xref: /openbmc/linux/fs/zonefs/super.c (revision 747f7a29)
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  */
33 static 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 	 * If the zone is active, that is, if it is explicitly open or
45 	 * partially written, check if it was already accounted as active.
46 	 */
47 	if ((zi->i_flags & ZONEFS_ZONE_OPEN) ||
48 	    (zi->i_wpoffset > 0 && zi->i_wpoffset < zi->i_max_size)) {
49 		if (!(zi->i_flags & ZONEFS_ZONE_ACTIVE)) {
50 			zi->i_flags |= ZONEFS_ZONE_ACTIVE;
51 			atomic_inc(&sbi->s_active_seq_files);
52 		}
53 		return;
54 	}
55 
56 	/* The zone is not active. If it was, update the active count */
57 	if (zi->i_flags & ZONEFS_ZONE_ACTIVE) {
58 		zi->i_flags &= ~ZONEFS_ZONE_ACTIVE;
59 		atomic_dec(&sbi->s_active_seq_files);
60 	}
61 }
62 
63 static inline int zonefs_zone_mgmt(struct inode *inode, enum req_op op)
64 {
65 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
66 	int ret;
67 
68 	lockdep_assert_held(&zi->i_truncate_mutex);
69 
70 	/*
71 	 * With ZNS drives, closing an explicitly open zone that has not been
72 	 * written will change the zone state to "closed", that is, the zone
73 	 * will remain active. Since this can then cause failure of explicit
74 	 * open operation on other zones if the drive active zone resources
75 	 * are exceeded, make sure that the zone does not remain active by
76 	 * resetting it.
77 	 */
78 	if (op == REQ_OP_ZONE_CLOSE && !zi->i_wpoffset)
79 		op = REQ_OP_ZONE_RESET;
80 
81 	trace_zonefs_zone_mgmt(inode, op);
82 	ret = blkdev_zone_mgmt(inode->i_sb->s_bdev, op, zi->i_zsector,
83 			       zi->i_zone_size >> SECTOR_SHIFT, GFP_NOFS);
84 	if (ret) {
85 		zonefs_err(inode->i_sb,
86 			   "Zone management operation %s at %llu failed %d\n",
87 			   blk_op_str(op), zi->i_zsector, ret);
88 		return ret;
89 	}
90 
91 	return 0;
92 }
93 
94 static inline void zonefs_i_size_write(struct inode *inode, loff_t isize)
95 {
96 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
97 
98 	i_size_write(inode, isize);
99 	/*
100 	 * A full zone is no longer open/active and does not need
101 	 * explicit closing.
102 	 */
103 	if (isize >= zi->i_max_size) {
104 		struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
105 
106 		if (zi->i_flags & ZONEFS_ZONE_ACTIVE)
107 			atomic_dec(&sbi->s_active_seq_files);
108 		zi->i_flags &= ~(ZONEFS_ZONE_OPEN | ZONEFS_ZONE_ACTIVE);
109 	}
110 }
111 
112 static int zonefs_read_iomap_begin(struct inode *inode, loff_t offset,
113 				   loff_t length, unsigned int flags,
114 				   struct iomap *iomap, struct iomap *srcmap)
115 {
116 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
117 	struct super_block *sb = inode->i_sb;
118 	loff_t isize;
119 
120 	/*
121 	 * All blocks are always mapped below EOF. If reading past EOF,
122 	 * act as if there is a hole up to the file maximum size.
123 	 */
124 	mutex_lock(&zi->i_truncate_mutex);
125 	iomap->bdev = inode->i_sb->s_bdev;
126 	iomap->offset = ALIGN_DOWN(offset, sb->s_blocksize);
127 	isize = i_size_read(inode);
128 	if (iomap->offset >= isize) {
129 		iomap->type = IOMAP_HOLE;
130 		iomap->addr = IOMAP_NULL_ADDR;
131 		iomap->length = length;
132 	} else {
133 		iomap->type = IOMAP_MAPPED;
134 		iomap->addr = (zi->i_zsector << SECTOR_SHIFT) + iomap->offset;
135 		iomap->length = isize - iomap->offset;
136 	}
137 	mutex_unlock(&zi->i_truncate_mutex);
138 
139 	trace_zonefs_iomap_begin(inode, iomap);
140 
141 	return 0;
142 }
143 
144 static const struct iomap_ops zonefs_read_iomap_ops = {
145 	.iomap_begin	= zonefs_read_iomap_begin,
146 };
147 
148 static int zonefs_write_iomap_begin(struct inode *inode, loff_t offset,
149 				    loff_t length, unsigned int flags,
150 				    struct iomap *iomap, struct iomap *srcmap)
151 {
152 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
153 	struct super_block *sb = inode->i_sb;
154 	loff_t isize;
155 
156 	/* All write I/Os should always be within the file maximum size */
157 	if (WARN_ON_ONCE(offset + length > zi->i_max_size))
158 		return -EIO;
159 
160 	/*
161 	 * Sequential zones can only accept direct writes. This is already
162 	 * checked when writes are issued, so warn if we see a page writeback
163 	 * operation.
164 	 */
165 	if (WARN_ON_ONCE(zi->i_ztype == ZONEFS_ZTYPE_SEQ &&
166 			 !(flags & IOMAP_DIRECT)))
167 		return -EIO;
168 
169 	/*
170 	 * For conventional zones, all blocks are always mapped. For sequential
171 	 * zones, all blocks after always mapped below the inode size (zone
172 	 * write pointer) and unwriten beyond.
173 	 */
174 	mutex_lock(&zi->i_truncate_mutex);
175 	iomap->bdev = inode->i_sb->s_bdev;
176 	iomap->offset = ALIGN_DOWN(offset, sb->s_blocksize);
177 	iomap->addr = (zi->i_zsector << SECTOR_SHIFT) + iomap->offset;
178 	isize = i_size_read(inode);
179 	if (iomap->offset >= isize) {
180 		iomap->type = IOMAP_UNWRITTEN;
181 		iomap->length = zi->i_max_size - iomap->offset;
182 	} else {
183 		iomap->type = IOMAP_MAPPED;
184 		iomap->length = isize - iomap->offset;
185 	}
186 	mutex_unlock(&zi->i_truncate_mutex);
187 
188 	trace_zonefs_iomap_begin(inode, iomap);
189 
190 	return 0;
191 }
192 
193 static const struct iomap_ops zonefs_write_iomap_ops = {
194 	.iomap_begin	= zonefs_write_iomap_begin,
195 };
196 
197 static int zonefs_read_folio(struct file *unused, struct folio *folio)
198 {
199 	return iomap_read_folio(folio, &zonefs_read_iomap_ops);
200 }
201 
202 static void zonefs_readahead(struct readahead_control *rac)
203 {
204 	iomap_readahead(rac, &zonefs_read_iomap_ops);
205 }
206 
207 /*
208  * Map blocks for page writeback. This is used only on conventional zone files,
209  * which implies that the page range can only be within the fixed inode size.
210  */
211 static int zonefs_write_map_blocks(struct iomap_writepage_ctx *wpc,
212 				   struct inode *inode, loff_t offset)
213 {
214 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
215 
216 	if (WARN_ON_ONCE(zi->i_ztype != ZONEFS_ZTYPE_CNV))
217 		return -EIO;
218 	if (WARN_ON_ONCE(offset >= i_size_read(inode)))
219 		return -EIO;
220 
221 	/* If the mapping is already OK, nothing needs to be done */
222 	if (offset >= wpc->iomap.offset &&
223 	    offset < wpc->iomap.offset + wpc->iomap.length)
224 		return 0;
225 
226 	return zonefs_write_iomap_begin(inode, offset, zi->i_max_size - offset,
227 					IOMAP_WRITE, &wpc->iomap, NULL);
228 }
229 
230 static const struct iomap_writeback_ops zonefs_writeback_ops = {
231 	.map_blocks		= zonefs_write_map_blocks,
232 };
233 
234 static int zonefs_writepage(struct page *page, struct writeback_control *wbc)
235 {
236 	struct iomap_writepage_ctx wpc = { };
237 
238 	return iomap_writepage(page, wbc, &wpc, &zonefs_writeback_ops);
239 }
240 
241 static int zonefs_writepages(struct address_space *mapping,
242 			     struct writeback_control *wbc)
243 {
244 	struct iomap_writepage_ctx wpc = { };
245 
246 	return iomap_writepages(mapping, wbc, &wpc, &zonefs_writeback_ops);
247 }
248 
249 static int zonefs_swap_activate(struct swap_info_struct *sis,
250 				struct file *swap_file, sector_t *span)
251 {
252 	struct inode *inode = file_inode(swap_file);
253 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
254 
255 	if (zi->i_ztype != ZONEFS_ZTYPE_CNV) {
256 		zonefs_err(inode->i_sb,
257 			   "swap file: not a conventional zone file\n");
258 		return -EINVAL;
259 	}
260 
261 	return iomap_swapfile_activate(sis, swap_file, span,
262 				       &zonefs_read_iomap_ops);
263 }
264 
265 static const struct address_space_operations zonefs_file_aops = {
266 	.read_folio		= zonefs_read_folio,
267 	.readahead		= zonefs_readahead,
268 	.writepage		= zonefs_writepage,
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 
280 static 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  */
317 static 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 		return 0;
336 	case BLK_ZONE_COND_READONLY:
337 		/*
338 		 * The write pointer of read-only zones is invalid. If such a
339 		 * zone is found during mount, the file size cannot be retrieved
340 		 * so we treat the zone as offline (mount == true case).
