This patch is still pretty raw. Outside of general clean-up, the main
area that needs work is the communications piece (dm-clog-tfr.c). For
some log requests, we need only know that the request was received. It
would be nice if I could use the ACK field in cn_msg and not have to
wait for a full reply. There's lots of other work to be done in that
area too. (Is linux-net the appropriate list for asking questions about
connector?)
Comments welcome,
brassow
Index: linux-2.6.22-rc1-mm1/drivers/md/dm-clog-tfr.c
===================================================================
--- /dev/null
+++ linux-2.6.22-rc1-mm1/drivers/md/dm-clog-tfr.c
@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) 2006 Red Hat, Inc.
+ *
+ * This file is released under the LGPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <net/sock.h>
+#include <linux/workqueue.h>
+#include <linux/dm-clog-tfr.h>
+#include <linux/connector.h>
+#include "dm.h"
+#define DM_MSG_PREFIX "mirror cluster log"
+
+#define RQ_TYPE(x) \
+ ((x) == DM_CLOG_CTR) ? "DM_CLOG_CTR" : \
+ ((x) == DM_CLOG_DTR) ? "DM_CLOG_DTR" : \
+ ((x) == DM_CLOG_PRESUSPEND) ? "DM_CLOG_PRESUSPEND" : \
+ ((x) == DM_CLOG_POSTSUSPEND) ? "DM_CLOG_POSTSUSPEND" : \
+ ((x) == DM_CLOG_RESUME) ? "DM_CLOG_RESUME" : \
+ ((x) == DM_CLOG_GET_REGION_SIZE) ? "DM_CLOG_GET_REGION_SIZE" : \
+ ((x) == DM_CLOG_IS_CLEAN) ? "DM_CLOG_IS_CLEAN" : \
+ ((x) == DM_CLOG_IN_SYNC) ? "DM_CLOG_IN_SYNC" : \
+ ((x) == DM_CLOG_FLUSH) ? "DM_CLOG_FLUSH" : \
+ ((x) == DM_CLOG_MARK_REGION) ? "DM_CLOG_MARK_REGION" : \
+ ((x) == DM_CLOG_CLEAR_REGION) ? "DM_CLOG_CLEAR_REGION" : \
+ ((x) == DM_CLOG_GET_RESYNC_WORK) ? "DM_CLOG_GET_RESYNC_WORK" : \
+ ((x) == DM_CLOG_SET_REGION_SYNC) ? "DM_CLOG_SET_REGION_SYNC" : \
+ ((x) == DM_CLOG_GET_SYNC_COUNT) ? "DM_CLOG_GET_SYNC_COUNT" : \
+ ((x) == DM_CLOG_STATUS_INFO) ? "DM_CLOG_STATUS_INFO" : \
+ ((x) == DM_CLOG_STATUS_TABLE) ? "DM_CLOG_STATUS_TABLE" : \
+ NULL
+
+/*
+ * Pre-allocated space for speed
+ */
+#define DM_CLOG_PREALLOCED_SIZE 512
+static struct cn_msg *prealloced_cn_msg = NULL;
+static struct clog_tfr *prealloced_clog_tfr = NULL;
+
+static struct cb_id cn_clog_id = { 0x4, 0x1 };
+static DEFINE_MUTEX(_lock);
+static DECLARE_COMPLETION(recv_complete);
+
+struct in_pkg {
+ int data_size;
+ char data[1024];
+};
+
+struct in_pkg recieving;
+
+static int dm_clog_sendto_server(struct clog_tfr *tfr)
+{
+ int r;
+ int size;
+ struct cn_msg *msg = prealloced_cn_msg;
+
+ if (tfr != prealloced_clog_tfr) {
+ size = sizeof(*msg) + sizeof(struct clog_tfr) + tfr->data_size;
+ msg = kmalloc(size, GFP_NOIO);
+ if (!msg)
+ return -ENOMEM;
+ memcpy((msg + 1), tfr, sizeof(struct clog_tfr) + tfr->data_size);
+ }
+
+ memset(msg, 0, sizeof(*msg));
+
+ msg->id.idx = cn_clog_id.idx;
+ msg->id.val = cn_clog_id.val;
+ msg->ack = 0;
+ msg->seq = 0;
+ msg->len = sizeof(struct clog_tfr) + tfr->data_size;
+
+ r = cn_netlink_send(msg, 0, gfp_any());
+ if (msg != prealloced_cn_msg)
+ kfree(msg);
+
+ return r;
+}
+
+static void cn_clog_callback(void *data)
+{
