1 /****************************************************************************** 2 * blkif.h 3 * 4 * Unified block-device I/O interface for Xen guest OSes. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to 8 * deal in the Software without restriction, including without limitation the 9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 10 * sell copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 22 * DEALINGS IN THE SOFTWARE. 23 * 24 * Copyright (c) 2003-2004, Keir Fraser 25 * Copyright (c) 2012, Spectra Logic Corporation 26 */ 27 28 #ifndef __XEN_PUBLIC_IO_BLKIF_H__ 29 #define __XEN_PUBLIC_IO_BLKIF_H__ 30 31 #include "ring.h" 32 #include "../grant_table.h" 33 34 /* 35 * Front->back notifications: When enqueuing a new request, sending a 36 * notification can be made conditional on req_event (i.e., the generic 37 * hold-off mechanism provided by the ring macros). Backends must set 38 * req_event appropriately (e.g., using RING_FINAL_CHECK_FOR_REQUESTS()). 39 * 40 * Back->front notifications: When enqueuing a new response, sending a 41 * notification can be made conditional on rsp_event (i.e., the generic 42 * hold-off mechanism provided by the ring macros). Frontends must set 43 * rsp_event appropriately (e.g., using RING_FINAL_CHECK_FOR_RESPONSES()). 44 */ 45 46 #ifndef blkif_vdev_t 47 #define blkif_vdev_t UINT16 48 #endif 49 #define blkif_sector_t UINT64 50 51 /* 52 * Feature and Parameter Negotiation 53 * ================================= 54 * The two halves of a Xen block driver utilize nodes within the XenStore to 55 * communicate capabilities and to negotiate operating parameters. This 56 * section enumerates these nodes which reside in the respective front and 57 * backend portions of the XenStore, following the XenBus convention. 58 * 59 * All data in the XenStore is stored as strings. Nodes specifying numeric 60 * values are encoded in decimal. Integer value ranges listed below are 61 * expressed as fixed sized integer types capable of storing the conversion 62 * of a properly formated node string, without loss of information. 63 * 64 * Any specified default value is in effect if the corresponding XenBus node 65 * is not present in the XenStore. 66 * 67 * XenStore nodes in sections marked "PRIVATE" are solely for use by the 68 * driver side whose XenBus tree contains them. 69 * 70 * XenStore nodes marked "DEPRECATED" in their notes section should only be 71 * used to provide interoperability with legacy implementations. 72 * 73 * See the XenBus state transition diagram below for details on when XenBus 74 * nodes must be published and when they can be queried. 75 * 76 ***************************************************************************** 77 * Backend XenBus Nodes 78 ***************************************************************************** 79 * 80 *------------------ Backend Device Identification (PRIVATE) ------------------ 81 * 82 * mode 83 * Values: "r" (read only), "w" (writable) 84 * 85 * The read or write access permissions to the backing store to be 86 * granted to the frontend. 87 * 88 * params 89 * Values: string 90 * 91 * A free formatted string providing sufficient information for the 92 * backend driver to open the backing device. (e.g. the path to the 93 * file or block device representing the backing store.) 94 * 95 * type 96 * Values: "file", "phy", "tap" 97 * 98 * The type of the backing device/object. 99 * 100 *--------------------------------- Features --------------------------------- 101 * 102 * feature-barrier 103 * Values: 0/1 (boolean) 104 * Default Value: 0 105 * 106 * A value of "1" indicates that the backend can process requests 107 * containing the BLKIF_OP_WRITE_BARRIER request opcode. Requests 108 * of this type may still be returned at any time with the 109 * BLKIF_RSP_EOPNOTSUPP result code. 110 * 111 * feature-flush-cache 112 * Values: 0/1 (boolean) 113 * Default Value: 0 114 * 115 * A value of "1" indicates that the backend can process requests 116 * containing the BLKIF_OP_FLUSH_DISKCACHE