341 		 * Otherwise, keep the file size as it was when last updated
342 		 * so that the user can recover data. In both cases, writes are
343 		 * always disabled for the zone.
344 		 */
345 		if (warn)
346 			zonefs_warn(inode->i_sb, "inode %lu: read-only zone\n",
347 				    inode->i_ino);
348 		inode->i_flags |= S_IMMUTABLE;
349 		if (mount) {
350 			zone->cond = BLK_ZONE_COND_OFFLINE;
351 			inode->i_mode &= ~0777;
352 			zone->wp = zone->start;
353 			return 0;
354 		}
355 		inode->i_mode &= ~0222;
356 		return i_size_read(inode);
357 	case BLK_ZONE_COND_FULL:
358 		/* The write pointer of full zones is invalid. */
359 		return zi->i_max_size;
360 	default:
361 		if (zi->i_ztype == ZONEFS_ZTYPE_CNV)
362 			return zi->i_max_size;
363 		return (zone->wp - zone->start) << SECTOR_SHIFT;
364 	}
365 }
366 
367 struct zonefs_ioerr_data {
368 	struct inode	*inode;
369 	bool		write;
370 };
371 
372 static int zonefs_io_error_cb(struct blk_zone *zone, unsigned int idx,
373 			      void *data)
374 {
375 	struct zonefs_ioerr_data *err = data;
376 	struct inode *inode = err->inode;
377 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
378 	struct super_block *sb = inode->i_sb;
379 	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
380 	loff_t isize, data_size;
381 
382 	/*
383 	 * Check the zone condition: if the zone is not "bad" (offline or
384 	 * read-only), read errors are simply signaled to the IO issuer as long
385 	 * as there is no inconsistency between the inode size and the amount of
386 	 * data writen in the zone (data_size).
387 	 */
388 	data_size = zonefs_check_zone_condition(inode, zone, true, false);
389 	isize = i_size_read(inode);
390 	if (zone->cond != BLK_ZONE_COND_OFFLINE &&
391 	    zone->cond != BLK_ZONE_COND_READONLY &&
392 	    !err->write && isize == data_size)
393 		return 0;
394 
395 	/*
396 	 * At this point, we detected either a bad zone or an inconsistency
397 	 * between the inode size and the amount of data written in the zone.
398 	 * For the latter case, the cause may be a write IO error or an external
399 	 * action on the device. Two error patterns exist:
400 	 * 1) The inode size is lower than the amount of data in the zone:
401 	 *    a write operation partially failed and data was writen at the end
402 	 *    of the file. This can happen in the case of a large direct IO
403 	 *    needing several BIOs and/or write requests to be processed.
404 	 * 2) The inode size is larger than the amount of data in the zone:
405 	 *    this can happen with a deferred write error with the use of the
406 	 *    device side write cache after getting successful write IO
407 	 *    completions. Other possibilities are (a) an external corruption,
408 	 *    e.g. an application reset the zone directly, or (b) the device
409 	 *    has a serious problem (e.g. firmware bug).
410 	 *
411 	 * In all cases, warn about inode size inconsistency and handle the
412 	 * IO error according to the zone condition and to the mount options.
413 	 */
414 	if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && isize != data_size)
415 		zonefs_warn(sb, "inode %lu: invalid size %lld (should be %lld)\n",
416 			    inode->i_ino, isize, data_size);
417 
418 	/*
419 	 * First handle bad zones signaled by hardware. The mount options
420 	 * errors=zone-ro and errors=zone-offline result in changing the
421 	 * zone condition to read-only and offline respectively, as if the
422 	 * condition was signaled by the hardware.
423 	 */
424 	if (zone->cond == BLK_ZONE_COND_OFFLINE ||
425 	    sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL) {
426 		zonefs_warn(sb, "inode %lu: read/write access disabled\n",
427 			    inode->i_ino);
428 		if (zone->cond != BLK_ZONE_COND_OFFLINE) {
429 			zone->cond = BLK_ZONE_COND_OFFLINE;
430 			data_size = zonefs_check_zone_condition(inode, zone,
431 								false, false);
432 		}
433 	} else if (zone->cond == BLK_ZONE_COND_READONLY ||
434 		   sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO) {
435 		zonefs_warn(sb, "inode %lu: write access disabled\n",
436 			    inode->i_ino);
437 		if (zone->cond != BLK_ZONE_COND_READONLY) {
438 			zone->cond = BLK_ZONE_COND_READONLY;
439 			data_size = zonefs_check_zone_condition(inode, zone,
440 								false, false);
441 		}
442 	}
443 
444 	/*
445 	 * If the filesystem is mounted with the explicit-open mount option, we
446 	 * need to clear the ZONEFS_ZONE_OPEN flag if the zone transitioned to
447 	 * the read-only or offline condition, to avoid attempting an explicit
448 	 * close of the zone when the inode file is closed.
449 	 */
450 	if ((sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) &&
451 	    (zone->cond == BLK_ZONE_COND_OFFLINE ||
452 	     zone->cond == BLK_ZONE_COND_READONLY))
453 		zi->i_flags &= ~ZONEFS_ZONE_OPEN;
454 
455 	/*
456 	 * If error=remount-ro was specified, any error result in remounting
457 	 * the volume as read-only.
458 	 */
459 	if ((sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO) && !sb_rdonly(sb)) {
460 		zonefs_warn(sb, "remounting filesystem read-only\n");
461 		sb->s_flags |= SB_RDONLY;
462 	}
463 
464 	/*
465 	 * Update block usage stats and the inode size  to prevent access to
466 	 * invalid data.
467 	 */
468 	zonefs_update_stats(inode, data_size);
469 	zonefs_i_size_write(inode, data_size);
470 	zi->i_wpoffset = data_size;
471 	zonefs_account_active(inode);
472 
473 	return 0;
474 }
475 
476 /*
477  * When an file IO error occurs, check the file zone to see if there is a change
478  * in the zone condition (e.g. offline or read-only). For a failed write to a
479  * sequential zone, the zone write pointer position must also be checked to
480  * eventually correct the file size and zonefs inode write pointer offset
481  * (which can be out of sync with the drive due to partial write failures).
482  */
483 static void __zonefs_io_error(struct inode *inode, bool write)
484 {
485 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
486 	struct super_block *sb = inode->i_sb;
487 	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
488 	unsigned int noio_flag;
489 	unsigned int nr_zones =
490 		zi->i_zone_size >> (sbi->s_zone_sectors_shift + SECTOR_SHIFT);
491 	struct zonefs_ioerr_data err = {
492 		.inode = inode,
493 		.write = write,
494 	};
495 	int ret;
496 
497 	/*
498 	 * Memory allocations in blkdev_report_zones() can trigger a memory
499 	 * reclaim which may in turn cause a recursion into zonefs as well as
500 	 * struct request allocations for the same device. The former case may
501 	 * end up in a deadlock on the inode truncate mutex, while the latter
502 	 * may prevent IO forward progress. Executing the report zones under
503 	 * the GFP_NOIO context avoids both problems.
504 	 */
505 	noio_flag = memalloc_noio_save();
506 	ret = blkdev_report_zones(sb->s_bdev, zi->i_zsector, nr_zones,
507 				  zonefs_io_error_cb, &err);
508 	if (ret != nr_zones)
509 		zonefs_err(sb, "Get inode %lu zone information failed %d\n",
510 			   inode->i_ino, ret);
511 	memalloc_noio_restore(noio_flag);
512 }
513 
514 static void zonefs_io_error(struct inode *inode, bool write)
515 {
516 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
517 
518 	mutex_lock(&zi->i_truncate_mutex);
519 	__zonefs_io_error(inode, write);
520 	mutex_unlock(&zi->i_truncate_mutex);
521 }
522 
523 static int zonefs_file_truncate(struct inode *inode, loff_t isize)
524 {
525 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
526 	loff_t old_isize;
527 	enum req_op op;
528 	int ret = 0;
529 
530 	/*
531 	 * Only sequential zone files can be truncated and truncation is allowed
532 	 * only down to a 0 size, which is equivalent to a zone reset, and to
533 	 * the maximum file size, which is equivalent to a zone finish.