+ struct cn_msg *msg = (struct cn_msg *)data;
+
+ memcpy(recieving.data, msg->data, msg->len);
+ recieving.data_size = msg->len;
+ complete(&recv_complete);
+}
+
+static int dm_clog_recvfrom_server(char *rdata, int *rdata_size)
+{
+ int r;
+ struct clog_tfr *tfr;
+
+ r = wait_for_completion_timeout(&recv_complete, 20*HZ);
+ if (!r)
+ return -ETIMEDOUT;
+
+ tfr = (struct clog_tfr *)recieving.data;
+ if (tfr->error) {
+ DMERR(" tfr->request_type = %s", RQ_TYPE(tfr->request_type));
+ DMERR(" tfr->data_size = %d", tfr->data_size);
+ DMERR(" tfr->error = %d", tfr->error);
+ } else if (rdata) {
+ if (*rdata_size < tfr->data_size)
+ return -ENOSPC;
+ memcpy(rdata, tfr->data, tfr->data_size);
+ *rdata_size = tfr->data_size;
+ }
+
+ return tfr->error;
+}
+
+/*
+ * dm_clog_consult_server
+ * @uuid: log's uuid (must be DM_UUID_LEN in size)
+ * @request_type:
+ * @data: data to tx to the server
+ * @data_size: size of data in bytes
+ * @rdata: place to put return data from server
+ * @rdata_size: value-result (amount of space given/amount of space used)
+ *
+ * Only one process at a time can communicate with the server.
+ * rdata_size is undefined on failure.
+ *
+ * Returns: 0 on success, -EXXX on failure
+ */
+int dm_clog_consult_server(const char *uuid, int request_type,
+ char *data, int data_size,
+ char *rdata, int *rdata_size)
+{
+ int r = 0;
+ int overhead_size = sizeof(struct clog_tfr *) + sizeof(struct cn_msg);
+ struct clog_tfr *tfr = prealloced_clog_tfr;
+
+ if (data_size > (DM_CLOG_PREALLOCED_SIZE - overhead_size)) {
+ DMINFO("Size of tfr exceeds preallocated size");
+ /* FIXME: is kmalloc sufficient if we need this much space? */
+ tfr = kmalloc(data_size + sizeof(*tfr), GFP_NOIO);
+ }
+
+ if (!tfr)
+ return -ENOMEM;
+
+ mutex_lock(&_lock);
+
+ memset(tfr, 0, data_size + sizeof(*tfr));
+ memcpy(tfr->uuid, uuid, DM_UUID_LEN);
+ tfr->request_type = request_type;
+ tfr->data_size = data_size;
+ if (data && data_size)
+ memcpy(tfr->data, data, data_size);
+
+ r = dm_clog_sendto_server(tfr);
+ if (r)
+ DMERR("Unable to send cluster log request to server: %d", r);
+ else
+ r = dm_clog_recvfrom_server(rdata, rdata_size);
+
+ if (tfr != (struct clog_tfr *)prealloced_clog_tfr)
+ kfree(tfr);
+
+ mutex_unlock(&_lock);
+
+ if (r)
+ DMERR("dm_clog_consult_server failed: %d", r);
+
+ return r;
+}
+
+int dm_clog_tfr_init(void)
+{
+ int r;
+ void *prealloced;
+
+ prealloced = kmalloc(DM_CLOG_PREALLOCED_SIZE, GFP_KERNEL);
+ if (!prealloced)
+ return -ENOMEM;
+
+ prealloced_cn_msg = prealloced;
+ prealloced_clog_tfr = prealloced + sizeof(struct cn_msg);
+
+ r = cn_add_callback(&cn_clog_id, "clulog", cn_clog_callback);
+ if (r) {
+ cn_del_callback(&cn_clog_id);
+ return r;
+ }
+
+ return 0;
+}
+
+void dm_clog_tfr_exit(void)
+{
+ cn_del_callback(&cn_clog_id);
+ kfree(prealloced_cn_msg);
+}
Index: linux-2.6.22-rc1-mm1/drivers/md/dm-clog.c
===================================================================
--- /dev/null
+++ linux-2.6.22-rc1-mm1/drivers/md/dm-clog.c
@@ -0,0 +1,658 @@
+/*
+ * Copyright (C) 2006 Red Hat, Inc.
