1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   4 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 
 
 
 
   5 */
   6
   7#include <linux/spinlock.h>
   8#include <linux/completion.h>
   9#include <linux/buffer_head.h>
  10#include <linux/blkdev.h>
  11#include <linux/gfs2_ondisk.h>
  12#include <linux/crc32.h>
  13#include <linux/iomap.h>
  14#include <linux/ktime.h>
  15
  16#include "gfs2.h"
  17#include "incore.h"
  18#include "bmap.h"
  19#include "glock.h"
  20#include "inode.h"
  21#include "meta_io.h"
  22#include "quota.h"
  23#include "rgrp.h"
  24#include "log.h"
  25#include "super.h"
  26#include "trans.h"
  27#include "dir.h"
  28#include "util.h"
  29#include "aops.h"
  30#include "trace_gfs2.h"
  31
  32/* This doesn't need to be that large as max 64 bit pointers in a 4k
  33 * block is 512, so __u16 is fine for that. It saves stack space to
  34 * keep it small.
  35 */
  36struct metapath {
  37	struct buffer_head *mp_bh[GFS2_MAX_META_HEIGHT];
  38	__u16 mp_list[GFS2_MAX_META_HEIGHT];
  39	int mp_fheight; /* find_metapath height */
  40	int mp_aheight; /* actual height (lookup height) */
  41};
  42
  43static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length);
 
 
 
  44
  45/**
  46 * gfs2_unstuffer_folio - unstuff a stuffed inode into a block cached by a folio
  47 * @ip: the inode
  48 * @dibh: the dinode buffer
  49 * @block: the block number that was allocated
  50 * @folio: The folio.
  51 *
  52 * Returns: errno
  53 */
  54static int gfs2_unstuffer_folio(struct gfs2_inode *ip, struct buffer_head *dibh,
  55			       u64 block, struct folio *folio)
 
  56{
  57	struct inode *inode = &ip->i_inode;
 
 
  58
  59	if (!folio_test_uptodate(folio)) {
  60		void *kaddr = kmap_local_folio(folio, 0);
 
 
 
 
 
 
 
  61		u64 dsize = i_size_read(inode);
  62 
 
 
 
  63		memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
  64		memset(kaddr + dsize, 0, folio_size(folio) - dsize);
  65		kunmap_local(kaddr);
  66
  67		folio_mark_uptodate(folio);
  68	}
  69
  70	if (gfs2_is_jdata(ip)) {
  71		struct buffer_head *bh = folio_buffers(folio);
 
  72
  73		if (!bh)
  74			bh = create_empty_buffers(folio,
  75				BIT(inode->i_blkbits), BIT(BH_Uptodate));
  76
  77		if (!buffer_mapped(bh))
  78			map_bh(bh, inode->i_sb, block);
  79
  80		set_buffer_uptodate(bh);
  81		gfs2_trans_add_data(ip->i_gl, bh);
  82	} else {
  83		folio_mark_dirty(folio);
  84		gfs2_ordered_add_inode(ip);
 
 
 
 
  85	}
  86
  87	return 0;
  88}
  89
  90static int __gfs2_unstuff_inode(struct gfs2_inode *ip, struct folio *folio)
 
 
 
 
 
 
 
 
 
 
 
  91{
  92	struct buffer_head *bh, *dibh;
  93	struct gfs2_dinode *di;
  94	u64 block = 0;
  95	int isdir = gfs2_is_dir(ip);
  96	int error;
  97
 
 
  98	error = gfs2_meta_inode_buffer(ip, &dibh);
  99	if (error)
 100		return error;
 101
 102	if (i_size_read(&ip->i_inode)) {
 103		/* Get a free block, fill it with the stuffed data,
 104		   and write it out to disk */
 105
 106		unsigned int n = 1;
 107		error = gfs2_alloc_blocks(ip, &block, &n, 0);
 108		if (error)
 109			goto out_brelse;
 110		if (isdir) {
 111			gfs2_trans_remove_revoke(GFS2_SB(&ip->i_inode), block, 1);
 112			error = gfs2_dir_get_new_buffer(ip, block, &bh);
 113			if (error)
 114				goto out_brelse;
 115			gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_meta_header),
 116					      dibh, sizeof(struct gfs2_dinode));
 117			brelse(bh);
 118		} else {
 119			error = gfs2_unstuffer_folio(ip, dibh, block, folio);
 120			if (error)
 121				goto out_brelse;
 122		}
 123	}
 124
 125	/*  Set up the pointer to the new block  */
 126
 127	gfs2_trans_add_meta(ip->i_gl, dibh);
 128	di = (struct gfs2_dinode *)dibh->b_data;
 129	gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
 130
 131	if (i_size_read(&ip->i_inode)) {
 132		*(__be64 *)(di + 1) = cpu_to_be64(block);
 133		gfs2_add_inode_blocks(&ip->i_inode, 1);
 134		di->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode));
 135	}
 136
 137	ip->i_height = 1;
 138	di->di_height = cpu_to_be16(1);
 139
 140out_brelse:
 141	brelse(dibh);
 142	return error;
 143}
 144
 145/**
 146 * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big
 147 * @ip: The GFS2 inode to unstuff
 148 *
 149 * This routine unstuffs a dinode and returns it to a "normal" state such
 150 * that the height can be grown in the traditional way.
 151 *
 152 * Returns: errno
 153 */
 154
 155int gfs2_unstuff_dinode(struct gfs2_inode *ip)
 156{
 157	struct inode *inode = &ip->i_inode;
 158	struct folio *folio;
 159	int error;
 160
 161	down_write(&ip->i_rw_mutex);
 162	folio = filemap_grab_folio(inode->i_mapping, 0);
 163	error = PTR_ERR(folio);
 164	if (IS_ERR(folio))
 165		goto out;
 166	error = __gfs2_unstuff_inode(ip, folio);
 167	folio_unlock(folio);
 168	folio_put(folio);
 169out:
 170	up_write(&ip->i_rw_mutex);
 171	return error;
 172}
 173
 
 174/**
 175 * find_metapath - Find path through the metadata tree
 176 * @sdp: The superblock
 177 * @block: The disk block to look up
 178 * @mp: The metapath to return the result in
 
 179 * @height: The pre-calculated height of the metadata tree
 180 *
 181 *   This routine returns a struct metapath structure that defines a path
 182 *   through the metadata of inode "ip" to get to block "block".
 183 *
 184 *   Example:
 185 *   Given:  "ip" is a height 3 file, "offset" is 101342453, and this is a
 186 *   filesystem with a blocksize of 4096.
 187 *
 188 *   find_metapath() would return a struct metapath structure set to:
 189 *   mp_fheight = 3, mp_list[0] = 0, mp_list[1] = 48, and mp_list[2] = 165.
 
 190 *
 191 *   That means that in order to get to the block containing the byte at
 192 *   offset 101342453, we would load the indirect block pointed to by pointer
 193 *   0 in the dinode.  We would then load the indirect block pointed to by
 194 *   pointer 48 in that indirect block.  We would then load the data block
 195 *   pointed to by pointer 165 in that indirect block.
 196 *
 197 *             ----------------------------------------
 198 *             | Dinode |                             |
 199 *             |        |                            4|
 200 *             |        |0 1 2 3 4 5                 9|
 201 *             |        |                            6|
 202 *             ----------------------------------------
 203 *                       |
 204 *                       |
 205 *                       V
 206 *             ----------------------------------------
 207 *             | Indirect Block                       |
 208 *             |                                     5|
 209 *             |            4 4 4 4 4 5 5            1|
 210 *             |0           5 6 7 8 9 0 1            2|
 211 *             ----------------------------------------
 212 *                                |
 213 *                                |
 214 *                                V
 215 *             ----------------------------------------
 216 *             | Indirect Block                       |
 217 *             |                         1 1 1 1 1   5|
 218 *             |                         6 6 6 6 6   1|
 219 *             |0                        3 4 5 6 7   2|
 220 *             ----------------------------------------
 221 *                                           |
 222 *                                           |
 223 *                                           V
 224 *             ----------------------------------------
 225 *             | Data block containing offset         |
 226 *             |            101342453                 |
 227 *             |                                      |
 228 *             |                                      |
 229 *             ----------------------------------------
 230 *
 231 */
 232
 233static void find_metapath(const struct gfs2_sbd *sdp, u64 block,
 234			  struct metapath *mp, unsigned int height)
 235{
 236	unsigned int i;
 237
 238	mp->mp_fheight = height;
 239	for (i = height; i--;)
 240		mp->mp_list[i] = do_div(block, sdp->sd_inptrs);
 
 241}
 242
 243static inline unsigned int metapath_branch_start(const struct metapath *mp)
 244{
 245	if (mp->mp_list[0] == 0)
 246		return 2;
 247	return 1;
 248}
 249
 250/**
 251 * metaptr1 - Return the first possible metadata pointer in a metapath buffer
 252 * @height: The metadata height (0 = dinode)
 253 * @mp: The metapath
 254 */
 255static inline __be64 *metaptr1(unsigned int height, const struct metapath *mp)
 256{
 257	struct buffer_head *bh = mp->mp_bh[height];
 258	if (height == 0)
 259		return ((__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)));
 260	return ((__be64 *)(bh->b_data + sizeof(struct gfs2_meta_header)));
 261}
 262
 263/**
 264 * metapointer - Return pointer to start of metadata in a buffer
 265 * @height: The metadata height (0 = dinode)
 266 * @mp: The metapath
 267 *
 268 * Return a pointer to the block number of the next height of the metadata
 269 * tree given a buffer containing the pointer to the current height of the
 270 * metadata tree.
 271 */
 272
 273static inline __be64 *metapointer(unsigned int height, const struct metapath *mp)
 274{
 275	__be64 *p = metaptr1(height, mp);
 276	return p + mp->mp_list[height];
 277}
 278
 279static inline const __be64 *metaend(unsigned int height, const struct metapath *mp)
 280{
 281	const struct buffer_head *bh = mp->mp_bh[height];
 282	return (const __be64 *)(bh->b_data + bh->b_size);
 283}
 284
 285static void clone_metapath(struct metapath *clone, struct metapath *mp)
 286{
 287	unsigned int hgt;
 288
 289	*clone = *mp;
 290	for (hgt = 0; hgt < mp->mp_aheight; hgt++)
 291		get_bh(clone->mp_bh[hgt]);
 292}
 293
 294static void gfs2_metapath_ra(struct gfs2_glock *gl, __be64 *start, __be64 *end)
 
