| 1 | /* |
| 2 | * Copyright (c) 2012-2014 The DragonFly Project. All rights reserved. |
| 3 | * |
| 4 | * This code is derived from software contributed to The DragonFly Project |
| 5 | * by Matthew Dillon <dillon@dragonflybsd.org> |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in |
| 15 | * the documentation and/or other materials provided with the |
| 16 | * distribution. |
| 17 | * 3. Neither the name of The DragonFly Project nor the names of its |
| 18 | * contributors may be used to endorse or promote products derived |
| 19 | * from this software without specific, prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 22 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 23 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 24 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 25 | * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 26 | * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 27 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 28 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| 29 | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 30 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 31 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 32 | * SUCH DAMAGE. |
| 33 | */ |
| 34 | /* |
| 35 | * This module allows disk devices to be created and associated with a |
| 36 | * communications pipe or socket. You open the device and issue an |
| 37 | * ioctl() to install a new disk along with its communications descriptor. |
| 38 | * |
| 39 | * All further communication occurs via the descriptor using the DMSG |
| 40 | * LNK_CONN, LNK_SPAN, and BLOCK protocols. The descriptor can be a |
| 41 | * direct connection to a remote machine's disk (in-kernenl), to a remote |
| 42 | * cluster controller, to the local cluster controller, etc. |
| 43 | * |
| 44 | * /dev/xdisk is the control device, issue ioctl()s to create the /dev/xa%d |
| 45 | * devices. These devices look like raw disks to the system. |
| 46 | */ |
| 47 | #include <sys/param.h> |
| 48 | #include <sys/systm.h> |
| 49 | #include <sys/buf.h> |
| 50 | #include <sys/conf.h> |
| 51 | #include <sys/device.h> |
| 52 | #include <sys/devicestat.h> |
| 53 | #include <sys/disk.h> |
| 54 | #include <sys/kernel.h> |
| 55 | #include <sys/malloc.h> |
| 56 | #include <sys/sysctl.h> |
| 57 | #include <sys/proc.h> |
| 58 | #include <sys/queue.h> |
| 59 | #include <sys/tree.h> |
| 60 | #include <sys/udev.h> |
| 61 | #include <sys/uuid.h> |
| 62 | #include <sys/kern_syscall.h> |
| 63 | |
| 64 | #include <sys/dmsg.h> |
| 65 | #include <sys/xdiskioctl.h> |
| 66 | |
| 67 | #include <sys/buf2.h> |
| 68 | #include <sys/thread2.h> |
| 69 | |
| 70 | struct xa_softc; |
| 71 | struct xa_softc_tree; |
| 72 | RB_HEAD(xa_softc_tree, xa_softc); |
| 73 | RB_PROTOTYPE(xa_softc_tree, xa_softc, rbnode, xa_softc_cmp); |
| 74 | |
| 75 | static int xa_active; |
| 76 | SYSCTL_INT(_debug, OID_AUTO, xa_active, CTLFLAG_RW, &xa_active, 0, |
| 77 | "Number of active xdisk IOs"); |
| 78 | static uint64_t xa_last; |
| 79 | SYSCTL_ULONG(_debug, OID_AUTO, xa_last, CTLFLAG_RW, &xa_last, 0, |
| 80 | "Offset of last xdisk IO"); |
| 81 | |
| 82 | /* |
| 83 | * Track a BIO tag |
| 84 | */ |
| 85 | struct xa_tag { |
| 86 | TAILQ_ENTRY(xa_tag) entry; |
| 87 | struct xa_softc *sc; |
| 88 | dmsg_blk_error_t status; |
| 89 | kdmsg_state_t *state; |
| 90 | struct bio *bio; |
| 91 | int waiting; |
| 92 | int async; |
| 93 | int done; |
| 94 | }; |
| 95 | |
| 96 | typedef struct xa_tag xa_tag_t; |
| 97 | |
| 98 | /* |
| 99 | * Track devices. |
| 100 | */ |
| 101 | struct xa_softc { |
| 102 | struct kdmsg_state_list spanq; |
| 103 | RB_ENTRY(xa_softc) rbnode; |
| 104 | cdev_t dev; |
| 105 | struct devstat stats; |
| 106 | struct disk_info info; |
| 107 | struct disk disk; |
| 108 | uuid_t pfs_fsid; |
| 109 | int unit; |
| 110 | int opencnt; |
| 111 | int spancnt; |
| 112 | uint64_t keyid; |
| 113 | int serializing; |
| 114 | int last_error; |
| 115 | char cl_label[64]; /* from LNK_SPAN cl_label (host/dev) */ |
| 116 | char fs_label[64]; /* from LNK_SPAN fs_label (serno str) */ |
| 117 | xa_tag_t *open_tag; |
| 118 | TAILQ_HEAD(, bio) bioq; /* pending BIOs */ |
| 119 | TAILQ_HEAD(, xa_tag) tag_freeq; /* available I/O tags */ |
| 120 | TAILQ_HEAD(, xa_tag) tag_pendq; /* running I/O tags */ |
| 121 | struct lock lk; |
| 122 | }; |
| 123 | |
| 124 | typedef struct xa_softc xa_softc_t; |
| 125 | |
| 126 | struct xa_iocom { |
| 127 | TAILQ_ENTRY(xa_iocom) entry; |
| 128 | kdmsg_iocom_t iocom; |
| 129 | xa_softc_t dummysc; |
| 130 | }; |
| 131 | |
| 132 | typedef struct xa_iocom xa_iocom_t; |
| 133 | |
| 134 | static int xa_softc_cmp(xa_softc_t *sc1, xa_softc_t *sc2); |
| 135 | RB_GENERATE(xa_softc_tree, xa_softc, rbnode, xa_softc_cmp); |
| 136 | static struct xa_softc_tree xa_device_tree; |
| 137 | |
| 138 | #define MAXTAGS 64 /* no real limit */ |
| 139 | |
| 140 | static int xdisk_attach(struct xdisk_attach_ioctl *xaioc); |
| 141 | static int xdisk_detach(struct xdisk_attach_ioctl *xaioc); |
| 142 | static void xaio_exit(kdmsg_iocom_t *iocom); |
| 143 | static int xaio_rcvdmsg(kdmsg_msg_t *msg); |
| 144 | |
| 145 | static void xa_terminate_check(struct xa_softc *sc); |
| 146 | |
| 147 | static xa_tag_t *xa_setup_cmd(xa_softc_t *sc, struct bio *bio); |
| 148 | static void xa_start(xa_tag_t *tag, kdmsg_msg_t *msg, int async); |
| 149 | static void xa_done(xa_tag_t *tag, int wasbio); |
