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brintos / linux-shallow public Read only

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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.4 */5 6#include <linux/fs_context.h>7#include <linux/fs_parser.h>8#include <linux/module.h>9#include <linux/init.h>10#include <linux/time.h>11#include <linux/mount.h>12#include <linux/cred.h>13#include <linux/statfs.h>14#include <linux/seq_file.h>15#include <linux/blkdev.h>16#include <linux/fs_struct.h>17#include <linux/iversion.h>18#include <linux/nls.h>19#include <linux/buffer_head.h>20#include <linux/magic.h>21 22#include "exfat_raw.h"23#include "exfat_fs.h"24 25static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;26static struct kmem_cache *exfat_inode_cachep;27 28static void exfat_free_iocharset(struct exfat_sb_info *sbi)29{30	if (sbi->options.iocharset != exfat_default_iocharset)31		kfree(sbi->options.iocharset);32}33 34static void exfat_put_super(struct super_block *sb)35{36	struct exfat_sb_info *sbi = EXFAT_SB(sb);37 38	mutex_lock(&sbi->s_lock);39	exfat_free_bitmap(sbi);40	brelse(sbi->boot_bh);41	mutex_unlock(&sbi->s_lock);42}43 44static int exfat_sync_fs(struct super_block *sb, int wait)45{46	struct exfat_sb_info *sbi = EXFAT_SB(sb);47	int err = 0;48 49	if (unlikely(exfat_forced_shutdown(sb)))50		return 0;51 52	if (!wait)53		return 0;54 55	/* If there are some dirty buffers in the bdev inode */56	mutex_lock(&sbi->s_lock);57	sync_blockdev(sb->s_bdev);58	if (exfat_clear_volume_dirty(sb))59		err = -EIO;60	mutex_unlock(&sbi->s_lock);61	return err;62}63 64static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)65{66	struct super_block *sb = dentry->d_sb;67	struct exfat_sb_info *sbi = EXFAT_SB(sb);68	unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);69 70	if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {71		mutex_lock(&sbi->s_lock);72		if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {73			mutex_unlock(&sbi->s_lock);74			return -EIO;75		}76		mutex_unlock(&sbi->s_lock);77	}78 79	buf->f_type = sb->s_magic;80	buf->f_bsize = sbi->cluster_size;81	buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */82	buf->f_bfree = buf->f_blocks - sbi->used_clusters;83	buf->f_bavail = buf->f_bfree;84	buf->f_fsid = u64_to_fsid(id);85	/* Unicode utf16 255 characters */86	buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;87	return 0;88}89 90static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)91{92	struct exfat_sb_info *sbi = EXFAT_SB(sb);93	struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;94 95	/* retain persistent-flags */96	new_flags |= sbi->vol_flags_persistent;97 98	/* flags are not changed */99	if (sbi->vol_flags == new_flags)100		return 0;101 102	sbi->vol_flags = new_flags;103 104	/* skip updating volume dirty flag,105	 * if this volume has been mounted with read-only106	 */107	if (sb_rdonly(sb))108		return 0;109 110	p_boot->vol_flags = cpu_to_le16(new_flags);111 112	set_buffer_uptodate(sbi->boot_bh);113	mark_buffer_dirty(sbi->boot_bh);114 115	__sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);116 117	return 0;118}119 120int exfat_set_volume_dirty(struct super_block *sb)121{122	struct exfat_sb_info *sbi = EXFAT_SB(sb);123 124	return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY);125}126 127int exfat_clear_volume_dirty(struct super_block *sb)128{129	struct exfat_sb_info *sbi = EXFAT_SB(sb);130 131	return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY);132}133 134static int exfat_show_options(struct seq_file *m, struct dentry *root)135{136	struct super_block *sb = root->d_sb;137	struct exfat_sb_info *sbi = EXFAT_SB(sb);138	struct exfat_mount_options *opts = &sbi->options;139 140	/* Show partition info */141	if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))142		seq_printf(m, ",uid=%u",143				