+ *
+ * This file is released under the LGPL.
+ */
+
+#include "dm.h"
+#include "dm-log.h"
+#include <linux/dm-clog-tfr.h>
+
+#define DM_MSG_PREFIX "mirror cluster log"
+
+struct flush_entry {
+ int type;
+ region_t region;
+ struct list_head list;
+};
+
+struct log_c {
+ struct dm_target *ti;
+ uint32_t region_size;
+ region_t region_count;
+ char uuid[DM_UUID_LEN];
+
+ spinlock_t flush_lock;
+ struct list_head flush_list; /* only for clear and mark requests */
+};
+
+static mempool_t *flush_entry_pool = NULL;
+
+static void *flush_entry_alloc(gfp_t gfp_mask, void *pool_data)
+{
+ return kmalloc(sizeof(struct flush_entry), gfp_mask);
+}
+
+static void flush_entry_free(void *element, void *pool_data)
+{
+ kfree(element);
+}
+
+static int cluster_ctr(struct dirty_log *log, struct dm_target *ti,
+ unsigned int argc, char **argv, int disk_log)
+{
+ int i;
+ int r = 0;
+ int str_size;
+ char *ctr_str = NULL;
+ struct log_c *lc = NULL;
+ uint32_t region_size;
+ region_t region_count;
+
+ /* Already checked argument count */
+ if (disk_log != 0 && disk_log != 1)
+ return -EINVAL;
+
+ if (sscanf(argv[disk_log], "%u", ®ion_size) != 1) {
+ DMWARN("Invalid region size string");
+ return -EINVAL;
+ }
+
+ region_count = dm_sector_div_up(ti->len, region_size);
+
+ lc = kmalloc(sizeof(*lc), GFP_KERNEL);
+ if (!lc) {
+ DMWARN("Unable to allocate cluster log context.");
+ return -ENOMEM;
+ }
+
+ lc->ti = ti;
+ lc->region_size = region_size;
+ lc->region_count = region_count;
+
+ /* FIXME: Need to check size of uuid arg */
+ memcpy(lc->uuid, argv[1 + disk_log], DM_UUID_LEN);
+ spin_lock_init(&lc->flush_lock);
+ INIT_LIST_HEAD(&lc->flush_list);
+
+ for (i = 0, str_size = 0; i < argc; i++)
+ str_size = strlen(argv[i]) + 1; /* +1 for space between args */
+
+ str_size += 20; /* Max number of chars in a printed u64 number */
+
+ ctr_str = kmalloc(str_size, GFP_KERNEL);
+ if (!ctr_str) {
+ DMWARN("Unable to allocate memory for constructor string");
+ kfree(lc);
+ return -ENOMEM;
+ }
+
+ for (i = 0, str_size = 0; i < argc; i++)
+ str_size += sprintf(ctr_str + str_size, "%s ", argv[i]);
+ str_size += sprintf(ctr_str + str_size, "%llu", ti->len);
+
+ /* Send table string */
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_CTR,
+ ctr_str, str_size, NULL, NULL);
+
+ if (r == -ESRCH)
+ DMERR(" Userspace cluster log server not found");
+
+ log->context = lc;
+
+ if (r && lc)
+ kfree(lc);
+ if (ctr_str)
+ kfree(ctr_str);
+
+ return r;
+}
+
+/*
+ * cluster_core_ctr
+ * @log
+ * @ti
+ * @argc
+ * @argv
+ *
+ * argv contains:
+ * <region_size> <uuid> [[no]sync]
+ *
+ * Returns: 0 on success, -XXX on failure
+ */
+static int cluster_core_ctr(struct dirty_log *log, struct dm_target *ti,
+ unsigned int argc, char **argv)
+{
+ int i, r;
+ if ((argc < 2) || (argc > 3)) {
+ DMERR("Too %s arguments to clustered_core mirror log type.",
+ (argc < 2) ? "few" : "many");
+ DMERR(" %d arguments supplied:", argc);
+ for (i = 0; i < argc; i++)
