extents.c 25.8 KB
Newer Older
F
Fred Isaman 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
/*
 *  linux/fs/nfs/blocklayout/blocklayout.h
 *
 *  Module for the NFSv4.1 pNFS block layout driver.
 *
 *  Copyright (c) 2006 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Andy Adamson <andros@citi.umich.edu>
 *  Fred Isaman <iisaman@umich.edu>
 *
 * permission is granted to use, copy, create derivative works and
 * redistribute this software and such derivative works for any purpose,
 * so long as the name of the university of michigan is not used in
 * any advertising or publicity pertaining to the use or distribution
 * of this software without specific, written prior authorization.  if
 * the above copyright notice or any other identification of the
 * university of michigan is included in any copy of any portion of
 * this software, then the disclaimer below must also be included.
 *
 * this software is provided as is, without representation from the
 * university of michigan as to its fitness for any purpose, and without
 * warranty by the university of michigan of any kind, either express
 * or implied, including without limitation the implied warranties of
 * merchantability and fitness for a particular purpose.  the regents
 * of the university of michigan shall not be liable for any damages,
 * including special, indirect, incidental, or consequential damages,
 * with respect to any claim arising out or in connection with the use
 * of the software, even if it has been or is hereafter advised of the
 * possibility of such damages.
 */

#include "blocklayout.h"
#define NFSDBG_FACILITY         NFSDBG_PNFS_LD

36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219
/* Bit numbers */
#define EXTENT_INITIALIZED 0
#define EXTENT_WRITTEN     1
#define EXTENT_IN_COMMIT   2
#define INTERNAL_EXISTS    MY_MAX_TAGS
#define INTERNAL_MASK      ((1 << INTERNAL_EXISTS) - 1)

/* Returns largest t<=s s.t. t%base==0 */
static inline sector_t normalize(sector_t s, int base)
{
	sector_t tmp = s; /* Since do_div modifies its argument */
	return s - do_div(tmp, base);
}

static inline sector_t normalize_up(sector_t s, int base)
{
	return normalize(s + base - 1, base);
}

/* Complete stub using list while determine API wanted */

/* Returns tags, or negative */
static int32_t _find_entry(struct my_tree *tree, u64 s)
{
	struct pnfs_inval_tracking *pos;

	dprintk("%s(%llu) enter\n", __func__, s);
	list_for_each_entry_reverse(pos, &tree->mtt_stub, it_link) {
		if (pos->it_sector > s)
			continue;
		else if (pos->it_sector == s)
			return pos->it_tags & INTERNAL_MASK;
		else
			break;
	}
	return -ENOENT;
}

static inline
int _has_tag(struct my_tree *tree, u64 s, int32_t tag)
{
	int32_t tags;

	dprintk("%s(%llu, %i) enter\n", __func__, s, tag);
	s = normalize(s, tree->mtt_step_size);
	tags = _find_entry(tree, s);
	if ((tags < 0) || !(tags & (1 << tag)))
		return 0;
	else
		return 1;
}

/* Creates entry with tag, or if entry already exists, unions tag to it.
 * If storage is not NULL, newly created entry will use it.
 * Returns number of entries added, or negative on error.
 */
static int _add_entry(struct my_tree *tree, u64 s, int32_t tag,
		      struct pnfs_inval_tracking *storage)
{
	int found = 0;
	struct pnfs_inval_tracking *pos;

	dprintk("%s(%llu, %i, %p) enter\n", __func__, s, tag, storage);
	list_for_each_entry_reverse(pos, &tree->mtt_stub, it_link) {
		if (pos->it_sector > s)
			continue;
		else if (pos->it_sector == s) {
			found = 1;
			break;
		} else
			break;
	}
	if (found) {
		pos->it_tags |= (1 << tag);
		return 0;
	} else {
		struct pnfs_inval_tracking *new;
		if (storage)
			new = storage;
		else {
			new = kmalloc(sizeof(*new), GFP_NOFS);
			if (!new)
				return -ENOMEM;
		}
		new->it_sector = s;
		new->it_tags = (1 << tag);
		list_add(&new->it_link, &pos->it_link);
		return 1;
	}
}

