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brintos / linux-shallow public Read only

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1// SPDX-License-Identifier: GPL-2.02/*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/uio.h>19#include <linux/mman.h>20#include <linux/sched/mm.h>21#include <linux/crc32.h>22#include <linux/task_io_accounting_ops.h>23#include <linux/fs_parser.h>24#include <linux/fs_context.h>25 26#include "zonefs.h"27 28#define CREATE_TRACE_POINTS29#include "trace.h"30 31/*32 * Get the name of a zone group directory.33 */34static const char *zonefs_zgroup_name(enum zonefs_ztype ztype)35{36	switch (ztype) {37	case ZONEFS_ZTYPE_CNV:38		return "cnv";39	case ZONEFS_ZTYPE_SEQ:40		return "seq";41	default:42		WARN_ON_ONCE(1);43		return "???";44	}45}46 47/*48 * Manage the active zone count.49 */50static void zonefs_account_active(struct super_block *sb,51				  struct zonefs_zone *z)52{53	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);54 55	if (zonefs_zone_is_cnv(z))56		return;57 58	/*59	 * For zones that transitioned to the offline or readonly condition,60	 * we only need to clear the active state.61	 */62	if (z->z_flags & (ZONEFS_ZONE_OFFLINE | ZONEFS_ZONE_READONLY))63		goto out;64 65	/*66	 * If the zone is active, that is, if it is explicitly open or67	 * partially written, check if it was already accounted as active.68	 */69	if ((z->z_flags & ZONEFS_ZONE_OPEN) ||70	    (z->z_wpoffset > 0 && z->z_wpoffset < z->z_capacity)) {71		if (!(z->z_flags & ZONEFS_ZONE_ACTIVE)) {72			z->z_flags |= ZONEFS_ZONE_ACTIVE;73			atomic_inc(&sbi->s_active_seq_files);74		}75		return;76	}77 78out:79	/* The zone is not active. If it was, update the active count */80	if (z->z_flags & ZONEFS_ZONE_ACTIVE) {81		z->z_flags &= ~ZONEFS_ZONE_ACTIVE;82		atomic_dec(&sbi->s_active_seq_files);83	}84}85 86/*87 * Manage the active zone count. Called with zi->i_truncate_mutex held.88 */89void zonefs_inode_account_active(struct inode *inode)90{91	lockdep_assert_held(&ZONEFS_I(inode)->i_truncate_mutex);92 93	return zonefs_account_active(inode->i_sb, zonefs_inode_zone(inode));94}95 96/*97 * Execute a zone management operation.98 */99static int zonefs_zone_mgmt(struct super_block *sb,100			    struct zonefs_zone *z, enum req_op op)101{102	int ret;103 104	/*105	 * With ZNS drives, closing an explicitly open zone that has not been106	 * written will change the zone state to "closed", that is, the zone107	 * will remain active. Since this can then cause failure of explicit108	 * open operation on other zones if the drive active zone resources109	 * are exceeded, make sure that the zone does not remain active by110	 * resetting it.111	 */112	if (op == REQ_OP_ZONE_CLOSE && !z->z_wpoffset)113		op = REQ_OP_ZONE_RESET;114 115	trace_zonefs_zone_mgmt(sb, z, op);116	ret = blkdev_zone_mgmt(sb->s_bdev, op, z->z_sector,117			       z->z_size >> SECTOR_SHIFT);118	if (ret) {119		zonefs_err(sb,120			   "Zone management operation %s at %llu failed %d\n",121			   blk_op_str(op), z->z_sector, ret);122		return ret;123	}124 125	return 0;126}127 128int zonefs_inode_zone_mgmt(struct inode *inode, enum req_op op)129{130	lockdep_assert_held(&ZONEFS_I(inode)->i_truncate_mutex);131 132	return zonefs_zone_mgmt(inode->i_sb, zonefs_inode_zone(inode), op);133}134 135void zonefs_i_size_write(struct inode *inode, loff_t isize)136{137	struct zonefs_zone *z = zonefs_inode_zone(inode);138 139	i_size_write(inode, isize);140 141	/*142	 * A full zone is no longer open/active and does not need143	 * explicit closing.144	 */145	if (isize >= z->z_capacity) {146		struct zonefs_sb_info *sbi = ZONEFS_SB(inode->i_sb);147 148		if (z->z_flags & ZONEFS_ZONE_ACTIVE)149			atomic_dec(&sbi->s_active_seq_files);150		z->z_flags &= ~(ZONEFS_ZONE_OPEN | ZONEFS_ZONE_ACTIVE);151	}152}153 154void zonefs_update_stats(struct inode *inode, loff_t new_isize)155{156	struct super_block *sb = inode->i_sb;157	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);158	loff_t old_isize = i_size_read(inode);159	loff_t nr_blocks;160 161	if (new_isize == old_isize)162		return;163 164	spin_lock(&sbi->s_lock);165 166	/*167	 * This may be called for an update after an IO error.168	 * So beware of the values seen.169	 */170	if (new_isize < old_isize) {171		nr_blocks = (old_isize - new_isize) >> sb->s_blocksize_bits;172		if (sbi->s_used_blocks > nr_blocks)173			sbi->s_used_blocks -= nr_blocks;174		else175			sbi->s_used_blocks = 0;176	} else {177		sbi->s_used_blocks +=178			(new_isize - old_isize) >> sb->s_blocksize_bits;179		if (sbi->s_used_blocks > sbi->s_blocks)180			sbi->s_used_blocks = sbi->s_blocks;181	}182 183	spin_unlock(&sbi->s_lock);184}185 186/*187 * Check a zone condition. Return the amount of written (and still readable)188 * data in the zone.189 */190static loff_t zonefs_check_zone_condition(struct super_block *sb,191					  struct zonefs_zone *z,192					  struct blk_zone *zone)193{194	switch (zone->cond) {195	case BLK_ZONE_COND_OFFLINE:196		zonefs_warn(sb, "Zone %llu: offline zone\n",197			    z->z_sector);198		z->z_flags |= ZONEFS_ZONE_OFFLINE;199		return 0;200	case BLK_ZONE_COND_READONLY:201		/*202		 * The write pointer of read-only zones is invalid, so we cannot203		 * determine