| 150 | static void xa_release(xa_tag_t *tag, int wasbio); |
| 151 | static uint32_t xa_wait(xa_tag_t *tag); |
| 152 | static int xa_sync_completion(kdmsg_state_t *state, kdmsg_msg_t *msg); |
| 153 | static int xa_bio_completion(kdmsg_state_t *state, kdmsg_msg_t *msg); |
| 154 | static void xa_restart_deferred(xa_softc_t *sc); |
| 155 | |
| 156 | MALLOC_DEFINE(M_XDISK, "Networked disk client", "Network Disks"); |
| 157 | |
| 158 | /* |
| 159 | * Control device, issue ioctls to create xa devices. |
| 160 | */ |
| 161 | static d_open_t xdisk_open; |
| 162 | static d_close_t xdisk_close; |
| 163 | static d_ioctl_t xdisk_ioctl; |
| 164 | |
| 165 | static struct dev_ops xdisk_ops = { |
| 166 | { "xdisk", 0, D_MPSAFE | D_TRACKCLOSE }, |
| 167 | .d_open = xdisk_open, |
| 168 | .d_close = xdisk_close, |
| 169 | .d_ioctl = xdisk_ioctl |
| 170 | }; |
| 171 | |
| 172 | /* |
| 173 | * XA disk devices |
| 174 | */ |
| 175 | static d_open_t xa_open; |
| 176 | static d_close_t xa_close; |
| 177 | static d_ioctl_t xa_ioctl; |
| 178 | static d_strategy_t xa_strategy; |
| 179 | static d_psize_t xa_size; |
| 180 | |
| 181 | static struct dev_ops xa_ops = { |
| 182 | { "xa", 0, D_DISK | D_CANFREE | D_MPSAFE | D_TRACKCLOSE }, |
| 183 | .d_open = xa_open, |
| 184 | .d_close = xa_close, |
| 185 | .d_ioctl = xa_ioctl, |
| 186 | .d_read = physread, |
| 187 | .d_write = physwrite, |
| 188 | .d_strategy = xa_strategy, |
| 189 | .d_psize = xa_size |
| 190 | }; |
| 191 | |
| 192 | static int xdisk_opencount; |
| 193 | static cdev_t xdisk_dev; |
| 194 | struct lock xdisk_lk; |
| 195 | static TAILQ_HEAD(, xa_iocom) xaiocomq; |
| 196 | |
| 197 | /* |
| 198 | * Module initialization |
| 199 | */ |
| 200 | static int |
| 201 | xdisk_modevent(module_t mod, int type, void *data) |
| 202 | { |
| 203 | switch (type) { |
| 204 | case MOD_LOAD: |
| 205 | TAILQ_INIT(&xaiocomq); |
| 206 | RB_INIT(&xa_device_tree); |
| 207 | lockinit(&xdisk_lk, "xdisk", 0, 0); |
| 208 | xdisk_dev = make_dev(&xdisk_ops, 0, |
| 209 | UID_ROOT, GID_WHEEL, 0600, "xdisk"); |
| 210 | break; |
| 211 | case MOD_UNLOAD: |
| 212 | case MOD_SHUTDOWN: |
| 213 | if (xdisk_opencount || TAILQ_FIRST(&xaiocomq)) |
| 214 | return (EBUSY); |
| 215 | if (xdisk_dev) { |
| 216 | destroy_dev(xdisk_dev); |
| 217 | xdisk_dev = NULL; |
| 218 | } |
| 219 | dev_ops_remove_all(&xdisk_ops); |
| 220 | dev_ops_remove_all(&xa_ops); |
| 221 | break; |
| 222 | default: |
| 223 | break; |
| 224 | } |
| 225 | return 0; |
| 226 | } |
| 227 | |
| 228 | DEV_MODULE(xdisk, xdisk_modevent, 0); |
| 229 | |
| 230 | static int |
| 231 | xa_softc_cmp(xa_softc_t *sc1, xa_softc_t *sc2) |
| 232 | { |
| 233 | return(strcmp(sc1->fs_label, sc2->fs_label)); |
| 234 | } |
| 235 | |
| 236 | /* |
| 237 | * Control device |
| 238 | */ |
| 239 | static int |
| 240 | xdisk_open(struct dev_open_args *ap) |
| 241 | { |
| 242 | lockmgr(&xdisk_lk, LK_EXCLUSIVE); |
| 243 | ++xdisk_opencount; |
| 244 | lockmgr(&xdisk_lk, LK_RELEASE); |
| 245 | return(0); |
| 246 | } |
| 247 | |
| 248 | static int |
| 249 | xdisk_close(struct dev_close_args *ap) |
| 250 | { |
| 251 | lockmgr(&xdisk_lk, LK_EXCLUSIVE); |
| 252 | --xdisk_opencount; |
| 253 | lockmgr(&xdisk_lk, LK_RELEASE); |
| 254 | return(0); |
| 255 | } |
| 256 | |
| 257 | static int |
| 258 | xdisk_ioctl(struct dev_ioctl_args *ap) |
| 259 | { |
| 260 | int error; |
| 261 | |
| 262 | switch(ap->a_cmd) { |
| 263 | case XDISKIOCATTACH: |
| 264 | error = xdisk_attach((void *)ap->a_data); |
| 265 | break; |
| 266 | case XDISKIOCDETACH: |
| 267 | error = xdisk_detach((void *)ap->a_data); |
| 268 | break; |
| 269 | default: |
| 270 | error = ENOTTY; |
| 271 | break; |
| 272 | } |
| 273 | return error; |
| 274 | } |
| 275 | |
| 276 | /************************************************************************ |
| 277 | * DMSG INTERFACE * |
| 278 | ************************************************************************/ |
| 279 | |
| 280 | static int |
| 281 | xdisk_attach(struct xdisk_attach_ioctl *xaioc) |
| 282 | { |
| 283 | xa_iocom_t *xaio; |
| 284 | struct file *fp; |
| 285 | |
| 286 | /* |
| 287 | * Normalize ioctl params |
| 288 | */ |
| 289 | fp = holdfp(curproc->p_fd, xaioc->fd, -1); |
| 290 | if (fp == NULL) |
| 291 | return EINVAL; |
| 292 | kprintf("xdisk_attach fp=%p\n", fp); |
| 293 | |
| 294 | /* |
| 295 | * See if the serial number is already present. If we are |
| 296 | * racing a termination the disk subsystem may still have |
| 297 | * duplicate entries not yet removed so we wait a bit and |
| 298 | * retry. |
| 299 | */ |
| 300 | lockmgr(&xdisk_lk, LK_EXCLUSIVE); |
| 301 | |
| 302 | xaio = kmalloc(sizeof(*xaio), M_XDISK, M_WAITOK | M_ZERO); |
| 303 | kdmsg_iocom_init(&xaio->iocom, xaio, |
| 304 | KDMSG_IOCOMF_AUTOCONN, |
| 305 | M_XDISK, xaio_rcvdmsg); |
| 306 | xaio->iocom.exit_func = xaio_exit; |
| 307 | |
| 308 | kdmsg_iocom_reconnect(&xaio->iocom, fp, "xdisk"); |
| 309 | |
| 310 | /* |
| 311 | * Setup our LNK_CONN advertisement for autoinitiate. |
| 312 | * |
| 313 | * Our filter is setup to only accept PEER_BLOCK/SERVER |
| 314 | * advertisements. |
| 315 | * |
| 316 | * We need a unique pfs_fsid to avoid confusion. |
| 317 | */ |
| 318 | xaio->iocom.auto_lnk_conn.pfs_type = DMSG_PFSTYPE_CLIENT; |
| 319 | xaio->iocom.auto_lnk_conn.proto_version = DMSG_SPAN_PROTO_1; |
| 320 | xaio->iocom.auto_lnk_conn.peer_type = DMSG_PEER_BLOCK; |
| 321 | xaio->iocom.auto_lnk_conn.peer_mask = 1LLU << DMSG_PEER_BLOCK; |
