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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 11 of 11] blktap2: add remus driver
# HG changeset patch
# User Brendan Cully <brendan@xxxxxxxxx>
# Date 1252530408 25200
# Node ID aaf56934865afa3f5611cd891347953cdd1e5729
# Parent 5e0779189ef3b9382675b2e574b75936a6e9fb15
blktap2: add remus driver
Blktap2 port of remus disk driver. Backwards compatable with blktap1
implementation.
Signed-off-by: Ryan O'Connor <rjo@xxxxxxxxx>
Signed-off-by: Brendan Cully <brendan@xxxxxxxxx>
diff --git a/tools/blktap2/drivers/Makefile b/tools/blktap2/drivers/Makefile
--- a/tools/blktap2/drivers/Makefile
+++ b/tools/blktap2/drivers/Makefile
@@ -36,7 +36,7 @@
CRYPT_LIB += -lcrypto
endif
-LDFLAGS_img := $(CRYPT_LIB) -lpthread -lz
+LDFLAGS_img := $(CRYPT_LIB) -lpthread -lz -lm
LIBS += -L$(LIBVHDDIR) -lvhd
@@ -44,6 +44,14 @@
LIBS += -luuid
endif
+REMUS-OBJS := block-remus.o
+REMUS-OBJS += hashtable.o
+REMUS-OBJS += hashtable_itr.o
+REMUS-OBJS += hashtable_utility.o
+
+$(REMUS-OBJS): CFLAGS += -fgnu89-inline -I$(XEN_XENSTORE)
+
+
LIBAIO_DIR = $(XEN_ROOT)/tools/libaio/src
tapdisk2 tapdisk-stream tapdisk-diff $(QCOW_UTIL): AIOLIBS :=
$(LIBAIO_DIR)/libaio.a
tapdisk-client tapdisk-stream tapdisk-diff $(QCOW_UTIL): CFLAGS +=
-I$(LIBAIO_DIR) -I$(XEN_LIBXC)
@@ -81,6 +89,7 @@
BLK-OBJS-y += block-qcow.o
BLK-OBJS-y += aes.o
BLK-OBJS-y += $(PORTABLE-OBJS-y)
+BLK-OBJS-y += $(REMUS-OBJS)
all: $(IBIN) lock-util qcow-util
diff --git a/tools/blktap2/drivers/block-remus.c
b/tools/blktap2/drivers/block-remus.c
new file mode 100644
--- /dev/null
+++ b/tools/blktap2/drivers/block-remus.c
@@ -0,0 +1,1670 @@
+/* block-remus.c
+ *
+ * This disk sends all writes to a backup via a network interface before
+ * passing them to an underlying device.
+ * The backup is a bit more complicated:
+ * 1. It applies all incoming writes to a ramdisk.
+ * 2. When a checkpoint request arrives, it moves the ramdisk to
+ * a committing state and uses a new ramdisk for subsequent writes.
+ * It also acknowledges the request, to let the sender know it can
+ * release output.
+ * 3. The ramdisk flushes its contents to the underlying driver.
+ * 4. At failover, the backup waits for the in-flight ramdisk (if any) to
+ * drain before letting the domain be activated.
+ *
+ * The driver determines whether it is the client or server by attempting
+ * to bind to the replication address. If the address is not local,
+ * the driver acts as client.
+ *
+ * The following messages are defined for the replication stream:
+ * 1. write request
+ * "wreq" 4
+ * num_sectors 4
+ * sector 8
+ * buffer (num_sectors * sector_size)
+ * 2. submit request (may be used as a barrier
+ * "sreq" 4
+ * 3. commit request
+ * "creq" 4
+ * After a commit request, the client must wait for a competion message:
+ * 4. completion
+ * "done" 4
+ */
+
+/* due to architectural choices in tapdisk, block-buffer is forced to
+ * reimplement some code which is meant to be private */
+#define TAPDISK
+#include "tapdisk.h"
+#include "tapdisk-server.h"
+#include "tapdisk-driver.h"
+#include "tapdisk-interface.h"
+#include "hashtable.h"
+#include "hashtable_itr.h"
+#include "hashtable_utility.h"
+
+#include <errno.h>
+#include <inttypes.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <sys/param.h>
+#include <sys/sysctl.h>
+#include <unistd.h>
+
+/* timeout for reads and writes in ms */
+#define NET_TIMEOUT 500
+#define RAMDISK_HASHSIZE 128
+
+/* connect retry timeout (seconds) */
+#define REMUS_CONNRETRY_TIMEOUT 10
+
+#define RPRINTF(_f, _a...) syslog (LOG_DEBUG, "remus: " _f, ## _a)
+
+enum tdremus_mode {
+ mode_invalid = 0,
+ mode_unprotected,
+ mode_primary,
+ mode_backup
+};
+
+struct tdremus_req {
+ uint64_t sector;
+ int nb_sectors;
+ char buf[4096];
+};
+
+struct req_ring {
+ /* waste one slot to distinguish between empty and full */
+ struct tdremus_req requests[MAX_REQUESTS * 2 + 1];
+ unsigned int head;
+ unsigned int tail;
+};
+
+/* TODO: This isn't very pretty, but to properly generate our own treqs (needed
+ * by the backup) we need to know our td_vbt_t and td_image_t (blktap2
+ * internals). As a proper fix, we should consider extending the tapdisk
+ * interface with a td_create_request() function, or something similar.
+ *
+ * For now, we just grab the vbd in the td_open() command, and the td_image_t
+ * from the first read request.
+ */
+td_vbd_t *device_vbd = NULL;
+td_image_t *remus_image = NULL;
+
+struct ramdisk {
+ size_t sector_size;
+ struct hashtable* h;
+ /* when a ramdisk is flushed, h is given a new empty hash for writes
+ * while the old ramdisk (prev) is drained asynchronously. To avoid
+ * a race where a read request points to a sector in prev which has
+ * not yet been flushed, check prev on a miss in h */
+ struct hashtable* prev;
+ /* count of outstanding requests to the base driver */
+ size_t inflight;
+};
+
+/* the ramdisk intercepts the original callback for reads and writes.
+ * This holds the original data. */
+/* Might be worth making this a static array in struct ramdisk to avoid
+ * a malloc per request */
+
+struct tdremus_state;
+
+struct ramdisk_cbdata {
+ td_callback_t cb;
+ void* private;
+ char* buf;
+ struct tdremus_state* state;
+};
+
+struct ramdisk_write_cbdata {
+ struct tdremus_state* state;
+ char* buf;
+};
+
+typedef void (*queue_rw_t) (td_driver_t *driver, td_request_t treq);
+
+/* poll_fd type for blktap2 fd system. taken from block_log.c */
+typedef struct poll_fd {
+ int fd;
+ event_id_t id;
+} poll_fd_t;
+
+struct tdremus_state {
+// struct tap_disk* driver;
+ void* driver_data;
+
+ /* XXX: this is needed so that the server can perform operations on
+ * the driver from the stream_fd event handler. fix this. */
+ td_driver_t *tdremus_driver;
+
+ /* TODO: we may wish to replace these two FIFOs with a unix socket */
+ char* ctl_path; /* receive flush instruction here */
+ poll_fd_t ctl_fd; /* io_fd slot for control FIFO */
+ char* msg_path; /* output completion message here */
+ poll_fd_t msg_fd;
+
+ /* replication host */
+ struct sockaddr_in sa;
+ poll_fd_t server_fd; /* server listen port */
+ poll_fd_t stream_fd; /* replication channel */
+
+ /* queue write requests, batch-replicate at submit */
+ struct req_ring write_ring;
+
+ /* ramdisk data*/
+ struct ramdisk ramdisk;
+
+ /* mode methods */
+ enum tdremus_mode mode;
+ int (*queue_flush)(td_driver_t *driver);
+};
+
+typedef struct tdremus_wire {
+ uint32_t op;
+ uint64_t id;
+ uint64_t sec;
+ uint32_t secs;
+} tdremus_wire_t;
+
+#define TDREMUS_READ "rreq"
+#define TDREMUS_WRITE "wreq"
+#define TDREMUS_SUBMIT "sreq"
+#define TDREMUS_COMMIT "creq"
+#define TDREMUS_DONE "done"
+#define TDREMUS_FAIL "fail"
+
+/* primary read/write functions */
+static void primary_queue_read(td_driver_t *driver, td_request_t treq);
+static void primary_queue_write(td_driver_t *driver, td_request_t treq);
+
+/* backup read/write functions */
+static void backup_queue_read(td_driver_t *driver, td_request_t treq);
+static void backup_queue_write(td_driver_t *driver, td_request_t treq);
+
+/* unpritected read/write functions */
+static void unprotected_queue_read(td_driver_t *driver, td_request_t treq);
+static void unprotected_queue_write(td_driver_t *driver, td_request_t treq);
+
+static int tdremus_close(td_driver_t *driver);
+