534 	 */
535 	if (zi->i_ztype != ZONEFS_ZTYPE_SEQ)
536 		return -EPERM;
537 
538 	if (!isize)
539 		op = REQ_OP_ZONE_RESET;
540 	else if (isize == zi->i_max_size)
541 		op = REQ_OP_ZONE_FINISH;
542 	else
543 		return -EPERM;
544 
545 	inode_dio_wait(inode);
546 
547 	/* Serialize against page faults */
548 	filemap_invalidate_lock(inode->i_mapping);
549 
550 	/* Serialize against zonefs_iomap_begin() */
551 	mutex_lock(&zi->i_truncate_mutex);
552 
553 	old_isize = i_size_read(inode);
554 	if (isize == old_isize)
555 		goto unlock;
556 
557 	ret = zonefs_zone_mgmt(inode, op);
558 	if (ret)
559 		goto unlock;
560 
561 	/*
562 	 * If the mount option ZONEFS_MNTOPT_EXPLICIT_OPEN is set,
563 	 * take care of open zones.
564 	 */
565 	if (zi->i_flags & ZONEFS_ZONE_OPEN) {
566 		/*
567 		 * Truncating a zone to EMPTY or FULL is the equivalent of
568 		 * closing the zone. For a truncation to 0, we need to
569 		 * re-open the zone to ensure new writes can be processed.
570 		 * For a truncation to the maximum file size, the zone is
571 		 * closed and writes cannot be accepted anymore, so clear
572 		 * the open flag.
573 		 */
574 		if (!isize)
575 			ret = zonefs_zone_mgmt(inode, REQ_OP_ZONE_OPEN);
576 		else
577 			zi->i_flags &= ~ZONEFS_ZONE_OPEN;
578 	}
579 
580 	zonefs_update_stats(inode, isize);
581 	truncate_setsize(inode, isize);
582 	zi->i_wpoffset = isize;
583 	zonefs_account_active(inode);
584 
585 unlock:
586 	mutex_unlock(&zi->i_truncate_mutex);
587 	filemap_invalidate_unlock(inode->i_mapping);
588 
589 	return ret;
590 }
591 
592 static int zonefs_inode_setattr(struct user_namespace *mnt_userns,
593 				struct dentry *dentry, struct iattr *iattr)
594 {
595 	struct inode *inode = d_inode(dentry);
596 	int ret;
597 
598 	if (unlikely(IS_IMMUTABLE(inode)))
599 		return -EPERM;
600 
601 	ret = setattr_prepare(&init_user_ns, dentry, iattr);
602 	if (ret)
603 		return ret;
604 
605 	/*
606 	 * Since files and directories cannot be created nor deleted, do not
607 	 * allow setting any write attributes on the sub-directories grouping
608 	 * files by zone type.
609 	 */
610 	if ((iattr->ia_valid & ATTR_MODE) && S_ISDIR(inode->i_mode) &&
611 	    (iattr->ia_mode & 0222))
612 		return -EPERM;
613 
614 	if (((iattr->ia_valid & ATTR_UID) &&
615 	     !uid_eq(iattr->ia_uid, inode->i_uid)) ||
616 	    ((iattr->ia_valid & ATTR_GID) &&
617 	     !gid_eq(iattr->ia_gid, inode->i_gid))) {
618 		ret = dquot_transfer(mnt_userns, inode, iattr);
619 		if (ret)
620 			return ret;
621 	}
622 
623 	if (iattr->ia_valid & ATTR_SIZE) {
624 		ret = zonefs_file_truncate(inode, iattr->ia_size);
625 		if (ret)
626 			return ret;
627 	}
628 
629 	setattr_copy(&init_user_ns, inode, iattr);
630 
631 	return 0;
632 }
633 
634 static const struct inode_operations zonefs_file_inode_operations = {
635 	.setattr	= zonefs_inode_setattr,
636 };
637 
638 static int zonefs_file_fsync(struct file *file, loff_t start, loff_t end,
639 			     int datasync)
640 {
641 	struct inode *inode = file_inode(file);
642 	int ret = 0;
643 
644 	if (unlikely(IS_IMMUTABLE(inode)))
645 		return -EPERM;
646 
647 	/*
648 	 * Since only direct writes are allowed in sequential files, page cache
649 	 * flush is needed only for conventional zone files.
650 	 */
651 	if (ZONEFS_I(inode)->i_ztype == ZONEFS_ZTYPE_CNV)
652 		ret = file_write_and_wait_range(file, start, end);
653 	if (!ret)
654 		ret = blkdev_issue_flush(inode->i_sb->s_bdev);
655 
656 	if (ret)
657 		zonefs_io_error(inode, true);
658 
659 	return ret;
660 }
661 
662 static vm_fault_t zonefs_filemap_page_mkwrite(struct vm_fault *vmf)
663 {
664 	struct inode *inode = file_inode(vmf->vma->vm_file);
665 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
666 	vm_fault_t ret;
667 
668 	if (unlikely(IS_IMMUTABLE(inode)))
669 		return VM_FAULT_SIGBUS;
670 
671 	/*
672 	 * Sanity check: only conventional zone files can have shared
673 	 * writeable mappings.
674 	 */
675 	if (WARN_ON_ONCE(zi->i_ztype != ZONEFS_ZTYPE_CNV))
676 		return VM_FAULT_NOPAGE;
677 
678 	sb_start_pagefault(inode->i_sb);
679 	file_update_time(vmf->vma->vm_file);
680 
681 	/* Serialize against truncates */
682 	filemap_invalidate_lock_shared(inode->i_mapping);
683 	ret = iomap_page_mkwrite(vmf, &zonefs_write_iomap_ops);
684 	filemap_invalidate_unlock_shared(inode->i_mapping);
685 
686 	sb_end_pagefault(inode->i_sb);
687 	return ret;
688 }
689 
690 static const struct vm_operations_struct zonefs_file_vm_ops = {
691 	.fault		= filemap_fault,
692 	.map_pages	= filemap_map_pages,
693 	.page_mkwrite	= zonefs_filemap_page_mkwrite,
694 };
695 
696 static int zonefs_file_mmap(struct file *file, struct vm_area_struct *vma)
697 {
698 	/*
699 	 * Conventional zones accept random writes, so their files can support
700 	 * shared writable mappings. For sequential zone files, only read
701 	 * mappings are possible since there are no guarantees for write
702 	 * ordering between msync() and page cache writeback.
703 	 */
704 	if (ZONEFS_I(file_inode(file))->i_ztype == ZONEFS_ZTYPE_SEQ &&
705 	    (vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
706 		return -EINVAL;
707 
708 	file_accessed(file);
709 	vma->vm_ops = &zonefs_file_vm_ops;
710 
711 	return 0;
712 }
713 
714 static loff_t zonefs_file_llseek(struct file *file, loff_t offset, int whence)
715 {
716 	loff_t isize = i_size_read(file_inode(file));
717 
718 	/*
719 	 * Seeks are limited to below the zone size for conventional zones
720 	 * and below the zone write pointer for sequential zones. In both
721 	 * cases, this limit is the inode size.
722 	 */
723 	return generic_file_llseek_size(file, offset, whence, isize, isize);
724 }
725 
726 static int zonefs_file_write_dio_end_io(struct kiocb *iocb, ssize_t size,
727 					int error, unsigned int flags)
728 {
729 	struct inode *inode = file_inode(iocb->ki_filp);
730 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
731 
732 	if (error) {
733 		zonefs_io_error(inode, true);
734 		return error;
735 	}
736 
737 	if (size && zi->i_ztype != ZONEFS_ZTYPE_CNV) {
738 		/*
739 		 * Note that we may be seeing completions out of order,
740 		 * but that is not a problem since a write completed
741 		 * successfully necessarily means that all preceding writes
742 		 * were also successful. So we can safely increase the inode
743 		 * size to the write end location.
