1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Simple file system for zoned block devices exposing zones as files.
   4 *
   5 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
   6 */
   7#include <linux/module.h>
   8#include <linux/pagemap.h>
   9#include <linux/magic.h>
  10#include <linux/iomap.h>
  11#include <linux/init.h>
  12#include <linux/slab.h>
  13#include <linux/blkdev.h>
  14#include <linux/statfs.h>
  15#include <linux/writeback.h>
  16#include <linux/quotaops.h>
  17#include <linux/seq_file.h>
  18#include <linux/parser.h>
  19#include <linux/uio.h>
  20#include <linux/mman.h>
  21#include <linux/sched/mm.h>
  22#include <linux/crc32.h>
  23#include <linux/task_io_accounting_ops.h>
  24
  25#include "zonefs.h"
  26
  27#define CREATE_TRACE_POINTS
  28#include "trace.h"
  29
  30/*
  31 * Manage the active zone count. Called with zi->i_truncate_mutex held.
  32 */
  33static void zonefs_account_active(struct inode *inode)
  34{
  35	struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
  36	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 
 
 
 
 
 
 
 
  37
  38	lockdep_assert_held(&zi->i_truncate_mutex);
 
 
 
 
 
 
  39
  40	if (zi->i_ztype != ZONEFS_ZTYPE_SEQ)
  41		return;
  42
  43	/*
  44	 * For zones that transitioned to the offline or readonly condition,
  45	 * we only need to clear the active state.
  46	 */
  47	if (zi->i_flags & (ZONEFS_ZONE_OFFLINE | ZONEFS_ZONE_READONLY))
  48		goto out;
  49
  50	/*
  51	 * If the zone is active, that is, if it is explicitly open or
  52	 * partially written, check if it was already accounted as active.
  53	 */
  54	if ((zi->i_flags & ZONEFS_ZONE_OPEN) ||
  55	    (zi->i_wpoffset > 0 && zi->i_wpoffset < zi->i_max_size)) {
  56		if (!(zi->i_flags & ZONEFS_ZONE_ACTIVE)) {
  57			zi->i_flags |= ZONEFS_ZONE_ACTIVE;
  58			atomic_inc(&sbi->s_active_seq_files);
  59		}
  60		return;
  61	}
  62
  63out:
  64	/* The zone is not active. If it was, update the active count */
  65	if (zi->i_flags & ZONEFS_ZONE_ACTIVE) {
  66		zi->i_flags &= ~ZONEFS_ZONE_ACTIVE;
  67		atomic_dec(&sbi->s_active_seq_files);
  68	}
  69}
  70
  71static inline int zonefs_zone_mgmt(struct inode *inode, enum req_op op)
 
 
 
  72{
  73	struct zonefs_inode_info *zi = ZONEFS_I(inode);
  74	int ret;
  75
  76	lockdep_assert_held(&zi->i_truncate_mutex);
 
 
 
 
 
 
 
 
 
  77
  78	/*
  79	 * With ZNS drives, closing an explicitly open zone that has not been
  80	 * written will change the zone state to "closed", that is, the zone
  81	 * will remain active. Since this can then cause failure of explicit
  82	 * open operation on other zones if the drive active zone resources
  83	 * are exceeded, make sure that the zone does not remain active by
  84	 * resetting it.
  85	 */
  86	if (op == REQ_OP_ZONE_CLOSE && !zi->i_wpoffset)
  87		op = REQ_OP_ZONE_RESET;
  88
  89	trace_zonefs_zone_mgmt(inode, op);
  90	ret = blkdev_zone_mgmt(inode->i_sb->s_bdev, op, zi->i_zsector,
  91			       zi->i_zone_size >> SECTOR_SHIFT, GFP_NOFS);
  92	if (ret) {
  93		zonefs_err(inode->i_sb,
  94			   "Zone management operation %s at %llu failed %d\n",
  95			   blk_op_str(op), zi->i_zsector, ret);
  96		return ret;
  97	}
  98
  99	return 0;
 100}
 101
 102static inline void zonefs_i_size_write(struct inode *inode, loff_t isize)
 103{
 104	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 105
 106	i_size_write(inode, isize);
 107	/*
 108	 * A full zone is no longer open/active and does not need
 109	 * explicit closing.
 110	 */
 111	if (isize >= zi->i_max_size) {
 112		struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
 113
 114		if (zi->i_flags & ZONEFS_ZONE_ACTIVE)
 115			atomic_dec(&sbi->s_active_seq_files);
 116		zi->i_flags &= ~(ZONEFS_ZONE_OPEN | ZONEFS_ZONE_ACTIVE);
 117	}
 118}
 119
 120static int zonefs_read_iomap_begin(struct inode *inode, loff_t offset,
 121				   loff_t length, unsigned int flags,
 122				   struct iomap *iomap, struct iomap *srcmap)
 123{
 124	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 125	struct super_block *sb = inode->i_sb;
 126	loff_t isize;
 127
 128	/*
 129	 * All blocks are always mapped below EOF. If reading past EOF,
 130	 * act as if there is a hole up to the file maximum size.
 131	 */
 132	mutex_lock(&zi->i_truncate_mutex);
 133	iomap->bdev = inode->i_sb->s_bdev;
 134	iomap->offset = ALIGN_DOWN(offset, sb->s_blocksize);
 135	isize = i_size_read(inode);
 136	if (iomap->offset >= isize) {
 137		iomap->type = IOMAP_HOLE;
 138		iomap->addr = IOMAP_NULL_ADDR;
 139		iomap->length = length;
 140	} else {
 141		iomap->type = IOMAP_MAPPED;
 142		iomap->addr = (zi->i_zsector << SECTOR_SHIFT) + iomap->offset;
 143		iomap->length = isize - iomap->offset;
 144	}
 145	mutex_unlock(&zi->i_truncate_mutex);
 146
 147	trace_zonefs_iomap_begin(inode, iomap);
 148
 149	return 0;
 150}
 151
 152static const struct iomap_ops zonefs_read_iomap_ops = {
 153	.iomap_begin	= zonefs_read_iomap_begin,
 154};
 155
 156static int zonefs_write_iomap_begin(struct inode *inode, loff_t offset,
 157				    loff_t length, unsigned int flags,
 158				    struct iomap *iomap, struct iomap *srcmap)
 159{
 160	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 161	struct super_block *sb = inode->i_sb;
 162	loff_t isize;
 163
 164	/* All write I/Os should always be within the file maximum size */
 165	if (WARN_ON_ONCE(offset + length > zi->i_max_size))
 166		return -EIO;
 167
 168	/*
 169	 * Sequential zones can only accept direct writes. This is already
 170	 * checked when writes are issued, so warn if we see a page writeback
 171	 * operation.
 172	 */
 173	if (WARN_ON_ONCE(zi->i_ztype == ZONEFS_ZTYPE_SEQ &&
 174			 !(flags & IOMAP_DIRECT)))
 175		return -EIO;
 176
 177	/*
 178	 * For conventional zones, all blocks are always mapped. For sequential
 179	 * zones, all blocks after always mapped below the inode size (zone
 180	 * write pointer) and unwriten beyond.
 181	 */
 182	mutex_lock(&zi->i_truncate_mutex);
 183	iomap->bdev = inode->i_sb->s_bdev;
 184	iomap->offset = ALIGN_DOWN(offset, sb->s_blocksize);
 185	iomap->addr = (zi->i_zsector << SECTOR_SHIFT) + iomap->offset;
 186	isize = i_size_read(inode);
 187	if (iomap->offset >= isize) {
 188		iomap->type = IOMAP_UNWRITTEN;
 189		iomap->length = zi->i_max_size - iomap->offset;
 190	} else {
 191		iomap->type = IOMAP_MAPPED;
 192		iomap->length = isize - iomap->offset;
 193	}
 194	mutex_unlock(&zi->i_truncate_mutex);
 195
 196	trace_zonefs_iomap_begin(inode, iomap);
 197
 198	return 0;
 199}
 200
 201static const struct iomap_ops zonefs_write_iomap_ops = {
 202	.iomap_begin	= zonefs_write_iomap_begin,
 203};
 204
 205static int zonefs_read_folio(struct file *unused, struct folio *folio)
 206{
 207	return iomap_read_folio(folio, &zonefs_read_iomap_ops);
 208}
 209
 210static void zonefs_readahead(struct readahead_control *rac)
 211{
 212	iomap_readahead(rac, &zonefs_read_iomap_ops);
 213}
 214
 215/*
 216 * Map blocks for page writeback. This is used only on conventional zone files,
 217 * which implies that the page range can only be within the fixed inode size.
 218 */
 219static int zonefs_write_map_blocks(struct iomap_writepage_ctx *wpc,
 220				   struct inode *inode, loff_t offset)
 221{
 222	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 223
 224	if (WARN_ON_ONCE(zi->i_ztype != ZONEFS_ZTYPE_CNV))
 225		return -EIO;
 226	if (WARN_ON_ONCE(offset >= i_size_read(inode)))
 227		return -EIO;
 228
 229	/* If the mapping is already OK, nothing needs to be done */
 230	if (offset >= wpc->iomap.offset &&
 231	    offset < wpc->iomap.offset + wpc->iomap.length)
 232		return 0;
 233
 234	return zonefs_write_iomap_begin(inode, offset, zi->i_max_size - offset,
 235					IOMAP_WRITE, &wpc->iomap, NULL);
 236}
 237
 238static const struct iomap_writeback_ops zonefs_writeback_ops = {
 239	.map_blocks		= zonefs_write_map_blocks,
 240};
 241
 242static int zonefs_writepages(struct address_space *mapping,
 243			     struct writeback_control *wbc)
 244{
 245	struct iomap_writepage_ctx wpc = { };
 246
 247	return iomap_writepages(mapping, wbc, &wpc, &zonefs_writeback_ops);
 248}
 249
 250static int zonefs_swap_activate(struct swap_info_struct *sis,
 251				struct file *swap_file, sector_t *span)
 252{
 253	struct inode *inode = file_inode(swap_file);
 254	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 255
 256	if (zi->i_ztype != ZONEFS_ZTYPE_CNV) {
 257		zonefs_err(inode->i_sb,
 258			   "swap file: not a conventional zone file\n");
 259		return -EINVAL;
 260	}
 261
 262	return iomap_swapfile_activate(sis, swap_file, span,
 263				       &zonefs_read_iomap_ops);
 264}
 265
 266static const struct address_space_operations zonefs_file_aops = {
 267	.read_folio		= zonefs_read_folio,
 268	.readahead		= zonefs_readahead,
 269	.writepages		= zonefs_writepages,
 270	.dirty_folio		= filemap_dirty_folio,
 271	.release_folio		= iomap_release_folio,
 272	.invalidate_folio	= iomap_invalidate_folio,
 273	.migrate_folio		= filemap_migrate_folio,
 274	.is_partially_uptodate	= iomap_is_partially_uptodate,
 275	.error_remove_page	= generic_error_remove_page,
 276	.direct_IO		= noop_direct_IO,
 277	.swap_activate		= zonefs_swap_activate,
 278};
 279
 280static void zonefs_update_stats(struct inode *inode, loff_t new_isize)
 281{
 282	struct super_block *sb = inode->i_sb;
 283	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
 284	loff_t old_isize = i_size_read(inode);
 285	loff_t nr_blocks;
 286
 287	if (new_isize == old_isize)
 288		return;
 289
 290	spin_lock(&sbi->s_lock);
 291
 292	/*
 293	 * This may be called for an update after an IO error.
 294	 * So beware of the values seen.
 295	 */
 296	if (new_isize < old_isize) {
 297		nr_blocks = (old_isize - new_isize) >> sb->s_blocksize_bits;
 298		if (sbi->s_used_blocks > nr_blocks)
 299			sbi->s_used_blocks -= nr_blocks;
 300		else
 301			sbi->s_used_blocks = 0;
 302	} else {
 303		sbi->s_used_blocks +=
 304			(new_isize - old_isize) >> sb->s_blocksize_bits;
 305		if (sbi->s_used_blocks > sbi->s_blocks)
 306			sbi->s_used_blocks = sbi->s_blocks;
 307	}
 308
 309	spin_unlock(&sbi->s_lock);
 310}
 311
 312/*
 313 * Check a zone condition and adjust its file inode access permissions for
 314 * offline and readonly zones. Return the inode size corresponding to the
 315 * amount of readable data in the zone.
 316 */
 317static loff_t zonefs_check_zone_condition(struct inode *inode,
 318					  struct blk_zone *zone, bool warn,
 319					  bool mount)
 320{
 321	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 322
 323	switch (zone->cond) {
 324	case BLK_ZONE_COND_OFFLINE:
 325		/*
 326		 * Dead zone: make the inode immutable, disable all accesses
 327		 * and set the file size to 0 (zone wp set to zone start).
 328		 */
 329		if (warn)
 330			zonefs_warn(inode->i_sb, "inode %lu: offline zone\n",
 331				    inode->i_ino);
 332		inode->i_flags |= S_IMMUTABLE;
 333		inode->i_mode &= ~0777;
 334		zone->wp = zone->start;
 335		zi->i_flags |= ZONEFS_ZONE_OFFLINE;
 336		return 0;
 337	case BLK_ZONE_COND_READONLY:
 338		/*
 339		 * The write pointer of read-only zones is invalid. If such a
 340		 * zone is found during mount, the file size cannot be retrieved
 341		 * so we treat the zone as offline (mount == true case).
 342		 * Otherwise, keep the file size as it was when last updated
 343		 * so that the user can recover data. In both cases, writes are
 344		 * always disabled for the zone.
 345		 */
 346		if (warn)
 347			zonefs_warn(inode->i_sb, "inode %lu: read-only zone\n",
 348				    inode->i_ino);
 349		inode->i_flags |= S_IMMUTABLE;
 350		if (mount) {
 351			zone->cond = BLK_ZONE_COND_OFFLINE;
 352			inode->i_mode &= ~0777;
 353			zone->wp = zone->start;
 354			zi->i_flags |= ZONEFS_ZONE_OFFLINE;
 355			return 0;
 356		}
 357		zi->i_flags |= ZONEFS_ZONE_READONLY;
 358		inode->i_mode &= ~0222;
 359		return i_size_read(inode);
 360	case BLK_ZONE_COND_FULL:
 361		/* The write pointer of full zones is invalid. */
 362		return zi->i_max_size;
 363	default:
 364		if (zi->i_ztype == ZONEFS_ZTYPE_CNV)
 365			return zi->i_max_size;
 366		return (zone->wp - zone->start) << SECTOR_SHIFT;
 367	}
 368}
 369
 370struct zonefs_ioerr_data {
 371	struct inode	*inode;
 372	bool		write;
 373};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 374
 375static int zonefs_io_error_cb(struct blk_zone *zone, unsigned int idx,
 376			      void *data)
 377{
 378	struct zonefs_ioerr_data *err = data;
 379	struct inode *inode = err->inode;
 380	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 
 
