xref: /openbmc/linux/fs/zonefs/super.c (revision 7583028d)
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   * Get the name of a zone group directory.
32   */
33  static const char *zonefs_zgroup_name(enum zonefs_ztype ztype)
34  {
35  	switch (ztype) {
36  	case ZONEFS_ZTYPE_CNV:
37  		return "cnv";
38  	case ZONEFS_ZTYPE_SEQ:
39  		return "seq";
40  	default:
41  		WARN_ON_ONCE(1);
42  		return "???";
43  	}
44  }
45  
46  /*
47   * Manage the active zone count.
48   */
49  static void zonefs_account_active(struct super_block *sb,
50  				  struct zonefs_zone *z)
51  {
52  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
53  
54  	if (zonefs_zone_is_cnv(z))
55  		return;
56  
57  	/*
58  	 * For zones that transitioned to the offline or readonly condition,
59  	 * we only need to clear the active state.
60  	 */
61  	if (z->z_flags & (ZONEFS_ZONE_OFFLINE | ZONEFS_ZONE_READONLY))
62  		goto out;
63  
64  	/*
65  	 * If the zone is active, that is, if it is explicitly open or
66  	 * partially written, check if it was already accounted as active.
67  	 */
68  	if ((z->z_flags & ZONEFS_ZONE_OPEN) ||
69  	    (z->z_wpoffset > 0 && z->z_wpoffset < z->z_capacity)) {
70  		if (!(z->z_flags & ZONEFS_ZONE_ACTIVE)) {
71  			z->z_flags |= ZONEFS_ZONE_ACTIVE;
72  			atomic_inc(&sbi->s_active_seq_files);
73  		}
74  		return;
75  	}
76  
77  out:
78  	/* The zone is not active. If it was, update the active count */
79  	if (z->z_flags & ZONEFS_ZONE_ACTIVE) {
80  		z->z_flags &= ~ZONEFS_ZONE_ACTIVE;
81  		atomic_dec(&sbi->s_active_seq_files);
82  	}
83  }
84  
85  /*
86   * Manage the active zone count. Called with zi->i_truncate_mutex held.
87   */
88  void zonefs_inode_account_active(struct inode *inode)
89  {
90  	lockdep_assert_held(&ZONEFS_I(inode)->i_truncate_mutex);
91  
92  	return zonefs_account_active(inode->i_sb, zonefs_inode_zone(inode));
93  }
94  
95  /*
96   * Execute a zone management operation.
97   */
98  static int zonefs_zone_mgmt(struct super_block *sb,
99  			    struct zonefs_zone *z, enum req_op op)
100  {
101  	int ret;
102  
103  	/*
104  	 * With ZNS drives, closing an explicitly open zone that has not been
105  	 * written will change the zone state to "closed", that is, the zone
106  	 * will remain active. Since this can then cause failure of explicit
107  	 * open operation on other zones if the drive active zone resources
108  	 * are exceeded, make sure that the zone does not remain active by
109  	 * resetting it.
110  	 */
111  	if (op == REQ_OP_ZONE_CLOSE && !z->z_wpoffset)
112  		op = REQ_OP_ZONE_RESET;
113  
114  	trace_zonefs_zone_mgmt(sb, z, op);
115  	ret = blkdev_zone_mgmt(sb->s_bdev, op, z->z_sector,
116  			       z->z_size >> SECTOR_SHIFT, GFP_NOFS);
117  	if (ret) {
118  		zonefs_err(sb,
119  			   "Zone management operation %s at %llu failed %d\n",
120  			   blk_op_str(op), z->z_sector, ret);
121  		return ret;
122  	}
123  
124  	return 0;
125  }
126  
127  int zonefs_inode_zone_mgmt(struct inode *inode, enum req_op op)
128  {
129  	lockdep_assert_held(&ZONEFS_I(inode)->i_truncate_mutex);
130  
131  	return zonefs_zone_mgmt(inode->i_sb, zonefs_inode_zone(inode), op);
132  }
133  
134  void zonefs_i_size_write(struct inode *inode, loff_t isize)
135  {
136  	struct zonefs_zone *z = zonefs_inode_zone(inode);
137  
138  	i_size_write(inode, isize);
139  
140  	/*
141  	 * A full zone is no longer open/active and does not need
142  	 * explicit closing.
143  	 */
144  	if (isize >= z->z_capacity) {
145  		struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);
146  
147  		if (z->z_flags & ZONEFS_ZONE_ACTIVE)
148  			atomic_dec(&sbi->s_active_seq_files);
149  		z->z_flags &= ~(ZONEFS_ZONE_OPEN | ZONEFS_ZONE_ACTIVE);
150  	}
151  }
152  
153  void zonefs_update_stats(struct inode *inode, loff_t new_isize)
154  {
155  	struct super_block *sb = inode->i_sb;
156  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
157  	loff_t old_isize = i_size_read(inode);
158  	loff_t nr_blocks;
159  
160  	if (new_isize == old_isize)
161  		return;
162  
163  	spin_lock(&sbi->s_lock);
164  
165  	/*
166  	 * This may be called for an update after an IO error.
167  	 * So beware of the values seen.
168  	 */
169  	if (new_isize < old_isize) {
170  		nr_blocks = (old_isize - new_isize) >> sb->s_blocksize_bits;
171  		if (sbi->s_used_blocks > nr_blocks)
172  			sbi->s_used_blocks -= nr_blocks;
173  		else
174  			sbi->s_used_blocks = 0;
175  	} else {
176  		sbi->s_used_blocks +=
177  			(new_isize - old_isize) >> sb->s_blocksize_bits;
178  		if (sbi->s_used_blocks > sbi->s_blocks)
179  			sbi->s_used_blocks = sbi->s_blocks;
180  	}
181  
182  	spin_unlock(&sbi->s_lock);
183  }
184  
185  /*
186   * Check a zone condition. Return the amount of written (and still readable)
187   * data in the zone.
188   */
189  static loff_t zonefs_check_zone_condition(struct super_block *sb,
190  					  struct zonefs_zone *z,
191  					  struct blk_zone *zone)
192  {
193  	switch (zone->cond) {
194  	case BLK_ZONE_COND_OFFLINE:
195  		zonefs_warn(sb, "Zone %llu: offline zone\n",
196  			    z->z_sector);
197  		z->z_flags |= ZONEFS_ZONE_OFFLINE;
198  		return 0;
199  	case BLK_ZONE_COND_READONLY:
200  		/*
201  		 * The write pointer of read-only zones is invalid, so we cannot
202  		 * determine the zone wpoffset (inode size). We thus keep the
203  		 * zone wpoffset as is, which leads to an empty file
204  		 * (wpoffset == 0) on mount. For a runtime error, this keeps
205  		 * the inode size as it was when last updated so that the user
206  		 * can recover data.