request opcode. Requests 117 * of this type may still be returned at any time with the 118 * BLKIF_RSP_EOPNOTSUPP result code. 119 * 120 * feature-discard 121 * Values: 0/1 (boolean) 122 * Default Value: 0 123 * 124 * A value of "1" indicates that the backend can process requests 125 * containing the BLKIF_OP_DISCARD request opcode. Requests 126 * of this type may still be returned at any time with the 127 * BLKIF_RSP_EOPNOTSUPP result code. 128 * 129 * feature-persistent 130 * Values: 0/1 (boolean) 131 * Default Value: 0 132 * Notes: 7 133 * 134 * A value of "1" indicates that the backend can keep the grants used 135 * by the frontend driver mapped, so the same set of grants should be 136 * used in all transactions. The maximum number of grants the backend 137 * can map persistently depends on the implementation, but ideally it 138 * should be RING_SIZE * BLKIF_MAX_SEGMENTS_PER_REQUEST. Using this 139 * feature the backend doesn't need to unmap each grant, preventing 140 * costly TLB flushes. The backend driver should only map grants 141 * persistently if the frontend supports it. If a backend driver chooses 142 * to use the persistent protocol when the frontend doesn't support it, 143 * it will probably hit the maximum number of persistently mapped grants 144 * (due to the fact that the frontend won't be reusing the same grants), 145 * and fall back to non-persistent mode. Backend implementations may 146 * shrink or expand the number of persistently mapped grants without 147 * notifying the frontend depending on memory constraints (this might 148 * cause a performance degradation). 149 * 150 * If a backend driver wants to limit the maximum number of persistently 151 * mapped grants to a value less than RING_SIZE * 152 * BLKIF_MAX_SEGMENTS_PER_REQUEST a LRU strategy should be used to 153 * discard the grants that are less commonly used. Using a LRU in the 154 * backend driver paired with a LIFO queue in the frontend will 155 * allow us to have better performance in this scenario. 156 * 157 *----------------------- Request Transport Parameters ------------------------ 158 * 159 * max-ring-page-order 160 * Values: <UINT32> 161 * Default Value: 0 162 * Notes: 1, 3 163 * 164 * The maximum supported size of the request ring buffer in units of 165 * lb(machine pages). (e.g. 0 == 1 page, 1 = 2 pages, 2 == 4 pages, 166 * etc.). 167 * 168 * max-ring-pages 169 * Values: <UINT32> 170 * Default Value: 1 171 * Notes: DEPRECATED, 2, 3 172 * 173 * The maximum supported size of the request ring buffer in units of 174 * machine pages. The value must be a power of 2. 175 * 176 *------------------------- Backend Device Properties ------------------------- 177 * 178 * discard-alignment 179 * Values: <UINT32> 180 * Default Value: 0 181 * Notes: 4, 5 182 * 183 * The offset, in bytes from the beginning of the virtual block device, 184 * to the first, addressable, discard extent on the underlying device. 185 * 186 * discard-granularity 187 * Values: <UINT32> 188 * Default Value: <"sector-size"> 189 * Notes: 4 190 * 191 * The size, in bytes, of the individually addressable discard extents 192 * of the underlying device. 193 * 194 * discard-secure 195 * Values: 0/1 (boolean) 196 * Default Value: 0 197 * Notes: 10 198 * 199 * A value of "1" indicates that the backend can process BLKIF_OP_DISCARD 200 * requests with the BLKIF_DISCARD_SECURE flag set. 201 * 202 * info 203 * Values: <UINT32> (bitmap) 204 * 205 * A collection of bit flags describing attributes of the backing 206 * device. The VDISK_* macros define the meaning of each bit 207 * location. 208 * 209 * sector-size 210 * Values: <UINT32> 211 * 212 * The logical sector size, in bytes, of the backend device. 213 * 214 * physical-sector-size 215 * Values: <UINT32> 216 * 217 * The physical sector size, in bytes, of the backend device. 218 * 219 * sectors 220 * Values: <UINT64> 221 * 222 * The size of the backend device, expressed in units of its logical 223 * sector size ("sector-size"). 