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authorPaolo Bonzini <pbonzini@redhat.com>2017-08-22 06:50:55 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2017-09-22 21:07:27 +0200
commitfe8fc5ae5c808e037fa4746cbfeb3c07ffe0af81 (patch)
tree973ce75621cb47f79167bde4e48bdc357ed58bde /scsi
parentb855f8d175a0a26c9798cbc5962bb8c0d9538231 (diff)
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scsi: add multipath support to qemu-pr-helper
Proper support of persistent reservation for multipath devices requires communication with the multipath daemon, so that the reservation is registered and applied when a path comes up. The device mapper utilities provide a library to do so; this patch makes qemu-pr-helper.c detect multipath devices and, when one is found, delegate the operation to libmpathpersist. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'scsi')
-rw-r--r--scsi/qemu-pr-helper.c346
-rw-r--r--scsi/utils.c10
2 files changed, 353 insertions, 3 deletions
diff --git a/scsi/qemu-pr-helper.c b/scsi/qemu-pr-helper.c
index f46266f..d581848 100644
--- a/scsi/qemu-pr-helper.c
+++ b/scsi/qemu-pr-helper.c
@@ -30,6 +30,12 @@
#include <pwd.h>
#include <grp.h>
+#ifdef CONFIG_MPATH
+#include <libudev.h>
+#include <mpath_cmd.h>
+#include <mpath_persist.h>
+#endif
+
#include "qapi/error.h"
#include "qemu-common.h"
#include "qemu/cutils.h"
@@ -60,6 +66,7 @@ static enum { RUNNING, TERMINATE, TERMINATING } state;
static QIOChannelSocket *server_ioc;
static int server_watch;
static int num_active_sockets = 1;
+static int noisy;
static int verbose;
#ifdef CONFIG_LIBCAP
@@ -204,9 +211,316 @@ static int do_sgio(int fd, const uint8_t *cdb, uint8_t *sense,
return r;
}
+/* Device mapper interface */
+
+#ifdef CONFIG_MPATH
+#define CONTROL_PATH "/dev/mapper/control"
+
+typedef struct DMData {
+ struct dm_ioctl dm;
+ uint8_t data[1024];
+} DMData;
+
+static int control_fd;
+
+static void *dm_ioctl(int ioc, struct dm_ioctl *dm)
+{
+ static DMData d;
+ memcpy(&d.dm, dm, sizeof(d.dm));
+ QEMU_BUILD_BUG_ON(sizeof(d.data) < sizeof(struct dm_target_spec));
+
+ d.dm.version[0] = DM_VERSION_MAJOR;
+ d.dm.version[1] = 0;
+ d.dm.version[2] = 0;
+ d.dm.data_size = 1024;
+ d.dm.data_start = offsetof(DMData, data);
+ if (ioctl(control_fd, ioc, &d) < 0) {
+ return NULL;
+ }
+ memcpy(dm, &d.dm, sizeof(d.dm));
+ return &d.data;
+}
+
+static void *dm_dev_ioctl(int fd, int ioc, struct dm_ioctl *dm)
+{
+ struct stat st;
+ int r;
+
+ r = fstat(fd, &st);
+ if (r < 0) {
+ perror("fstat");
+ exit(1);
+ }
+
+ dm->dev = st.st_rdev;
+ return dm_ioctl(ioc, dm);
+}
+
+static void dm_init(void)
+{
+ control_fd = open(CONTROL_PATH, O_RDWR);
+ if (control_fd < 0) {
+ perror("Cannot open " CONTROL_PATH);
+ exit(1);
+ }
+ struct dm_ioctl dm = { 0 };
+ if (!dm_ioctl(DM_VERSION, &dm)) {
+ perror("ioctl");
+ exit(1);
+ }
+ if (dm.version[0] != DM_VERSION_MAJOR) {
+ fprintf(stderr, "Unsupported device mapper interface");
+ exit(1);
+ }
+}
+
+/* Variables required by libmultipath and libmpathpersist. */
+QEMU_BUILD_BUG_ON(PR_HELPER_DATA_SIZE > MPATH_MAX_PARAM_LEN);
+unsigned mpath_mx_alloc_len = PR_HELPER_DATA_SIZE;
+int logsink;
+
+static void multipath_pr_init(void)
+{
+ static struct udev *udev;
+
+ udev = udev_new();
+ mpath_lib_init(udev);
+}
+
+static int is_mpath(int fd)
+{
+ struct dm_ioctl dm = { .flags = DM_NOFLUSH_FLAG };
+ struct dm_target_spec *tgt;
+
+ tgt = dm_dev_ioctl(fd, DM_TABLE_STATUS, &dm);
+ if (!tgt) {
+ if (errno == ENXIO) {
+ return 0;
+ }
+ perror("ioctl");
+ exit(EXIT_FAILURE);
+ }
+ return !strncmp(tgt->target_type, "multipath", DM_MAX_TYPE_NAME);
+}
+
+static int mpath_reconstruct_sense(int fd, int r, uint8_t *sense)
+{
+ switch (r) {
+ case MPATH_PR_SUCCESS:
+ return GOOD;
+ case MPATH_PR_SENSE_NOT_READY:
+ case MPATH_PR_SENSE_MEDIUM_ERROR:
+ case MPATH_PR_SENSE_HARDWARE_ERROR:
+ case MPATH_PR_SENSE_ABORTED_COMMAND:
+ {
+ /* libmpathpersist ate the exact sense. Try to find it by
+ * issuing TEST UNIT READY.