the zone wpoffset (inode size). We thus keep the204		 * zone wpoffset as is, which leads to an empty file205		 * (wpoffset == 0) on mount. For a runtime error, this keeps206		 * the inode size as it was when last updated so that the user207		 * can recover data.208		 */209		zonefs_warn(sb, "Zone %llu: read-only zone\n",210			    z->z_sector);211		z->z_flags |= ZONEFS_ZONE_READONLY;212		if (zonefs_zone_is_cnv(z))213			return z->z_capacity;214		return z->z_wpoffset;215	case BLK_ZONE_COND_FULL:216		/* The write pointer of full zones is invalid. */217		return z->z_capacity;218	default:219		if (zonefs_zone_is_cnv(z))220			return z->z_capacity;221		return (zone->wp - zone->start) << SECTOR_SHIFT;222	}223}224 225/*226 * Check a zone condition and adjust its inode access permissions for227 * offline and readonly zones.228 */229static void zonefs_inode_update_mode(struct inode *inode)230{231	struct zonefs_zone *z = zonefs_inode_zone(inode);232 233	if (z->z_flags & ZONEFS_ZONE_OFFLINE) {234		/* Offline zones cannot be read nor written */235		inode->i_flags |= S_IMMUTABLE;236		inode->i_mode &= ~0777;237	} else if (z->z_flags & ZONEFS_ZONE_READONLY) {238		/* Readonly zones cannot be written */239		inode->i_flags |= S_IMMUTABLE;240		if (z->z_flags & ZONEFS_ZONE_INIT_MODE)241			inode->i_mode &= ~0777;242		else243			inode->i_mode &= ~0222;244	}245 246	z->z_flags &= ~ZONEFS_ZONE_INIT_MODE;247	z->z_mode = inode->i_mode;248}249 250static int zonefs_io_error_cb(struct blk_zone *zone, unsigned int idx,251			      void *data)252{253	struct blk_zone *z = data;254 255	*z = *zone;256	return 0;257}258 259static void zonefs_handle_io_error(struct inode *inode, struct blk_zone *zone,260				   bool write)261{262	struct zonefs_zone *z = zonefs_inode_zone(inode);263	struct super_block *sb = inode->i_sb;264	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);265	loff_t isize, data_size;266 267	/*268	 * Check the zone condition: if the zone is not "bad" (offline or269	 * read-only), read errors are simply signaled to the IO issuer as long270	 * as there is no inconsistency between the inode size and the amount of271	 * data writen in the zone (data_size).272	 */273	data_size = zonefs_check_zone_condition(sb, z, zone);274	isize = i_size_read(inode);275	if (!(z->z_flags & (ZONEFS_ZONE_READONLY | ZONEFS_ZONE_OFFLINE)) &&276	    !write && isize == data_size)277		return;278 279	/*280	 * At this point, we detected either a bad zone or an inconsistency281	 * between the inode size and the amount of data written in the zone.282	 * For the latter case, the cause may be a write IO error or an external283	 * action on the device. Two error patterns exist:284	 * 1) The inode size is lower than the amount of data in the zone:285	 *    a write operation partially failed and data was writen at the end286	 *    of the file. This can happen in the case of a large direct IO287	 *    needing several BIOs and/or write requests to be processed.288	 * 2) The inode size is larger than the amount of data in the zone:289	 *    this can happen with a deferred write error with the use of the290	 *    device side write cache after getting successful write IO291	 *    completions. Other possibilities are (a) an external corruption,292	 *    e.g. an application reset the zone directly, or (b) the device293	 *    has a serious problem (e.g. firmware bug).294	 *295	 * In all cases, warn about inode size inconsistency and handle the296	 * IO error according to the zone condition and to the mount options.297	 */298	if (isize != data_size)299		zonefs_warn(sb,300			    "inode %lu: invalid size %lld (should be %lld)\n",301			    inode->i_ino, isize, data_size);302 303	/*304	 * First handle bad zones signaled by hardware. The mount options305	 * errors=zone-ro and errors=zone-offline result in changing the306	 * zone condition to read-only and offline respectively, as if the307	 * condition was signaled by the hardware.308	 */309	if ((z->z_flags & ZONEFS_ZONE_OFFLINE) ||310	    (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZOL)) {311		zonefs_warn(sb, "inode %lu: read/write access disabled\n",312			    inode->i_ino);313		if (!(z->z_flags & ZONEFS_ZONE_OFFLINE))314			z->z_flags |= ZONEFS_ZONE_OFFLINE;315		zonefs_inode_update_mode(inode);316		data_size = 0;317	} else if ((z->z_flags & ZONEFS_ZONE_READONLY) ||318		   (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_ZRO)) {319		zonefs_warn(sb, "inode %lu: write access disabled\n",320			    inode->i_ino);321		if (!