 
 
 
 
 
 381	struct super_block *sb = inode->i_sb;
 382	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
 383	loff_t isize, data_size;
 384
 385	/*
 386	 * Check the zone condition: if the zone is not "bad" (offline or
 387	 * read-only), read errors are simply signaled to the IO issuer as long
 388	 * as there is no inconsistency between the inode size and the amount of
 389	 * data writen in the zone (data_size).
 390	 */
 391	data_size = zonefs_check_zone_condition(inode, zone, true, false);
 392	isize = i_size_read(inode);
 393	if (zone->cond != BLK_ZONE_COND_OFFLINE &&
 394	    zone->cond != BLK_ZONE_COND_READONLY &&
 395	    !err->write && isize == data_size)
 396		return 0;
 397
 398	/*
 399	 * At this point, we detected either a bad zone or an inconsistency
 400	 * between the inode size and the amount of data written in the zone.
 401	 * For the latter case, the cause may be a write IO error or an external
 402	 * action on the device. Two error patterns exist:
 403	 * 1) The inode size is lower than the amount of data in the zone:
 404	 *    a write operation partially failed and data was writen at the end
 405	 *    of the file. This can happen in the case of a large direct IO
 406	 *    needing several BIOs and/or write requests to be processed.
 407	 * 2) The inode size is larger than the amount of data in the zone:
 408	 *    this can happen with a deferred write error with the use of the
 409	 *    device side write cache after getting successful write IO
 410	 *    completions. Other possibilities are (a) an external corruption,
 411	 *    e.g. an application reset the zone directly, or (b) the device
 412	 *    has a serious problem (e.g. firmware bug).
 413	 *
 414	 * In all cases, warn about inode size inconsistency and handle the
 415	 * IO error according to the zone condition and to the mount options.
 416	 */
 417	if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && isize != data_size)
 418		zonefs_warn(sb, "inode %lu: invalid size %lld (should be %lld)\n",
 