+ DMERR(" %s", argv[i]);
+ return -EINVAL;
+ }
+
+ r = cluster_ctr(log, ti, argc, argv, 0);
+
+ return r;
+}
+
+
+/*
+ * cluster_core_ctr
+ * @log
+ * @ti
+ * @argc
+ * @argv
+ *
+ * argv contains:
+ * <disk> <region_size> <uuid> [[no]sync]
+ *
+ * Returns: 0 on success, -XXX on failure
+ */
+static int cluster_disk_ctr(struct dirty_log *log, struct dm_target *ti,
+ unsigned int argc, char **argv)
+{
+ int i;
+ if ((argc < 3) || (argc > 4)) {
+ DMERR("Too %s arguments to clustered_disk mirror log type.",
+ (argc < 3) ? "few" : "many");
+ DMERR(" %d arguments supplied:", argc);
+ for (i = 0; i < argc; i++)
+ DMERR(" %s", argv[i]);
+ return -EINVAL;
+ }
+
+ return cluster_ctr(log, ti, argc, argv, 1);
+}
+
+/*
+ * cluster_dtr
+ * @log
+ */
+static void cluster_dtr(struct dirty_log *log)
+{
+ int r;
+ struct log_c *lc = (struct log_c *)log->context;
+
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_DTR,
+ NULL, 0,
+ NULL, NULL);
+
+ /* FIXME: What do we do on failure? */
+
+ kfree(lc);
+
+ return;
+}
+
+/*
+ * cluster_presuspend
+ * @log
+ */
+static int cluster_presuspend(struct dirty_log *log)
+{
+ int r;
+ struct log_c *lc = (struct log_c *)log->context;
+
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_PRESUSPEND,
+ NULL, 0,
+ NULL, NULL);
+
+ return r;
+}
+
+/*
+ * cluster_postsuspend
+ * @log
+ */
+static int cluster_postsuspend(struct dirty_log *log)
+{
+ int r;
+ struct log_c *lc = (struct log_c *)log->context;
+
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_POSTSUSPEND,
+ NULL, 0,
+ NULL, NULL);
+
+ return r;
+}
+
+/*
+ * cluster_resume
+ * @log
+ */
+static int cluster_resume(struct dirty_log *log)
+{
+ int r;
+ struct log_c *lc = (struct log_c *)log->context;
+
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_RESUME,
+ NULL, 0,
+ NULL, NULL);
+
+ return r;
+}
+
+/*
+ * cluster_get_region_size
+ * @log
+ *
+ * Only called during mirror construction, ok to block.
+ *
+ * Returns: region size (doesn't fail)
+ */
+static uint32_t cluster_get_region_size(struct dirty_log *log)
+{
+ struct log_c *lc = (struct log_c *)log->context;
+
+ return lc->region_size;
+}
+
+/*
+ * cluster_is_clean
+ * @log
+ * @region
+ *
+ * Check whether a region is clean. If there is any sort of
+ * failure when consulting the server, we return not clean.
+ *
+ * Returns: 1 if clean, 0 otherwise
+ */
+static int cluster_is_clean(struct dirty_log *log, region_t region)
+{
+ int r;
+ int is_clean;
+ int rdata_size;
+ struct log_c *lc = (struct log_c *)log->context;
+
+ rdata_size = sizeof(is_clean);
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_IS_CLEAN,
+ (char *)®ion, sizeof(region),
+ (char *)&is_clean, &rdata_size);
+
+ return (r) ? 0 : is_clean;
+}
+
+/*
+ * cluster_in_sync
+ * @log
+ * @region
+ * @can_block: if set, return immediately
+ *
+ * Check if the region is in-sync. If there is any sort
+ * of failure when consulting the server, we assume that
+ * the region is not in sync.