| 322 | xaio->iocom.auto_lnk_conn.pfs_mask = 1LLU << DMSG_PFSTYPE_SERVER; |
| 323 | ksnprintf(xaio->iocom.auto_lnk_conn.fs_label, |
| 324 | sizeof(xaio->iocom.auto_lnk_conn.fs_label), |
| 325 | "xdisk"); |
| 326 | kern_uuidgen(&xaio->iocom.auto_lnk_conn.pfs_fsid, 1); |
| 327 | |
| 328 | /* |
| 329 | * Setup our LNK_SPAN advertisement for autoinitiate |
| 330 | */ |
| 331 | TAILQ_INSERT_TAIL(&xaiocomq, xaio, entry); |
| 332 | kdmsg_iocom_autoinitiate(&xaio->iocom, NULL); |
| 333 | |
| 334 | lockmgr(&xdisk_lk, LK_RELEASE); |
| 335 | |
| 336 | return 0; |
| 337 | } |
| 338 | |
| 339 | static int |
| 340 | xdisk_detach(struct xdisk_attach_ioctl *xaioc) |
| 341 | { |
| 342 | return EINVAL; |
| 343 | } |
| 344 | |
| 345 | /* |
| 346 | * Called from iocom core transmit thread upon disconnect. |
| 347 | */ |
| 348 | static |
| 349 | void |
| 350 | xaio_exit(kdmsg_iocom_t *iocom) |
| 351 | { |
| 352 | xa_iocom_t *xaio = iocom->handle; |
| 353 | |
| 354 | lockmgr(&xdisk_lk, LK_EXCLUSIVE); |
| 355 | kprintf("xdisk_detach [xaio_exit()]\n"); |
| 356 | TAILQ_REMOVE(&xaiocomq, xaio, entry); |
| 357 | lockmgr(&xdisk_lk, LK_RELEASE); |
| 358 | |
| 359 | kdmsg_iocom_uninit(&xaio->iocom); |
| 360 | |
| 361 | kfree(xaio, M_XDISK); |
| 362 | } |
| 363 | |
| 364 | /* |
| 365 | * Called from iocom core to handle messages that the iocom core does not |
| 366 | * handle itself and for which a state function callback has not yet been |
| 367 | * established. |
| 368 | * |
| 369 | * We primarily care about LNK_SPAN transactions here. |
| 370 | */ |
| 371 | static int |
| 372 | xaio_rcvdmsg(kdmsg_msg_t *msg) |
| 373 | { |
| 374 | kdmsg_state_t *state = msg->state; |
| 375 | xa_iocom_t *xaio = state->iocom->handle; |
| 376 | xa_softc_t *sc; |
| 377 | |
| 378 | if (state) { |
| 379 | kprintf("xdisk - rcvmsg state=%p rx=%08x tx=%08x msgcmd=%08x\n", |
| 380 | state, state->rxcmd, state->txcmd, |
| 381 | msg->any.head.cmd); |
| 382 | } |
| 383 | lockmgr(&xdisk_lk, LK_EXCLUSIVE); |
| 384 | |
| 385 | switch(msg->tcmd) { |
| 386 | case DMSG_LNK_SPAN | DMSGF_CREATE | DMSGF_DELETE: |
| 387 | /* |
| 388 | * A LNK_SPAN transaction which is opened and closed |
| 389 | * degenerately is not useful to us, just ignore it. |
| 390 | */ |
| 391 | kdmsg_msg_reply(msg, 0); |
| 392 | break; |
| 393 | case DMSG_LNK_SPAN | DMSGF_CREATE: |
| 394 | /* |
| 395 | * Manage the tracking node for the remote LNK_SPAN. |
| 396 | * |
| 397 | * Return a streaming result, leaving the transaction open |
| 398 | * in both directions to allow sub-transactions. |
| 399 | */ |
| 400 | bcopy(msg->any.lnk_span.cl_label, xaio->dummysc.cl_label, |
| 401 | sizeof(xaio->dummysc.cl_label)); |
| 402 | xaio->dummysc.cl_label[sizeof(xaio->dummysc.cl_label) - 1] = 0; |
| 403 | |
| 404 | bcopy(msg->any.lnk_span.fs_label, xaio->dummysc.fs_label, |
| 405 | sizeof(xaio->dummysc.fs_label)); |
| 406 | xaio->dummysc.fs_label[sizeof(xaio->dummysc.fs_label) - 1] = 0; |
| 407 | |
| 408 | kprintf("xdisk: LINK_SPAN state %p create for %s\n", |
| 409 | msg->state, msg->any.lnk_span.fs_label); |
| 410 | |
| 411 | sc = RB_FIND(xa_softc_tree, &xa_device_tree, &xaio->dummysc); |
| 412 | if (sc == NULL) { |
| 413 | xa_softc_t *sctmp; |
| 414 | xa_tag_t *tag; |
| 415 | cdev_t dev; |
| 416 | int unit; |
| 417 | int n; |
| 418 | |
| 419 | sc = kmalloc(sizeof(*sc), M_XDISK, M_WAITOK | M_ZERO); |
| 420 | bcopy(msg->any.lnk_span.cl_label, sc->cl_label, |
| 421 | sizeof(sc->cl_label)); |
| 422 | sc->cl_label[sizeof(sc->cl_label) - 1] = 0; |
| 423 | bcopy(msg->any.lnk_span.fs_label, sc->fs_label, |
| 424 | sizeof(sc->fs_label)); |
| 425 | sc->fs_label[sizeof(sc->fs_label) - 1] = 0; |
| 426 | |
| 427 | /* XXX FIXME O(N^2) */ |
| 428 | unit = -1; |
| 429 | do { |
| 430 | ++unit; |
| 431 | RB_FOREACH(sctmp, xa_softc_tree, |
| 432 | &xa_device_tree) { |
| 433 | if (sctmp->unit == unit) |
| 434 | break; |
| 435 | } |
| 436 | } while (sctmp); |
| 437 | |
| 438 | sc->unit = unit; |
| 439 | sc->serializing = 1; |
| 440 | sc->spancnt = 1; |
| 441 | lockinit(&sc->lk, "xalk", 0, 0); |
| 442 | TAILQ_INIT(&sc->spanq); |
| 443 | TAILQ_INIT(&sc->bioq); |
| 444 | TAILQ_INIT(&sc->tag_freeq); |
| 445 | TAILQ_INIT(&sc->tag_pendq); |
| 446 | |
| 447 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 448 | RB_INSERT(xa_softc_tree, &xa_device_tree, sc); |
| 449 | TAILQ_INSERT_TAIL(&sc->spanq, msg->state, user_entry); |
| 450 | msg->state->any.xa_sc = sc; |
| 451 | |
| 452 | /* |
| 453 | * Setup block device |
| 454 | */ |
| 455 | for (n = 0; n < MAXTAGS; ++n) { |
| 456 | tag = kmalloc(sizeof(*tag), |
| 457 | M_XDISK, M_WAITOK|M_ZERO); |
| 458 | tag->sc = sc; |
| 459 | TAILQ_INSERT_TAIL(&sc->tag_freeq, tag, entry); |
| 460 | } |
| 461 | |
| 462 | if (sc->dev == NULL) { |
| 463 | dev = disk_create(unit, &sc->disk, &xa_ops); |
| 464 | dev->si_drv1 = sc; |
| 465 | sc->dev = dev; |
| 466 | devstat_add_entry(&sc->stats, "xa", unit, |
| 467 | DEV_BSIZE, |
| 468 | DEVSTAT_NO_ORDERED_TAGS, |
| 469 | DEVSTAT_TYPE_DIRECT | |
| 470 | DEVSTAT_TYPE_IF_OTHER, |
| 471 | DEVSTAT_PRIORITY_OTHER); |
| 472 | } |
| 473 | |
| 474 | sc->info.d_media_blksize = |
| 475 | msg->any.lnk_span.media.block.blksize; |
| 476 | if (sc->info.d_media_blksize <= 0) |
| 477 | sc->info.d_media_blksize = 1; |
| 478 | sc->info.d_media_blocks = |
| 479 | msg->any.lnk_span.media.block.bytes / |
| 480 | sc->info.d_media_blksize; |
| 481 | sc->info.d_dsflags = DSO_MBRQUIET | DSO_RAWPSIZE; |
| 482 | sc->info.d_secpertrack = 32; |