/* XXXX Really want option to not create */
/* Over range, unions tag with existing entries, else creates entry with tag */
static int _set_range(struct my_tree *tree, int32_t tag, u64 s, u64 length)
{
	u64 i;

	dprintk("%s(%i, %llu, %llu) enter\n", __func__, tag, s, length);
	for (i = normalize(s, tree->mtt_step_size); i < s + length;
	     i += tree->mtt_step_size)
		if (_add_entry(tree, i, tag, NULL))
			return -ENOMEM;
	return 0;
}

/* Ensure that future operations on given range of tree will not malloc */
static int _preload_range(struct my_tree *tree, u64 offset, u64 length)
{
	u64 start, end, s;
	int count, i, used = 0, status = -ENOMEM;
	struct pnfs_inval_tracking **storage;

	dprintk("%s(%llu, %llu) enter\n", __func__, offset, length);
	start = normalize(offset, tree->mtt_step_size);
	end = normalize_up(offset + length, tree->mtt_step_size);
	count = (int)(end - start) / (int)tree->mtt_step_size;

	/* Pre-malloc what memory we might need */
	storage = kmalloc(sizeof(*storage) * count, GFP_NOFS);
	if (!storage)
		return -ENOMEM;
	for (i = 0; i < count; i++) {
		storage[i] = kmalloc(sizeof(struct pnfs_inval_tracking),
				     GFP_NOFS);
		if (!storage[i])
			goto out_cleanup;
	}

	/* Now need lock - HOW??? */

	for (s = start; s < end; s += tree->mtt_step_size)
		used += _add_entry(tree, s, INTERNAL_EXISTS, storage[used]);

	/* Unlock - HOW??? */
	status = 0;

 out_cleanup:
	for (i = used; i < count; i++) {
		if (!storage[i])
			break;
		kfree(storage[i]);
	}
	kfree(storage);
	return status;
}

static void set_needs_init(sector_t *array, sector_t offset)
{
	sector_t *p = array;

	dprintk("%s enter\n", __func__);
	if (!p)
		return;
	while (*p < offset)
		p++;
	if (*p == offset)
		return;
	else if (*p == ~0) {
		*p++ = offset;
		*p = ~0;
		return;
	} else {
		sector_t *save = p;
		dprintk("%s Adding %llu\n", __func__, (u64)offset);
		while (*p != ~0)
			p++;
		p++;
		memmove(save + 1, save, (char *)p - (char *)save);
		*save = offset;
		return;
	}
}

/* We are relying on page lock to serialize this */
int bl_is_sector_init(struct pnfs_inval_markings *marks, sector_t isect)
{
	int rv;

	spin_lock(&marks->im_lock);
	rv = _has_tag(&marks->im_tree, isect, EXTENT_INITIALIZED);
	spin_unlock(&marks->im_lock);
	return rv;
}

220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261
/* Assume start, end already sector aligned */
static int
_range_has_tag(struct my_tree *tree, u64 start, u64 end, int32_t tag)
{
	struct pnfs_inval_tracking *pos;
	u64 expect = 0;

	dprintk("%s(%llu, %llu, %i) enter\n", __func__, start, end, tag);
	list_for_each_entry_reverse(pos, &tree->mtt_stub, it_link) {
		if (pos->it_sector >= end)
			continue;
		if (!expect) {
			if ((pos->it_sector == end - tree->mtt_step_size) &&
			    (pos->it_tags & (1 << tag))) {
				expect = pos->it_sector - tree->mtt_step_size;
				if (pos->it_sector < tree->mtt_step_size || expect < start)
					return 1;
				continue;
			} else {
				return 0;
			}
		}
		if (pos->it_sector != expect || !(pos->it_tags & (1 << tag)))
			return 0;
		expect -= tree->mtt_step_size;
		if (expect < start)
			return 1;
	}
	return 0;
}

static int is_range_written(struct pnfs_inval_markings *marks,
			    sector_t start, sector_t end)
{
	int rv;

	spin_lock(&marks->im_lock);
	rv = _range_has_tag(&marks->im_tree, start, end, EXTENT_WRITTEN);
	spin_unlock(&marks->im_lock);
	return rv;
}