 295{
 
 
 296	const __be64 *t;
 297
 298	for (t = start; t < end; t++) {
 299		struct buffer_head *rabh;
 300
 301		if (!*t)
 302			continue;
 303
 304		rabh = gfs2_getbuf(gl, be64_to_cpu(*t), CREATE);
 305		if (trylock_buffer(rabh)) {
 306			if (!buffer_uptodate(rabh)) {
 307				rabh->b_end_io = end_buffer_read_sync;
 308				submit_bh(REQ_OP_READ | REQ_RAHEAD | REQ_META |
 309					  REQ_PRIO, rabh);
 310				continue;
 311			}
 312			unlock_buffer(rabh);
 313		}
 314		brelse(rabh);
 315	}
 316}
 317
 318static inline struct buffer_head *
 319metapath_dibh(struct metapath *mp)
 320{
 321	return mp->mp_bh[0];
 322}
 323
 324static int __fillup_metapath(struct gfs2_inode *ip, struct metapath *mp,
 325			     unsigned int x, unsigned int h)
 326{
 327	for (; x < h; x++) {
 328		__be64 *ptr = metapointer(x, mp);
 329		u64 dblock = be64_to_cpu(*ptr);
 330		int ret;
 331
 332		if (!dblock)
 333			break;
 334		ret = gfs2_meta_buffer(ip, GFS2_METATYPE_IN, dblock, &mp->mp_bh[x + 1]);
 335		if (ret)
 336			return ret;
 337	}
 338	mp->mp_aheight = x + 1;
 339	return 0;
 340}
 341
 342/**
 343 * lookup_metapath - Walk the metadata tree to a specific point
 344 * @ip: The inode
 345 * @mp: The metapath
 346 *
 347 * Assumes that the inode's buffer has already been looked up and
 348 * hooked onto mp->mp_bh[0] and that the metapath has been initialised
 349 * by find_metapath().
 350 *
 351 * If this function encounters part of the tree which has not been
 352 * allocated, it returns the current height of the tree at the point
 353 * at which it found the unallocated block. Blocks which are found are
 354 * added to the mp->mp_bh[] list.
 355 *
 356 * Returns: error
 357 */
 358
 359static int lookup_metapath(struct gfs2_inode *ip, struct metapath *mp)
 360{
 361	return __fillup_metapath(ip, mp, 0, ip->i_height - 1);
 362}
 363
 364/**
 365 * fillup_metapath - fill up buffers for the metadata path to a specific height
 366 * @ip: The inode
 367 * @mp: The metapath
 368 * @h: The height to which it should be mapped
 369 *
 370 * Similar to lookup_metapath, but does lookups for a range of heights
 371 *
 372 * Returns: error or the number of buffers filled
 373 */
 374
 375static int fillup_metapath(struct gfs2_inode *ip, struct metapath *mp, int h)
 376{
 377	unsigned int x = 0;
 378	int ret;
 379
 380	if (h) {
 381		/* find the first buffer we need to look up. */
 382		for (x = h - 1; x > 0; x--) {
 383			if (mp->mp_bh[x])
 384				break;
 385		}
 386	}
 387	ret = __fillup_metapath(ip, mp, x, h);
 388	if (ret)
 389		return ret;
 390	return mp->mp_aheight - x - 1;
 391}
 392
 393static sector_t metapath_to_block(struct gfs2_sbd *sdp, struct metapath *mp)
 394{
 395	sector_t factor = 1, block = 0;
 396	int hgt;
 397
 398	for (hgt = mp->mp_fheight - 1; hgt >= 0; hgt--) {
 399		if (hgt < mp->mp_aheight)
 400			block += mp->mp_list[hgt] * factor;
 401		factor *= sdp->sd_inptrs;
 402	}
 403	return block;
 
 404}
 405
 406static void release_metapath(struct metapath *mp)
 407{
 408	int i;
 409
 410	for (i = 0; i < GFS2_MAX_META_HEIGHT; i++) {
 411		if (mp->mp_bh[i] == NULL)
 412			break;
 413		brelse(mp->mp_bh[i]);
 414		mp->mp_bh[i] = NULL;
 415	}
 416}
 417
 418/**
 419 * gfs2_extent_length - Returns length of an extent of blocks
 420 * @bh: The metadata block
 421 * @ptr: Current position in @bh
 
 
 422 * @eob: Set to 1 if we hit "end of block"
 423 *
 
 
 
 
 424 * Returns: The length of the extent (minimum of one block)
 425 */
 426
 427static inline unsigned int gfs2_extent_length(struct buffer_head *bh, __be64 *ptr, int *eob)
 428{
 429	const __be64 *end = (__be64 *)(bh->b_data + bh->b_size);
 430	const __be64 *first = ptr;
 431	u64 d = be64_to_cpu(*ptr);
 432
 433	*eob = 0;
 434	do {
 435		ptr++;
 436		if (ptr >= end)
 437			break;
 438		d++;
 
 
 
 439	} while(be64_to_cpu(*ptr) == d);
 440	if (ptr >= end)
 441		*eob = 1;
 442	return ptr - first;
 443}
 444
 445enum walker_status { WALK_STOP, WALK_FOLLOW, WALK_CONTINUE };
 446
 447/*
 448 * gfs2_metadata_walker - walk an indirect block
 449 * @mp: Metapath to indirect block
 450 * @ptrs: Number of pointers to look at
 451 *
 452 * When returning WALK_FOLLOW, the walker must update @mp to point at the right
 453 * indirect block to follow.
 454 */
 455typedef enum walker_status (*gfs2_metadata_walker)(struct metapath *mp,
 456						   unsigned int ptrs);
 457
 458/*
 459 * gfs2_walk_metadata - walk a tree of indirect blocks
 460 * @inode: The inode
 461 * @mp: Starting point of walk
 462 * @max_len: Maximum number of blocks to walk
 463 * @walker: Called during the walk
 464 *
 465 * Returns 1 if the walk was stopped by @walker, 0 if we went past @max_len or
 466 * past the end of metadata, and a negative error code otherwise.
 467 */
 468
 469static int gfs2_walk_metadata(struct inode *inode, struct metapath *mp,
 470		u64 max_len, gfs2_metadata_walker walker)
 471{
 472	struct gfs2_inode *ip = GFS2_I(inode);
 473	struct gfs2_sbd *sdp = GFS2_SB(inode);
 474	u64 factor = 1;
 475	unsigned int hgt;
 476	int ret;
 477
 478	/*
 479	 * The walk starts in the lowest allocated indirect block, which may be
 480	 * before the position indicated by @mp.  Adjust @max_len accordingly
 481	 * to avoid a short walk.
 482	 */
 483	for (hgt = mp->mp_fheight - 1; hgt >= mp->mp_aheight; hgt--) {
 484		max_len += mp->mp_list[hgt] * factor;
 485		mp->mp_list[hgt] = 0;
 486		factor *= sdp->sd_inptrs;
 487	}
 488
 489	for (;;) {
 490		u16 start = mp->mp_list[hgt];
 491		enum walker_status status;
 492		unsigned int ptrs;
 493		u64 len;
 494
 495		/* Walk indirect block. */
 496		ptrs = (hgt >= 1 ? sdp->sd_inptrs : sdp->sd_diptrs) - start;
 497		len = ptrs * factor;
 498		if (len > max_len)
 499			ptrs = DIV_ROUND_UP_ULL(max_len, factor);
 500		status = walker(mp, ptrs);
 501		switch (status) {
 502		case WALK_STOP:
 503			return 1;
 504		case WALK_FOLLOW:
 505			BUG_ON(mp->mp_aheight == mp->mp_fheight);
 506			ptrs = mp->mp_list[hgt] - start;
 507			len = ptrs * factor;
 508			break;
 509		case WALK_CONTINUE:
 510			break;
 511		}
 512		if (len >= max_len)
 513			break;
 514		max_len -= len;
 515		if (status == WALK_FOLLOW)
 516			goto fill_up_metapath;
 517
 518lower_metapath:
 519		/* Decrease height of metapath. */
 520		brelse(mp->mp_bh[hgt]);
 521		mp->mp_bh[hgt] = NULL;
 522		mp->mp_list[hgt] = 0;
 523		if (!hgt)
 524			break;
 525		hgt--;
 526		factor *= sdp->sd_inptrs;
 527
 528		/* Advance in metadata tree. */
 529		(mp->mp_list[hgt])++;
 530		if (hgt) {
 531			if (mp->mp_list[hgt] >= sdp->sd_inptrs)
 532				goto lower_metapath;
 533		} else {
 534			if (mp->mp_list[hgt] >= sdp->sd_diptrs)
 535				break;
 536		}
 537
 538fill_up_metapath:
 539		/* Increase height of metapath. */
 540		ret = fillup_metapath(ip, mp, ip->i_height - 1);
 541		if (ret < 0)
 542			return ret;
 543		hgt += ret;
 544		for (; ret; ret--)
 545			do_div(factor, sdp->sd_inptrs);
 546		mp->mp_aheight = hgt + 1;
 547	}
 548	return 0;
 549}
 550
 551static enum walker_status gfs2_hole_walker(struct metapath *mp,
 552					   unsigned int ptrs)
 553{
 554	const __be64 *start, *ptr, *end;
 555	unsigned int hgt;
 556
 557	hgt = mp->mp_aheight - 1;
 558	start = metapointer(hgt, mp);
 559	end = start + ptrs;
 560
 561	for (ptr = start; ptr < end; ptr++) {
 562		if (*ptr) {
 563			mp->mp_list[hgt] += ptr - start;
 564			if (mp->mp_aheight == mp->mp_fheight)
 565				return WALK_STOP;
 566			return WALK_FOLLOW;
 567		}
 568	}
 569	return WALK_CONTINUE;
 570}
 571
 572/**
 573 * gfs2_hole_size - figure out the size of a hole
 574 * @inode: The inode
 575 * @lblock: The logical starting block number
 576 * @len: How far to look (in blocks)
 577 * @mp: The metapath at lblock
 578 * @iomap: The iomap to store the hole size in
 579 *
 580 * This function modifies @mp.
 581 *
 582 * Returns: errno on error
 583 */
 584static int gfs2_hole_size(struct inode *inode, sector_t lblock, u64 len,
 585			  struct metapath *mp, struct iomap *iomap)
 586{
 587	struct metapath clone;
 588	u64 hole_size;
 589	int ret;
 590
 591	clone_metapath(&clone, mp);
 592	ret = gfs2_walk_metadata(inode, &clone, len, gfs2_hole_walker);
 593	if (ret < 0)
 594		goto out;
 595
 596	if (ret == 1)
 597		hole_size = metapath_to_block(GFS2_SB(inode), &clone) - lblock;
 598	else
 599		hole_size = len;
 600	iomap->length = hole_size << inode->i_blkbits;
 601	ret = 0;
 602
 603out:
 604	release_metapath(&clone);
 605	return ret;
 606}
 607
 608static inline void gfs2_indirect_init(struct metapath *mp,
 609				      struct gfs2_glock *gl, unsigned int i,
 610				      unsigned offset, u64 bn)
 611{
 612	__be64 *ptr = (__be64 *)(mp->mp_bh[i - 1]->b_data +
 613		       ((i > 1) ? sizeof(struct gfs2_meta_header) :
 614				 sizeof(struct gfs2_dinode)));
 615	BUG_ON(i < 1);
 616	BUG_ON(mp->mp_bh[i] != NULL);
 617	mp->mp_bh[i] = gfs2_meta_new(gl, bn);
 618	gfs2_trans_add_meta(gl, mp->mp_bh[i]);
 619	gfs2_metatype_set(mp->mp_bh[i], GFS2_METATYPE_IN, GFS2_FORMAT_IN);
 620	gfs2_buffer_clear_tail(mp->mp_bh[i], sizeof(struct gfs2_meta_header));
 621	ptr += offset;
 622	*ptr = cpu_to_be64(bn);
 
 623}
 624
 625enum alloc_state {
 626	ALLOC_DATA = 0,
 627	ALLOC_GROW_DEPTH = 1,
 628	ALLOC_GROW_HEIGHT = 2,
 629	/* ALLOC_UNSTUFF = 3,   TBD and rather complicated */
 630};
 631
 632/**
 633 * __gfs2_iomap_alloc - Build a metadata tree of the requested height
 634 * @inode: The GFS2 inode
 635 * @iomap: The iomap structure
 636 * @mp: The metapath, with proper height information calculated
 
 
 