(z->z_flags & ZONEFS_ZONE_READONLY))322			z->z_flags |= ZONEFS_ZONE_READONLY;323		zonefs_inode_update_mode(inode);324		data_size = isize;325	} else if (sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO &&326		   data_size > isize) {327		/* Do not expose garbage data */328		data_size = isize;329	}330 331	/*332	 * If the filesystem is mounted with the explicit-open mount option, we333	 * need to clear the ZONEFS_ZONE_OPEN flag if the zone transitioned to334	 * the read-only or offline condition, to avoid attempting an explicit335	 * close of the zone when the inode file is closed.336	 */337	if ((sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) &&338	    (z->z_flags & (ZONEFS_ZONE_READONLY | ZONEFS_ZONE_OFFLINE)))339		z->z_flags &= ~ZONEFS_ZONE_OPEN;340 341	/*342	 * If error=remount-ro was specified, any error result in remounting343	 * the volume as read-only.344	 */345	if ((sbi->s_mount_opts & ZONEFS_MNTOPT_ERRORS_RO) && !sb_rdonly(sb)) {346		zonefs_warn(sb, "remounting filesystem read-only\n");347		sb->s_flags |= SB_RDONLY;348	}349 350	/*351	 * Update block usage stats and the inode size  to prevent access to352	 * invalid data.353	 */354	zonefs_update_stats(inode, data_size);355	zonefs_i_size_write(inode, data_size);356	z->z_wpoffset = data_size;357	zonefs_inode_account_active(inode);358}359 360/*361 * When an file IO error occurs, check the file zone to see if there is a change362 * in the zone condition (e.g. offline or read-only). For a failed write to a363 * sequential zone, the zone write pointer position must also be checked to364 * eventually correct the file size and zonefs inode write pointer offset365 * (which can be out of sync with the drive due to partial write failures).366 */367void __zonefs_io_error(struct inode *inode, bool write)368{369	struct zonefs_zone *z = zonefs_inode_zone(inode);370	struct super_block *sb = inode->i_sb;371	unsigned int noio_flag;372	struct blk_zone zone;373	int ret;374 375	/*376	 * Conventional zone have no write pointer and cannot become read-only377	 * or offline. So simply fake a report for a single or aggregated zone378	 * and let zonefs_handle_io_error() correct the zone inode information379	 * according to the mount options.380	 */381	if (!zonefs_zone_is_seq(z)) {382		zone.start = z->z_sector;383		zone.len = z->z_size >> SECTOR_SHIFT;384		zone.wp = zone.start + zone.len;385		zone.type = BLK_ZONE_TYPE_CONVENTIONAL;386		zone.cond = BLK_ZONE_COND_NOT_WP;387		zone.capacity = zone.len;388		goto handle_io_error;389	}390 391	/*392	 * Memory allocations in blkdev_report_zones() can trigger a memory393	 * reclaim which may in turn cause a recursion into zonefs as well as394	 * struct request allocations for the same device. The former case may395	 * end up in a deadlock on the inode truncate mutex, while the latter396	 * may prevent IO forward progress. Executing the report zones under397	 * the GFP_NOIO context avoids both problems.398	 */399	noio_flag = memalloc_noio_save();400	ret = blkdev_report_zones(sb->s_bdev, z->z_sector, 1,401				  zonefs_io_error_cb, &zone);402	memalloc_noio_restore(noio_flag);403 404	if (ret != 1) {405		zonefs_err(sb, "Get inode %lu zone information failed %d\n",406			   inode->i_ino, ret);407		zonefs_warn(sb, "remounting filesystem read-only\n");408		sb->s_flags |= SB_RDONLY;409		return;410	}411 412handle_io_error:413	zonefs_handle_io_error(inode, &zone, write);414}415 416static struct kmem_cache *zonefs_inode_cachep;417 418static struct inode *zonefs_alloc_inode(struct super_block *sb)419{420	struct zonefs_inode_info *zi;421 422	zi = alloc_inode_sb(sb, zonefs_inode_cachep, GFP_KERNEL);423	if (!zi)424		return NULL;425 426	inode_init_once(&zi->i_vnode);427	mutex_init(&zi->i_truncate_mutex);428	zi->i_wr_refcnt = 0;429 430	return &zi->i_vnode;431}432 433static void zonefs_free_inode(struct inode *inode)434{435	kmem_cache_free(zonefs_inode_cachep, ZONEFS_I(inode));436}437 438/*439 * File system stat.440 */441static int zonefs_statfs(struct dentry *dentry, struct kstatfs *buf)442{443	struct super_block *sb = dentry->d_sb;444	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);445	enum zonefs_ztype t;446 447	buf->f_type = ZONEFS_MAGIC;448	buf->f_bsize = sb->s_blocksize;449	buf->f_namelen = ZONEFS_NAME_MAX;450 451	spin_lock(&sbi->s_lock);452 453	buf->f_blocks = sbi->s_blocks;454	if (WARN_ON(sbi->s_used_blocks > sbi->s_blocks))455		buf->f_bfree = 0;456	else457		buf->f_bfree = buf->f_blocks - sbi->s_used_blocks;458	buf->f_bavail = buf->f_bfree;459 460	for (t = 0; t < ZONEFS_ZTYPE_MAX; t++) {461		if (sbi->s_zgroup[t].g_nr_zones)462			buf->f_files += sbi->s_zgroup[t].g_nr_zones + 1;463	}464	buf->f_ffree = 0;465 466	spin_unlock(&sbi->s_lock);467 468	buf->f_fsid = uuid_to_fsid(sbi->s_uuid.b);469 470	return 0;471}472 473enum {474	Opt_errors, Opt_explicit_open,475};476 477struct zonefs_context {478	unsigned long s_mount_opts;479};480 481static const struct constant_table zonefs_param_errors[] = {482	{"remount-ro",		ZONEFS_MNTOPT_ERRORS_RO},483	{"zone-ro",		ZONEFS_MNTOPT_ERRORS_ZRO},484	{"zone-offline",	ZONEFS_MNTOPT_ERRORS_ZOL},485	{"repair", 		ZONEFS_MNTOPT_ERRORS_REPAIR},486	{}487};488 489static const struct fs_parameter_spec zonefs_param_spec[] = {490	fsparam_enum	("errors",		Opt_errors, zonefs_param_errors),491	fsparam_flag	("explicit-open",	Opt_explicit_open),492	{}493};494 495static int zonefs_parse_param(struct fs_context *fc, struct fs_parameter *param)496{497	struct zonefs_context *ctx = fc->fs_private;498	struct fs_parse_result result;499	int opt;500 501	opt = fs_parse(fc, zonefs_param_spec, param, &result);502	if (opt < 0)503		return opt;504 505	switch (opt) {506	case Opt_errors:507		ctx->s_mount_opts &= ~ZONEFS_MNTOPT_ERRORS_MASK;508		ctx->s_mount_opts |= result.uint_32;509		break;510	case Opt_explicit_open:511		ctx->s_mount_opts |= ZONEFS_MNTOPT_EXPLICIT_OPEN;512		break;513	default:514		return -EINVAL;515	}516 517	return 0;518}519 520static 