262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330
/* Marks sectors in [offest, offset_length) as having been initialized.
 * All lengths are step-aligned, where step is min(pagesize, blocksize).
 * Notes where partial block is initialized, and helps prepare it for
 * complete initialization later.
 */
/* Currently assumes offset is page-aligned */
int bl_mark_sectors_init(struct pnfs_inval_markings *marks,
			     sector_t offset, sector_t length,
			     sector_t **pages)
{
	sector_t s, start, end;
	sector_t *array = NULL; /* Pages to mark */

	dprintk("%s(offset=%llu,len=%llu) enter\n",
		__func__, (u64)offset, (u64)length);
	s = max((sector_t) 3,
		2 * (marks->im_block_size / (PAGE_CACHE_SECTORS)));
	dprintk("%s set max=%llu\n", __func__, (u64)s);
	if (pages) {
		array = kmalloc(s * sizeof(sector_t), GFP_NOFS);
		if (!array)
			goto outerr;
		array[0] = ~0;
	}

	start = normalize(offset, marks->im_block_size);
	end = normalize_up(offset + length, marks->im_block_size);
	if (_preload_range(&marks->im_tree, start, end - start))
		goto outerr;

	spin_lock(&marks->im_lock);

	for (s = normalize_up(start, PAGE_CACHE_SECTORS);
	     s < offset; s += PAGE_CACHE_SECTORS) {
		dprintk("%s pre-area pages\n", __func__);
		/* Portion of used block is not initialized */
		if (!_has_tag(&marks->im_tree, s, EXTENT_INITIALIZED))
			set_needs_init(array, s);
	}
	if (_set_range(&marks->im_tree, EXTENT_INITIALIZED, offset, length))
		goto out_unlock;
	for (s = normalize_up(offset + length, PAGE_CACHE_SECTORS);
	     s < end; s += PAGE_CACHE_SECTORS) {
		dprintk("%s post-area pages\n", __func__);
		if (!_has_tag(&marks->im_tree, s, EXTENT_INITIALIZED))
			set_needs_init(array, s);
	}

	spin_unlock(&marks->im_lock);

	if (pages) {
		if (array[0] == ~0) {
			kfree(array);
			*pages = NULL;
		} else
			*pages = array;
	}
	return 0;

 out_unlock:
	spin_unlock(&marks->im_lock);
 outerr:
	if (pages) {
		kfree(array);
		*pages = NULL;
	}
	return -ENOMEM;
}

F
Fred Isaman 已提交
331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373
/* Marks sectors in [offest, offset+length) as having been written to disk.
 * All lengths should be block aligned.
 */
static int mark_written_sectors(struct pnfs_inval_markings *marks,
				sector_t offset, sector_t length)
{
	int status;

	dprintk("%s(offset=%llu,len=%llu) enter\n", __func__,
		(u64)offset, (u64)length);
	spin_lock(&marks->im_lock);
	status = _set_range(&marks->im_tree, EXTENT_WRITTEN, offset, length);
	spin_unlock(&marks->im_lock);
	return status;
}

static void print_short_extent(struct pnfs_block_short_extent *be)
{
	dprintk("PRINT SHORT EXTENT extent %p\n", be);
	if (be) {
		dprintk("        be_f_offset %llu\n", (u64)be->bse_f_offset);
		dprintk("        be_length   %llu\n", (u64)be->bse_length);
	}
}

static void print_clist(struct list_head *list, unsigned int count)
{
	struct pnfs_block_short_extent *be;
	unsigned int i = 0;

	ifdebug(FACILITY) {
		printk(KERN_DEBUG "****************\n");
		printk(KERN_DEBUG "Extent list looks like:\n");
		list_for_each_entry(be, list, bse_node) {
			i++;
			print_short_extent(be);
		}
		if (i != count)
			printk(KERN_DEBUG "\n\nExpected %u entries\n\n\n", count);
		printk(KERN_DEBUG "****************\n");
	}
}