| 483 | sc->info.d_nheads = 64; |
| 484 | sc->info.d_secpercyl = sc->info.d_secpertrack * |
| 485 | sc->info.d_nheads; |
| 486 | sc->info.d_ncylinders = 0; |
| 487 | if (sc->fs_label[0]) |
| 488 | sc->info.d_serialno = sc->fs_label; |
| 489 | /* |
| 490 | * WARNING! disk_setdiskinfo() must be asynchronous |
| 491 | * because we are in the rxmsg thread. If |
| 492 | * it is synchronous and issues more disk |
| 493 | * I/Os, we will deadlock. |
| 494 | */ |
| 495 | kprintf("xdisk: A1\n"); |
| 496 | disk_setdiskinfo(&sc->disk, &sc->info); |
| 497 | xa_restart_deferred(sc); /* eats serializing */ |
| 498 | lockmgr(&sc->lk, LK_RELEASE); |
| 499 | } else { |
| 500 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 501 | ++sc->spancnt; |
| 502 | kprintf("xdisk: A2 (%d) ser=%d otag=%p\n", sc->spancnt, sc->serializing, sc->open_tag); |
| 503 | TAILQ_INSERT_TAIL(&sc->spanq, msg->state, user_entry); |
| 504 | msg->state->any.xa_sc = sc; |
| 505 | if (sc->serializing == 0 && sc->open_tag == NULL) { |
| 506 | sc->serializing = 1; |
| 507 | xa_restart_deferred(sc); /* eats serializing */ |
| 508 | } |
| 509 | lockmgr(&sc->lk, LK_RELEASE); |
| 510 | if (sc->dev && sc->dev->si_disk) { |
| 511 | kprintf("reprobe\n"); |
| 512 | disk_msg_send(DISK_DISK_REPROBE, |
| 513 | sc->dev->si_disk, |
| 514 | NULL); |
| 515 | } |
| 516 | } |
| 517 | kprintf("xdisk: sc %p spancnt %d\n", sc, sc->spancnt); |
| 518 | kdmsg_msg_result(msg, 0); |
| 519 | break; |
| 520 | case DMSG_LNK_SPAN | DMSGF_DELETE: |
| 521 | /* |
| 522 | * Manage the tracking node for the remote LNK_SPAN. |
| 523 | * |
| 524 | * Return a final result, closing our end of the transaction. |
| 525 | */ |
| 526 | sc = msg->state->any.xa_sc; |
| 527 | kprintf("xdisk: LINK_SPAN state %p delete for %s (sc=%p)\n", |
| 528 | msg->state, (sc ? sc->fs_label : "(null)"), sc); |
| 529 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 530 | msg->state->any.xa_sc = NULL; |
| 531 | TAILQ_REMOVE(&sc->spanq, msg->state, user_entry); |
| 532 | --sc->spancnt; |
| 533 | |
| 534 | kprintf("xdisk: sc %p spancnt %d\n", sc, sc->spancnt); |
| 535 | |
| 536 | /* |
| 537 | * Spans can come and go as the graph stabilizes, so if |
| 538 | * we lose a span along with sc->open_tag we may be able |
| 539 | * to restart the I/Os on a different span. |
| 540 | */ |
| 541 | if (sc->spancnt && |
| 542 | sc->serializing == 0 && sc->open_tag == NULL) { |
| 543 | sc->serializing = 1; |
| 544 | xa_restart_deferred(sc); |
| 545 | } |
| 546 | lockmgr(&sc->lk, LK_RELEASE); |
| 547 | kdmsg_msg_reply(msg, 0); |
| 548 | |
| 549 | #if 0 |
| 550 | /* |
| 551 | * Termination |
| 552 | */ |
| 553 | if (sc->spancnt == 0) |
| 554 | xa_terminate_check(sc); |
| 555 | #endif |
| 556 | break; |
| 557 | case DMSG_LNK_SPAN | DMSGF_DELETE | DMSGF_REPLY: |
| 558 | /* |
| 559 | * Ignore unimplemented streaming replies on our LNK_SPAN |
| 560 | * transaction. |
| 561 | */ |
| 562 | kprintf("xdisk: LINK_SPAN state %p delete+reply\n", |
| 563 | msg->state); |
| 564 | break; |
| 565 | case DMSG_LNK_SPAN | DMSGF_REPLY: |
| 566 | /* |
| 567 | * Ignore unimplemented streaming replies on our LNK_SPAN |
| 568 | * transaction. |
| 569 | */ |
| 570 | kprintf("xdisk: LINK_SPAN state %p reply\n", |
| 571 | msg->state); |
| 572 | break; |
| 573 | case DMSG_DBG_SHELL: |
| 574 | /* |
| 575 | * Execute shell command (not supported atm). |
| 576 | * |
| 577 | * This is a one-way packet but if not (e.g. if part of |
| 578 | * a streaming transaction), we will have already closed |
| 579 | * our end. |
| 580 | */ |
| 581 | kdmsg_msg_reply(msg, DMSG_ERR_NOSUPP); |
| 582 | break; |
| 583 | case DMSG_DBG_SHELL | DMSGF_REPLY: |
| 584 | /* |
| 585 | * Receive one or more replies to a shell command |
| 586 | * that we sent. Just dump it to the console. |
| 587 | * |
| 588 | * This is a one-way packet but if not (e.g. if |
| 589 | * part of a streaming transaction), we will have |
| 590 | * already closed our end. |
| 591 | */ |
| 592 | if (msg->aux_data) { |
| 593 | msg->aux_data[msg->aux_size - 1] = 0; |
| 594 | kprintf("xdisk: DEBUGMSG: %s\n", |
| 595 | msg->aux_data); |
| 596 | } |
| 597 | break; |
| 598 | default: |
| 599 | /* |
| 600 | * Unsupported one-way message, streaming message, or |
| 601 | * transaction. |
| 602 | * |
| 603 | * Terminate any unsupported transactions with an error |
| 604 | * and ignore any unsupported streaming messages. |
| 605 | * |
| 606 | * NOTE: This case also includes DMSG_LNK_ERROR messages |
| 607 | * which might be one-way, replying to those would |
| 608 | * cause an infinite ping-pong. |
| 609 | */ |
| 610 | if (msg->any.head.cmd & DMSGF_CREATE) |
| 611 | kdmsg_msg_reply(msg, DMSG_ERR_NOSUPP); |
| 612 | break; |
| 613 | } |
| 614 | lockmgr(&xdisk_lk, LK_RELEASE); |
| 615 | |
| 616 | return 0; |
| 617 | } |
| 618 | |
| 619 | /* |
| 620 | * Determine if we can destroy the xa_softc. |
| 621 | * |
| 622 | * Called with xdisk_lk held. |
| 623 | */ |
| 624 | static |
| 625 | void |
| 626 | xa_terminate_check(struct xa_softc *sc) |
| 627 | { |
| 628 | xa_tag_t *tag; |
| 629 | |
| 630 | /* |
| 631 | * Determine if we can destroy the softc. |
| 632 | */ |
| 633 | kprintf("xdisk: terminate check xa%d (%d,%d,%d) sc=%p ", |
| 634 | sc->unit, |
| 635 | sc->opencnt, sc->serializing, sc->spancnt, |
| 636 | sc); |
| 637 | |
| 638 | if (sc->opencnt || sc->serializing || sc->spancnt) { |
| 639 | kprintf("(leave intact)\n"); |
| 640 | return; |
| 641 | } |