 419			    inode->i_ino, isize, data_size);
 420
 421	/*
 422	 * First handle bad zones signaled by hardware. The mount options
 423	 * errors=zone-ro and errors=zone-offline result in changing the
 424	 * zone condition to read-only and offline respectively, as if the
 425	 * condition was signaled by the hardware.
 426	 */
 427	if (zone->cond == BLK_ZONE_COND_OFFLINE ||
 428	    sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL) {
 429		zonefs_warn(sb, "inode %lu: read/write access disabled\n",
 430			    inode->i_ino);
 431		if (zone->cond != BLK_ZONE_COND_OFFLINE) {
 432			zone->cond = BLK_ZONE_COND_OFFLINE;
 433			data_size = zonefs_check_zone_condition(inode, zone,
 434								false, false);
 435		}
 436	} else if (zone->cond == BLK_ZONE_COND_READONLY ||
 437		   sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO) {
 438		zonefs_warn(sb, "inode %lu: write access disabled\n",
 439			    inode->i_ino);
 440		if (zone->cond != BLK_ZONE_COND_READONLY) {
 441			zone->cond = BLK_ZONE_COND_READONLY;
 442			data_size = zonefs_check_zone_condition(inode, zone,
 443								false, false);
 444		}
 445	} else if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO &&
 446		   data_size > isize) {
 447		/* Do not expose garbage data */
 448		data_size = isize;
 449	}
 450
 451	/*
 452	 * If the filesystem is mounted with the explicit-open mount option, we
 453	 * need to clear the ZONEFS_ZONE_OPEN flag if the zone transitioned to
 454	 * the read-only or offline condition, to avoid attempting an explicit
 455	 * close of the zone when the inode file is closed.
 456	 */
 457	if ((sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) &&
 458	    (zone->cond == BLK_ZONE_COND_OFFLINE ||
 459	     zone->cond == BLK_ZONE_COND_READONLY))
 460		zi->i_flags &= ~ZONEFS_ZONE_OPEN;
 461
 462	/*
 463	 * If error=remount-ro was specified, any error result in remounting
 464	 * the volume as read-only.
 465	 */
 466	if ((sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO) && !sb_rdonly(sb)) {
 467		zonefs_warn(sb, "remounting filesystem read-only\n");
 468		sb->s_flags |= SB_RDONLY;
 469	}
 470
 471	/*
 472	 * Update block usage stats and the inode size  to prevent access to
 473	 * invalid data.
 474	 */
 475	zonefs_update_stats(inode, data_size);
 476	zonefs_i_size_write(inode, data_size);
 477	zi->i_wpoffset = data_size;
 478	zonefs_account_active(inode);
 479
 480	return 0;
 481}
 482
 483/*
 484 * When an file IO error occurs, check the file zone to see if there is a change
 485 * in the zone condition (e.g. offline or read-only). For a failed write to a
 486 * sequential zone, the zone write pointer position must also be checked to
 487 * eventually correct the file size and zonefs inode write pointer offset
 488 * (which can be out of sync with the drive due to partial write failures).
 489 */
 490static void __zonefs_io_error(struct inode *inode, bool write)
 491{
 492	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 493	struct super_block *sb = inode->i_sb;
 494	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
 495	unsigned int noio_flag;
 496	unsigned int nr_zones = 1;
 497	struct zonefs_ioerr_data err = {
 498		.inode = inode,
 499		.write = write,
 500	};
 501	int ret;
 502
 503	/*
 504	 * The only files that have more than one zone are conventional zone
 505	 * files with aggregated conventional zones, for which the inode zone
 506	 * size is always larger than the device zone size.
 507	 */
 508	if (zi->i_zone_size > bdev_zone_sectors(sb->s_bdev))
 509		nr_zones = zi->i_zone_size >>
 510			(sbi->s_zone_sectors_shift + SECTOR_SHIFT);
 
 
 
 
 
 
 
