icloglock); + xlog_cil_cleanup_whiteouts(&whiteouts); + xfs_log_ticket_ungrant(log, ticket); + return; out_skip: up_write(&cil->xc_ctx_lock); xfs_log_ticket_put(new_ctx->ticket); kmem_free(new_ctx); - return 0; + return; out_abort_free_ticket: - xfs_log_ticket_put(tic); -out_abort: - xlog_cil_committed(ctx, true); - return -EIO; -} - -static void -xlog_cil_push_work( - struct work_struct *work) -{ - struct xfs_cil *cil = container_of(work, struct xfs_cil, - xc_push_work); - xlog_cil_push(cil->xc_log); + ASSERT(xlog_is_shutdown(log)); + xlog_cil_cleanup_whiteouts(&whiteouts); + if (!ctx->commit_iclog) { + xfs_log_ticket_ungrant(log, ctx->ticket); + xlog_cil_committed(ctx); + return; + } + spin_lock(&log->l_icloglock); + ticket = ctx->ticket; + xlog_state_release_iclog(log, ctx->commit_iclog, ticket); + /* Not safe to reference ctx now! */ + spin_unlock(&log->l_icloglock); + xfs_log_ticket_ungrant(log, ticket); } /* @@ -900,28 +1422,65 @@ xlog_cil_push_work( */ static void xlog_cil_push_background( - struct xlog *log) + struct xlog *log) __releases(cil->xc_ctx_lock) { struct xfs_cil *cil = log->l_cilp; + int space_used = atomic_read(&cil->xc_ctx->space_used); /* * The cil won't be empty because we are called while holding the - * context lock so whatever we added to the CIL will still be there + * context lock so whatever we added to the CIL will still be there. */ - ASSERT(!list_empty(&cil->xc_cil)); + ASSERT(!test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)); /* - * don't do a background push if we haven't used up all the - * space available yet. + * We are done if: + * - we haven't used up all the space available yet; or + * - we've already queued up a push; and + * - we're not over the hard limit; and + * - nothing has been over the hard limit. + * + * If so, we don't need to take the push lock as there's nothing to do. */ - if (cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log)) + if (space_used < XLOG_CIL_SPACE_LIMIT(log) || + (cil->xc_push_seq == cil->xc_current_sequence && + space_used < XLOG_CIL_BLOCKING_SPACE_LIMIT(log) && + !waitqueue_active(&cil->xc_push_wait))) { + up_read(&cil->xc_ctx_lock); return; + } spin_lock(&cil->xc_push_lock); if (cil->xc_push_seq < cil->xc_current_sequence) { cil->xc_push_seq = cil->xc_current_sequence; - queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work); + queue_work(cil->xc_push_wq, &cil->xc_ctx->push_work); } + + /* + * Drop the context lock now, we can't hold that if we need to sleep + * because we are over the blocking threshold. The push_lock is still + * held, so blocking threshold sleep/wakeup is still correctly + * serialised here. + */ + up_read(&cil->xc_ctx_lock); + + /* + * If we are well over the space limit, throttle the work that is being + * done until the push work on this context has begun. Enforce the hard + * throttle on all transaction commits once it has been activated, even + * if the committing transactions have resulted in the space usage + * dipping back down under the hard limit. + * + * The ctx->xc_push_lock provides the serialisation necessary for safely + * calling xlog_cil_over_hard_limit() in this context. + */ + if (xlog_cil_over_hard_limit(log, space_used)) { + trace_xfs_log_cil_wait(log, cil->xc_ctx->ticket); + ASSERT(space_used < log->l_logsize); + xlog_wait(&cil->xc_push_wait, &cil->xc_push_lock); + return; + } + spin_unlock(&cil->xc_push_lock); } @@ -929,13 +1488,26 @@ xlog_cil_push_background( /* * xlog_cil_push_now() is used to trigger an immediate CIL push to the sequence * number that is passed. When it returns, the work will be queued for - * @push_seq, but it won't be completed. The caller is expected to do any - * waiting for push_seq to complete if it is required. + * @push_seq, but it won't be completed. + * + * If the caller is performing a synchronous force, we will flush the workqueue + * to get previously queued work moving to minimise the wait time they will + * undergo waiting for all outstanding pushes to complete. The caller is + * expected to do the required