+ *
+ * Returns: 1 if in-sync, 0 if not-in-sync, -EWOULDBLOCK
+ */
+static int cluster_in_sync(struct dirty_log *log, region_t region, int can_block)
+{
+ int r;
+ int in_sync;
+ int rdata_size;
+ struct log_c *lc = (struct log_c *)log->context;
+
+ if (!can_block)
+ return -EWOULDBLOCK;
+
+ rdata_size = sizeof(in_sync);
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_IN_SYNC,
+ (char *)®ion, sizeof(region),
+ (char *)&in_sync, &rdata_size);
+ return (r) ? 0 : in_sync;
+}
+
+/*
+ * cluster_flush
+ * @log
+ *
+ * This function is ok to block.
+ * The flush happens in two stages. First, it sends all
+ * clear/mark requests that are on the list. Then it
+ * tells the server to commit them. This gives the
+ * server a chance to optimise the commit to the cluster
+ * and/or disk, instead of doing it for every request.
+ *
+ * Additionally, we could implement another thread that
+ * sends the requests up to the server - reducing the
+ * load on flush. Then the flush would have less in
+ * the list and be responsible for the finishing commit.
+ *
+ * Returns: 0 on success, < 0 on failure
+ */
+static int cluster_flush(struct dirty_log *log)
+{
+ int r = 0;
+ int flags;
+ struct log_c *lc = (struct log_c *)log->context;
+ LIST_HEAD(flush_list);
+ struct flush_entry *fe, *tmp_fe;
+
+ spin_lock_irqsave(&lc->flush_lock, flags);
+ list_splice_init(&lc->flush_list, &flush_list);
+ spin_unlock_irqrestore(&lc->flush_lock, flags);
+
+ if (list_empty(&flush_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, &flush_list, list) {
+ r = dm_clog_consult_server(lc->uuid, fe->type,
+ (char *)&fe->region,
+ sizeof(fe->region),
+ NULL, NULL);
+ if (r)
+ goto fail;
+ }
+
+ do {
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_FLUSH,
+ NULL, 0, NULL, NULL);
+ if (r != -EAGAIN)
+ break;
+
+ DMINFO("Flush conflicts with recovery [delaying]");
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(HZ/4);
+ } while (1);
+
+fail:
+ /*
+ * We can safely remove these entries, even if failure.
+ * Calling code will recieve an error and will know that
+ * the log facility has failed.
+ */
+ list_for_each_entry_safe(fe, tmp_fe, &flush_list, list) {
+ list_del(&fe->list);
+ mempool_free(fe, flush_entry_pool);
+ }
+
+ return r;
+}
+
+/*
+ * cluster_mark_region
+ * @log
+ * @region
+ *
+ * This function should avoid blocking unless absolutely required.
+ * (Memory allocation is valid for blocking.)
+ */
+static void cluster_mark_region(struct dirty_log *log, region_t region)
+{
+ int flags;
+ struct log_c *lc = (struct log_c *)log->context;
+ struct flush_entry *fe;
+
+ /* Wait for an allocation, but _never_ fail */
+ fe = mempool_alloc(flush_entry_pool, GFP_NOIO);
+ BUG_ON(!fe);
+
+ spin_lock_irqsave(&lc->flush_lock, flags);
+ fe->type = DM_CLOG_MARK_REGION;
+ fe->region = region;
+ list_add(&fe->list, &lc->flush_list);
+ spin_unlock_irqrestore(&lc->flush_lock, flags);
+
+ return;
+}
+
+/*
+ * cluster_clear_region
+ * @log
+ * @region
+ *
+ * This function must not block.
+ * So, the alloc can't block. In the worst case, it is ok to
+ * fail. It would simply mean we can't clear the region.
+ * Does nothing to current sync context, but does mean
+ * the region will be re-sync'ed on a reload of the mirror
+ * even though it is in-sync.