F
Fred Isaman 已提交
374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440
/* Note: In theory, we should do more checking that devid's match between
 * old and new, but if they don't, the lists are too corrupt to salvage anyway.
 */
/* Note this is very similar to bl_add_merge_extent */
static void add_to_commitlist(struct pnfs_block_layout *bl,
			      struct pnfs_block_short_extent *new)
{
	struct list_head *clist = &bl->bl_commit;
	struct pnfs_block_short_extent *old, *save;
	sector_t end = new->bse_f_offset + new->bse_length;

	dprintk("%s enter\n", __func__);
	print_short_extent(new);
	print_clist(clist, bl->bl_count);
	bl->bl_count++;
	/* Scan for proper place to insert, extending new to the left
	 * as much as possible.
	 */
	list_for_each_entry_safe(old, save, clist, bse_node) {
		if (new->bse_f_offset < old->bse_f_offset)
			break;
		if (end <= old->bse_f_offset + old->bse_length) {
			/* Range is already in list */
			bl->bl_count--;
			kfree(new);
			return;
		} else if (new->bse_f_offset <=
				old->bse_f_offset + old->bse_length) {
			/* new overlaps or abuts existing be */
			if (new->bse_mdev == old->bse_mdev) {
				/* extend new to fully replace old */
				new->bse_length += new->bse_f_offset -
						old->bse_f_offset;
				new->bse_f_offset = old->bse_f_offset;
				list_del(&old->bse_node);
				bl->bl_count--;
				kfree(old);
			}
		}
	}
	/* Note that if we never hit the above break, old will not point to a
	 * valid extent.  However, in that case &old->bse_node==list.
	 */
	list_add_tail(&new->bse_node, &old->bse_node);
	/* Scan forward for overlaps.  If we find any, extend new and
	 * remove the overlapped extent.
	 */
	old = list_prepare_entry(new, clist, bse_node);
	list_for_each_entry_safe_continue(old, save, clist, bse_node) {
		if (end < old->bse_f_offset)
			break;
		/* new overlaps or abuts old */
		if (new->bse_mdev == old->bse_mdev) {
			if (end < old->bse_f_offset + old->bse_length) {
				/* extend new to fully cover old */
				end = old->bse_f_offset + old->bse_length;
				new->bse_length = end - new->bse_f_offset;
			}
			list_del(&old->bse_node);
			bl->bl_count--;
			kfree(old);
		}
	}
	dprintk("%s: after merging\n", __func__);
	print_clist(clist, bl->bl_count);
}

441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493
/* Note the range described by offset, length is guaranteed to be contained
 * within be.
 */
int bl_mark_for_commit(struct pnfs_block_extent *be,
		    sector_t offset, sector_t length)
{
	sector_t new_end, end = offset + length;
	struct pnfs_block_short_extent *new;
	struct pnfs_block_layout *bl = container_of(be->be_inval,
						    struct pnfs_block_layout,
						    bl_inval);

	new = kmalloc(sizeof(*new), GFP_NOFS);
	if (!new)
		return -ENOMEM;

	mark_written_sectors(be->be_inval, offset, length);
	/* We want to add the range to commit list, but it must be
	 * block-normalized, and verified that the normalized range has
	 * been entirely written to disk.
	 */
	new->bse_f_offset = offset;
	offset = normalize(offset, bl->bl_blocksize);
	if (offset < new->bse_f_offset) {
		if (is_range_written(be->be_inval, offset, new->bse_f_offset))
			new->bse_f_offset = offset;
		else
			new->bse_f_offset = offset + bl->bl_blocksize;
	}
	new_end = normalize_up(end, bl->bl_blocksize);
	if (end < new_end) {
		if (is_range_written(be->be_inval, end, new_end))
			end = new_end;
		else
			end = new_end - bl->bl_blocksize;
	}
	if (end <= new->bse_f_offset) {
		kfree(new);
		return 0;
	}
	new->bse_length = end - new->bse_f_offset;
	new->bse_devid = be->be_devid;
	new->bse_mdev = be->be_mdev;

	spin_lock(&bl->bl_ext_lock);
	/* new will be freed, either by add_to_commitlist if it decides not
	 * to use it, or after LAYOUTCOMMIT uses it in the commitlist.
	 */
	add_to_commitlist(bl, new);
	spin_unlock(&bl->bl_ext_lock);
	return 0;
}