224 * 225 ***************************************************************************** 226 * Frontend XenBus Nodes 227 ***************************************************************************** 228 * 229 *----------------------- Request Transport Parameters ----------------------- 230 * 231 * event-channel 232 * Values: <UINT32> 233 * 234 * The identifier of the Xen event channel used to signal activity 235 * in the ring buffer. 236 * 237 * ring-ref 238 * Values: <UINT32> 239 * Notes: 6 240 * 241 * The Xen grant reference granting permission for the backend to map 242 * the sole page in a single page sized ring buffer. 243 * 244 * ring-ref%u 245 * Values: <UINT32> 246 * Notes: 6 247 * 248 * For a frontend providing a multi-page ring, a "number of ring pages" 249 * sized list of nodes, each containing a Xen grant reference granting 250 * permission for the backend to map the page of the ring located 251 * at page index "%u". Page indexes are zero based. 252 * 253 * protocol 254 * Values: string (XEN_IO_PROTO_ABI_*) 255 * Default Value: XEN_IO_PROTO_ABI_NATIVE 256 * 257 * The machine ABI rules governing the format of all ring request and 258 * response structures. 259 * 260 * ring-page-order 261 * Values: <UINT32> 262 * Default Value: 0 263 * Maximum Value: MAX(ffs(max-ring-pages) - 1, max-ring-page-order) 264 * Notes: 1, 3 265 * 266 * The size of the frontend allocated request ring buffer in units 267 * of lb(machine pages). (e.g. 0 == 1 page, 1 = 2 pages, 2 == 4 pages, 268 * etc.). 269 * 270 * num-ring-pages 271 * Values: <UINT32> 272 * Default Value: 1 273 * Maximum Value: MAX(max-ring-pages,(0x1 << max-ring-page-order)) 274 * Notes: DEPRECATED, 2, 3 275 * 276 * The size of the frontend allocated request ring buffer in units of 277 * machine pages. The value must be a power of 2. 278 * 279 * feature-persistent 280 * Values: 0/1 (boolean) 281 * Default Value: 0 282 * Notes: 7, 8, 9 283 * 284 * A value of "1" indicates that the frontend will reuse the same grants 285 * for all transactions, allowing the backend to map them with write 286 * access (even when it should be read-only). If the frontend hits the 287 * maximum number of allowed persistently mapped grants, it can fallback 288 * to non persistent mode. This will cause a performance degradation, 289 * since the the backend driver will still try to map those grants 290 * persistently. Since the persistent grants protocol is compatible with 291 * the previous protocol, a frontend driver can choose to work in 292 * persistent mode even when the backend doesn't support it. 293 * 294 * It is recommended that the frontend driver stores the persistently 295 * mapped grants in a LIFO queue, so a subset of all persistently mapped 296 * grants gets used commonly. This is done in case the backend driver 297 * decides to limit the maximum number of persistently mapped grants 298 * to a value less than RING_SIZE * BLKIF_MAX_SEGMENTS_PER_REQUEST. 299 * 300 *------------------------- Virtual Device Properties ------------------------- 301 * 302 * device-type 303 * Values: "disk", "cdrom", "floppy", etc. 304 * 305 * virtual-device 306 * Values: <UINT32> 307 * 308 * A value indicating the physical device to virtualize within the 309 * frontend's domain. (e.g. "The first ATA disk", "The third SCSI 310 * disk", etc.) 311 * 312 * See docs/misc/vbd-interface.txt for details on the format of this 313 * value. 314 * 315 * Notes 316 * ----- 317 * (1) Multi-page ring buffer scheme first developed in the Citrix XenServer 318 * PV drivers. 319 * (2) Multi-page ring buffer scheme first used in some RedHat distributions 320 * including a distribution deployed on certain nodes of the Amazon 321 * EC2 cluster. 322 * (3) Support for multi-page ring buffers was implemented independently, 323 * in slightly different forms, by both Citrix and RedHat/Amazon. 324 * For full interoperability, block front and backends should publish 325 * identical ring parameters, adjusted for unit differences, to the 326 * XenStore nodes used in both schemes. 