+static int switch_mode(td_driver_t *driver, enum tdremus_mode mode);
+static int ctl_respond(struct tdremus_state *s, const char *response);
+
+/* ring functions */
+static inline unsigned int ring_next(struct req_ring* ring, unsigned int pos)
+{
+ if (++pos >= MAX_REQUESTS * 2 + 1)
+ return 0;
+
+ return pos;
+}
+
+static inline int ring_isempty(struct req_ring* ring)
+{
+ return ring->head == ring->tail;
+}
+
+static inline int ring_isfull(struct req_ring* ring)
+{
+ return ring_next(ring, ring->tail) == ring->head;
+}
+
+/* functions to create and sumbit treq's */
+
+static void
+replicated_write_callback(td_request_t treq, int err)
+{
+ struct tdremus_state *s = (struct tdremus_state *) treq.cb_data;
+ td_vbd_request_t *vreq;
+
+ vreq = (td_vbd_request_t *) treq.private;
+
+ /* the write failed for now, lets panic. this is very bad */
+ if (err) {
+ RPRINTF("ramdisk write failed, disk image is not consistent\n");
+ exit(-1);
+ }
+
+ /* The write succeeded. let's pull the vreq off whatever request list
+ * it is on and free() it */
+ list_del(&vreq->next);
+ free(vreq);
+
+ s->ramdisk.inflight--;
+ if (!s->ramdisk.inflight && !s->ramdisk.prev) {
+ /* TODO: the ramdisk has been flushed */
+ }
+}
+
+static inline int
+create_write_request(struct tdremus_state *state, td_sector_t sec, int secs,
char *buf)
+{
+ td_request_t treq;
+ td_vbd_request_t *vreq;
+
+ treq.op = TD_OP_WRITE;
+ treq.buf = buf;
+ treq.sec = sec;
+ treq.secs = secs;
+ treq.image = remus_image;
+ treq.cb = replicated_write_callback;
+ treq.cb_data = state;
+ treq.id = 0;
+ treq.sidx = 0;
+
+ vreq = calloc(1, sizeof(td_vbd_request_t));
+ treq.private = vreq;
+
+ if(!vreq)
+ return -1;
+
+ vreq->submitting = 1;
+ INIT_LIST_HEAD(&vreq->next);
+ tapdisk_vbd_move_request(treq.private, &device_vbd->pending_requests);
+
+ /* TODO:
+ * we should probably leave it up to the caller to forward the request */
+ td_forward_request(treq);
+
+ vreq->submitting--;
+
+ return 0;
+}
+
+
+/* ramdisk methods */
+static int ramdisk_flush(td_driver_t *driver, struct tdremus_state *s);
+
+/* http://www.concentric.net/~Ttwang/tech/inthash.htm */
+static unsigned int uint64_hash(void* k)
+{
+ uint64_t key = *(uint64_t*)k;
+
+ key = (~key) + (key << 18);
+ key = key ^ (key >> 31);
+ key = key * 21;
+ key = key ^ (key >> 11);
+ key = key + (key << 6);
+ key = key ^ (key >> 22);
+
+ return (unsigned int)key;
+}
+
+static int rd_hash_equal(void* k1, void* k2)
+{
+ uint64_t key1, key2;
+
+ key1 = *(uint64_t*)k1;
+ key2 = *(uint64_t*)k2;
+
+ return key1 == key2;
+}
+
+static int ramdisk_read(struct ramdisk* ramdisk, uint64_t sector,
+ int nb_sectors, char* buf)
+{
+ int i;
+ char* v;
+ uint64_t key;
+
+ for (i = 0; i < nb_sectors; i++) {
+ key = sector + i;
+ if (!(v = hashtable_search(ramdisk->h, &key))) {
+ /* check whether it is queued in a previous flush request */
+ if (!(ramdisk->prev && (v = hashtable_search(ramdisk->prev, &key))))
+ return -1;
+ }
+ memcpy(buf + i * ramdisk->sector_size, v, ramdisk->sector_size);
+ }
+
+ return 0;
+}
+
+static int ramdisk_write_hash(struct hashtable* h, uint64_t sector, char* buf,
+ size_t len)
+{
+ char* v;
+ uint64_t* key;
+
+ if ((v = hashtable_search(h, §or))) {
+ memcpy(v, buf, len);
+ return 0;
+ }
+
+ if (!(v = malloc(len))) {
+ DPRINTF("ramdisk_write_hash: malloc failed\n");
+ return -1;
+ }
+ memcpy(v, buf, len);
+ if (!(key = malloc(sizeof(*key)))) {
+ DPRINTF("ramdisk_write_hash: error allocating key\n");
+ free(v);
+ return -1;
+ }
+ *key = sector;
+ if (!hashtable_insert(h, key, v)) {
+ DPRINTF("ramdisk_write_hash failed on sector %" PRIu64 "\n", sector);
+ free(key);
+ free(v);
+ return -1;
+ }
+
+ return 0;
+}
+
+static inline int ramdisk_write(struct ramdisk* ramdisk, uint64_t sector,
+ int nb_sectors, char* buf)
+{
+ int i, rc;
+
+ for (i = 0; i < nb_sectors; i++) {
+ rc = ramdisk_write_hash(ramdisk->h, sector + i,
+ buf + i * ramdisk->sector_size,
+ ramdisk->sector_size);
+ if (rc)
+ return rc;
+ }
+
+ return 0;
+}
+
+static int ramdisk_write_cb(td_driver_t *driver, int res, uint64_t sector,
+ int nb_sectors, int id, void* private)
+{
+ struct ramdisk_write_cbdata *cbdata = (struct ramdisk_write_cbdata*)private;
+ struct tdremus_state *s = cbdata->state;
+ int rc;
+
+ /*
+ RPRINTF("ramdisk write callback: rc %d, %d sectors @ %" PRIu64 "\n", res,
nb_sectors,
+ sector);
+ */
+
+ free(cbdata->buf);
+ free(cbdata);
+
+ s->ramdisk.inflight--;
+ if (!s->ramdisk.inflight && !s->ramdisk.prev) {
+ /* when this reaches 0 and prev is empty, the disk is flushed. */
+ /*
+ RPRINTF("ramdisk flush complete\n");
+ */
+ }
+
+ if (s->ramdisk.prev) {
+ /* resubmit as much as possible in the remaining disk */
+ /*
+ RPRINTF("calling ramdisk_flush from write callback\n");
+ */
+ return ramdisk_flush(driver, s);
+ }
+
+ return 0;
+}
+
+static int uint64_compare(const void* k1, const void* k2)
+{
+ uint64_t u1 = *(uint64_t*)k1;
+ uint64_t u2 = *(uint64_t*)k2;
+
+ /* u1 - u2 is unsigned */
+ return u1 < u2 ? -1 : u1 > u2 ? 1 : 0;
+}
+
+/* set psectors to an array of the sector numbers in the hash, returning
+ * the number of entries (or -1 on error) */
+static int ramdisk_get_sectors(struct hashtable* h, uint64_t** psectors)
+{
+ struct hashtable_itr* itr;
+ uint64_t* sectors;
+ int count;
+
+ if (!(count = hashtable_count(h)))
+ return 0;
+
+ if (!(*psectors = malloc(count * sizeof(uint64_t)))) {
+ DPRINTF("ramdisk_get_sectors: error allocating sector map\n");
+ return -1;
+ }
+ sectors = *psectors;
+
+ itr = hashtable_iterator(h);
+ count = 0;
+ do {
+ sectors[count++] = *(uint64_t*)hashtable_iterator_key(itr);
+ } while (hashtable_iterator_advance(itr));
+ free(itr);
+
+ return count;
+}
+
+static char* merge_requests(struct ramdisk* ramdisk, uint64_t start,
+ size_t count)
+{
+ char* buf;
+ char* sector;
+ int i;
+
+ if (!(buf = valloc(count * ramdisk->sector_size))) {
+ DPRINTF("merge_request: allocation failed\n");
+ return NULL;
+ }
+
+ for (i = 0; i < count; i++) {
+ if (!(sector = hashtable_search(ramdisk->prev, &start))) {
+ DPRINTF("merge_request: lookup failed on %"PRIu64"\n", start);
+ return NULL;
+ }
+
+ memcpy(buf + i * ramdisk->sector_size, sector, ramdisk->sector_size);
+ free(sector);
+
+ start++;
+ }
+
+ return buf;
+}
+
+/* The underlying driver may not handle having the whole ramdisk queued at
+ * once. We queue what we can and let the callbacks attempt to queue more. */
+/* NOTE: may be called from callback, while dd->private still belongs to
+ * the underlying driver */
+static int ramdisk_flush(td_driver_t *driver, struct tdremus_state* s)
+{
+ uint64_t* sectors;
+ char* buf;
+ uint64_t base, batchlen;
+ int i, j, count = 0;
+
+ // RPRINTF("ramdisk flush\n");
+
+ if ((count = ramdisk_get_sectors(s->ramdisk.prev, §ors)) <= 0)
+ return count;
+
+ /*
+ RPRINTF("ramdisk: flushing %d sectors\n", count);
+ */
+
+ /* sort and merge sectors to improve disk performance */
+ qsort(sectors, count, sizeof(*sectors), uint64_compare);
+
+ for (i = 0; i < count;) {
+ base = sectors[i++];
+ while (i < count && sectors[i] == sectors[i-1] + 1)
+ i++;
+ batchlen = sectors[i-1] - base + 1;
+
+ if (!(buf = merge_requests(&s->ramdisk, base, batchlen))) {
+ RPRINTF("ramdisk_flush: merge_requests failed\n");
+ free(sectors);
+ return -1;
+ }
+
+ /* NOTE: create_write_request() creates a treq AND forwards it down