+ */
+ uint8_t cdb[6] = { TEST_UNIT_READY };
+ int sz = 0;
+ return do_sgio(fd, cdb, sense, NULL, &sz, SG_DXFER_NONE);
+ }
+
+ case MPATH_PR_SENSE_UNIT_ATTENTION:
+ /* Congratulations libmpathpersist, you ruined the Unit Attention...
+ * Return a heavyweight one.
+ */
+ scsi_build_sense(sense, SENSE_CODE(SCSI_BUS_RESET));
+ return CHECK_CONDITION;
+ case MPATH_PR_SENSE_INVALID_OP:
+ /* Only one valid sense. */
+ scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE));
+ return CHECK_CONDITION;
+ case MPATH_PR_ILLEGAL_REQ:
+ /* Guess. */
+ scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM));
+ return CHECK_CONDITION;
+ case MPATH_PR_NO_SENSE:
+ scsi_build_sense(sense, SENSE_CODE(NO_SENSE));
+ return CHECK_CONDITION;
+
+ case MPATH_PR_RESERV_CONFLICT:
+ return RESERVATION_CONFLICT;
+
+ case MPATH_PR_OTHER:
+ default:
+ scsi_build_sense(sense, SENSE_CODE(LUN_COMM_FAILURE));
+ return CHECK_CONDITION;
+ }
+}
+
+static int multipath_pr_in(int fd, const uint8_t *cdb, uint8_t *sense,
+ uint8_t *data, int sz)
+{
+ int rq_servact = cdb[1];
+ struct prin_resp resp;
+ size_t written;
+ int r;
+
+ switch (rq_servact) {
+ case MPATH_PRIN_RKEY_SA:
+ case MPATH_PRIN_RRES_SA:
+ case MPATH_PRIN_RCAP_SA:
+ break;
+ case MPATH_PRIN_RFSTAT_SA:
+ /* Nobody implements it anyway, so bail out. */
+ default:
+ /* Cannot parse any other output. */
+ scsi_build_sense(sense, SENSE_CODE(INVALID_FIELD));
+ return CHECK_CONDITION;
+ }
+
+ r = mpath_persistent_reserve_in(fd, rq_servact, &resp, noisy, verbose);
+ if (r == MPATH_PR_SUCCESS) {
+ switch (rq_servact) {
+ case MPATH_PRIN_RKEY_SA:
+ case MPATH_PRIN_RRES_SA: {
+ struct prin_readdescr *out = &resp.prin_descriptor.prin_readkeys;
+ assert(sz >= 8);
+ written = MIN(out->additional_length + 8, sz);
+ stl_be_p(&data[0], out->prgeneration);
+ stl_be_p(&data[4], out->additional_length);
+ memcpy(&data[8], out->key_list, written - 8);
+ break;
+ }
+ case MPATH_PRIN_RCAP_SA: {
+ struct prin_capdescr *out = &resp.prin_descriptor.prin_readcap;
+ assert(sz >= 6);
+ written = 6;
+ stw_be_p(&data[0], out->length);
+ data[2] = out->flags[0];
+ data[3] = out->flags[1];
+ stw_be_p(&data[4], out->pr_type_mask);
+ break;
+ }
+ default:
+ scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE));
+ return CHECK_CONDITION;
+ }
+ assert(written <= sz);
+ memset(data + written, 0, sz - written);
+ }
+
+ return mpath_reconstruct_sense(fd, r, sense);
+}
+
+static int multipath_pr_out(int fd, const uint8_t *cdb, uint8_t *sense,
+ const uint8_t *param, int sz)
+{
+ int rq_servact = cdb[1];
+ int rq_scope = cdb[2] >> 4;
+ int rq_type = cdb[2] & 0xf;
+ struct prout_param_descriptor paramp;
+ char transportids[PR_HELPER_DATA_SIZE];
+ int r;
+
+ switch (rq_servact) {
+ case MPATH_PROUT_REG_SA:
+ case MPATH_PROUT_RES_SA:
+ case MPATH_PROUT_REL_SA:
+ case MPATH_PROUT_CLEAR_SA:
+ case MPATH_PROUT_PREE_SA:
+ case MPATH_PROUT_PREE_AB_SA:
+ case MPATH_PROUT_REG_IGN_SA:
+ break;
+ case MPATH_PROUT_REG_MOV_SA:
+ /* Not supported by struct prout_param_descriptor. */
+ default:
+ /* Cannot parse any other input. */
+ scsi_build_sense(sense, SENSE_CODE(INVALID_FIELD));
+ return CHECK_CONDITION;
+ }
+
+ /* Convert input data, especially transport IDs, to the structs
+ * used by libmpathpersist (which, of course, will immediately
+ * do the opposite).