744 		 */
745 		mutex_lock(&zi->i_truncate_mutex);
746 		if (i_size_read(inode) < iocb->ki_pos + size) {
747 			zonefs_update_stats(inode, iocb->ki_pos + size);
748 			zonefs_i_size_write(inode, iocb->ki_pos + size);
749 		}
750 		mutex_unlock(&zi->i_truncate_mutex);
751 	}
752 
753 	return 0;
754 }
755 
756 static const struct iomap_dio_ops zonefs_write_dio_ops = {
757 	.end_io			= zonefs_file_write_dio_end_io,
758 };
759 
760 static ssize_t zonefs_file_dio_append(struct kiocb *iocb, struct iov_iter *from)
761 {
762 	struct inode *inode = file_inode(iocb->ki_filp);
763 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
764 	struct block_device *bdev = inode->i_sb->s_bdev;
765 	unsigned int max = bdev_max_zone_append_sectors(bdev);
766 	struct bio *bio;
767 	ssize_t size;
768 	int nr_pages;
769 	ssize_t ret;
770 
771 	max = ALIGN_DOWN(max << SECTOR_SHIFT, inode->i_sb->s_blocksize);
772 	iov_iter_truncate(from, max);
773 
774 	nr_pages = iov_iter_npages(from, BIO_MAX_VECS);
775 	if (!nr_pages)
776 		return 0;
777 
778 	bio = bio_alloc(bdev, nr_pages,
779 			REQ_OP_ZONE_APPEND | REQ_SYNC | REQ_IDLE, GFP_NOFS);
780 	bio->bi_iter.bi_sector = zi->i_zsector;
781 	bio->bi_ioprio = iocb->ki_ioprio;
782 	if (iocb_is_dsync(iocb))
783 		bio->bi_opf |= REQ_FUA;
784 
785 	ret = bio_iov_iter_get_pages(bio, from);
786 	if (unlikely(ret))
787 		goto out_release;
788 
789 	size = bio->bi_iter.bi_size;
790 	task_io_account_write(size);
791 
792 	if (iocb->ki_flags & IOCB_HIPRI)
793 		bio_set_polled(bio, iocb);
794 
795 	ret = submit_bio_wait(bio);
796 
797 	zonefs_file_write_dio_end_io(iocb, size, ret, 0);
798 	trace_zonefs_file_dio_append(inode, size, ret);
799 
800 out_release:
801 	bio_release_pages(bio, false);
802 	bio_put(bio);
803 
804 	if (ret >= 0) {
805 		iocb->ki_pos += size;
806 		return size;
807 	}
808 
809 	return ret;
810 }
811 
812 /*
813  * Do not exceed the LFS limits nor the file zone size. If pos is under the
814  * limit it becomes a short access. If it exceeds the limit, return -EFBIG.
815  */
816 static loff_t zonefs_write_check_limits(struct file *file, loff_t pos,
817 					loff_t count)
818 {
819 	struct inode *inode = file_inode(file);
820 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
821 	loff_t limit = rlimit(RLIMIT_FSIZE);
822 	loff_t max_size = zi->i_max_size;
823 
824 	if (limit != RLIM_INFINITY) {
825 		if (pos >= limit) {
826 			send_sig(SIGXFSZ, current, 0);
827 			return -EFBIG;
828 		}
829 		count = min(count, limit - pos);
830 	}
831 
832 	if (!(file->f_flags & O_LARGEFILE))
833 		max_size = min_t(loff_t, MAX_NON_LFS, max_size);
834 
835 	if (unlikely(pos >= max_size))
836 		return -EFBIG;
837 
838 	return min(count, max_size - pos);
839 }
840 
841 static ssize_t zonefs_write_checks(struct kiocb *iocb, struct iov_iter *from)
842 {
843 	struct file *file = iocb->ki_filp;
844 	struct inode *inode = file_inode(file);
845 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
846 	loff_t count;
847 
848 	if (IS_SWAPFILE(inode))
849 		return -ETXTBSY;
850 
851 	if (!iov_iter_count(from))
852 		return 0;
853 
854 	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
855 		return -EINVAL;
856 
857 	if (iocb->ki_flags & IOCB_APPEND) {
858 		if (zi->i_ztype != ZONEFS_ZTYPE_SEQ)
859 			return -EINVAL;
860 		mutex_lock(&zi->i_truncate_mutex);
861 		iocb->ki_pos = zi->i_wpoffset;
862 		mutex_unlock(&zi->i_truncate_mutex);
863 	}
864 
865 	count = zonefs_write_check_limits(file, iocb->ki_pos,
866 					  iov_iter_count(from));
867 	if (count < 0)
868 		return count;
869 
870 	iov_iter_truncate(from, count);
871 	return iov_iter_count(from);
872 }
873 
874 /*
875  * Handle direct writes. For sequential zone files, this is the only possible
876  * write path. For these files, check that the user is issuing writes
877  * sequentially from the end of the file. This code assumes that the block layer
878  * delivers write requests to the device in sequential order. This is always the
879  * case if a block IO scheduler implementing the ELEVATOR_F_ZBD_SEQ_WRITE
880  * elevator feature is being used (e.g. mq-deadline). The block layer always
881  * automatically select such an elevator for zoned block devices during the
882  * device initialization.
883  */
884 static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
885 {
886 	struct inode *inode = file_inode(iocb->ki_filp);
887 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
888 	struct super_block *sb = inode->i_sb;
889 	bool sync = is_sync_kiocb(iocb);
890 	bool append = false;
891 	ssize_t ret, count;
892 
893 	/*
894 	 * For async direct IOs to sequential zone files, refuse IOCB_NOWAIT
895 	 * as this can cause write reordering (e.g. the first aio gets EAGAIN
896 	 * on the inode lock but the second goes through but is now unaligned).
897 	 */
898 	if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && !sync &&
899 	    (iocb->ki_flags & IOCB_NOWAIT))
900 		return -EOPNOTSUPP;
901 
902 	if (iocb->ki_flags & IOCB_NOWAIT) {
903 		if (!inode_trylock(inode))
904 			return -EAGAIN;
905 	} else {
906 		inode_lock(inode);
907 	}
908 
909 	count = zonefs_write_checks(iocb, from);
910 	if (count <= 0) {
911 		ret = count;
912 		goto inode_unlock;
913 	}
914 
915 	if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
916 		ret = -EINVAL;
917 		goto inode_unlock;
918 	}
919 
920 	/* Enforce sequential writes (append only) in sequential zones */
921 	if (zi->i_ztype == ZONEFS_ZTYPE_SEQ) {
922 		mutex_lock(&zi->i_truncate_mutex);
923 		if (iocb->ki_pos != zi->i_wpoffset) {
924 			mutex_unlock(&zi->i_truncate_mutex);
925 			ret = -EINVAL;
926 			goto inode_unlock;
927 		}
928 		mutex_unlock(&zi->i_truncate_mutex);
929 		append = sync;
930 	}
931 
932 	if (append)
933 		ret = zonefs_file_dio_append(iocb, from);
934 	else
935 		ret = iomap_dio_rw(iocb, from, &zonefs_write_iomap_ops,
936 				   &zonefs_write_dio_ops, 0, NULL, 0);
937 	if (zi->i_ztype == ZONEFS_ZTYPE_SEQ &&
938 	    (ret > 0 || ret == -EIOCBQUEUED)) {
939 		if (ret > 0)
940 			count = ret;
941 
942 		/*
943 		 * Update the zone write pointer offset assuming the write
944 		 * operation succeeded. If it did not, the error recovery path
945 		 * will correct it. Also do active seq file accounting.
946 		 */
947 		mutex_lock(&zi->i_truncate_mutex);
948 		zi->i_wpoffset += count;
949 		zonefs_account_active(inode);
950 		mutex_unlock(&zi->i_truncate_mutex);
951 	}
952 
953 inode_unlock:
954 	inode_unlock(inode);
955 
956 	return ret;
957 }
958 
959 static ssize_t zonefs_file_buffered_write(struct kiocb *iocb,
960 					  struct iov_iter *from)
961 {
962 	struct inode *inode = file_inode(iocb->ki_filp);
963 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
964 	ssize_t ret;
965 
966 	/*
967 	 * Direct IO writes are mandatory for sequential zone files so that the
968 	 * write IO issuing order is preserved.