+ * the driver chain */
+ // RPRINTF("forwarding write request at %" PRIu64 ", length: %" PRIu64
"\n", base, batchlen);
+ create_write_request(s, base, batchlen, buf);
+ //RPRINTF("write request at %" PRIu64 ", length: %" PRIu64 " forwarded\n",
base, batchlen);
+
+ s->ramdisk.inflight++;
+
+ for (j = 0; j < batchlen; j++) {
+ hashtable_remove(s->ramdisk.prev, &base);
+ base++;
+ }
+ }
+
+ if (!hashtable_count(s->ramdisk.prev)) {
+ /* everything is in flight */
+ hashtable_destroy(s->ramdisk.prev, 0);
+ s->ramdisk.prev = NULL;
+ }
+
+ free(sectors);
+
+ // RPRINTF("ramdisk flush done\n");
+ return 0;
+}
+
+/* flush ramdisk contents to disk */
+static int ramdisk_start_flush(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+ uint64_t* key;
+ char* buf;
+ int rc = 0;
+ int i, j, count, batchlen;
+ uint64_t* sectors;
+
+ if (!hashtable_count(s->ramdisk.h)) {
+ /*
+ RPRINTF("Nothing to flush\n");
+ */
+ return 0;
+ }
+
+ if (s->ramdisk.prev) {
+ /* a flush request issued while a previous flush is still in progress
+ * will merge with the previous request. If you want the previous
+ * request to be consistent, wait for it to complete. */
+ if ((count = ramdisk_get_sectors(s->ramdisk.h, §ors)) < 0)
+ return count;
+
+ for (i = 0; i < count; i++) {
+ buf = hashtable_search(s->ramdisk.h, sectors + i);
+ ramdisk_write_hash(s->ramdisk.prev, sectors[i], buf,
+ s->ramdisk.sector_size);
+ }
+ free(sectors);
+
+ hashtable_destroy (s->ramdisk.h, 0);
+ } else
+ s->ramdisk.prev = s->ramdisk.h;
+
+ /* We create a new hashtable so that new writes can be performed before
+ * the old hashtable is completely drained. */
+ s->ramdisk.h = create_hashtable(RAMDISK_HASHSIZE, uint64_hash,
+ rd_hash_equal);
+
+ return ramdisk_flush(driver, s);
+}
+
+
+static int ramdisk_start(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ if (s->ramdisk.h) {
+ RPRINTF("ramdisk already allocated\n");
+ return 0;
+ }
+
+ s->ramdisk.sector_size = driver->info.sector_size;
+ s->ramdisk.h = create_hashtable(RAMDISK_HASHSIZE, uint64_hash,
+ rd_hash_equal);
+
+ DPRINTF("Ramdisk started, %zu bytes/sector\n", s->ramdisk.sector_size);
+
+ return 0;
+}
+
+/* common client/server functions */
+/* mayberead: Time out after a certain interval. */
+static int mread(int fd, void* buf, size_t len)
+{
+ fd_set rfds;
+ int rc;
+ size_t cur = 0;
+ struct timeval tv = {
+ .tv_sec = 0,
+ .tv_usec = NET_TIMEOUT * 1000
+ };
+
+ if (!len)
+ return 0;
+
+ /* read first. Only select if read is incomplete. */
+ rc = read(fd, buf, len);
+ while (rc < 0 || cur + rc < len) {
+ if (!rc) {
+ RPRINTF("end-of-file");
+ return -1;
+ }
+ if (rc < 0 && errno != EAGAIN) {
+ RPRINTF("error during read: %s\n", strerror(errno));
+ return -1;
+ }
+ if (rc > 0)
+ cur += rc;
+
+ FD_ZERO(&rfds);
+ FD_SET(fd, &rfds);
+ if (!(rc = select(fd + 1, &rfds, NULL, NULL, &tv))) {
+ RPRINTF("time out during read\n");
+ return -1;
+ } else if (rc < 0) {
+ RPRINTF("error during select: %d\n", errno);
+ return -1;
+ }
+ rc = read(fd, buf + cur, len - cur);
+ }
+ /*
+ RPRINTF("read %d bytes\n", cur + rc);
+ */
+
+ return 0;
+}
+
+static int mwrite(int fd, void* buf, size_t len)
+{
+ fd_set wfds;
+ size_t cur = 0;
+ int rc;
+ struct timeval tv = {
+ .tv_sec = 0,
+ .tv_usec = NET_TIMEOUT * 1000
+ };
+
+ if (!len)
+ return 0;
+
+ /* read first. Only select if read is incomplete. */
+ rc = write(fd, buf, len);
+ while (rc < 0 || cur + rc < len) {
+ if (!rc) {
+ RPRINTF("end-of-file");
+ return -1;
+ }
+ if (rc < 0 && errno != EAGAIN) {
+ RPRINTF("error during write: %s\n", strerror(errno));
+ return -1;
+ }
+ if (rc > 0)
+ cur += rc;
+
+ FD_ZERO(&wfds);
+ FD_SET(fd, &wfds);
+ if (!(rc = select(fd + 1, NULL, &wfds, NULL, &tv))) {
+ RPRINTF("time out during write\n");
+ return -1;
+ } else if (rc < 0) {
+ RPRINTF("error during select: %d\n", errno);
+ return -1;
+ }
+ rc = write(fd, buf + cur, len - cur);
+ }
+ /*
+ RPRINTF("wrote %d bytes\n", cur + rc);
+ */
+
+ return 0;
+ FD_ZERO(&wfds);
+ FD_SET(fd, &wfds);
+ select(fd + 1, NULL, &wfds, NULL, &tv);
+}
+
+
+static void inline close_stream_fd(struct tdremus_state *s)
+{
+ /* XXX: -2 is magic. replace with macro perhaps? */
+ tapdisk_server_unregister_event(s->stream_fd.id);
+ close(s->stream_fd.fd);
+ s->stream_fd.fd = -2;
+}
+
+/* primary functions */
+static void remus_client_event(event_id_t, char mode, void *private);
+static void remus_connect_event(event_id_t id, char mode, void *private);
+static void remus_retry_connect_event(event_id_t id, char mode, void *private);
+
+static int primary_do_connect(struct tdremus_state *state)
+{
+ event_id_t id;
+ int fd;
+ int rc;
+ int flags;
+
+ RPRINTF("client connecting to %s:%d...\n", inet_ntoa(state->sa.sin_addr),
ntohs(state->sa.sin_port));
+
+ if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
+ RPRINTF("could not create client socket: %d\n", errno);
+ return -1;
+ }
+
+ /* make socket nonblocking */
+ if ((flags = fcntl(fd, F_GETFL, 0)) == -1)
+ flags = 0;
+ if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
+ return -1;
+
+ /* once we have created the socket and populated the address, we can now
start
+ * our non-blocking connect. rather than duplicating code we trigger a
timeout
+ * on the socket fd, which calls out nonblocking connect code
+ */
+ if((id = tapdisk_server_register_event(SCHEDULER_POLL_TIMEOUT, fd, 0,
remus_retry_connect_event, state)) < 0) {
+ RPRINTF("error registering timeout client connection event handler: %s\n",
strerror(id));
+ /* TODO: we leak a fd here */
+ return -1;
+ }
+ state->stream_fd.fd = fd;
+ state->stream_fd.id = id;
+ return 0;
+}
+
+static int primary_blocking_connect(struct tdremus_state *state)
+{
+ int fd;
+ int id;
+ int rc;
+ int flags;
+
+ RPRINTF("client connecting to %s:%d...\n", inet_ntoa(state->sa.sin_addr),
ntohs(state->sa.sin_port));
+
+ if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
+ RPRINTF("could not create client socket: %d\n", errno);
+ return -1;
+ }
+
+ do {
+ if ((rc = connect(fd, &state->sa, sizeof(state->sa))) < 0) {
+ if (errno == ECONNREFUSED) {
+ RPRINTF("connection refused -- retrying in 1 second\n");
+ sleep(1);
+ } else {
+ RPRINTF("connection failed: %d\n", errno);
+ close(fd);
+ return -1;
+ }
+ }
+ } while (rc < 0);
+
+ RPRINTF("client connected\n");
+
+ /* make socket nonblocking */
+ if ((flags = fcntl(fd, F_GETFL, 0)) == -1)
+ flags = 0;
+ if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
+ {
+ RPRINTF("error making socket nonblocking\n");
+ close(fd);
+ return -1;
+ }
+
+ if((id = tapdisk_server_register_event(SCHEDULER_POLL_READ_FD, fd, 0,
remus_client_event, state)) < 0) {
+ RPRINTF("error registering client event handler: %s\n", strerror(id));
+ close(fd);
+ return -1;
+ }
+
+ state->stream_fd.fd = fd;
+ state->stream_fd.id = id;
+ return 0;
+}
+
+/* on read, just pass request through */
+static void primary_queue_read(td_driver_t *driver, td_request_t treq)
+{
+ /* just pass read through */
+ td_forward_request(treq);
+}
+
+/* TODO:
+ * The primary uses mwrite() to write the contents of a write request to the
+ * backup. This effectively blocks until all data has been copied into a system
+ * buffer or a timeout has occured. We may wish to instead use tapdisk's
+ * nonblocking i/o interface, tapdisk_server_register_event(), to set timeouts
+ * and write data in an asynchronous fashion.