F
Fred Isaman 已提交
494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547
static void print_bl_extent(struct pnfs_block_extent *be)
{
	dprintk("PRINT EXTENT extent %p\n", be);
	if (be) {
		dprintk("        be_f_offset %llu\n", (u64)be->be_f_offset);
		dprintk("        be_length   %llu\n", (u64)be->be_length);
		dprintk("        be_v_offset %llu\n", (u64)be->be_v_offset);
		dprintk("        be_state    %d\n", be->be_state);
	}
}

static void
destroy_extent(struct kref *kref)
{
	struct pnfs_block_extent *be;

	be = container_of(kref, struct pnfs_block_extent, be_refcnt);
	dprintk("%s be=%p\n", __func__, be);
	kfree(be);
}

void
bl_put_extent(struct pnfs_block_extent *be)
{
	if (be) {
		dprintk("%s enter %p (%i)\n", __func__, be,
			atomic_read(&be->be_refcnt.refcount));
		kref_put(&be->be_refcnt, destroy_extent);
	}
}

struct pnfs_block_extent *bl_alloc_extent(void)
{
	struct pnfs_block_extent *be;

	be = kmalloc(sizeof(struct pnfs_block_extent), GFP_NOFS);
	if (!be)
		return NULL;
	INIT_LIST_HEAD(&be->be_node);
	kref_init(&be->be_refcnt);
	be->be_inval = NULL;
	return be;
}

static void print_elist(struct list_head *list)
{
	struct pnfs_block_extent *be;
	dprintk("****************\n");
	dprintk("Extent list looks like:\n");
	list_for_each_entry(be, list, be_node) {
		print_bl_extent(be);
	}
	dprintk("****************\n");
}
F
Fred Isaman 已提交
548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585

static inline int
extents_consistent(struct pnfs_block_extent *old, struct pnfs_block_extent *new)
{
	/* Note this assumes new->be_f_offset >= old->be_f_offset */
	return (new->be_state == old->be_state) &&
		((new->be_state == PNFS_BLOCK_NONE_DATA) ||
		 ((new->be_v_offset - old->be_v_offset ==
		   new->be_f_offset - old->be_f_offset) &&
		  new->be_mdev == old->be_mdev));
}

/* Adds new to appropriate list in bl, modifying new and removing existing
 * extents as appropriate to deal with overlaps.
 *
 * See bl_find_get_extent for list constraints.
 *
 * Refcount on new is already set.  If end up not using it, or error out,
 * need to put the reference.
 *
 * bl->bl_ext_lock is held by caller.
 */
int
bl_add_merge_extent(struct pnfs_block_layout *bl,
		     struct pnfs_block_extent *new)
{
	struct pnfs_block_extent *be, *tmp;
	sector_t end = new->be_f_offset + new->be_length;
	struct list_head *list;

	dprintk("%s enter with be=%p\n", __func__, new);
	print_bl_extent(new);
	list = &bl->bl_extents[bl_choose_list(new->be_state)];
	print_elist(list);