 511
 512	/*
 513	 * Memory allocations in blkdev_report_zones() can trigger a memory
 514	 * reclaim which may in turn cause a recursion into zonefs as well as
 515	 * struct request allocations for the same device. The former case may
 516	 * end up in a deadlock on the inode truncate mutex, while the latter
 517	 * may prevent IO forward progress. Executing the report zones under
 518	 * the GFP_NOIO context avoids both problems.
 519	 */
 520	noio_flag = memalloc_noio_save();
 521	ret = blkdev_report_zones(sb->s_bdev, zi->i_zsector, nr_zones,
 522				  zonefs_io_error_cb, &err);
 523	if (ret != nr_zones)
 524		zonefs_err(sb, "Get inode %lu zone information failed %d\n",
 525			   inode->i_ino, ret);
 526	memalloc_noio_restore(noio_flag);
 527}
 528
 529static void zonefs_io_error(struct inode *inode, bool write)
 530{
 531	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 532
 533	mutex_lock(&zi->i_truncate_mutex);
 534	__zonefs_io_error(inode, write);
 535	mutex_unlock(&zi->i_truncate_mutex);
 536}
 537
 538static int zonefs_file_truncate(struct inode *inode, loff_t isize)
 539{
 540	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 541	loff_t old_isize;
 542	enum req_op op;
 543	int ret = 0;
 544
 545	/*
 546	 * Only sequential zone files can be truncated and truncation is allowed
 547	 * only down to a 0 size, which is equivalent to a zone reset, and to
 548	 * the maximum file size, which is equivalent to a zone finish.
 549	 */
 550	if (zi->i_ztype != ZONEFS_ZTYPE_SEQ)
 551		return -EPERM;
 552
 553	if (!isize)
 554		op = REQ_OP_ZONE_RESET;
 555	else if (isize == zi->i_max_size)
 556		op = REQ_OP_ZONE_FINISH;
 557	else
 558		return -EPERM;
 559
 560	inode_dio_wait(inode);
 561
 562	/* Serialize against page faults */
 563	filemap_invalidate_lock(inode->i_mapping);
 564
 565	/* Serialize against zonefs_iomap_begin() */
 566	mutex_lock(&zi->i_truncate_mutex);
 567
 568	old_isize = i_size_read(inode);
 569	if (isize == old_isize)
 570		goto unlock;
 571
 572	ret = zonefs_zone_mgmt(inode, op);
 573	if (ret)
 574		goto unlock;
 575
 576	/*
 577	 * If the mount option ZONEFS_MNTOPT_EXPLICIT_OPEN is set,
 578	 * take care of open zones.
 579	 */
 580	if (zi->i_flags & ZONEFS_ZONE_OPEN) {
 581		/*
 582		 * Truncating a zone to EMPTY or FULL is the equivalent of
 583		 * closing the zone. For a truncation to 0, we need to
 584		 * re-open the zone to ensure new writes can be processed.
 585		 * For a truncation to the maximum file size, the zone is
 586		 * closed and writes cannot be accepted anymore, so clear
 587		 * the open flag.
 588		 */
 589		if (!isize)
 590			ret = zonefs_zone_mgmt(inode, REQ_OP_ZONE_OPEN);
 591		else
 592			zi->i_flags &= ~ZONEFS_ZONE_OPEN;
 593	}
 594
 595	zonefs_update_stats(inode, isize);
 596	truncate_setsize(inode, isize);
 597	zi->i_wpoffset = isize;
 598	zonefs_account_active(inode);
 599
 600unlock:
 601	mutex_unlock(&zi->i_truncate_mutex);
 602	filemap_invalidate_unlock(inode->i_mapping);
 603
 604	return ret;
 605}
 606
 607static int zonefs_inode_setattr(struct user_namespace *mnt_userns,
 608				struct dentry *dentry, struct iattr *iattr)
 609{
 610	struct inode *inode = d_inode(dentry);
 611	int ret;
 612
 613	if (unlikely(IS_IMMUTABLE(inode)))
 614		return -EPERM;
 615
 616	ret = setattr_prepare(&init_user_ns, dentry, iattr);
 617	if (ret)
 618		return ret;
 619
 620	/*
 621	 * Since files and directories cannot be created nor deleted, do not
 622	 * allow setting any write attributes on the sub-directories grouping
 623	 * files by zone type.
 624	 */
 625	if ((iattr->ia_valid & ATTR_MODE) && S_ISDIR(inode->i_mode) &&
 626	    (iattr->ia_mode & 0222))
 627		return -EPERM;
 628
 629	if (((iattr->ia_valid & ATTR_UID) &&
 630	     !uid_eq(iattr->ia_uid, inode->i_uid)) ||
 631	    ((iattr->ia_valid & ATTR_GID) &&
 632	     !gid_eq(iattr->ia_gid, inode->i_gid))) {
 633		ret = dquot_transfer(mnt_userns, inode, iattr);
 634		if (ret)
 635			return ret;
 636	}
 637
 638	if (iattr->ia_valid & ATTR_SIZE) {
 639		ret = zonefs_file_truncate(inode, iattr->ia_size);
 640		if (ret)
 641			return ret;
 642	}
 643
 644	setattr_copy(&init_user_ns, inode, iattr);
 645
 646	return 0;
 647}
 648
 649static const struct inode_operations zonefs_file_inode_operations = {
 650	.setattr	= zonefs_inode_setattr,
 651};
 652
 653static int zonefs_file_fsync(struct file *file, loff_t start, loff_t end,
 654			     int datasync)
 655{
 656	struct inode *inode = file_inode(file);
 657	int ret = 0;
 658
 659	if (unlikely(IS_IMMUTABLE(inode)))
 660		return -EPERM;
 661
 662	/*
 663	 * Since only direct writes are allowed in sequential files, page cache
 664	 * flush is needed only for conventional zone files.
 665	 */
 666	if (ZONEFS_I(inode)->i_ztype == ZONEFS_ZTYPE_CNV)
 667		ret = file_write_and_wait_range(file, start, end);
 668	if (!ret)
 669		ret = blkdev_issue_flush(inode->i_sb->s_bdev);
 670
 671	if (ret)
 672		zonefs_io_error(inode, true);
 673
 674	return ret;
 675}
 676
 677static vm_fault_t zonefs_filemap_page_mkwrite(struct vm_fault *vmf)
 678{
 679	struct inode *inode = file_inode(vmf->vma->vm_file);
 680	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 681	vm_fault_t ret;
 682
 683	if (unlikely(IS_IMMUTABLE(inode)))
 684		return VM_FAULT_SIGBUS;
 685
 686	/*
 687	 * Sanity check: only conventional zone files can have shared
 688	 * writeable mappings.
 689	 */
 690	if (WARN_ON_ONCE(zi->i_ztype != ZONEFS_ZTYPE_CNV))
 691		return VM_FAULT_NOPAGE;
 692
 693	sb_start_pagefault(inode->i_sb);
 694	file_update_time(vmf->vma->vm_file);
 695
 696	/* Serialize against truncates */
 697	filemap_invalidate_lock_shared(inode->i_mapping);
 698	ret = iomap_page_mkwrite(vmf, &zonefs_write_iomap_ops);
 699	filemap_invalidate_unlock_shared(inode->i_mapping);
 700
 701	sb_end_pagefault(inode->i_sb);
 702	return ret;
 703}
 704
 705static const struct vm_operations_struct zonefs_file_vm_ops = {
 706	.fault		= filemap_fault,
 707	.map_pages	= filemap_map_pages,
 708	.page_mkwrite	= zonefs_filemap_page_mkwrite,
 709};
 710
 711static int zonefs_file_mmap(struct file *file, struct vm_area_struct *vma)
 712{
 713	/*
 714	 * Conventional zones accept random writes, so their files can support
 715	 * shared writable mappings. For sequential zone files, only read
 716	 * mappings are possible since there are no guarantees for write
 717	 * ordering between msync() and page cache writeback.
 718	 */
 719	if (ZONEFS_I(file_inode(file))->i_ztype == ZONEFS_ZTYPE_SEQ &&
 720	    (vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
 721		return -EINVAL;
 722
 723	file_accessed(file);
 724	vma->vm_ops = &zonefs_file_vm_ops;
 725
 726	return 0;
 727}
 728
 729static loff_t zonefs_file_llseek(struct file *file, loff_t offset, int whence)
 730{
 731	loff_t isize = i_size_read(file_inode(file));
 732
 733	/*
 734	 * Seeks are limited to below the zone size for conventional zones
 735	 * and below the zone write pointer for sequential zones. In both
 736	 * cases, this limit is the inode size.
 737	 */
 738	return generic_file_llseek_size(file, offset, whence, isize, isize);
 739}
 740
 741static int zonefs_file_write_dio_end_io(struct kiocb *iocb, ssize_t size,
 742					int error, unsigned int flags)
 743{
 744	struct inode *inode = file_inode(iocb->ki_filp);
 745	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 746
 747	if (error) {
 748		zonefs_io_error(inode, true);
 749		return error;
 750	}
 751
 752	if (size && zi->i_ztype != ZONEFS_ZTYPE_CNV) {
 753		/*
 754		 * Note that we may be seeing completions out of order,
 755		 * but that is not a problem since a write completed
 756		 * successfully necessarily means that all preceding writes
 757		 * were also successful. So we can safely increase the inode
 758		 * size to the write end location.
 759		 */
 760		mutex_lock(&zi->i_truncate_mutex);
 761		if (i_size_read(inode) < iocb->ki_pos + size) {
 762			zonefs_update_stats(inode, iocb->ki_pos + size);
 763			zonefs_i_size_write(inode, iocb->ki_pos + size);
 764		}
 765		mutex_unlock(&zi->i_truncate_mutex);
 766	}
 767
 768	return 0;
 769}
 770
 771static const struct iomap_dio_ops zonefs_write_dio_ops = {
 772	.end_io			= zonefs_file_write_dio_end_io,
 773};
 774
 775static ssize_t zonefs_file_dio_append(struct kiocb *iocb, struct iov_iter *from)
 776{
 777	struct inode *inode = file_inode(iocb->ki_filp);
 778	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 779	struct block_device *bdev = inode->i_sb->s_bdev;
 780	unsigned int max = bdev_max_zone_append_sectors(bdev);
 781	struct bio *bio;
 782	ssize_t size;
 783	int nr_pages;
 784	ssize_t ret;
 785
 786	max = ALIGN_DOWN(max << SECTOR_SHIFT, inode->i_sb->s_blocksize);
 787	iov_iter_truncate(from, max);
 788
 789	nr_pages = iov_iter_npages(from, BIO_MAX_VECS);
 790	if (!nr_pages)
 791		return 0;
 792
 793	bio = bio_alloc(bdev, nr_pages,
 794			REQ_OP_ZONE_APPEND | REQ_SYNC | REQ_IDLE, GFP_NOFS);
 795	bio->bi_iter.bi_sector = zi->i_zsector;
 796	bio->bi_ioprio = iocb->ki_ioprio;
 797	if (iocb_is_dsync(iocb))
 798		bio->bi_opf |= REQ_FUA;
 799
 800	ret = bio_iov_iter_get_pages(bio, from);
 801	if (unlikely(ret))
 802		goto out_release;
 803
 804	size = bio->bi_iter.bi_size;
 805	task_io_account_write(size);
 806
 807	if (iocb->ki_flags & IOCB_HIPRI)
 808		bio_set_polled(bio, iocb);
 809
 810	ret = submit_bio_wait(bio);
 811
 812	/*
 813	 * If the file zone was written underneath the file system, the zone
 814	 * write pointer may not be where we expect it to be, but the zone
 815	 * append write can still succeed. So check manually that we wrote where
 816	 * we intended to, that is, at zi->i_wpoffset.
 817	 */
 818	if (!ret) {
 819		sector_t wpsector =
 820			zi->i_zsector + (zi->i_wpoffset >> SECTOR_SHIFT);
 821
 822		if (bio->bi_iter.bi_sector != wpsector) {
 823			zonefs_warn(inode->i_sb,
 824				"Corrupted write pointer %llu for zone at %llu\n",
 825				wpsector, zi->i_zsector);
 826			ret = -EIO;
 827		}
 828	}
 829
 830	zonefs_file_write_dio_end_io(iocb, size, ret, 0);
 831	trace_zonefs_file_dio_append(inode, size, ret);
 832
 833out_release:
 834	bio_release_pages(bio, false);
 835	bio_put(bio);
 836
 837	if (ret >= 0) {
 838		iocb->ki_pos += size;
 839		return size;
 840	}
 841
 842	return ret;
 843}
 844
 845/*
 846 * Do not exceed the LFS limits nor the file zone size. If pos is under the
 847 * limit it becomes a short access. If it exceeds the limit, return -EFBIG.
 848 */
 849static loff_t zonefs_write_check_limits(struct file *file, loff_t pos,
 850					loff_t count)
 851{
 852	struct inode *inode = file_inode(file);
 853	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 854	loff_t limit = rlimit(RLIMIT_FSIZE);
 855	loff_t max_size = zi->i_max_size;
 856
 857	if (limit != RLIM_INFINITY) {
 858		if (pos >= limit) {
 859			send_sig(SIGXFSZ, current, 0);
 860			return -EFBIG;
 861		}
 862		count = min(count, limit - pos);
 863	}
 864
 865	if (!(file->f_flags & O_LARGEFILE))
 866		max_size = min_t(loff_t, MAX_NON_LFS, max_size);
 867
 868	if (unlikely(pos >= max_size))
 869		return -EFBIG;
 870
 871	return min(count, max_size - pos);
 872}
 873
 874static ssize_t zonefs_write_checks(struct kiocb *iocb, struct iov_iter *from)
 875{
 876	struct file *file = iocb->ki_filp;
 877	struct inode *inode = file_inode(file);
 878	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 879	loff_t count;
 880
 881	if (IS_SWAPFILE(inode))
 882		return -ETXTBSY;
 883
 884	if (!iov_iter_count(from))
 885		return 0;
 886
 887	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
 888		return -EINVAL;
 889
 890	if (iocb->ki_flags & IOCB_APPEND) {
 891		if (zi->i_ztype != ZONEFS_ZTYPE_SEQ)
 892			return -EINVAL;
 893		mutex_lock(&zi->i_truncate_mutex);
 894		iocb->ki_pos = zi->i_wpoffset;
 895		mutex_unlock(&zi->i_truncate_mutex);
 896	}
 897
 898	count = zonefs_write_check_limits(file, iocb->ki_pos,
 899					  iov_iter_count(from));
 900	if (count < 0)
 901		return count;
 902
 903	iov_iter_truncate(from, count);
 904	return iov_iter_count(from);
 905}
 906
 907/*
 908 * Handle direct writes. For sequential zone files, this is the only possible
 909 * write path. For these files, check that the user is issuing writes
 910 * sequentially from the end of the file. This code assumes that the block layer
 911 * delivers write requests to the device in sequential order. This is always the
 912 * case if a block IO scheduler implementing the ELEVATOR_F_ZBD_SEQ_WRITE
 913 * elevator feature is being used (e.g. mq-deadline). The block layer always
 914 * automatically select such an elevator for zoned block devices during the
 915 * device initialization.
 916 */
 917static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
 918{
 919	struct inode *inode = file_inode(iocb->ki_filp);
 920	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 921	struct super_block *sb = inode->i_sb;
 922	bool sync = is_sync_kiocb(iocb);
 923	bool append = false;
 924	ssize_t ret, count;
 925
 926	/*
 927	 * For async direct IOs to sequential zone files, refuse IOCB_NOWAIT
 928	 * as this can cause write reordering (e.g. the first aio gets EAGAIN
 929	 * on the inode lock but the second goes through but is now unaligned).
 930	 */
 931	if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && !sync &&
 932	    (iocb->ki_flags & IOCB_NOWAIT))
 933		return -EOPNOTSUPP;
 934
 935	if (iocb->ki_flags & IOCB_NOWAIT) {