| 642 | |
| 643 | /* |
| 644 | * Remove from device tree, a race with a new incoming span |
| 645 | * will create a new softc and disk. |
| 646 | */ |
| 647 | RB_REMOVE(xa_softc_tree, &xa_device_tree, sc); |
| 648 | |
| 649 | /* |
| 650 | * Device has to go first to prevent device ops races. |
| 651 | */ |
| 652 | if (sc->dev) { |
| 653 | disk_destroy(&sc->disk); |
| 654 | devstat_remove_entry(&sc->stats); |
| 655 | sc->dev->si_drv1 = NULL; |
| 656 | sc->dev = NULL; |
| 657 | } |
| 658 | |
| 659 | kprintf("(remove from tree)\n"); |
| 660 | sc->serializing = 1; |
| 661 | KKASSERT(sc->opencnt == 0); |
| 662 | KKASSERT(TAILQ_EMPTY(&sc->tag_pendq)); |
| 663 | |
| 664 | while ((tag = TAILQ_FIRST(&sc->tag_freeq)) != NULL) { |
| 665 | TAILQ_REMOVE(&sc->tag_freeq, tag, entry); |
| 666 | tag->sc = NULL; |
| 667 | kfree(tag, M_XDISK); |
| 668 | } |
| 669 | |
| 670 | kfree(sc, M_XDISK); |
| 671 | } |
| 672 | |
| 673 | /************************************************************************ |
| 674 | * XA DEVICE INTERFACE * |
| 675 | ************************************************************************/ |
| 676 | |
| 677 | static int |
| 678 | xa_open(struct dev_open_args *ap) |
| 679 | { |
| 680 | cdev_t dev = ap->a_head.a_dev; |
| 681 | xa_softc_t *sc; |
| 682 | int error; |
| 683 | |
| 684 | dev->si_bsize_phys = 512; |
| 685 | dev->si_bsize_best = 32768; |
| 686 | |
| 687 | /* |
| 688 | * Interlock open with opencnt, wait for attachment operations |
| 689 | * to finish. |
| 690 | */ |
| 691 | lockmgr(&xdisk_lk, LK_EXCLUSIVE); |
| 692 | again: |
| 693 | sc = dev->si_drv1; |
| 694 | if (sc == NULL) { |
| 695 | lockmgr(&xdisk_lk, LK_RELEASE); |
| 696 | return ENXIO; /* raced destruction */ |
| 697 | } |
| 698 | if (sc->serializing) { |
| 699 | tsleep(sc, 0, "xarace", hz / 10); |
| 700 | goto again; |
| 701 | } |
| 702 | sc->serializing = 1; |
| 703 | |
| 704 | /* |
| 705 | * Serialize initial open |
| 706 | */ |
| 707 | if (sc->opencnt++ > 0) { |
| 708 | sc->serializing = 0; |
| 709 | wakeup(sc); |
| 710 | lockmgr(&xdisk_lk, LK_RELEASE); |
| 711 | return(0); |
| 712 | } |
| 713 | |
| 714 | /* |
| 715 | * Issue BLK_OPEN if necessary. ENXIO is returned if we have trouble. |
| 716 | */ |
| 717 | if (sc->open_tag == NULL) { |
| 718 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 719 | xa_restart_deferred(sc); /* eats serializing */ |
| 720 | lockmgr(&sc->lk, LK_RELEASE); |
| 721 | } else { |
| 722 | sc->serializing = 0; |
| 723 | wakeup(sc); |
| 724 | } |
| 725 | lockmgr(&xdisk_lk, LK_RELEASE); |
| 726 | |
| 727 | /* |
| 728 | * Wait for completion of the BLK_OPEN |
| 729 | */ |
| 730 | lockmgr(&xdisk_lk, LK_EXCLUSIVE); |
| 731 | while (sc->serializing) |
| 732 | lksleep(sc, &xdisk_lk, 0, "xaopen", hz); |
| 733 | |
| 734 | error = sc->last_error; |
| 735 | if (error) { |
| 736 | KKASSERT(sc->opencnt > 0); |
| 737 | --sc->opencnt; |
| 738 | xa_terminate_check(sc); |
| 739 | sc = NULL; /* sc may be invalid now */ |
| 740 | } |
| 741 | lockmgr(&xdisk_lk, LK_RELEASE); |
| 742 | |
| 743 | return (error); |
| 744 | } |
| 745 | |
| 746 | static int |
| 747 | xa_close(struct dev_close_args *ap) |
| 748 | { |
| 749 | cdev_t dev = ap->a_head.a_dev; |
| 750 | xa_softc_t *sc; |
| 751 | xa_tag_t *tag; |
| 752 | |
| 753 | sc = dev->si_drv1; |
| 754 | if (sc == NULL) |
| 755 | return ENXIO; /* raced destruction */ |
| 756 | lockmgr(&xdisk_lk, LK_EXCLUSIVE); |
| 757 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 758 | |
| 759 | /* |
| 760 | * NOTE: Clearing open_tag allows a concurrent open to re-open |
| 761 | * the device and prevents autonomous completion of the tag. |
| 762 | */ |
| 763 | if (sc->opencnt == 1 && sc->open_tag) { |
| 764 | tag = sc->open_tag; |
| 765 | sc->open_tag = NULL; |
| 766 | lockmgr(&sc->lk, LK_RELEASE); |
| 767 | kdmsg_state_reply(tag->state, 0); /* close our side */ |
| 768 | xa_wait(tag); /* wait on remote */ |
| 769 | } else { |
| 770 | lockmgr(&sc->lk, LK_RELEASE); |
| 771 | } |
| 772 | KKASSERT(sc->opencnt > 0); |
| 773 | --sc->opencnt; |
| 774 | xa_terminate_check(sc); |
| 775 | lockmgr(&xdisk_lk, LK_RELEASE); |
| 776 | |
| 777 | return(0); |
| 778 | } |
| 779 | |
| 780 | static int |
| 781 | xa_strategy(struct dev_strategy_args *ap) |
| 782 | { |
| 783 | xa_softc_t *sc = ap->a_head.a_dev->si_drv1; |
| 784 | xa_tag_t *tag; |
| 785 | struct bio *bio = ap->a_bio; |
| 786 | |
| 787 | devstat_start_transaction(&sc->stats); |
| 788 | atomic_add_int(&xa_active, 1); |
| 789 | xa_last = bio->bio_offset; |
| 790 | |
| 791 | /* |
| 792 | * If no tags are available NULL is returned and the bio is |
| 793 | * placed on sc->bioq. |
| 794 | */ |
| 795 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 796 | tag = xa_setup_cmd(sc, bio); |
| 797 | if (tag) |
| 798 | xa_start(tag, NULL, 1); |
| 799 | lockmgr(&sc->lk, LK_RELEASE); |
| 800 | |
| 801 | return(0); |
| 802 | } |
| 803 | |
| 804 | static int |
| 805 | xa_ioctl(struct dev_ioctl_args *ap) |
| 806 | { |
| 807 | return(ENOTTY); |
| 808 | } |
| 809 | |
| 810 | static int |
| 811 | xa_size(struct dev_psize_args *ap) |
| 812 | { |
| 813 | struct xa_softc *sc; |
| 814 | |
| 815 | if ((sc = ap->a_head.a_dev->si_drv1) == NULL) |
| 816 | return (ENXIO); |
| 817 | ap->a_result = sc->info.d_media_blocks; |
| 818 | return (0); |
| 819 | } |
| 820 | |
| 821 | /************************************************************************ |
| 822 | * XA BLOCK PROTOCOL STATE MACHINE * |