from_kuid_munged(&init_user_ns, opts->fs_uid));144	if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))145		seq_printf(m, ",gid=%u",146				from_kgid_munged(&init_user_ns, opts->fs_gid));147	seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);148	if (opts->allow_utime)149		seq_printf(m, ",allow_utime=%04o", opts->allow_utime);150	if (opts->utf8)151		seq_puts(m, ",iocharset=utf8");152	else if (sbi->nls_io)153		seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);154	if (opts->errors == EXFAT_ERRORS_CONT)155		seq_puts(m, ",errors=continue");156	else if (opts->errors == EXFAT_ERRORS_PANIC)157		seq_puts(m, ",errors=panic");158	else159		seq_puts(m, ",errors=remount-ro");160	if (opts->discard)161		seq_puts(m, ",discard");162	if (opts->keep_last_dots)163		seq_puts(m, ",keep_last_dots");164	if (opts->sys_tz)165		seq_puts(m, ",sys_tz");166	else if (opts->time_offset)167		seq_printf(m, ",time_offset=%d", opts->time_offset);168	if (opts->zero_size_dir)169		seq_puts(m, ",zero_size_dir");170	return 0;171}172 173int exfat_force_shutdown(struct super_block *sb, u32 flags)174{175	int ret;176	struct exfat_sb_info *sbi = sb->s_fs_info;177	struct exfat_mount_options *opts = &sbi->options;178 179	if (exfat_forced_shutdown(sb))180		return 0;181 182	switch (flags) {183	case EXFAT_GOING_DOWN_DEFAULT:184	case EXFAT_GOING_DOWN_FULLSYNC:185		ret = bdev_freeze(sb->s_bdev);186		if (ret)187			return ret;188		bdev_thaw(sb->s_bdev);189		set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags);190		break;191	case EXFAT_GOING_DOWN_NOSYNC:192		set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags);193		break;194	default:195		return -EINVAL;196	}197 198	if (opts->discard)199		opts->discard = 0;200	return 0;201}202 203static void exfat_shutdown(struct super_block *sb)204{205	exfat_force_shutdown(sb, EXFAT_GOING_DOWN_NOSYNC);206}207 208static struct inode *exfat_alloc_inode(struct super_block *sb)209{210	struct exfat_inode_info *ei;211 212	ei = alloc_inode_sb(sb, exfat_inode_cachep, GFP_NOFS);213	if (!ei)214		return NULL;215 216	init_rwsem(&ei->truncate_lock);217	return &ei->vfs_inode;218}219 220static void exfat_free_inode(struct inode *inode)221{222	kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));223}224 225static const struct super_operations exfat_sops = {226	.alloc_inode	= exfat_alloc_inode,227	.free_inode	= exfat_free_inode,228	.write_inode	= exfat_write_inode,229	.evict_inode	= exfat_evict_inode,230	.put_super	= exfat_put_super,231	.sync_fs	= exfat_sync_fs,232	.statfs		= exfat_statfs,233	.show_options	= exfat_show_options,234	.shutdown	= exfat_shutdown,235};236 237enum {238	Opt_uid,239	Opt_gid,240	Opt_umask,241	Opt_dmask,242	Opt_fmask,243	Opt_allow_utime,244	Opt_charset,245	Opt_errors,246	Opt_discard,247	Opt_keep_last_dots,248	Opt_sys_tz,249	Opt_time_offset,250	Opt_zero_size_dir,251 252	/* Deprecated options */253	Opt_utf8,254	Opt_debug,255	Opt_namecase,256	Opt_codepage,257};258 259static const struct constant_table exfat_param_enums[] = {260	{ "continue",		EXFAT_ERRORS_CONT },261	{ "panic",		EXFAT_ERRORS_PANIC },262	{ "remount-ro",		EXFAT_ERRORS_RO },263	{}264};265 266static const struct fs_parameter_spec exfat_parameters[] = {267	fsparam_uid("uid",			Opt_uid),268	fsparam_gid("gid",			Opt_gid),269	fsparam_u32oct("umask",			Opt_umask),270	fsparam_u32oct("dmask",			Opt_dmask),271	fsparam_u32oct("fmask",			Opt_fmask),272	fsparam_u32oct("allow_utime",		Opt_allow_utime),273	fsparam_string("iocharset",		Opt_charset),274	fsparam_enum("errors",			Opt_errors, exfat_param_enums),275	fsparam_flag("discard",			Opt_discard),276	fsparam_flag("keep_last_dots",		Opt_keep_last_dots),277	fsparam_flag("sys_tz",			Opt_sys_tz),278	fsparam_s32("time_offset",		Opt_time_offset),279	fsparam_flag("zero_size_dir",		Opt_zero_size_dir),280	__fsparam(NULL, "utf8",			Opt_utf8, fs_param_deprecated,281		  