+ */
+ memset(&paramp, 0, sizeof(paramp));
+ memcpy(&paramp.key, &param[0], 8);
+ memcpy(&paramp.sa_key, &param[8], 8);
+ paramp.sa_flags = param[10];
+ if (sz > PR_OUT_FIXED_PARAM_SIZE) {
+ size_t transportid_len;
+ int i, j;
+ if (sz < PR_OUT_FIXED_PARAM_SIZE + 4) {
+ scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM_LEN));
+ return CHECK_CONDITION;
+ }
+ transportid_len = ldl_be_p(&param[24]) + PR_OUT_FIXED_PARAM_SIZE + 4;
+ if (transportid_len > sz) {
+ scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM));
+ return CHECK_CONDITION;
+ }
+ for (i = PR_OUT_FIXED_PARAM_SIZE + 4, j = 0; i < transportid_len; ) {
+ struct transportid *id = (struct transportid *) &transportids[j];
+ int len;
+
+ id->format_code = param[i] & 0xc0;
+ id->protocol_id = param[i] & 0x0f;
+ switch (param[i] & 0xcf) {
+ case 0:
+ /* FC transport. */
+ if (i + 24 > transportid_len) {
+ goto illegal_req;
+ }
+ memcpy(id->n_port_name, &param[i + 8], 8);
+ j += offsetof(struct transportid, n_port_name[8]);
+ i += 24;
+ break;
+ case 3:
+ case 0x43:
+ /* iSCSI transport. */
+ len = lduw_be_p(&param[i + 2]);
+ if (len > 252 || (len & 3) || i + len + 4 > transportid_len) {
+ /* For format code 00, the standard says the maximum is 223
+ * plus the NUL terminator. For format code 01 there is no
+ * maximum length, but libmpathpersist ignores the first
+ * byte of id->iscsi_name so our maximum is 252.
+ */
+ goto illegal_req;
+ }
+ if (memchr(&param[i + 4], 0, len) == NULL) {
+ goto illegal_req;
+ }
+ memcpy(id->iscsi_name, &param[i + 2], len + 2);
+ j += offsetof(struct transportid, iscsi_name[len + 2]);
+ i += len + 4;
+ break;
+ case 6:
+ /* SAS transport. */
+ if (i + 24 > transportid_len) {
+ goto illegal_req;
+ }
+ memcpy(id->sas_address, &param[i + 4], 8);
+ j += offsetof(struct transportid, sas_address[8]);
+ i += 24;
+ break;
+ default:
+ illegal_req:
+ scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM));
+ return CHECK_CONDITION;
+ }
+
+ paramp.trnptid_list[paramp.num_transportid++] = id;
+ }
+ }
+
+ r = mpath_persistent_reserve_out(fd, rq_servact, rq_scope, rq_type,
+ &paramp, noisy, verbose);
+ return mpath_reconstruct_sense(fd, r, sense);
+}
+#endif
+
static int do_pr_in(int fd, const uint8_t *cdb, uint8_t *sense,
uint8_t *data, int *resp_sz)
{
+#ifdef CONFIG_MPATH
+ if (is_mpath(fd)) {
+ /* multipath_pr_in fills the whole input buffer. */
+ return multipath_pr_in(fd, cdb, sense, data, *resp_sz);
+ }
+#endif
+
return do_sgio(fd, cdb, sense, data, resp_sz,
SG_DXFER_FROM_DEV);
}
@@ -214,7 +528,14 @@ static int do_pr_in(int fd, const uint8_t *cdb, uint8_t *sense,
static int do_pr_out(int fd, const uint8_t *cdb, uint8_t *sense,
const uint8_t *param, int sz)
{
- int resp_sz = sz;
+ int resp_sz;
+#ifdef CONFIG_MPATH
+ if (is_mpath(fd)) {
+ return multipath_pr_out(fd, cdb, sense, param, sz);
+ }
+#endif
+
+ resp_sz = sz;
return do_sgio(fd, cdb, sense, (uint8_t *)param, &resp_sz,
SG_DXFER_TO_DEV);
}
@@ -525,6 +846,14 @@ static int drop_privileges(void)
return -1;
}
+#ifdef CONFIG_MPATH
+ /* For /dev/mapper/control ioctls */
+ if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED,
+ CAP_SYS_ADMIN) < 0) {
+ return -1;
+ }
+#endif
+
/* Change user/group id, retaining the capabilities. Because file descriptors
* are passed via SCM_RIGHTS, we don't need supplementary groups (and in
* fact the helper can run as "nobody").
