From 4a038677df4da84e42fd68b5ab2dfa4d82baa444 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Thu, 13 Jan 2011 19:59:49 +0000 Subject: dm log userspace: trap all failed log construction errors When constructing a mirror log, it is possible for the initial request to fail for other reasons besides -ESRCH. These must be handled too. Signed-off-by: Jonathan Brassow Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-log-userspace-base.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/md/dm-log-userspace-base.c') diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c index 1ed0094f064b..1c25ad3d02a2 100644 --- a/drivers/md/dm-log-userspace-base.c +++ b/drivers/md/dm-log-userspace-base.c @@ -181,8 +181,11 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_CTR, ctr_str, str_size, NULL, NULL); - if (r == -ESRCH) { - DMERR("Userspace log server not found"); + if (r < 0) { + if (r == -ESRCH) + DMERR("Userspace log server not found"); + else + DMERR("Userspace log server failed to create log"); goto out; } @@ -214,10 +217,9 @@ out: static void userspace_dtr(struct dm_dirty_log *log) { - int r; struct log_c *lc = log->context; - r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_DTR, + (void) dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_DTR, NULL, 0, NULL, NULL); -- cgit v1.2.2 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/dm-log-userspace-base.c') 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 v1.2.2 From 085ae0651b2791f3a430ddb76da92925b9952e13 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Thu, 13 Jan 2011 19:59:51 +0000 Subject: dm log userspace: group clear and mark requests Allow the device-mapper log's 'mark' and 'clear' requests to be grouped and processed in a batch. This can significantly reduce the amount of traffic going between the kernel and userspace (where the processing daemon resides). Signed-off-by: Jonathan Brassow Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-log-userspace-base.c | 102 ++++++++++++++++++++++++++++--------- 1 file changed, 79 insertions(+), 23 deletions(-) (limited to 'drivers/md/dm-log-userspace-base.c') diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c index 767adf300fa5..31e1687e7bf6 100644 --- a/drivers/md/dm-log-userspace-base.c +++ b/drivers/md/dm-log-userspace-base.c @@ -18,6 +18,14 @@ struct flush_entry { struct list_head list; }; +/* + * This limit on the number of mark and clear request is, to a degree, + * arbitrary. However, there is some basis for the choice in the limits + * imposed on the size of data payload by dm-log-userspace-transfer.c: + * dm_consult_userspace(). + */ +#define MAX_FLUSH_GROUP_COUNT 32 + struct log_c { struct dm_target *ti; uint32_t region_size; @@ -348,6 +356,71 @@ static int userspace_in_sync(struct dm_dirty_log *log, region_t region, return (r) ? 0 : (int)in_sync; } +static int flush_one_by_one(struct log_c *lc, struct list_head *flush_list) +{ + int r = 0; + struct flush_entry *fe; + + list_for_each_entry(fe, flush_list, list) { + r = userspace_do_request(lc, lc->uuid, fe->type, + (char *)&fe->region, + sizeof(fe->region), + NULL, NULL); + if (r) + break; + } + + return r; +} + +static int flush_by_group(struct log_c *lc, struct list_head *flush_list) +{ + int r = 0; + int count; + uint32_t type = 0; + struct flush_entry *fe, *tmp_fe; + LIST_HEAD(tmp_list); + uint64_t group[MAX_FLUSH_GROUP_COUNT]; + + /* + * Group process the requests + */ + while (!list_empty(flush_list)) { + count = 0; + + list_for_each_entry_safe(fe, tmp_fe, flush_list, list) { + group[count] = fe->region; + count++; + + list_del(&fe->list); + list_add(&fe->list, &tmp_list); + + type = fe->type; + if (count >= MAX_FLUSH_GROUP_COUNT) + break; + } + + r = userspace_do_request(lc, lc->uuid, type, + (char *)(group), + count * sizeof(uint64_t), + NULL, NULL); + if (r) { + /* Group send failed. Attempt one-by-one. */ + list_splice_init(&tmp_list, flush_list); + r = flush_one_by_one(lc, flush_list); + break; + } + } + + /* + * Must collect flush_entrys that were successfully processed + * as a group so that they will be free'd by the caller. + */ + list_splice_init(&tmp_list, flush_list); + + return r; +} + /* * userspace_flush * @@ -382,30 +455,13 @@ static int userspace_flush(struct dm_dirty_log *log) if (list_empty(&mark_list) && list_empty(&clear_list)) return 0; - /* - * FIXME: Count up requests, group request types, - * allocate memory to stick all requests in and - * send to server in one go. Failing the allocation, - * do it one by one. - */ - - 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; - } + r = flush_by_group(lc, &mark_list); + 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), - NULL, NULL); - if (r) - goto fail; - } + r = flush_by_group(lc, &clear_list); + if (r) + goto fail; r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH, NULL, 0, NULL, NULL); -- cgit v1.2.2 From 86a54a4802df10d23ccd655e2083e812fe990243 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Thu, 13 Jan 2011 19:59:52 +0000 Subject: dm log userspace: add version number to comms This patch adds a 'version' field to the 'dm_ulog_request' structure. The 'version' field is taken from a portion of the unused 'padding' field in the 'dm_ulog_request' structure. This was done to avoid changing the size of the structure and possibly disrupting backwards compatibility. The version number will help notify user-space daemons when a change has been made to the kernel/userspace log API. Signed-off-by: Jonathan Brassow Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-log-userspace-base.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/md/dm-log-userspace-base.c') diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c index 31e1687e7bf6..aa2e0c374ab3 100644 --- a/drivers/md/dm-log-userspace-base.c +++ b/drivers/md/dm-log-userspace-base.c @@ -12,6 +12,8 @@ #include "dm-log-userspace-transfer.h" +#define DM_LOG_USERSPACE_VSN "1.1.0" + struct flush_entry { int type; region_t region; @@ -765,7 +767,7 @@ static int __init userspace_dirty_log_init(void) return r; } - DMINFO("version 1.0.0 loaded"); + DMINFO("version " DM_LOG_USERSPACE_VSN " loaded"); return 0; } @@ -775,7 +777,7 @@ static void __exit userspace_dirty_log_exit(void) dm_ulog_tfr_exit(); mempool_destroy(flush_entry_pool); - DMINFO("version 1.0.0 unloaded"); + DMINFO("version " DM_LOG_USERSPACE_VSN " unloaded"); return; } -- cgit v1.2.2