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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/fs.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
27static int zonefs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
28 unsigned int flags, struct iomap *iomap,
29 struct iomap *srcmap)
30{
31 struct zonefs_inode_info *zi = ZONEFS_I(inode);
32 struct super_block *sb = inode->i_sb;
33 loff_t isize;
34
35 /* All I/Os should always be within the file maximum size */
36 if (WARN_ON_ONCE(offset + length > zi->i_max_size))
37 return -EIO;
38
39 /*
40 * Sequential zones can only accept direct writes. This is already
41 * checked when writes are issued, so warn if we see a page writeback
42 * operation.
43 */
44 if (WARN_ON_ONCE(zi->i_ztype == ZONEFS_ZTYPE_SEQ &&
45 (flags & IOMAP_WRITE) && !(flags & IOMAP_DIRECT)))
46 return -EIO;
47
48 /*
49 * For conventional zones, all blocks are always mapped. For sequential
50 * zones, all blocks after always mapped below the inode size (zone
51 * write pointer) and unwriten beyond.
52 */
53 mutex_lock(&zi->i_truncate_mutex);
54 isize = i_size_read(inode);
55 if (offset >= isize)
56 iomap->type = IOMAP_UNWRITTEN;
57 else
58 iomap->type = IOMAP_MAPPED;
59 if (flags & IOMAP_WRITE)
60 length = zi->i_max_size - offset;
61 else
62 length = min(length, isize - offset);
63 mutex_unlock(&zi->i_truncate_mutex);
64
65 iomap->offset = ALIGN_DOWN(offset, sb->s_blocksize);
66 iomap->length = ALIGN(offset + length, sb->s_blocksize) - iomap->offset;
67 iomap->bdev = inode->i_sb->s_bdev;
68 iomap->addr = (zi->i_zsector << SECTOR_SHIFT) + iomap->offset;
69
70 return 0;
71}
72
73static const struct iomap_ops zonefs_iomap_ops = {
74 .iomap_begin = zonefs_iomap_begin,
75};
76
77static int zonefs_readpage(struct file *unused, struct page *page)
78{
79 return iomap_readpage(page, &zonefs_iomap_ops);
80}
81
82static void zonefs_readahead(struct readahead_control *rac)
83{
84 iomap_readahead(rac, &zonefs_iomap_ops);
85}
86
87/*
88 * Map blocks for page writeback. This is used only on conventional zone files,
89 * which implies that the page range can only be within the fixed inode size.
90 */
91static int zonefs_map_blocks(struct iomap_writepage_ctx *wpc,
92 struct inode *inode, loff_t offset)
93{
94 struct zonefs_inode_info *zi = ZONEFS_I(inode);
95
96 if (WARN_ON_ONCE(zi->i_ztype != ZONEFS_ZTYPE_CNV))
97 return -EIO;
98 if (WARN_ON_ONCE(offset >= i_size_read(inode)))
99 return -EIO;
100
101 /* If the mapping is already OK, nothing needs to be done */
102 if (offset >= wpc->iomap.offset &&
103 offset < wpc->iomap.offset + wpc->iomap.length)
104 return 0;
105
106 return zonefs_iomap_begin(inode, offset, zi->i_max_size - offset,
107 IOMAP_WRITE, &wpc->iomap, NULL);
108}
109
110static const struct iomap_writeback_ops zonefs_writeback_ops = {
111 .map_blocks = zonefs_map_blocks,
112};
113
114static int zonefs_writepage(struct page *page, struct writeback_control *wbc)
115{
116 struct iomap_writepage_ctx wpc = { };
117
118 return iomap_writepage(page, wbc, &wpc, &zonefs_writeback_ops);
119}
120
121static int zonefs_writepages(struct address_space *mapping,
122 struct writeback_control *wbc)
123{
124 struct iomap_writepage_ctx wpc = { };
125
126 return iomap_writepages(mapping, wbc, &wpc, &zonefs_writeback_ops);
127}
128
129static const struct address_space_operations zonefs_file_aops = {
130 .readpage = zonefs_readpage,
131 .readahead = zonefs_readahead,
132 .writepage = zonefs_writepage,
133 .writepages = zonefs_writepages,
134 .set_page_dirty = iomap_set_page_dirty,
135 .releasepage = iomap_releasepage,
136 .invalidatepage = iomap_invalidatepage,
137 .migratepage = iomap_migrate_page,
138 .is_partially_uptodate = iomap_is_partially_uptodate,
139 .error_remove_page = generic_error_remove_page,
140 .direct_IO = noop_direct_IO,
141};
142
143static void zonefs_update_stats(struct inode *inode, loff_t new_isize)
144{
145 struct super_block *sb = inode->i_sb;
146 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
147 loff_t old_isize = i_size_read(inode);
148 loff_t nr_blocks;
149
150 if (new_isize == old_isize)
151 return;
152
153 spin_lock(&sbi->s_lock);
154
155 /*
156 * This may be called for an update after an IO error.
157 * So beware of the values seen.
158 */
159 if (new_isize < old_isize) {
160 nr_blocks = (old_isize - new_isize) >> sb->s_blocksize_bits;
161 if (sbi->s_used_blocks > nr_blocks)
162 sbi->s_used_blocks -= nr_blocks;
163 else
164 sbi->s_used_blocks = 0;
165 } else {
166 sbi->s_used_blocks +=
167 (new_isize - old_isize) >> sb->s_blocksize_bits;
168 if (sbi->s_used_blocks > sbi->s_blocks)
169 sbi->s_used_blocks = sbi->s_blocks;
170 }
171
172 spin_unlock(&sbi->s_lock);
173}
174
175/*
176 * Check a zone condition and adjust its file inode access permissions for
177 * offline and readonly zones. Return the inode size corresponding to the
178 * amount of readable data in the zone.
179 */
180static loff_t zonefs_check_zone_condition(struct inode *inode,
181 struct blk_zone *zone, bool warn,
182 bool mount)
183{
184 struct zonefs_inode_info *zi = ZONEFS_I(inode);
185
186 switch (zone->cond) {
187 case BLK_ZONE_COND_OFFLINE:
188 /*
189 * Dead zone: make the inode immutable, disable all accesses
190 * and set the file size to 0 (zone wp set to zone start).
191 */
192 if (warn)
193 zonefs_warn(inode->i_sb, "inode %lu: offline zone\n",
194 inode->i_ino);
195 inode->i_flags |= S_IMMUTABLE;
196 inode->i_mode &= ~0777;
197 zone->wp = zone->start;
198 return 0;
199 case BLK_ZONE_COND_READONLY:
200 /*
201 * The write pointer of read-only zones is invalid. If such a
202 * zone is found during mount, the file size cannot be retrieved
203 * so we treat the zone as offline (mount == true case).