waiting for push_seq to complete. + * + * If the caller is performing an async push, we need to ensure that the + * checkpoint is fully flushed out of the iclogs when we finish the push. If we + * don't do this, then the commit record may remain sitting in memory in an + * ACTIVE iclog. This then requires another full log force to push to disk, + * which defeats the purpose of having an async, non-blocking CIL force + * mechanism. Hence in this case we need to pass a flag to the push work to + * indicate it needs to flush the commit record itself. */ static void xlog_cil_push_now( struct xlog *log, - xfs_lsn_t push_seq) + xfs_lsn_t push_seq, + bool async) { struct xfs_cil *cil = log->l_cilp; @@ -945,20 +1517,32 @@ xlog_cil_push_now( ASSERT(push_seq && push_seq <= cil->xc_current_sequence); /* start on any pending background push to minimise wait time on it */ - flush_work(&cil->xc_push_work); + if (!async) + flush_workqueue(cil->xc_push_wq); + + spin_lock(&cil->xc_push_lock); + + /* + * If this is an async flush request, we always need to set the + * xc_push_commit_stable flag even if something else has already queued + * a push. The flush caller is asking for the CIL to be on stable + * storage when the next push completes, so regardless of who has queued + * the push, the flush requires stable semantics from it. + */ + cil->xc_push_commit_stable = async; /* * If the CIL is empty or we've already pushed the sequence then - * there's no work we need to do. + * there's no more work that we need to do. */ - spin_lock(&cil->xc_push_lock); - if (list_empty(&cil->xc_cil) || push_seq <= cil->xc_push_seq) { + if (test_bit(XLOG_CIL_EMPTY, &cil->xc_flags) || + push_seq <= cil->xc_push_seq) { spin_unlock(&cil->xc_push_lock); return; } cil->xc_push_seq = push_seq; - queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work); + queue_work(cil->xc_push_wq, &cil->xc_ctx->push_work); spin_unlock(&cil->xc_push_lock); } @@ -970,13 +1554,50 @@ xlog_cil_empty( bool empty = false; spin_lock(&cil->xc_push_lock); - if (list_empty(&cil->xc_cil)) + if (test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)) empty = true; spin_unlock(&cil->xc_push_lock); return empty; } /* + * If there are intent done items in this transaction and the related intent was + * committed in the current (same) CIL checkpoint, we don't need to write either + * the intent or intent done item to the journal as the change will be + * journalled atomically within this checkpoint. As we cannot remove items from + * the CIL here, mark the related intent with a whiteout so that the CIL push + * can remove it rather than writing it to the journal. Then remove the intent + * done item from the current transaction and release it so it doesn't get put + * into the CIL at all. + */ +static uint32_t +xlog_cil_process_intents( + struct xfs_cil *cil, + struct xfs_trans *tp) +{ + struct xfs_log_item *lip, *ilip, *next; + uint32_t len = 0; + + list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) { + if (!(lip->li_ops->flags & XFS_ITEM_INTENT_DONE)) + continue; + + ilip = lip->li_ops->iop_intent(lip); + if (!ilip || !xlog_item_in_current_chkpt(cil, ilip)) + continue; + set_bit(XFS_LI_WHITEOUT, &ilip->li_flags); + trace_xfs_cil_whiteout_mark(ilip); + len += ilip->li_lv->lv_bytes; + kmem_free(ilip->li_lv); + ilip->li_lv = NULL; + + xfs_trans_del_item(lip); + lip->li_ops->iop_release(lip); + } + return len; +} + +/* * Commit a transaction with the given vector to the Committed Item List. * * To do this, we need to format the item, pin it in memory if required and @@ -990,16 +1611,15 @@ xlog_cil_empty( * allowed again. */ void -xfs_log_commit_cil( - struct xfs_mount *mp, +xlog_cil_commit( + struct xlog *log, struct xfs_trans *tp, - xfs_lsn_t *commit_lsn, + xfs_csn_t *commit_seq, bool regrant) { - struct xlog *log = mp->m_log; struct xfs_cil *cil = log->l_cilp; struct xfs_log_item *lip, *next; - xfs_lsn_t xc_commit_lsn; + uint32_t released_space = 0; /* * Do all necessary memory allocation before we lock the CIL. @@ -1011,13 +1631,15 @@ xfs_log_commit_cil( /* lock out background commit */ down_read(&cil->xc_ctx_lock); - xlog_cil_insert_items(log, tp); + if (tp->t_flags & XFS_TRANS_HAS_INTENT_DONE) + released_space = xlog_cil_process_intents(cil, tp); - xc_commit_lsn = cil->xc_ctx->sequence; - if (commit_lsn) - *commit_lsn = xc_commit_lsn; + xlog_cil_insert_items(log, tp, released_space); - xfs_log_done(mp, tp->t_ticket, NULL, regrant); + if (regrant && !xlog_is_shutdown(log)) + xfs_log_ticket_regrant(log, tp->t_ticket); + else + xfs_log_ticket_ungrant(log, tp->t_ticket); tp->t_ticket = NULL; xfs_trans_unreserve_and_mod_sb(tp); @@ -1036,27 +1658,51 @@ xfs_log_commit_cil( list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) { xfs_trans_del_item(lip); if (lip->li_ops->iop_committing) - lip->li_ops->iop_committing(lip, xc_commit_lsn); + lip->li_ops->iop_committing(lip, cil->xc_ctx->sequence); } + if (commit_seq) + *commit_seq = cil->xc_ctx->sequence; + + /* xlog_cil_push_background() releases cil->xc_ctx_lock */ xlog_cil_push_background(log); +} - up_read(&cil->xc_ctx_lock); +/* + * Flush the CIL to stable storage but don't wait for it to complete. This + * requires the CIL push to ensure the commit record for the push hits the disk, + * but otherwise is no different to a push done from a log force. + */ +void +xlog_cil_flush( + struct xlog *log) +{ + xfs_csn_t seq = log->l_cilp->xc_current_sequence; + + trace_xfs_log_force(log->l_mp, seq, _RET_IP_); + xlog_cil_push_now(log, seq, true); + + /* + * If the CIL is empty, make sure that any previous checkpoint that may + * still be in an active iclog is pushed to stable storage. + */ + if (test_bit(XLOG_CIL_EMPTY, &log->l_cilp->xc_flags)) + xfs_log_force(log->l_mp, 0); } /* * Conditionally push the CIL based on the sequence passed in. * - * We only need to push if we haven't already pushed the sequence - * number given. Hence the only time we will trigger a push here is - * if the push sequence is the same as the current context. + * We only need to push if we haven't already pushed the sequence number given. + * Hence the only time we will trigger a push here is if the push sequence is + * the same as the current context. * * We return the current commit lsn to allow the callers to determine if a * iclog flush is necessary following this call. */ xfs_lsn_t -xlog_cil_force_lsn( +xlog_cil_force_seq( struct xlog *log, - xfs_lsn_t sequence) + xfs_csn_t sequence) { struct xfs_cil *cil = log->l_cilp; struct xfs_cil_ctx *ctx; @@ -1064,13 +1710,17 @@ xlog_cil_force_lsn( ASSERT(sequence <= cil->xc_current_sequence); + if (!sequence) + sequence = cil->xc_current_sequence; + trace_xfs_log_force(log->l_mp, sequence, _RET_IP_); + /* * check to see if we need to force out the current context. * xlog_cil_push() handles racing pushes for the same sequence, * so no need to deal with it here. */ restart: - xlog_cil_push_now(log, sequence); + xlog_cil_push_now(log, sequence, false); /* * See if we can find a previous sequence still committing. @@ -1085,7 +1735,7 @@ restart: * shutdown, but then went back to sleep once already in the * shutdown state. */ - if (XLOG_FORCED_SHUTDOWN(log)) + if (xlog_is_shutdown(log)) goto out_shutdown; if (ctx->sequence > sequence) continue; @@ -1094,6 +1744,7 @@ restart: * It is still being pushed! Wait for the push to * complete, then start again from the beginning. */ + XFS_STATS_INC(log->l_mp, xs_log_force_sleep); xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock); goto restart; } @@ -1119,7 +1770,7 @@ restart: * we would have found the context on the committing list. */ if (sequence == cil->xc_current_sequence && - !list_empty(&cil->xc_cil)) { + !test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)) { spin_unlock(&cil->xc_push_lock); goto restart; } @@ -1140,33 +1791,35 @@ out_shutdown: } /* - * Check if the current log item was first committed in this sequence. - * We can't rely on just the log item being in the CIL, we have to check - * the recorded commit sequence number. + * Move dead percpu state to the relevant CIL