	/* Scan for proper place to insert, extending new to the left
	 * as much as possible.
	 */
F
Fred Isaman 已提交
586 587
	list_for_each_entry_safe_reverse(be, tmp, list, be_node) {
		if (new->be_f_offset >= be->be_f_offset + be->be_length)
F
Fred Isaman 已提交
588
			break;
F
Fred Isaman 已提交
589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617
		if (new->be_f_offset >= be->be_f_offset) {
			if (end <= be->be_f_offset + be->be_length) {
				/* new is a subset of existing be*/
				if (extents_consistent(be, new)) {
					dprintk("%s: new is subset, ignoring\n",
						__func__);
					bl_put_extent(new);
					return 0;
				} else {
					goto out_err;
				}
			} else {
				/* |<--   be   -->|
				 *          |<--   new   -->| */
				if (extents_consistent(be, new)) {
					/* extend new to fully replace be */
					new->be_length += new->be_f_offset -
						be->be_f_offset;
					new->be_f_offset = be->be_f_offset;
					new->be_v_offset = be->be_v_offset;
					dprintk("%s: removing %p\n", __func__, be);
					list_del(&be->be_node);
					bl_put_extent(be);
				} else {
					goto out_err;
				}
			}
		} else if (end >= be->be_f_offset + be->be_length) {
			/* new extent overlap existing be */
F
Fred Isaman 已提交
618
			if (extents_consistent(be, new)) {
F
Fred Isaman 已提交
619 620 621 622 623
				/* extend new to fully replace be */
				dprintk("%s: removing %p\n", __func__, be);
				list_del(&be->be_node);
				bl_put_extent(be);
			} else {
F
Fred Isaman 已提交
624
				goto out_err;
F
Fred Isaman 已提交
625 626 627 628 629
			}
		} else if (end > be->be_f_offset) {
			/*           |<--   be   -->|
			 *|<--   new   -->| */
			if (extents_consistent(new, be)) {
F
Fred Isaman 已提交
630
				/* extend new to fully replace be */
F
Fred Isaman 已提交
631 632
				new->be_length += be->be_f_offset + be->be_length -
					new->be_f_offset - new->be_length;
F
Fred Isaman 已提交
633 634 635
				dprintk("%s: removing %p\n", __func__, be);
				list_del(&be->be_node);
				bl_put_extent(be);
F
Fred Isaman 已提交
636
			} else {
F
Fred Isaman 已提交
637
				goto out_err;
F
Fred Isaman 已提交
638
			}
F
Fred Isaman 已提交
639 640 641 642 643
		}
	}
	/* Note that if we never hit the above break, be will not point to a
	 * valid extent.  However, in that case &be->be_node==list.
	 */
F
Fred Isaman 已提交
644
	list_add(&new->be_node, &be->be_node);
F
Fred Isaman 已提交
645 646 647 648 649 650 651 652 653 654 655
	dprintk("%s: inserting new\n", __func__);
	print_elist(list);
	/* FIXME - The per-list consistency checks have all been done,
	 * should now check cross-list consistency.
	 */
	return 0;

 out_err:
	bl_put_extent(new);
	return -EIO;
}
F
Fred Isaman 已提交
656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702

/* Returns extent, or NULL.  If a second READ extent exists, it is returned
 * in cow_read, if given.
 *
 * The extents are kept in two seperate ordered lists, one for READ and NONE,
 * one for READWRITE and INVALID.  Within each list, we assume:
 * 1. Extents are ordered by file offset.
 * 2. For any given isect, there is at most one extents that matches.
 */
struct pnfs_block_extent *
bl_find_get_extent(struct pnfs_block_layout *bl, sector_t isect,
	    struct pnfs_block_extent **cow_read)
{
	struct pnfs_block_extent *be, *cow, *ret;
	int i;

	dprintk("%s enter with isect %llu\n", __func__, (u64)isect);
	cow = ret = NULL;
	spin_lock(&bl->bl_ext_lock);
	for (i = 0; i < EXTENT_LISTS; i++) {
		list_for_each_entry_reverse(be, &bl->bl_extents[i], be_node) {
			if (isect >= be->be_f_offset + be->be_length)
				break;
			if (isect >= be->be_f_offset) {
				/* We have found an extent */
				dprintk("%s Get %p (%i)\n", __func__, be,
					atomic_read(&be->be_refcnt.refcount));
				kref_get(&be->be_refcnt);
				if (!ret)
					ret = be;
				else if (be->be_state != PNFS_BLOCK_READ_DATA)
					bl_put_extent(be);
				else
					cow = be;
				break;
			}
		}
		if (ret &&
		    (!cow_read || ret->be_state != PNFS_BLOCK_INVALID_DATA))
			break;
	}
	spin_unlock(&bl->bl_ext_lock);
	if (cow_read)
		*cow_read = cow;
	print_bl_extent(ret);
	return ret;
}
F
Fred Isaman 已提交
703

F
Fred Isaman 已提交
704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731
/* Similar to bl_find_get_extent, but called with lock held, and ignores cow */
static struct pnfs_block_extent *
bl_find_get_extent_locked(struct pnfs_block_layout *bl, sector_t isect)
{
	struct pnfs_block_extent *be, *ret = NULL;
	int i;

	dprintk("%s enter with isect %llu\n", __func__, (u64)isect);
	for (i = 0; i < EXTENT_LISTS; i++) {
		if (ret)
			break;
		list_for_each_entry_reverse(be, &bl->bl_extents[i], be_node) {
			if (isect >= be->be_f_offset + be->be_length)
				break;
			if (isect >= be->be_f_offset) {
				/* We have found an extent */
				dprintk("%s Get %p (%i)\n", __func__, be,
					atomic_read(&be->be_refcnt.refcount));
				kref_get(&be->be_refcnt);
				ret = be;
				break;
			}
		}
	}
	print_bl_extent(ret);
	return ret;
}