204 * Otherwise, keep the file size as it was when last updated
205 * so that the user can recover data. In both cases, writes are
206 * always disabled for the zone.
207 */
208 if (warn)
209 zonefs_warn(inode->i_sb, "inode %lu: read-only zone\n",
210 inode->i_ino);
211 inode->i_flags |= S_IMMUTABLE;
212 if (mount) {
213 zone->cond = BLK_ZONE_COND_OFFLINE;
214 inode->i_mode &= ~0777;
215 zone->wp = zone->start;
216 return 0;
217 }
218 inode->i_mode &= ~0222;
219 return i_size_read(inode);
220 default:
221 if (zi->i_ztype == ZONEFS_ZTYPE_CNV)
222 return zi->i_max_size;
223 return (zone->wp - zone->start) << SECTOR_SHIFT;
224 }
225}
226
227struct zonefs_ioerr_data {
228 struct inode *inode;
229 bool write;
230};
231
232static int zonefs_io_error_cb(struct blk_zone *zone, unsigned int idx,
233 void *data)
234{
235 struct zonefs_ioerr_data *err = data;
236 struct inode *inode = err->inode;
237 struct zonefs_inode_info *zi = ZONEFS_I(inode);
238 struct super_block *sb = inode->i_sb;
239 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
240 loff_t isize, data_size;
241
242 /*
243 * Check the zone condition: if the zone is not "bad" (offline or
244 * read-only), read errors are simply signaled to the IO issuer as long
245 * as there is no inconsistency between the inode size and the amount of
246 * data writen in the zone (data_size).
247 */
248 data_size = zonefs_check_zone_condition(inode, zone, true, false);
249 isize = i_size_read(inode);
250 if (zone->cond != BLK_ZONE_COND_OFFLINE &&
251 zone->cond != BLK_ZONE_COND_READONLY &&
252 !err->write && isize == data_size)
253 return 0;
254
255 /*
256 * At this point, we detected either a bad zone or an inconsistency
257 * between the inode size and the amount of data written in the zone.
258 * For the latter case, the cause may be a write IO error or an external
259 * action on the device. Two error patterns exist:
260 * 1) The inode size is lower than the amount of data in the zone:
261 * a write operation partially failed and data was writen at the end
262 * of the file. This can happen in the case of a large direct IO
263 * needing several BIOs and/or write requests to be processed.
264 * 2) The inode size is larger than the amount of data in the zone:
265 * this can happen with a deferred write error with the use of the
266 * device side write cache after getting successful write IO
267 * completions. Other possibilities are (a) an external corruption,
268 * e.g. an application reset the zone directly, or (b) the device
269 * has a serious problem (e.g. firmware bug).
270 *
271 * In all cases, warn about inode size inconsistency and handle the
272 * IO error according to the zone condition and to the mount options.
273 */
274 if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && isize != data_size)
275 zonefs_warn(sb, "inode %lu: invalid size %lld (should be %lld)\n",
276 inode->i_ino, isize, data_size);
277
278 /*
279 * First handle bad zones signaled by hardware. The mount options
280 * errors=zone-ro and errors=zone-offline result in changing the
281 * zone condition to read-only and offline respectively, as if the
282 * condition was signaled by the hardware.
283 */
284 if (zone->cond == BLK_ZONE_COND_OFFLINE ||
285 sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL) {
286 zonefs_warn(sb, "inode %lu: read/write access disabled\n",
287 inode->i_ino);
288 if (zone->cond != BLK_ZONE_COND_OFFLINE) {
289 zone->cond = BLK_ZONE_COND_OFFLINE;
290 data_size = zonefs_check_zone_condition(inode, zone,
291 false, false);
292 }
293 } else if (zone->cond == BLK_ZONE_COND_READONLY ||
294 sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO) {
295 zonefs_warn(sb, "inode %lu: write access disabled\n",
296 inode->i_ino);
297 if (zone->cond != BLK_ZONE_COND_READONLY) {
298 zone->cond = BLK_ZONE_COND_READONLY;
299 data_size = zonefs_check_zone_condition(inode, zone,
300 false, false);
301 }
302 }
303
304 /*
305 * If error=remount-ro was specified, any error result in remounting
306 * the volume as read-only.
307 */
308 if ((sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO) && !sb_rdonly(sb)) {
309 zonefs_warn(sb, "remounting filesystem read-only\n");
310 sb->s_flags |= SB_RDONLY;
311 }
312
313 /*
314 * Update block usage stats and the inode size to prevent access to
315 * invalid data.
316 */
317 zonefs_update_stats(inode, data_size);
318 i_size_write(inode, data_size);
319 zi->i_wpoffset = data_size;
320
321 return 0;
322}
323
324/*
325 * When an file IO error occurs, check the file zone to see if there is a change
326 * in the zone condition (e.g. offline or read-only). For a failed write to a
327 * sequential zone, the zone write pointer position must also be checked to
328 * eventually correct the file size and zonefs inode write pointer offset
329 * (which can be out of sync with the drive due to partial write failures).
330 */
331static void zonefs_io_error(struct inode *inode, bool write)
332{
333 struct zonefs_inode_info *zi = ZONEFS_I(inode);
334 struct super_block *sb = inode->i_sb;
335 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
336 unsigned int noio_flag;
337 unsigned int nr_zones =
338 zi->i_zone_size >> (sbi->s_zone_sectors_shift + SECTOR_SHIFT);
339 struct zonefs_ioerr_data err = {
340 .inode = inode,
341 .write = write,
342 };
343 int ret;
344
345 mutex_lock(&zi->i_truncate_mutex);
346
347 /*
348 * Memory allocations in blkdev_report_zones() can trigger a memory
349 * reclaim which may in turn cause a recursion into zonefs as well as
350 * struct request allocations for the same device. The former case may
351 * end up in a deadlock on the inode truncate mutex, while the latter
352 * may prevent IO forward progress. Executing the report zones under
353 * the GFP_NOIO context avoids both problems.
354 */
355 noio_flag = memalloc_noio_save();
356 ret = blkdev_report_zones(sb->s_bdev, zi->i_zsector, nr_zones,
357 zonefs_io_error_cb, &err);
358 if (ret != nr_zones)
359 zonefs_err(sb, "Get inode %lu zone information failed %d\n",
360 inode->i_ino, ret);
361 memalloc_noio_restore(noio_flag);
362
363 mutex_unlock(&zi->i_truncate_mutex);
364}
365
366static int zonefs_file_truncate(struct inode *inode, loff_t isize)
367{
368 struct zonefs_inode_info *zi = ZONEFS_I(inode);
369 loff_t old_isize;
370 enum req_opf op;
371 int ret = 0;
372
373 /*
374 * Only sequential zone files can be truncated and truncation is allowed
375 * only down to a 0 size, which is equivalent to a zone reset, and to
376 * the maximum file size, which is equivalent to a zone finish.