207  		 */
208  		zonefs_warn(sb, "Zone %llu: read-only zone\n",
209  			    z->z_sector);
210  		z->z_flags |= ZONEFS_ZONE_READONLY;
211  		if (zonefs_zone_is_cnv(z))
212  			return z->z_capacity;
213  		return z->z_wpoffset;
214  	case BLK_ZONE_COND_FULL:
215  		/* The write pointer of full zones is invalid. */
216  		return z->z_capacity;
217  	default:
218  		if (zonefs_zone_is_cnv(z))
219  			return z->z_capacity;
220  		return (zone->wp - zone->start) << SECTOR_SHIFT;
221  	}
222  }
223  
224  /*
225   * Check a zone condition and adjust its inode access permissions for
226   * offline and readonly zones.
227   */
228  static void zonefs_inode_update_mode(struct inode *inode)
229  {
230  	struct zonefs_zone *z = zonefs_inode_zone(inode);
231  
232  	if (z->z_flags & ZONEFS_ZONE_OFFLINE) {
233  		/* Offline zones cannot be read nor written */
234  		inode->i_flags |= S_IMMUTABLE;
235  		inode->i_mode &= ~0777;
236  	} else if (z->z_flags & ZONEFS_ZONE_READONLY) {
237  		/* Readonly zones cannot be written */
238  		inode->i_flags |= S_IMMUTABLE;
239  		if (z->z_flags & ZONEFS_ZONE_INIT_MODE)
240  			inode->i_mode &= ~0777;
241  		else
242  			inode->i_mode &= ~0222;
243  	}
244  
245  	z->z_flags &= ~ZONEFS_ZONE_INIT_MODE;
246  	z->z_mode = inode->i_mode;
247  }
248  
249  struct zonefs_ioerr_data {
250  	struct inode	*inode;
251  	bool		write;
252  };
253  
254  static int zonefs_io_error_cb(struct blk_zone *zone, unsigned int idx,
255  			      void *data)
256  {
257  	struct zonefs_ioerr_data *err = data;
258  	struct inode *inode = err->inode;
259  	struct zonefs_zone *z = zonefs_inode_zone(inode);
260  	struct super_block *sb = inode->i_sb;
261  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
262  	loff_t isize, data_size;
263  
264  	/*
265  	 * Check the zone condition: if the zone is not "bad" (offline or
266  	 * read-only), read errors are simply signaled to the IO issuer as long
267  	 * as there is no inconsistency between the inode size and the amount of
268  	 * data writen in the zone (data_size).
269  	 */
270  	data_size = zonefs_check_zone_condition(sb, z, zone);
271  	isize = i_size_read(inode);
272  	if (!(z->z_flags & (ZONEFS_ZONE_READONLY | ZONEFS_ZONE_OFFLINE)) &&
273  	    !err->write && isize == data_size)
274  		return 0;
275  
276  	/*
277  	 * At this point, we detected either a bad zone or an inconsistency
278  	 * between the inode size and the amount of data written in the zone.
279  	 * For the latter case, the cause may be a write IO error or an external
280  	 * action on the device. Two error patterns exist:
281  	 * 1) The inode size is lower than the amount of data in the zone:
282  	 *    a write operation partially failed and data was writen at the end
283  	 *    of the file. This can happen in the case of a large direct IO
284  	 *    needing several BIOs and/or write requests to be processed.
285  	 * 2) The inode size is larger than the amount of data in the zone:
286  	 *    this can happen with a deferred write error with the use of the
287  	 *    device side write cache after getting successful write IO
288  	 *    completions. Other possibilities are (a) an external corruption,
289  	 *    e.g. an application reset the zone directly, or (b) the device
290  	 *    has a serious problem (e.g. firmware bug).
291  	 *
292  	 * In all cases, warn about inode size inconsistency and handle the
293  	 * IO error according to the zone condition and to the mount options.
294  	 */
295  	if (zonefs_zone_is_seq(z) && isize != data_size)
296  		zonefs_warn(sb,
297  			    "inode %lu: invalid size %lld (should be %lld)\n",
298  			    inode->i_ino, isize, data_size);
299  
300  	/*
301  	 * First handle bad zones signaled by hardware. The mount options
302  	 * errors=zone-ro and errors=zone-offline result in changing the
303  	 * zone condition to read-only and offline respectively, as if the
304  	 * condition was signaled by the hardware.
305  	 */
306  	if ((z->z_flags & ZONEFS_ZONE_OFFLINE) ||
307  	    (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL)) {
308  		zonefs_warn(sb, "inode %lu: read/write access disabled\n",
309  			    inode->i_ino);
310  		if (!(z->z_flags & ZONEFS_ZONE_OFFLINE))
311  			z->z_flags |= ZONEFS_ZONE_OFFLINE;
312  		zonefs_inode_update_mode(inode);
313  		data_size = 0;
314  	} else if ((z->z_flags & ZONEFS_ZONE_READONLY) ||
315  		   (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO)) {
316  		zonefs_warn(sb, "inode %lu: write access disabled\n",
317  			    inode->i_ino);
318  		if (!(z->z_flags & ZONEFS_ZONE_READONLY))
319  			z->z_flags |= ZONEFS_ZONE_READONLY;
320  		zonefs_inode_update_mode(inode);
321  		data_size = isize;
322  	} else if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO &&
323  		   data_size > isize) {
324  		/* Do not expose garbage data */
325  		data_size = isize;
326  	}
327  
328  	/*
329  	 * If the filesystem is mounted with the explicit-open mount option, we
330  	 * need to clear the ZONEFS_ZONE_OPEN flag if the zone transitioned to
331  	 * the read-only or offline condition, to avoid attempting an explicit
332  	 * close of the zone when the inode file is closed.
333  	 */
334  	if ((sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) &&
335  	    (z->z_flags & (ZONEFS_ZONE_READONLY | ZONEFS_ZONE_OFFLINE)))
336  		z->z_flags &= ~ZONEFS_ZONE_OPEN;
337  
338  	/*
339  	 * If error=remount-ro was specified, any error result in remounting
340  	 * the volume as read-only.
341  	 */
342  	if ((sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO) && !sb_rdonly(sb)) {
343  		zonefs_warn(sb, "remounting filesystem read-only\n");
344  		sb->s_flags |= SB_RDONLY;
345  	}
346  
347  	/*
348  	 * Update block usage stats and the inode size  to prevent access to
349  	 * invalid data.
350  	 */
351  	zonefs_update_stats(inode, data_size);
352  	zonefs_i_size_write(inode, data_size);
353  	z->z_wpoffset = data_size;
354  	zonefs_inode_account_active(inode);
355  
356  	return 0;
357  }
358  
359  /*
360   * When an file IO error occurs, check the file zone to see if there is a change
361   * in the zone condition (e.g. offline or read-only). For a failed write to a
362   * sequential zone, the zone write pointer position must also be checked to
363   * eventually correct the file size and zonefs inode write pointer offset
364   * (which can be out of sync with the drive due to partial write failures).