+ */
+static void cluster_clear_region(struct dirty_log *log, region_t region)
+{
+ int flags;
+ struct log_c *lc = (struct log_c *)log->context;
+ struct flush_entry *fe;
+
+ /*
+ * If we fail to allocate, we skip the clearing of
+ * the region. This doesn't hurt us in any way, except
+ * to cause the region to be resync'ed when the
+ * device is activated next time.
+ */
+ fe = mempool_alloc(flush_entry_pool, GFP_ATOMIC);
+ if (!fe) {
+ DMERR("Failed to allocate memory to clear region.");
+ return;
+ }
+
+ spin_lock_irqsave(&lc->flush_lock, flags);
+ fe->type = DM_CLOG_CLEAR_REGION;
+ fe->region = region;
+ list_add(&fe->list, &lc->flush_list);
+ spin_unlock_irqrestore(&lc->flush_lock, flags);
+
+ return;
+}
+
+/*
+ * cluster_get_resync_work
+ * @log
+ * @region
+ *
+ * Get a region that needs recovery. It is valid to return
+ * an error for this function.
+ *
+ * Returns: 1 if region filled, 0 if no work, <0 on error
+ */
+static int cluster_get_resync_work(struct dirty_log *log, region_t *region)
+{
+ int r;
+ int rdata_size;
+ struct log_c *lc = (struct log_c *)log->context;
+ struct { int i; region_t r; } pkg;
+
+ rdata_size = sizeof(pkg);
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_GET_RESYNC_WORK,
+ NULL, 0,
+ (char *)&pkg, &rdata_size);
+
+ *region = pkg.r;
+ return (r) ? r : pkg.i;
+}
+
+/*
+ * cluster_set_region_sync
+ * @log
+ * @region
+ * @in_sync
+ *
+ * Set the sync status of a given region. This function
+ * must not fail.
+ */
+static void cluster_set_region_sync(struct dirty_log *log,
+ region_t region, int in_sync)
+{
+ int r;
+ struct log_c *lc = (struct log_c *)log->context;
+ struct { region_t r; int i; } pkg;
+
+ pkg.r = region;
+ pkg.i = in_sync;
+
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_SET_REGION_SYNC,
+ (char *)&pkg, sizeof(pkg),
+ NULL, NULL);
+
+ /* FIXME: It would be nice to be able to report failures */
+ return;
+}
+
+/*
+ * cluster_get_sync_count
+ * @log
+ *
+ * If there is any sort of failure when consulting the server,
+ * we assume that the sync count is zero.
+ *
+ * Returns: sync count on success, 0 on failure
+ */
+static region_t cluster_get_sync_count(struct dirty_log *log)
+{
+ int r;
+ int rdata_size;
+ region_t sync_count;
+ struct log_c *lc = (struct log_c *)log->context;
+
+ rdata_size = sizeof(sync_count);
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_GET_SYNC_COUNT,
+ NULL, 0,
+ (char *)&sync_count, &rdata_size);
+
+ return (r) ? 0 : sync_count;
+}
+
+/*
+ * cluster_status
+ * @log
+ * @status_type
+ * @result
+ * @maxlen
+ *
+ * Returns: amount of space consumed
+ */
+static int cluster_status(struct dirty_log *log, status_type_t status_type,
+ char *result, unsigned int maxlen)
+{
+ int r = 0;
+ unsigned int sz = maxlen;
+ struct log_c *lc = (struct log_c *)log->context;
+
+ switch(status_type) {
+ case STATUSTYPE_INFO:
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_STATUS_INFO,
+ NULL, 0,
+ result, &sz);
+ /*
+ * FIXME: If we fail to contact server, we should still
+ * populate this with parsible results
+ */
+ break;
+ case STATUSTYPE_TABLE:
+ /*
+ * FIXME: We probably have enough info to
+ * forgo contact with the server
+ */