969 	 */
970 	if (zi->i_ztype != ZONEFS_ZTYPE_CNV)
971 		return -EIO;
972 
973 	if (iocb->ki_flags & IOCB_NOWAIT) {
974 		if (!inode_trylock(inode))
975 			return -EAGAIN;
976 	} else {
977 		inode_lock(inode);
978 	}
979 
980 	ret = zonefs_write_checks(iocb, from);
981 	if (ret <= 0)
982 		goto inode_unlock;
983 
984 	ret = iomap_file_buffered_write(iocb, from, &zonefs_write_iomap_ops);
985 	if (ret > 0)
986 		iocb->ki_pos += ret;
987 	else if (ret == -EIO)
988 		zonefs_io_error(inode, true);
989 
990 inode_unlock:
991 	inode_unlock(inode);
992 	if (ret > 0)
993 		ret = generic_write_sync(iocb, ret);
994 
995 	return ret;
996 }
997 
998 static ssize_t zonefs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
999 {
1000 	struct inode *inode = file_inode(iocb->ki_filp);
1001 
1002 	if (unlikely(IS_IMMUTABLE(inode)))
1003 		return -EPERM;
1004 
1005 	if (sb_rdonly(inode->i_sb))
1006 		return -EROFS;
1007 
1008 	/* Write operations beyond the zone size are not allowed */
1009 	if (iocb->ki_pos >= ZONEFS_I(inode)->i_max_size)
1010 		return -EFBIG;
1011 
1012 	if (iocb->ki_flags & IOCB_DIRECT) {
1013 		ssize_t ret = zonefs_file_dio_write(iocb, from);
1014 		if (ret != -ENOTBLK)
1015 			return ret;
1016 	}
1017 
1018 	return zonefs_file_buffered_write(iocb, from);
1019 }
1020 
1021 static int zonefs_file_read_dio_end_io(struct kiocb *iocb, ssize_t size,
1022 				       int error, unsigned int flags)
1023 {
1024 	if (error) {
1025 		zonefs_io_error(file_inode(iocb->ki_filp), false);
1026 		return error;
1027 	}
1028 
1029 	return 0;
1030 }
1031 
1032 static const struct iomap_dio_ops zonefs_read_dio_ops = {
1033 	.end_io			= zonefs_file_read_dio_end_io,
1034 };
1035 
1036 static ssize_t zonefs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
1037 {
1038 	struct inode *inode = file_inode(iocb->ki_filp);
1039 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
1040 	struct super_block *sb = inode->i_sb;
1041 	loff_t isize;
1042 	ssize_t ret;
1043 
1044 	/* Offline zones cannot be read */
1045 	if (unlikely(IS_IMMUTABLE(inode) && !(inode->i_mode & 0777)))
1046 		return -EPERM;
1047 
1048 	if (iocb->ki_pos >= zi->i_max_size)
1049 		return 0;
1050 
1051 	if (iocb->ki_flags & IOCB_NOWAIT) {
1052 		if (!inode_trylock_shared(inode))
1053 			return -EAGAIN;
1054 	} else {
1055 		inode_lock_shared(inode);
1056 	}
1057 
1058 	/* Limit read operations to written data */
1059 	mutex_lock(&zi->i_truncate_mutex);
1060 	isize = i_size_read(inode);
1061 	if (iocb->ki_pos >= isize) {
1062 		mutex_unlock(&zi->i_truncate_mutex);
1063 		ret = 0;
1064 		goto inode_unlock;
1065 	}
1066 	iov_iter_truncate(to, isize - iocb->ki_pos);
1067 	mutex_unlock(&zi->i_truncate_mutex);
1068 
1069 	if (iocb->ki_flags & IOCB_DIRECT) {
1070 		size_t count = iov_iter_count(to);
1071 
1072 		if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
1073 			ret = -EINVAL;
1074 			goto inode_unlock;
1075 		}
1076 		file_accessed(iocb->ki_filp);
1077 		ret = iomap_dio_rw(iocb, to, &zonefs_read_iomap_ops,
1078 				   &zonefs_read_dio_ops, 0, NULL, 0);
1079 	} else {
1080 		ret = generic_file_read_iter(iocb, to);
1081 		if (ret == -EIO)
1082 			zonefs_io_error(inode, false);
1083 	}
1084 
1085 inode_unlock:
1086 	inode_unlock_shared(inode);
1087 
1088 	return ret;
1089 }
1090 
1091 /*
1092  * Write open accounting is done only for sequential files.
1093  */
1094 static inline bool zonefs_seq_file_need_wro(struct inode *inode,
1095 					    struct file *file)
1096 {
1097 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
1098 
1099 	if (zi->i_ztype != ZONEFS_ZTYPE_SEQ)
1100 		return false;
1101 
1102 	if (!(file->f_mode & FMODE_WRITE))
1103 		return false;
1104 
1105 	return true;
1106 }
1107 
1108 static int zonefs_seq_file_write_open(struct inode *inode)
1109 {
1110 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
1111 	int ret = 0;
1112 
1113 	mutex_lock(&zi->i_truncate_mutex);
1114 
1115 	if (!zi->i_wr_refcnt) {
1116 		struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
1117 		unsigned int wro = atomic_inc_return(&sbi->s_wro_seq_files);
1118 
1119 		if (sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) {
1120 
1121 			if (sbi->s_max_wro_seq_files
1122 			    && wro > sbi->s_max_wro_seq_files) {
1123 				atomic_dec(&sbi->s_wro_seq_files);
1124 				ret = -EBUSY;
1125 				goto unlock;
1126 			}
1127 
1128 			if (i_size_read(inode) < zi->i_max_size) {
1129 				ret = zonefs_zone_mgmt(inode, REQ_OP_ZONE_OPEN);
1130 				if (ret) {
1131 					atomic_dec(&sbi->s_wro_seq_files);
1132 					goto unlock;
1133 				}
1134 				zi->i_flags |= ZONEFS_ZONE_OPEN;
1135 				zonefs_account_active(inode);
1136 			}
1137 		}
1138 	}
1139 
1140 	zi->i_wr_refcnt++;
1141 
1142 unlock:
1143 	mutex_unlock(&zi->i_truncate_mutex);
1144 
1145 	return ret;
1146 }
1147 
1148 static int zonefs_file_open(struct inode *inode, struct file *file)
1149 {
1150 	int ret;
1151 
1152 	ret = generic_file_open(inode, file);
1153 	if (ret)
1154 		return ret;
1155 
1156 	if (zonefs_seq_file_need_wro(inode, file))
1157 		return zonefs_seq_file_write_open(inode);
1158 
1159 	return 0;
1160 }
1161 
1162 static void zonefs_seq_file_write_close(struct inode *inode)
1163 {
1164 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
1165 	struct super_block *sb = inode->i_sb;
1166 	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1167 	int ret = 0;
1168 
1169 	mutex_lock(&zi->i_truncate_mutex);
1170 
1171 	zi->i_wr_refcnt--;
1172 	if (zi->i_wr_refcnt)
1173 		goto unlock;
1174 
1175 	/*
1176 	 * The file zone may not be open anymore (e.g. the file was truncated to
1177 	 * its maximum size or it was fully written). For this case, we only
1178 	 * need to decrement the write open count.
1179 	 */
1180 	if (zi->i_flags & ZONEFS_ZONE_OPEN) {
1181 		ret = zonefs_zone_mgmt(inode, REQ_OP_ZONE_CLOSE);
1182 		if (ret) {
1183 			__zonefs_io_error(inode, false);
1184 			/*
1185 			 * Leaving zones explicitly open may lead to a state
1186 			 * where most zones cannot be written (zone resources
1187 			 * exhausted). So take preventive action by remounting
1188 			 * read-only.
1189 			 */
1190 			if (zi->i_flags & ZONEFS_ZONE_OPEN &&
1191 			    !(sb->s_flags & SB_RDONLY)) {
1192 				zonefs_warn(sb,
1193 					"closing zone at %llu failed %d\n",
1194 					zi->i_zsector, ret);
1195 				zonefs_warn(sb,
1196 					"remounting filesystem read-only\n");
1197 				sb->s_flags |= SB_RDONLY;
1198 			}
1199 			goto unlock;
1200 		}
1201 
1202 		zi->i_flags &= ~ZONEFS_ZONE_OPEN;
1203 		zonefs_account_active(inode);
1204 	}
1205 
1206 	atomic_dec(&sbi->s_wro_seq_files);
1207 
1208 unlock:
1209 	mutex_unlock(&zi->i_truncate_mutex);
1210 }
1211 
1212 static int zonefs_file_release(struct inode *inode, struct file *file)
1213 {
1214 	/*
1215 	 * If we explicitly open a zone we must close it again as well, but the
1216 	 * zone management operation can fail (either due to an IO error or as
1217 	 * the zone has gone offline or read-only). Make sure we don't fail the
1218 	 * close(2) for user-space.
1219 	 */
1220 	if (zonefs_seq_file_need_wro(inode, file))
1221 		zonefs_seq_file_write_close(inode);
1222 
1223 	return 0;
1224 }
1225 
1226 static const struct file_operations zonefs_file_operations = {
1227 	.open		= zonefs_file_open,
1228 	.release	= zonefs_file_release,
1229 	.fsync		= zonefs_file_fsync,
1230 	.mmap		= zonefs_file_mmap,
1231 	.llseek		= zonefs_file_llseek,
1232 	.read_iter	= zonefs_file_read_iter,
1233 	.write_iter	= zonefs_file_write_iter,
1234 	.splice_read	= generic_file_splice_read,
1235 	.splice_write	= iter_file_splice_write,
1236 	.iopoll		= iocb_bio_iopoll,
1237 };
1238 
1239 static struct kmem_cache *zonefs_inode_cachep;
1240 
1241 static struct inode *zonefs_alloc_inode(struct super_block *sb)
1242 {
1243 	struct zonefs_inode_info *zi;
1244 
1245 	zi = alloc_inode_sb(sb, zonefs_inode_cachep, GFP_KERNEL);
1246 	if (!zi)
1247 		return NULL;
1248 
1249 	inode_init_once(&zi->i_vnode);
1250 	mutex_init(&zi->i_truncate_mutex);
1251 	zi->i_wr_refcnt = 0;
1252 	zi->i_flags = 0;
1253 
1254 	return &zi->i_vnode;
1255 }
1256 
1257 static void zonefs_free_inode(struct inode *inode)
1258 {
1259 	kmem_cache_free(zonefs_inode_cachep, ZONEFS_I(inode));
1260 }
1261 
1262 /*
1263  * File system stat.