377 */
378 if (zi->i_ztype != ZONEFS_ZTYPE_SEQ)
379 return -EPERM;
380
381 if (!isize)
382 op = REQ_OP_ZONE_RESET;
383 else if (isize == zi->i_max_size)
384 op = REQ_OP_ZONE_FINISH;
385 else
386 return -EPERM;
387
388 inode_dio_wait(inode);
389
390 /* Serialize against page faults */
391 down_write(&zi->i_mmap_sem);
392
393 /* Serialize against zonefs_iomap_begin() */
394 mutex_lock(&zi->i_truncate_mutex);
395
396 old_isize = i_size_read(inode);
397 if (isize == old_isize)
398 goto unlock;
399
400 ret = blkdev_zone_mgmt(inode->i_sb->s_bdev, op, zi->i_zsector,
401 zi->i_zone_size >> SECTOR_SHIFT, GFP_NOFS);
402 if (ret) {
403 zonefs_err(inode->i_sb,
404 "Zone management operation at %llu failed %d",
405 zi->i_zsector, ret);
406 goto unlock;
407 }
408
409 zonefs_update_stats(inode, isize);
410 truncate_setsize(inode, isize);
411 zi->i_wpoffset = isize;
412
413unlock:
414 mutex_unlock(&zi->i_truncate_mutex);
415 up_write(&zi->i_mmap_sem);
416
417 return ret;
418}
419
420static int zonefs_inode_setattr(struct dentry *dentry, struct iattr *iattr)
421{
422 struct inode *inode = d_inode(dentry);
423 int ret;
424
425 if (unlikely(IS_IMMUTABLE(inode)))
426 return -EPERM;
427
428 ret = setattr_prepare(dentry, iattr);
429 if (ret)
430 return ret;
431
432 /*
433 * Since files and directories cannot be created nor deleted, do not
434 * allow setting any write attributes on the sub-directories grouping
435 * files by zone type.
436 */
437 if ((iattr->ia_valid & ATTR_MODE) && S_ISDIR(inode->i_mode) &&
438 (iattr->ia_mode & 0222))
439 return -EPERM;
440
441 if (((iattr->ia_valid & ATTR_UID) &&
442 !uid_eq(iattr->ia_uid, inode->i_uid)) ||
443 ((iattr->ia_valid & ATTR_GID) &&
444 !gid_eq(iattr->ia_gid, inode->i_gid))) {
445 ret = dquot_transfer(inode, iattr);
446 if (ret)
447 return ret;
448 }
449
450 if (iattr->ia_valid & ATTR_SIZE) {
451 ret = zonefs_file_truncate(inode, iattr->ia_size);
452 if (ret)
453 return ret;
454 }
455
456 setattr_copy(inode, iattr);
457
458 return 0;
459}
460
461static const struct inode_operations zonefs_file_inode_operations = {
462 .setattr = zonefs_inode_setattr,
463};
464
465static int zonefs_file_fsync(struct file *file, loff_t start, loff_t end,
466 int datasync)
467{
468 struct inode *inode = file_inode(file);
469 int ret = 0;
470
471 if (unlikely(IS_IMMUTABLE(inode)))
472 return -EPERM;
473
474 /*
475 * Since only direct writes are allowed in sequential files, page cache
476 * flush is needed only for conventional zone files.
477 */
478 if (ZONEFS_I(inode)->i_ztype == ZONEFS_ZTYPE_CNV)
479 ret = file_write_and_wait_range(file, start, end);
480 if (!ret)
481 ret = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL);
482
483 if (ret)
484 zonefs_io_error(inode, true);
485
486 return ret;
487}
488
489static vm_fault_t zonefs_filemap_fault(struct vm_fault *vmf)
490{
491 struct zonefs_inode_info *zi = ZONEFS_I(file_inode(vmf->vma->vm_file));
492 vm_fault_t ret;
493
494 down_read(&zi->i_mmap_sem);
495 ret = filemap_fault(vmf);
496 up_read(&zi->i_mmap_sem);
497
498 return ret;
499}
500
501static vm_fault_t zonefs_filemap_page_mkwrite(struct vm_fault *vmf)
502{
503 struct inode *inode = file_inode(vmf->vma->vm_file);
504 struct zonefs_inode_info *zi = ZONEFS_I(inode);
505 vm_fault_t ret;
506
507 if (unlikely(IS_IMMUTABLE(inode)))
508 return VM_FAULT_SIGBUS;
509
510 /*
511 * Sanity check: only conventional zone files can have shared
512 * writeable mappings.
513 */
514 if (WARN_ON_ONCE(zi->i_ztype != ZONEFS_ZTYPE_CNV))
515 return VM_FAULT_NOPAGE;
516
517 sb_start_pagefault(inode->i_sb);
518 file_update_time(vmf->vma->vm_file);
519
520 /* Serialize against truncates */
521 down_read(&zi->i_mmap_sem);
522 ret = iomap_page_mkwrite(vmf, &zonefs_iomap_ops);
523 up_read(&zi->i_mmap_sem);
524
525 sb_end_pagefault(inode->i_sb);
526 return ret;
527}
528
529static const struct vm_operations_struct zonefs_file_vm_ops = {
530 .fault = zonefs_filemap_fault,
531 .map_pages = filemap_map_pages,
532 .page_mkwrite = zonefs_filemap_page_mkwrite,
533};
534
535static int zonefs_file_mmap(struct file *file, struct vm_area_struct *vma)
536{
537 /*
538 * Conventional zones accept random writes, so their files can support
539 * shared writable mappings. For sequential zone files, only read
540 * mappings are possible since there are no guarantees for write
541 * ordering between msync() and page cache writeback.
542 */
543 if (ZONEFS_I(file_inode(file))->i_ztype == ZONEFS_ZTYPE_SEQ &&
544 (vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
545 return -EINVAL;
546
547 file_accessed(file);
548 vma->vm_ops = &zonefs_file_vm_ops;
549
550 return 0;
551}
552
553static loff_t zonefs_file_llseek(struct file *file, loff_t offset, int whence)
554{
555 loff_t isize = i_size_read(file_inode(file));
556
557 /*
558 * Seeks are limited to below the zone size for conventional zones
559 * and below the zone write pointer for sequential zones. In both
560 * cases, this limit is the inode size.
561 */
562 return generic_file_llseek_size(file, offset, whence, isize, isize);
563}
564
565static int zonefs_file_write_dio_end_io(struct kiocb *iocb, ssize_t size,
566 int error, unsigned int flags)
567{
568 struct inode *inode = file_inode(iocb->ki_filp);
569 struct zonefs_inode_info *zi = ZONEFS_I(inode);
570
571 if (error) {
572 zonefs_io_error(inode, true);
573 return error;
574 }
575
576 if (size && zi->i_ztype != ZONEFS_ZTYPE_CNV) {
577 /*
578 * Note that we may be seeing completions out of order,
579 * but that is not a problem since a write completed
580 * successfully necessarily means that all preceding writes
581 * were also successful. So we can safely increase the inode
582 * size to the write end location.