327 * (4) Devices that support discard functionality may internally allocate space 328 * (discardable extents) in units that are larger than the exported logical 329 * block size. If the backing device has such discardable extents the 330 * backend should provide both discard-granularity and discard-alignment. 331 * Providing just one of the two may be considered an error by the frontend. 332 * Backends supporting discard should include discard-granularity and 333 * discard-alignment even if it supports discarding individual sectors. 334 * Frontends should assume discard-alignment == 0 and discard-granularity 335 * == sector size if these keys are missing. 336 * (5) The discard-alignment parameter allows a physical device to be 337 * partitioned into virtual devices that do not necessarily begin or 338 * end on a discardable extent boundary. 339 * (6) When there is only a single page allocated to the request ring, 340 * 'ring-ref' is used to communicate the grant reference for this 341 * page to the backend. When using a multi-page ring, the 'ring-ref' 342 * node is not created. Instead 'ring-ref0' - 'ring-refN' are used. 343 * (7) When using persistent grants data has to be copied from/to the page 344 * where the grant is currently mapped. The overhead of doing this copy 345 * however doesn't suppress the speed improvement of not having to unmap 346 * the grants. 347 * (8) The frontend driver has to allow the backend driver to map all grants 348 * with write access, even when they should be mapped read-only, since 349 * further requests may reuse these grants and require write permissions. 350 * (9) Linux implementation doesn't have a limit on the maximum number of 351 * grants that can be persistently mapped in the frontend driver, but 352 * due to the frontent driver implementation it should never be bigger 353 * than RING_SIZE * BLKIF_MAX_SEGMENTS_PER_REQUEST. 354 *(10) The discard-secure property may be present and will be set to 1 if the 355 * backing device supports secure discard. 356 */ 357 358 /* 359 * STATE DIAGRAMS 360 * 361 ***************************************************************************** 362 * Startup * 363 ***************************************************************************** 364 * 365 * Tool stack creates front and back nodes with state XenbusStateInitialising. 366 * 367 * Front Back 368 * ================================= ===================================== 369 * XenbusStateInitialising XenbusStateInitialising 370 * o Query virtual device o Query backend device identification 371 * properties. data. 372 * o Setup OS device instance. o Open and validate backend device. 373 * o Publish backend features and 374 * transport parameters. 375 * | 376 * | 377 * V 378 * XenbusStateInitWait 379 * 380 * o Query backend features and 381 * transport parameters. 382 * o Allocate and initialize the 383 * request ring. 384 * o Publish transport parameters 385 * that will be in effect during 386 * this connection. 387 * | 388 * | 389 * V 390 * XenbusStateInitialised 391 * 392 * o Query frontend transport parameters. 393 * o Connect to the request ring and 394 * event channel. 395 * o Publish backend device properties. 396 * | 397 * | 398 * V 399 * XenbusStateConnected 400 * 401 * o Query backend device properties. 402 * o Finalize OS virtual device 403 * instance. 404 * | 405 * | 406 * V 407 * XenbusStateConnected 408 * 409 * Note: Drivers that do not support any optional features, or the negotiation 410 * of transport parameters, can skip certain states in the state machine: 411 * 412 * o A frontend may transition to XenbusStateInitialised without 413 * waiting for the backend to enter XenbusStateInitWait. In this 414 * case, default transport parameters are in effect and any 415 * transport parameters published by the frontend must contain 416 * their default values. 417 * 418 * o A backend may transition to XenbusStateInitialised, bypassing 419 * XenbusStateInitWait, without waiting for the frontend to first 420 * enter the XenbusStateInitialised state. In this case, default 421 * transport parameters are in effect and any transport parameters 422 * published by the backend must contain their default values. 