F
Fred Isaman 已提交
732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774
int
encode_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
			       struct xdr_stream *xdr,
			       const struct nfs4_layoutcommit_args *arg)
{
	struct pnfs_block_short_extent *lce, *save;
	unsigned int count = 0;
	__be32 *p, *xdr_start;

	dprintk("%s enter\n", __func__);
	/* BUG - creation of bl_commit is buggy - need to wait for
	 * entire block to be marked WRITTEN before it can be added.
	 */
	spin_lock(&bl->bl_ext_lock);
	/* Want to adjust for possible truncate */
	/* We now want to adjust argument range */

	/* XDR encode the ranges found */
	xdr_start = xdr_reserve_space(xdr, 8);
	if (!xdr_start)
		goto out;
	list_for_each_entry_safe(lce, save, &bl->bl_commit, bse_node) {
		p = xdr_reserve_space(xdr, 7 * 4 + sizeof(lce->bse_devid.data));
		if (!p)
			break;
		p = xdr_encode_opaque_fixed(p, lce->bse_devid.data, NFS4_DEVICEID4_SIZE);
		p = xdr_encode_hyper(p, lce->bse_f_offset << SECTOR_SHIFT);
		p = xdr_encode_hyper(p, lce->bse_length << SECTOR_SHIFT);
		p = xdr_encode_hyper(p, 0LL);
		*p++ = cpu_to_be32(PNFS_BLOCK_READWRITE_DATA);
		list_del(&lce->bse_node);
		list_add_tail(&lce->bse_node, &bl->bl_committing);
		bl->bl_count--;
		count++;
	}
	xdr_start[0] = cpu_to_be32((xdr->p - xdr_start - 1) * 4);
	xdr_start[1] = cpu_to_be32(count);
out:
	spin_unlock(&bl->bl_ext_lock);
	dprintk("%s found %i ranges\n", __func__, count);
	return 0;
}

F
Fred Isaman 已提交
775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820
/* Helper function to set_to_rw that initialize a new extent */
static void
_prep_new_extent(struct pnfs_block_extent *new,
		 struct pnfs_block_extent *orig,
		 sector_t offset, sector_t length, int state)
{
	kref_init(&new->be_refcnt);
	/* don't need to INIT_LIST_HEAD(&new->be_node) */
	memcpy(&new->be_devid, &orig->be_devid, sizeof(struct nfs4_deviceid));
	new->be_mdev = orig->be_mdev;
	new->be_f_offset = offset;
	new->be_length = length;
	new->be_v_offset = orig->be_v_offset - orig->be_f_offset + offset;
	new->be_state = state;
	new->be_inval = orig->be_inval;
}

/* Tries to merge be with extent in front of it in list.
 * Frees storage if not used.
 */
static struct pnfs_block_extent *
_front_merge(struct pnfs_block_extent *be, struct list_head *head,
	     struct pnfs_block_extent *storage)
{
	struct pnfs_block_extent *prev;

	if (!storage)
		goto no_merge;
	if (&be->be_node == head || be->be_node.prev == head)
		goto no_merge;
	prev = list_entry(be->be_node.prev, struct pnfs_block_extent, be_node);
	if ((prev->be_f_offset + prev->be_length != be->be_f_offset) ||
	    !extents_consistent(prev, be))
		goto no_merge;
	_prep_new_extent(storage, prev, prev->be_f_offset,
			 prev->be_length + be->be_length, prev->be_state);
	list_replace(&prev->be_node, &storage->be_node);
	bl_put_extent(prev);
	list_del(&be->be_node);
	bl_put_extent(be);
	return storage;

 no_merge:
	kfree(storage);
	return be;
}
F
Fred Isaman 已提交
821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935