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 536static int zonefs_inode_setattr(struct mnt_idmap *idmap,537				struct dentry *dentry, struct iattr *iattr)538{539	struct inode *inode = d_inode(dentry);540	int ret;541 542	if (unlikely(IS_IMMUTABLE(inode)))543		return -EPERM;544 545	ret = setattr_prepare(&nop_mnt_idmap, dentry, iattr);546	if (ret)547		return ret;548 549	/*550	 * Since files and directories cannot be created nor deleted, do not551	 * allow setting any write attributes on the sub-directories grouping552	 * files by zone type.553	 */554	if ((iattr->ia_valid & ATTR_MODE) && S_ISDIR(inode->i_mode) &&555	    (iattr->ia_mode & 0222))556		return -EPERM;557 558	if (((iattr->ia_valid & ATTR_UID) &&559	     !uid_eq(iattr->ia_uid, inode->i_uid)) ||560	    ((iattr->ia_valid & ATTR_GID) &&561	     !gid_eq(iattr->ia_gid, inode->i_gid))) {562		ret = dquot_transfer(&nop_mnt_idmap, inode, iattr);563		if (ret)564			return ret;565	}566 567	if (iattr->ia_valid & ATTR_SIZE) {568		ret = zonefs_file_truncate(inode, iattr->ia_size);569		if (ret)570			return ret;571	}572 573	setattr_copy(&nop_mnt_idmap, inode, iattr);574 575	if (S_ISREG(inode->i_mode)) {576		struct zonefs_zone *z = zonefs_inode_zone(inode);577 578		z->z_mode = inode->i_mode;579		z->z_uid = inode->i_uid;580		z->z_gid = inode->i_gid;581	}582 583	return 0;584}585 586static const struct inode_operations zonefs_file_inode_operations = {587	.setattr	= zonefs_inode_setattr,588};589 590static long zonefs_fname_to_fno(const struct qstr *fname)591{592	const char *name = fname->name;593	unsigned int len = fname->len;594	long fno = 0, shift = 1;595	const char *rname;596	char c = *name;597	unsigned int i;598 599	/*600	 * File names are always a base-10 number string without any601	 * leading 0s.602	 */603	if (!isdigit(c))604		return -ENOENT;605 606	if (len > 1 && c == '0')607		return -ENOENT;608 609	if (len == 1)610		return c - '0';611 612	for (i = 0, rname = name + len - 1; i < len; i++, rname--) {613		c = *rname;614		if (!isdigit(c))615			return -ENOENT;616		fno += (c - '0') * shift;617		shift *= 10;618	}619 620	return fno;621}622 623static struct inode *zonefs_get_file_inode(struct inode *dir,624					   struct dentry *dentry)625{626	struct zonefs_zone_group *zgroup = dir->i_private;627	struct super_block *sb = dir->i_sb;628	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);629	struct zonefs_zone *z;630	struct inode *inode;631	ino_t ino;632	long fno;633 634	/* Get the file number from the file name */635	fno = zonefs_fname_to_fno(&dentry->d_name);636	if (fno < 0)637		return ERR_PTR(fno);638 639	if (!zgroup->g_nr_zones || fno >= zgroup->g_nr_zones)640		return ERR_PTR(-ENOENT);641 642	z = &zgroup->g_zones[fno];643	ino = z->z_sector >> sbi->s_zone_sectors_shift;644	inode = iget_locked(sb, ino);645	if (!inode)646		return ERR_PTR(-ENOMEM);647	if (!(inode->i_state & I_NEW)) {648		WARN_ON_ONCE(inode->i_private != z);649		return inode;650	}651 652	inode->i_ino = ino;653	inode->i_mode = z->z_mode;654	inode_set_mtime_to_ts(inode,655			      inode_set_atime_to_ts(inode, inode_set_ctime_to_ts(inode, inode_get_ctime(dir))));656	inode->i_uid = z->z_uid;657	inode->i_gid = z->z_gid;658	inode->i_size = z->z_wpoffset;659	inode->i_blocks = z->z_capacity >> SECTOR_SHIFT;660	inode->i_private = z;661 662	inode->i_op = &zonefs_file_inode_operations;663	inode->i_fop = &zonefs_file_operations;664	inode->i_mapping->a_ops = &zonefs_file_aops;665	mapping_set_large_folios(inode->i_mapping);666 667	/* Update the inode access rights depending on the zone condition */668	zonefs_inode_update_mode(inode);669 670	unlock_new_inode(inode);671 672	return inode;673}674 675static struct inode *zonefs_get_zgroup_inode(struct super_block *sb,676					     enum zonefs_ztype ztype)677{678	struct inode *root = d_inode(sb->s_root);679	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);680	struct inode *inode;681	ino_t ino = bdev_nr_zones(sb->s_bdev) + ztype + 1;682 683	inode = iget_locked(sb, ino);684	if (!inode)685		return ERR_PTR(-ENOMEM);686	if (!(inode->i_state & I_NEW))687		return inode;688 689	inode->i_ino = ino;690	inode_init_owner(&nop_mnt_idmap, inode, root, S_IFDIR | 0555);691	inode->i_size = sbi->s_zgroup[ztype].g_nr_zones;692	inode_set_mtime_to_ts(inode,693			      inode_set_atime_to_ts(inode, inode_set_ctime_to_ts(inode, inode_get_ctime(root))));694	inode->i_private = &sbi->s_zgroup[ztype];695	set_nlink(inode, 2);696 697	inode->i_op = &zonefs_dir_inode_operations;698	inode->i_fop = &zonefs_dir_operations;699 700	unlock_new_inode(inode);701 702	return inode;703}704 705 706static struct inode *zonefs_get_dir_inode(struct inode *dir,707					  struct dentry *dentry)708{709	struct super_block *sb = dir->i_sb;710	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);711	const char *name = dentry->d_name.name;712	enum zonefs_ztype ztype;713 714	/*715	 * We only need to check for the "seq" directory and716	 * the "cnv" directory if we have conventional zones.717	 */718	if (dentry->d_name.len != 3)719		return ERR_PTR(-ENOENT);720 721	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {722		if (sbi->s_zgroup[ztype].g_nr_zones &&723		    memcmp(name, zonefs_zgroup_name(ztype), 3) == 0)724			