+ r = dm_clog_consult_server(lc->uuid, DM_CLOG_STATUS_TABLE,
+ NULL, 0,
+ result, &sz);
+ break;
+ }
+ return (r) ? 0: sz;
+}
+
+static struct dirty_log_type _clustered_core_type = {
+ .name = "clustered_core",
+ .module = THIS_MODULE,
+ .ctr = cluster_core_ctr,
+ .dtr = cluster_dtr,
+ .presuspend = cluster_presuspend,
+ .postsuspend = cluster_postsuspend,
+ .resume = cluster_resume,
+ .get_region_size = cluster_get_region_size,
+ .is_clean = cluster_is_clean,
+ .in_sync = cluster_in_sync,
+ .flush = cluster_flush,
+ .mark_region = cluster_mark_region,
+ .clear_region = cluster_clear_region,
+ .get_resync_work = cluster_get_resync_work,
+ .set_region_sync = cluster_set_region_sync,
+ .get_sync_count = cluster_get_sync_count,
+ .status = cluster_status,
+};
+
+static struct dirty_log_type _clustered_disk_type = {
+ .name = "clustered_disk",
+ .module = THIS_MODULE,
+ .ctr = cluster_disk_ctr,
+ .dtr = cluster_dtr,
+ .presuspend = cluster_presuspend,
+ .postsuspend = cluster_postsuspend,
+ .resume = cluster_resume,
+ .get_region_size = cluster_get_region_size,
+ .is_clean = cluster_is_clean,
+ .in_sync = cluster_in_sync,
+ .flush = cluster_flush,
+ .mark_region = cluster_mark_region,
+ .clear_region = cluster_clear_region,
+ .get_resync_work = cluster_get_resync_work,
+ .set_region_sync = cluster_set_region_sync,
+ .get_sync_count = cluster_get_sync_count,
+ .status = cluster_status,
+};
+
+static int __init cluster_dirty_log_init(void)
+{
+ int r = 0;
+
+ flush_entry_pool = mempool_create(100, flush_entry_alloc,
+ flush_entry_free, NULL);
+
+ if (!flush_entry_pool) {
+ DMWARN("Unable to create flush_entry_pool: No memory.");
+ return -ENOMEM;
+ }
+
+ r = dm_clog_tfr_init();
+ if (r) {
+ DMWARN("Unable to initialize cluster log communications");
+ mempool_destroy(flush_entry_pool);
+ return r;
+ }
+
+ r = dm_register_dirty_log_type(&_clustered_core_type);
+ if (r) {
+ DMWARN("Couldn't register clustered_core dirty log type");
+ dm_clog_tfr_exit();
+ mempool_destroy(flush_entry_pool);
+ return r;
+ }
+
+ r = dm_register_dirty_log_type(&_clustered_disk_type);
+ if (r) {
+ DMWARN("Couldn't register clustered_disk dirty log type");
+ dm_unregister_dirty_log_type(&_clustered_core_type);
+ dm_clog_tfr_exit();
+ mempool_destroy(flush_entry_pool);
+ return r;
+ }
+
+ DMINFO("dm-clulog (built %s %s) installed", __DATE__, __TIME__);
+ return 0;
+}
+
+static void __exit cluster_dirty_log_exit(void)
+{
+ dm_unregister_dirty_log_type(&_clustered_disk_type);
+ dm_unregister_dirty_log_type(&_clustered_core_type);
+ dm_clog_tfr_exit();
+ mempool_destroy(flush_entry_pool);
+ DMINFO("dm-clulog (built %s %s) removed", __DATE__, __TIME__);
+ return;
+}
+
+module_init(cluster_dirty_log_init);
+module_exit(cluster_dirty_log_exit);
+
+MODULE_DESCRIPTION(DM_NAME " mirror cluster-aware log");
+MODULE_AUTHOR("Jonathan Brassow");
+MODULE_LICENSE("GPL");
Index: linux-2.6.22-rc1-mm1/drivers/md/Kconfig
===================================================================
--- linux-2.6.22-rc1-mm1.orig/drivers/md/Kconfig
+++ linux-2.6.22-rc1-mm1/drivers/md/Kconfig
@@ -241,6 +241,15 @@ config DM_MIRROR
Allow volume managers to mirror logical volumes, also
needed for live data migration tools such as 'pvmove'.