1264  */
1265 static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf)
1266 {
1267 	struct super_block *sb = dentry->d_sb;
1268 	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1269 	enum zonefs_ztype t;
1270 
1271 	buf->f_type = ZONEFS_MAGIC;
1272 	buf->f_bsize = sb->s_blocksize;
1273 	buf->f_namelen = ZONEFS_NAME_MAX;
1274 
1275 	spin_lock(&sbi->s_lock);
1276 
1277 	buf->f_blocks = sbi->s_blocks;
1278 	if (WARN_ON(sbi->s_used_blocks > sbi->s_blocks))
1279 		buf->f_bfree = 0;
1280 	else
1281 		buf->f_bfree = buf->f_blocks - sbi->s_used_blocks;
1282 	buf->f_bavail = buf->f_bfree;
1283 
1284 	for (t = 0; t < ZONEFS_ZTYPE_MAX; t++) {
1285 		if (sbi->s_nr_files[t])
1286 			buf->f_files += sbi->s_nr_files[t] + 1;
1287 	}
1288 	buf->f_ffree = 0;
1289 
1290 	spin_unlock(&sbi->s_lock);
1291 
1292 	buf->f_fsid = uuid_to_fsid(sbi->s_uuid.b);
1293 
1294 	return 0;
1295 }
1296 
1297 enum {
1298 	Opt_errors_ro, Opt_errors_zro, Opt_errors_zol, Opt_errors_repair,
1299 	Opt_explicit_open, Opt_err,
1300 };
1301 
1302 static const match_table_t tokens = {
1303 	{ Opt_errors_ro,	"errors=remount-ro"},
1304 	{ Opt_errors_zro,	"errors=zone-ro"},
1305 	{ Opt_errors_zol,	"errors=zone-offline"},
1306 	{ Opt_errors_repair,	"errors=repair"},
1307 	{ Opt_explicit_open,	"explicit-open" },
1308 	{ Opt_err,		NULL}
1309 };
1310 
1311 static int zonefs_parse_options(struct super_block *sb, char *options)
1312 {
1313 	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1314 	substring_t args[MAX_OPT_ARGS];
1315 	char *p;
1316 
1317 	if (!options)
1318 		return 0;
1319 
1320 	while ((p = strsep(&options, ",")) != NULL) {
1321 		int token;
1322 
1323 		if (!*p)
1324 			continue;
1325 
1326 		token = match_token(p, tokens, args);
1327 		switch (token) {
1328 		case Opt_errors_ro:
1329 			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
1330 			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_RO;
1331 			break;
1332 		case Opt_errors_zro:
1333 			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
1334 			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_ZRO;
1335 			break;
1336 		case Opt_errors_zol:
1337 			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
1338 			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_ZOL;
1339 			break;
1340 		case Opt_errors_repair:
1341 			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
1342 			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_REPAIR;
1343 			break;
1344 		case Opt_explicit_open:
1345 			sbi->s_mount_opts |= ZONEFS_MNTOPT_EXPLICIT_OPEN;
1346 			break;
1347 		default:
1348 			return -EINVAL;
1349 		}
1350 	}
1351 
1352 	return 0;
1353 }
1354 
1355 static int zonefs_show_options(struct seq_file *seq, struct dentry *root)
1356 {
1357 	struct zonefs_sb_info *sbi = ZONEFS_SB(root->d_sb);
1358 
1359 	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO)
1360 		seq_puts(seq, ",errors=remount-ro");
1361 	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO)
1362 		seq_puts(seq, ",errors=zone-ro");
1363 	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL)
1364 		seq_puts(seq, ",errors=zone-offline");
1365 	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_REPAIR)
1366 		seq_puts(seq, ",errors=repair");
1367 
1368 	return 0;
1369 }
1370 
1371 static int zonefs_remount(struct super_block *sb, int *flags, char *data)
1372 {
1373 	sync_filesystem(sb);
1374 
1375 	return zonefs_parse_options(sb, data);
1376 }
1377 
1378 static const struct super_operations zonefs_sops = {
1379 	.alloc_inode	= zonefs_alloc_inode,
1380 	.free_inode	= zonefs_free_inode,
1381 	.statfs		= zonefs_statfs,
1382 	.remount_fs	= zonefs_remount,
1383 	.show_options	= zonefs_show_options,
1384 };
1385 
1386 static const struct inode_operations zonefs_dir_inode_operations = {
1387 	.lookup		= simple_lookup,
1388 	.setattr	= zonefs_inode_setattr,
1389 };
1390 
1391 static void zonefs_init_dir_inode(struct inode *parent, struct inode *inode,
1392 				  enum zonefs_ztype type)
1393 {
1394 	struct super_block *sb = parent->i_sb;
1395 
1396 	inode->i_ino = bdev_nr_zones(sb->s_bdev) + type + 1;
1397 	inode_init_owner(&init_user_ns, inode, parent, S_IFDIR | 0555);
1398 	inode->i_op = &zonefs_dir_inode_operations;
1399 	inode->i_fop = &simple_dir_operations;
1400 	set_nlink(inode, 2);
1401 	inc_nlink(parent);
1402 }
1403 
1404 static int zonefs_init_file_inode(struct inode *inode, struct blk_zone *zone,
1405 				  enum zonefs_ztype type)
1406 {
1407 	struct super_block *sb = inode->i_sb;
1408 	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1409 	struct zonefs_inode_info *zi = ZONEFS_I(inode);
1410 	int ret = 0;
1411 
1412 	inode->i_ino = zone->start >> sbi->s_zone_sectors_shift;
1413 	inode->i_mode = S_IFREG | sbi->s_perm;
1414 
1415 	zi->i_ztype = type;
1416 	zi->i_zsector = zone->start;
1417 	zi->i_zone_size = zone->len << SECTOR_SHIFT;
1418 
1419 	zi->i_max_size = min_t(loff_t, MAX_LFS_FILESIZE,
1420 			       zone->capacity << SECTOR_SHIFT);
1421 	zi->i_wpoffset = zonefs_check_zone_condition(inode, zone, true, true);
1422 
1423 	inode->i_uid = sbi->s_uid;
1424 	inode->i_gid = sbi->s_gid;
1425 	inode->i_size = zi->i_wpoffset;
1426 	inode->i_blocks = zi->i_max_size >> SECTOR_SHIFT;
1427 
1428 	inode->i_op = &zonefs_file_inode_operations;
1429 	inode->i_fop = &zonefs_file_operations;
1430 	inode->i_mapping->a_ops = &zonefs_file_aops;
1431 
1432 	sb->s_maxbytes = max(zi->i_max_size, sb->s_maxbytes);
1433 	sbi->s_blocks += zi->i_max_size >> sb->s_blocksize_bits;
1434 	sbi->s_used_blocks += zi->i_wpoffset >> sb->s_blocksize_bits;
1435 
1436 	mutex_lock(&zi->i_truncate_mutex);
1437 
1438 	/*
1439 	 * For sequential zones, make sure that any open zone is closed first
1440 	 * to ensure that the initial number of open zones is 0, in sync with
1441 	 * the open zone accounting done when the mount option
1442 	 * ZONEFS_MNTOPT_EXPLICIT_OPEN is used.
1443 	 */
1444 	if (type == ZONEFS_ZTYPE_SEQ &&
1445 	    (zone->cond == BLK_ZONE_COND_IMP_OPEN ||
1446 	     zone->cond == BLK_ZONE_COND_EXP_OPEN)) {
1447 		ret = zonefs_zone_mgmt(inode, REQ_OP_ZONE_CLOSE);
1448 		if (ret)
1449 			goto unlock;
1450 	}
1451 
1452 	zonefs_account_active(inode);
1453 
1454 unlock:
1455 	mutex_unlock(&zi->i_truncate_mutex);
1456 
1457 	return ret;
1458 }
1459 
1460 static struct dentry *zonefs_create_inode(struct dentry *parent,
1461 					const char *name, struct blk_zone *zone,
1462 					enum zonefs_ztype type)
1463 {
1464 	struct inode *dir = d_inode(parent);
1465 	struct dentry *dentry;
1466 	struct inode *inode;
1467 	int ret;
1468 
1469 	dentry = d_alloc_name(parent, name);
1470 	if (!dentry)
1471 		return NULL;
1472 
1473 	inode = new_inode(parent->d_sb);
1474 	if (!inode)
1475 		goto dput;
1476 
1477 	inode->i_ctime = inode->i_mtime = inode->i_atime = dir->i_ctime;
1478 	if (zone) {
1479 		ret = zonefs_init_file_inode(inode, zone, type);
1480 		if (ret) {
1481 			iput(inode);
1482 			goto dput;
1483 		}
1484 	} else {
1485 		zonefs_init_dir_inode(dir, inode, type);
1486 	}
1487 
1488 	d_add(dentry, inode);
1489 	dir->i_size++;
1490 
1491 	return dentry;
1492 
1493 dput:
1494 	dput(dentry);
1495 
1496 	return NULL;
1497 }
1498 
1499 struct zonefs_zone_data {
1500 	struct super_block	*sb;
1501 	unsigned int		nr_zones[ZONEFS_ZTYPE_MAX];
1502 	struct blk_zone		*zones;
1503 };
1504 
1505 /*
1506  * Create a zone group and populate it with zone files.