583 */
584 mutex_lock(&zi->i_truncate_mutex);
585 if (i_size_read(inode) < iocb->ki_pos + size) {
586 zonefs_update_stats(inode, iocb->ki_pos + size);
587 i_size_write(inode, iocb->ki_pos + size);
588 }
589 mutex_unlock(&zi->i_truncate_mutex);
590 }
591
592 return 0;
593}
594
595static const struct iomap_dio_ops zonefs_write_dio_ops = {
596 .end_io = zonefs_file_write_dio_end_io,
597};
598
599static ssize_t zonefs_file_dio_append(struct kiocb *iocb, struct iov_iter *from)
600{
601 struct inode *inode = file_inode(iocb->ki_filp);
602 struct zonefs_inode_info *zi = ZONEFS_I(inode);
603 struct block_device *bdev = inode->i_sb->s_bdev;
604 unsigned int max;
605 struct bio *bio;
606 ssize_t size;
607 int nr_pages;
608 ssize_t ret;
609
610 max = queue_max_zone_append_sectors(bdev_get_queue(bdev));
611 max = ALIGN_DOWN(max << SECTOR_SHIFT, inode->i_sb->s_blocksize);
612 iov_iter_truncate(from, max);
613
614 nr_pages = iov_iter_npages(from, BIO_MAX_PAGES);
615 if (!nr_pages)
616 return 0;
617
618 bio = bio_alloc_bioset(GFP_NOFS, nr_pages, &fs_bio_set);
619 if (!bio)
620 return -ENOMEM;
621
622 bio_set_dev(bio, bdev);
623 bio->bi_iter.bi_sector = zi->i_zsector;
624 bio->bi_write_hint = iocb->ki_hint;
625 bio->bi_ioprio = iocb->ki_ioprio;
626 bio->bi_opf = REQ_OP_ZONE_APPEND | REQ_SYNC | REQ_IDLE;
627 if (iocb->ki_flags & IOCB_DSYNC)
628 bio->bi_opf |= REQ_FUA;
629
630 ret = bio_iov_iter_get_pages(bio, from);
631 if (unlikely(ret)) {
632 bio_io_error(bio);
633 return ret;
634 }
635 size = bio->bi_iter.bi_size;
636 task_io_account_write(ret);
637
638 if (iocb->ki_flags & IOCB_HIPRI)
639 bio_set_polled(bio, iocb);
640
641 ret = submit_bio_wait(bio);
642
643 bio_put(bio);
644
645 zonefs_file_write_dio_end_io(iocb, size, ret, 0);
646 if (ret >= 0) {
647 iocb->ki_pos += size;
648 return size;
649 }
650
651 return ret;
652}
653
654/*
655 * Handle direct writes. For sequential zone files, this is the only possible
656 * write path. For these files, check that the user is issuing writes
657 * sequentially from the end of the file. This code assumes that the block layer
658 * delivers write requests to the device in sequential order. This is always the
659 * case if a block IO scheduler implementing the ELEVATOR_F_ZBD_SEQ_WRITE
660 * elevator feature is being used (e.g. mq-deadline). The block layer always
661 * automatically select such an elevator for zoned block devices during the
662 * device initialization.
663 */
664static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
665{
666 struct inode *inode = file_inode(iocb->ki_filp);
667 struct zonefs_inode_info *zi = ZONEFS_I(inode);
668 struct super_block *sb = inode->i_sb;
669 bool sync = is_sync_kiocb(iocb);
670 bool append = false;
671 size_t count;
672 ssize_t ret;
673
674 /*
675 * For async direct IOs to sequential zone files, refuse IOCB_NOWAIT
676 * as this can cause write reordering (e.g. the first aio gets EAGAIN
677 * on the inode lock but the second goes through but is now unaligned).
678 */
679 if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && !sync &&
680 (iocb->ki_flags & IOCB_NOWAIT))
681 return -EOPNOTSUPP;
682
683 if (iocb->ki_flags & IOCB_NOWAIT) {
684 if (!inode_trylock(inode))
685 return -EAGAIN;
686 } else {
687 inode_lock(inode);
688 }
689
690 ret = generic_write_checks(iocb, from);
691 if (ret <= 0)
692 goto inode_unlock;
693
694 iov_iter_truncate(from, zi->i_max_size - iocb->ki_pos);
695 count = iov_iter_count(from);
696
697 if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
698 ret = -EINVAL;
699 goto inode_unlock;
700 }
701
702 /* Enforce sequential writes (append only) in sequential zones */
703 if (zi->i_ztype == ZONEFS_ZTYPE_SEQ) {
704 mutex_lock(&zi->i_truncate_mutex);
705 if (iocb->ki_pos != zi->i_wpoffset) {
706 mutex_unlock(&zi->i_truncate_mutex);
707 ret = -EINVAL;
708 goto inode_unlock;
709 }
710 mutex_unlock(&zi->i_truncate_mutex);
711 append = sync;
712 }
713
714 if (append)
715 ret = zonefs_file_dio_append(iocb, from);
716 else
717 ret = iomap_dio_rw(iocb, from, &zonefs_iomap_ops,
718 &zonefs_write_dio_ops, sync);
719 if (zi->i_ztype == ZONEFS_ZTYPE_SEQ &&
720 (ret > 0 || ret == -EIOCBQUEUED)) {
721 if (ret > 0)
722 count = ret;
723 mutex_lock(&zi->i_truncate_mutex);
724 zi->i_wpoffset += count;
725 mutex_unlock(&zi->i_truncate_mutex);
726 }
727
728inode_unlock:
729 inode_unlock(inode);
730
731 return ret;
732}
733
734static ssize_t zonefs_file_buffered_write(struct kiocb *iocb,
735 struct iov_iter *from)
736{
737 struct inode *inode = file_inode(iocb->ki_filp);
738 struct zonefs_inode_info *zi = ZONEFS_I(inode);
739 ssize_t ret;
740
741 /*
742 * Direct IO writes are mandatory for sequential zone files so that the
743 * write IO issuing order is preserved.