 
 637 *
 638 * In this routine we may have to alloc:
 639 *   i) Indirect blocks to grow the metadata tree height
 640 *  ii) Indirect blocks to fill in lower part of the metadata tree
 641 * iii) Data blocks
 642 *
 643 * This function is called after __gfs2_iomap_get, which works out the
 644 * total number of blocks which we need via gfs2_alloc_size.
 645 *
 646 * We then do the actual allocation asking for an extent at a time (if
 647 * enough contiguous free blocks are available, there will only be one
 648 * allocation request per call) and uses the state machine to initialise
 649 * the blocks in order.
 650 *
 651 * Right now, this function will allocate at most one indirect block
 652 * worth of data -- with a default block size of 4K, that's slightly
 653 * less than 2M.  If this limitation is ever removed to allow huge
 654 * allocations, we would probably still want to limit the iomap size we
 655 * return to avoid stalling other tasks during huge writes; the next
 656 * iomap iteration would then find the blocks already allocated.
 657 *
 658 * Returns: errno on error
 659 */
 660
 661static int __gfs2_iomap_alloc(struct inode *inode, struct iomap *iomap,
 662			      struct metapath *mp)
 
 
 
 663{
 664	struct gfs2_inode *ip = GFS2_I(inode);
 665	struct gfs2_sbd *sdp = GFS2_SB(inode);
 666	struct buffer_head *dibh = metapath_dibh(mp);
 667	u64 bn;
 
 668	unsigned n, i, blks, alloced = 0, iblks = 0, branch_start = 0;
 669	size_t dblks = iomap->length >> inode->i_blkbits;
 670	const unsigned end_of_metadata = mp->mp_fheight - 1;
 
 671	int ret;
 
 672	enum alloc_state state;
 673	__be64 *ptr;
 674	__be64 zero_bn = 0;
 675
 676	BUG_ON(mp->mp_aheight < 1);
 677	BUG_ON(dibh == NULL);
 678	BUG_ON(dblks < 1);
 679
 680	gfs2_trans_add_meta(ip->i_gl, dibh);
 681
 682	down_write(&ip->i_rw_mutex);
 683
 684	if (mp->mp_fheight == mp->mp_aheight) {
 685		/* Bottom indirect block exists */
 
 
 
 
 
 
 686		state = ALLOC_DATA;
 687	} else {
 688		/* Need to allocate indirect blocks */
 689		if (mp->mp_fheight == ip->i_height) {
 
 
 690			/* Writing into existing tree, extend tree down */
 691			iblks = mp->mp_fheight - mp->mp_aheight;
 692			state = ALLOC_GROW_DEPTH;
 693		} else {
 694			/* Building up tree height */
 695			state = ALLOC_GROW_HEIGHT;
 696			iblks = mp->mp_fheight - ip->i_height;
 697			branch_start = metapath_branch_start(mp);
 698			iblks += (mp->mp_fheight - branch_start);
 699		}
 700	}
 701
 702	/* start of the second part of the function (state machine) */
 703
 704	blks = dblks + iblks;
 705	i = mp->mp_aheight;
 706	do {
 
 707		n = blks - alloced;
 708		ret = gfs2_alloc_blocks(ip, &bn, &n, 0);
 709		if (ret)
 710			goto out;
 711		alloced += n;
 712		if (state != ALLOC_DATA || gfs2_is_jdata(ip))
 713			gfs2_trans_remove_revoke(sdp, bn, n);
 714		switch (state) {
 715		/* Growing height of tree */
 716		case ALLOC_GROW_HEIGHT:
 717			if (i == 1) {
 718				ptr = (__be64 *)(dibh->b_data +
 719						 sizeof(struct gfs2_dinode));
 720				zero_bn = *ptr;
 721			}
 722			for (; i - 1 < mp->mp_fheight - ip->i_height && n > 0;
 723			     i++, n--)
 724				gfs2_indirect_init(mp, ip->i_gl, i, 0, bn++);
 725			if (i - 1 == mp->mp_fheight - ip->i_height) {
 726				i--;
 727				gfs2_buffer_copy_tail(mp->mp_bh[i],
 728						sizeof(struct gfs2_meta_header),
 729						dibh, sizeof(struct gfs2_dinode));
 730				gfs2_buffer_clear_tail(dibh,
 731						sizeof(struct gfs2_dinode) +
 732						sizeof(__be64));
 733				ptr = (__be64 *)(mp->mp_bh[i]->b_data +
 734					sizeof(struct gfs2_meta_header));
 735				*ptr = zero_bn;
 736				state = ALLOC_GROW_DEPTH;
 737				for(i = branch_start; i < mp->mp_fheight; i++) {
 738					if (mp->mp_bh[i] == NULL)
 739						break;
 740					brelse(mp->mp_bh[i]);
 741					mp->mp_bh[i] = NULL;
 742				}
 743				i = branch_start;
 744			}
 745			if (n == 0)
 746				break;
 747			fallthrough;	/* To branching from existing tree */
 748		case ALLOC_GROW_DEPTH:
 749			if (i > 1 && i < mp->mp_fheight)
 750				gfs2_trans_add_meta(ip->i_gl, mp->mp_bh[i-1]);
 751			for (; i < mp->mp_fheight && n > 0; i++, n--)
 752				gfs2_indirect_init(mp, ip->i_gl, i,
 753						   mp->mp_list[i-1], bn++);
 754			if (i == mp->mp_fheight)
 755				state = ALLOC_DATA;
 756			if (n == 0)
 757				break;
 758			fallthrough;	/* To tree complete, adding data blocks */
 759		case ALLOC_DATA:
 760			BUG_ON(n > dblks);
 761			BUG_ON(mp->mp_bh[end_of_metadata] == NULL);
 762			gfs2_trans_add_meta(ip->i_gl, mp->mp_bh[end_of_metadata]);
 763			dblks = n;
 764			ptr = metapointer(end_of_metadata, mp);
 765			iomap->addr = bn << inode->i_blkbits;
 766			iomap->flags |= IOMAP_F_MERGED | IOMAP_F_NEW;
 767			while (n-- > 0)
 768				*ptr++ = cpu_to_be64(bn++);
 
 
 
 
 
 
 
 
 
 769			break;
 770		}
 771	} while (iomap->addr == IOMAP_NULL_ADDR);
 772
 773	iomap->type = IOMAP_MAPPED;
 774	iomap->length = (u64)dblks << inode->i_blkbits;
 775	ip->i_height = mp->mp_fheight;
 776	gfs2_add_inode_blocks(&ip->i_inode, alloced);
 777	gfs2_dinode_out(ip, dibh->b_data);
 778out:
 779	up_write(&ip->i_rw_mutex);
 780	return ret;
 
 781}
 782
 783#define IOMAP_F_GFS2_BOUNDARY IOMAP_F_PRIVATE
 784
 785/**
 786 * gfs2_alloc_size - Compute the maximum allocation size
 787 * @inode: The inode
 788 * @mp: The metapath
 789 * @size: Requested size in blocks
 
 790 *
 791 * Compute the maximum size of the next allocation at @mp.
 792 *
 793 * Returns: size in blocks
 794 */
 795static u64 gfs2_alloc_size(struct inode *inode, struct metapath *mp, u64 size)
 796{
 797	struct gfs2_inode *ip = GFS2_I(inode);
 798	struct gfs2_sbd *sdp = GFS2_SB(inode);
 799	const __be64 *first, *ptr, *end;
 800
 801	/*
 802	 * For writes to stuffed files, this function is called twice via
 803	 * __gfs2_iomap_get, before and after unstuffing. The size we return the
 804	 * first time needs to be large enough to get the reservation and
 805	 * allocation sizes right.  The size we return the second time must
 806	 * be exact or else __gfs2_iomap_alloc won't do the right thing.
 807	 */
 808
 809	if (gfs2_is_stuffed(ip) || mp->mp_fheight != mp->mp_aheight) {
 810		unsigned int maxsize = mp->mp_fheight > 1 ?
 811			sdp->sd_inptrs : sdp->sd_diptrs;
 812		maxsize -= mp->mp_list[mp->mp_fheight - 1];
 813		if (size > maxsize)
 814			size = maxsize;
 815		return size;
 816	}
 817
 818	first = metapointer(ip->i_height - 1, mp);
 819	end = metaend(ip->i_height - 1, mp);
 820	if (end - first > size)
 821		end = first + size;
 822	for (ptr = first; ptr < end; ptr++) {
 823		if (*ptr)
 824			break;
 825	}
 826	return ptr - first;
 827}
 828
 829/**
 830 * __gfs2_iomap_get - Map blocks from an inode to disk blocks
 831 * @inode: The inode
 832 * @pos: Starting position in bytes
 833 * @length: Length to map, in bytes
 834 * @flags: iomap flags
 835 * @iomap: The iomap structure
 836 * @mp: The metapath
 837 *
 838 * Returns: errno
 839 */
 840static int __gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
 841			    unsigned flags, struct iomap *iomap,
 842			    struct metapath *mp)
 843{
 844	struct gfs2_inode *ip = GFS2_I(inode);
 845	struct gfs2_sbd *sdp = GFS2_SB(inode);
 846	loff_t size = i_size_read(inode);
 
 
 847	__be64 *ptr;
 848	sector_t lblock;
 849	sector_t lblock_stop;
 850	int ret;
 851	int eob;
 852	u64 len;
 853	struct buffer_head *dibh = NULL, *bh;
 854	u8 height;
 855
 856	if (!length)
 857		return -EINVAL;
 858
 859	down_read(&ip->i_rw_mutex);
 
 
 
 
 
 
 
 
 
 860
 861	ret = gfs2_meta_inode_buffer(ip, &dibh);
 862	if (ret)
 863		goto unlock;
 864	mp->mp_bh[0] = dibh;
 865
 866	if (gfs2_is_stuffed(ip)) {
 867		if (flags & IOMAP_WRITE) {
 868			loff_t max_size = gfs2_max_stuffed_size(ip);
 869
 870			if (pos + length > max_size)
 871				goto unstuff;
 872			iomap->length = max_size;
 873		} else {
 874			if (pos >= size) {
 875				if (flags & IOMAP_REPORT) {
 876					ret = -ENOENT;
 877					goto unlock;
 878				} else {
 879					iomap->offset = pos;
 880					iomap->length = length;
 881					goto hole_found;
 882				}
 883			}
 884			iomap->length = size;
 885		}
 886		iomap->addr = (ip->i_no_addr << inode->i_blkbits) +
 887			      sizeof(struct gfs2_dinode);
 888		iomap->type = IOMAP_INLINE;
 889		iomap->inline_data = dibh->b_data + sizeof(struct gfs2_dinode);
 890		goto out;
 891	}
 892
 893unstuff:
 894	lblock = pos >> inode->i_blkbits;
 895	iomap->offset = lblock << inode->i_blkbits;
 896	lblock_stop = (pos + length - 1) >> inode->i_blkbits;
 897	len = lblock_stop - lblock + 1;
 898	iomap->length = len << inode->i_blkbits;
 899
 900	height = ip->i_height;
 901	while ((lblock + 1) * sdp->sd_sb.sb_bsize > sdp->sd_heightsize[height])
 
 902		height++;
 903	find_metapath(sdp, lblock, mp, height);
 