1507  */
1508 static int zonefs_create_zgroup(struct zonefs_zone_data *zd,
1509 				enum zonefs_ztype type)
1510 {
1511 	struct super_block *sb = zd->sb;
1512 	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1513 	struct blk_zone *zone, *next, *end;
1514 	const char *zgroup_name;
1515 	char *file_name;
1516 	struct dentry *dir;
1517 	unsigned int n = 0;
1518 	int ret;
1519 
1520 	/* If the group is empty, there is nothing to do */
1521 	if (!zd->nr_zones[type])
1522 		return 0;
1523 
1524 	file_name = kmalloc(ZONEFS_NAME_MAX, GFP_KERNEL);
1525 	if (!file_name)
1526 		return -ENOMEM;
1527 
1528 	if (type == ZONEFS_ZTYPE_CNV)
1529 		zgroup_name = "cnv";
1530 	else
1531 		zgroup_name = "seq";
1532 
1533 	dir = zonefs_create_inode(sb->s_root, zgroup_name, NULL, type);
1534 	if (!dir) {
1535 		ret = -ENOMEM;
1536 		goto free;
1537 	}
1538 
1539 	/*
1540 	 * The first zone contains the super block: skip it.
1541 	 */
1542 	end = zd->zones + bdev_nr_zones(sb->s_bdev);
1543 	for (zone = &zd->zones[1]; zone < end; zone = next) {
1544 
1545 		next = zone + 1;
1546 		if (zonefs_zone_type(zone) != type)
1547 			continue;
1548 
1549 		/*
1550 		 * For conventional zones, contiguous zones can be aggregated
1551 		 * together to form larger files. Note that this overwrites the
1552 		 * length of the first zone of the set of contiguous zones
1553 		 * aggregated together. If one offline or read-only zone is
1554 		 * found, assume that all zones aggregated have the same
1555 		 * condition.
1556 		 */
1557 		if (type == ZONEFS_ZTYPE_CNV &&
1558 		    (sbi->s_features & ZONEFS_F_AGGRCNV)) {
1559 			for (; next < end; next++) {
1560 				if (zonefs_zone_type(next) != type)
1561 					break;
1562 				zone->len += next->len;
1563 				zone->capacity += next->capacity;
1564 				if (next->cond == BLK_ZONE_COND_READONLY &&
1565 				    zone->cond != BLK_ZONE_COND_OFFLINE)
1566 					zone->cond = BLK_ZONE_COND_READONLY;
1567 				else if (next->cond == BLK_ZONE_COND_OFFLINE)
1568 					zone->cond = BLK_ZONE_COND_OFFLINE;
1569 			}
1570 			if (zone->capacity != zone->len) {
1571 				zonefs_err(sb, "Invalid conventional zone capacity\n");
1572 				ret = -EINVAL;
1573 				goto free;
1574 			}
1575 		}
1576 
1577 		/*
1578 		 * Use the file number within its group as file name.
1579 		 */
1580 		snprintf(file_name, ZONEFS_NAME_MAX - 1, "%u", n);
1581 		if (!zonefs_create_inode(dir, file_name, zone, type)) {
1582 			ret = -ENOMEM;
1583 			goto free;
1584 		}
1585 
1586 		n++;
1587 	}
1588 
1589 	zonefs_info(sb, "Zone group \"%s\" has %u file%s\n",
1590 		    zgroup_name, n, n > 1 ? "s" : "");
1591 
1592 	sbi->s_nr_files[type] = n;
1593 	ret = 0;
1594 
1595 free:
1596 	kfree(file_name);
1597 
1598 	return ret;
1599 }
1600 
1601 static int zonefs_get_zone_info_cb(struct blk_zone *zone, unsigned int idx,
1602 				   void *data)
1603 {
1604 	struct zonefs_zone_data *zd = data;
1605 
1606 	/*
1607 	 * Count the number of usable zones: the first zone at index 0 contains
1608 	 * the super block and is ignored.
1609 	 */
1610 	switch (zone->type) {
1611 	case BLK_ZONE_TYPE_CONVENTIONAL:
1612 		zone->wp = zone->start + zone->len;
1613 		if (idx)
1614 			zd->nr_zones[ZONEFS_ZTYPE_CNV]++;
1615 		break;
1616 	case BLK_ZONE_TYPE_SEQWRITE_REQ:
1617 	case BLK_ZONE_TYPE_SEQWRITE_PREF:
1618 		if (idx)
1619 			zd->nr_zones[ZONEFS_ZTYPE_SEQ]++;
1620 		break;
1621 	default:
1622 		zonefs_err(zd->sb, "Unsupported zone type 0x%x\n",
1623 			   zone->type);
1624 		return -EIO;
1625 	}
1626 
1627 	memcpy(&zd->zones[idx], zone, sizeof(struct blk_zone));
1628 
1629 	return 0;
1630 }
1631 
1632 static int zonefs_get_zone_info(struct zonefs_zone_data *zd)
1633 {
1634 	struct block_device *bdev = zd->sb->s_bdev;
1635 	int ret;
1636 
1637 	zd->zones = kvcalloc(bdev_nr_zones(bdev), sizeof(struct blk_zone),
1638 			     GFP_KERNEL);
1639 	if (!zd->zones)
1640 		return -ENOMEM;
1641 
1642 	/* Get zones information from the device */
1643 	ret = blkdev_report_zones(bdev, 0, BLK_ALL_ZONES,
1644 				  zonefs_get_zone_info_cb, zd);
1645 	if (ret < 0) {
1646 		zonefs_err(zd->sb, "Zone report failed %d\n", ret);
1647 		return ret;
1648 	}
1649 
1650 	if (ret != bdev_nr_zones(bdev)) {
1651 		zonefs_err(zd->sb, "Invalid zone report (%d/%u zones)\n",
1652 			   ret, bdev_nr_zones(bdev));
1653 		return -EIO;
1654 	}
1655 
1656 	return 0;
1657 }
1658 
1659 static inline void zonefs_cleanup_zone_info(struct zonefs_zone_data *zd)
1660 {
1661 	kvfree(zd->zones);
1662 }
1663 
1664 /*
1665  * Read super block information from the device.
1666  */
1667 static int zonefs_read_super(struct super_block *sb)
1668 {
1669 	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1670 	struct zonefs_super *super;
1671 	u32 crc, stored_crc;
1672 	struct page *page;
1673 	struct bio_vec bio_vec;
1674 	struct bio bio;
1675 	int ret;
1676 
1677 	page = alloc_page(GFP_KERNEL);
1678 	if (!page)
1679 		return -ENOMEM;
1680 
1681 	bio_init(&bio, sb->s_bdev, &bio_vec, 1, REQ_OP_READ);
1682 	bio.bi_iter.bi_sector = 0;
1683 	bio_add_page(&bio, page, PAGE_SIZE, 0);
1684 
1685 	ret = submit_bio_wait(&bio);
1686 	if (ret)
1687 		goto free_page;
1688 
1689 	super = page_address(page);
1690 
1691 	ret = -EINVAL;
1692 	if (le32_to_cpu(super->s_magic) != ZONEFS_MAGIC)
1693 		goto free_page;
1694 
1695 	stored_crc = le32_to_cpu(super->s_crc);
1696 	super->s_crc = 0;
1697 	crc = crc32(~0U, (unsigned char *)super, sizeof(struct zonefs_super));
1698 	if (crc != stored_crc) {
1699 		zonefs_err(sb, "Invalid checksum (Expected 0x%08x, got 0x%08x)",
1700 			   crc, stored_crc);
1701 		goto free_page;
1702 	}
1703 
1704 	sbi->s_features = le64_to_cpu(super->s_features);
1705 	if (sbi->s_features & ~ZONEFS_F_DEFINED_FEATURES) {
1706 		zonefs_err(sb, "Unknown features set 0x%llx\n",
1707 			   sbi->s_features);
1708 		goto free_page;
1709 	}
1710 
1711 	if (sbi->s_features & ZONEFS_F_UID) {
1712 		sbi->s_uid = make_kuid(current_user_ns(),
1713 				       le32_to_cpu(super->s_uid));
1714 		if (!uid_valid(sbi->s_uid)) {
1715 			zonefs_err(sb, "Invalid UID feature\n");
1716 			goto free_page;
1717 		}
1718 	}
1719 
1720 	if (sbi->s_features & ZONEFS_F_GID) {
1721 		sbi->s_gid = make_kgid(current_user_ns(),
1722 				       le32_to_cpu(super->s_gid));
1723 		if (!gid_valid(sbi->s_gid)) {
1724 			zonefs_err(sb, "Invalid GID feature\n");
1725 			goto free_page;
1726 		}
1727 	}
1728 
1729 	if (sbi->s_features & ZONEFS_F_PERM)
1730 		sbi->s_perm = le32_to_cpu(super->s_perm);
1731 
1732 	if (memchr_inv(super->s_reserved, 0, sizeof(super->s_reserved))) {
1733 		zonefs_err(sb, "Reserved area is being used\n");
1734 		goto free_page;
1735 	}
1736 
1737 	import_uuid(&sbi->s_uuid, super->s_uuid);
1738 	ret = 0;
1739 
1740 free_page:
1741 	__free_page(page);
1742 
1743 	return ret;
1744 }
1745 
1746 /*
1747  * Check that the device is zoned. If it is, get the list of zones and create
1748  * sub-directories and files according to the device zone configuration and
1749  * format options.