@@ -541,7 +870,7 @@ static int drop_privileges(void)
int main(int argc, char **argv)
{
- const char *sopt = "hVk:fdT:u:g:q";
+ const char *sopt = "hVk:fdT:u:g:vq";
struct option lopt[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
@@ -551,10 +880,12 @@ int main(int argc, char **argv)
{ "trace", required_argument, NULL, 'T' },
{ "user", required_argument, NULL, 'u' },
{ "group", required_argument, NULL, 'g' },
+ { "verbose", no_argument, NULL, 'v' },
{ "quiet", no_argument, NULL, 'q' },
{ NULL, 0, NULL, 0 }
};
int opt_ind = 0;
+ int loglevel = 1;
int quiet = 0;
int ch;
Error *local_err = NULL;
@@ -631,6 +962,9 @@ int main(int argc, char **argv)
case 'q':
quiet = 1;
break;
+ case 'v':
+ ++loglevel;
+ break;
case 'T':
g_free(trace_file);
trace_file = trace_opt_parse(optarg);
@@ -650,7 +984,8 @@ int main(int argc, char **argv)
}
/* set verbosity */
- verbose = !quiet;
+ noisy = !quiet && (loglevel >= 3);
+ verbose = quiet ? 0 : MIN(loglevel, 3);
if (!trace_init_backends()) {
exit(EXIT_FAILURE);
@@ -658,6 +993,11 @@ int main(int argc, char **argv)
trace_init_file(trace_file);
qemu_set_log(LOG_TRACE);
+#ifdef CONFIG_MPATH
+ dm_init();
+ multipath_pr_init();
+#endif
+
socket_activation = check_socket_activation();
if (socket_activation == 0) {
SocketAddress saddr;
diff --git a/scsi/utils.c b/scsi/utils.c
index fab60bd..5684951 100644
--- a/scsi/utils.c
+++ b/scsi/utils.c
@@ -206,6 +206,11 @@ const struct SCSISense sense_code_OVERLAPPED_COMMANDS = {
.key = ABORTED_COMMAND, .asc = 0x4e, .ascq = 0x00
};
+/* Command aborted, LUN Communication Failure */
+const struct SCSISense sense_code_LUN_COMM_FAILURE = {
+ .key = ABORTED_COMMAND, .asc = 0x08, .ascq = 0x00
+};
+
/* Unit attention, Capacity data has changed */
const struct SCSISense sense_code_CAPACITY_CHANGED = {
.key = UNIT_ATTENTION, .asc = 0x2a, .ascq = 0x09
@@ -216,6 +221,11 @@ const struct SCSISense sense_code_RESET = {
.key = UNIT_ATTENTION, .asc = 0x29, .ascq = 0x00
};
+/* Unit attention, SCSI bus reset */
+const struct SCSISense sense_code_SCSI_BUS_RESET = {
+ .key = UNIT_ATTENTION, .asc = 0x29, .ascq = 0x02
+};
+
/* Unit attention, No medium */
const struct SCSISense sense_code_UNIT_ATTENTION_NO_MEDIUM = {
.key = UNIT_ATTENTION, .asc = 0x3a, .ascq = 0x00