 904	if (height > ip->i_height || gfs2_is_stuffed(ip))
 905		goto do_alloc;
 906
 907	ret = lookup_metapath(ip, mp);
 908	if (ret)
 909		goto unlock;
 910
 911	if (mp->mp_aheight != ip->i_height)
 912		goto do_alloc;
 913
 914	ptr = metapointer(ip->i_height - 1, mp);
 915	if (*ptr == 0)
 916		goto do_alloc;
 917
 918	bh = mp->mp_bh[ip->i_height - 1];
 919	len = gfs2_extent_length(bh, ptr, &eob);
 920
 921	iomap->addr = be64_to_cpu(*ptr) << inode->i_blkbits;
 922	iomap->length = len << inode->i_blkbits;
 923	iomap->type = IOMAP_MAPPED;
 924	iomap->flags |= IOMAP_F_MERGED;
 925	if (eob)
 926		iomap->flags |= IOMAP_F_GFS2_BOUNDARY;
 927
 928out:
 929	iomap->bdev = inode->i_sb->s_bdev;
 930unlock:
 931	up_read(&ip->i_rw_mutex);
 932	return ret;
 933
 934do_alloc:
 935	if (flags & IOMAP_REPORT) {
 936		if (pos >= size)
 937			ret = -ENOENT;
 938		else if (height == ip->i_height)
 939			ret = gfs2_hole_size(inode, lblock, len, mp, iomap);
 940		else
 941			iomap->length = size - iomap->offset;
 942	} else if (flags & IOMAP_WRITE) {
 943		u64 alloc_size;
 944
 945		if (flags & IOMAP_DIRECT)
 946			goto out;  /* (see gfs2_file_direct_write) */
 947
 948		len = gfs2_alloc_size(inode, mp, len);
 949		alloc_size = len << inode->i_blkbits;
 950		if (alloc_size < iomap->length)
 951			iomap->length = alloc_size;
 952	} else {
 953		if (pos < size && height == ip->i_height)
 954			ret = gfs2_hole_size(inode, lblock, len, mp, iomap);
 955	}
 956hole_found:
 957	iomap->addr = IOMAP_NULL_ADDR;
 958	iomap->type = IOMAP_HOLE;
 959	goto out;
 960}
 961
 962static struct folio *
 963gfs2_iomap_get_folio(struct iomap_iter *iter, loff_t pos, unsigned len)
 
 
 964{
 965	struct inode *inode = iter->inode;
 966	unsigned int blockmask = i_blocksize(inode) - 1;
 967	struct gfs2_sbd *sdp = GFS2_SB(inode);
 968	unsigned int blocks;
 969	struct folio *folio;
 970	int status;
 971
 972	blocks = ((pos & blockmask) + len + blockmask) >> inode->i_blkbits;
 973	status = gfs2_trans_begin(sdp, RES_DINODE + blocks, 0);
 974	if (status)
 975		return ERR_PTR(status);
 976
 977	folio = iomap_get_folio(iter, pos, len);
 978	if (IS_ERR(folio))
 979		gfs2_trans_end(sdp);
 980	return folio;
 
 
 
 
 
 
 
 
 
 981}
 982
 983static void gfs2_iomap_put_folio(struct inode *inode, loff_t pos,
 984				 unsigned copied, struct folio *folio)
 985{
 986	struct gfs2_trans *tr = current->journal_info;
 987	struct gfs2_inode *ip = GFS2_I(inode);
 988	struct gfs2_sbd *sdp = GFS2_SB(inode);
 989
 990	if (!gfs2_is_stuffed(ip))
 991		gfs2_trans_add_databufs(ip, folio, offset_in_folio(folio, pos),
 992					copied);
 
 
 993
 994	folio_unlock(folio);
 995	folio_put(folio);
 
 
 
 
 
 
 
 
 
 
 
 
 996
 997	if (tr->tr_num_buf_new)
 998		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
 
 999
1000	gfs2_trans_end(sdp);
1001}
1002
1003static const struct iomap_folio_ops gfs2_iomap_folio_ops = {
1004	.get_folio = gfs2_iomap_get_folio,
1005	.put_folio = gfs2_iomap_put_folio,
1006};
1007
1008static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos,
1009				  loff_t length, unsigned flags,
1010				  struct iomap *iomap,
1011				  struct metapath *mp)
1012{
1013	struct gfs2_inode *ip = GFS2_I(inode);
1014	struct gfs2_sbd *sdp = GFS2_SB(inode);
1015	bool unstuff;
1016	int ret;
1017
1018	unstuff = gfs2_is_stuffed(ip) &&
1019		  pos + length > gfs2_max_stuffed_size(ip);
 
 
 
1020
1021	if (unstuff || iomap->type == IOMAP_HOLE) {
1022		unsigned int data_blocks, ind_blocks;
1023		struct gfs2_alloc_parms ap = {};
1024		unsigned int rblocks;
1025		struct gfs2_trans *tr;
1026
1027		gfs2_write_calc_reserv(ip, iomap->length, &data_blocks,
1028				       &ind_blocks);
1029		ap.target = data_blocks + ind_blocks;
1030		ret = gfs2_quota_lock_check(ip, &ap);
1031		if (ret)
1032			return ret;
1033
1034		ret = gfs2_inplace_reserve(ip, &ap);
1035		if (ret)
1036			goto out_qunlock;
1037
1038		rblocks = RES_DINODE + ind_blocks;
1039		if (gfs2_is_jdata(ip))
1040			rblocks += data_blocks;
1041		if (ind_blocks || data_blocks)
1042			rblocks += RES_STATFS + RES_QUOTA;
1043		if (inode == sdp->sd_rindex)
1044			rblocks += 2 * RES_STATFS;
1045		rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks);
1046
1047		ret = gfs2_trans_begin(sdp, rblocks,
1048				       iomap->length >> inode->i_blkbits);
1049		if (ret)
1050			goto out_trans_fail;
 
1051
1052		if (unstuff) {
1053			ret = gfs2_unstuff_dinode(ip);
1054			if (ret)
1055				goto out_trans_end;
1056			release_metapath(mp);
1057			ret = __gfs2_iomap_get(inode, iomap->offset,
1058					       iomap->length, flags, iomap, mp);
1059			if (ret)
1060				goto out_trans_end;
1061		}
 
1062
1063		if (iomap->type == IOMAP_HOLE) {
1064			ret = __gfs2_iomap_alloc(inode, iomap, mp);
1065			if (ret) {
1066				gfs2_trans_end(sdp);
1067				gfs2_inplace_release(ip);
1068				punch_hole(ip, iomap->offset, iomap->length);
1069				goto out_qunlock;
1070			}
1071		}
1072
1073		tr = current->journal_info;
1074		if (tr->tr_num_buf_new)
1075			__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
1076
1077		gfs2_trans_end(sdp);
 
 
 
1078	}
1079
1080	if (gfs2_is_stuffed(ip) || gfs2_is_jdata(ip))
1081		iomap->folio_ops = &gfs2_iomap_folio_ops;
1082	return 0;
1083
1084out_trans_end:
1085	gfs2_trans_end(sdp);
1086out_trans_fail:
1087	gfs2_inplace_release(ip);
1088out_qunlock:
1089	gfs2_quota_unlock(ip);
1090	return ret;
1091}
1092
1093static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
1094			    unsigned flags, struct iomap *iomap,
1095			    struct iomap *srcmap)
1096{
1097	struct gfs2_inode *ip = GFS2_I(inode);
1098	struct metapath mp = { .mp_aheight = 1, };
1099	int ret;
1100
1101	if (gfs2_is_jdata(ip))
1102		iomap->flags |= IOMAP_F_BUFFER_HEAD;
1103
1104	trace_gfs2_iomap_start(ip, pos, length, flags);
1105	ret = __gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);
1106	if (ret)
1107		goto out_unlock;
1108
1109	switch(flags & (IOMAP_WRITE | IOMAP_ZERO)) {
1110	case IOMAP_WRITE:
1111		if (flags & IOMAP_DIRECT) {
1112			/*
1113			 * Silently fall back to buffered I/O for stuffed files
1114			 * or if we've got a hole (see gfs2_file_direct_write).
1115			 */
1116			if (iomap->type != IOMAP_MAPPED)
1117				ret = -ENOTBLK;
1118			goto out_unlock;
1119		}
1120		break;
1121	case IOMAP_ZERO:
1122		if (iomap->type == IOMAP_HOLE)
1123			goto out_unlock;
1124		break;
1125	default:
1126		goto out_unlock;
1127	}
1128
1129	ret = gfs2_iomap_begin_write(inode, pos, length, flags, iomap, &mp);
1130
1131out_unlock:
1132	release_metapath(&mp);
1133	trace_gfs2_iomap_end(ip, iomap, ret);
1134	return ret;
1135}
 
 
1136
1137static int gfs2_iomap_end(struct inode *inode, loff_t pos, loff_t length,
1138			  ssize_t written, unsigned flags, struct iomap *iomap)
1139{
1140	struct gfs2_inode *ip = GFS2_I(inode);
1141	struct gfs2_sbd *sdp = GFS2_SB(inode);
1142
1143	switch (flags & (IOMAP_WRITE | IOMAP_ZERO)) {
1144	case IOMAP_WRITE:
1145		if (flags & IOMAP_DIRECT)
1146			return 0;
1147		break;
1148	case IOMAP_ZERO:
1149		 if (iomap->type == IOMAP_HOLE)
1150			 return 0;
1151		 break;
1152	default:
1153		 return 0;
1154	}
1155
1156	if (!gfs2_is_stuffed(ip))
1157		gfs2_ordered_add_inode(ip);
1158
1159	if (inode == sdp->sd_rindex)
1160		adjust_fs_space(inode);
 
1161
1162	gfs2_inplace_release(ip);
1163
1164	if (ip->i_qadata && ip->i_qadata->qa_qd_num)
1165		gfs2_quota_unlock(ip);
1166
1167	if (length != written && (iomap->flags & IOMAP_F_NEW)) {
1168		/* Deallocate blocks that were just allocated. */
1169		loff_t hstart = round_up(pos + written, i_blocksize(inode));
1170		loff_t hend = iomap->offset + iomap->length;
1171
1172		if (hstart < hend) {
1173			truncate_pagecache_range(inode, hstart, hend - 1);
1174			punch_hole(ip, hstart, hend - hstart);
1175		}
1176	}
1177
1178	if (unlikely(!written))
1179		return 0;
1180
1181	if (iomap->flags & IOMAP_F_SIZE_CHANGED)
1182		mark_inode_dirty(inode);
1183	set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
1184	return 0;
 
 
1185}
1186
1187const struct iomap_ops gfs2_iomap_ops = {
1188	.iomap_begin = gfs2_iomap_begin,
1189	.iomap_end = gfs2_iomap_end,
1190};
1191
1192/**
1193 * gfs2_block_map - Map one or more blocks of an inode to a disk block
1194 * @inode: The inode
1195 * @lblock: The logical block number
1196 * @bh_map: The bh to be mapped
1197 * @create: True if its ok to alloc blocks to satify the request
1198 *
1199 * The size of the requested mapping is defined in bh_map->b_size.
 