365   */
366  void __zonefs_io_error(struct inode *inode, bool write)
367  {
368  	struct zonefs_zone *z = zonefs_inode_zone(inode);
369  	struct super_block *sb = inode->i_sb;
370  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
371  	unsigned int noio_flag;
372  	unsigned int nr_zones = 1;
373  	struct zonefs_ioerr_data err = {
374  		.inode = inode,
375  		.write = write,
376  	};
377  	int ret;
378  
379  	/*
380  	 * The only files that have more than one zone are conventional zone
381  	 * files with aggregated conventional zones, for which the inode zone
382  	 * size is always larger than the device zone size.
383  	 */
384  	if (z->z_size > bdev_zone_sectors(sb->s_bdev))
385  		nr_zones = z->z_size >>
386  			(sbi->s_zone_sectors_shift + SECTOR_SHIFT);
387  
388  	/*
389  	 * Memory allocations in blkdev_report_zones() can trigger a memory
390  	 * reclaim which may in turn cause a recursion into zonefs as well as
391  	 * struct request allocations for the same device. The former case may
392  	 * end up in a deadlock on the inode truncate mutex, while the latter
393  	 * may prevent IO forward progress. Executing the report zones under
394  	 * the GFP_NOIO context avoids both problems.
395  	 */
396  	noio_flag = memalloc_noio_save();
397  	ret = blkdev_report_zones(sb->s_bdev, z->z_sector, nr_zones,
398  				  zonefs_io_error_cb, &err);
399  	if (ret != nr_zones)
400  		zonefs_err(sb, "Get inode %lu zone information failed %d\n",
401  			   inode->i_ino, ret);
402  	memalloc_noio_restore(noio_flag);
403  }
404  
405  static struct kmem_cache *zonefs_inode_cachep;
406  
407  static struct inode *zonefs_alloc_inode(struct super_block *sb)
408  {
409  	struct zonefs_inode_info *zi;
410  
411  	zi = alloc_inode_sb(sb, zonefs_inode_cachep, GFP_KERNEL);
412  	if (!zi)
413  		return NULL;
414  
415  	inode_init_once(&zi->i_vnode);
416  	mutex_init(&zi->i_truncate_mutex);
417  	zi->i_wr_refcnt = 0;
418  
419  	return &zi->i_vnode;
420  }
421  
422  static void zonefs_free_inode(struct inode *inode)
423  {
424  	kmem_cache_free(zonefs_inode_cachep, ZONEFS_I(inode));
425  }
426  
427  /*
428   * File system stat.
429   */
430  static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf)
431  {
432  	struct super_block *sb = dentry->d_sb;
433  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
434  	enum zonefs_ztype t;
435  
436  	buf->f_type = ZONEFS_MAGIC;
437  	buf->f_bsize = sb->s_blocksize;
438  	buf->f_namelen = ZONEFS_NAME_MAX;
439  
440  	spin_lock(&sbi->s_lock);
441  
442  	buf->f_blocks = sbi->s_blocks;
443  	if (WARN_ON(sbi->s_used_blocks > sbi->s_blocks))
444  		buf->f_bfree = 0;
445  	else
446  		buf->f_bfree = buf->f_blocks - sbi->s_used_blocks;
447  	buf->f_bavail = buf->f_bfree;
448  
449  	for (t = 0; t < ZONEFS_ZTYPE_MAX; t++) {
450  		if (sbi->s_zgroup[t].g_nr_zones)
451  			buf->f_files += sbi->s_zgroup[t].g_nr_zones + 1;
452  	}
453  	buf->f_ffree = 0;
454  
455  	spin_unlock(&sbi->s_lock);
456  
457  	buf->f_fsid = uuid_to_fsid(sbi->s_uuid.b);
458  
459  	return 0;
460  }
461  
462  enum {
463  	Opt_errors_ro, Opt_errors_zro, Opt_errors_zol, Opt_errors_repair,
464  	Opt_explicit_open, Opt_err,
465  };
466  
467  static const match_table_t tokens = {
468  	{ Opt_errors_ro,	"errors=remount-ro"},
469  	{ Opt_errors_zro,	"errors=zone-ro"},
470  	{ Opt_errors_zol,	"errors=zone-offline"},
471  	{ Opt_errors_repair,	"errors=repair"},
472  	{ Opt_explicit_open,	"explicit-open" },
473  	{ Opt_err,		NULL}
474  };
475  
476  static int zonefs_parse_options(struct super_block *sb, char *options)
477  {
478  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
479  	substring_t args[MAX_OPT_ARGS];
480  	char *p;
481  
482  	if (!options)
483  		return 0;
484  
485  	while ((p = strsep(&options, ",")) != NULL) {
486  		int token;
487  
488  		if (!*p)
489  			continue;
490  
491  		token = match_token(p, tokens, args);
492  		switch (token) {
493  		case Opt_errors_ro:
494  			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
495  			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_RO;
496  			break;
497  		case Opt_errors_zro:
498  			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
499  			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_ZRO;
500  			break;
501  		case Opt_errors_zol:
502  			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
503  			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_ZOL;
504  			break;
505  		case Opt_errors_repair:
506  			sbi->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;
507  			sbi->s_mount_opts |= ZONEFS_MNTOPT_ERRORS_REPAIR;
508  			break;
509  		case Opt_explicit_open:
510  			sbi->s_mount_opts |= ZONEFS_MNTOPT_EXPLICIT_OPEN;
511  			break;
512  		default:
513  			return -EINVAL;
514  		}
515  	}
516  
517  	return 0;
518  }
519  
520  static int zonefs_show_options(struct seq_file *seq, struct dentry *root)
521  {
522  	struct zonefs_sb_info *sbi = ZONEFS_SB(root->d_sb);
523  
524  	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO)
525  		seq_puts(seq, ",errors=remount-ro");
526  	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO)
527  		seq_puts(seq, ",errors=zone-ro");
528  	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL)
529  		seq_puts(seq, ",errors=zone-offline");
530  	if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_REPAIR)
531  		seq_puts(seq, ",errors=repair");
532  
533  	return 0;
534  }
535  
536  static int zonefs_remount(struct super_block *sb, int *flags, char *data)
537  {
538  	sync_filesystem(sb);
539  
540  	return zonefs_parse_options(sb, data);
541  }
542  
543  static int zonefs_inode_setattr(struct mnt_idmap *idmap,
544  				struct dentry *dentry, struct iattr *iattr)
545  {
546  	struct inode *inode = d_inode(dentry);
547  	int ret;
548  
549  	if (unlikely(IS_IMMUTABLE(inode)))
550  		return -EPERM;
551  
552  	ret = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
553  	if (ret)
554  		return ret;
555  
556  	/*
557  	 * Since files and directories cannot be created nor deleted, do not
558  	 * allow setting any write attributes on the sub-directories grouping
559  	 * files by zone type.