+config DM_CLOG
+ tristate "Mirror cluster logging (EXPERIMENTAL)"
+ depends on DM_MIRROR && EXPERIMENTAL
+ ---help---
+ Cluster logging allows mirroring to become cluster-aware.
+ Mirror devices can be used by multiple machines at the
+ same time. Note: this will not make your applications
+ cluster-aware.
+
config DM_ZERO
tristate "Zero target (EXPERIMENTAL)"
depends on BLK_DEV_DM && EXPERIMENTAL
Index: linux-2.6.22-rc1-mm1/drivers/md/Makefile
===================================================================
--- linux-2.6.22-rc1-mm1.orig/drivers/md/Makefile
+++ linux-2.6.22-rc1-mm1/drivers/md/Makefile
@@ -7,6 +7,7 @@ dm-mod-objs := dm.o dm-table.o dm-target
dm-multipath-objs := dm-hw-handler.o dm-path-selector.o dm-mpath.o
dm-snapshot-objs := dm-snap.o dm-exception-store.o
dm-mirror-objs := dm-log.o dm-raid1.o
+dm-clulog-objs := dm-clog.o dm-clog-tfr.o
md-mod-objs := md.o bitmap.o
raid456-objs := raid5.o raid6algos.o raid6recov.o raid6tables.o \
raid6int1.o raid6int2.o raid6int4.o \
@@ -36,6 +37,7 @@ obj-$(CONFIG_DM_MULTIPATH) += dm-multipa
obj-$(CONFIG_DM_MULTIPATH_EMC) += dm-emc.o
obj-$(CONFIG_DM_SNAPSHOT) += dm-snapshot.o
obj-$(CONFIG_DM_MIRROR) += dm-mirror.o
+obj-$(CONFIG_DM_CLOG) += dm-clulog.o
obj-$(CONFIG_DM_ZERO) += dm-zero.o
quiet_cmd_unroll = UNROLL $@
Index: linux-2.6.22-rc1-mm1/include/linux/dm-clog-tfr.h
===================================================================
--- /dev/null
+++ linux-2.6.22-rc1-mm1/include/linux/dm-clog-tfr.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2006 Red Hat, Inc.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef __DM_CLOG_TFR_H__
+#define __DM_CLOG_TFR_H__
+
+#include <linux/dm-ioctl.h> /* For DM_UUID_LEN */
+
+#ifndef NETLINK_DMCLOG
+#define NETLINK_DMCLOG 30
+#endif
+
+#define DM_CLOG_TFR_SIZE 1024
+
+#define DM_CLOG_CTR 1
+#define DM_CLOG_DTR 2
+#define DM_CLOG_PRESUSPEND 3
+#define DM_CLOG_POSTSUSPEND 4
+#define DM_CLOG_RESUME 5
+#define DM_CLOG_GET_REGION_SIZE 6
+#define DM_CLOG_IS_CLEAN 7
+#define DM_CLOG_IN_SYNC 8
+#define DM_CLOG_FLUSH 9
+#define DM_CLOG_MARK_REGION 10
+#define DM_CLOG_CLEAR_REGION 11
+#define DM_CLOG_GET_RESYNC_WORK 12
+#define DM_CLOG_SET_REGION_SYNC 13
+#define DM_CLOG_GET_SYNC_COUNT 14
+#define DM_CLOG_STATUS_INFO 15
+#define DM_CLOG_STATUS_TABLE 16
+
+struct clog_tfr {
+ uint64_t private[2];
+ char uuid[DM_UUID_LEN]; /* Ties a request to a specific mirror log */
+
+ int error; /* Used by server to inform of errors */
+ uint32_t originator; /* Cluster ID of this machine */
+
+ uint32_t request_type; /* DM_CLOG_* */
+ uint32_t data_size; /* How much data (not including this struct) */
+ char data[0];
+};
+
+#ifdef __KERNEL__
+int dm_clog_tfr_init(void);
+void dm_clog_tfr_exit(void);
+int dm_clog_consult_server(const char *uuid, int request_type,
+ char *data, int data_size,
+ char *rdata, int *rdata_size);
+#endif
+
+#endif /* __DM_CLOG_TFR_H__ */
--
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