1200 *
1201 * Clears buffer_mapped(bh_map) and leaves bh_map->b_size unchanged
1202 * when @lblock is not mapped.  Sets buffer_mapped(bh_map) and
1203 * bh_map->b_size to indicate the size of the mapping when @lblock and
1204 * successive blocks are mapped, up to the requested size.
1205 *
1206 * Sets buffer_boundary() if a read of metadata will be required
1207 * before the next block can be mapped. Sets buffer_new() if new
1208 * blocks were allocated.
1209 *
1210 * Returns: errno
1211 */
1212
1213int gfs2_block_map(struct inode *inode, sector_t lblock,
1214		   struct buffer_head *bh_map, int create)
 
1215{
1216	struct gfs2_inode *ip = GFS2_I(inode);
1217	loff_t pos = (loff_t)lblock << inode->i_blkbits;
1218	loff_t length = bh_map->b_size;
1219	struct iomap iomap = { };
1220	int ret;
 
1221
1222	clear_buffer_mapped(bh_map);
1223	clear_buffer_new(bh_map);
1224	clear_buffer_boundary(bh_map);
1225	trace_gfs2_bmap(ip, bh_map, lblock, create, 1);
 
1226
1227	if (!create)
1228		ret = gfs2_iomap_get(inode, pos, length, &iomap);
1229	else
1230		ret = gfs2_iomap_alloc(inode, pos, length, &iomap);
1231	if (ret)
1232		goto out;
1233
1234	if (iomap.length > bh_map->b_size) {
1235		iomap.length = bh_map->b_size;
1236		iomap.flags &= ~IOMAP_F_GFS2_BOUNDARY;
1237	}
1238	if (iomap.addr != IOMAP_NULL_ADDR)
1239		map_bh(bh_map, inode->i_sb, iomap.addr >> inode->i_blkbits);
1240	bh_map->b_size = iomap.length;
1241	if (iomap.flags & IOMAP_F_GFS2_BOUNDARY)
1242		set_buffer_boundary(bh_map);
1243	if (iomap.flags & IOMAP_F_NEW)
1244		set_buffer_new(bh_map);
1245
1246out:
1247	trace_gfs2_bmap(ip, bh_map, lblock, create, ret);
1248	return ret;
1249}
1250
1251int gfs2_get_extent(struct inode *inode, u64 lblock, u64 *dblock,
1252		    unsigned int *extlen)
1253{
1254	unsigned int blkbits = inode->i_blkbits;
1255	struct iomap iomap = { };
1256	unsigned int len;
1257	int ret;
1258
1259	ret = gfs2_iomap_get(inode, lblock << blkbits, *extlen << blkbits,
1260			     &iomap);
1261	if (ret)
1262		return ret;
1263	if (iomap.type != IOMAP_MAPPED)
1264		return -EIO;
1265	*dblock = iomap.addr >> blkbits;
1266	len = iomap.length >> blkbits;
1267	if (len < *extlen)
1268		*extlen = len;
1269	return 0;
1270}
1271
1272int gfs2_alloc_extent(struct inode *inode, u64 lblock, u64 *dblock,
1273		      unsigned int *extlen, bool *new)
1274{
1275	unsigned int blkbits = inode->i_blkbits;
1276	struct iomap iomap = { };
1277	unsigned int len;
1278	int ret;
1279
1280	ret = gfs2_iomap_alloc(inode, lblock << blkbits, *extlen << blkbits,
1281			       &iomap);
1282	if (ret)
1283		return ret;
1284	if (iomap.type != IOMAP_MAPPED)
1285		return -EIO;
1286	*dblock = iomap.addr >> blkbits;
1287	len = iomap.length >> blkbits;
1288	if (len < *extlen)
1289		*extlen = len;
1290	*new = iomap.flags & IOMAP_F_NEW;
1291	return 0;
1292}
1293
1294/*
1295 * NOTE: Never call gfs2_block_zero_range with an open transaction because it
1296 * uses iomap write to perform its actions, which begin their own transactions
1297 * (iomap_begin, get_folio, etc.)
1298 */
1299static int gfs2_block_zero_range(struct inode *inode, loff_t from,
1300				 unsigned int length)
1301{
1302	BUG_ON(current->journal_info);
1303	return iomap_zero_range(inode, from, length, NULL, &gfs2_iomap_ops);
 
1304}
1305
1306#define GFS2_JTRUNC_REVOKES 8192
1307
1308/**
1309 * gfs2_journaled_truncate - Wrapper for truncate_pagecache for jdata files
1310 * @inode: The inode being truncated
1311 * @oldsize: The original (larger) size
1312 * @newsize: The new smaller size
1313 *
1314 * With jdata files, we have to journal a revoke for each block which is
1315 * truncated. As a result, we need to split this into separate transactions
1316 * if the number of pages being truncated gets too large.
1317 */
1318
1319static int gfs2_journaled_truncate(struct inode *inode, u64 oldsize, u64 newsize)
1320{
1321	struct gfs2_sbd *sdp = GFS2_SB(inode);
1322	u64 max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize;
1323	u64 chunk;
1324	int error;
 
 
 
 
1325
1326	while (oldsize != newsize) {
1327		struct gfs2_trans *tr;
1328		unsigned int offs;
1329
1330		chunk = oldsize - newsize;
1331		if (chunk > max_chunk)
1332			chunk = max_chunk;
1333
1334		offs = oldsize & ~PAGE_MASK;
1335		if (offs && chunk > PAGE_SIZE)
1336			chunk = offs + ((chunk - offs) & PAGE_MASK);
1337
1338		truncate_pagecache(inode, oldsize - chunk);
1339		oldsize -= chunk;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1340
1341		tr = current->journal_info;
1342		if (!test_bit(TR_TOUCHED, &tr->tr_flags))
1343			continue;
1344
1345		gfs2_trans_end(sdp);
1346		error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES);
1347		if (error)
1348			return error;
 
 
 
 
1349	}
1350
1351	return 0;
 
 
 
 
 
 
 
 
1352}
1353
1354static int trunc_start(struct inode *inode, u64 newsize)
1355{
1356	struct gfs2_inode *ip = GFS2_I(inode);
1357	struct gfs2_sbd *sdp = GFS2_SB(inode);
1358	struct buffer_head *dibh = NULL;
 
1359	int journaled = gfs2_is_jdata(ip);
1360	u64 oldsize = inode->i_size;
1361	int error;
1362
1363	if (!gfs2_is_stuffed(ip)) {
1364		unsigned int blocksize = i_blocksize(inode);
1365		unsigned int offs = newsize & (blocksize - 1);
1366		if (offs) {
1367			error = gfs2_block_zero_range(inode, newsize,
1368						      blocksize - offs);
1369			if (error)
1370				return error;
1371		}
1372	}
1373	if (journaled)
1374		error = gfs2_trans_begin(sdp, RES_DINODE + RES_JDATA, GFS2_JTRUNC_REVOKES);
1375	else
1376		error = gfs2_trans_begin(sdp, RES_DINODE, 0);
1377	if (error)
1378		return error;
1379
1380	error = gfs2_meta_inode_buffer(ip, &dibh);
1381	if (error)
1382		goto out;
1383
1384	gfs2_trans_add_meta(ip->i_gl, dibh);
1385
1386	if (gfs2_is_stuffed(ip))
1387		gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + newsize);
1388	else
 
 
 
 
 
1389		ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG;
 