560  	 */
561  	if ((iattr->ia_valid & ATTR_MODE) && S_ISDIR(inode->i_mode) &&
562  	    (iattr->ia_mode & 0222))
563  		return -EPERM;
564  
565  	if (((iattr->ia_valid & ATTR_UID) &&
566  	     !uid_eq(iattr->ia_uid, inode->i_uid)) ||
567  	    ((iattr->ia_valid & ATTR_GID) &&
568  	     !gid_eq(iattr->ia_gid, inode->i_gid))) {
569  		ret = dquot_transfer(&nop_mnt_idmap, inode, iattr);
570  		if (ret)
571  			return ret;
572  	}
573  
574  	if (iattr->ia_valid & ATTR_SIZE) {
575  		ret = zonefs_file_truncate(inode, iattr->ia_size);
576  		if (ret)
577  			return ret;
578  	}
579  
580  	setattr_copy(&nop_mnt_idmap, inode, iattr);
581  
582  	if (S_ISREG(inode->i_mode)) {
583  		struct zonefs_zone *z = zonefs_inode_zone(inode);
584  
585  		z->z_mode = inode->i_mode;
586  		z->z_uid = inode->i_uid;
587  		z->z_gid = inode->i_gid;
588  	}
589  
590  	return 0;
591  }
592  
593  static const struct inode_operations zonefs_file_inode_operations = {
594  	.setattr	= zonefs_inode_setattr,
595  };
596  
597  static long zonefs_fname_to_fno(const struct qstr *fname)
598  {
599  	const char *name = fname->name;
600  	unsigned int len = fname->len;
601  	long fno = 0, shift = 1;
602  	const char *rname;
603  	char c = *name;
604  	unsigned int i;
605  
606  	/*
607  	 * File names are always a base-10 number string without any
608  	 * leading 0s.
609  	 */
610  	if (!isdigit(c))
611  		return -ENOENT;
612  
613  	if (len > 1 && c == '0')
614  		return -ENOENT;
615  
616  	if (len == 1)
617  		return c - '0';
618  
619  	for (i = 0, rname = name + len - 1; i < len; i++, rname--) {
620  		c = *rname;
621  		if (!isdigit(c))
622  			return -ENOENT;
623  		fno += (c - '0') * shift;
624  		shift *= 10;
625  	}
626  
627  	return fno;
628  }
629  
630  static struct inode *zonefs_get_file_inode(struct inode *dir,
631  					   struct dentry *dentry)
632  {
633  	struct zonefs_zone_group *zgroup = dir->i_private;
634  	struct super_block *sb = dir->i_sb;
635  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
636  	struct zonefs_zone *z;
637  	struct inode *inode;
638  	ino_t ino;
639  	long fno;
640  
641  	/* Get the file number from the file name */
642  	fno = zonefs_fname_to_fno(&dentry->d_name);
643  	if (fno < 0)
644  		return ERR_PTR(fno);
645  
646  	if (!zgroup->g_nr_zones || fno >= zgroup->g_nr_zones)
647  		return ERR_PTR(-ENOENT);
648  
649  	z = &zgroup->g_zones[fno];
650  	ino = z->z_sector >> sbi->s_zone_sectors_shift;
651  	inode = iget_locked(sb, ino);
652  	if (!inode)
653  		return ERR_PTR(-ENOMEM);
654  	if (!(inode->i_state & I_NEW)) {
655  		WARN_ON_ONCE(inode->i_private != z);
656  		return inode;
657  	}
658  
659  	inode->i_ino = ino;
660  	inode->i_mode = z->z_mode;
661  	inode->i_ctime = inode->i_mtime = inode->i_atime = dir->i_ctime;
662  	inode->i_uid = z->z_uid;
663  	inode->i_gid = z->z_gid;
664  	inode->i_size = z->z_wpoffset;
665  	inode->i_blocks = z->z_capacity >> SECTOR_SHIFT;
666  	inode->i_private = z;
667  
668  	inode->i_op = &zonefs_file_inode_operations;
669  	inode->i_fop = &zonefs_file_operations;
670  	inode->i_mapping->a_ops = &zonefs_file_aops;
671  
672  	/* Update the inode access rights depending on the zone condition */
673  	zonefs_inode_update_mode(inode);
674  
675  	unlock_new_inode(inode);
676  
677  	return inode;
678  }
679  
680  static struct inode *zonefs_get_zgroup_inode(struct super_block *sb,
681  					     enum zonefs_ztype ztype)
682  {
683  	struct inode *root = d_inode(sb->s_root);
684  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
685  	struct inode *inode;
686  	ino_t ino = bdev_nr_zones(sb->s_bdev) + ztype + 1;
687  
688  	inode = iget_locked(sb, ino);
689  	if (!inode)
690  		return ERR_PTR(-ENOMEM);
691  	if (!(inode->i_state & I_NEW))
692  		return inode;
693  
694  	inode->i_ino = ino;
695  	inode_init_owner(&nop_mnt_idmap, inode, root, S_IFDIR | 0555);
696  	inode->i_size = sbi->s_zgroup[ztype].g_nr_zones;
697  	inode->i_ctime = inode->i_mtime = inode->i_atime = root->i_ctime;
698  	inode->i_private = &sbi->s_zgroup[ztype];
699  	set_nlink(inode, 2);
700  
701  	inode->i_op = &zonefs_dir_inode_operations;
702  	inode->i_fop = &zonefs_dir_operations;
703  
704  	unlock_new_inode(inode);
705  
706  	return inode;
707  }
708  
709  
710  static struct inode *zonefs_get_dir_inode(struct inode *dir,
711  					  struct dentry *dentry)
712  {
713  	struct super_block *sb = dir->i_sb;
714  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
715  	const char *name = dentry->d_name.name;
716  	enum zonefs_ztype ztype;
717  
718  	/*
719  	 * We only need to check for the "seq" directory and
720  	 * the "cnv" directory if we have conventional zones.