744 */
745 if (zi->i_ztype != ZONEFS_ZTYPE_CNV)
746 return -EIO;
747
748 if (iocb->ki_flags & IOCB_NOWAIT) {
749 if (!inode_trylock(inode))
750 return -EAGAIN;
751 } else {
752 inode_lock(inode);
753 }
754
755 ret = generic_write_checks(iocb, from);
756 if (ret <= 0)
757 goto inode_unlock;
758
759 iov_iter_truncate(from, zi->i_max_size - iocb->ki_pos);
760
761 ret = iomap_file_buffered_write(iocb, from, &zonefs_iomap_ops);
762 if (ret > 0)
763 iocb->ki_pos += ret;
764 else if (ret == -EIO)
765 zonefs_io_error(inode, true);
766
767inode_unlock:
768 inode_unlock(inode);
769 if (ret > 0)
770 ret = generic_write_sync(iocb, ret);
771
772 return ret;
773}
774
775static ssize_t zonefs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
776{
777 struct inode *inode = file_inode(iocb->ki_filp);
778
779 if (unlikely(IS_IMMUTABLE(inode)))
780 return -EPERM;
781
782 if (sb_rdonly(inode->i_sb))
783 return -EROFS;
784
785 /* Write operations beyond the zone size are not allowed */
786 if (iocb->ki_pos >= ZONEFS_I(inode)->i_max_size)
787 return -EFBIG;
788
789 if (iocb->ki_flags & IOCB_DIRECT) {
790 ssize_t ret = zonefs_file_dio_write(iocb, from);
791 if (ret != -ENOTBLK)
792 return ret;
793 }
794
795 return zonefs_file_buffered_write(iocb, from);
796}
797
798static int zonefs_file_read_dio_end_io(struct kiocb *iocb, ssize_t size,
799 int error, unsigned int flags)
800{
801 if (error) {
802 zonefs_io_error(file_inode(iocb->ki_filp), false);
803 return error;
804 }
805
806 return 0;
807}
808
809static const struct iomap_dio_ops zonefs_read_dio_ops = {
810 .end_io = zonefs_file_read_dio_end_io,
811};
812
813static ssize_t zonefs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
814{
815 struct inode *inode = file_inode(iocb->ki_filp);
816 struct zonefs_inode_info *zi = ZONEFS_I(inode);
817 struct super_block *sb = inode->i_sb;
818 loff_t isize;
819 ssize_t ret;
820
821 /* Offline zones cannot be read */
822 if (unlikely(IS_IMMUTABLE(inode) && !(inode->i_mode & 0777)))
823 return -EPERM;
824
825 if (iocb->ki_pos >= zi->i_max_size)
826 return 0;
827
828 if (iocb->ki_flags & IOCB_NOWAIT) {
829 if (!inode_trylock_shared(inode))
830 return -EAGAIN;
831 } else {
832 inode_lock_shared(inode);
833 }
834
835 /* Limit read operations to written data */
836 mutex_lock(&zi->i_truncate_mutex);
837 isize = i_size_read(inode);
838 if (iocb->ki_pos >= isize) {
839 mutex_unlock(&zi->i_truncate_mutex);
840 ret = 0;
841 goto inode_unlock;
842 }
843 iov_iter_truncate(to, isize - iocb->ki_pos);
844 mutex_unlock(&zi->i_truncate_mutex);
845
846 if (iocb->ki_flags & IOCB_DIRECT) {
847 size_t count = iov_iter_count(to);
848
849 if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) {
850 ret = -EINVAL;
851 goto inode_unlock;
852 }
853 file_accessed(iocb->ki_filp);
854 ret = iomap_dio_rw(iocb, to, &zonefs_iomap_ops,
855 &zonefs_read_dio_ops, is_sync_kiocb(iocb));
856 } else {
857 ret = generic_file_read_iter(iocb, to);
858 if (ret == -EIO)
859 zonefs_io_error(inode, false);
860 }
861
862inode_unlock:
863 inode_unlock_shared(inode);
864
865 return ret;
866}
867
868static const struct file_operations zonefs_file_operations = {
869 .open = generic_file_open,
870 .fsync = zonefs_file_fsync,
871 .mmap = zonefs_file_mmap,
872 .llseek = zonefs_file_llseek,
873 .read_iter = zonefs_file_read_iter,
874 .write_iter = zonefs_file_write_iter,
875 .splice_read = generic_file_splice_read,
876 .splice_write = iter_file_splice_write,
877 .iopoll = iomap_dio_iopoll,
878};
879
880static struct kmem_cache *zonefs_inode_cachep;
881
882static struct inode *zonefs_alloc_inode(struct super_block *sb)
883{
884 struct zonefs_inode_info *zi;
885
886 zi = kmem_cache_alloc(zonefs_inode_cachep, GFP_KERNEL);
887 if (!zi)
888 return NULL;
889
890 inode_init_once(&zi->i_vnode);
891 mutex_init(&zi->i_truncate_mutex);
892 init_rwsem(&zi->i_mmap_sem);
893
894 return &zi->i_vnode;
895}
896
897static void zonefs_free_inode(struct inode *inode)
898{
899 kmem_cache_free(zonefs_inode_cachep, ZONEFS_I(inode));
900}
901
902/*
903 * File system stat.