| 823 | ************************************************************************ |
| 824 | * |
| 825 | * Implement tag/msg setup and related functions. |
| 826 | * Called with sc->lk held. |
| 827 | */ |
| 828 | static xa_tag_t * |
| 829 | xa_setup_cmd(xa_softc_t *sc, struct bio *bio) |
| 830 | { |
| 831 | xa_tag_t *tag; |
| 832 | |
| 833 | /* |
| 834 | * Only get a tag if we have a valid virtual circuit to the server. |
| 835 | */ |
| 836 | if ((tag = TAILQ_FIRST(&sc->tag_freeq)) != NULL) { |
| 837 | TAILQ_REMOVE(&sc->tag_freeq, tag, entry); |
| 838 | tag->bio = bio; |
| 839 | TAILQ_INSERT_TAIL(&sc->tag_pendq, tag, entry); |
| 840 | } |
| 841 | |
| 842 | /* |
| 843 | * If we can't dispatch now and this is a bio, queue it for later. |
| 844 | */ |
| 845 | if (tag == NULL && bio) { |
| 846 | TAILQ_INSERT_TAIL(&sc->bioq, bio, bio_act); |
| 847 | } |
| 848 | |
| 849 | return (tag); |
| 850 | } |
| 851 | |
| 852 | /* |
| 853 | * Called with sc->lk held |
| 854 | */ |
| 855 | static void |
| 856 | xa_start(xa_tag_t *tag, kdmsg_msg_t *msg, int async) |
| 857 | { |
| 858 | xa_softc_t *sc = tag->sc; |
| 859 | |
| 860 | tag->done = 0; |
| 861 | tag->async = async; |
| 862 | tag->status.head.error = DMSG_ERR_IO; /* fallback error */ |
| 863 | |
| 864 | if (msg == NULL) { |
| 865 | struct bio *bio; |
| 866 | struct buf *bp; |
| 867 | kdmsg_state_t *trans; |
| 868 | |
| 869 | if (sc->opencnt == 0 || sc->open_tag == NULL) { |
| 870 | TAILQ_FOREACH(trans, &sc->spanq, user_entry) { |
| 871 | if ((trans->rxcmd & DMSGF_DELETE) == 0) |
| 872 | break; |
| 873 | } |
| 874 | } else { |
| 875 | trans = sc->open_tag->state; |
| 876 | } |
| 877 | if (trans == NULL) |
| 878 | goto skip; |
| 879 | |
| 880 | KKASSERT(tag->bio); |
| 881 | bio = tag->bio; |
| 882 | bp = bio->bio_buf; |
| 883 | |
| 884 | switch(bp->b_cmd) { |
| 885 | case BUF_CMD_READ: |
| 886 | msg = kdmsg_msg_alloc(trans, |
| 887 | DMSG_BLK_READ | |
| 888 | DMSGF_CREATE | |
| 889 | DMSGF_DELETE, |
| 890 | xa_bio_completion, tag); |
| 891 | msg->any.blk_read.keyid = sc->keyid; |
| 892 | msg->any.blk_read.offset = bio->bio_offset; |
| 893 | msg->any.blk_read.bytes = bp->b_bcount; |
| 894 | break; |
| 895 | case BUF_CMD_WRITE: |
| 896 | msg = kdmsg_msg_alloc(trans, |
| 897 | DMSG_BLK_WRITE | |
| 898 | DMSGF_CREATE | DMSGF_DELETE, |
| 899 | xa_bio_completion, tag); |
| 900 | msg->any.blk_write.keyid = sc->keyid; |
| 901 | msg->any.blk_write.offset = bio->bio_offset; |
| 902 | msg->any.blk_write.bytes = bp->b_bcount; |
| 903 | msg->aux_data = bp->b_data; |
| 904 | msg->aux_size = bp->b_bcount; |
| 905 | break; |
| 906 | case BUF_CMD_FLUSH: |
| 907 | msg = kdmsg_msg_alloc(trans, |
| 908 | DMSG_BLK_FLUSH | |
| 909 | DMSGF_CREATE | DMSGF_DELETE, |
| 910 | xa_bio_completion, tag); |
| 911 | msg->any.blk_flush.keyid = sc->keyid; |
| 912 | msg->any.blk_flush.offset = bio->bio_offset; |
| 913 | msg->any.blk_flush.bytes = bp->b_bcount; |
| 914 | break; |
| 915 | case BUF_CMD_FREEBLKS: |
| 916 | msg = kdmsg_msg_alloc(trans, |
| 917 | DMSG_BLK_FREEBLKS | |
| 918 | DMSGF_CREATE | DMSGF_DELETE, |
| 919 | xa_bio_completion, tag); |
| 920 | msg->any.blk_freeblks.keyid = sc->keyid; |
| 921 | msg->any.blk_freeblks.offset = bio->bio_offset; |
| 922 | msg->any.blk_freeblks.bytes = bp->b_bcount; |
| 923 | break; |
| 924 | default: |
| 925 | bp->b_flags |= B_ERROR; |
| 926 | bp->b_error = EIO; |
| 927 | devstat_end_transaction_buf(&sc->stats, bp); |
| 928 | atomic_add_int(&xa_active, -1); |
| 929 | biodone(bio); |
| 930 | tag->bio = NULL; |
| 931 | break; |
| 932 | } |
| 933 | } |
| 934 | |
| 935 | /* |
| 936 | * If no msg was allocated we likely could not find a good span. |
| 937 | */ |
| 938 | skip: |
| 939 | if (msg) { |
| 940 | /* |
| 941 | * Message was passed in or constructed. |
| 942 | */ |
| 943 | tag->state = msg->state; |
| 944 | lockmgr(&sc->lk, LK_RELEASE); |
| 945 | kdmsg_msg_write(msg); |
| 946 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 947 | } else if (tag->bio && |
| 948 | (tag->bio->bio_buf->b_flags & B_FAILONDIS) == 0) { |
| 949 | /* |
| 950 | * No spans available but BIO is not allowed to fail |
| 951 | * on connectivity problems. Requeue the BIO. |
| 952 | */ |
| 953 | TAILQ_INSERT_TAIL(&sc->bioq, tag->bio, bio_act); |
| 954 | tag->bio = NULL; |
| 955 | lockmgr(&sc->lk, LK_RELEASE); |
| 956 | xa_done(tag, 1); |
| 957 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 958 | } else { |
| 959 | /* |
| 960 | * No spans available, bio is allowed to fail. |
| 961 | */ |
| 962 | lockmgr(&sc->lk, LK_RELEASE); |
| 963 | tag->status.head.error = DMSG_ERR_IO; |
| 964 | xa_done(tag, 1); |
| 965 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 966 | } |
| 967 | } |
| 968 | |
| 969 | static uint32_t |
| 970 | xa_wait(xa_tag_t *tag) |
| 971 | { |
| 972 | xa_softc_t *sc = tag->sc; |
| 973 | uint32_t error; |
| 974 | |
| 975 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 976 | tag->waiting = 1; |
| 977 | while (tag->done == 0) |
| 978 | lksleep(tag, &sc->lk, 0, "xawait", 0); |
| 979 | lockmgr(&sc->lk, LK_RELEASE); |
| 980 | |
| 981 | error = tag->status.head.error; |
| 982 | tag->waiting = 0; |
| 983 | xa_release(tag, 0); |
| 984 | |
| 985 | return error; |
| 986 | } |
| 987 | |
| 988 | static void |
| 989 | xa_done(xa_tag_t *tag, int wasbio) |
| 990 | { |
| 991 | KKASSERT(tag->bio == NULL); |
| 992 | |
| 993 | tag->state = NULL; |
| 994 | tag->done = 1; |
| 995 | if (tag->waiting) |
| 996 | wakeup(tag); |