 936		if (!inode_trylock(inode))
 937			return -EAGAIN;
 938	} else {
 939		inode_lock(inode);
 940	}
 941
 942	count = zonefs_write_checks(iocb, from);
 943	if (count <= 0) {
 944		ret = count;
 945		goto inode_unlock;
 946	}
 947
 948	if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
 949		ret = -EINVAL;
 950		goto inode_unlock;
 951	}
 952
 953	/* Enforce sequential writes (append only) in sequential zones */
 954	if (zi->i_ztype == ZONEFS_ZTYPE_SEQ) {
 955		mutex_lock(&zi->i_truncate_mutex);
 956		if (iocb->ki_pos != zi->i_wpoffset) {
 957			mutex_unlock(&zi->i_truncate_mutex);
 958			ret = -EINVAL;
 959			goto inode_unlock;
 960		}
 961		mutex_unlock(&zi->i_truncate_mutex);
 962		append = sync;
 963	}
 964
 965	if (append)
 966		ret = zonefs_file_dio_append(iocb, from);
 967	else
 968		ret = iomap_dio_rw(iocb, from, &zonefs_write_iomap_ops,
 969				   &zonefs_write_dio_ops, 0, NULL, 0);
 970	if (zi->i_ztype == ZONEFS_ZTYPE_SEQ &&
 971	    (ret > 0 || ret == -EIOCBQUEUED)) {
 972		if (ret > 0)
 973			count = ret;
 974
 975		/*
 976		 * Update the zone write pointer offset assuming the write
 977		 * operation succeeded. If it did not, the error recovery path
 978		 * will correct it. Also do active seq file accounting.
 979		 */
 980		mutex_lock(&zi->i_truncate_mutex);
 981		zi->i_wpoffset += count;
 982		zonefs_account_active(inode);
 983		mutex_unlock(&zi->i_truncate_mutex);
 984	}
 985
 986inode_unlock:
 987	inode_unlock(inode);
 988
 989	return ret;
 990}
 991
 992static ssize_t zonefs_file_buffered_write(struct kiocb *iocb,
 993					  struct iov_iter *from)
 994{
 995	struct inode *inode = file_inode(iocb->ki_filp);
 996	struct zonefs_inode_info *zi = ZONEFS_I(inode);
 997	ssize_t ret;
 998
 999	/*
1000	 * Direct IO writes are mandatory for sequential zone files so that the
1001	 * write IO issuing order is preserved.
1002	 */
1003	if (zi->i_ztype != ZONEFS_ZTYPE_CNV)
1004		return -EIO;
1005
1006	if (iocb->ki_flags & IOCB_NOWAIT) {
1007		if (!inode_trylock(inode))
1008			return -EAGAIN;
1009	} else {
1010		inode_lock(inode);
1011	}
1012
1013	ret = zonefs_write_checks(iocb, from);
1014	if (ret <= 0)
1015		goto inode_unlock;
1016
1017	ret = iomap_file_buffered_write(iocb, from, &zonefs_write_iomap_ops);
1018	if (ret > 0)
1019		iocb->ki_pos += ret;
1020	else if (ret == -EIO)
1021		zonefs_io_error(inode, true);
1022
1023inode_unlock:
1024	inode_unlock(inode);
1025	if (ret > 0)
1026		ret = generic_write_sync(iocb, ret);
1027
1028	return ret;
1029}
1030
1031static ssize_t zonefs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
1032{
1033	struct inode *inode = file_inode(iocb->ki_filp);
1034
1035	if (unlikely(IS_IMMUTABLE(inode)))
1036		return -EPERM;
1037
1038	if (sb_rdonly(inode->i_sb))
1039		return -EROFS;
1040
1041	/* Write operations beyond the zone size are not allowed */
1042	if (iocb->ki_pos >= ZONEFS_I(inode)->i_max_size)
1043		return -EFBIG;
1044
1045	if (iocb->ki_flags & IOCB_DIRECT) {
1046		ssize_t ret = zonefs_file_dio_write(iocb, from);
1047		if (ret != -ENOTBLK)
1048			return ret;
1049	}
1050
1051	return zonefs_file_buffered_write(iocb, from);
1052}
1053
1054static int zonefs_file_read_dio_end_io(struct kiocb *iocb, ssize_t size,
1055				       int error, unsigned int flags)
1056{
1057	if (error) {
1058		zonefs_io_error(file_inode(iocb->ki_filp), false);
1059		return error;
1060	}
1061
1062	return 0;
1063}
1064
1065static const struct iomap_dio_ops zonefs_read_dio_ops = {
1066	.end_io			= zonefs_file_read_dio_end_io,
1067};
1068
1069static ssize_t zonefs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
1070{
1071	struct inode *inode = file_inode(iocb->ki_filp);
1072	struct zonefs_inode_info *zi = ZONEFS_I(inode);
1073	struct super_block *sb = inode->i_sb;
1074	loff_t isize;
1075	ssize_t ret;
1076
1077	/* Offline zones cannot be read */
1078	if (unlikely(IS_IMMUTABLE(inode) && !(inode->i_mode & 0777)))
1079		return -EPERM;
1080
1081	if (iocb->ki_pos >= zi->i_max_size)
1082		return 0;
1083
1084	if (iocb->ki_flags & IOCB_NOWAIT) {
1085		if (!inode_trylock_shared(inode))
1086			return -EAGAIN;
1087	} else {
1088		inode_lock_shared(inode);
1089	}
1090
1091	/* Limit read operations to written data */
1092	mutex_lock(&zi->i_truncate_mutex);
1093	isize = i_size_read(inode);
1094	if (iocb->ki_pos >= isize) {
1095		mutex_unlock(&zi->i_truncate_mutex);
1096		ret = 0;
1097		goto inode_unlock;
1098	}
1099	iov_iter_truncate(to, isize - iocb->ki_pos);
1100	mutex_unlock(&zi->i_truncate_mutex);
1101
1102	if (iocb->ki_flags & IOCB_DIRECT) {
1103		size_t count = iov_iter_count(to);
1104
1105		if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
1106			ret = -EINVAL;
1107			goto inode_unlock;
1108		}
1109		file_accessed(iocb->ki_filp);
1110		ret = iomap_dio_rw(iocb, to, &zonefs_read_iomap_ops,
1111				   &zonefs_read_dio_ops, 0, NULL, 0);
1112	} else {
1113		ret = generic_file_read_iter(iocb, to);
1114		if (ret == -EIO)
1115			zonefs_io_error(inode, false);
1116	}
1117
1118inode_unlock:
1119	inode_unlock_shared(inode);
1120
1121	return ret;
1122}
1123
1124/*
1125 * Write open accounting is done only for sequential files.
1126 */
1127static inline bool zonefs_seq_file_need_wro(struct inode *inode,
1128					    struct file *file)
1129{
1130	struct zonefs_inode_info *zi = ZONEFS_I(inode);
1131
1132	if (zi->i_ztype != ZONEFS_ZTYPE_SEQ)
1133		return false;
1134
1135	if (!(file->f_mode & FMODE_WRITE))
1136		return false;
1137
1138	return true;
1139}
1140
1141static int zonefs_seq_file_write_open(struct inode *inode)
1142{
1143	struct zonefs_inode_info *zi = ZONEFS_I(inode);
1144	int ret = 0;
1145
1146	mutex_lock(&zi->i_truncate_mutex);
1147
1148	if (!zi->i_wr_refcnt) {
1149		struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
1150		unsigned int wro = atomic_inc_return(&sbi->s_wro_seq_files);
1151
1152		if (sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) {
1153
1154			if (sbi->s_max_wro_seq_files
1155			    && wro > sbi->s_max_wro_seq_files) {
1156				atomic_dec(&sbi->s_wro_seq_files);
1157				ret = -EBUSY;
1158				goto unlock;
1159			}
1160
1161			if (i_size_read(inode) < zi->i_max_size) {
1162				ret = zonefs_zone_mgmt(inode, REQ_OP_ZONE_OPEN);
1163				if (ret) {
1164					atomic_dec(&sbi->s_wro_seq_files);
1165					goto unlock;
1166				}
1167				zi->i_flags |= ZONEFS_ZONE_OPEN;
1168				zonefs_account_active(inode);
1169			}
1170		}
1171	}
1172
1173	zi->i_wr_refcnt++;
1174
1175unlock:
1176	mutex_unlock(&zi->i_truncate_mutex);
1177
1178	return ret;
1179}
1180
1181static int zonefs_file_open(struct inode *inode, struct file *file)
1182{
1183	int ret;
1184
1185	ret = generic_file_open(inode, file);
1186	if (ret)
1187		return ret;
1188
1189	if (zonefs_seq_file_need_wro(inode, file))
1190		return zonefs_seq_file_write_open(inode);
1191
1192	return 0;
1193}
1194
1195static void zonefs_seq_file_write_close(struct inode *inode)
1196{
1197	struct zonefs_inode_info *zi = ZONEFS_I(inode);
1198	struct super_block *sb = inode->i_sb;
1199	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1200	int ret = 0;
1201
1202	mutex_lock(&zi->i_truncate_mutex);
1203
1204	zi->i_wr_refcnt--;
1205	if (zi->i_wr_refcnt)
1206		goto unlock;
1207
1208	/*
1209	 * The file zone may not be open anymore (e.g. the file was truncated to
1210	 * its maximum size or it was fully written). For this case, we only
1211	 * need to decrement the write open count.
1212	 */
1213	if (zi->i_flags & ZONEFS_ZONE_OPEN) {
1214		ret = zonefs_zone_mgmt(inode, REQ_OP_ZONE_CLOSE);
1215		if (ret) {
1216			__zonefs_io_error(inode, false);
1217			/*
1218			 * Leaving zones explicitly open may lead to a state
1219			 * where most zones cannot be written (zone resources
1220			 * exhausted). So take preventive action by remounting
1221			 * read-only.
1222			 */
1223			if (zi->i_flags & ZONEFS_ZONE_OPEN &&
1224			    !(sb->s_flags & SB_RDONLY)) {
1225				zonefs_warn(sb,
1226					"closing zone at %llu failed %d\n",
1227					zi->i_zsector, ret);
1228				zonefs_warn(sb,
1229					"remounting filesystem read-only\n");
1230				sb->s_flags |= SB_RDONLY;
1231			}
1232			goto unlock;
1233		}
1234
1235		zi->i_flags &= ~ZONEFS_ZONE_OPEN;
1236		zonefs_account_active(inode);
1237	}
1238
1239	atomic_dec(&sbi->s_wro_seq_files);
1240
1241unlock:
1242	mutex_unlock(&zi->i_truncate_mutex);
1243}
1244
1245static int zonefs_file_release(struct inode *inode, struct file *file)
1246{
1247	/*
1248	 * If we explicitly open a zone we must close it again as well, but the
1249	 * zone management operation can fail (either due to an IO error or as
1250	 * the zone has gone offline or read-only). Make sure we don't fail the
1251	 * close(2) for user-space.
1252	 */
1253	if (zonefs_seq_file_need_wro(inode, file))
1254		zonefs_seq_file_write_close(inode);
1255
1256	return 0;
1257}
1258
1259static const struct file_operations zonefs_file_operations = {
1260	.open		= zonefs_file_open,
1261	.release	= zonefs_file_release,
1262	.fsync		= zonefs_file_fsync,
1263	.mmap		= zonefs_file_mmap,
1264	.llseek		= zonefs_file_llseek,
1265	.read_iter	= zonefs_file_read_iter,
1266	.write_iter	= zonefs_file_write_iter,
1267	.splice_read	= generic_file_splice_read,
1268	.splice_write	= iter_file_splice_write,
1269	.iopoll		= iocb_bio_iopoll,
1270};
1271
1272static struct kmem_cache *zonefs_inode_cachep;
1273
1274static struct inode *zonefs_alloc_inode(struct super_block *sb)
1275{
1276	struct zonefs_inode_info *zi;
1277
1278	zi = alloc_inode_sb(sb, zonefs_inode_cachep, GFP_KERNEL);
1279	if (!zi)
1280		return NULL;
1281
1282	inode_init_once(&zi->i_vnode);
1283	mutex_init(&zi->i_truncate_mutex);
1284	zi->i_wr_refcnt = 0;
1285	zi->i_flags = 0;
1286
1287	return &zi->i_vnode;
1288}
1289
1290static void zonefs_free_inode(struct inode *inode)
1291{
1292	kmem_cache_free(zonefs_inode_cachep, ZONEFS_I(inode));
1293}
1294
1295/*
1296 * File system stat.
1297 */
1298static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf)
1299{
1300	struct super_block *sb = dentry->d_sb;
1301	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1302	enum zonefs_ztype t;
1303
1304	buf->f_type = ZONEFS_MAGIC;
1305	buf->f_bsize = sb->s_blocksize;
1306	buf->f_namelen = ZONEFS_NAME_MAX;
1307
1308	spin_lock(&sbi->s_lock);
1309
1310	buf->f_blocks = sbi->s_blocks;
1311	if (WARN_ON(sbi->s_used_blocks > sbi->s_blocks))
1312		buf->f_bfree = 0;
1313	else
1314		buf->f_bfree = buf->f_blocks - sbi->s_used_blocks;
1315	buf->f_bavail = buf->f_bfree;
1316
1317	for (t = 0; t < ZONEFS_ZTYPE_MAX; t++) {
1318		if (sbi->s_nr_files[t])
1319			buf->f_files += sbi->s_nr_files[t] + 1;
1320	}
1321	buf->f_ffree = 0;
1322
1323	spin_unlock(&sbi->s_lock);
1324
1325	buf->f_fsid = uuid_to_fsid(sbi->s_uuid.b);
1326
1327	return 0;
1328}
1329
1330enum {
1331	Opt_errors_ro, Opt_errors_zro, Opt_errors_zol, Opt_errors_repair,
1332	Opt_explicit_open, Opt_err,
1333};
1334
1335static const match_table_t tokens = {
1336	{ Opt_errors_ro,	"errors=remount-ro"},
1337	{ Opt_errors_zro,	"errors=zone-ro"},
1338	{ Opt_errors_zol,	"errors=zone-offline"},
1339	{ Opt_errors_repair,	"errors=repair"},
1340	{ Opt_explicit_open,	"explicit-open" },
1341	{ Opt_err,		NULL}
1342};
1343
1344static int zonefs_parse_options(struct super_block *sb, char *options)
1345{
1346	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1347	substring_t args[MAX_OPT_ARGS];
1348	char *p;
1349
1350	if (!options)
1351		return 0;
1352
1353	while ((p = strsep(&options, ",")) != NULL) {
1354		int token;
1355
1356		if (!*p)
1357			continue;
1358
1359		token = match_token(p, tokens, args);
1360		switch (token) {
1361		case Opt_errors_ro:
1362			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
1363			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_RO;
1364			break;
1365		case Opt_errors_zro:
1366			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
1367			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_ZRO;
1368			break;
1369		case Opt_errors_zol:
1370			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
1371			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_ZOL;
1372			break;
1373		case Opt_errors_repair:
1374			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
1375			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_REPAIR;
1376			break;
1377		case Opt_explicit_open:
1378			sbi->s_mount_opts |= ZONEFS_MNTOPT_EXPLICIT_OPEN;
1379			break;
1380		default:
1381			return -EINVAL;
1382		}
1383	}
1384
1385	return 0;
1386}
1387
1388static int zonefs_show_options(struct seq_file *seq, struct dentry *root)
1389{
1390	struct zonefs_sb_info *sbi = ZONEFS_SB(root->d_sb);
1391
1392	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO)
1393		seq_puts(seq, ",errors=remount-ro");
1394	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO)
1395		seq_puts(seq, ",errors=zone-ro");
1396	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL)
1397		seq_puts(seq, ",errors=zone-offline");
1398	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_REPAIR)
1399		seq_puts(seq, ",errors=repair");
1400
1401	return 0;
1402}
1403
1404static int zonefs_remount(struct super_block *sb, int *flags, char *data)
1405{
1406	sync_filesystem(sb);
1407
1408	return zonefs_parse_options(sb, data);
1409}
1410
1411static const struct super_operations zonefs_sops = {
1412	.alloc_inode	= zonefs_alloc_inode,
1413	.free_inode	= zonefs_free_inode,
1414	.statfs		= zonefs_statfs,
1415	.remount_fs	= zonefs_remount,
1416	.show_options	= zonefs_show_options,
1417};
 
