From 909cc4fb48dd9870f6ebe4bd32cfbe37c102df62 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Thu, 13 Jan 2011 19:59:50 +0000 Subject: dm log userspace: split flush queue Split the 'flush_list', which contained a mix of both 'mark' and 'clear' requests, into two distinct lists ('mark_list' and 'clear_list'). The device mapper log implementations (used by various DM targets) are allowed to cache 'mark' and 'clear' requests until a 'flush' is received. Until now, these cached requests were kept in the same list. They will now be put into distinct lists to facilitate group processing of these requests (in the next patch). Signed-off-by: Jonathan Brassow Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-log-userspace-base.c | 41 +++++++++++++++++++++++++++++--------- 1 file changed, 32 insertions(+), 9 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c index 1c25ad3d02a2..767adf300fa5 100644 --- a/drivers/md/dm-log-userspace-base.c +++ b/drivers/md/dm-log-userspace-base.c @@ -37,8 +37,15 @@ struct log_c { */ uint64_t in_sync_hint; + /* + * Mark and clear requests are held until a flush is issued + * so that we can group, and thereby limit, the amount of + * network traffic between kernel and userspace. The 'flush_lock' + * is used to protect these lists. + */ spinlock_t flush_lock; - struct list_head flush_list; /* only for clear and mark requests */ + struct list_head mark_list; + struct list_head clear_list; }; static mempool_t *flush_entry_pool; @@ -169,7 +176,8 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, strncpy(lc->uuid, argv[0], DM_UUID_LEN); spin_lock_init(&lc->flush_lock); - INIT_LIST_HEAD(&lc->flush_list); + INIT_LIST_HEAD(&lc->mark_list); + INIT_LIST_HEAD(&lc->clear_list); str_size = build_constructor_string(ti, argc - 1, argv + 1, &ctr_str); if (str_size < 0) { @@ -362,14 +370,16 @@ static int userspace_flush(struct dm_dirty_log *log) int r = 0; unsigned long flags; struct log_c *lc = log->context; - LIST_HEAD(flush_list); + LIST_HEAD(mark_list); + LIST_HEAD(clear_list); struct flush_entry *fe, *tmp_fe; spin_lock_irqsave(&lc->flush_lock, flags); - list_splice_init(&lc->flush_list, &flush_list); + list_splice_init(&lc->mark_list, &mark_list); + list_splice_init(&lc->clear_list, &clear_list); spin_unlock_irqrestore(&lc->flush_lock, flags); - if (list_empty(&flush_list)) + if (list_empty(&mark_list) && list_empty(&clear_list)) return 0; /* @@ -379,7 +389,16 @@ static int userspace_flush(struct dm_dirty_log *log) * do it one by one. */ - list_for_each_entry(fe, &flush_list, list) { + list_for_each_entry(fe, &mark_list, list) { + r = userspace_do_request(lc, lc->uuid, fe->type, + (char *)&fe->region, + sizeof(fe->region), + NULL, NULL); + if (r) + goto fail; + } + + list_for_each_entry(fe, &clear_list, list) { r = userspace_do_request(lc, lc->uuid, fe->type, (char *)&fe->region, sizeof(fe->region), @@ -397,7 +416,11 @@ fail: * Calling code will receive an error and will know that * the log facility has failed. */ - list_for_each_entry_safe(fe, tmp_fe, &flush_list, list) { + list_for_each_entry_safe(fe, tmp_fe, &mark_list, list) { + list_del(&fe->list); + mempool_free(fe, flush_entry_pool); + } + list_for_each_entry_safe(fe, tmp_fe, &clear_list, list) { list_del(&fe->list); mempool_free(fe, flush_entry_pool); } @@ -427,7 +450,7 @@ static void userspace_mark_region(struct dm_dirty_log *log, region_t region) spin_lock_irqsave(&lc->flush_lock, flags); fe->type = DM_ULOG_MARK_REGION; fe->region = region; - list_add(&fe->list, &lc->flush_list); + list_add(&fe->list, &lc->mark_list); spin_unlock_irqrestore(&lc->flush_lock, flags); return; @@ -464,7 +487,7 @@ static void userspace_clear_region(struct dm_dirty_log *log, region_t region) spin_lock_irqsave(&lc->flush_lock, flags); fe->type = DM_ULOG_CLEAR_REGION; fe->region = region; - list_add(&fe->list, &lc->flush_list); + list_add(&fe->list, &lc->clear_list); spin_unlock_irqrestore(&lc->flush_lock, flags); return; -- cgit v1.2.3