| 997 | if (tag->async) |
| 998 | xa_release(tag, wasbio); |
| 999 | } |
| 1000 | |
| 1001 | /* |
| 1002 | * Release a tag. If everything looks ok and there are pending BIOs |
| 1003 | * (due to all tags in-use), we can use the tag to start the next BIO. |
| 1004 | * Do not try to restart if the connection is currently failed. |
| 1005 | */ |
| 1006 | static |
| 1007 | void |
| 1008 | xa_release(xa_tag_t *tag, int wasbio) |
| 1009 | { |
| 1010 | xa_softc_t *sc = tag->sc; |
| 1011 | struct bio *bio; |
| 1012 | |
| 1013 | if ((bio = tag->bio) != NULL) { |
| 1014 | struct buf *bp = bio->bio_buf; |
| 1015 | |
| 1016 | bp->b_error = EIO; |
| 1017 | bp->b_flags |= B_ERROR; |
| 1018 | devstat_end_transaction_buf(&sc->stats, bp); |
| 1019 | atomic_add_int(&xa_active, -1); |
| 1020 | biodone(bio); |
| 1021 | tag->bio = NULL; |
| 1022 | } |
| 1023 | |
| 1024 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 1025 | |
| 1026 | if (wasbio && sc->open_tag && |
| 1027 | (bio = TAILQ_FIRST(&sc->bioq)) != NULL) { |
| 1028 | TAILQ_REMOVE(&sc->bioq, bio, bio_act); |
| 1029 | tag->bio = bio; |
| 1030 | xa_start(tag, NULL, 1); |
| 1031 | } else { |
| 1032 | TAILQ_REMOVE(&sc->tag_pendq, tag, entry); |
| 1033 | TAILQ_INSERT_TAIL(&sc->tag_freeq, tag, entry); |
| 1034 | } |
| 1035 | lockmgr(&sc->lk, LK_RELEASE); |
| 1036 | } |
| 1037 | |
| 1038 | /* |
| 1039 | * Handle messages under the BLKOPEN transaction. |
| 1040 | */ |
| 1041 | static int |
| 1042 | xa_sync_completion(kdmsg_state_t *state, kdmsg_msg_t *msg) |
| 1043 | { |
| 1044 | xa_tag_t *tag = state->any.any; |
| 1045 | xa_softc_t *sc; |
| 1046 | struct bio *bio; |
| 1047 | |
| 1048 | /* |
| 1049 | * If the tag has been cleaned out we already closed our side |
| 1050 | * of the transaction and we are waiting for the other side to |
| 1051 | * close. |
| 1052 | */ |
| 1053 | kprintf("xa_sync_completion: tag %p msg %08x state %p\n", |
| 1054 | tag, msg->any.head.cmd, msg->state); |
| 1055 | |
| 1056 | if (tag == NULL) { |
| 1057 | if (msg->any.head.cmd & DMSGF_CREATE) |
| 1058 | kdmsg_state_reply(state, DMSG_ERR_LOSTLINK); |
| 1059 | return 0; |
| 1060 | } |
| 1061 | sc = tag->sc; |
| 1062 | |
| 1063 | /* |
| 1064 | * Validate the tag |
| 1065 | */ |
| 1066 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 1067 | |
| 1068 | /* |
| 1069 | * Handle initial response to our open and restart any deferred |
| 1070 | * BIOs on success. |
| 1071 | * |
| 1072 | * NOTE: DELETE may also be set. |
| 1073 | */ |
| 1074 | if (msg->any.head.cmd & DMSGF_CREATE) { |
| 1075 | switch(msg->any.head.cmd & DMSGF_CMDSWMASK) { |
| 1076 | case DMSG_LNK_ERROR | DMSGF_REPLY: |
| 1077 | bzero(&tag->status, sizeof(tag->status)); |
| 1078 | tag->status.head = msg->any.head; |
| 1079 | break; |
| 1080 | case DMSG_BLK_ERROR | DMSGF_REPLY: |
| 1081 | tag->status = msg->any.blk_error; |
| 1082 | break; |
| 1083 | } |
| 1084 | sc->last_error = tag->status.head.error; |
| 1085 | kprintf("xdisk: blk_open completion status %d\n", |
| 1086 | sc->last_error); |
| 1087 | if (sc->last_error == 0) { |
| 1088 | while ((bio = TAILQ_FIRST(&sc->bioq)) != NULL) { |
| 1089 | tag = xa_setup_cmd(sc, NULL); |
| 1090 | if (tag == NULL) |
| 1091 | break; |
| 1092 | TAILQ_REMOVE(&sc->bioq, bio, bio_act); |
| 1093 | tag->bio = bio; |
| 1094 | xa_start(tag, NULL, 1); |
| 1095 | } |
| 1096 | } |
| 1097 | sc->serializing = 0; |
| 1098 | wakeup(sc); |
| 1099 | } |
| 1100 | |
| 1101 | /* |
| 1102 | * Handle unexpected termination (or lost comm channel) from other |
| 1103 | * side. Autonomous completion only if open_tag matches, |
| 1104 | * otherwise another thread is probably waiting on the tag. |
| 1105 | * |
| 1106 | * (see xa_close() for other interactions) |
| 1107 | */ |
| 1108 | if (msg->any.head.cmd & DMSGF_DELETE) { |
| 1109 | kdmsg_state_reply(tag->state, 0); |
| 1110 | if (sc->open_tag == tag) { |
| 1111 | sc->open_tag = NULL; |
| 1112 | xa_done(tag, 0); |
| 1113 | } else { |
| 1114 | tag->async = 0; |
| 1115 | xa_done(tag, 0); |
| 1116 | } |
| 1117 | } |
| 1118 | lockmgr(&sc->lk, LK_RELEASE); |
| 1119 | |
| 1120 | return (0); |
| 1121 | } |
| 1122 | |
| 1123 | static int |
| 1124 | xa_bio_completion(kdmsg_state_t *state, kdmsg_msg_t *msg) |
| 1125 | { |
| 1126 | xa_tag_t *tag = state->any.any; |
| 1127 | xa_softc_t *sc = tag->sc; |
| 1128 | struct bio *bio; |
| 1129 | struct buf *bp; |
| 1130 | |
| 1131 | /* |
| 1132 | * Get the bio from the tag. If no bio is present we just do |
| 1133 | * 'done' handling. |
| 1134 | */ |
| 1135 | if ((bio = tag->bio) == NULL) |
| 1136 | goto handle_done; |
| 1137 | bp = bio->bio_buf; |
| 1138 | |
| 1139 | /* |
| 1140 | * Process return status |
| 1141 | */ |
| 1142 | switch(msg->any.head.cmd & DMSGF_CMDSWMASK) { |
| 1143 | case DMSG_LNK_ERROR | DMSGF_REPLY: |
| 1144 | bzero(&tag->status, sizeof(tag->status)); |
| 1145 | tag->status.head = msg->any.head; |
| 1146 | if (tag->status.head.error) |
| 1147 | tag->status.resid = bp->b_bcount; |
| 1148 | else |
| 1149 | tag->status.resid = 0; |
| 1150 | break; |
| 1151 | case DMSG_BLK_ERROR | DMSGF_REPLY: |
| 1152 | tag->status = msg->any.blk_error; |
| 1153 | break; |
| 1154 | } |
| 1155 | |
| 1156 | /* |
| 1157 | * If the device is open stall the bio on DMSG errors. If an |
| 1158 | * actual I/O error occured on the remote device, DMSG_ERR_IO |
| 1159 | * will be returned. |
| 1160 | */ |
| 1161 | if (tag->status.head.error && |
| 1162 | (msg->any.head.cmd & DMSGF_DELETE) && sc->opencnt) { |