1418
1419static const struct inode_operations zonefs_dir_inode_operations = {
1420	.lookup		= simple_lookup,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1421	.setattr	= zonefs_inode_setattr,
1422};
1423
1424static void zonefs_init_dir_inode(struct inode *parent, struct inode *inode,
1425				  enum zonefs_ztype type)
1426{
1427	struct super_block *sb = parent->i_sb;
 
 
 
 
 
1428
1429	inode->i_ino = bdev_nr_zones(sb->s_bdev) + type + 1;
1430	inode_init_owner(&init_user_ns, inode, parent, S_IFDIR | 0555);
1431	inode->i_op = &zonefs_dir_inode_operations;
1432	inode->i_fop = &simple_dir_operations;
1433	set_nlink(inode, 2);
1434	inc_nlink(parent);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1435}
1436
1437static int zonefs_init_file_inode(struct inode *inode, struct blk_zone *zone,
1438				  enum zonefs_ztype type)
1439{
1440	struct super_block *sb = inode->i_sb;
 
1441	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1442	struct zonefs_inode_info *zi = ZONEFS_I(inode);
1443	int ret = 0;
1444
1445	inode->i_ino = zone->start >> sbi->s_zone_sectors_shift;
1446	inode->i_mode = S_IFREG | sbi->s_perm;
1447
1448	zi->i_ztype = type;
1449	zi->i_zsector = zone->start;
1450	zi->i_zone_size = zone->len << SECTOR_SHIFT;
1451	if (zi->i_zone_size > bdev_zone_sectors(sb->s_bdev) << SECTOR_SHIFT &&
1452	    !(sbi->s_features & ZONEFS_F_AGGRCNV)) {
1453		zonefs_err(sb,
1454			   "zone size %llu doesn't match device's zone sectors %llu\n",
1455			   zi->i_zone_size,
1456			   bdev_zone_sectors(sb->s_bdev) << SECTOR_SHIFT);
1457		return -EINVAL;
 
 
 
 
 
 
1458	}
1459
1460	zi->i_max_size = min_t(loff_t, MAX_LFS_FILESIZE,
1461			       zone->capacity << SECTOR_SHIFT);
1462	zi->i_wpoffset = zonefs_check_zone_condition(inode, zone, true, true);
1463
1464	inode->i_uid = sbi->s_uid;
1465	inode->i_gid = sbi->s_gid;
1466	inode->i_size = zi->i_wpoffset;
1467	inode->i_blocks = zi->i_max_size >> SECTOR_SHIFT;
 