context structures. * - * Note: for this to be used in a non-racy manner, it has to be called with - * CIL flushing locked out. As a result, it should only be used during the - * transaction commit process when deciding what to format into the item. + * We have to lock the CIL context here to ensure that nothing is modifying + * the percpu state, either addition or removal. Both of these are done under + * the CIL context lock, so grabbing that exclusively here will ensure we can + * safely drain the cilpcp for the CPU that is dying. */ -bool -xfs_log_item_in_current_chkpt( - struct xfs_log_item *lip) +void +xlog_cil_pcp_dead( + struct xlog *log, + unsigned int cpu) { - struct xfs_cil_ctx *ctx; - - if (list_empty(&lip->li_cil)) - return false; - - ctx = lip->li_mountp->m_log->l_cilp->xc_ctx; + struct xfs_cil *cil = log->l_cilp; + struct xlog_cil_pcp *cilpcp = per_cpu_ptr(cil->xc_pcp, cpu); + struct xfs_cil_ctx *ctx; - /* - * li_seq is written on the first commit of a log item to record the - * first checkpoint it is written to. Hence if it is different to the - * current sequence, we're in a new checkpoint. - */ - if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0) - return false; - return true; + down_write(&cil->xc_ctx_lock); + ctx = cil->xc_ctx; + if (ctx->ticket) + ctx->ticket->t_curr_res += cilpcp->space_reserved; + cilpcp->space_reserved = 0; + + if (!list_empty(&cilpcp->log_items)) + list_splice_init(&cilpcp->log_items, &ctx->log_items); + if (!list_empty(&cilpcp->busy_extents)) + list_splice_init(&cilpcp->busy_extents, &ctx->busy_extents); + atomic_add(cilpcp->space_used, &ctx->space_used); + cilpcp->space_used = 0; + up_write(&cil->xc_ctx_lock); } /* @@ -1174,52 +1827,71 @@ xfs_log_item_in_current_chkpt( */ int xlog_cil_init( - struct xlog *log) + struct xlog *log) { - struct xfs_cil *cil; - struct xfs_cil_ctx *ctx; + struct xfs_cil *cil; + struct xfs_cil_ctx *ctx; + struct xlog_cil_pcp *cilpcp; + int cpu; cil = kmem_zalloc(sizeof(*cil), KM_MAYFAIL); if (!cil) return -ENOMEM; + /* + * Limit the CIL pipeline depth to 4 concurrent works to bound the + * concurrency the log spinlocks will be exposed to. + */ + cil->xc_push_wq = alloc_workqueue("xfs-cil/%s", + XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM | WQ_UNBOUND), + 4, log->l_mp->m_super->s_id); + if (!cil->xc_push_wq) + goto out_destroy_cil; - ctx = kmem_zalloc(sizeof(*ctx), KM_MAYFAIL); - if (!ctx) { - kmem_free(cil); - return -ENOMEM; + cil->xc_log = log; + cil->xc_pcp = alloc_percpu(struct xlog_cil_pcp); + if (!cil->xc_pcp) + goto out_destroy_wq; + + for_each_possible_cpu(cpu) { + cilpcp = per_cpu_ptr(cil->xc_pcp, cpu); + INIT_LIST_HEAD(&cilpcp->busy_extents); + INIT_LIST_HEAD(&cilpcp->log_items); } - INIT_WORK(&cil->xc_push_work, xlog_cil_push_work); - INIT_LIST_HEAD(&cil->xc_cil); INIT_LIST_HEAD(&cil->xc_committing); - spin_lock_init(&cil->xc_cil_lock); spin_lock_init(&cil->xc_push_lock); + init_waitqueue_head(&cil->xc_push_wait); init_rwsem(&cil->xc_ctx_lock); + init_waitqueue_head(&cil->xc_start_wait); init_waitqueue_head(&cil->xc_commit_wait); - - INIT_LIST_HEAD(&ctx->committing); - INIT_LIST_HEAD(&ctx->busy_extents); - ctx->sequence = 1; - ctx->cil = cil; - cil->xc_ctx = ctx; - cil->xc_current_sequence = ctx->sequence; - - cil->xc_log = log; log->l_cilp = cil; + + ctx = xlog_cil_ctx_alloc(); + xlog_cil_ctx_switch(cil, ctx); return 0; + +out_destroy_wq: + destroy_workqueue(cil->xc_push_wq); +out_destroy_cil: + kmem_free(cil); + return -ENOMEM; } void xlog_cil_destroy( struct xlog *log) { - if (log->l_cilp->xc_ctx) { - if (log->l_cilp->xc_ctx->ticket) - xfs_log_ticket_put(log->l_cilp->xc_ctx->ticket); - kmem_free(log->l_cilp->xc_ctx); + struct xfs_cil *cil = log->l_cilp; + + if (cil->xc_ctx) { + if (cil->xc_ctx->ticket) + xfs_log_ticket_put(cil->xc_ctx->ticket); + kmem_free(cil->xc_ctx); } - ASSERT(list_empty(&log->l_cilp->xc_cil)); - kmem_free(log->l_cilp); + ASSERT(test_bit(XLOG_CIL_EMPTY, &cil->xc_flags)); + free_percpu(cil->xc_pcp); + destroy_workqueue(cil->xc_push_wq); + kmem_free(cil); } |