423 * 424 * Drivers that support optional features and/or transport parameter 425 * negotiation must tolerate these additional state transition paths. 426 * In general this means performing the work of any skipped state 427 * transition, if it has not already been performed, in addition to the 428 * work associated with entry into the current state. 429 */ 430 431 /* 432 * REQUEST CODES. 433 */ 434 #define BLKIF_OP_READ 0 435 #define BLKIF_OP_WRITE 1 436 /* 437 * All writes issued prior to a request with the BLKIF_OP_WRITE_BARRIER 438 * operation code ("barrier request") must be completed prior to the 439 * execution of the barrier request. All writes issued after the barrier 440 * request must not execute until after the completion of the barrier request. 441 * 442 * Optional. See "feature-barrier" XenBus node documentation above. 443 */ 444 #define BLKIF_OP_WRITE_BARRIER 2 445 /* 446 * Commit any uncommitted contents of the backing device's volatile cache 447 * to stable storage. 448 * 449 * Optional. See "feature-flush-cache" XenBus node documentation above. 450 */ 451 #define BLKIF_OP_FLUSH_DISKCACHE 3 452 /* 453 * Used in SLES sources for device specific command packet 454 * contained within the request. Reserved for that purpose. 455 */ 456 #define BLKIF_OP_RESERVED_1 4 457 /* 458 * Indicate to the backend device that a region of storage is no longer in 459 * use, and may be discarded at any time without impact to the client. If 460 * the BLKIF_DISCARD_SECURE flag is set on the request, all copies of the 461 * discarded region on the device must be rendered unrecoverable before the 462 * command returns. 463 * 464 * This operation is analogous to performing a trim (ATA) or unamp (SCSI), 465 * command on a native device. 466 * 467 * More information about trim/unmap operations can be found at: 468 * http://t13.org/Documents/UploadedDocuments/docs2008/ 469 * e07154r6-Data_Set_Management_Proposal_for_ATA-ACS2.doc 470 * http://www.seagate.com/staticfiles/support/disc/manuals/ 471 * Interface%20manuals/100293068c.pdf 472 * 473 * Optional. See "feature-discard", "discard-alignment", 474 * "discard-granularity", and "discard-secure" in the XenBus node 475 * documentation above. 476 */ 477 #define BLKIF_OP_DISCARD 5 478 479 /* 480 * Recognized if "feature-max-indirect-segments" in present in the backend 481 * xenbus info. The "feature-max-indirect-segments" node contains the maximum 482 * number of segments allowed by the backend per request. If the node is 483 * present, the frontend might use blkif_request_indirect structs in order to 484 * issue requests with more than BLKIF_MAX_SEGMENTS_PER_REQUEST (11). The 485 * maximum number of indirect segments is fixed by the backend, but the 486 * frontend can issue requests with any number of indirect segments as long as 487 * it's less than the number provided by the backend. The indirect_grefs field 488 * in blkif_request_indirect should be filled by the frontend with the 489 * grant references of the pages that are holding the indirect segments. 490 * These pages are filled with an array of blkif_request_segment that hold the 491 * information about the segments. The number of indirect pages to use is 492 * determined by the number of segments an indirect request contains. Every 493 * indirect page can contain a maximum of 494 * (PAGE_SIZE / sizeof(struct blkif_request_segment)) segments, so to 495 * calculate the number of indirect pages to use we have to do 496 * ceil(indirect_segments / (PAGE_SIZE / sizeof(struct blkif_request_segment))). 497 * 498 * If a backend does not recognize BLKIF_OP_INDIRECT, it should *not* 499 * create the "feature-max-indirect-segments" node! 500 */ 501 #define BLKIF_OP_INDIRECT 6 502 503 /* 504 * Maximum scatter/gather segments per request. 