static u64
set_to_rw(struct pnfs_block_layout *bl, u64 offset, u64 length)
{
	u64 rv = offset + length;
	struct pnfs_block_extent *be, *e1, *e2, *e3, *new, *old;
	struct pnfs_block_extent *children[3];
	struct pnfs_block_extent *merge1 = NULL, *merge2 = NULL;
	int i = 0, j;

	dprintk("%s(%llu, %llu)\n", __func__, offset, length);
	/* Create storage for up to three new extents e1, e2, e3 */
	e1 = kmalloc(sizeof(*e1), GFP_ATOMIC);
	e2 = kmalloc(sizeof(*e2), GFP_ATOMIC);
	e3 = kmalloc(sizeof(*e3), GFP_ATOMIC);
	/* BUG - we are ignoring any failure */
	if (!e1 || !e2 || !e3)
		goto out_nosplit;

	spin_lock(&bl->bl_ext_lock);
	be = bl_find_get_extent_locked(bl, offset);
	rv = be->be_f_offset + be->be_length;
	if (be->be_state != PNFS_BLOCK_INVALID_DATA) {
		spin_unlock(&bl->bl_ext_lock);
		goto out_nosplit;
	}
	/* Add e* to children, bumping e*'s krefs */
	if (be->be_f_offset != offset) {
		_prep_new_extent(e1, be, be->be_f_offset,
				 offset - be->be_f_offset,
				 PNFS_BLOCK_INVALID_DATA);
		children[i++] = e1;
		print_bl_extent(e1);
	} else
		merge1 = e1;
	_prep_new_extent(e2, be, offset,
			 min(length, be->be_f_offset + be->be_length - offset),
			 PNFS_BLOCK_READWRITE_DATA);
	children[i++] = e2;
	print_bl_extent(e2);
	if (offset + length < be->be_f_offset + be->be_length) {
		_prep_new_extent(e3, be, e2->be_f_offset + e2->be_length,
				 be->be_f_offset + be->be_length -
				 offset - length,
				 PNFS_BLOCK_INVALID_DATA);
		children[i++] = e3;
		print_bl_extent(e3);
	} else
		merge2 = e3;

	/* Remove be from list, and insert the e* */
	/* We don't get refs on e*, since this list is the base reference
	 * set when init'ed.
	 */
	if (i < 3)
		children[i] = NULL;
	new = children[0];
	list_replace(&be->be_node, &new->be_node);
	bl_put_extent(be);
	new = _front_merge(new, &bl->bl_extents[RW_EXTENT], merge1);
	for (j = 1; j < i; j++) {
		old = new;
		new = children[j];
		list_add(&new->be_node, &old->be_node);
	}
	if (merge2) {
		/* This is a HACK, should just create a _back_merge function */
		new = list_entry(new->be_node.next,
				 struct pnfs_block_extent, be_node);
		new = _front_merge(new, &bl->bl_extents[RW_EXTENT], merge2);
	}
	spin_unlock(&bl->bl_ext_lock);

	/* Since we removed the base reference above, be is now scheduled for
	 * destruction.
	 */
	bl_put_extent(be);
	dprintk("%s returns %llu after split\n", __func__, rv);
	return rv;

 out_nosplit:
	kfree(e1);
	kfree(e2);
	kfree(e3);
	dprintk("%s returns %llu without splitting\n", __func__, rv);
	return rv;
}

void
clean_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
			      const struct nfs4_layoutcommit_args *arg,
			      int status)
{
	struct pnfs_block_short_extent *lce, *save;

	dprintk("%s status %d\n", __func__, status);
	list_for_each_entry_safe(lce, save, &bl->bl_committing, bse_node) {
		if (likely(!status)) {
			u64 offset = lce->bse_f_offset;
			u64 end = offset + lce->bse_length;

			do {
				offset = set_to_rw(bl, offset, end - offset);
			} while (offset < end);
			list_del(&lce->bse_node);

			kfree(lce);
		} else {
			list_del(&lce->bse_node);
			spin_lock(&bl->bl_ext_lock);
			add_to_commitlist(bl, lce);
			spin_unlock(&bl->bl_ext_lock);
		}
	}
}