+ */
+static void primary_queue_write(td_driver_t *driver, td_request_t treq)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ char header[sizeof(uint32_t) + sizeof(uint64_t)];
+ uint32_t *sectors = (uint32_t *)header;
+ uint64_t *sector = (uint64_t *)(header + sizeof(uint32_t));
+
+ // RPRINTF("write: stream_fd.fd: %d\n", s->stream_fd.fd);
+
+ /* -1 means we haven't connected yet, -2 means the connection was lost */
+ if(s->stream_fd.fd == -1) {
+ RPRINTF("connecting to backup...\n");
+ primary_blocking_connect(s);
+ }
+
+ *sectors = treq.secs;
+ *sector = treq.sec;
+
+ if (mwrite(s->stream_fd.fd, TDREMUS_WRITE, strlen(TDREMUS_WRITE)) < 0)
+ goto fail;
+ if (mwrite(s->stream_fd.fd, header, sizeof(header)) < 0)
+ goto fail;
+
+ if (mwrite(s->stream_fd.fd, treq.buf, treq.secs *
driver->info.sector_size) < 0)
+ goto fail;
+
+ td_forward_request(treq);
+
+ return;
+
+ fail:
+ /* switch to unprotected mode and tell tapdisk to retry */
+ RPRINTF("write request replication failed, switching to unprotected mode");
+ switch_mode(s->tdremus_driver, mode_unprotected);
+ td_complete_request(treq, -EBUSY);
+}
+
+
+static int client_flush(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ // RPRINTF("committing output\n");
+
+ if (s->stream_fd.fd == -1)
+ /* connection not yet established, nothing to flush */
+ return 0;
+
+ if (mwrite(s->stream_fd.fd, TDREMUS_COMMIT, strlen(TDREMUS_COMMIT)) < 0) {
+ RPRINTF("error flushing output");
+ close_stream_fd(s);
+ return -1;
+ }
+
+ return 0;
+}
+
+static int primary_start(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ RPRINTF("activating client mode\n");
+
+ tapdisk_remus.td_queue_read = primary_queue_read;
+ tapdisk_remus.td_queue_write = primary_queue_write;
+ s->queue_flush = client_flush;
+
+ s->stream_fd.fd = -1;
+ s->stream_fd.id = -1;
+
+ return 0;
+}
+
+/* timeout callback */
+static void remus_retry_connect_event(event_id_t id, char mode, void *private)
+{
+ struct tdremus_state *s = (struct tdremus_state *)private;
+
+ /* do a non-blocking connect */
+ if (connect(s->stream_fd.fd, &s->sa, sizeof(s->sa)) && errno != EINPROGRESS)
{
+ if(errno == ECONNREFUSED || errno == ENETUNREACH || errno == EAGAIN ||
errno == ECONNABORTED)
+ {
+ /* try again in a second */
+ tapdisk_server_unregister_event(s->stream_fd.id);
+ if((id = tapdisk_server_register_event(SCHEDULER_POLL_TIMEOUT,
s->stream_fd.fd, REMUS_CONNRETRY_TIMEOUT, remus_retry_connect_event, s)) < 0) {
+ RPRINTF("error registering timeout client connection event handler:
%s\n", strerror(id));
+ return;
+ }
+ s->stream_fd.id = id;
+ }
+ else
+ {
+ /* not recoverable */
+ RPRINTF("error connection to server %s\n", strerror(errno));
+ return;
+ }
+ }
+ else
+ {
+ /* the connect returned EINPROGRESS (nonblocking connect) we must wait for
the fd to be writeable to determine if the connect worked */
+
+ tapdisk_server_unregister_event(s->stream_fd.id);
+ if((id = tapdisk_server_register_event(SCHEDULER_POLL_WRITE_FD,
s->stream_fd.fd, 0, remus_connect_event, s)) < 0) {
+ RPRINTF("error registering client connection event handler: %s\n",
strerror(id));
+ return;
+ }
+ s->stream_fd.id = id;
+ }
+}
+
+/* callback when nonblocking connect() is finished */
+/* called only by primary in unprotected state */
+static void remus_connect_event(event_id_t id, char mode, void *private)
+{
+ int socket_errno;
+ socklen_t socket_errno_size;
+ struct tdremus_state *s = (struct tdremus_state *)private;
+
+ /* check to se if the connect succeeded */
+ socket_errno_size = sizeof(socket_errno);
+ if (getsockopt(s->stream_fd.fd, SOL_SOCKET, SO_ERROR, &socket_errno,
&socket_errno_size)) {
+ RPRINTF("error getting socket errno\n");
+ return;
+ }
+
+ RPRINTF("socket connect returned %d\n", socket_errno);
+
+ if(socket_errno)
+ {
+ /* the connect did not succeed */
+
+ if(socket_errno == ECONNREFUSED || socket_errno == ENETUNREACH ||
socket_errno == ETIMEDOUT
+ || socket_errno == ECONNABORTED || socket_errno == EAGAIN)
+ {
+ /* we can probably assume that the backup is down. just try again later
*/
+ tapdisk_server_unregister_event(s->stream_fd.id);
+ if((id = tapdisk_server_register_event(SCHEDULER_POLL_TIMEOUT,
s->stream_fd.fd, REMUS_CONNRETRY_TIMEOUT, remus_retry_connect_event, s)) < 0) {
+ RPRINTF("error registering timeout client connection event handler:
%s\n", strerror(id));
+ return;
+ }
+ s->stream_fd.id = id;
+ }
+ else
+ {
+ RPRINTF("socket connect returned %d, giving up\n", socket_errno);
+ }
+ }
+ else
+ {
+ /* the connect succeeded */
+
+ /* unregister this function and register a new event handler */
+ tapdisk_server_unregister_event(s->stream_fd.id);
+ if((id = tapdisk_server_register_event(SCHEDULER_POLL_READ_FD,
s->stream_fd.fd, 0, remus_client_event, s)) < 0) {
+ RPRINTF("error registering client event handler: %s\n", strerror(id));
+ return;
+ }
+ s->stream_fd.id = id;
+
+ /* switch from unprotected to protected client */
+ switch_mode(s->tdremus_driver, mode_primary);
+ }
+}
+
+
+/* we install this event handler on the primary once we have connected to the
backup */
+/* wait for "done" message to commit checkpoint */
+static void remus_client_event(event_id_t id, char mode, void *private)
+{
+ struct tdremus_state *s = (struct tdremus_state *)private;
+ char req[5];
+ int rc;
+
+ if (mread(s->stream_fd.fd, req, sizeof(req) - 1) < 0) {
+ /* replication stream closed or otherwise broken (timeout, reset, &c) */
+ RPRINTF("error reading from backup\n");
+ close_stream_fd(s);
+ return;
+ }
+
+ req[4] = '\0';
+
+ if (!strcmp(req, TDREMUS_DONE))
+ /* checkpoint committed, inform msg_fd */
+ ctl_respond(s, TDREMUS_DONE);
+ else {
+ RPRINTF("received unknown message: %s\n", req);
+ close_stream_fd(s);
+ }
+
+ return;
+}
+
+/* backup functions */
+static void remus_server_event(event_id_t id, char mode, void *private);
+
+/* returns the socket that receives write requests */
+static void remus_server_accept(event_id_t id, char mode, void* private)
+{
+ struct tdremus_state* s = (struct tdremus_state *) private;
+
+ int stream_fd;
+ event_id_t cid;
+
+ /* XXX: add address-based black/white list */
+ if ((stream_fd = accept(s->server_fd.fd, NULL, NULL)) < 0) {
+ RPRINTF("error accepting connection: %d\n", errno);
+ return;
+ }
+
+ /* TODO: check to see if we are already replicating. if so just close the
+ * connection (or do something smarter) */
+ RPRINTF("server accepted connection\n");
+
+ /* add tapdisk event for replication stream */
+ cid = tapdisk_server_register_event(SCHEDULER_POLL_READ_FD, stream_fd, 0,
+ remus_server_event, s);
+
+ if(cid < 0) {
+ RPRINTF("error registering connection event handler: %s\n",
strerror(errno));
+ close(stream_fd);
+ return;
+ }
+
+ /* store replication file descriptor */
+ s->stream_fd.fd = stream_fd;
+ s->stream_fd.id = cid;
+}
+
+/* returns -2 if EADDRNOTAVAIL */
+static int remus_bind(struct tdremus_state* s)
+{
+// struct sockaddr_in sa;
+ int opt;
+ int rc = -1;
+
+ if ((s->server_fd.fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
+ RPRINTF("could not create server socket: %d\n", errno);
+ return rc;
+ }
+ opt = 1;
+ if (setsockopt(s->server_fd.fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt))
< 0)
+ RPRINTF("Error setting REUSEADDR on %d: %d\n", s->server_fd.fd, errno);
+
+ if (bind(s->server_fd.fd, &s->sa, sizeof(s->sa)) < 0) {
+ RPRINTF("could not bind server socket %d to %s:%d: %d %s\n",
s->server_fd.fd,
+ inet_ntoa(s->sa.sin_addr), ntohs(s->sa.sin_port), errno,
strerror(errno));
+ if (errno != EADDRINUSE)
+ rc = -2;
+ goto err_sfd;
+ }
+ if (listen(s->server_fd.fd, 10)) {
+ RPRINTF("could not listen on socket: %d\n", errno);
+ goto err_sfd;
+ }
+
+ /* The socket s now bound to the address and listening so we may now register
+ * the fd with tapdisk */
+
+ if((s->server_fd.id = tapdisk_server_register_event(SCHEDULER_POLL_READ_FD,
+ s->server_fd.fd, 0,
+ remus_server_accept, s))
< 0) {
+ RPRINTF("error registering server connection event handler: %s",
+ strerror(s->server_fd.id));
+ goto err_sfd;
+ }
+
+ return 0;
+
+ err_sfd:
+ close(s->server_fd.fd);
+ s->server_fd.fd = -1;
+
+ return rc;
+}
+
+/* wait for latest checkpoint to be applied */
+static inline int server_writes_inflight(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ if (!s->ramdisk.inflight && !s->ramdisk.prev)
+ return 0;
+
+ return 1;
+}
+
+/* Due to block device prefetching this code may be called on the server side
+ * during normal replication. In this case we must return EBUSY, otherwise the
+ * domain may be started with stale data.