| 1163 | if (tag->status.head.error != DMSG_ERR_IO) |
| 1164 | goto handle_repend; |
| 1165 | } |
| 1166 | |
| 1167 | /* |
| 1168 | * Process bio completion |
| 1169 | * |
| 1170 | * For reads any returned data is zero-extended if necessary, so |
| 1171 | * the server can short-cut any all-zeros reads if it desires. |
| 1172 | */ |
| 1173 | switch(bp->b_cmd) { |
| 1174 | case BUF_CMD_READ: |
| 1175 | if (msg->aux_data && msg->aux_size) { |
| 1176 | if (msg->aux_size < bp->b_bcount) { |
| 1177 | bcopy(msg->aux_data, bp->b_data, msg->aux_size); |
| 1178 | bzero(bp->b_data + msg->aux_size, |
| 1179 | bp->b_bcount - msg->aux_size); |
| 1180 | } else { |
| 1181 | bcopy(msg->aux_data, bp->b_data, bp->b_bcount); |
| 1182 | } |
| 1183 | } else { |
| 1184 | bzero(bp->b_data, bp->b_bcount); |
| 1185 | } |
| 1186 | /* fall through */ |
| 1187 | case BUF_CMD_WRITE: |
| 1188 | case BUF_CMD_FLUSH: |
| 1189 | case BUF_CMD_FREEBLKS: |
| 1190 | default: |
| 1191 | if (tag->status.resid > bp->b_bcount) |
| 1192 | tag->status.resid = bp->b_bcount; |
| 1193 | bp->b_resid = tag->status.resid; |
| 1194 | if (tag->status.head.error != 0) { |
| 1195 | bp->b_error = EIO; |
| 1196 | bp->b_flags |= B_ERROR; |
| 1197 | } else { |
| 1198 | bp->b_resid = 0; |
| 1199 | } |
| 1200 | devstat_end_transaction_buf(&sc->stats, bp); |
| 1201 | atomic_add_int(&xa_active, -1); |
| 1202 | biodone(bio); |
| 1203 | tag->bio = NULL; |
| 1204 | break; |
| 1205 | } |
| 1206 | |
| 1207 | /* |
| 1208 | * Handle completion of the transaction. If the bioq is not empty |
| 1209 | * we can initiate another bio on the same tag. |
| 1210 | * |
| 1211 | * NOTE: Most of our transactions will be single-message |
| 1212 | * CREATE+DELETEs, so we won't have to terminate the |
| 1213 | * transaction separately, here. But just in case they |
| 1214 | * aren't be sure to terminate the transaction. |
| 1215 | */ |
| 1216 | handle_done: |
| 1217 | if (msg->any.head.cmd & DMSGF_DELETE) { |
| 1218 | xa_done(tag, 1); |
| 1219 | if ((state->txcmd & DMSGF_DELETE) == 0) |
| 1220 | kdmsg_msg_reply(msg, 0); |
| 1221 | } |
| 1222 | return (0); |
| 1223 | |
| 1224 | /* |
| 1225 | * Handle the case where the transaction failed due to a |
| 1226 | * connectivity issue. The tag is put away with wasbio=0 |
| 1227 | * and we put the BIO back onto the bioq for a later restart. |
| 1228 | * |
| 1229 | * probe I/Os (where the device is not open) will be failed |
| 1230 | * instead of requeued. |
| 1231 | */ |
| 1232 | handle_repend: |
| 1233 | tag->bio = NULL; |
| 1234 | if (bio->bio_buf->b_flags & B_FAILONDIS) { |
| 1235 | kprintf("xa_strategy: disconnected, fail bp %p\n", |
| 1236 | bio->bio_buf); |
| 1237 | bio->bio_buf->b_error = ENXIO; |
| 1238 | bio->bio_buf->b_flags |= B_ERROR; |
| 1239 | biodone(bio); |
| 1240 | bio = NULL; |
| 1241 | kprintf("BIO CIRC FAILURE, FAIL BIO %p\n", bio); |
| 1242 | } else { |
| 1243 | kprintf("BIO CIRC FAILURE, REPEND BIO %p\n", bio); |
| 1244 | } |
| 1245 | xa_done(tag, 0); |
| 1246 | if ((state->txcmd & DMSGF_DELETE) == 0) |
| 1247 | kdmsg_msg_reply(msg, 0); |
| 1248 | |
| 1249 | /* |
| 1250 | * Requeue the bio |
| 1251 | */ |
| 1252 | if (bio) { |
| 1253 | lockmgr(&sc->lk, LK_EXCLUSIVE); |
| 1254 | TAILQ_INSERT_TAIL(&sc->bioq, bio, bio_act); |
| 1255 | lockmgr(&sc->lk, LK_RELEASE); |
| 1256 | } |
| 1257 | return (0); |
| 1258 | } |
| 1259 | |
| 1260 | /* |
| 1261 | * Restart as much deferred I/O as we can. The serializer is set and we |
| 1262 | * eat it (clear it) when done. |
| 1263 | * |
| 1264 | * Called with sc->lk held |
| 1265 | */ |
| 1266 | static |
| 1267 | void |
| 1268 | xa_restart_deferred(xa_softc_t *sc) |
| 1269 | { |
| 1270 | kdmsg_state_t *span; |
| 1271 | kdmsg_msg_t *msg; |
| 1272 | xa_tag_t *tag; |
| 1273 | int error; |
| 1274 | |
| 1275 | KKASSERT(sc->serializing); |
| 1276 | |
| 1277 | /* |
| 1278 | * Determine if a restart is needed. |
| 1279 | */ |
| 1280 | if (sc->opencnt == 0) { |
| 1281 | /* |
| 1282 | * Device is not open, nothing to do, eat serializing. |
| 1283 | */ |
| 1284 | sc->serializing = 0; |
| 1285 | wakeup(sc); |
| 1286 | } else if (sc->open_tag == NULL) { |
| 1287 | /* |
| 1288 | * BLK_OPEN required before we can restart any BIOs. |
| 1289 | * Select the best LNK_SPAN to issue the BLK_OPEN under. |
| 1290 | * |
| 1291 | * serializing interlocks waiting open()s. |
| 1292 | */ |
| 1293 | error = 0; |
| 1294 | TAILQ_FOREACH(span, &sc->spanq, user_entry) { |
| 1295 | if ((span->rxcmd & DMSGF_DELETE) == 0) |
| 1296 | break; |
| 1297 | } |
| 1298 | if (span == NULL) |
| 1299 | error = ENXIO; |
| 1300 | |
| 1301 | if (error == 0) { |
| 1302 | tag = xa_setup_cmd(sc, NULL); |
| 1303 | if (tag == NULL) |
| 1304 | error = ENXIO; |
| 1305 | } |
| 1306 | if (error == 0) { |
| 1307 | sc->open_tag = tag; |
| 1308 | msg = kdmsg_msg_alloc(span, |
| 1309 | DMSG_BLK_OPEN | |
| 1310 | DMSGF_CREATE, |
| 1311 | xa_sync_completion, tag); |
| 1312 | msg->any.blk_open.modes = DMSG_BLKOPEN_RD; |
| 1313 | kprintf("xdisk: BLK_OPEN tag %p state %p " |
| 1314 | "span-state %p\n", |
| 1315 | tag, msg->state, span); |
| 1316 | xa_start(tag, msg, 0); |
| 1317 | } |
| 1318 | if (error) { |
| 1319 | sc->serializing = 0; |
| 1320 | wakeup(sc); |
| 1321 | } |
| 1322 | /* else leave serializing set until BLK_OPEN response */ |
| 1323 | } else { |
| 1324 | /* nothing to do */ |
| 1325 | sc->serializing = 0; |
| 1326 | wakeup(sc); |
| 1327 | } |
| 1328 | } |