break;725	}726	if (ztype == ZONEFS_ZTYPE_MAX)727		return ERR_PTR(-ENOENT);728 729	return zonefs_get_zgroup_inode(sb, ztype);730}731 732static struct dentry *zonefs_lookup(struct inode *dir, struct dentry *dentry,733				    unsigned int flags)734{735	struct inode *inode;736 737	if (dentry->d_name.len > ZONEFS_NAME_MAX)738		return ERR_PTR(-ENAMETOOLONG);739 740	if (dir == d_inode(dir->i_sb->s_root))741		inode = zonefs_get_dir_inode(dir, dentry);742	else743		inode = zonefs_get_file_inode(dir, dentry);744 745	return d_splice_alias(inode, dentry);746}747 748static int zonefs_readdir_root(struct file *file, struct dir_context *ctx)749{750	struct inode *inode = file_inode(file);751	struct super_block *sb = inode->i_sb;752	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);753	enum zonefs_ztype ztype = ZONEFS_ZTYPE_CNV;754	ino_t base_ino = bdev_nr_zones(sb->s_bdev) + 1;755 756	if (ctx->pos >= inode->i_size)757		return 0;758 759	if (!dir_emit_dots(file, ctx))760		return 0;761 762	if (ctx->pos == 2) {763		if (!sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones)764			ztype = ZONEFS_ZTYPE_SEQ;765 766		if (!dir_emit(ctx, zonefs_zgroup_name(ztype), 3,767			      base_ino + ztype, DT_DIR))768			return 0;769		ctx->pos++;770	}771 772	if (ctx->pos == 3 && ztype != ZONEFS_ZTYPE_SEQ) {773		ztype = ZONEFS_ZTYPE_SEQ;774		if (!dir_emit(ctx, zonefs_zgroup_name(ztype), 3,775			      base_ino + ztype, DT_DIR))776			return 0;777		ctx->pos++;778	}779 780	return 0;781}782 783static int zonefs_readdir_zgroup(struct file *file,784				 struct dir_context *ctx)785{786	struct inode *inode = file_inode(file);787	struct zonefs_zone_group *zgroup = inode->i_private;788	struct super_block *sb = inode->i_sb;789	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);790	struct zonefs_zone *z;791	int fname_len;792	char *fname;793	ino_t ino;794	int f;795 796	/*797	 * The size of zone group directories is equal to the number798	 * of zone files in the group and does note include the "." and799	 * ".." entries. Hence the "+ 2" here.800	 */801	if (ctx->pos >= inode->i_size + 2)802		return 0;803 804	if (!dir_emit_dots(file, ctx))805		return 0;806 807	fname = kmalloc(ZONEFS_NAME_MAX, GFP_KERNEL);808	if (!fname)809		return -ENOMEM;810 811	for (f = ctx->pos - 2; f < zgroup->g_nr_zones; f++) {812		z = &zgroup->g_zones[f];813		ino = z->z_sector >> sbi->s_zone_sectors_shift;814		fname_len = snprintf(fname, ZONEFS_NAME_MAX - 1, "%u", f);815		if (!dir_emit(ctx, fname, fname_len, ino, DT_REG))816			break;817		ctx->pos++;818	}819 820	kfree(fname);821 822	return 0;823}824 825static int zonefs_readdir(struct file *file, struct dir_context *ctx)826{827	struct inode *inode = file_inode(file);828 829	if (inode == d_inode(inode->i_sb->s_root))830		return zonefs_readdir_root(file, ctx);831 832	return zonefs_readdir_zgroup(file, ctx);833}834 835const struct inode_operations zonefs_dir_inode_operations = {836	.lookup		= zonefs_lookup,837	.setattr	= zonefs_inode_setattr,838};839 840const struct file_operations zonefs_dir_operations = {841	.llseek		= generic_file_llseek,842	.read		= generic_read_dir,843	.iterate_shared	= zonefs_readdir,844};845 846struct zonefs_zone_data {847	struct super_block	*sb;848	unsigned int		nr_zones[ZONEFS_ZTYPE_MAX];849	sector_t		cnv_zone_start;850	struct blk_zone		*zones;851};852 853static int zonefs_get_zone_info_cb(struct blk_zone *zone, unsigned int idx,854				   void *data)855{856	struct zonefs_zone_data *zd = data;857	struct super_block *sb = zd->sb;858	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);859 860	/*861	 * We do not care about the first zone: it contains the super block862	 * and not exposed as a file.863	 */864	if (!idx)865		return 0;866 867	/*868	 * Count the number of zones that will be exposed as files.869	 * For sequential zones, we always have as many files as zones.870	 * FOr conventional zones, the number of files depends on if we have871	 * conventional zones aggregation enabled.872	 */873	switch (zone->type) {874	case BLK_ZONE_TYPE_CONVENTIONAL:875		if (sbi->s_features & ZONEFS_F_AGGRCNV) {876			/* One file per set of contiguous conventional zones */877			if (!(sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones) ||878			    zone->start != zd->cnv_zone_start)879				sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones++;880			zd->cnv_zone_start = zone->start + zone->len;881		} else {882			/* One file per zone */883			sbi->s_zgroup[ZONEFS_ZTYPE_CNV].g_nr_zones++;884		}885		break;886	case BLK_ZONE_TYPE_SEQWRITE_REQ:887	case BLK_ZONE_TYPE_SEQWRITE_PREF:888		sbi->s_zgroup[ZONEFS_ZTYPE_SEQ].g_nr_zones++;889		break;890	default:891		zonefs_err(zd->sb, "Unsupported zone type 0x%x\n",892			   zone->type);893		return -EIO;894	}895 896	memcpy(&zd->zones[idx], zone, sizeof(struct blk_zone));897 898	return 0;899}900 901static int zonefs_get_zone_info(struct zonefs_zone_data *zd)902{903	struct block_device *bdev = zd->sb->s_bdev;904	int ret;905 906	zd->zones = kvcalloc(bdev_nr_zones(bdev), sizeof(struct blk_zone),907			     GFP_KERNEL);908	if (!zd->zones)909		return -ENOMEM;910 911	/* Get zones information from the device */912	ret = blkdev_report_zones(bdev, 0, BLK_ALL_ZONES,913				  zonefs_get_zone_info_cb, zd);914	