#include <sys/socket.h>
#include <sys/un.h>
#include "mdadm.h"
+#include "mdmon.h"
-enum tx_rx_state {
- TX_RX_START,
- TX_RX_SEQ,
- TX_RX_NUM_BYTES,
- TX_RX_BUF,
- TX_RX_END,
- TX_RX_SUCCESS,
- TX_RX_ERR,
-};
-
-const int start_magic = 0x5a5aa5a5;
-const int end_magic = 0xa5a55a5a;
-
-#define txrx(fd, buf, size, flags) (recv_send ? \
- recv(fd, buf, size, flags) : \
- send(fd, buf, size, flags))
-
-/* non-blocking send/receive with n second timeout */
-static enum tx_rx_state
-tx_rx_message(int fd, struct md_message *msg, int recv_send, int tmo)
+static const __u32 start_magic = 0x5a5aa5a5;
+static const __u32 end_magic = 0xa5a55a5a;
+
+static int send_buf(int fd, const void* buf, int len, int tmo)
{
- int d = recv_send ? 0 : start_magic;
- int flags = recv_send ? 0 : MSG_NOSIGNAL;
- enum tx_rx_state state = TX_RX_START;
- void *buf = &d;
- size_t size = sizeof(d);
- off_t n = 0;
- int rc;
- int again;
-
- do {
- again = 0;
- rc = txrx(fd, buf + n, size - n, flags);
- if (rc <= 0) { /* error */
- if (rc == -1 && errno == EAGAIN)
- again = 1;
- else
- state = TX_RX_ERR;
- } else if (rc + n == size) /* done */
- switch (state) {
- case TX_RX_START:
- if (recv_send && d != start_magic)
- state = TX_RX_ERR;
- else {
- state = TX_RX_SEQ;
- buf = &msg->seq;
- size = sizeof(msg->seq);
- n = 0;
- }
- break;
- case TX_RX_SEQ:
- state = TX_RX_NUM_BYTES;
- buf = &msg->num_bytes;
- size = sizeof(msg->num_bytes);
- n = 0;
- break;
- case TX_RX_NUM_BYTES:
- if (msg->num_bytes >
- sizeof(union md_message_commands))
- state = TX_RX_ERR;
- else if (recv_send && msg->num_bytes) {
- msg->buf = malloc(msg->num_bytes);
- if (!msg->buf)
- state = TX_RX_ERR;
- else {
- state = TX_RX_BUF;
- buf = msg->buf;
- size = msg->num_bytes;
- n = 0;
- }
- } else if (!recv_send && msg->num_bytes) {
- state = TX_RX_BUF;
- buf = msg->buf;
- size = msg->num_bytes;
- n = 0;
- } else {
- d = recv_send ? 0 : end_magic;
- state = TX_RX_END;
- buf = &d;
- size = sizeof(d);
- n = 0;
- }
- break;
- case TX_RX_BUF:
- d = recv_send ? 0 : end_magic;
- state = TX_RX_END;
- buf = &d;
- size = sizeof(d);
- n = 0;
- break;
- case TX_RX_END:
- if (recv_send && d != end_magic)
- state = TX_RX_ERR;
- else
- state = TX_RX_SUCCESS;
- break;
- case TX_RX_ERR:
- case TX_RX_SUCCESS:
- break;
- }
- else /* continue */
- n += rc;
-
- if (again) {
- fd_set set;
- struct timeval timeout = { tmo, 0 };
- struct timeval *ptmo = tmo ? &timeout : NULL;
-
- FD_ZERO(&set);
- FD_SET(fd, &set);
-
- if (recv_send)
- rc = select(fd + 1, &set, NULL, NULL, ptmo);
- else
- rc = select(fd + 1, NULL, &set, NULL, ptmo);
-
- if (rc <= 0)
- state = TX_RX_ERR;
- }
- } while (state < TX_RX_SUCCESS);
+ fd_set set;
+ int rv;
+ struct timeval timeout = {tmo, 0};
+ struct timeval *ptmo = tmo ? &timeout : NULL;
+
+ while (len) {
+ FD_ZERO(&set);
+ FD_SET(fd, &set);
+ rv = select(fd+1, NULL, &set, NULL, ptmo);
+ if (rv <= 0)
+ return -1;
+ rv = write(fd, buf, len);
+ if (rv <= 0)
+ return -1;
+ len -= rv;
+ buf += rv;
+ }
+ return 0;
+}
- return state;
+static int recv_buf(int fd, void* buf, int len, int tmo)
+{
+ fd_set set;
+ int rv;
+ struct timeval timeout = {tmo, 0};
+ struct timeval *ptmo = tmo ? &timeout : NULL;
+
+ while (len) {
+ FD_ZERO(&set);
+ FD_SET(fd, &set);
+ rv = select(fd+1, &set, NULL, NULL, ptmo);
+ if (rv <= 0)
+ return -1;
+ rv = read(fd, buf, len);
+ if (rv <= 0)
+ return -1;
+ len -= rv;
+ buf += rv;
+ }
+ return 0;
}