1390
1391	i_size_write(inode, newsize);
1392	inode_set_mtime_to_ts(&ip->i_inode, inode_set_ctime_current(&ip->i_inode));
1393	gfs2_dinode_out(ip, dibh->b_data);
1394
1395	if (journaled)
1396		error = gfs2_journaled_truncate(inode, oldsize, newsize);
1397	else
1398		truncate_pagecache(inode, newsize);
1399
1400out:
1401	brelse(dibh);
1402	if (current->journal_info)
1403		gfs2_trans_end(sdp);
1404	return error;
1405}
1406
1407int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
1408		   struct iomap *iomap)
1409{
1410	struct metapath mp = { .mp_aheight = 1, };
1411	int ret;
1412
1413	ret = __gfs2_iomap_get(inode, pos, length, 0, iomap, &mp);
1414	release_metapath(&mp);
1415	return ret;
1416}
1417
1418int gfs2_iomap_alloc(struct inode *inode, loff_t pos, loff_t length,
1419		     struct iomap *iomap)
1420{
1421	struct metapath mp = { .mp_aheight = 1, };
1422	int ret;
1423
1424	ret = __gfs2_iomap_get(inode, pos, length, IOMAP_WRITE, iomap, &mp);
1425	if (!ret && iomap->type == IOMAP_HOLE)
1426		ret = __gfs2_iomap_alloc(inode, iomap, &mp);
1427	release_metapath(&mp);
1428	return ret;
1429}
1430
1431/**
1432 * sweep_bh_for_rgrps - find an rgrp in a meta buffer and free blocks therein
1433 * @ip: inode
1434 * @rd_gh: holder of resource group glock
1435 * @bh: buffer head to sweep
1436 * @start: starting point in bh
1437 * @end: end point in bh
1438 * @meta: true if bh points to metadata (rather than data)
1439 * @btotal: place to keep count of total blocks freed
1440 *
1441 * We sweep a metadata buffer (provided by the metapath) for blocks we need to
1442 * free, and free them all. However, we do it one rgrp at a time. If this
1443 * block has references to multiple rgrps, we break it into individual
1444 * transactions. This allows other processes to use the rgrps while we're
1445 * focused on a single one, for better concurrency / performance.
1446 * At every transaction boundary, we rewrite the inode into the journal.
1447 * That way the bitmaps are kept consistent with the inode and we can recover
1448 * if we're interrupted by power-outages.
1449 *
1450 * Returns: 0, or return code if an error occurred.
1451 *          *btotal has the total number of blocks freed
1452 */
1453static int sweep_bh_for_rgrps(struct gfs2_inode *ip, struct gfs2_holder *rd_gh,
1454			      struct buffer_head *bh, __be64 *start, __be64 *end,
1455			      bool meta, u32 *btotal)
1456{
1457	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1458	struct gfs2_rgrpd *rgd;
1459	struct gfs2_trans *tr;
1460	__be64 *p;
1461	int blks_outside_rgrp;
1462	u64 bn, bstart, isize_blks;
1463	s64 blen; /* needs to be s64 or gfs2_add_inode_blocks breaks */
1464	int ret = 0;
1465	bool buf_in_tr = false; /* buffer was added to transaction */
1466
1467more_rgrps:
1468	rgd = NULL;
1469	if (gfs2_holder_initialized(rd_gh)) {
1470		rgd = gfs2_glock2rgrp(rd_gh->gh_gl);
1471		gfs2_assert_withdraw(sdp,
1472			     gfs2_glock_is_locked_by_me(rd_gh->gh_gl));
1473	}
1474	blks_outside_rgrp = 0;
1475	bstart = 0;
1476	blen = 0;
1477
1478	for (p = start; p < end; p++) {
1479		if (!*p)
1480			continue;
1481		bn = be64_to_cpu(*p);
1482
1483		if (rgd) {
1484			if (!rgrp_contains_block(rgd, bn)) {
1485				blks_outside_rgrp++;
1486				continue;
1487			}
1488		} else {
1489			rgd = gfs2_blk2rgrpd(sdp, bn, true);
1490			if (unlikely(!rgd)) {
1491				ret = -EIO;
1492				goto out;
1493			}
1494			ret = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE,
1495						 LM_FLAG_NODE_SCOPE, rd_gh);
1496			if (ret)
1497				goto out;
1498
1499			/* Must be done with the rgrp glock held: */
1500			if (gfs2_rs_active(&ip->i_res) &&
1501			    rgd == ip->i_res.rs_rgd)
1502				gfs2_rs_deltree(&ip->i_res);
1503		}
1504
1505		/* The size of our transactions will be unknown until we
1506		   actually process all the metadata blocks that relate to
1507		   the rgrp. So we estimate. We know it can't be more than
1508		   the dinode's i_blocks and we don't want to exceed the
1509		   journal flush threshold, sd_log_thresh2. */
1510		if (current->journal_info == NULL) {
1511			unsigned int jblocks_rqsted, revokes;
1512
1513			jblocks_rqsted = rgd->rd_length + RES_DINODE +
1514				RES_INDIRECT;
1515			isize_blks = gfs2_get_inode_blocks(&ip->i_inode);
1516			if (isize_blks > atomic_read(&sdp->sd_log_thresh2))
1517				jblocks_rqsted +=
1518					atomic_read(&sdp->sd_log_thresh2);
1519			else
1520				jblocks_rqsted += isize_blks;
1521			revokes = jblocks_rqsted;
1522			if (meta)
1523				revokes += end - start;
1524			else if (ip->i_depth)
1525				revokes += sdp->sd_inptrs;
1526			ret = gfs2_trans_begin(sdp, jblocks_rqsted, revokes);
1527			if (ret)
1528				goto out_unlock;
1529			down_write(&ip->i_rw_mutex);
1530		}
1531		/* check if we will exceed the transaction blocks requested */
1532		tr = current->journal_info;
1533		if (tr->tr_num_buf_new + RES_STATFS +
1534		    RES_QUOTA >= atomic_read(&sdp->sd_log_thresh2)) {
1535			/* We set blks_outside_rgrp to ensure the loop will
1536			   be repeated for the same rgrp, but with a new
1537			   transaction. */
1538			blks_outside_rgrp++;
1539			/* This next part is tricky. If the buffer was added
1540			   to the transaction, we've already set some block
1541			   pointers to 0, so we better follow through and free
1542			   them, or we will introduce corruption (so break).
1543			   This may be impossible, or at least rare, but I
1544			   decided to cover the case regardless.
1545
1546			   If the buffer was not added to the transaction
1547			   (this call), doing so would exceed our transaction
1548			   size, so we need to end the transaction and start a
1549			   new one (so goto). */
1550
1551			if (buf_in_tr)
1552				break;
1553			goto out_unlock;
1554		}
1555
1556		gfs2_trans_add_meta(ip->i_gl, bh);
1557		buf_in_tr = true;
1558		*p = 0;
1559		if (bstart + blen == bn) {
1560			blen++;
1561			continue;
1562		}
1563		if (bstart) {
1564			__gfs2_free_blocks(ip, rgd, bstart, (u32)blen, meta);
1565			(*btotal) += blen;
1566			gfs2_add_inode_blocks(&ip->i_inode, -blen);
1567		}
1568		bstart = bn;
1569		blen = 1;
1570	}
1571	if (bstart) {
1572		__gfs2_free_blocks(ip, rgd, bstart, (u32)blen, meta);
1573		(*btotal) += blen;
1574		gfs2_add_inode_blocks(&ip->i_inode, -blen);
1575	}
1576out_unlock:
1577	if (!ret && blks_outside_rgrp) { /* If buffer still has non-zero blocks
1578					    outside the rgrp we just processed,
1579					    do it all over again. */
1580		if (current->journal_info) {
1581			struct buffer_head *dibh;
1582
1583			ret = gfs2_meta_inode_buffer(ip, &dibh);
1584			if (ret)
1585				goto out;
1586
1587			/* Every transaction boundary, we rewrite the dinode
1588			   to keep its di_blocks current in case of failure. */
1589			inode_set_mtime_to_ts(&ip->i_inode, inode_set_ctime_current(&ip->i_inode));
1590			gfs2_trans_add_meta(ip->i_gl, dibh);
1591			gfs2_dinode_out(ip, dibh->b_data);
1592			brelse(dibh);
1593			up_write(&ip->i_rw_mutex);
1594			gfs2_trans_end(sdp);
1595			buf_in_tr = false;
1596		}
1597		gfs2_glock_dq_uninit(rd_gh);
1598		cond_resched();
1599		goto more_rgrps;
1600	}
1601out:
1602	return ret;
1603}
1604
1605static bool mp_eq_to_hgt(struct metapath *mp, __u16 *list, unsigned int h)
1606{
1607	if (memcmp(mp->mp_list, list, h * sizeof(mp->mp_list[0])))
1608		return false;
1609	return true;
1610}
1611
1612/**
1613 * find_nonnull_ptr - find a non-null pointer given a metapath and height
1614 * @sdp: The superblock
1615 * @mp: starting metapath
1616 * @h: desired height to search
1617 * @end_list: See punch_hole().
1618 * @end_aligned: See punch_hole().
1619 *
1620 * Assumes the metapath is valid (with buffers) out to height h.
1621 * Returns: true if a non-null pointer was found in the metapath buffer
1622 *          false if all remaining pointers are NULL in the buffer
1623 */
1624static bool find_nonnull_ptr(struct gfs2_sbd *sdp, struct metapath *mp,
1625			     unsigned int h,
1626			     __u16 *end_list, unsigned int end_aligned)
1627{
1628	struct buffer_head *bh = mp->mp_bh[h];
1629	__be64 *first, *ptr, *end;
1630
1631	first = metaptr1(h, mp);
1632	ptr = first + mp->mp_list[h];
1633	end = (__be64 *)(bh->b_data + bh->b_size);
1634	if (end_list && mp_eq_to_hgt(mp, end_list, h)) {
1635		bool keep_end = h < end_aligned;
1636		end = first + end_list[h] + keep_end;
1637	}
1638
1639	while (ptr < end) {
1640		if (*ptr) { /* if we have a non-null pointer */
1641			mp->mp_list[h] = ptr - first;
1642			h++;
1643			if (h < GFS2_MAX_META_HEIGHT)
1644				mp->mp_list[h] = 0;
1645			return true;
1646		}
1647		ptr++;
1648	}
1649	return false;
1650}
1651
1652enum dealloc_states {
1653	DEALLOC_MP_FULL = 0,    /* Strip a metapath with all buffers read in */
1654	DEALLOC_MP_LOWER = 1,   /* lower the metapath strip height */
1655	DEALLOC_FILL_MP = 2,  /* Fill in the metapath to the given height. */
1656	DEALLOC_DONE = 3,       /* process complete */
1657};
1658
1659static inline void
1660metapointer_range(struct metapath *mp, int height,
1661		  __u16 *start_list, unsigned int start_aligned,
1662		  __u16 *end_list, unsigned int end_aligned,
1663		  __be64 **start, __be64 **end)
1664{
1665	struct buffer_head *bh = mp->mp_bh[height];
1666	__be64 *first;
1667
1668	first = metaptr1(height, mp);
1669	*start = first;
1670	if (mp_eq_to_hgt(mp, start_list, height)) {
1671		bool keep_start = height < start_aligned;
1672		*start = first + start_list[height] + keep_start;
1673	}
1674	*end = (__be64 *)(bh->b_data + bh->b_size);
1675	if (end_list && mp_eq_to_hgt(mp, end_list, height)) {
1676		bool keep_end = height < end_aligned;
1677		*end = first + end_list[height] + keep_end;
1678	}
1679}
1680
1681static inline bool walk_done(struct gfs2_sbd *sdp,
1682			     struct metapath *mp, int height,
1683			     __u16 *end_list, unsigned int end_aligned)
1684{
1685	__u16 end;
1686
1687	if (end_list) {
1688		bool keep_end = height < end_aligned;
1689		if (!mp_eq_to_hgt(mp, end_list, height))
1690			return false;
1691		end = end_list[height] + keep_end;
1692	} else
1693		end = (height > 0) ? sdp->sd_inptrs : sdp->sd_diptrs;
1694	return mp->mp_list[height] >= end;
1695}
1696
1697/**
1698 * punch_hole - deallocate blocks in a file
1699 * @ip: inode to truncate
1700 * @offset: the start of the hole
1701 * @length: the size of the hole (or 0 for truncate)
1702 *
1703 * Punch a hole into a file or truncate a file at a given position.  This
1704 * function operates in whole blocks (@offset and @length are rounded
1705 * accordingly); partially filled blocks must be cleared otherwise.
1706 *
1707 * This function works from the bottom up, and from the right to the left. In
1708 * other words, it strips off the highest layer (data) before stripping any of
1709 * the metadata. Doing it this way is best in case the operation is interrupted
1710 * by power failure, etc.  The dinode is rewritten in every transaction to
1711 * guarantee integrity.
1712 */
1713static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length)
1714{
1715	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1716	u64 maxsize = sdp->sd_heightsize[ip->i_height];
1717	struct metapath mp = {};
1718	struct buffer_head *dibh, *bh;
1719	struct gfs2_holder rd_gh;
1720	unsigned int bsize_shift = sdp->sd_sb.sb_bsize_shift;
1721	unsigned int bsize = 1 << bsize_shift;
1722	u64 lblock = (offset + bsize - 1) >> bsize_shift;
1723	__u16 start_list[GFS2_MAX_META_HEIGHT];
1724	__u16 __end_list[GFS2_MAX_META_HEIGHT], *end_list = NULL;
1725	unsigned int start_aligned, end_aligned;
1726	unsigned int strip_h = ip->i_height - 1;
1727	u32 btotal = 0;
1728	int ret, state;
1729	int mp_h; /* metapath buffers are read in to this height */
1730	u64 prev_bnr = 0;
1731	__be64 *start, *end;
1732
1733	if (offset + bsize - 1 >= maxsize) {
1734		/*
1735		 * The starting point lies beyond the allocated metadata;
1736		 * there are no blocks to deallocate.
1737		 */
1738		return 0;
1739	}
1740
1741	/*
1742	 * The start position of the hole is defined by lblock, start_list, and
1743	 * start_aligned.  The end position of the hole is defined by lend,
1744	 * end_list, and end_aligned.
1745	 *
1746	 * start_aligned and end_aligned define down to which height the start
1747	 * and end positions are aligned to the metadata tree (i.e., the
1748	 * position is a multiple of the metadata granularity at the height
1749	 * above).  This determines at which heights additional meta pointers
1750	 * needs to be preserved for the remaining data.
1751	 */
1752
1753	if (length) {
1754		u64 end_offset = offset + length;
1755		u64 lend;
1756
1757		/*
1758		 * Clip the end at the maximum file size for the given height:
1759		 * that's how far the metadata goes; files bigger than that
1760		 * will have additional layers of indirection.
1761		 */
1762		if (end_offset > maxsize)
1763			end_offset = maxsize;
1764		lend = end_offset >> bsize_shift;
1765
1766		if (lblock >= lend)
1767			return 0;
1768
1769		find_metapath(sdp, lend, &mp, ip->i_height);
1770		end_list = __end_list;
1771		memcpy(end_list, mp.mp_list, sizeof(mp.mp_list));
1772
1773		for (mp_h = ip->i_height - 1; mp_h > 0; mp_h--) {
1774			if (end_list[mp_h])
1775				break;
1776		}
1777		end_aligned = mp_h;
1778	}
1779
1780	find_metapath(sdp, lblock, &mp, ip->i_height);
1781	memcpy(start_list, mp.mp_list, sizeof(start_list));
1782
1783	for (mp_h = ip->i_height - 1; mp_h > 0; mp_h--) {
1784		if (start_list[mp_h])
1785			break;
1786	}
1787	start_aligned = mp_h;
1788
1789	ret = gfs2_meta_inode_buffer(ip, &dibh);
1790	if (ret)
1791		return ret;
1792
1793	mp.mp_bh[0] = dibh;
1794	ret = lookup_metapath(ip, &mp);
1795	if (ret)
1796		goto out_metapath;
1797
1798	/* issue read-ahead on metadata */
1799	for (mp_h = 0; mp_h < mp.mp_aheight - 1; mp_h++) {
1800		metapointer_range(&mp, mp_h, start_list, start_aligned,
1801				  end_list, end_aligned, &start, &end);
1802		gfs2_metapath_ra(ip->i_gl, start, end);
1803	}
1804
1805	if (mp.mp_aheight == ip->i_height)
1806		state = DEALLOC_MP_FULL; /* We have a complete metapath */
1807	else
1808		state = DEALLOC_FILL_MP; /* deal with partial metapath */
1809
1810	ret = gfs2_rindex_update(sdp);
1811	if (ret)
1812		goto out_metapath;
1813
1814	ret = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1815	if (ret)
1816		goto out_metapath;
1817	gfs2_holder_mark_uninitialized(&rd_gh);
1818
1819	mp_h = strip_h;
1820
1821	while (state != DEALLOC_DONE) {
1822		switch (state) {
1823		/* Truncate a full metapath at the given strip height.
1824		 * Note that strip_h == mp_h in order to be in this state. */
1825		case DEALLOC_MP_FULL:
1826			bh = mp.mp_bh[mp_h];
1827			gfs2_assert_withdraw(sdp, bh);
1828			if (gfs2_assert_withdraw(sdp,
1829						 prev_bnr != bh->b_blocknr)) {
1830				fs_emerg(sdp, "inode %llu, block:%llu, i_h:%u, "
1831					 "s_h:%u, mp_h:%u\n",
1832				       (unsigned long long)ip->i_no_addr,
1833				       prev_bnr, ip->i_height, strip_h, mp_h);
1834			}
1835			prev_bnr = bh->b_blocknr;
1836
1837			if (gfs2_metatype_check(sdp, bh,
1838						(mp_h ? GFS2_METATYPE_IN :
1839							GFS2_METATYPE_DI))) {
1840				ret = -EIO;
1841				goto out;
1842			}
1843
1844			/*
1845			 * Below, passing end_aligned as 0 gives us the
1846			 * metapointer range excluding the end point: the end
1847			 * point is the first metapath we must not deallocate!
1848			 */
1849
1850			metapointer_range(&mp, mp_h, start_list, start_aligned,
1851					  end_list, 0 /* end_aligned */,
1852					  &start, &end);
1853			ret = sweep_bh_for_rgrps(ip, &rd_gh, mp.mp_bh[mp_h],
1854						 start, end,
1855						 mp_h != ip->i_height - 1,
1856						 &btotal);
1857
1858			/* If we hit an error or just swept dinode buffer,
1859			   just exit. */
1860			if (ret || !mp_h) {
1861				state = DEALLOC_DONE;
1862				break;
1863			}
1864			state = DEALLOC_MP_LOWER;
1865			break;
1866
1867		/* lower the metapath strip height */
1868		case DEALLOC_MP_LOWER:
1869			/* We're done with the current buffer, so release it,
1870			   unless it's the dinode buffer. Then back up to the
1871			   previous pointer. */
1872			if (mp_h) {
1873				brelse(mp.mp_bh[mp_h]);
1874				mp.mp_bh[mp_h] = NULL;
1875			}
1876			/* If we can't get any lower in height, we've stripped
1877			   off all we can. Next step is to back up and start
1878			   stripping the previous level of metadata. */
1879			if (mp_h == 0) {
1880				strip_h--;
1881				memcpy(mp.mp_list, start_list, sizeof(start_list));
1882				mp_h = strip_h;
1883				state = DEALLOC_FILL_MP;
1884				break;
1885			}
1886			mp.mp_list[mp_h] = 0;
1887			mp_h--; /* search one metadata height down */
1888			mp.mp_list[mp_h]++;
1889			if (walk_done(sdp, &mp, mp_h, end_list, end_aligned))
1890				break;
1891			/* Here we've found a part of the metapath that is not
1892			 * allocated. We need to search at that height for the
1893			 * next non-null pointer. */
1894			if (find_nonnull_ptr(sdp, &mp, mp_h, end_list, end_aligned)) {
1895				state = DEALLOC_FILL_MP;
1896				mp_h++;
1897			}
1898			/* No more non-null pointers at this height. Back up
1899			   to the previous height and try again. */
1900			break; /* loop around in the same state */
1901
1902		/* Fill the metapath with buffers to the given height. */
1903		case DEALLOC_FILL_MP:
1904			/* Fill the buffers out to the current height. */
1905			ret = fillup_metapath(ip, &mp, mp_h);
1906			if (ret < 0)
1907				goto out;
1908
1909			/* On the first pass, issue read-ahead on metadata. */
1910			if (mp.mp_aheight > 1 && strip_h == ip->i_height - 1) {
1911				unsigned int height = mp.mp_aheight - 1;
1912
1913				/* No read-ahead for data blocks. */
1914				if (mp.mp_aheight - 1 == strip_h)
1915					height--;
1916
1917				for (; height >= mp.mp_aheight - ret; height--) {
1918					metapointer_range(&mp, height,
1919							  start_list, start_aligned,
1920							  end_list, end_aligned,
1921							  &start, &end);
1922					gfs2_metapath_ra(ip->i_gl, start, end);
1923				}
1924			}
1925
1926			/* If buffers found for the entire strip height */
1927			if (mp.mp_aheight - 1 == strip_h) {
1928				state = DEALLOC_MP_FULL;
1929				break;
1930			}
1931			if (mp.mp_aheight < ip->i_height) /* We have a partial height */
1932				mp_h = mp.mp_aheight - 1;
1933
1934			/* If we find a non-null block pointer, crawl a bit
1935			   higher up in the metapath and try again, otherwise
1936			   we need to look lower for a new starting point. */
1937			if (find_nonnull_ptr(sdp, &mp, mp_h, end_list, end_aligned))
1938				mp_h++;
1939			else
1940				state = DEALLOC_MP_LOWER;
1941			break;
1942		}
1943	}
1944
1945	if (btotal) {
1946		if (current->journal_info == NULL) {
1947			ret = gfs2_trans_begin(sdp, RES_DINODE + RES_STATFS +
1948					       RES_QUOTA, 0);
1949			if (ret)
1950				goto out;
1951			down_write(&ip->i_rw_mutex);
1952		}
1953		gfs2_statfs_change(sdp, 0, +btotal, 0);
1954		gfs2_quota_change(ip, -(s64)btotal, ip->i_inode.i_uid,
1955				  ip->i_inode.i_gid);
1956		inode_set_mtime_to_ts(&ip->i_inode, inode_set_ctime_current(&ip->i_inode));
1957		gfs2_trans_add_meta(ip->i_gl, dibh);
1958		gfs2_dinode_out(ip, dibh->b_data);
1959		up_write(&ip->i_rw_mutex);
1960		gfs2_trans_end(sdp);
1961	}
1962
1963out:
1964	if (gfs2_holder_initialized(&rd_gh))
1965		gfs2_glock_dq_uninit(&rd_gh);
1966	if (current->journal_info) {
1967		up_write(&ip->i_rw_mutex);
1968		gfs2_trans_end(sdp);
1969		cond_resched();
1970	}
1971	gfs2_quota_unhold(ip);
1972out_metapath:
1973	release_metapath(&mp);
1974	return ret;
1975}
1976
1977static int trunc_end(struct gfs2_inode *ip)
1978{
1979	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1980	struct buffer_head *dibh;
1981	int error;
1982
1983	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
1984	if (error)
1985		return error;
1986
1987	down_write(&ip->i_rw_mutex);
1988
1989	error = gfs2_meta_inode_buffer(ip, &dibh);
1990	if (error)
1991		goto out;
1992
1993	if (!i_size_read(&ip->i_inode)) {
1994		ip->i_height = 0;
1995		ip->i_goal = ip->i_no_addr;
1996		gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
1997		gfs2_ordered_del_inode(ip);
1998	}
1999	inode_set_mtime_to_ts(&ip->i_inode, inode_set_ctime_current(&ip->i_inode));
2000	ip->i_diskflags &= ~GFS2_DIF_TRUNC_IN_PROG;
2001
2002	gfs2_trans_add_meta(ip->i_gl, dibh);
2003	gfs2_dinode_out(ip, dibh->b_data);
2004	brelse(dibh);
2005
2006out:
2007	up_write(&ip->i_rw_mutex);
2008	gfs2_trans_end(sdp);
2009	return error;
2010}
2011
2012/**
2013 * do_shrink - make a file smaller
2014 * @inode: the inode
 
