From: Paolo Bonzini Date: Tue, 22 Aug 2017 06:50:55 +0200 Subject: [PATCH] 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 --- Makefile | 3 + configure | 54 ++++++++ docs/pr-manager.rst | 27 ++++ include/scsi/utils.h | 4 + scsi/qemu-pr-helper.c | 357 +++++++++++++++++++++++++++++++++++++++++++++++++- scsi/utils.c | 10 ++ 6 files changed, 452 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index f07c0d7e9c..060c089af9 100644 --- a/Makefile +++ b/Makefile @@ -383,6 +383,9 @@ fsdev/virtfs-proxy-helper$(EXESUF): fsdev/virtfs-proxy-helper.o fsdev/9p-marshal fsdev/virtfs-proxy-helper$(EXESUF): LIBS += -lcap scsi/qemu-pr-helper$(EXESUF): scsi/qemu-pr-helper.o scsi/utils.o $(crypto-obj-y) $(io-obj-y) $(qom-obj-y) $(COMMON_LDADDS) +ifdef CONFIG_MPATH +scsi/qemu-pr-helper$(EXESUF): LIBS += -ludev -lmultipath -lmpathpersist +endif qemu-img-cmds.h: $(SRC_PATH)/qemu-img-cmds.hx $(SRC_PATH)/scripts/hxtool $(call quiet-command,sh $(SRC_PATH)/scripts/hxtool -h < $< > $@,"GEN","$@") diff --git a/configure b/configure index 14bdf9bb31..9eeb3ebf70 100755 --- a/configure +++ b/configure @@ -286,6 +286,7 @@ pixman="" sdl="" sdlabi="" virtfs="" +mpath="" vnc="yes" sparse="no" vde="" @@ -948,6 +949,10 @@ for opt do ;; --enable-virtfs) virtfs="yes" ;; + --disable-mpath) mpath="no" + ;; + --enable-mpath) mpath="yes" + ;; --disable-vnc) vnc="no" ;; --enable-vnc) vnc="yes" @@ -1491,6 +1496,7 @@ disabled with --disable-FEATURE, default is enabled if available: vnc-png PNG compression for VNC server cocoa Cocoa UI (Mac OS X only) virtfs VirtFS + mpath Multipath persistent reservation passthrough xen xen backend driver support xen-pci-passthrough brlapi BrlAPI (Braile) @@ -3335,6 +3341,38 @@ else pixman_libs="-L\$(BUILD_DIR)/pixman/pixman/.libs -lpixman-1" fi +########################################## +# libmpathpersist probe + +if test "$mpath" != "no" ; then + cat > $TMPC < +#include +unsigned mpath_mx_alloc_len = 1024; +int logsink; +static struct config *multipath_conf; +extern struct udev *udev; +extern struct config *get_multipath_config(void); +extern void put_multipath_config(struct config *conf); +struct udev *udev; +struct config *get_multipath_config(void) { return multipath_conf; } +void put_multipath_config(struct config *conf) { } + +int main(void) { + udev = udev_new(); + multipath_conf = mpath_lib_init(); + return 0; +} +EOF + if compile_prog "" "-ludev -lmultipath -lmpathpersist" ; then + mpathpersist=yes + else + mpathpersist=no + fi +else + mpathpersist=no +fi + ########################################## # libcap probe @@ -5080,12 +5118,24 @@ if test "$softmmu" = yes ; then fi virtfs=no fi + if test "$mpath" != no && test "$mpathpersist" = yes ; then + mpath=yes + else + if test "$mpath" = yes; then + error_exit "Multipath requires libmpathpersist devel" + fi + mpath=no + fi tools="$tools scsi/qemu-pr-helper\$(EXESUF)" else if test "$virtfs" = yes; then error_exit "VirtFS is supported only on Linux" fi virtfs=no + if test "$mpath" = yes; then + error_exit "Multipath is supported only on Linux" + fi + mpath=no fi fi @@ -5332,6 +5382,7 @@ echo "Audio drivers $audio_drv_list" echo "Block whitelist (rw) $block_drv_rw_whitelist" echo "Block whitelist (ro) $block_drv_ro_whitelist" echo "VirtFS support $virtfs" +echo "Multipath support $mpath" echo "VNC support $vnc" if test "$vnc" = "yes" ; then echo "VNC SASL support $vnc_sasl" @@ -5779,6 +5830,9 @@ fi if test "$virtfs" = "yes" ; then echo "CONFIG_VIRTFS=y" >> $config_host_mak fi +if test "$mpath" = "yes" ; then + echo "CONFIG_MPATH=y" >> $config_host_mak +fi if test "$vhost_scsi" = "yes" ; then echo "CONFIG_VHOST_SCSI=y" >> $config_host_mak fi diff --git a/docs/pr-manager.rst b/docs/pr-manager.rst index 7107e59fb8..9b1de198b1 100644 --- a/docs/pr-manager.rst +++ b/docs/pr-manager.rst @@ -60,6 +60,7 @@ system service and supports the following option: -d, --daemon run in the background -q, --quiet decrease verbosity +-v, --verbose increase verbosity -f, --pidfile=path PID file when running as a daemon -k, --socket=path path to the socket -T, --trace=trace-opts tracing options @@ -82,3 +83,29 @@ its operation. To do this, add the following options: -u, --user=user user to drop privileges to -g, --group=group group to drop privileges to + +--------------------------------------------- +Multipath devices and persistent reservations +--------------------------------------------- + +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 is newly discovered or becomes online +again. :command:`qemu-pr-helper` can do this if the ``libmpathpersist`` +library was available on the system at build time. + +As of August 2017, a reservation key must be specified in ``multipath.conf`` +for ``multipathd`` to check for persistent reservation for newly +discovered paths or reinstated paths. The attribute can be added +to the ``defaults`` section or the ``multipaths`` section; for example:: + + multipaths { + multipath { + wwid XXXXXXXXXXXXXXXX + alias yellow + reservation_key 0x123abc + } + } + +Linking :program:`qemu-pr-helper` to ``libmpathpersist`` does not impede +its usage on regular SCSI devices. diff --git a/include/scsi/utils.h b/include/scsi/utils.h index d301b31768..00a4bdb080 100644 --- a/include/scsi/utils.h +++ b/include/scsi/utils.h @@ -72,10 +72,14 @@ extern const struct SCSISense sense_code_IO_ERROR; extern const struct SCSISense sense_code_I_T_NEXUS_LOSS; /* Command aborted, Logical Unit failure */ extern const struct SCSISense sense_code_LUN_FAILURE; +/* Command aborted, LUN Communication failure */ +extern const struct SCSISense sense_code_LUN_COMM_FAILURE; /* Command aborted, Overlapped Commands Attempted */ extern const struct SCSISense sense_code_OVERLAPPED_COMMANDS; /* LUN not ready, Capacity data has changed */ extern const struct SCSISense sense_code_CAPACITY_CHANGED; +/* Unit attention, SCSI bus reset */ +extern const struct SCSISense sense_code_SCSI_BUS_RESET; /* LUN not ready, Medium not present */ extern const struct SCSISense sense_code_UNIT_ATTENTION_NO_MEDIUM; /* Unit attention, Power on, reset or bus device reset occurred */ diff --git a/scsi/qemu-pr-helper.c b/scsi/qemu-pr-helper.c index e39efbd529..be6d1fbade 100644 --- a/scsi/qemu-pr-helper.c +++ b/scsi/qemu-pr-helper.c @@ -30,6 +30,12 @@ #include #include +#ifdef CONFIG_MPATH +#include +#include +#include +#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 +211,327 @@ 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); +static struct config *multipath_conf; +unsigned mpath_mx_alloc_len = PR_HELPER_DATA_SIZE; +int logsink; +struct udev *udev; + +extern struct config *get_multipath_config(void); +struct config *get_multipath_config(void) +{ + return multipath_conf; +} + +extern void put_multipath_config(struct config *conf); +void put_multipath_config(struct config *conf) +{ +} + +static void multipath_pr_init(void) +{ + udev = udev_new(); + multipath_conf = mpath_lib_init(); +} + +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(¶mp, 0, sizeof(paramp)); + memcpy(¶mp.key, ¶m[0], 8); + memcpy(¶mp.sa_key, ¶m[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(¶m[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, ¶m[i + 8], 8); + j += offsetof(struct transportid, n_port_name[8]); + i += 24; + break; + case 3: + case 0x43: + /* iSCSI transport. */ + len = lduw_be_p(¶m[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(¶m[i + 4], 0, len) == NULL) { + goto illegal_req; + } + memcpy(id->iscsi_name, ¶m[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, ¶m[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, + ¶mp, 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 +539,14 @@ 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 +857,14 @@ 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 +881,7 @@ 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 +891,12 @@ 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; char ch; Error *local_err = NULL; @@ -631,6 +973,9 @@ 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 +995,8 @@ 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 +1004,11 @@ 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 fab60bdf20..5684951b12 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