+ */
+void backup_queue_read(td_driver_t *driver, td_request_t treq)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ if(!remus_image)
+ remus_image = treq.image;
+
+#if 0
+ /* due to prefetching, we must return EBUSY on server reads. This
+ * maintains a consistent disk image */
+ td_complete_request(treq, -EBUSY);
+#else
+ /* what exactly is the race that requires the response above? */
+ td_forward_request(treq);
+#endif
+}
+
+/* see above */
+void backup_queue_write(td_driver_t *driver, td_request_t treq)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ /* on a server write, we know the domain has failed over. we must change our
+ * state to unprotected and then have the unprotected queue_write function
+ * handle the write
+ */
+
+ switch_mode(driver, mode_unprotected);
+ /* TODO: call the appropriate write function rather than return EBUSY */
+ td_complete_request(treq, -EBUSY);
+}
+
+static int backup_start(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+ int fd;
+
+ if (ramdisk_start(driver) < 0)
+ return -1;
+
+ tapdisk_remus.td_queue_read = backup_queue_read;
+ tapdisk_remus.td_queue_write = backup_queue_write;
+ /* TODO set flush function */
+ return 0;
+}
+
+static int server_do_wreq(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+ static tdremus_wire_t twreq;
+ char buf[4096];
+ int len, rc;
+
+ char header[sizeof(uint32_t) + sizeof(uint64_t)];
+ uint32_t *sectors = (uint32_t *) header;
+ uint64_t *sector = (uint64_t *) &header[sizeof(uint32_t)];
+
+ // RPRINTF("received write request\n");
+
+ if (mread(s->stream_fd.fd, header, sizeof(header)) < 0)
+ goto err;
+
+ len = *sectors * driver->info.sector_size;
+
+ //RPRINTF("writing %d sectors (%d bytes) starting at %" PRIu64 "\n",
*sectors, len,
+ // *sector);
+
+ if (len > sizeof(buf)) {
+ /* freak out! */
+ RPRINTF("write request too large: %d/%u\n", len, (unsigned)sizeof(buf));
+ return -1;
+ }
+
+ if (mread(s->stream_fd.fd, buf, len) < 0)
+ goto err;
+
+ if (ramdisk_write(&s->ramdisk, *sector, *sectors, buf) < 0)
+ goto err;
+
+ return 0;
+
+ err:
+ /* should start failover */
+ RPRINTF("backup write request error\n");
+ close_stream_fd(s);
+
+ return -1;
+}
+
+static int server_do_sreq(td_driver_t *driver)
+{
+ /*
+ RPRINTF("submit request received\n");
+ */
+
+ return 0;
+}
+
+/* at this point, the server can start applying the most recent
+ * ramdisk. */
+static int server_do_creq(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ // RPRINTF("committing buffer\n");
+
+ ramdisk_start_flush(driver);
+
+ /* XXX this message should not be sent until flush completes! */
+ if (write(s->stream_fd.fd, TDREMUS_DONE, strlen(TDREMUS_DONE)) != 4)
+ return -1;
+
+ return 0;
+}
+
+
+/* called when data is pending in s->rfd */
+static void remus_server_event(event_id_t id, char mode, void *private)
+{
+ struct tdremus_state *s = (struct tdremus_state *)private;
+ td_driver_t *driver = s->tdremus_driver;
+ char req[5];
+
+ // RPRINTF("replication data waiting\n");
+
+ /* TODO: add a get_connection_by_event_id() function.
+ * for now we can assume that the fd is s->stream_fd */
+
+ if (mread(s->stream_fd.fd, req, sizeof(req) - 1) < 0) {
+ RPRINTF("error reading server event, activating backup\n");
+ switch_mode(driver, mode_unprotected);
+ return;
+ }
+
+ req[4] = '\0';
+
+ if (!strcmp(req, TDREMUS_WRITE))
+ server_do_wreq(driver);
+ else if (!strcmp(req, TDREMUS_SUBMIT))
+ server_do_sreq(driver);
+ else if (!strcmp(req, TDREMUS_COMMIT))
+ server_do_creq(driver);
+ else
+ RPRINTF("unknown request received: %s\n", req);
+
+ return;
+
+}
+
+/* unprotected */
+
+void unprotected_queue_read(td_driver_t *driver, td_request_t treq)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ /* wait for previous ramdisk to flush before servicing reads */
+ if (server_writes_inflight(driver)) {
+ /* for now lets just return EBUSY. if this becomes an issue we can
+ * do something smarter */
+ td_complete_request(treq, -EBUSY);
+ }
+ else {
+ /* here we just pass reads through */
+ td_forward_request(treq);
+ }
+}
+
+/* For a recoverable remus solution we need to log unprotected writes here */
+void unprotected_queue_write(td_driver_t *driver, td_request_t treq)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ /* wait for previous ramdisk to flush */
+ if (server_writes_inflight(driver)) {
+ RPRINTF("queue_write: waiting for queue to drain");
+ td_complete_request(treq, -EBUSY);
+ }
+ else {
+ // RPRINTF("servicing write request on backup\n");
+ td_forward_request(treq);
+ }
+}
+
+static int unprotected_start(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ RPRINTF("failure detected, activating passthrough\n");
+
+ /* close the server socket */
+ close_stream_fd(s);
+
+ /* unregister the replication stream */
+ tapdisk_server_unregister_event(s->server_fd.id);
+
+ /* close the replication stream */
+ close(s->server_fd.fd);
+ s->server_fd.fd = -1;
+
+ /* install the unprotected read/write handlers */
+ tapdisk_remus.td_queue_read = unprotected_queue_read;
+ tapdisk_remus.td_queue_write = unprotected_queue_write;
+
+ return 0;
+}
+
+
+/* control */
+
+static inline int resolve_address(const char* addr, struct in_addr* ia)
+{
+ struct hostent* he;
+ uint32_t ip;
+
+ if (!(he = gethostbyname(addr))) {
+ RPRINTF("error resolving %s: %d\n", addr, h_errno);
+ return -1;
+ }
+
+ if (!he->h_addr_list[0]) {
+ RPRINTF("no address found for %s\n", addr);
+ return -1;
+ }
+
+ /* network byte order */
+ ip = *((uint32_t**)he->h_addr_list)[0];
+ ia->s_addr = ip;
+
+ return 0;
+}
+
+static int get_args(td_driver_t *driver, const char* name)
+{
+ struct tdremus_state *state = (struct tdremus_state *)driver->data;
+ char* host;
+ char* port;
+// char* driver_str;
+// char* parent;
+// int type;
+// char* path;
+// unsigned long ulport;
+// int i;
+// struct sockaddr_in server_addr_in;
+
+ int gai_status;
+ int valid_addr;
+ struct addrinfo gai_hints;
+ struct addrinfo *servinfo, *servinfo_itr;
+
+ memset(&gai_hints, 0, sizeof gai_hints);
+ gai_hints.ai_family = AF_UNSPEC;
+ gai_hints.ai_socktype = SOCK_STREAM;
+
+ port = strchr(name, ':');
+ if (!port) {
+ RPRINTF("missing host in %s\n", name);
+ return -ENOENT;
+ }
+ if (!(host = strndup(name, port - name))) {
+ RPRINTF("unable to allocate host\n");
+ return -ENOMEM;
+ }
+ port++;
+
+ if ((gai_status = getaddrinfo(host, port, &gai_hints, &servinfo)) != 0) {
+ RPRINTF("getaddrinfo error: %s\n", gai_strerror(gai_status));
+ return -ENOENT;
+ }
+
+ /* TODO: do something smarter here */
+ valid_addr = 0;
+ for(servinfo_itr = servinfo; servinfo_itr != NULL; servinfo_itr =
servinfo_itr->ai_next) {
+ void *addr;
+ char *ipver;
+
+ if (servinfo_itr->ai_family == AF_INET) {
+ valid_addr = 1;
+ memset(&state->sa, 0, sizeof(state->sa));
+ state->sa = *(struct sockaddr_in *)servinfo_itr->ai_addr;
+ break;
+ }
+ }
+ freeaddrinfo(servinfo);
+
+ if (!valid_addr)
+ return -ENOENT;
+
+ RPRINTF("host: %s, port: %d\n", inet_ntoa(state->sa.sin_addr),
ntohs(state->sa.sin_port));
+
+ return 0;
+}
+
+static int switch_mode(td_driver_t *driver, enum tdremus_mode mode)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+ int rc;
+
+ if (mode == s->mode)
+ return 0;
+
+ if (s->queue_flush)
+ if ((rc = s->queue_flush(driver)) < 0) {
+ // fall back to unprotected mode on error
+ RPRINTF("switch_mode: error flushing queue (old: %d, new: %d)",
s->mode, mode);
+ mode = mode_unprotected;
+ }
+
+ if (mode == mode_unprotected)
+ rc = unprotected_start(driver);
+ else if (mode == mode_primary)
+ rc = primary_start(driver);
+ else if (mode == mode_backup)
+ rc = backup_start(driver);
+ else {
+ RPRINTF("unknown mode requested: %d\n", mode);
+ rc = -1;
+ }
+
+ if (!rc)
+ s->mode = mode;
+
+ return rc;
+}
+
+static void ctl_request(event_id_t id, char mode, void *private)
+{
+ struct tdremus_state *s = (struct tdremus_state *)private;
+ td_driver_t *driver = s->tdremus_driver;
+ char msg[80];
+ int rc;
+
+ // RPRINTF("data waiting on control fifo\n");
+
+ if (!(rc = read(s->ctl_fd.fd, msg, sizeof(msg) - 1 /* append nul */))) {
+ RPRINTF("0-byte read received, reopening FIFO\n");