721  	 */
722  	if (dentry->d_name.len != 3)
723  		return ERR_PTR(-ENOENT);
724  
725  	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
726  		if (sbi->s_zgroup[ztype].g_nr_zones &&
727  		    memcmp(name, zonefs_zgroup_name(ztype), 3) == 0)
728  			break;
729  	}
730  	if (ztype == ZONEFS_ZTYPE_MAX)
731  		return ERR_PTR(-ENOENT);
732  
733  	return zonefs_get_zgroup_inode(sb, ztype);
734  }
735  
736  static struct dentry *zonefs_lookup(struct inode *dir, struct dentry *dentry,
737  				    unsigned int flags)
738  {
739  	struct inode *inode;
740  
741  	if (dentry->d_name.len > ZONEFS_NAME_MAX)
742  		return ERR_PTR(-ENAMETOOLONG);
743  
744  	if (dir == d_inode(dir->i_sb->s_root))
745  		inode = zonefs_get_dir_inode(dir, dentry);
746  	else
747  		inode = zonefs_get_file_inode(dir, dentry);
748  	if (IS_ERR(inode))
749  		return ERR_CAST(inode);
750  
751  	return d_splice_alias(inode, dentry);
752  }
753  
754  static int zonefs_readdir_root(struct file *file, struct dir_context *ctx)
755  {
756  	struct inode *inode = file_inode(file);
757  	struct super_block *sb = inode->i_sb;
758  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
759  	enum zonefs_ztype ztype = ZONEFS_ZTYPE_CNV;
760  	ino_t base_ino = bdev_nr_zones(sb->s_bdev) + 1;
761  
762  	if (ctx->pos >= inode->i_size)
763  		return 0;
764  
765  	if (!dir_emit_dots(file, ctx))
766  		return 0;
767  
768  	if (ctx->pos == 2) {
769  		if (!sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones)
770  			ztype = ZONEFS_ZTYPE_SEQ;
771  
772  		if (!dir_emit(ctx, zonefs_zgroup_name(ztype), 3,
773  			      base_ino + ztype, DT_DIR))
774  			return 0;
775  		ctx->pos++;
776  	}
777  
778  	if (ctx->pos == 3 && ztype != ZONEFS_ZTYPE_SEQ) {
779  		ztype = ZONEFS_ZTYPE_SEQ;
780  		if (!dir_emit(ctx, zonefs_zgroup_name(ztype), 3,
781  			      base_ino + ztype, DT_DIR))
782  			return 0;
783  		ctx->pos++;
784  	}
785  
786  	return 0;
787  }
788  
789  static int zonefs_readdir_zgroup(struct file *file,
790  				 struct dir_context *ctx)
791  {
792  	struct inode *inode = file_inode(file);
793  	struct zonefs_zone_group *zgroup = inode->i_private;
794  	struct super_block *sb = inode->i_sb;
795  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
796  	struct zonefs_zone *z;
797  	int fname_len;
798  	char *fname;
799  	ino_t ino;
800  	int f;
801  
802  	/*
803  	 * The size of zone group directories is equal to the number
804  	 * of zone files in the group and does note include the "." and
805  	 * ".." entries. Hence the "+ 2" here.
806  	 */
807  	if (ctx->pos >= inode->i_size + 2)
808  		return 0;
809  
810  	if (!dir_emit_dots(file, ctx))
811  		return 0;
812  
813  	fname = kmalloc(ZONEFS_NAME_MAX, GFP_KERNEL);
814  	if (!fname)
815  		return -ENOMEM;
816  
817  	for (f = ctx->pos - 2; f < zgroup->g_nr_zones; f++) {
818  		z = &zgroup->g_zones[f];
819  		ino = z->z_sector >> sbi->s_zone_sectors_shift;
820  		fname_len = snprintf(fname, ZONEFS_NAME_MAX - 1, "%u", f);
821  		if (!dir_emit(ctx, fname, fname_len, ino, DT_REG))
822  			break;
823  		ctx->pos++;
824  	}
825  
826  	kfree(fname);
827  
828  	return 0;
829  }
830  
831  static int zonefs_readdir(struct file *file, struct dir_context *ctx)
832  {
833  	struct inode *inode = file_inode(file);
834  
835  	if (inode == d_inode(inode->i_sb->s_root))
836  		return zonefs_readdir_root(file, ctx);
837  
838  	return zonefs_readdir_zgroup(file, ctx);
839  }
840  
841  const struct inode_operations zonefs_dir_inode_operations = {
842  	.lookup		= zonefs_lookup,
843  	.setattr	= zonefs_inode_setattr,
844  };
845  
846  const struct file_operations zonefs_dir_operations = {
847  	.llseek		= generic_file_llseek,
848  	.read		= generic_read_dir,
849  	.iterate_shared	= zonefs_readdir,
850  };
851  
852  struct zonefs_zone_data {
853  	struct super_block	*sb;
854  	unsigned int		nr_zones[ZONEFS_ZTYPE_MAX];
855  	sector_t		cnv_zone_start;
856  	struct blk_zone		*zones;
857  };
858  
859  static int zonefs_get_zone_info_cb(struct blk_zone *zone, unsigned int idx,
860  				   void *data)
861  {
862  	struct zonefs_zone_data *zd = data;
863  	struct super_block *sb = zd->sb;
864  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
865  
866  	/*
867  	 * We do not care about the first zone: it contains the super block
868  	 * and not exposed as a file.
869  	 */
870  	if (!idx)
871  		return 0;
872  
873  	/*
874  	 * Count the number of zones that will be exposed as files.
875  	 * For sequential zones, we always have as many files as zones.
876  	 * FOr conventional zones, the number of files depends on if we have
877  	 * conventional zones aggregation enabled.
878  	 */
879  	switch (zone->type) {
880  	case BLK_ZONE_TYPE_CONVENTIONAL:
881  		if (sbi->s_features & ZONEFS_F_AGGRCNV) {
882  			/* One file per set of contiguous conventional zones */
883  			if (!(sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones) ||
884  			    zone->start != zd->cnv_zone_start)
885  				sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones++;
886  			zd->cnv_zone_start = zone->start + zone->len;
887  		} else {
888  			/* One file per zone */
889  			sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones++;
890  		}
891  		break;
892  	case BLK_ZONE_TYPE_SEQWRITE_REQ:
893  	case BLK_ZONE_TYPE_SEQWRITE_PREF:
894  		sbi->s_zgroup[ZONEFS_ZTYPE_SEQ].g_nr_zones++;
895  		break;
896  	default:
897  		zonefs_err(zd->sb, "Unsupported zone type 0x%x\n",
898  			   zone->type);
899  		return -EIO;
900  	}
901  
902  	memcpy(&zd->zones[idx], zone, sizeof(struct blk_zone));
903  
904  	return 0;
905  }
906  
907  static int zonefs_get_zone_info(struct zonefs_zone_data *zd)
908  {
909  	struct block_device *bdev = zd->sb->s_bdev;
910  	int ret;
911  
912  	zd->zones = kvcalloc(bdev_nr_zones(bdev), sizeof(struct blk_zone),
913  			     GFP_KERNEL);
914  	if (!zd->zones)
915  		return -ENOMEM;
916  
917  	/* Get zones information from the device */
918  	ret = blkdev_report_zones(bdev, 0, BLK_ALL_ZONES,
919  				  zonefs_get_zone_info_cb, zd);
920  	if (ret < 0) {
921  		zonefs_err(zd->sb, "Zone report failed %d\n", ret);
922  		return ret;
923  	}
924  
925  	if (ret != bdev_nr_zones(bdev)) {
926  		zonefs_err(zd->sb, "Invalid zone report (%d/%u zones)\n",
927  			   ret, bdev_nr_zones(bdev));
928  		return -EIO;
929  	}
930  
931  	return 0;
932  }
933  
934  static inline void zonefs_free_zone_info(struct zonefs_zone_data *zd)
935  {
936  	kvfree(zd->zones);
937  }
938  
939  /*
940   * Create a zone group and populate it with zone files.