-int receive_message(int fd, struct md_message *msg, int tmo)
+int send_message(int fd, struct metadata_update *msg, int tmo)
{
- if (tx_rx_message(fd, msg, 1, tmo) == TX_RX_SUCCESS)
- return 0;
- else
- return -1;
+ __s32 len = msg->len;
+ int rv;
+
+ rv = send_buf(fd, &start_magic, 4, tmo);
+ rv = rv ?: send_buf(fd, &len, 4, tmo);
+ if (len > 0)
+ rv = rv ?: send_buf(fd, msg->buf, msg->len, tmo);
+ rv = send_buf(fd, &end_magic, 4, tmo);
+
+ return rv;
}
-int send_message(int fd, struct md_message *msg, int tmo)
+int receive_message(int fd, struct metadata_update *msg, int tmo)
{
- if (tx_rx_message(fd, msg, 0, tmo) == TX_RX_SUCCESS)
- return 0;
- else
+ __u32 magic;
+ __s32 len;
+ int rv;
+
+ rv = recv_buf(fd, &magic, 4, tmo);
+ if (rv < 0 || magic != start_magic)
return -1;
+ rv = recv_buf(fd, &len, 4, tmo);
+ if (rv < 0 || len > MSG_MAX_LEN)
+ return -1;
+ if (len > 0) {
+ msg->buf = malloc(len);
+ if (msg->buf == NULL)
+ return -1;
+ rv = recv_buf(fd, msg->buf, len, tmo);
+ if (rv < 0) {
+ free(msg->buf);
+ return -1;
+ }
+ } else
+ msg->buf = NULL;
+ rv = recv_buf(fd, &magic, 4, tmo);
+ if (rv < 0 || magic != end_magic) {
+ free(msg->buf);
+ return -1;
+ }
+ msg->len = len;
+ return 0;
}
-int ack(int fd, int seq, int tmo)
+int ack(int fd, int tmo)
{
- struct md_message msg = { .seq = seq, .num_bytes = 0 };
+ struct metadata_update msg = { .len = 0 };
return send_message(fd, &msg, tmo);
}
-int nack(int fd, int err, int tmo)
+int wait_reply(int fd, int tmo)
{
- struct md_message msg = { .seq = err, .num_bytes = 0 };
-
- return send_message(fd, &msg, tmo);
+ struct metadata_update msg;
+ return receive_message(fd, &msg, tmo);
}
int connect_monitor(char *devname)
int sfd;
long fl;
struct sockaddr_un addr;
+ int pos;
+ char *c;
+
+ pos = sprintf(path, "%s/", MDMON_DIR);
+ if (is_subarray(devname)) {
+ devname++;
+ c = strchr(devname, '/');
+ if (!c)
+ return -1;
+ snprintf(&path[pos], c - devname + 1, "%s", devname);
+ pos += c - devname;
+ } else
+ pos += sprintf(&path[pos], "%s", devname);
+ sprintf(&path[pos], ".sock");
- sprintf(path, "/var/run/mdadm/%s.sock", devname);
sfd = socket(PF_LOCAL, SOCK_STREAM, 0);
if (sfd < 0)
return -1;
return sfd;
}
-int ping_monitor(char *devname)
+int fping_monitor(int sfd)
{
- int sfd = connect_monitor(devname);
- struct md_message msg;
int err = 0;
if (sfd < 0)
return sfd;
/* try to ping existing socket */
- if (ack(sfd, 0, 0) != 0)
+ if (ack(sfd, 20) != 0)
err = -1;
/* check the reply */
- if (!err && receive_message(sfd, &msg, 0) != 0)
+ if (!err && wait_reply(sfd, 20) != 0)
err = -1;
- if (msg.seq != 0)
+ return err;
+}
+
+
+/* give the monitor a chance to update the metadata */
+int ping_monitor(char *devname)
+{
+ int sfd = connect_monitor(devname);
+ int err = fping_monitor(sfd);
+
+ close(sfd);
+ return err;
+}
+
+/* give the manager a chance to view the updated container state. This
+ * would naturally happen due to the manager noticing a change in
+ * /proc/mdstat; however, pinging encourages this detection to happen
+ * while an exclusive open() on the container is active
+ */
+int ping_manager(char *devname)
+{
+ int sfd = connect_monitor(devname);
+ struct metadata_update msg = { .len = -1 };
+ int err = 0;
+
+ if (sfd < 0)
+ return sfd;
+
+ err = send_message(sfd, &msg, 20);
+
+ /* check the reply */
+ if (!err && wait_reply(sfd, 20) != 0)
err = -1;
close(sfd);
projects / thirdparty / mdadm.git / blobdiff