+ /*TODO: we may have to unregister/re-register with tapdisk_server */
+ close(s->ctl_fd.fd);
+ RPRINTF("FIFO closed\n");
+ if ((s->ctl_fd.fd = open(s->ctl_path, O_RDWR)) < 0) {
+ RPRINTF("error reopening FIFO: %d\n", errno);
+ }
+ return;
+ }
+
+ if (rc < 0) {
+ RPRINTF("error reading from FIFO: %d\n", errno);
+ return;
+ }
+
+ /* TODO: need to get driver somehow */
+ msg[rc] = '\0';
+ if (!strncmp(msg, "flush", 5)) {
+ if (s->queue_flush)
+ if ((rc = s->queue_flush(driver))) {
+ RPRINTF("error passing flush request to backup");
+ ctl_respond(s, TDREMUS_FAIL);
+ }
+ } else {
+ RPRINTF("unknown command: %s\n", msg);
+ }
+}
+
+static int ctl_respond(struct tdremus_state *s, const char *response)
+{
+ int rc;
+
+ if ((rc = write(s->msg_fd.fd, response, strlen(response))) < 0) {
+ RPRINTF("error writing notification: %d\n", errno);
+ close(s->msg_fd.fd);
+ if ((s->msg_fd.fd = open(s->msg_path, O_RDWR)) < 0)
+ RPRINTF("error reopening FIFO: %d\n", errno);
+ }
+
+ return rc;
+}
+
+/* must be called after the underlying driver has been initialized */
+static int ctl_open(td_driver_t *driver, const char* name)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+ int i, l;
+
+ /* first we must ensure that BLKTAP_CTRL_DIR exists */
+ if (mkdir(BLKTAP_CTRL_DIR, 0755) && errno != EEXIST)
+ {
+ DPRINTF("error creating directory %s: %d\n", BLKTAP_CTRL_DIR, errno);
+ return -1;
+ }
+
+ /* use the device name to create the control fifo path */
+ if (asprintf(&s->ctl_path, BLKTAP_CTRL_DIR "/remus_%s", name) < 0)
+ return -1;
+ /* scrub fifo pathname */
+ for (i = strlen(BLKTAP_CTRL_DIR) + 1, l = strlen(s->ctl_path); i < l; i++) {
+ if (strchr(":/", s->ctl_path[i]))
+ s->ctl_path[i] = '_';
+ }
+ if (asprintf(&s->msg_path, "%s.msg", s->ctl_path) < 0)
+ goto err_ctlfifo;
+
+ if (mkfifo(s->ctl_path, S_IRWXU|S_IRWXG|S_IRWXO) && errno != EEXIST) {
+ RPRINTF("error creating control FIFO %s: %d\n", s->ctl_path, errno);
+ goto err_msgfifo;
+ }
+
+ if (mkfifo(s->msg_path, S_IRWXU|S_IRWXG|S_IRWXO) && errno != EEXIST) {
+ RPRINTF("error creating message FIFO %s: %d\n", s->msg_path, errno);
+ goto err_msgfifo;
+ }
+
+ /* RDWR so that fd doesn't block select when no writer is present */
+ if ((s->ctl_fd.fd = open(s->ctl_path, O_RDWR)) < 0) {
+ RPRINTF("error opening control FIFO %s: %d\n", s->ctl_path, errno);
+ goto err_msgfifo;
+ }
+
+ if ((s->msg_fd.fd = open(s->msg_path, O_RDWR)) < 0) {
+ RPRINTF("error opening message FIFO %s: %d\n", s->msg_path, errno);
+ goto err_openctlfifo;
+ }
+
+ RPRINTF("control FIFO %s\n", s->ctl_path);
+ RPRINTF("message FIFO %s\n", s->msg_path);
+
+ return 0;
+
+ err_openctlfifo:
+ close(s->ctl_fd.fd);
+ err_msgfifo:
+ free(s->msg_path);
+ s->msg_path = NULL;
+ err_ctlfifo:
+ free(s->ctl_path);
+ s->ctl_path = NULL;
+ return -1;
+}
+
+static void ctl_close(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+
+ /* TODO: close *all* connections */
+
+ if(s->ctl_fd.fd)
+ close(s->ctl_fd.fd);
+
+ if (s->ctl_path) {
+ unlink(s->ctl_path);
+ free(s->ctl_path);
+ s->ctl_path = NULL;
+ }
+ if (s->msg_path) {
+ unlink(s->msg_path);
+ free(s->msg_path);
+ s->msg_path = NULL;
+ }
+}
+
+static int ctl_register(struct tdremus_state *s)
+{
+ RPRINTF("registering ctl fifo\n");
+
+ /* register ctl fd */
+ s->ctl_fd.id = tapdisk_server_register_event(SCHEDULER_POLL_READ_FD,
s->ctl_fd.fd, 0, ctl_request, s);
+
+ if (s->ctl_fd.id < 0) {
+ RPRINTF("error registering ctrl FIFO %s: %d\n", s->ctl_path, s->ctl_fd.id);
+ return -1;
+ }
+
+ return 0;
+}
+
+/* interface */
+
+static int tdremus_open(td_driver_t *driver, const char *name,
+ td_flag_t flags)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+ int rc;
+
+ RPRINTF("opening %s\n", name);
+
+ /* first we need to get the underlying vbd for this driver stack. To do so we
+ * need to know the vbd's id. Fortunately, for tapdisk2 this is hard-coded as
+ * 0 (see tapdisk2.c)
+ */
+ device_vbd = tapdisk_server_get_vbd(0);
+
+ memset(s, 0, sizeof(*s));
+ s->server_fd.fd = -1;
+ s->stream_fd.fd = -1;
+ s->ctl_fd.fd = -1;
+ s->msg_fd.fd = -1;
+
+ /* TODO: this is only needed so that the server can send writes down
+ * the driver stack from the stream_fd event handler */
+ s->tdremus_driver = driver;
+
+ /* parse name to get info etc */
+ if ((rc = get_args(driver, name)))
+ return rc;
+
+ if ((rc = ctl_open(driver, name))) {
+ RPRINTF("error setting up control channel\n");
+ free(s->driver_data);
+ return rc;
+ }
+
+ if ((rc = ctl_register(s))) {
+ RPRINTF("error registering control channel\n");
+ free(s->driver_data);
+ return rc;
+ }
+
+ if (!(rc = remus_bind(s)))
+ rc = switch_mode(driver, mode_backup);
+ else if (rc == -2)
+ rc = switch_mode(driver, mode_primary);
+
+ if (!rc)
+ return 0;
+
+ tdremus_close(driver);
+ return -EIO;
+}
+
+static int tdremus_close(td_driver_t *driver)
+{
+ struct tdremus_state *s = (struct tdremus_state *)driver->data;
+ int rc;
+
+ RPRINTF("closing\n");
+
+ if (s->driver_data) {
+ free(s->driver_data);
+ s->driver_data = NULL;
+ }
+ if (s->server_fd.fd >= 0) {
+ close(s->server_fd.fd);
+ s->server_fd.fd = -1;
+ }
+ if (s->stream_fd.fd >= 0)
+ close_stream_fd(s);
+
+ ctl_close(driver);
+
+ return rc;
+}
+
+static int tdremus_get_parent_id(td_driver_t *driver, td_disk_id_t *id)
+{
+ /* we shouldn't have a parent... for now */
+ return -EINVAL;
+}
+
+static int tdremus_validate_parent(td_driver_t *driver,
+ td_driver_t *pdriver, td_flag_t flags)
+{
+ return 0;
+}
+
+struct tap_disk tapdisk_remus = {
+ .disk_type = "tapdisk_remus",
+ .private_data_size = sizeof(struct tdremus_state),
+ .td_open = tdremus_open,
+ .td_queue_read = unprotected_queue_read,
+ .td_queue_write = unprotected_queue_write,
+ .td_close = tdremus_close,
+ .td_get_parent_id = tdremus_get_parent_id,
+ .td_validate_parent = tdremus_validate_parent,
+ .td_debug = NULL,
+};
diff --git a/tools/blktap2/drivers/disktypes.h
b/tools/blktap2/drivers/disktypes.h
--- a/tools/blktap2/drivers/disktypes.h
+++ b/tools/blktap2/drivers/disktypes.h
@@ -49,6 +49,7 @@
extern struct tap_disk tapdisk_qcow;
extern struct tap_disk tapdisk_block_cache;
extern struct tap_disk tapdisk_log;
+extern struct tap_disk tapdisk_remus;
#define MAX_DISK_TYPES 20
@@ -61,6 +62,7 @@
#define DISK_TYPE_QCOW 6
#define DISK_TYPE_BLOCK_CACHE 7
#define DISK_TYPE_LOG 9
+#define DISK_TYPE_REMUS 10
/*Define Individual Disk Parameters here */
static disk_info_t null_disk = {
@@ -167,6 +169,16 @@
#endif
};
+static disk_info_t remus_disk = {
+ DISK_TYPE_REMUS,
+ "remus disk replicator (remus)",
+ "remus",
+ 0,
+#ifdef TAPDISK
+ &tapdisk_remus,
+#endif
+};
+
/*Main disk info array */
static disk_info_t *dtypes[] = {
&aio_disk,
@@ -179,6 +191,7 @@
&block_cache_disk,
&null_disk,
&log_disk,
+ &remus_disk,
};
#endif
diff --git a/tools/blktap2/drivers/hashtable.c
b/tools/blktap2/drivers/hashtable.c
new file mode 100644
--- /dev/null
+++ b/tools/blktap2/drivers/hashtable.c
@@ -0,0 +1,274 @@
+/* Copyright (C) 2004 Christopher Clark <firstname.lastname@xxxxxxxxxxxx> */
+
+#include "hashtable.h"
+#include "hashtable_private.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+
+/*
+Credit for primes table: Aaron Krowne
+ http://br.endernet.org/~akrowne/
+ http://planetmath.org/encyclopedia/GoodHashTablePrimes.html
+*/
+static const unsigned int primes[] = {
+53, 97, 193, 389,
+769, 1543, 3079, 6151,
+12289, 24593, 49157, 98317,
+196613, 393241, 786433, 1572869,
+3145739, 6291469, 12582917, 25165843,
+50331653, 100663319, 201326611, 402653189,
+805306457, 1610612741
+};
+const unsigned int prime_table_length = sizeof(primes)/sizeof(primes[0]);
+const float max_load_factor = 0.65;
+
+/*****************************************************************************/
+struct hashtable *
+create_hashtable(unsigned int minsize,
+ unsigned int (*hashf) (void*),
+ int (*eqf) (void*,void*))
+{
+ struct hashtable *h;
+ unsigned int pindex, size = primes[0];
+ /* Check requested hashtable isn't too large */
+ if (minsize > (1u << 30)) return NULL;
+ /* Enforce size as prime */
+ for (pindex=0; pindex < prime_table_length; pindex++) {
+ if (primes[pindex] > minsize) { size = primes[pindex]; break; }
+ }