941   */
942  static int zonefs_init_zgroup(struct super_block *sb,
943  			      struct zonefs_zone_data *zd,
944  			      enum zonefs_ztype ztype)
945  {
946  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
947  	struct zonefs_zone_group *zgroup = &sbi->s_zgroup[ztype];
948  	struct blk_zone *zone, *next, *end;
949  	struct zonefs_zone *z;
950  	unsigned int n = 0;
951  	int ret;
952  
953  	/* Allocate the zone group. If it is empty, we have nothing to do. */
954  	if (!zgroup->g_nr_zones)
955  		return 0;
956  
957  	zgroup->g_zones = kvcalloc(zgroup->g_nr_zones,
958  				   sizeof(struct zonefs_zone), GFP_KERNEL);
959  	if (!zgroup->g_zones)
960  		return -ENOMEM;
961  
962  	/*
963  	 * Initialize the zone groups using the device zone information.
964  	 * We always skip the first zone as it contains the super block
965  	 * and is not use to back a file.
966  	 */
967  	end = zd->zones + bdev_nr_zones(sb->s_bdev);
968  	for (zone = &zd->zones[1]; zone < end; zone = next) {
969  
970  		next = zone + 1;
971  		if (zonefs_zone_type(zone) != ztype)
972  			continue;
973  
974  		if (WARN_ON_ONCE(n >= zgroup->g_nr_zones))
975  			return -EINVAL;
976  
977  		/*
978  		 * For conventional zones, contiguous zones can be aggregated
979  		 * together to form larger files. Note that this overwrites the
980  		 * length of the first zone of the set of contiguous zones
981  		 * aggregated together. If one offline or read-only zone is
982  		 * found, assume that all zones aggregated have the same
983  		 * condition.
984  		 */
985  		if (ztype == ZONEFS_ZTYPE_CNV &&
986  		    (sbi->s_features & ZONEFS_F_AGGRCNV)) {
987  			for (; next < end; next++) {
988  				if (zonefs_zone_type(next) != ztype)
989  					break;
990  				zone->len += next->len;
991  				zone->capacity += next->capacity;
992  				if (next->cond == BLK_ZONE_COND_READONLY &&
993  				    zone->cond != BLK_ZONE_COND_OFFLINE)
994  					zone->cond = BLK_ZONE_COND_READONLY;
995  				else if (next->cond == BLK_ZONE_COND_OFFLINE)
996  					zone->cond = BLK_ZONE_COND_OFFLINE;
997  			}
998  		}
999  
1000  		z = &zgroup->g_zones[n];
1001  		if (ztype == ZONEFS_ZTYPE_CNV)
1002  			z->z_flags |= ZONEFS_ZONE_CNV;
1003  		z->z_sector = zone->start;
1004  		z->z_size = zone->len << SECTOR_SHIFT;
1005  		if (z->z_size > bdev_zone_sectors(sb->s_bdev) << SECTOR_SHIFT &&
1006  		    !(sbi->s_features & ZONEFS_F_AGGRCNV)) {
1007  			zonefs_err(sb,
1008  				"Invalid zone size %llu (device zone sectors %llu)\n",
1009  				z->z_size,
1010  				bdev_zone_sectors(sb->s_bdev) << SECTOR_SHIFT);
1011  			return -EINVAL;
1012  		}
1013  
1014  		z->z_capacity = min_t(loff_t, MAX_LFS_FILESIZE,
1015  				      zone->capacity << SECTOR_SHIFT);
1016  		z->z_wpoffset = zonefs_check_zone_condition(sb, z, zone);
1017  
1018  		z->z_mode = S_IFREG | sbi->s_perm;
1019  		z->z_uid = sbi->s_uid;
1020  		z->z_gid = sbi->s_gid;
1021  
1022  		/*
1023  		 * Let zonefs_inode_update_mode() know that we will need
1024  		 * special initialization of the inode mode the first time
1025  		 * it is accessed.
1026  		 */
1027  		z->z_flags |= ZONEFS_ZONE_INIT_MODE;
1028  
1029  		sb->s_maxbytes = max(z->z_capacity, sb->s_maxbytes);
1030  		sbi->s_blocks += z->z_capacity >> sb->s_blocksize_bits;
1031  		sbi->s_used_blocks += z->z_wpoffset >> sb->s_blocksize_bits;
1032  
1033  		/*
1034  		 * For sequential zones, make sure that any open zone is closed
1035  		 * first to ensure that the initial number of open zones is 0,
1036  		 * in sync with the open zone accounting done when the mount
1037  		 * option ZONEFS_MNTOPT_EXPLICIT_OPEN is used.
1038  		 */
1039  		if (ztype == ZONEFS_ZTYPE_SEQ &&
1040  		    (zone->cond == BLK_ZONE_COND_IMP_OPEN ||
1041  		     zone->cond == BLK_ZONE_COND_EXP_OPEN)) {
1042  			ret = zonefs_zone_mgmt(sb, z, REQ_OP_ZONE_CLOSE);
1043  			if (ret)
1044  				return ret;
1045  		}
1046  
1047  		zonefs_account_active(sb, z);
1048  
1049  		n++;
1050  	}
1051  
1052  	if (WARN_ON_ONCE(n != zgroup->g_nr_zones))
1053  		return -EINVAL;
1054  
1055  	zonefs_info(sb, "Zone group \"%s\" has %u file%s\n",
1056  		    zonefs_zgroup_name(ztype),
1057  		    zgroup->g_nr_zones,
1058  		    zgroup->g_nr_zones > 1 ? "s" : "");
1059  
1060  	return 0;
1061  }
1062  
1063  static void zonefs_free_zgroups(struct super_block *sb)
1064  {
1065  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1066  	enum zonefs_ztype ztype;
1067  
1068  	if (!sbi)
1069  		return;
1070  
1071  	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
1072  		kvfree(sbi->s_zgroup[ztype].g_zones);
1073  		sbi->s_zgroup[ztype].g_zones = NULL;
1074  	}
1075  }
1076  
1077  /*
1078   * Create a zone group and populate it with zone files.