904 */
905static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf)
906{
907 struct super_block *sb = dentry->d_sb;
908 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
909 enum zonefs_ztype t;
910 u64 fsid;
911
912 buf->f_type = ZONEFS_MAGIC;
913 buf->f_bsize = sb->s_blocksize;
914 buf->f_namelen = ZONEFS_NAME_MAX;
915
916 spin_lock(&sbi->s_lock);
917
918 buf->f_blocks = sbi->s_blocks;
919 if (WARN_ON(sbi->s_used_blocks > sbi->s_blocks))
920 buf->f_bfree = 0;
921 else
922 buf->f_bfree = buf->f_blocks - sbi->s_used_blocks;
923 buf->f_bavail = buf->f_bfree;
924
925 for (t = 0; t < ZONEFS_ZTYPE_MAX; t++) {
926 if (sbi->s_nr_files[t])
927 buf->f_files += sbi->s_nr_files[t] + 1;
928 }
929 buf->f_ffree = 0;
930
931 spin_unlock(&sbi->s_lock);
932
933 fsid = le64_to_cpup((void *)sbi->s_uuid.b) ^
934 le64_to_cpup((void *)sbi->s_uuid.b + sizeof(u64));
935 buf->f_fsid.val[0] = (u32)fsid;
936 buf->f_fsid.val[1] = (u32)(fsid >> 32);
937
938 return 0;
939}
940
941enum {
942 Opt_errors_ro, Opt_errors_zro, Opt_errors_zol, Opt_errors_repair,
943 Opt_err,
944};
945
946static const match_table_t tokens = {
947 { Opt_errors_ro, "errors=remount-ro"},
948 { Opt_errors_zro, "errors=zone-ro"},
949 { Opt_errors_zol, "errors=zone-offline"},
950 { Opt_errors_repair, "errors=repair"},
951 { Opt_err, NULL}
952};
953
954static int zonefs_parse_options(struct super_block *sb, char *options)
955{
956 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
957 substring_t args[MAX_OPT_ARGS];
958 char *p;
959
960 if (!options)
961 return 0;
962
963 while ((p = strsep(&options, ",")) != NULL) {
964 int token;
965
966 if (!*p)
967 continue;
968
969 token = match_token(p, tokens, args);
970 switch (token) {
971 case Opt_errors_ro:
972 sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
973 sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_RO;
974 break;
975 case Opt_errors_zro:
976 sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
977 sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_ZRO;
978 break;
979 case Opt_errors_zol:
980 sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
981 sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_ZOL;
982 break;
983 case Opt_errors_repair:
984 sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
985 sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_REPAIR;
986 break;
987 default:
988 return -EINVAL;
989 }
990 }
991
992 return 0;
993}
994
995static int zonefs_show_options(struct seq_file *seq, struct dentry *root)
996{
997 struct zonefs_sb_info *sbi = ZONEFS_SB(root->d_sb);
998
999 if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO)
1000 seq_puts(seq, ",errors=remount-ro");
1001 if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO)
1002 seq_puts(seq, ",errors=zone-ro");
1003 if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL)
1004 seq_puts(seq, ",errors=zone-offline");
1005 if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_REPAIR)
1006 seq_puts(seq, ",errors=repair");
1007
1008 return 0;
1009}
1010
1011static int zonefs_remount(struct super_block *sb, int *flags, char *data)
1012{
1013 sync_filesystem(sb);
1014
1015 return zonefs_parse_options(sb, data);
1016}
1017
1018static const struct super_operations zonefs_sops = {
1019 .alloc_inode = zonefs_alloc_inode,
1020 .free_inode = zonefs_free_inode,
1021 .statfs = zonefs_statfs,
1022 .remount_fs = zonefs_remount,
1023 .show_options = zonefs_show_options,
1024};
1025
1026static const struct inode_operations zonefs_dir_inode_operations = {
1027 .lookup = simple_lookup,
1028 .setattr = zonefs_inode_setattr,
1029};
1030
1031static void zonefs_init_dir_inode(struct inode *parent, struct inode *inode,
1032 enum zonefs_ztype type)
1033{
1034 struct super_block *sb = parent->i_sb;
1035
1036 inode->i_ino = blkdev_nr_zones(sb->s_bdev->bd_disk) + type + 1;
1037 inode_init_owner(inode, parent, S_IFDIR | 0555);
1038 inode->i_op = &zonefs_dir_inode_operations;
1039 inode->i_fop = &simple_dir_operations;
1040 set_nlink(inode, 2);
1041 inc_nlink(parent);
1042}
1043
1044static void zonefs_init_file_inode(struct inode *inode, struct blk_zone *zone,
1045 enum zonefs_ztype type)
1046{
1047 struct super_block *sb = inode->i_sb;
1048 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1049 struct zonefs_inode_info *zi = ZONEFS_I(inode);
1050
1051 inode->i_ino = zone->start >> sbi->s_zone_sectors_shift;
1052 inode->i_mode = S_IFREG | sbi->s_perm;
1053
1054 zi->i_ztype = type;
1055 zi->i_zsector = zone->start;
1056 zi->i_zone_size = zone->len << SECTOR_SHIFT;
1057
1058 zi->i_max_size = min_t(loff_t, MAX_LFS_FILESIZE,
1059 zone->capacity << SECTOR_SHIFT);
1060 zi->i_wpoffset = zonefs_check_zone_condition(inode, zone, true, true);
1061
1062 inode->i_uid = sbi->s_uid;
1063 inode->i_gid = sbi->s_gid;
1064 inode->i_size = zi->i_wpoffset;
1065 inode->i_blocks = zi->i_max_size >> SECTOR_SHIFT;
1066
1067 inode->i_op = &zonefs_file_inode_operations;
1068 inode->i_fop = &zonefs_file_operations;
1069 inode->i_mapping->a_ops = &zonefs_file_aops;
1070
1071 sb->s_maxbytes = max(zi->i_max_size, sb->s_maxbytes);
1072 sbi->s_blocks += zi->i_max_size >> sb->s_blocksize_bits;
1073 sbi->s_used_blocks += zi->i_wpoffset >> sb->s_blocksize_bits;
1074}
1075
1076static struct dentry *zonefs_create_inode(struct dentry *parent,
1077 const char *name, struct blk_zone *zone,
1078 enum zonefs_ztype type)
1079{
1080 struct inode *dir = d_inode(parent);
1081 struct dentry *dentry;
1082 struct inode *inode;
1083
1084 dentry = d_alloc_name(parent, name);
1085 if (!dentry)
1086 return NULL;
1087
1088 inode = new_inode(parent->d_sb);
1089 if (!inode)
1090 goto dput;
1091
1092 inode->i_ctime = inode->i_mtime = inode->i_atime = dir->i_ctime;
1093 if (zone)
1094 zonefs_init_file_inode(inode, zone, type);
1095 else
1096 zonefs_init_dir_inode(dir, inode, type);
1097 d_add(dentry, inode);
1098 dir->i_size++;
1099
1100 return dentry;
1101
1102dput:
1103 dput(dentry);
1104
1105 return NULL;
1106}
1107
1108struct zonefs_zone_data {
1109 struct super_block *sb;
1110 unsigned int nr_zones[ZONEFS_ZTYPE_MAX];
1111 struct blk_zone *zones;
1112};
1113
1114/*
1115 * Create a zone group and populate it with zone files.
1116 */
1117static int zonefs_create_zgroup(struct zonefs_zone_data *zd,
1118 enum zonefs_ztype type)
1119{
1120 struct super_block *sb = zd->sb;
1121 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1122 struct blk_zone *zone, *next, *end;
1123 const char *zgroup_name;
1124 char *file_name;
1125 struct dentry *dir;
1126 unsigned int n = 0;
1127 int ret;
1128
1129 /* If the group is empty, there is nothing to do */
1130 if (!zd->nr_zones[type])
1131 return 0;
1132
1133 file_name = kmalloc(ZONEFS_NAME_MAX, GFP_KERNEL);
1134 if (!file_name)
1135 return -ENOMEM;
1136
1137 if (type == ZONEFS_ZTYPE_CNV)
1138 zgroup_name = "cnv";
1139 else
1140 zgroup_name = "seq";
1141
1142 dir = zonefs_create_inode(sb->s_root, zgroup_name, NULL, type);
1143 if (!dir) {
1144 ret = -ENOMEM;
1145 goto free;
1146 }
1147
1148 /*
1149 * The first zone contains the super block: skip it.