505 * This is carefully chosen so that sizeof(blkif_ring_t) <= PAGE_SIZE. 506 * NB. This could be 12 if the ring indexes weren't stored in the same page. 507 */ 508 #define BLKIF_MAX_SEGMENTS_PER_REQUEST 11 509 510 /* 511 * Maximum number of indirect pages to use per request. 512 */ 513 #define BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST 8 514 515 /* 516 * NB. first_sect and last_sect in blkif_request_segment, as well as 517 * sector_number in blkif_request, are always expressed in 512-byte units. 518 * However they must be properly aligned to the real sector size of the 519 * physical disk, which is reported in the "physical-sector-size" node in 520 * the backend xenbus info. Also the xenbus "sectors" node is expressed in 521 * 512-byte units. 522 */ 523 struct blkif_request_segment { 524 grant_ref_t gref; /* reference to I/O buffer frame */ 525 /* @first_sect: first sector in frame to transfer (inclusive). */ 526 /* @last_sect: last sector in frame to transfer (inclusive). */ 527 UINT8 first_sect, last_sect; 528 }; 529 530 /* 531 * Starting ring element for any I/O request. 532 */ 533 #if defined(MDE_CPU_IA32) 534 // 535 // pack(4) is necessary when these structs are compiled for Ia32. 536 // Without it, the struct will have a different alignment than the one 537 // a backend expect for a 32bit guest. 538 // 539 #pragma pack(4) 540 #endif 541 struct blkif_request { 542 UINT8 operation; /* BLKIF_OP_??? */ 543 UINT8 nr_segments; /* number of segments */ 544 blkif_vdev_t handle; /* only for read/write requests */ 545 UINT64 id; /* private guest value, echoed in resp */ 546 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ 547 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; 548 }; 549 typedef struct blkif_request blkif_request_t; 550 551 /* 552 * Cast to this structure when blkif_request.operation == BLKIF_OP_DISCARD 553 * sizeof(struct blkif_request_discard) <= sizeof(struct blkif_request) 554 */ 555 struct blkif_request_discard { 556 UINT8 operation; /* BLKIF_OP_DISCARD */ 557 UINT8 flag; /* BLKIF_DISCARD_SECURE or zero */ 558 #define BLKIF_DISCARD_SECURE (1<<0) /* ignored if discard-secure=0 */ 559 blkif_vdev_t handle; /* same as for read/write requests */ 560 UINT64 id; /* private guest value, echoed in resp */ 561 blkif_sector_t sector_number;/* start sector idx on disk */ 562 UINT64 nr_sectors; /* number of contiguous sectors to discard*/ 563 }; 564 typedef struct blkif_request_discard blkif_request_discard_t; 565 566 struct blkif_request_indirect { 567 UINT8 operation; /* BLKIF_OP_INDIRECT */ 568 UINT8 indirect_op; /* BLKIF_OP_{READ/WRITE} */ 569 UINT16 nr_segments; /* number of segments */ 570 UINT64 id; /* private guest value, echoed in resp */ 571 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ 572 blkif_vdev_t handle; /* same as for read/write requests */ 573 grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST]; 574 #ifdef MDE_CPU_IA32 575 UINT64 pad; /* Make it 64 byte aligned on i386 */ 576 #endif 577 }; 578 typedef struct blkif_request_indirect blkif_request_indirect_t; 579 580 struct blkif_response { 581 UINT64 id; /* copied from request */ 582 UINT8 operation; /* copied from request */ 583 INT16 status; /* BLKIF_RSP_??? */ 584 }; 585 typedef struct blkif_response blkif_response_t; 586 #if defined(MDE_CPU_IA32) 587 #pragma pack() 588 #endif 589 590 /* 591 * STATUS RETURN CODES. 592 */ 593 /* Operation not supported (only happens on barrier writes). */ 594 #define BLKIF_RSP_EOPNOTSUPP -2 595 /* Operation failed for some unspecified reason (-EIO). */ 596 #define BLKIF_RSP_ERROR -1 597 /* Operation completed successfully. */ 598 #define BLKIF_RSP_OKAY 0 599 600 /* 601 * Generate blkif ring structures and types. 602 */ 603 DEFINE_RING_TYPES(blkif, struct blkif_request, struct blkif_response); 604 605 #define VDISK_CDROM 0x1 606 #define VDISK_REMOVABLE 0x2 607 #define VDISK_READONLY 0x4 608 609 #endif /* __XEN_PUBLIC_IO_BLKIF_H__ */ 610 611 /* 612 * Local variables: 613 * mode: C 614 * c-file-style: "BSD" 615 * c-basic-offset: 4 616 * tab-width: 4 617 * indent-tabs-mode: nil 618 * End: 619 */ 620