+ h = (struct hashtable *)malloc(sizeof(struct hashtable));
+ if (NULL == h) return NULL; /*oom*/
+ h->table = (struct entry **)malloc(sizeof(struct entry*) * size);
+ if (NULL == h->table) { free(h); return NULL; } /*oom*/
+ memset(h->table, 0, size * sizeof(struct entry *));
+ h->tablelength = size;
+ h->primeindex = pindex;
+ h->entrycount = 0;
+ h->hashfn = hashf;
+ h->eqfn = eqf;
+ h->loadlimit = (unsigned int) ceil(size * max_load_factor);
+ return h;
+}
+
+/*****************************************************************************/
+unsigned int
+hash(struct hashtable *h, void *k)
+{
+ /* Aim to protect against poor hash functions by adding logic here
+ * - logic taken from java 1.4 hashtable source */
+ unsigned int i = h->hashfn(k);
+ i += ~(i << 9);
+ i ^= ((i >> 14) | (i << 18)); /* >>> */
+ i += (i << 4);
+ i ^= ((i >> 10) | (i << 22)); /* >>> */
+ return i;
+}
+
+/*****************************************************************************/
+static int
+hashtable_expand(struct hashtable *h)
+{
+ /* Double the size of the table to accomodate more entries */
+ struct entry **newtable;
+ struct entry *e;
+ struct entry **pE;
+ unsigned int newsize, i, index;
+ /* Check we're not hitting max capacity */
+ if (h->primeindex == (prime_table_length - 1)) return 0;
+ newsize = primes[++(h->primeindex)];
+
+ newtable = (struct entry **)malloc(sizeof(struct entry*) * newsize);
+ if (NULL != newtable)
+ {
+ memset(newtable, 0, newsize * sizeof(struct entry *));
+ /* This algorithm is not 'stable'. ie. it reverses the list
+ * when it transfers entries between the tables */
+ for (i = 0; i < h->tablelength; i++) {
+ while (NULL != (e = h->table[i])) {
+ h->table[i] = e->next;
+ index = indexFor(newsize,e->h);
+ e->next = newtable[index];
+ newtable[index] = e;
+ }
+ }
+ free(h->table);
+ h->table = newtable;
+ }
+ /* Plan B: realloc instead */
+ else
+ {
+ newtable = (struct entry **)
+ realloc(h->table, newsize * sizeof(struct entry *));
+ if (NULL == newtable) { (h->primeindex)--; return 0; }
+ h->table = newtable;
+ memset(newtable[h->tablelength], 0, newsize - h->tablelength);
+ for (i = 0; i < h->tablelength; i++) {
+ for (pE = &(newtable[i]), e = *pE; e != NULL; e = *pE) {
+ index = indexFor(newsize,e->h);
+ if (index == i)
+ {
+ pE = &(e->next);
+ }
+ else
+ {
+ *pE = e->next;
+ e->next = newtable[index];
+ newtable[index] = e;
+ }
+ }
+ }
+ }
+ h->tablelength = newsize;
+ h->loadlimit = (unsigned int) ceil(newsize * max_load_factor);
+ return -1;
+}
+
+/*****************************************************************************/
+unsigned int
+hashtable_count(struct hashtable *h)
+{
+ return h->entrycount;
+}
+
+/*****************************************************************************/
+int
+hashtable_insert(struct hashtable *h, void *k, void *v)
+{
+ /* This method allows duplicate keys - but they shouldn't be used */
+ unsigned int index;
+ struct entry *e;
+ if (++(h->entrycount) > h->loadlimit)
+ {
+ /* Ignore the return value. If expand fails, we should
+ * still try cramming just this value into the existing table
+ * -- we may not have memory for a larger table, but one more
+ * element may be ok. Next time we insert, we'll try expanding again.*/
+ hashtable_expand(h);
+ }
+ e = (struct entry *)malloc(sizeof(struct entry));
+ if (NULL == e) { --(h->entrycount); return 0; } /*oom*/
+ e->h = hash(h,k);
+ index = indexFor(h->tablelength,e->h);
+ e->k = k;
+ e->v = v;
+ e->next = h->table[index];
+ h->table[index] = e;
+ return -1;
+}
+
+/*****************************************************************************/
+void * /* returns value associated with key */
+hashtable_search(struct hashtable *h, void *k)
+{
+ struct entry *e;
+ unsigned int hashvalue, index;
+ hashvalue = hash(h,k);
+ index = indexFor(h->tablelength,hashvalue);
+ e = h->table[index];
+ while (NULL != e)
+ {
+ /* Check hash value to short circuit heavier comparison */
+ if ((hashvalue == e->h) && (h->eqfn(k, e->k))) return e->v;
+ e = e->next;
+ }
+ return NULL;
+}
+
+/*****************************************************************************/
+void * /* returns value associated with key */
+hashtable_remove(struct hashtable *h, void *k)
+{
+ /* TODO: consider compacting the table when the load factor drops enough,
+ * or provide a 'compact' method. */
+
+ struct entry *e;
+ struct entry **pE;
+ void *v;
+ unsigned int hashvalue, index;
+
+ hashvalue = hash(h,k);
+ index = indexFor(h->tablelength,hash(h,k));
+ pE = &(h->table[index]);
+ e = *pE;
+ while (NULL != e)
+ {
+ /* Check hash value to short circuit heavier comparison */
+ if ((hashvalue == e->h) && (h->eqfn(k, e->k)))
+ {
+ *pE = e->next;
+ h->entrycount--;
+ v = e->v;
+ freekey(e->k);
+ free(e);
+ return v;
+ }
+ pE = &(e->next);
+ e = e->next;
+ }
+ return NULL;
+}
+
+/*****************************************************************************/
+/* destroy */
+void
+hashtable_destroy(struct hashtable *h, int free_values)
+{
+ unsigned int i;
+ struct entry *e, *f;
+ struct entry **table = h->table;
+ if (free_values)
+ {
+ for (i = 0; i < h->tablelength; i++)
+ {
+ e = table[i];
+ while (NULL != e)
+ { f = e; e = e->next; freekey(f->k); free(f->v); free(f); }
+ }
+ }
+ else
+ {
+ for (i = 0; i < h->tablelength; i++)
+ {
+ e = table[i];
+ while (NULL != e)
+ { f = e; e = e->next; freekey(f->k); free(f); }
+ }
+ }
+ free(h->table);
+ free(h);
+}
+
+/*
+ * Copyright (c) 2002, Christopher Clark
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of the original author; nor the names of any contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
diff --git a/tools/blktap2/drivers/hashtable_itr.c
b/tools/blktap2/drivers/hashtable_itr.c
new file mode 100644
--- /dev/null
+++ b/tools/blktap2/drivers/hashtable_itr.c
@@ -0,0 +1,188 @@
+/* Copyright (C) 2002, 2004 Christopher Clark
<firstname.lastname@xxxxxxxxxxxx> */
+
+#include "hashtable.h"
+#include "hashtable_private.h"
+#include "hashtable_itr.h"
+#include <stdlib.h> /* defines NULL */
+
+/*****************************************************************************/
+/* hashtable_iterator - iterator constructor */
+
+struct hashtable_itr *
+hashtable_iterator(struct hashtable *h)
+{
+ unsigned int i, tablelength;
+ struct hashtable_itr *itr = (struct hashtable_itr *)
+ malloc(sizeof(struct hashtable_itr));
+ if (NULL == itr) return NULL;
+ itr->h = h;
+ itr->e = NULL;
+ itr->parent = NULL;
+ tablelength = h->tablelength;
+ itr->index = tablelength;
+ if (0 == h->entrycount) return itr;
+
+ for (i = 0; i < tablelength; i++)
+ {
+ if (NULL != h->table[i])
+ {
+ itr->e = h->table[i];
+ itr->index = i;
+ break;
+ }
+ }
+ return itr;
+}
+
+/*****************************************************************************/
+/* key - return the key of the (key,value) pair at the current position */
+/* value - return the value of the (key,value) pair at the current position
*/
+
+void *
+hashtable_iterator_key(struct hashtable_itr *i)
+{ return i->e->k; }
+
+void *
+hashtable_iterator_value(struct hashtable_itr *i)
+{ return i->e->v; }
+
+/*****************************************************************************/
+/* advance - advance the iterator to the next element
+ * returns zero if advanced to end of table */
+
+int
+hashtable_iterator_advance(struct hashtable_itr *itr)
+{
+ unsigned int j,tablelength;
+ struct entry **table;
+ struct entry *next;
+ if (NULL == itr->e) return 0; /* stupidity check */
+
+ next = itr->e->next;
+ if (NULL != next)
+ {
+ itr->parent = itr->e;
+ itr->e = next;
+ return -1;
+ }
+ tablelength = itr->h->tablelength;
+ itr->parent = NULL;
+ if (tablelength <= (j = ++(itr->index)))
+ {
+ itr->e = NULL;
+ return 0;
+ }
+ table = itr->h->table;
+ while (NULL == (next = table[j]))
+ {
+ if (++j >= tablelength)
+ {
+ itr->index = tablelength;
+ itr->e = NULL;
+ return 0;
+ }
+ }
+ itr->index = j;
+ itr->e = next;
+ return -1;
+}
+
+/*****************************************************************************/
+/* remove - remove the entry at the current iterator position
+ * and advance the iterator, if there is a successive
+ * element.