1150 */
1151 end = zd->zones + blkdev_nr_zones(sb->s_bdev->bd_disk);
1152 for (zone = &zd->zones[1]; zone < end; zone = next) {
1153
1154 next = zone + 1;
1155 if (zonefs_zone_type(zone) != type)
1156 continue;
1157
1158 /*
1159 * For conventional zones, contiguous zones can be aggregated
1160 * together to form larger files. Note that this overwrites the
1161 * length of the first zone of the set of contiguous zones
1162 * aggregated together. If one offline or read-only zone is
1163 * found, assume that all zones aggregated have the same
1164 * condition.
1165 */
1166 if (type == ZONEFS_ZTYPE_CNV &&
1167 (sbi->s_features & ZONEFS_F_AGGRCNV)) {
1168 for (; next < end; next++) {
1169 if (zonefs_zone_type(next) != type)
1170 break;
1171 zone->len += next->len;
1172 zone->capacity += next->capacity;
1173 if (next->cond == BLK_ZONE_COND_READONLY &&
1174 zone->cond != BLK_ZONE_COND_OFFLINE)
1175 zone->cond = BLK_ZONE_COND_READONLY;
1176 else if (next->cond == BLK_ZONE_COND_OFFLINE)
1177 zone->cond = BLK_ZONE_COND_OFFLINE;
1178 }
1179 if (zone->capacity != zone->len) {
1180 zonefs_err(sb, "Invalid conventional zone capacity\n");
1181 ret = -EINVAL;
1182 goto free;
1183 }
1184 }
1185
1186 /*
1187 * Use the file number within its group as file name.
1188 */
1189 snprintf(file_name, ZONEFS_NAME_MAX - 1, "%u", n);
1190 if (!zonefs_create_inode(dir, file_name, zone, type)) {
1191 ret = -ENOMEM;
1192 goto free;
1193 }
1194
1195 n++;
1196 }
1197
1198 zonefs_info(sb, "Zone group \"%s\" has %u file%s\n",
1199 zgroup_name, n, n > 1 ? "s" : "");
1200
1201 sbi->s_nr_files[type] = n;
1202 ret = 0;
1203
1204free:
1205 kfree(file_name);
1206
1207 return ret;
1208}
1209
1210static int zonefs_get_zone_info_cb(struct blk_zone *zone, unsigned int idx,
1211 void *data)
1212{
1213 struct zonefs_zone_data *zd = data;
1214
1215 /*
1216 * Count the number of usable zones: the first zone at index 0 contains
1217 * the super block and is ignored.
1218 */
1219 switch (zone->type) {
1220 case BLK_ZONE_TYPE_CONVENTIONAL:
1221 zone->wp = zone->start + zone->len;
1222 if (idx)
1223 zd->nr_zones[ZONEFS_ZTYPE_CNV]++;
1224 break;
1225 case BLK_ZONE_TYPE_SEQWRITE_REQ:
1226 case BLK_ZONE_TYPE_SEQWRITE_PREF:
1227 if (idx)
1228 zd->nr_zones[ZONEFS_ZTYPE_SEQ]++;
1229 break;
1230 default:
1231 zonefs_err(zd->sb, "Unsupported zone type 0x%x\n",
1232 zone->type);
1233 return -EIO;
1234 }
1235
1236 memcpy(&zd->zones[idx], zone, sizeof(struct blk_zone));
1237
1238 return 0;
1239}
1240
1241static int zonefs_get_zone_info(struct zonefs_zone_data *zd)
1242{
1243 struct block_device *bdev = zd->sb->s_bdev;
1244 int ret;
1245
1246 zd->zones = kvcalloc(blkdev_nr_zones(bdev->bd_disk),
1247 sizeof(struct blk_zone), GFP_KERNEL);
1248 if (!zd->zones)
1249 return -ENOMEM;
1250
1251 /* Get zones information from the device */
1252 ret = blkdev_report_zones(bdev, 0, BLK_ALL_ZONES,
1253 zonefs_get_zone_info_cb, zd);
1254 if (ret < 0) {
1255 zonefs_err(zd->sb, "Zone report failed %d\n", ret);
1256 return ret;
1257 }
1258
1259 if (ret != blkdev_nr_zones(bdev->bd_disk)) {
1260 zonefs_err(zd->sb, "Invalid zone report (%d/%u zones)\n",
1261 ret, blkdev_nr_zones(bdev->bd_disk));
1262 return -EIO;
1263 }
1264
1265 return 0;
1266}
1267
1268static inline void zonefs_cleanup_zone_info(struct zonefs_zone_data *zd)
1269{
1270 kvfree(zd->zones);
1271}
1272
1273/*
1274 * Read super block information from the device.
1275 */
1276static int zonefs_read_super(struct super_block *sb)
1277{
1278 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1279 struct zonefs_super *super;
1280 u32 crc, stored_crc;
1281 struct page *page;
1282 struct bio_vec bio_vec;
1283 struct bio bio;
1284 int ret;
1285
1286 page = alloc_page(GFP_KERNEL);
1287 if (!page)
1288 return -ENOMEM;
1289
1290 bio_init(&bio, &bio_vec, 1);
1291 bio.bi_iter.bi_sector = 0;
1292 bio.bi_opf = REQ_OP_READ;
1293 bio_set_dev(&bio, sb->s_bdev);
1294 bio_add_page(&bio, page, PAGE_SIZE, 0);
1295
1296 ret = submit_bio_wait(&bio);
1297 if (ret)
1298 goto free_page;
1299
1300 super = kmap(page);
1301
1302 ret = -EINVAL;
1303 if (le32_to_cpu(super->s_magic) != ZONEFS_MAGIC)
1304 goto unmap;
1305
1306 stored_crc = le32_to_cpu(super->s_crc);
1307 super->s_crc = 0;
1308 crc = crc32(~0U, (unsigned char *)super, sizeof(struct zonefs_super));
1309 if (crc != stored_crc) {
1310 zonefs_err(sb, "Invalid checksum (Expected 0x%08x, got 0x%08x)",
1311 crc, stored_crc);
1312 goto unmap;
1313 }
1314
1315 sbi->s_features = le64_to_cpu(super->s_features);
1316 if (sbi->s_features & ~ZONEFS_F_DEFINED_FEATURES) {
1317 zonefs_err(sb, "Unknown features set 0x%llx\n",
1318 sbi->s_features);
1319 goto unmap;
1320 }
1321
1322 if (sbi->s_features & ZONEFS_F_UID) {
1323 sbi->s_uid = make_kuid(current_user_ns(),
1324 le32_to_cpu(super->s_uid));
1325 if (!uid_valid(sbi->s_uid)) {
1326 zonefs_err(sb, "Invalid UID feature\n");
1327 goto unmap;
1328 }
1329 }
1330
1331 if (sbi->s_features & ZONEFS_F_GID) {
1332 sbi->s_gid = make_kgid(current_user_ns(),
1333 le32_to_cpu(super->s_gid));
1334 if (!gid_valid(sbi->s_gid)) {
1335 zonefs_err(sb, "Invalid GID feature\n");
1336 goto unmap;
1337 }
1338 }
1339
1340 if (sbi->s_features & ZONEFS_F_PERM)
1341 sbi->s_perm = le32_to_cpu(super->s_perm);
1342
1343 if (memchr_inv(super->s_reserved, 0, sizeof(super->s_reserved))) {
1344 zonefs_err(sb, "Reserved area is being used\n");
1345 goto unmap;
1346 }
1347
1348 import_uuid(&sbi->s_uuid, super->s_uuid);
1349 ret = 0;
1350
1351unmap:
1352 kunmap(page);
1353free_page:
1354 __free_page(page);
1355
1356 return ret;
1357}
1358
1359/*
1360 * Check that the device is zoned. If it is, get the list of zones and create
1361 * sub-directories and files according to the device zone configuration and
1362 * format options.