1079   */
1080  static int zonefs_init_zgroups(struct super_block *sb)
1081  {
1082  	struct zonefs_zone_data zd;
1083  	enum zonefs_ztype ztype;
1084  	int ret;
1085  
1086  	/* First get the device zone information */
1087  	memset(&zd, 0, sizeof(struct zonefs_zone_data));
1088  	zd.sb = sb;
1089  	ret = zonefs_get_zone_info(&zd);
1090  	if (ret)
1091  		goto cleanup;
1092  
1093  	/* Allocate and initialize the zone groups */
1094  	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
1095  		ret = zonefs_init_zgroup(sb, &zd, ztype);
1096  		if (ret) {
1097  			zonefs_info(sb,
1098  				    "Zone group \"%s\" initialization failed\n",
1099  				    zonefs_zgroup_name(ztype));
1100  			break;
1101  		}
1102  	}
1103  
1104  cleanup:
1105  	zonefs_free_zone_info(&zd);
1106  	if (ret)
1107  		zonefs_free_zgroups(sb);
1108  
1109  	return ret;
1110  }
1111  
1112  /*
1113   * Read super block information from the device.
1114   */
1115  static int zonefs_read_super(struct super_block *sb)
1116  {
1117  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1118  	struct zonefs_super *super;
1119  	u32 crc, stored_crc;
1120  	struct page *page;
1121  	struct bio_vec bio_vec;
1122  	struct bio bio;
1123  	int ret;
1124  
1125  	page = alloc_page(GFP_KERNEL);
1126  	if (!page)
1127  		return -ENOMEM;
1128  
1129  	bio_init(&bio, sb->s_bdev, &bio_vec, 1, REQ_OP_READ);
1130  	bio.bi_iter.bi_sector = 0;
1131  	__bio_add_page(&bio, page, PAGE_SIZE, 0);
1132  
1133  	ret = submit_bio_wait(&bio);
1134  	if (ret)
1135  		goto free_page;
1136  
1137  	super = page_address(page);
1138  
1139  	ret = -EINVAL;
1140  	if (le32_to_cpu(super->s_magic) != ZONEFS_MAGIC)
1141  		goto free_page;
1142  
1143  	stored_crc = le32_to_cpu(super->s_crc);
1144  	super->s_crc = 0;
1145  	crc = crc32(~0U, (unsigned char *)super, sizeof(struct zonefs_super));
1146  	if (crc != stored_crc) {
1147  		zonefs_err(sb, "Invalid checksum (Expected 0x%08x, got 0x%08x)",
1148  			   crc, stored_crc);
1149  		goto free_page;
1150  	}
1151  
1152  	sbi->s_features = le64_to_cpu(super->s_features);
1153  	if (sbi->s_features & ~ZONEFS_F_DEFINED_FEATURES) {
1154  		zonefs_err(sb, "Unknown features set 0x%llx\n",
1155  			   sbi->s_features);
1156  		goto free_page;
1157  	}
1158  
1159  	if (sbi->s_features & ZONEFS_F_UID) {
1160  		sbi->s_uid = make_kuid(current_user_ns(),
1161  				       le32_to_cpu(super->s_uid));
1162  		if (!uid_valid(sbi->s_uid)) {
1163  			zonefs_err(sb, "Invalid UID feature\n");
1164  			goto free_page;
1165  		}
1166  	}
1167  
1168  	if (sbi->s_features & ZONEFS_F_GID) {
1169  		sbi->s_gid = make_kgid(current_user_ns(),
1170  				       le32_to_cpu(super->s_gid));
1171  		if (!gid_valid(sbi->s_gid)) {
1172  			zonefs_err(sb, "Invalid GID feature\n");
1173  			goto free_page;
1174  		}
1175  	}
1176  
1177  	if (sbi->s_features & ZONEFS_F_PERM)
1178  		sbi->s_perm = le32_to_cpu(super->s_perm);
1179  
1180  	if (memchr_inv(super->s_reserved, 0, sizeof(super->s_reserved))) {
1181  		zonefs_err(sb, "Reserved area is being used\n");
1182  		goto free_page;
1183  	}
1184  
1185  	import_uuid(&sbi->s_uuid, super->s_uuid);
1186  	ret = 0;
1187  
1188  free_page:
1189  	__free_page(page);
1190  
1191  	return ret;
1192  }
1193  
1194  static const struct super_operations zonefs_sops = {
1195  	.alloc_inode	= zonefs_alloc_inode,
1196  	.free_inode	= zonefs_free_inode,
1197  	.statfs		= zonefs_statfs,
1198  	.remount_fs	= zonefs_remount,
1199  	.show_options	= zonefs_show_options,
1200  };
1201  
1202  static int zonefs_get_zgroup_inodes(struct super_block *sb)
1203  {
1204  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1205  	struct inode *dir_inode;
1206  	enum zonefs_ztype ztype;
1207  
1208  	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
1209  		if (!sbi->s_zgroup[ztype].g_nr_zones)
1210  			continue;
1211  
1212  		dir_inode = zonefs_get_zgroup_inode(sb, ztype);
1213  		if (IS_ERR(dir_inode))
1214  			return PTR_ERR(dir_inode);
1215  
1216  		sbi->s_zgroup[ztype].g_inode = dir_inode;
1217  	}
1218  
1219  	return 0;
1220  }
1221  
1222  static void zonefs_release_zgroup_inodes(struct super_block *sb)
1223  {
1224  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1225  	enum zonefs_ztype ztype;
1226  
1227  	if (!sbi)
1228  		return;
1229  
1230  	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
1231  		if (sbi->s_zgroup[ztype].g_inode) {
1232  			iput(sbi->s_zgroup[ztype].g_inode);
1233  			sbi->s_zgroup[ztype].g_inode = NULL;
1234  		}
1235  	}
1236  }
1237  
1238  /*
1239   * Check that the device is zoned. If it is, get the list of zones and create
1240   * sub-directories and files according to the device zone configuration and
1241   * format options.
1242   */
1243  static int zonefs_fill_super(struct super_block *sb, void *data, int silent)
1244  {
1245  	struct zonefs_sb_info *sbi;
1246  	struct inode *inode;
1247  	enum zonefs_ztype ztype;
1248  	int ret;
1249  
1250  	if (!bdev_is_zoned(sb->s_bdev)) {
1251  		zonefs_err(sb, "Not a zoned block device\n");
1252  		return -EINVAL;
1253  	}
1254  
1255  	/*
1256  	 * Initialize super block information: the maximum file size is updated
1257  	 * when the zone files are created so that the format option
1258  	 * ZONEFS_F_AGGRCNV which increases the maximum file size of a file
1259  	 * beyond the zone size is taken into account.
1260  	 */
1261  	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
1262  	if (!sbi)
1263  		return -ENOMEM;
1264  
1265  	spin_lock_init(&sbi->s_lock);
1266  	sb->s_fs_info = sbi;
1267  	sb->s_magic = ZONEFS_MAGIC;
1268  	sb->s_maxbytes = 0;
1269  	sb->s_op = &zonefs_sops;
1270  	sb->s_time_gran	= 1;
1271  
1272  	/*
1273  	 * The block size is set to the device zone write granularity to ensure
1274  	 * that write operations are always aligned according to the device
1275  	 * interface constraints.