1750  */
1751 static int zonefs_fill_super(struct super_block *sb, void *data, int silent)
1752 {
1753 	struct zonefs_zone_data zd;
1754 	struct zonefs_sb_info *sbi;
1755 	struct inode *inode;
1756 	enum zonefs_ztype t;
1757 	int ret;
1758 
1759 	if (!bdev_is_zoned(sb->s_bdev)) {
1760 		zonefs_err(sb, "Not a zoned block device\n");
1761 		return -EINVAL;
1762 	}
1763 
1764 	/*
1765 	 * Initialize super block information: the maximum file size is updated
1766 	 * when the zone files are created so that the format option
1767 	 * ZONEFS_F_AGGRCNV which increases the maximum file size of a file
1768 	 * beyond the zone size is taken into account.
1769 	 */
1770 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1771 	if (!sbi)
1772 		return -ENOMEM;
1773 
1774 	spin_lock_init(&sbi->s_lock);
1775 	sb->s_fs_info = sbi;
1776 	sb->s_magic = ZONEFS_MAGIC;
1777 	sb->s_maxbytes = 0;
1778 	sb->s_op = &zonefs_sops;
1779 	sb->s_time_gran	= 1;
1780 
1781 	/*
1782 	 * The block size is set to the device zone write granularity to ensure
1783 	 * that write operations are always aligned according to the device
1784 	 * interface constraints.
1785 	 */
1786 	sb_set_blocksize(sb, bdev_zone_write_granularity(sb->s_bdev));
1787 	sbi->s_zone_sectors_shift = ilog2(bdev_zone_sectors(sb->s_bdev));
1788 	sbi->s_uid = GLOBAL_ROOT_UID;
1789 	sbi->s_gid = GLOBAL_ROOT_GID;
1790 	sbi->s_perm = 0640;
1791 	sbi->s_mount_opts = ZONEFS_MNTOPT_ERRORS_RO;
1792 
1793 	atomic_set(&sbi->s_wro_seq_files, 0);
1794 	sbi->s_max_wro_seq_files = bdev_max_open_zones(sb->s_bdev);
1795 	atomic_set(&sbi->s_active_seq_files, 0);
1796 	sbi->s_max_active_seq_files = bdev_max_active_zones(sb->s_bdev);
1797 
1798 	ret = zonefs_read_super(sb);
1799 	if (ret)
1800 		return ret;
1801 
1802 	ret = zonefs_parse_options(sb, data);
1803 	if (ret)
1804 		return ret;
1805 
1806 	memset(&zd, 0, sizeof(struct zonefs_zone_data));
1807 	zd.sb = sb;
1808 	ret = zonefs_get_zone_info(&zd);
1809 	if (ret)
1810 		goto cleanup;
1811 
1812 	ret = zonefs_sysfs_register(sb);
1813 	if (ret)
1814 		goto cleanup;
1815 
1816 	zonefs_info(sb, "Mounting %u zones", bdev_nr_zones(sb->s_bdev));
1817 
1818 	if (!sbi->s_max_wro_seq_files &&
1819 	    !sbi->s_max_active_seq_files &&
1820 	    sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) {
1821 		zonefs_info(sb,
1822 			"No open and active zone limits. Ignoring explicit_open mount option\n");
1823 		sbi->s_mount_opts &= ~ZONEFS_MNTOPT_EXPLICIT_OPEN;
1824 	}
1825 
1826 	/* Create root directory inode */
1827 	ret = -ENOMEM;
1828 	inode = new_inode(sb);
1829 	if (!inode)
1830 		goto cleanup;
1831 
1832 	inode->i_ino = bdev_nr_zones(sb->s_bdev);
1833 	inode->i_mode = S_IFDIR | 0555;
1834 	inode->i_ctime = inode->i_mtime = inode->i_atime = current_time(inode);
1835 	inode->i_op = &zonefs_dir_inode_operations;
1836 	inode->i_fop = &simple_dir_operations;
1837 	set_nlink(inode, 2);
1838 
1839 	sb->s_root = d_make_root(inode);
1840 	if (!sb->s_root)
1841 		goto cleanup;
1842 
1843 	/* Create and populate files in zone groups directories */
1844 	for (t = 0; t < ZONEFS_ZTYPE_MAX; t++) {
1845 		ret = zonefs_create_zgroup(&zd, t);
1846 		if (ret)
1847 			break;
1848 	}
1849 
1850 cleanup:
1851 	zonefs_cleanup_zone_info(&zd);
1852 
1853 	return ret;
1854 }
1855 
1856 static struct dentry *zonefs_mount(struct file_system_type *fs_type,
1857 				   int flags, const char *dev_name, void *data)
1858 {
1859 	return mount_bdev(fs_type, flags, dev_name, data, zonefs_fill_super);
1860 }
1861 
1862 static void zonefs_kill_super(struct super_block *sb)
1863 {
1864 	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1865 
1866 	if (sb->s_root)
1867 		d_genocide(sb->s_root);
1868 
1869 	zonefs_sysfs_unregister(sb);
1870 	kill_block_super(sb);
1871 	kfree(sbi);
1872 }
1873 
1874 /*
1875  * File system definition and registration.
1876  */
1877 static struct file_system_type zonefs_type = {
1878 	.owner		= THIS_MODULE,
1879 	.name		= "zonefs",
1880 	.mount		= zonefs_mount,
1881 	.kill_sb	= zonefs_kill_super,
1882 	.fs_flags	= FS_REQUIRES_DEV,
1883 };
1884 
1885 static int __init zonefs_init_inodecache(void)
1886 {
1887 	zonefs_inode_cachep = kmem_cache_create("zonefs_inode_cache",
1888 			sizeof(struct zonefs_inode_info), 0,
1889 			(SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT),
1890 			NULL);
1891 	if (zonefs_inode_cachep == NULL)
1892 		return -ENOMEM;
1893 	return 0;
1894 }
1895 
1896 static void zonefs_destroy_inodecache(void)
1897 {
1898 	/*
1899 	 * Make sure all delayed rcu free inodes are flushed before we
1900 	 * destroy the inode cache.
1901 	 */
1902 	rcu_barrier();
1903 	kmem_cache_destroy(zonefs_inode_cachep);
1904 }
1905 
1906 static int __init zonefs_init(void)
1907 {
1908 	int ret;
1909 
1910 	BUILD_BUG_ON(sizeof(struct zonefs_super) != ZONEFS_SUPER_SIZE);
1911 
1912 	ret = zonefs_init_inodecache();
1913 	if (ret)
1914 		return ret;
1915 
1916 	ret = register_filesystem(&zonefs_type);
1917 	if (ret)
1918 		goto destroy_inodecache;
1919 
1920 	ret = zonefs_sysfs_init();
1921 	if (ret)
1922 		goto unregister_fs;
1923 
1924 	return 0;
1925 
1926 unregister_fs:
1927 	unregister_filesystem(&zonefs_type);
1928 destroy_inodecache:
1929 	zonefs_destroy_inodecache();
1930 
1931 	return ret;
1932 }
1933 
1934 static void __exit zonefs_exit(void)
1935 {
1936 	zonefs_sysfs_exit();
1937 	zonefs_destroy_inodecache();
1938 	unregister_filesystem(&zonefs_type);
1939 }
1940 
1941 MODULE_AUTHOR("Damien Le Moal");
1942 MODULE_DESCRIPTION("Zone file system for zoned block devices");
1943 MODULE_LICENSE("GPL");
1944 MODULE_ALIAS_FS("zonefs");
1945 module_init(zonefs_init);
1946 module_exit(zonefs_exit);
1947