+ * If you want the value, read it before you remove:
+ * beware memory leaks if you don't.
+ * Returns zero if end of iteration. */
+
+int
+hashtable_iterator_remove(struct hashtable_itr *itr)
+{
+ struct entry *remember_e, *remember_parent;
+ int ret;
+
+ /* Do the removal */
+ if (NULL == (itr->parent))
+ {
+ /* element is head of a chain */
+ itr->h->table[itr->index] = itr->e->next;
+ } else {
+ /* element is mid-chain */
+ itr->parent->next = itr->e->next;
+ }
+ /* itr->e is now outside the hashtable */
+ remember_e = itr->e;
+ itr->h->entrycount--;
+ freekey(remember_e->k);
+
+ /* Advance the iterator, correcting the parent */
+ remember_parent = itr->parent;
+ ret = hashtable_iterator_advance(itr);
+ if (itr->parent == remember_e) { itr->parent = remember_parent; }
+ free(remember_e);
+ return ret;
+}
+
+/*****************************************************************************/
+int /* returns zero if not found */
+hashtable_iterator_search(struct hashtable_itr *itr,
+ struct hashtable *h, void *k)
+{
+ struct entry *e, *parent;
+ unsigned int hashvalue, index;
+
+ hashvalue = hash(h,k);
+ index = indexFor(h->tablelength,hashvalue);
+
+ e = h->table[index];
+ parent = NULL;
+ while (NULL != e)
+ {
+ /* Check hash value to short circuit heavier comparison */
+ if ((hashvalue == e->h) && (h->eqfn(k, e->k)))
+ {
+ itr->index = index;
+ itr->e = e;
+ itr->parent = parent;
+ itr->h = h;
+ return -1;
+ }
+ parent = e;
+ e = e->next;
+ }
+ return 0;
+}
+
+
+/*
+ * Copyright (c) 2002, 2004, Christopher Clark
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of the original author; nor the names of any contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
diff --git a/tools/blktap2/drivers/hashtable_itr.h
b/tools/blktap2/drivers/hashtable_itr.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap2/drivers/hashtable_itr.h
@@ -0,0 +1,112 @@
+/* Copyright (C) 2002, 2004 Christopher Clark
<firstname.lastname@xxxxxxxxxxxx> */
+
+#ifndef __HASHTABLE_ITR_CWC22__
+#define __HASHTABLE_ITR_CWC22__
+#include "hashtable.h"
+#include "hashtable_private.h" /* needed to enable inlining */
+
+/*****************************************************************************/
+/* This struct is only concrete here to allow the inlining of two of the
+ * accessor functions. */
+struct hashtable_itr
+{
+ struct hashtable *h;
+ struct entry *e;
+ struct entry *parent;
+ unsigned int index;
+};
+
+
+/*****************************************************************************/
+/* hashtable_iterator
+ */
+
+struct hashtable_itr *
+hashtable_iterator(struct hashtable *h);
+
+/*****************************************************************************/
+/* hashtable_iterator_key
+ * - return the value of the (key,value) pair at the current position */
+
+extern inline void *
+hashtable_iterator_key(struct hashtable_itr *i)
+{
+ return i->e->k;
+}
+
+/*****************************************************************************/
+/* value - return the value of the (key,value) pair at the current position */
+
+extern inline void *
+hashtable_iterator_value(struct hashtable_itr *i)
+{
+ return i->e->v;
+}
+
+/*****************************************************************************/
+/* advance - advance the iterator to the next element
+ * returns zero if advanced to end of table */
+
+int
+hashtable_iterator_advance(struct hashtable_itr *itr);
+
+/*****************************************************************************/
+/* remove - remove current element and advance the iterator to the next element
+ * NB: if you need the value to free it, read it before
+ * removing. ie: beware memory leaks!
+ * returns zero if advanced to end of table */
+
+int
+hashtable_iterator_remove(struct hashtable_itr *itr);
+
+/*****************************************************************************/
+/* search - overwrite the supplied iterator, to point to the entry
+ * matching the supplied key.
+ h points to the hashtable to be searched.
+ * returns zero if not found. */
+int
+hashtable_iterator_search(struct hashtable_itr *itr,
+ struct hashtable *h, void *k);
+
+#define DEFINE_HASHTABLE_ITERATOR_SEARCH(fnname, keytype) \
+int fnname (struct hashtable_itr *i, struct hashtable *h, keytype *k) \
+{ \
+ return (hashtable_iterator_search(i,h,k)); \
+}
+
+
+
+#endif /* __HASHTABLE_ITR_CWC22__*/
+
+/*
+ * Copyright (c) 2002, 2004, Christopher Clark
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of the original author; nor the names of any contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
diff --git a/tools/blktap2/drivers/hashtable_utility.c
b/tools/blktap2/drivers/hashtable_utility.c
new file mode 100644
--- /dev/null
+++ b/tools/blktap2/drivers/hashtable_utility.c
@@ -0,0 +1,71 @@
+/* Copyright (C) 2002 Christopher Clark <firstname.lastname@xxxxxxxxxxxx> */
+
+#include "hashtable.h"
+#include "hashtable_private.h"
+#include "hashtable_utility.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+/*****************************************************************************/
+/* hashtable_change
+ *
+ * function to change the value associated with a key, where there already
+ * exists a value bound to the key in the hashtable.
+ * Source due to Holger Schemel.
+ *
+ * */
+int
+hashtable_change(struct hashtable *h, void *k, void *v)
+{
+ struct entry *e;
+ unsigned int hashvalue, index;
+ hashvalue = hash(h,k);
+ index = indexFor(h->tablelength,hashvalue);
+ e = h->table[index];
+ while (NULL != e)
+ {
+ /* Check hash value to short circuit heavier comparison */
+ if ((hashvalue == e->h) && (h->eqfn(k, e->k)))
+ {
+ free(e->v);
+ e->v = v;
+ return -1;
+ }
+ e = e->next;
+ }
+ return 0;
+}
+
+/*
+ * Copyright (c) 2002, Christopher Clark
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of the original author; nor the names of any contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
diff --git a/tools/blktap2/drivers/hashtable_utility.h
b/tools/blktap2/drivers/hashtable_utility.h
new file mode 100644
--- /dev/null
+++ b/tools/blktap2/drivers/hashtable_utility.h
@@ -0,0 +1,55 @@
+/* Copyright (C) 2002 Christopher Clark <firstname.lastname@xxxxxxxxxxxx> */
+
+#ifndef __HASHTABLE_CWC22_UTILITY_H__
+#define __HASHTABLE_CWC22_UTILITY_H__
+
+/*****************************************************************************
+ * hashtable_change
+ *
+ * function to change the value associated with a key, where there already
+ * exists a value bound to the key in the hashtable.
+ * Source due to Holger Schemel.
+ *
+ * @name hashtable_change
+ * @param h the hashtable
+ * @param key
+ * @param value
+ *
+ */
+int
+hashtable_change(struct hashtable *h, void *k, void *v);
+
+#endif /* __HASHTABLE_CWC22_H__ */
+
+/*
+ * Copyright (c) 2002, Christopher Clark
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of the original author; nor the names of any contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
diff --git a/tools/python/xen/xend/server/BlktapController.py
b/tools/python/xen/xend/server/BlktapController.py
--- a/tools/python/xen/xend/server/BlktapController.py
+++ b/tools/python/xen/xend/server/BlktapController.py
@@ -28,6 +28,7 @@
'ram',
'qcow',
'vhd',
+ 'remus',
]
blktap_disk_types = blktap1_disk_types + blktap2_disk_types
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