1276  	 */
1277  	sb_set_blocksize(sb, bdev_zone_write_granularity(sb->s_bdev));
1278  	sbi->s_zone_sectors_shift = ilog2(bdev_zone_sectors(sb->s_bdev));
1279  	sbi->s_uid = GLOBAL_ROOT_UID;
1280  	sbi->s_gid = GLOBAL_ROOT_GID;
1281  	sbi->s_perm = 0640;
1282  	sbi->s_mount_opts = ZONEFS_MNTOPT_ERRORS_RO;
1283  
1284  	atomic_set(&sbi->s_wro_seq_files, 0);
1285  	sbi->s_max_wro_seq_files = bdev_max_open_zones(sb->s_bdev);
1286  	atomic_set(&sbi->s_active_seq_files, 0);
1287  	sbi->s_max_active_seq_files = bdev_max_active_zones(sb->s_bdev);
1288  
1289  	ret = zonefs_read_super(sb);
1290  	if (ret)
1291  		return ret;
1292  
1293  	ret = zonefs_parse_options(sb, data);
1294  	if (ret)
1295  		return ret;
1296  
1297  	zonefs_info(sb, "Mounting %u zones", bdev_nr_zones(sb->s_bdev));
1298  
1299  	if (!sbi->s_max_wro_seq_files &&
1300  	    !sbi->s_max_active_seq_files &&
1301  	    sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) {
1302  		zonefs_info(sb,
1303  			"No open and active zone limits. Ignoring explicit_open mount option\n");
1304  		sbi->s_mount_opts &= ~ZONEFS_MNTOPT_EXPLICIT_OPEN;
1305  	}
1306  
1307  	/* Initialize the zone groups */
1308  	ret = zonefs_init_zgroups(sb);
1309  	if (ret)
1310  		goto cleanup;
1311  
1312  	/* Create the root directory inode */
1313  	ret = -ENOMEM;
1314  	inode = new_inode(sb);
1315  	if (!inode)
1316  		goto cleanup;
1317  
1318  	inode->i_ino = bdev_nr_zones(sb->s_bdev);
1319  	inode->i_mode = S_IFDIR | 0555;
1320  	inode->i_ctime = inode->i_mtime = inode->i_atime = current_time(inode);
1321  	inode->i_op = &zonefs_dir_inode_operations;
1322  	inode->i_fop = &zonefs_dir_operations;
1323  	inode->i_size = 2;
1324  	set_nlink(inode, 2);
1325  	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {
1326  		if (sbi->s_zgroup[ztype].g_nr_zones) {
1327  			inc_nlink(inode);
1328  			inode->i_size++;
1329  		}
1330  	}
1331  
1332  	sb->s_root = d_make_root(inode);
1333  	if (!sb->s_root)
1334  		goto cleanup;
1335  
1336  	/*
1337  	 * Take a reference on the zone groups directory inodes
1338  	 * to keep them in the inode cache.
1339  	 */
1340  	ret = zonefs_get_zgroup_inodes(sb);
1341  	if (ret)
1342  		goto cleanup;
1343  
1344  	ret = zonefs_sysfs_register(sb);
1345  	if (ret)
1346  		goto cleanup;
1347  
1348  	return 0;
1349  
1350  cleanup:
1351  	zonefs_release_zgroup_inodes(sb);
1352  	zonefs_free_zgroups(sb);
1353  
1354  	return ret;
1355  }
1356  
1357  static struct dentry *zonefs_mount(struct file_system_type *fs_type,
1358  				   int flags, const char *dev_name, void *data)
1359  {
1360  	return mount_bdev(fs_type, flags, dev_name, data, zonefs_fill_super);
1361  }
1362  
1363  static void zonefs_kill_super(struct super_block *sb)
1364  {
1365  	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
1366  
1367  	/* Release the reference on the zone group directory inodes */
1368  	zonefs_release_zgroup_inodes(sb);
1369  
1370  	kill_block_super(sb);
1371  
1372  	zonefs_sysfs_unregister(sb);
1373  	zonefs_free_zgroups(sb);
1374  	kfree(sbi);
1375  }
1376  
1377  /*
1378   * File system definition and registration.
1379   */
1380  static struct file_system_type zonefs_type = {
1381  	.owner		= THIS_MODULE,
1382  	.name		= "zonefs",
1383  	.mount		= zonefs_mount,
1384  	.kill_sb	= zonefs_kill_super,
1385  	.fs_flags	= FS_REQUIRES_DEV,
1386  };
1387  
1388  static int __init zonefs_init_inodecache(void)
1389  {
1390  	zonefs_inode_cachep = kmem_cache_create("zonefs_inode_cache",
1391  			sizeof(struct zonefs_inode_info), 0,
1392  			(SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT),
1393  			NULL);
1394  	if (zonefs_inode_cachep == NULL)
1395  		return -ENOMEM;
1396  	return 0;
1397  }
1398  
1399  static void zonefs_destroy_inodecache(void)
1400  {
1401  	/*
1402  	 * Make sure all delayed rcu free inodes are flushed before we
1403  	 * destroy the inode cache.
1404  	 */
1405  	rcu_barrier();
1406  	kmem_cache_destroy(zonefs_inode_cachep);
1407  }
1408  
1409  static int __init zonefs_init(void)
1410  {
1411  	int ret;
1412  
1413  	BUILD_BUG_ON(sizeof(struct zonefs_super) != ZONEFS_SUPER_SIZE);
1414  
1415  	ret = zonefs_file_bioset_init();
1416  	if (ret)
1417  		return ret;
1418  
1419  	ret = zonefs_init_inodecache();
1420  	if (ret)
1421  		goto destroy_bioset;
1422  
1423  	ret = zonefs_sysfs_init();
1424  	if (ret)
1425  		goto destroy_inodecache;
1426  
1427  	ret = register_filesystem(&zonefs_type);
1428  	if (ret)
1429  		goto sysfs_exit;
1430  
1431  	return 0;
1432  
1433  sysfs_exit:
1434  	zonefs_sysfs_exit();
1435  destroy_inodecache:
1436  	zonefs_destroy_inodecache();
1437  destroy_bioset:
1438  	zonefs_file_bioset_exit();
1439  
1440  	return ret;
1441  }
1442  
1443  static void __exit zonefs_exit(void)
1444  {
1445  	unregister_filesystem(&zonefs_type);
1446  	zonefs_sysfs_exit();
1447  	zonefs_destroy_inodecache();
1448  	zonefs_file_bioset_exit();
1449  }
1450  
1451  MODULE_AUTHOR("Damien Le Moal");
1452  MODULE_DESCRIPTION("Zone file system for zoned block devices");
1453  MODULE_LICENSE("GPL");
1454  MODULE_ALIAS_FS("zonefs");
1455  module_init(zonefs_init);
1456  module_exit(zonefs_exit);
1457