1363 */
1364static int zonefs_fill_super(struct super_block *sb, void *data, int silent)
1365{
1366 struct zonefs_zone_data zd;
1367 struct zonefs_sb_info *sbi;
1368 struct inode *inode;
1369 enum zonefs_ztype t;
1370 int ret;
1371
1372 if (!bdev_is_zoned(sb->s_bdev)) {
1373 zonefs_err(sb, "Not a zoned block device\n");
1374 return -EINVAL;
1375 }
1376
1377 /*
1378 * Initialize super block information: the maximum file size is updated
1379 * when the zone files are created so that the format option
1380 * ZONEFS_F_AGGRCNV which increases the maximum file size of a file
1381 * beyond the zone size is taken into account.
1382 */
1383 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1384 if (!sbi)
1385 return -ENOMEM;
1386
1387 spin_lock_init(&sbi->s_lock);
1388 sb->s_fs_info = sbi;
1389 sb->s_magic = ZONEFS_MAGIC;
1390 sb->s_maxbytes = 0;
1391 sb->s_op = &zonefs_sops;
1392 sb->s_time_gran = 1;
1393
1394 /*
1395 * The block size is set to the device physical sector size to ensure
1396 * that write operations on 512e devices (512B logical block and 4KB
1397 * physical block) are always aligned to the device physical blocks,
1398 * as mandated by the ZBC/ZAC specifications.
1399 */
1400 sb_set_blocksize(sb, bdev_physical_block_size(sb->s_bdev));
1401 sbi->s_zone_sectors_shift = ilog2(bdev_zone_sectors(sb->s_bdev));
1402 sbi->s_uid = GLOBAL_ROOT_UID;
1403 sbi->s_gid = GLOBAL_ROOT_GID;
1404 sbi->s_perm = 0640;
1405 sbi->s_mount_opts = ZONEFS_MNTOPT_ERRORS_RO;
1406
1407 ret = zonefs_read_super(sb);
1408 if (ret)
1409 return ret;
1410
1411 ret = zonefs_parse_options(sb, data);
1412 if (ret)
1413 return ret;
1414
1415 memset(&zd, 0, sizeof(struct zonefs_zone_data));
1416 zd.sb = sb;
1417 ret = zonefs_get_zone_info(&zd);
1418 if (ret)
1419 goto cleanup;
1420
1421 zonefs_info(sb, "Mounting %u zones",
1422 blkdev_nr_zones(sb->s_bdev->bd_disk));
1423
1424 /* Create root directory inode */
1425 ret = -ENOMEM;
1426 inode = new_inode(sb);
1427 if (!inode)
1428 goto cleanup;
1429
1430 inode->i_ino = blkdev_nr_zones(sb->s_bdev->bd_disk);
1431 inode->i_mode = S_IFDIR | 0555;
1432 inode->i_ctime = inode->i_mtime = inode->i_atime = current_time(inode);
1433 inode->i_op = &zonefs_dir_inode_operations;
1434 inode->i_fop = &simple_dir_operations;
1435 set_nlink(inode, 2);
1436
1437 sb->s_root = d_make_root(inode);
1438 if (!sb->s_root)
1439 goto cleanup;
1440
1441 /* Create and populate files in zone groups directories */
1442 for (t = 0; t < ZONEFS_ZTYPE_MAX; t++) {
1443 ret = zonefs_create_zgroup(&zd, t);
1444 if (ret)
1445 break;
1446 }
1447
1448cleanup:
1449 zonefs_cleanup_zone_info(&zd);
1450
1451 return ret;
1452}
1453
1454static struct dentry *zonefs_mount(struct file_system_type *fs_type,
1455 int flags, const char *dev_name, void *data)
1456{
1457 return mount_bdev(fs_type, flags, dev_name, data, zonefs_fill_super);
1458}
1459
1460static void zonefs_kill_super(struct super_block *sb)
1461{
1462 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1463
1464 if (sb->s_root)
1465 d_genocide(sb->s_root);
1466 kill_block_super(sb);
1467 kfree(sbi);
1468}
1469
1470/*
1471 * File system definition and registration.
1472 */
1473static struct file_system_type zonefs_type = {
1474 .owner = THIS_MODULE,
1475 .name = "zonefs",
1476 .mount = zonefs_mount,
1477 .kill_sb = zonefs_kill_super,
1478 .fs_flags = FS_REQUIRES_DEV,
1479};
1480
1481static int __init zonefs_init_inodecache(void)
1482{
1483 zonefs_inode_cachep = kmem_cache_create("zonefs_inode_cache",
1484 sizeof(struct zonefs_inode_info), 0,
1485 (SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT),
1486 NULL);
1487 if (zonefs_inode_cachep == NULL)
1488 return -ENOMEM;
1489 return 0;
1490}
1491
1492static void zonefs_destroy_inodecache(void)
1493{
1494 /*
1495 * Make sure all delayed rcu free inodes are flushed before we
1496 * destroy the inode cache.
1497 */
1498 rcu_barrier();
1499 kmem_cache_destroy(zonefs_inode_cachep);
1500}
1501
1502static int __init zonefs_init(void)
1503{
1504 int ret;
1505
1506 BUILD_BUG_ON(sizeof(struct zonefs_super) != ZONEFS_SUPER_SIZE);
1507
1508 ret = zonefs_init_inodecache();
1509 if (ret)
1510 return ret;
1511
1512 ret = register_filesystem(&zonefs_type);
1513 if (ret) {
1514 zonefs_destroy_inodecache();
1515 return ret;
1516 }
1517
1518 return 0;
1519}
1520
1521static void __exit zonefs_exit(void)
1522{
1523 zonefs_destroy_inodecache();
1524 unregister_filesystem(&zonefs_type);
1525}
1526
1527MODULE_AUTHOR("Damien Le Moal");
1528MODULE_DESCRIPTION("Zone file system for zoned block devices");
1529MODULE_LICENSE("GPL");
1530module_init(zonefs_init);
1531module_exit(zonefs_exit);