if (ret < 0) {915		zonefs_err(zd->sb, "Zone report failed %d\n", ret);916		return ret;917	}918 919	if (ret != bdev_nr_zones(bdev)) {920		zonefs_err(zd->sb, "Invalid zone report (%d/%u zones)\n",921			   ret, bdev_nr_zones(bdev));922		return -EIO;923	}924 925	return 0;926}927 928static inline void zonefs_free_zone_info(struct zonefs_zone_data *zd)929{930	kvfree(zd->zones);931}932 933/*934 * Create a zone group and populate it with zone files.935 */936static int zonefs_init_zgroup(struct super_block *sb,937			      struct zonefs_zone_data *zd,938			      enum zonefs_ztype ztype)939{940	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);941	struct zonefs_zone_group *zgroup = &sbi->s_zgroup[ztype];942	struct blk_zone *zone, *next, *end;943	struct zonefs_zone *z;944	unsigned int n = 0;945	int ret;946 947	/* Allocate the zone group. If it is empty, we have nothing to do. */948	if (!zgroup->g_nr_zones)949		return 0;950 951	zgroup->g_zones = kvcalloc(zgroup->g_nr_zones,952				   sizeof(struct zonefs_zone), GFP_KERNEL);953	if (!zgroup->g_zones)954		return -ENOMEM;955 956	/*957	 * Initialize the zone groups using the device zone information.958	 * We always skip the first zone as it contains the super block959	 * and is not use to back a file.960	 */961	end = zd->zones + bdev_nr_zones(sb->s_bdev);962	for (zone = &zd->zones[1]; zone < end; zone = next) {963 964		next = zone + 1;965		if (zonefs_zone_type(zone) != ztype)966			continue;967 968		if (WARN_ON_ONCE(n >= zgroup->g_nr_zones))969			return -EINVAL;970 971		/*972		 * For conventional zones, contiguous zones can be aggregated973		 * together to form larger files. Note that this overwrites the974		 * length of the first zone of the set of contiguous zones975		 * aggregated together. If one offline or read-only zone is976		 * found, assume that all zones aggregated have the same977		 * condition.978		 */979		if (ztype == ZONEFS_ZTYPE_CNV &&980		    (sbi->s_features & ZONEFS_F_AGGRCNV)) {981			for (; next < end; next++) {982				if (zonefs_zone_type(next) != ztype)983					break;984				zone->len += next->len;985				zone->capacity += next->capacity;986				if (next->cond == BLK_ZONE_COND_READONLY &&987				    zone->cond != BLK_ZONE_COND_OFFLINE)988					zone->cond = BLK_ZONE_COND_READONLY;989				else if (next->cond == BLK_ZONE_COND_OFFLINE)990					zone->cond = BLK_ZONE_COND_OFFLINE;991			}992		}993 994		z = &zgroup->g_zones[n];995		if (ztype == ZONEFS_ZTYPE_CNV)996			z->z_flags |= ZONEFS_ZONE_CNV;997		z->z_sector = zone->start;998		z->z_size = zone->len << SECTOR_SHIFT;999		if (z->z_size > bdev_zone_sectors(sb->s_bdev) << SECTOR_SHIFT &&1000		    !(sbi->s_features & ZONEFS_F_AGGRCNV)) {1001			zonefs_err(sb,1002				"Invalid zone size %llu (device zone sectors %llu)\n",1003				z->z_size,1004				bdev_zone_sectors(sb->s_bdev) << SECTOR_SHIFT);1005			return -EINVAL;1006		}1007 1008		z->z_capacity = min_t(loff_t, MAX_LFS_FILESIZE,1009				      zone->capacity << SECTOR_SHIFT);1010		z->z_wpoffset = zonefs_check_zone_condition(sb, z, zone);1011 1012		z->z_mode = S_IFREG | sbi->s_perm;1013		z->z_uid = sbi->s_uid;1014		z->z_gid = sbi->s_gid;1015 1016		/*1017		 * Let zonefs_inode_update_mode() know that we will need1018		 * special initialization of the inode mode the first time1019		 * it is accessed.1020		 */1021		z->z_flags |= ZONEFS_ZONE_INIT_MODE;1022 1023		sb->s_maxbytes = max(z->z_capacity, sb->s_maxbytes);1024		sbi->s_blocks += z->z_capacity >> sb->s_blocksize_bits;1025		sbi->s_used_blocks += z->z_wpoffset >> sb->s_blocksize_bits;1026 1027		/*1028		 * For sequential zones, make sure that any open zone is closed1029		 * first to ensure that the initial number of open zones is 0,1030		 * in sync with the open zone accounting done when the mount1031		 * option ZONEFS_MNTOPT_EXPLICIT_OPEN is used.1032		 */1033		if (ztype == ZONEFS_ZTYPE_SEQ &&1034		    (zone->cond == BLK_ZONE_COND_IMP_OPEN ||1035		     zone->cond == BLK_ZONE_COND_EXP_OPEN)) {1036			ret = zonefs_zone_mgmt(sb, z, REQ_OP_ZONE_CLOSE);1037			if (ret)1038				return ret;1039		}1040 1041		zonefs_account_active(sb, z);1042 1043		n++;1044	}1045 1046	if (WARN_ON_ONCE(n != zgroup->g_nr_zones))1047		return -EINVAL;1048 1049	zonefs_info(sb, "Zone group \"%s\" has %u file%s\n",1050		    zonefs_zgroup_name(ztype),1051		    zgroup->g_nr_zones,1052		    str_plural(zgroup->g_nr_zones));1053 1054	return 0;1055}1056 1057static void zonefs_free_zgroups(struct super_block *sb)1058{1059	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);1060	enum zonefs_ztype ztype;1061 1062	if (!sbi)1063		return;1064 1065	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {1066		kvfree(sbi->s_zgroup[ztype].g_zones);1067		sbi->s_zgroup[ztype].g_zones = NULL;1068	}1069}1070 1071/*1072 * Create a zone group and populate it with zone files.1073 */1074static int zonefs_init_zgroups(struct super_block *sb)1075{1076	struct zonefs_zone_data zd;1077	enum zonefs_ztype ztype;1078	int ret;1079 1080	/* First get the device zone information */1081	memset(&zd, 0, sizeof(struct zonefs_zone_data));1082	zd.sb = sb;1083	ret = zonefs_get_zone_info(&zd);1084	if (ret)1085		goto cleanup;1086 1087	/* Allocate and initialize the zone groups */1088	