2015 * @newsize: the size to make the file
2016 *
2017 * Called with an exclusive lock on @inode. The @size must
2018 * be equal to or smaller than the current inode size.
2019 *
2020 * Returns: errno
2021 */
2022
2023static int do_shrink(struct inode *inode, u64 newsize)
2024{
2025	struct gfs2_inode *ip = GFS2_I(inode);
2026	int error;
2027
2028	error = trunc_start(inode, newsize);
2029	if (error < 0)
2030		return error;
2031	if (gfs2_is_stuffed(ip))
2032		return 0;
2033
2034	error = punch_hole(ip, newsize, 0);
2035	if (error == 0)
2036		error = trunc_end(ip);
2037
2038	return error;
2039}
2040
 
 
 
 
 
 
 
 
 
2041/**
2042 * do_grow - Touch and update inode size
2043 * @inode: The inode
2044 * @size: The new size
2045 *
2046 * This function updates the timestamps on the inode and
2047 * may also increase the size of the inode. This function
2048 * must not be called with @size any smaller than the current
2049 * inode size.
2050 *
2051 * Although it is not strictly required to unstuff files here,
2052 * earlier versions of GFS2 have a bug in the stuffed file reading
2053 * code which will result in a buffer overrun if the size is larger
2054 * than the max stuffed file size. In order to prevent this from
2055 * occurring, such files are unstuffed, but in other cases we can
2056 * just update the inode size directly.
2057 *
2058 * Returns: 0 on success, or -ve on error
2059 */
2060
2061static int do_grow(struct inode *inode, u64 size)
2062{
2063	struct gfs2_inode *ip = GFS2_I(inode);
2064	struct gfs2_sbd *sdp = GFS2_SB(inode);
2065	struct gfs2_alloc_parms ap = { .target = 1, };
2066	struct buffer_head *dibh;
 
2067	int error;
2068	int unstuff = 0;
2069
2070	if (gfs2_is_stuffed(ip) && size > gfs2_max_stuffed_size(ip)) {
2071		error = gfs2_quota_lock_check(ip, &ap);
 
 
 
 
 
2072		if (error)
2073			return error;
2074
2075		error = gfs2_inplace_reserve(ip, &ap);
2076		if (error)
2077			goto do_grow_qunlock;
2078		unstuff = 1;
2079	}
2080
2081	error = gfs2_trans_begin(sdp, RES_DINODE + RES_STATFS + RES_RG_BIT +
2082				 (unstuff &&
2083				  gfs2_is_jdata(ip) ? RES_JDATA : 0) +
2084				 (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF ?
2085				  0 : RES_QUOTA), 0);
2086	if (error)
2087		goto do_grow_release;
2088
2089	if (unstuff) {
2090		error = gfs2_unstuff_dinode(ip);
2091		if (error)
2092			goto do_end_trans;
2093	}
2094
2095	error = gfs2_meta_inode_buffer(ip, &dibh);
2096	if (error)
2097		goto do_end_trans;
2098
2099	truncate_setsize(inode, size);
2100	inode_set_mtime_to_ts(&ip->i_inode, inode_set_ctime_current(&ip->i_inode));
2101	gfs2_trans_add_meta(ip->i_gl, dibh);
2102	gfs2_dinode_out(ip, dibh->b_data);
2103	brelse(dibh);
2104
2105do_end_trans:
2106	gfs2_trans_end(sdp);
2107do_grow_release:
2108	if (unstuff) {
2109		gfs2_inplace_release(ip);
2110do_grow_qunlock:
2111		gfs2_quota_unlock(ip);
 
 
2112	}
2113	return error;
2114}
2115
2116/**
2117 * gfs2_setattr_size - make a file a given size
2118 * @inode: the inode
2119 * @newsize: the size to make the file
2120 *
2121 * The file size can grow, shrink, or stay the same size. This
2122 * is called holding i_rwsem and an exclusive glock on the inode
2123 * in question.
2124 *
2125 * Returns: errno
2126 */
2127
2128int gfs2_setattr_size(struct inode *inode, u64 newsize)
2129{
2130	struct gfs2_inode *ip = GFS2_I(inode);
2131	int ret;
 