1468
1469	inode->i_op = &zonefs_file_inode_operations;
1470	inode->i_fop = &zonefs_file_operations;
1471	inode->i_mapping->a_ops = &zonefs_file_aops;
1472
1473	sb->s_maxbytes = max(zi->i_max_size, sb->s_maxbytes);
1474	sbi->s_blocks += zi->i_max_size >> sb->s_blocksize_bits;
1475	sbi->s_used_blocks += zi->i_wpoffset >> sb->s_blocksize_bits;
1476
1477	mutex_lock(&zi->i_truncate_mutex);
1478
1479	/*
1480	 * For sequential zones, make sure that any open zone is closed first
1481	 * to ensure that the initial number of open zones is 0, in sync with
1482	 * the open zone accounting done when the mount option
1483	 * ZONEFS_MNTOPT_EXPLICIT_OPEN is used.
1484	 */
1485	if (type == ZONEFS_ZTYPE_SEQ &&
1486	    (zone->cond == BLK_ZONE_COND_IMP_OPEN ||
1487	     zone->cond == BLK_ZONE_COND_EXP_OPEN)) {
1488		ret = zonefs_zone_mgmt(inode, REQ_OP_ZONE_CLOSE);
1489		if (ret)
1490			goto unlock;
1491	}
1492
1493	zonefs_account_active(inode);
1494
1495unlock:
1496	mutex_unlock(&zi->i_truncate_mutex);
1497
1498	return ret;
1499}
1500
1501static struct dentry *zonefs_create_inode(struct dentry *parent,
1502					const char *name, struct blk_zone *zone,
1503					enum zonefs_ztype type)
1504{
1505	struct inode *dir = d_inode(parent);
1506	struct dentry *dentry;
1507	struct inode *inode;
1508	int ret = -ENOMEM;
1509
1510	dentry = d_alloc_name(parent, name);
1511	if (!dentry)
1512		return ERR_PTR(ret);
1513
1514	inode = new_inode(parent->d_sb);
1515	if (!inode)
1516		goto dput;
 
 
 
 
 
 
 
 
 
 
1517
1518	inode->i_ctime = inode->i_mtime = inode->i_atime = dir->i_ctime;
1519	if (zone) {
1520		ret = zonefs_init_file_inode(inode, zone, type);
1521		if (ret) {
1522			iput(inode);
1523			goto dput;
1524		}
1525	} else {
1526		zonefs_init_dir_inode(dir, inode, type);
1527	}
1528
1529	d_add(dentry, inode);
1530	dir->i_size++;
1531
1532	return dentry;
 
1533
1534dput:
1535	dput(dentry);
1536
1537	return ERR_PTR(ret);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1538}
1539
1540struct zonefs_zone_data {
1541	struct super_block	*sb;
1542	unsigned int		nr_zones[ZONEFS_ZTYPE_MAX];
1543	struct blk_zone		*zones;
1544};
1545
1546/*
1547 * Create a zone group and populate it with zone files.
1548 */
1549static int zonefs_create_zgroup(struct zonefs_zone_data *zd,
1550				enum zonefs_ztype type)
 
 
 
 
 
 
 
1551{
1552	struct super_block *sb = zd->sb;
 
1553	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1554	struct blk_zone *zone, *next, *end;
1555	const char *zgroup_name;
1556	char *file_name;
1557	struct dentry *dir, *dent;
1558	unsigned int n = 0;
1559	int ret;
1560
1561	/* If the group is empty, there is nothing to do */
1562	if (!zd->nr_zones[type])
1563		return 0;
1564
1565	file_name = kmalloc(ZONEFS_NAME_MAX, GFP_KERNEL);
1566	if (!file_name)
1567		return -ENOMEM;
1568
1569	if (type == ZONEFS_ZTYPE_CNV)
1570		zgroup_name = "cnv";
1571	else
1572		zgroup_name = "seq";
 
 
 
 
 
1573
1574	dir = zonefs_create_inode(sb->s_root, zgroup_name, NULL, type);
1575	if (IS_ERR(dir)) {
1576		ret = PTR_ERR(dir);
1577		goto free;
 
 
1578	}
1579
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1580	/*
1581	 * The first zone contains the super block: skip it.
 
 
1582	 */
1583	end = zd->zones + bdev_nr_zones(sb->s_bdev);
1584	for (zone = &zd->zones[1]; zone < end; zone = next) {
1585
1586		next = zone + 1;
1587		if (zonefs_zone_type(zone) != type)
1588			continue;
1589
1590		/*
1591		 * For conventional zones, contiguous zones can be aggregated
1592		 * together to form larger files. Note that this overwrites the
1593		 * length of the first zone of the set of contiguous zones
1594		 * aggregated together. If one offline or read-only zone is
1595		 * found, assume that all zones aggregated have the same
1596		 * condition.
1597		 */
1598		if (type == ZONEFS_ZTYPE_CNV &&
1599		    (sbi->s_features & ZONEFS_F_AGGRCNV)) {
1600			for (; next < end; next++) {
1601				if (zonefs_zone_type(next) != type)
1602					break;
1603				zone->len += next->len;
1604				zone->capacity += next->capacity;
1605				if (next->cond == BLK_ZONE_COND_READONLY &&
1606				    zone->cond != BLK_ZONE_COND_OFFLINE)
1607					zone->cond = BLK_ZONE_COND_READONLY;
1608				else if (next->cond == BLK_ZONE_COND_OFFLINE)
1609					zone->cond = BLK_ZONE_COND_OFFLINE;
1610			}
1611			if (zone->capacity != zone->len) {
1612				zonefs_err(sb, "Invalid conventional zone capacity\n");
1613				ret = -EINVAL;
1614				goto free;
1615			}
1616		}
1617
1618		/*
1619		 * Use the file number within its group as file name.
1620		 */
1621		snprintf(file_name, ZONEFS_NAME_MAX - 1, "%u", n);
1622		dent = zonefs_create_inode(dir, file_name, zone, type);
1623		if (IS_ERR(dent)) {
1624			ret = PTR_ERR(dent);
1625			goto free;
1626		}
1627
1628		n++;
 
 
 
 
 
 
1629	}
1630
1631	zonefs_info(sb, "Zone group \"%s\" has %u file%s\n",
1632		    zgroup_name, n, n > 1 ? "s" : "");
1633
1634	sbi->s_nr_files[type] = n;
1635	ret = 0;
1636
1637free:
1638	kfree(file_name);
 
1639
1640	return ret;
 
 
 
1641}
1642
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1643static int zonefs_get_zone_info_cb(struct blk_zone *zone, unsigned int idx,
1644				   void *data)
1645{
1646	struct zonefs_zone_data *zd = data;
 
 
 
 
 
 
 
 
 
1647
1648	/*
1649	 * Count the number of usable zones: the first zone at index 0 contains
1650	 * the super block and is ignored.
 
 
1651	 */
1652	switch (zone->type) {
1653	case BLK_ZONE_TYPE_CONVENTIONAL:
1654		zone->wp = zone->start + zone->len;
1655		if (idx)
1656			zd->nr_zones[ZONEFS_ZTYPE_CNV]++;
 
 
 
 
 
 
 