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {1089		ret = zonefs_init_zgroup(sb, &zd, ztype);1090		if (ret) {1091			zonefs_info(sb,1092				    "Zone group \"%s\" initialization failed\n",1093				    zonefs_zgroup_name(ztype));1094			break;1095		}1096	}1097 1098cleanup:1099	zonefs_free_zone_info(&zd);1100	if (ret)1101		zonefs_free_zgroups(sb);1102 1103	return ret;1104}1105 1106/*1107 * Read super block information from the device.1108 */1109static int zonefs_read_super(struct super_block *sb)1110{1111	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);1112	struct zonefs_super *super;1113	u32 crc, stored_crc;1114	struct page *page;1115	struct bio_vec bio_vec;1116	struct bio bio;1117	int ret;1118 1119	page = alloc_page(GFP_KERNEL);1120	if (!page)1121		return -ENOMEM;1122 1123	bio_init(&bio, sb->s_bdev, &bio_vec, 1, REQ_OP_READ);1124	bio.bi_iter.bi_sector = 0;1125	__bio_add_page(&bio, page, PAGE_SIZE, 0);1126 1127	ret = submit_bio_wait(&bio);1128	if (ret)1129		goto free_page;1130 1131	super = page_address(page);1132 1133	ret = -EINVAL;1134	if (le32_to_cpu(super->s_magic) != ZONEFS_MAGIC)1135		goto free_page;1136 1137	stored_crc = le32_to_cpu(super->s_crc);1138	super->s_crc = 0;1139	crc = crc32(~0U, (unsigned char *)super, sizeof(struct zonefs_super));1140	if (crc != stored_crc) {1141		zonefs_err(sb, "Invalid checksum (Expected 0x%08x, got 0x%08x)",1142			   crc, stored_crc);1143		goto free_page;1144	}1145 1146	sbi->s_features = le64_to_cpu(super->s_features);1147	if (sbi->s_features & ~ZONEFS_F_DEFINED_FEATURES) {1148		zonefs_err(sb, "Unknown features set 0x%llx\n",1149			   sbi->s_features);1150		goto free_page;1151	}1152 1153	if (sbi->s_features & ZONEFS_F_UID) {1154		sbi->s_uid = make_kuid(current_user_ns(),1155				       le32_to_cpu(super->s_uid));1156		if (!uid_valid(sbi->s_uid)) {1157			zonefs_err(sb, "Invalid UID feature\n");1158			goto free_page;1159		}1160	}1161 1162	if (sbi->s_features & ZONEFS_F_GID) {1163		sbi->s_gid = make_kgid(current_user_ns(),1164				       le32_to_cpu(super->s_gid));1165		if (!gid_valid(sbi->s_gid)) {1166			zonefs_err(sb, "Invalid GID feature\n");1167			goto free_page;1168		}1169	}1170 1171	if (sbi->s_features & ZONEFS_F_PERM)1172		sbi->s_perm = le32_to_cpu(super->s_perm);1173 1174	if (memchr_inv(super->s_reserved, 0, sizeof(super->s_reserved))) {1175		zonefs_err(sb, "Reserved area is being used\n");1176		goto free_page;1177	}1178 1179	import_uuid(&sbi->s_uuid, super->s_uuid);1180	ret = 0;1181 1182free_page:1183	__free_page(page);1184 1185	return ret;1186}1187 1188static const struct super_operations zonefs_sops = {1189	.alloc_inode	= zonefs_alloc_inode,1190	.free_inode	= zonefs_free_inode,1191	.statfs		= zonefs_statfs,1192	.show_options	= zonefs_show_options,1193};1194 1195static int zonefs_get_zgroup_inodes(struct super_block *sb)1196{1197	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);1198	struct inode *dir_inode;1199	enum zonefs_ztype ztype;1200 1201	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {1202		if (!sbi->s_zgroup[ztype].g_nr_zones)1203			continue;1204 1205		dir_inode = zonefs_get_zgroup_inode(sb, ztype);1206		if (IS_ERR(dir_inode))1207			return PTR_ERR(dir_inode);1208 1209		sbi->s_zgroup[ztype].g_inode = dir_inode;1210	}1211 1212	return 0;1213}1214 1215static void zonefs_release_zgroup_inodes(struct super_block *sb)1216{1217	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);1218	enum zonefs_ztype ztype;1219 1220	if (!sbi)1221		return;1222 1223	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {1224		if (sbi->s_zgroup[ztype].g_inode) {1225			iput(sbi->s_zgroup[ztype].g_inode);1226			sbi->s_zgroup[ztype].g_inode = NULL;1227		}1228	}1229}1230 1231/*1232 * Check that the device is zoned. If it is, get the list of zones and create1233 * sub-directories and files according to the device zone configuration and1234 * format options.1235 */1236static int zonefs_fill_super(struct super_block *sb, struct fs_context *fc)1237{1238	struct zonefs_sb_info *sbi;1239	struct zonefs_context *ctx = fc->fs_private;1240	struct inode *inode;1241	enum zonefs_ztype ztype;1242	int ret;1243 1244	if (!bdev_is_zoned(sb->s_bdev)) {1245		zonefs_err(sb, "Not a zoned block device\n");1246		return -EINVAL;1247	}1248 1249	/*1250	 * Initialize super block information: the maximum file size is updated1251	 * when the zone files are created so that the format option1252	 * ZONEFS_F_AGGRCNV which increases the maximum file size of a file1253	 * beyond the zone size is taken into account.1254	 */1255	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);1256	if (!sbi)1257		return -ENOMEM;1258 1259	spin_lock_init(&sbi->s_lock);1260	sb->s_fs_info = sbi;1261	sb->s_magic = ZONEFS_MAGIC;1262	sb->s_maxbytes = 0;1263	sb->s_op = &zonefs_sops;1264	sb->s_time_gran	= 1;1265 1266	/*1267	 * The block size is set to the device zone write granularity to ensure1268	 * that write operations are always aligned according to the device1269	 * interface constraints.1270	 */1271	sb_set_blocksize(sb, bdev_zone_write_granularity(sb->s_bdev));1272	sbi->s_zone_sectors_shift = ilog2(bdev_zone_sectors(sb->s_bdev));1273	sbi->s_uid = GLOBAL_ROOT_UID;1274	sbi->s_gid = GLOBAL_ROOT_GID;1275	sbi->s_perm = 0640;1276	sbi->s_mount_opts = ctx->s_mount_opts;1277 1278	atomic_set(&sbi->s_wro_seq_files, 0);1279	sbi->s_max_wro_seq_files = bdev_max_open_zones(sb->s_bdev);1280	atomic_set(&sbi->s_active_seq_files, 0);1281	sbi->s_max_active_seq_files = bdev_max_active_zones(sb->s_bdev);1282 1283	ret = zonefs_read_super(sb);1284	if (ret)1285		return ret;1286 1287	zonefs_info(sb, "Mounting %u zones", bdev_nr_zones(sb->s_bdev));1288 1289	if (!sbi->s_max_wro_seq_files &&1290	    !sbi->s_max_active_seq_files &&1291	    sbi->s_mount_opts & ZONEFS_MNTOPT_EXPLICIT_OPEN) {1292		zonefs_info(sb,1293			"No open and active zone limits. Ignoring explicit_open mount option\n");1294		sbi->s_mount_opts &= ~ZONEFS_MNTOPT_EXPLICIT_OPEN;1295	}1296 1297	/* Initialize the zone groups */1298	ret = zonefs_init_zgroups(sb);1299	if (ret)1300		goto cleanup;1301 1302	/* Create the root directory inode */1303	ret = -ENOMEM;1304	inode = new_inode(sb);1305	if (!inode)1306		goto cleanup;1307 1308	inode->i_ino = bdev_nr_zones(sb->s_bdev);1309	inode->i_mode = S_IFDIR | 0555;1310	simple_inode_init_ts(inode);1311	inode->i_op = &zonefs_dir_inode_operations;1312	inode->i_fop = &zonefs_dir_operations;1313	inode->i_size = 2;1314	set_nlink(inode, 2);1315	for (ztype = 0; ztype < ZONEFS_ZTYPE_MAX; ztype++) {1316		if (sbi->s_zgroup[ztype].g_nr_zones) {1317			inc_nlink(inode);1318			inode->i_size++;1319		}1320	}1321 1322	sb->s_root = d_make_root(inode);1323	if (!sb->s_root)1324		goto cleanup;1325 1326	/*1327	 * Take a reference on the zone groups directory inodes1328	 * to keep them in the inode cache.1329	 */1330	ret = zonefs_get_zgroup_inodes(sb);1331	if (ret)1332		goto cleanup;1333 1334	ret = zonefs_sysfs_register(sb);1335	if (ret)1336		goto cleanup;1337 1338	return 0;1339 1340cleanup:1341	zonefs_release_zgroup_inodes(sb);1342	zonefs_free_zgroups(sb);1343 1344	return ret;1345}1346 1347static void zonefs_kill_super(struct super_block *sb)1348{1349	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);1350 1351	/* Release the reference on the zone group directory inodes */1352	zonefs_release_zgroup_inodes(sb);1353 1354	kill_block_super(sb);1355 1356	zonefs_sysfs_unregister(sb);1357	zonefs_free_zgroups(sb);1358	kfree(sbi);1359}1360 1361static void zonefs_free_fc(struct fs_context *fc)1362{1363	struct zonefs_context *ctx = fc->fs_private;1364 1365	kfree(ctx);1366}1367 1368static int zonefs_get_tree(struct fs_context *fc)1369{1370	return get_tree_bdev(fc, zonefs_fill_super);1371}1372 1373static int zonefs_reconfigure(struct fs_context *fc)1374{1375	struct zonefs_context *ctx = fc->fs_private;1376	struct super_block *sb = fc->root->d_sb;1377	struct zonefs_sb_info *sbi = sb->s_fs_info;1378 1379	sync_filesystem(fc->root->d_sb);1380	/* Copy new options from ctx into sbi. */1381	sbi->s_mount_opts = ctx->s_mount_opts;1382 1383	return 0;1384}1385 1386static const struct fs_context_operations zonefs_context_ops = {1387	.parse_param    = zonefs_parse_param,1388	.get_tree       = zonefs_get_tree,1389	.reconfigure	= zonefs_reconfigure,1390	.free           = zonefs_free_fc,1391};1392 1393/*1394 * Set up the filesystem mount context.1395 */1396static int zonefs_init_fs_context(struct fs_context *fc)1397{1398	struct zonefs_context *ctx;1399 1400	ctx = kzalloc(sizeof(struct zonefs_context), GFP_KERNEL);1401	if (!ctx)1402		return -ENOMEM;1403	ctx->s_mount_opts = ZONEFS_MNTOPT_ERRORS_RO;1404	fc->ops = &zonefs_context_ops;1405	fc->fs_private = ctx;1406 1407	return 0;1408}1409 1410/*1411 * File system definition and registration.1412 */1413static struct file_system_type zonefs_type = {1414	.owner			= THIS_MODULE,1415	.name			= "zonefs",1416	.kill_sb		= zonefs_kill_super,1417	.fs_flags		= FS_REQUIRES_DEV,1418	.init_fs_context	= zonefs_init_fs_context,1419	.parameters		= zonefs_param_spec,1420};1421 1422static int __init zonefs_init_inodecache(void)1423{1424	zonefs_inode_cachep = kmem_cache_create("zonefs_inode_cache",1425			sizeof(struct zonefs_inode_info), 0,1426			SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,1427			NULL);1428	if (zonefs_inode_cachep == NULL)1429		return -ENOMEM;1430	return 0;1431}1432 1433static void zonefs_destroy_inodecache(void)1434{1435	/*1436	 * Make sure all delayed rcu free inodes are flushed before we1437	 * destroy the inode cache.1438	 */1439	rcu_barrier();1440	kmem_cache_destroy(zonefs_inode_cachep);1441}1442 1443static int __init zonefs_init(void)1444{1445	int ret;1446 1447	BUILD_BUG_ON(sizeof(struct zonefs_super) != ZONEFS_SUPER_SIZE);1448 1449	ret = zonefs_init_inodecache();1450	if (ret)1451		return ret;1452 1453	ret = zonefs_sysfs_init();1454	if (ret)1455		goto destroy_inodecache;1456 1457	ret = register_filesystem(&zonefs_type);1458	if (ret)1459		goto sysfs_exit;1460 1461	return 0;1462 1463sysfs_exit:1464	zonefs_sysfs_exit();1465destroy_inodecache:1466	zonefs_destroy_inodecache();1467 1468	return ret;1469}1470 1471static void __exit zonefs_exit(void)1472{1473	unregister_filesystem(&zonefs_type);1474	zonefs_sysfs_exit();1475	zonefs_destroy_inodecache();1476}1477 1478MODULE_AUTHOR("Damien Le Moal");1479MODULE_DESCRIPTION("Zone file system for zoned block devices");1480MODULE_LICENSE("GPL");1481MODULE_ALIAS_FS("zonefs");1482module_init(zonefs_init);1483module_exit(zonefs_exit);1484