2132
2133	BUG_ON(!S_ISREG(inode->i_mode));
2134
2135	ret = inode_newsize_ok(inode, newsize);
2136	if (ret)
2137		return ret;
2138
2139	inode_dio_wait(inode);
2140
2141	ret = gfs2_qa_get(ip);
2142	if (ret)
2143		goto out;
2144
2145	if (newsize >= inode->i_size) {
2146		ret = do_grow(inode, newsize);
2147		goto out;
2148	}
2149
2150	ret = do_shrink(inode, newsize);
2151out:
2152	gfs2_rs_delete(ip);
2153	gfs2_qa_put(ip);
2154	return ret;
2155}
2156
2157int gfs2_truncatei_resume(struct gfs2_inode *ip)
2158{
2159	int error;
2160	error = punch_hole(ip, i_size_read(&ip->i_inode), 0);
2161	if (!error)
2162		error = trunc_end(ip);
2163	return error;
2164}
2165
2166int gfs2_file_dealloc(struct gfs2_inode *ip)
2167{
2168	return punch_hole(ip, 0, 0);
2169}
2170
2171/**
2172 * gfs2_free_journal_extents - Free cached journal bmap info
2173 * @jd: The journal
2174 *
2175 */
2176
2177void gfs2_free_journal_extents(struct gfs2_jdesc *jd)
2178{
2179	struct gfs2_journal_extent *jext;
2180
2181	while(!list_empty(&jd->extent_list)) {
2182		jext = list_first_entry(&jd->extent_list, struct gfs2_journal_extent, list);
2183		list_del(&jext->list);
2184		kfree(jext);
2185	}
2186}
2187
2188/**
2189 * gfs2_add_jextent - Add or merge a new extent to extent cache
2190 * @jd: The journal descriptor
2191 * @lblock: The logical block at start of new extent
2192 * @dblock: The physical block at start of new extent
2193 * @blocks: Size of extent in fs blocks
2194 *
2195 * Returns: 0 on success or -ENOMEM
2196 */
2197
2198static int gfs2_add_jextent(struct gfs2_jdesc *jd, u64 lblock, u64 dblock, u64 blocks)
2199{
2200	struct gfs2_journal_extent *jext;
2201
2202	if (!list_empty(&jd->extent_list)) {
2203		jext = list_last_entry(&jd->extent_list, struct gfs2_journal_extent, list);
2204		if ((jext->dblock + jext->blocks) == dblock) {
2205			jext->blocks += blocks;
2206			return 0;
2207		}
2208	}
2209
2210	jext = kzalloc(sizeof(struct gfs2_journal_extent), GFP_NOFS);
2211	if (jext == NULL)
2212		return -ENOMEM;
2213	jext->dblock = dblock;
2214	jext->lblock = lblock;
2215	jext->blocks = blocks;
2216	list_add_tail(&jext->list, &jd->extent_list);
2217	jd->nr_extents++;
2218	return 0;
2219}
2220
2221/**
2222 * gfs2_map_journal_extents - Cache journal bmap info
2223 * @sdp: The super block
2224 * @jd: The journal to map
2225 *
2226 * Create a reusable "extent" mapping from all logical
2227 * blocks to all physical blocks for the given journal.  This will save
2228 * us time when writing journal blocks.  Most journals will have only one
2229 * extent that maps all their logical blocks.  That's because gfs2.mkfs
2230 * arranges the journal blocks sequentially to maximize performance.
2231 * So the extent would map the first block for the entire file length.
2232 * However, gfs2_jadd can happen while file activity is happening, so
2233 * those journals may not be sequential.  Less likely is the case where
2234 * the users created their own journals by mounting the metafs and
2235 * laying it out.  But it's still possible.  These journals might have
2236 * several extents.
2237 *
2238 * Returns: 0 on success, or error on failure
2239 */
2240
2241int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
2242{
2243	u64 lblock = 0;
2244	u64 lblock_stop;
2245	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
2246	struct buffer_head bh;
2247	unsigned int shift = sdp->sd_sb.sb_bsize_shift;
2248	u64 size;
2249	int rc;
2250	ktime_t start, end;
2251
2252	start = ktime_get();
2253	lblock_stop = i_size_read(jd->jd_inode) >> shift;
2254	size = (lblock_stop - lblock) << shift;
2255	jd->nr_extents = 0;
2256	WARN_ON(!list_empty(&jd->extent_list));
2257
2258	do {
2259		bh.b_state = 0;
2260		bh.b_blocknr = 0;
2261		bh.b_size = size;
2262		rc = gfs2_block_map(jd->jd_inode, lblock, &bh, 0);
2263		if (rc || !buffer_mapped(&bh))
2264			goto fail;
2265		rc = gfs2_add_jextent(jd, lblock, bh.b_blocknr, bh.b_size >> shift);
2266		if (rc)
2267			goto fail;
2268		size -= bh.b_size;
2269		lblock += (bh.b_size >> ip->i_inode.i_blkbits);
2270	} while(size > 0);
2271
2272	end = ktime_get();
2273	fs_info(sdp, "journal %d mapped with %u extents in %lldms\n", jd->jd_jid,
2274		jd->nr_extents, ktime_ms_delta(end, start));
2275	return 0;
2276
2277fail:
2278	fs_warn(sdp, "error %d mapping journal %u at offset %llu (extent %u)\n",
2279		rc, jd->jd_jid,
2280		(unsigned long long)(i_size_read(jd->jd_inode) - size),
2281		jd->nr_extents);
2282	fs_warn(sdp, "bmap=%d lblock=%llu block=%llu, state=0x%08lx, size=%llu\n",
2283		rc, (unsigned long long)lblock, (unsigned long long)bh.b_blocknr,
2284		bh.b_state, (unsigned long long)bh.b_size);
2285	gfs2_free_journal_extents(jd);
2286	return rc;
2287}
2288
2289/**
2290 * gfs2_write_alloc_required - figure out if a write will require an allocation
2291 * @ip: the file being written to
2292 * @offset: the offset to write to
2293 * @len: the number of bytes being written
2294 *
2295 * Returns: 1 if an alloc is required, 0 otherwise
2296 */
2297
2298int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
2299			      unsigned int len)
2300{
2301	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
2302	struct buffer_head bh;
2303	unsigned int shift;
2304	u64 lblock, lblock_stop, size;
2305	u64 end_of_file;
2306
2307	if (!len)
2308		return 0;
2309
2310	if (gfs2_is_stuffed(ip)) {
2311		if (offset + len > gfs2_max_stuffed_size(ip))
 
2312			return 1;
2313		return 0;
2314	}
2315
2316	shift = sdp->sd_sb.sb_bsize_shift;
2317	BUG_ON(gfs2_is_dir(ip));
2318	end_of_file = (i_size_read(&ip->i_inode) + sdp->sd_sb.sb_bsize - 1) >> shift;
2319	lblock = offset >> shift;
2320	lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift;
2321	if (lblock_stop > end_of_file && ip != GFS2_I(sdp->sd_rindex))
2322		return 1;
2323
2324	size = (lblock_stop - lblock) << shift;
2325	do {
2326		bh.b_state = 0;
2327		bh.b_size = size;
2328		gfs2_block_map(&ip->i_inode, lblock, &bh, 0);
2329		if (!buffer_mapped(&bh))
2330			return 1;
2331		size -= bh.b_size;
2332		lblock += (bh.b_size >> ip->i_inode.i_blkbits);
2333	} while(size > 0);
2334
2335	return 0;
2336}
2337
2338static int stuffed_zero_range(struct inode *inode, loff_t offset, loff_t length)
2339{
2340	struct gfs2_inode *ip = GFS2_I(inode);
2341	struct buffer_head *dibh;
2342	int error;
2343
2344	if (offset >= inode->i_size)
2345		return 0;
2346	if (offset + length > inode->i_size)
2347		length = inode->i_size - offset;
2348
2349	error = gfs2_meta_inode_buffer(ip, &dibh);
2350	if (error)
2351		return error;
2352	gfs2_trans_add_meta(ip->i_gl, dibh);
2353	memset(dibh->b_data + sizeof(struct gfs2_dinode) + offset, 0,
2354	       length);
2355	brelse(dibh);
2356	return 0;
2357}
2358
2359static int gfs2_journaled_truncate_range(struct inode *inode, loff_t offset,
2360					 loff_t length)
2361{
2362	struct gfs2_sbd *sdp = GFS2_SB(inode);
2363	loff_t max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize;
2364	int error;
2365
2366	while (length) {
2367		struct gfs2_trans *tr;
2368		loff_t chunk;
2369		unsigned int offs;
2370
2371		chunk = length;
2372		if (chunk > max_chunk)
2373			chunk = max_chunk;
2374
2375		offs = offset & ~PAGE_MASK;
2376		if (offs && chunk > PAGE_SIZE)
2377			chunk = offs + ((chunk - offs) & PAGE_MASK);
2378
2379		truncate_pagecache_range(inode, offset, chunk);
2380		offset += chunk;
2381		length -= chunk;
2382
2383		tr = current->journal_info;
2384		if (!test_bit(TR_TOUCHED, &tr->tr_flags))
2385			continue;
2386
2387		gfs2_trans_end(sdp);
2388		error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES);
2389		if (error)
2390			return error;
2391	}
2392	return 0;
2393}
2394
2395int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length)
2396{
2397	struct inode *inode = file_inode(file);
2398	struct gfs2_inode *ip = GFS2_I(inode);
2399	struct gfs2_sbd *sdp = GFS2_SB(inode);
2400	unsigned int blocksize = i_blocksize(inode);
2401	loff_t start, end;
2402	int error;
2403
2404	if (!gfs2_is_stuffed(ip)) {
2405		unsigned int start_off, end_len;
2406
2407		start_off = offset & (blocksize - 1);
2408		end_len = (offset + length) & (blocksize - 1);
2409		if (start_off) {
2410			unsigned int len = length;
2411			if (length > blocksize - start_off)
2412				len = blocksize - start_off;
2413			error = gfs2_block_zero_range(inode, offset, len);
2414			if (error)
2415				goto out;
2416			if (start_off + length < blocksize)
2417				end_len = 0;
2418		}
2419		if (end_len) {
2420			error = gfs2_block_zero_range(inode,
2421				offset + length - end_len, end_len);
2422			if (error)
2423				goto out;
2424		}
2425	}
2426
2427	start = round_down(offset, blocksize);
2428	end = round_up(offset + length, blocksize) - 1;
2429	error = filemap_write_and_wait_range(inode->i_mapping, start, end);
2430	if (error)
2431		return error;
2432
2433	if (gfs2_is_jdata(ip))
2434		error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_JDATA,
2435					 GFS2_JTRUNC_REVOKES);
2436	else
2437		error = gfs2_trans_begin(sdp, RES_DINODE, 0);
2438	if (error)
2439		return error;
2440
2441	if (gfs2_is_stuffed(ip)) {
2442		error = stuffed_zero_range(inode, offset, length);
2443		if (error)
2444			goto out;
2445	}
2446
2447	if (gfs2_is_jdata(ip)) {
2448		BUG_ON(!current->journal_info);
2449		gfs2_journaled_truncate_range(inode, offset, length);
2450	} else
2451		truncate_pagecache_range(inode, offset, offset + length - 1);
2452
2453	file_update_time(file);
2454	mark_inode_dirty(inode);
2455
2456	if (current->journal_info)
2457		gfs2_trans_end(sdp);
2458
2459	if (!gfs2_is_stuffed(ip))
2460		error = punch_hole(ip, offset, length);
2461
2462out:
2463	if (current->journal_info)
2464		gfs2_trans_end(sdp);
2465	return error;
2466}
2467
2468static int gfs2_map_blocks(struct iomap_writepage_ctx *wpc, struct inode *inode,
2469		loff_t offset, unsigned int len)
2470{
2471	int ret;
2472
2473	if (WARN_ON_ONCE(gfs2_is_stuffed(GFS2_I(inode))))
2474		return -EIO;
2475
2476	if (offset >= wpc->iomap.offset &&
2477	    offset < wpc->iomap.offset + wpc->iomap.length)
2478		return 0;
2479
2480	memset(&wpc->iomap, 0, sizeof(wpc->iomap));
2481	ret = gfs2_iomap_get(inode, offset, INT_MAX, &wpc->iomap);
2482	return ret;
2483}
2484
2485const struct iomap_writeback_ops gfs2_writeback_ops = {
2486	.map_blocks		= gfs2_map_blocks,
2487};