1657		break;
1658	case BLK_ZONE_TYPE_SEQWRITE_REQ:
1659	case BLK_ZONE_TYPE_SEQWRITE_PREF:
1660		if (idx)
1661			zd->nr_zones[ZONEFS_ZTYPE_SEQ]++;
1662		break;
1663	default:
1664		zonefs_err(zd->sb, "Unsupported zone type 0x%x\n",
1665			   zone->type);
1666		return -EIO;
1667	}
1668
1669	memcpy(&zd->zones[idx], zone, sizeof(struct blk_zone));
1670
1671	return 0;
1672}
1673
1674static int zonefs_get_zone_info(struct zonefs_zone_data *zd)
1675{
1676	struct block_device *bdev = zd->sb->s_bdev;
1677	int ret;
1678
1679	zd->zones = kvcalloc(bdev_nr_zones(bdev), sizeof(struct blk_zone),
1680			     GFP_KERNEL);
1681	if (!zd->zones)
1682		return -ENOMEM;
1683
1684	/* Get zones information from the device */
1685	ret = blkdev_report_zones(bdev, 0, BLK_ALL_ZONES,
1686				  zonefs_get_zone_info_cb, zd);
1687	if (ret < 0) {
1688		zonefs_err(zd->sb, "Zone report failed %d\n", ret);
1689		return ret;
1690	}
1691
1692	if (ret != bdev_nr_zones(bdev)) {
1693		zonefs_err(zd->sb, "Invalid zone report (%d/%u zones)\n",
1694			   ret, bdev_nr_zones(bdev));
1695		return -EIO;
1696	}
1697
1698	return 0;
1699}
1700
1701static inline void zonefs_cleanup_zone_info(struct zonefs_zone_data *zd)
1702{
1703	kvfree(zd->zones);
1704}
1705
1706/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1707 * Read super block information from the device.
1708 */
1709static int zonefs_read_super(struct super_block *sb)
1710{
1711	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1712	struct zonefs_super *super;
1713	u32 crc, stored_crc;
1714	struct page *page;
1715	struct bio_vec bio_vec;
1716	struct bio bio;
1717	int ret;
1718
1719	page = alloc_page(GFP_KERNEL);
1720	if (!page)
1721		return -ENOMEM;
1722
1723	bio_init(&bio, sb->s_bdev, &bio_vec, 1, REQ_OP_READ);
1724	bio.bi_iter.bi_sector = 0;
1725	bio_add_page(&bio, page, PAGE_SIZE, 0);
1726
1727	ret = submit_bio_wait(&bio);
1728	if (ret)
1729		goto free_page;
1730
1731	super = page_address(page);
1732
1733	ret = -EINVAL;
1734	if (le32_to_cpu(super->s_magic) != ZONEFS_MAGIC)
1735		goto free_page;
1736
1737	stored_crc = le32_to_cpu(super->s_crc);
1738	super->s_crc = 0;
1739	crc = crc32(~0U, (unsigned char *)super, sizeof(struct zonefs_super));
1740	if (crc != stored_crc) {
1741		zonefs_err(sb, "Invalid checksum (Expected 0x%08x, got 0x%08x)",
1742			   crc, stored_crc);
1743		goto free_page;
1744	}
1745
1746	sbi->s_features = le64_to_cpu(super->s_features);
1747	if (sbi->s_features & ~ZONEFS_F_DEFINED_FEATURES) {
1748		zonefs_err(sb, "Unknown features set 0x%llx\n",
1749			   sbi->s_features);
1750		goto free_page;
1751	}
1752
1753	if (sbi->s_features & ZONEFS_F_UID) {
1754		sbi->s_uid = make_kuid(current_user_ns(),
1755				       le32_to_cpu(super->s_uid));
1756		if (!uid_valid(sbi->s_uid)) {
1757			zonefs_err(sb, "Invalid UID feature\n");
1758			goto free_page;
1759		}
1760	}
1761
1762	if (sbi->s_features & ZONEFS_F_GID) {
1763		sbi->s_gid = make_kgid(current_user_ns(),
1764				       le32_to_cpu(super->s_gid));
1765		if (!gid_valid(sbi->s_gid)) {
1766			zonefs_err(sb, "Invalid GID feature\n");
1767			goto free_page;
1768		}
1769	}
1770
1771	if (sbi->s_features & ZONEFS_F_PERM)
1772		sbi->s_perm = le32_to_cpu(super->s_perm);
1773
1774	if (memchr_inv(super->s_reserved, 0, sizeof(super->s_reserved))) {
1775		zonefs_err(sb, "Reserved area is being used\n");
1776		goto free_page;
1777	}
1778
1779	import_uuid(&sbi->s_uuid, super->s_uuid);
1780	ret = 0;
1781
1782free_page:
1783	__free_page(page);
1784
1785	return ret;
1786}
1787
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1788/*
1789 * Check that the device is zoned. If it is, get the list of zones and create
1790 * sub-directories and files according to the device zone configuration and
1791 * format options.
1792 */
1793static int zonefs_fill_super(struct super_block *sb, void *data, int silent)
1794{
1795	struct zonefs_zone_data zd;
1796	struct zonefs_sb_info *sbi;
1797	struct inode *inode;
1798	enum zonefs_ztype t;
1799	int ret;
1800
1801	if (!bdev_is_zoned(sb->s_bdev)) {
1802		zonefs_err(sb, "Not a zoned block device\n");
1803		return -EINVAL;
1804	}
1805
1806	/*
1807	 * Initialize super block information: the maximum file size is updated
1808	 * when the zone files are created so that the format option
1809	 * ZONEFS_F_AGGRCNV which increases the maximum file size of a file
1810	 * beyond the zone size is taken into account.
1811	 */
1812	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1813	if (!sbi)
1814		return -ENOMEM;
1815
1816	spin_lock_init(&sbi->s_lock);
1817	sb->s_fs_info = sbi;
1818	sb->s_magic = ZONEFS_MAGIC;
1819	sb->s_maxbytes = 0;
1820	sb->s_op = &zonefs_sops;
1821	sb->s_time_gran	= 1;
1822
1823	/*
1824	 * The block size is set to the device zone write granularity to ensure
1825	 * that write operations are always aligned according to the device
1826	 * interface constraints.
1827	 */
1828	sb_set_blocksize(sb, bdev_zone_write_granularity(sb->s_bdev));
1829	sbi->s_zone_sectors_shift = ilog2(bdev_zone_sectors(sb->s_bdev));
1830	sbi->s_uid = GLOBAL_ROOT_UID;
1831	sbi->s_gid = GLOBAL_ROOT_GID;
1832	sbi->s_perm = 0640;
1833	sbi->s_mount_opts = ZONEFS_MNTOPT_ERRORS_RO;
1834
1835	atomic_set(&sbi->s_wro_seq_files, 0);
1836	sbi->s_max_wro_seq_files = bdev_max_open_zones(sb->s_bdev);
1837	atomic_set(&sbi->s_active_seq_files, 0);
1838	sbi->s_max_active_seq_files = bdev_max_active_zones(sb->s_bdev);
1839
1840	ret = zonefs_read_super(sb);
1841	if (ret)
1842		return ret;
1843
1844	ret = zonefs_parse_options(sb, data);
1845	if (ret)
1846		return ret;
1847
1848	memset(&zd, 0, sizeof(struct zonefs_zone_data));
1849	zd.sb = sb;
1850	ret = zonefs_get_zone_info(&zd);
1851	if (ret)
1852		goto cleanup;
1853
1854	ret = zonefs_sysfs_register(sb);
1855	if (ret)
1856		goto cleanup;
1857
1858	zonefs_info(sb, "Mounting %u zones", bdev_nr_zones(sb->s_bdev));
1859
1860	if (!sbi->s_max_wro_seq_files &&
1861	    !sbi->s_max_active_seq_files &&
1862	    sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) {
1863		zonefs_info(sb,
1864			"No open and active zone limits. Ignoring explicit_open mount option\n");
1865		sbi->s_mount_opts &= ~ZONEFS_MNTOPT_EXPLICIT_OPEN;
1866	}
1867
1868	/* Create root directory inode */
 
 
 
 
 
1869	ret = -ENOMEM;
1870	inode = new_inode(sb);
1871	if (!inode)
1872		goto cleanup;
1873
1874	inode->i_ino = bdev_nr_zones(sb->s_bdev);
1875	inode->i_mode = S_IFDIR | 0555;
1876	inode->i_ctime = inode->i_mtime = inode->i_atime = current_time(inode);
1877	inode->i_op = &zonefs_dir_inode_operations;
1878	inode->i_fop = &simple_dir_operations;
 
1879	set_nlink(inode, 2);
 
 
 
 
 
 
1880
1881	sb->s_root = d_make_root(inode);
1882	if (!sb->s_root)
1883		goto cleanup;
1884
1885	/* Create and populate files in zone groups directories */
1886	for (t = 0; t < ZONEFS_ZTYPE_MAX; t++) {
1887		ret = zonefs_create_zgroup(&zd, t);
1888		if (ret)
1889			break;
1890	}
 
 
 
 
 
 
 
1891
1892cleanup:
1893	zonefs_cleanup_zone_info(&zd);
 
1894
1895	return ret;
1896}
1897
1898static struct dentry *zonefs_mount(struct file_system_type *fs_type,
1899				   int flags, const char *dev_name, void *data)
1900{
1901	return mount_bdev(fs_type, flags, dev_name, data, zonefs_fill_super);
1902}
1903
1904static void zonefs_kill_super(struct super_block *sb)
1905{
1906	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1907
1908	if (sb->s_root)
1909		d_genocide(sb->s_root);
1910
1911	zonefs_sysfs_unregister(sb);
1912	kill_block_super(sb);
 
 
 
1913	kfree(sbi);
1914}
1915
1916/*
1917 * File system definition and registration.
1918 */
1919static struct file_system_type zonefs_type = {
1920	.owner		= THIS_MODULE,
1921	.name		= "zonefs",
1922	.mount		= zonefs_mount,
1923	.kill_sb	= zonefs_kill_super,
1924	.fs_flags	= FS_REQUIRES_DEV,
1925};
1926
1927static int __init zonefs_init_inodecache(void)
1928{
1929	zonefs_inode_cachep = kmem_cache_create("zonefs_inode_cache",
1930			sizeof(struct zonefs_inode_info), 0,
1931			(SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT),
1932			NULL);
1933	if (zonefs_inode_cachep == NULL)
1934		return -ENOMEM;
1935	return 0;
1936}
1937
1938static void zonefs_destroy_inodecache(void)
1939{
1940	/*
1941	 * Make sure all delayed rcu free inodes are flushed before we
1942	 * destroy the inode cache.
1943	 */
1944	rcu_barrier();
1945	kmem_cache_destroy(zonefs_inode_cachep);
1946}
1947
1948static int __init zonefs_init(void)
1949{
1950	int ret;
1951
1952	BUILD_BUG_ON(sizeof(struct zonefs_super) != ZONEFS_SUPER_SIZE);
1953
1954	ret = zonefs_init_inodecache();
1955	if (ret)
1956		return ret;
1957
1958	ret = zonefs_sysfs_init();
1959	if (ret)
1960		goto destroy_inodecache;
1961
1962	ret = register_filesystem(&zonefs_type);
1963	if (ret)
1964		goto sysfs_exit;
1965
1966	return 0;
1967
1968sysfs_exit:
1969	zonefs_sysfs_exit();
1970destroy_inodecache:
1971	zonefs_destroy_inodecache();
1972
1973	return ret;
1974}
1975
1976static void __exit zonefs_exit(void)
1977{
1978	unregister_filesystem(&zonefs_type);
1979	zonefs_sysfs_exit();
1980	zonefs_destroy_inodecache();
1981}
1982
1983MODULE_AUTHOR("Damien Le Moal");
1984MODULE_DESCRIPTION("Zone file system for zoned block devices");
1985MODULE_LICENSE("GPL");
1986MODULE_ALIAS_FS("zonefs");
1987module_init(zonefs_init);
1988module_exit(zonefs_exit);