NULL),282	__fsparam(NULL, "debug",		Opt_debug, fs_param_deprecated,283		  NULL),284	__fsparam(fs_param_is_u32, "namecase",	Opt_namecase,285		  fs_param_deprecated, NULL),286	__fsparam(fs_param_is_u32, "codepage",	Opt_codepage,287		  fs_param_deprecated, NULL),288	{}289};290 291static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)292{293	struct exfat_sb_info *sbi = fc->s_fs_info;294	struct exfat_mount_options *opts = &sbi->options;295	struct fs_parse_result result;296	int opt;297 298	opt = fs_parse(fc, exfat_parameters, param, &result);299	if (opt < 0)300		return opt;301 302	switch (opt) {303	case Opt_uid:304		opts->fs_uid = result.uid;305		break;306	case Opt_gid:307		opts->fs_gid = result.gid;308		break;309	case Opt_umask:310		opts->fs_fmask = result.uint_32;311		opts->fs_dmask = result.uint_32;312		break;313	case Opt_dmask:314		opts->fs_dmask = result.uint_32;315		break;316	case Opt_fmask:317		opts->fs_fmask = result.uint_32;318		break;319	case Opt_allow_utime:320		opts->allow_utime = result.uint_32 & 0022;321		break;322	case Opt_charset:323		exfat_free_iocharset(sbi);324		opts->iocharset = param->string;325		param->string = NULL;326		break;327	case Opt_errors:328		opts->errors = result.uint_32;329		break;330	case Opt_discard:331		opts->discard = 1;332		break;333	case Opt_keep_last_dots:334		opts->keep_last_dots = 1;335		break;336	case Opt_sys_tz:337		opts->sys_tz = 1;338		break;339	case Opt_time_offset:340		/*341		 * Make the limit 24 just in case someone invents something342		 * unusual.343		 */344		if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)345			return -EINVAL;346		opts->time_offset = result.int_32;347		break;348	case Opt_zero_size_dir:349		opts->zero_size_dir = true;350		break;351	case Opt_utf8:352	case Opt_debug:353	case Opt_namecase:354	case Opt_codepage:355		break;356	default:357		return -EINVAL;358	}359 360	return 0;361}362 363static void exfat_hash_init(struct super_block *sb)364{365	struct exfat_sb_info *sbi = EXFAT_SB(sb);366	int i;367 368	spin_lock_init(&sbi->inode_hash_lock);369	for (i = 0; i < EXFAT_HASH_SIZE; i++)370		INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);371}372 373static int exfat_read_root(struct inode *inode)374{375	struct super_block *sb = inode->i_sb;376	struct exfat_sb_info *sbi = EXFAT_SB(sb);377	struct exfat_inode_info *ei = EXFAT_I(inode);378	struct exfat_chain cdir;379	int num_subdirs, num_clu = 0;380 381	exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);382	ei->entry = -1;383	ei->start_clu = sbi->root_dir;384	ei->flags = ALLOC_FAT_CHAIN;385	ei->type = TYPE_DIR;386	ei->version = 0;387	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;388	ei->hint_stat.eidx = 0;389	ei->hint_stat.clu = sbi->root_dir;390	ei->hint_femp.eidx = EXFAT_HINT_NONE;391 392	exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);393	if (exfat_count_num_clusters(sb, &cdir, &num_clu))394		return -EIO;395	i_size_write(inode, num_clu << sbi->cluster_size_bits);396 397	num_subdirs = exfat_count_dir_entries(sb, &cdir);398	if (num_subdirs < 0)399		return -EIO;400	set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);401 402	inode->i_uid = sbi->options.fs_uid;403	inode->i_gid = sbi->options.fs_gid;404	inode_inc_iversion(inode);405	inode->i_generation = 0;406	inode->i_mode = exfat_make_mode(sbi, EXFAT_ATTR_SUBDIR, 0777);407	inode->i_op = &exfat_dir_inode_operations;408	inode->i_fop = &exfat_dir_operations;409 410	inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;411	ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;412 413	exfat_save_attr(inode, EXFAT_ATTR_SUBDIR);414	ei->i_crtime = simple_inode_init_ts(inode);415	exfat_truncate_inode_atime(inode);416	return 0;417}418 419static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)420{421	struct exfat_sb_info *sbi = EXFAT_SB(sb);422 423	if (!is_power_of_2(logical_sect)) {424		exfat_err(sb, "bogus logical sector size %u", logical_sect);425		return -EIO;426	}427 428	if (logical_sect < sb->s_blocksize) {429		exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",430			  logical_sect);431		return -EIO;432	}433 434	if (logical_sect > sb->s_blocksize) {435		brelse(sbi->boot_bh);436		sbi->boot_bh = NULL;437 438		if (!sb_set_blocksize(sb, logical_sect)) {439			exfat_err(sb, "unable to set blocksize %u",440				  logical_sect);441			return -EIO;442		}443		sbi->boot_bh = sb_bread(sb, 0);444		if (!sbi->boot_bh) {445			exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",446				  sb->s_blocksize);447			return -EIO;448		}449	}450	return 0;451}452 453static int exfat_read_boot_sector(struct super_block *sb)454{455	struct boot_sector *p_boot;456	struct exfat_sb_info *sbi = EXFAT_SB(sb);457 458	/* set block size to read super block */459	sb_min_blocksize(sb, 512);460 461	/* read boot sector */462	sbi->boot_bh = sb_bread(sb, 0);463	if (!sbi->boot_bh) {464		exfat_err(sb, "unable to read boot sector");465		return -EIO;466	}467	p_boot = (struct boot_sector *)sbi->boot_bh->b_data;468 469	/* check the validity of BOOT */470	if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {471		exfat_err(sb, "invalid boot record signature");472		return -EINVAL;473	}474 475	if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) {476		exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */477		return -EINVAL;478	}479 480	/*481	 * must_be_zero field must be filled with zero to prevent mounting482	 * from FAT volume.483	 */484	if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))485		return -EINVAL;486 487	if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {488		exfat_err(sb, "bogus number of FAT structure");489		return -EINVAL;490	}491 492	/*493	 * sect_size_bits could be at least 9 and at most 12.494	 */495	if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS ||496	    p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) {497		exfat_err(sb, "bogus sector size bits : %u",498				p_boot->sect_size_bits);499		return -EINVAL;500	}501 502	/*503	 * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits.504	 */505	if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) {506		exfat_err(sb, "bogus sectors bits per cluster : %u",507				p_boot->sect_per_clus_bits);508		return -EINVAL;509	}510 511	sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;512	sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;513	sbi->cluster_size_bits = p_boot->sect_per_clus_bits +514		p_boot->sect_size_bits;515	sbi->cluster_size = 1 << sbi->cluster_size_bits;516	sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);517	sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);518	sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);519	if (p_boot->num_fats == 2)520		sbi->FAT2_start_sector += sbi->num_FAT_sectors;521	sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);522	sbi->num_sectors = le64_to_cpu(p_boot->vol_length);523	/* because the cluster index starts with 2 */524	sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +525		EXFAT_RESERVED_CLUSTERS;526 527	sbi->root_dir = le32_to_cpu(p_boot->root_cluster);528	sbi->dentries_per_clu = 1 <<529		(sbi->cluster_size_bits - DENTRY_SIZE_BITS);530 531	sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);532	sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);533	sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;534	sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;535 536	/* check consistencies */537	if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits <538	    (u64)sbi->num_clusters * 4) {539		exfat_err(sb, "bogus fat length");540		return -EINVAL;541	}542 543	if (sbi->data_start_sector <544	    (u64)sbi->FAT1_start_sector +545	    (u64)sbi->num_FAT_sectors * p_boot->num_fats) {546		exfat_err(sb, "bogus data start sector");547		return -EINVAL;548	}549 550	if (sbi->vol_flags & VOLUME_DIRTY)551		exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");552	if (sbi->vol_flags & MEDIA_FAILURE)553		exfat_warn(sb, "Medium has reported failures. Some data may be lost.");554 555	/* exFAT file size is limited by a disk volume size */556	sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<557		sbi->cluster_size_bits;558 559	/* check logical sector size */560	if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))561		return -EIO;562 563	return 0;564}565 566static int exfat_verify_boot_region(struct super_block *sb)567{568	struct buffer_head *bh = NULL;569	u32 chksum = 0;570	__le32 *p_sig, *p_chksum;571	int sn, i;572 573	/* read boot sector sub-regions */574	for (sn = 0; sn < 11; sn++) {575		bh = sb_bread(sb, sn);576		if (!bh)577			return -EIO;578 579		if (sn != 0 && sn <= 8) {580			/* extended boot sector sub-regions */581			p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4];582			if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)583				exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",584					   sn, le32_to_cpu(*p_sig));585		}586 587		chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,588			chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);589		brelse(bh);590	}591 592	/* boot checksum sub-regions */593	bh = sb_bread(sb, sn);594	if (!bh)595		return -EIO;596 597	for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {598		p_chksum = (__le32 *)&bh->b_data[i];599		if (le32_to_cpu(*p_chksum) != chksum) {600			exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",601				  le32_to_cpu(*p_chksum), chksum);602			brelse(bh);603			return -EINVAL;604		}605	}606	brelse(bh);607	return 0;608}609 610/* mount the file system volume */611static int __exfat_fill_super(struct super_block *sb)612{613	int ret;614	struct exfat_sb_info *sbi = EXFAT_SB(sb);615 616	ret = exfat_read_boot_sector(sb);617	if (ret) {618		exfat_err(sb, "failed to read boot sector");619		goto free_bh;620	}621 622	ret = exfat_verify_boot_region(sb);623	if (ret) {624		exfat_err(sb, "invalid boot region");625		goto free_bh;626	}627 628	ret = exfat_create_upcase_table(sb);629	if (ret) {630		exfat_err(sb, "failed to load upcase table");631		goto free_bh;632	}633 634	ret = exfat_load_bitmap(sb);635	if (ret) {636		exfat_err(sb, "failed to load alloc-bitmap");637		goto free_bh;638	}639 640	ret = exfat_count_used_clusters(sb, &sbi->used_clusters);641	if (ret) {642		exfat_err(sb, "failed to scan clusters");643		goto free_alloc_bitmap;644	}645 646	return 0;647 648free_alloc_bitmap:649	exfat_free_bitmap(sbi);650free_bh:651	brelse(sbi->boot_bh);652	return ret;653}654 655static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)656{657	struct exfat_sb_info *sbi = sb->s_fs_info;658	struct exfat_mount_options *opts = &sbi->options;659	struct inode *root_inode;660	int err;661 662	if (opts->allow_utime == (unsigned short)-1)663		opts->allow_utime = ~opts->fs_dmask & 0022;664 665	if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) {666		exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard");667		opts->discard = 0;668	}669 670	sb->s_flags |= SB_NODIRATIME;671	sb->s_magic = EXFAT_SUPER_MAGIC;672	sb->s_op = &exfat_sops;673 674	sb->s_time_gran = 10 * NSEC_PER_MSEC;675	sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;676	sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;677 678	err = __exfat_fill_super(sb);679	if (err) {680		exfat_err(sb, "failed to recognize exfat type");681		goto check_nls_io;682	}683 684	/* set up enough so that it can read an inode */685	exfat_hash_init(sb);686 687	if (!strcmp(sbi->options.iocharset, "utf8"))688		opts->utf8 = 1;689	else {690		sbi->nls_io = load_nls(sbi->options.iocharset);691		if (!sbi->nls_io) {692			exfat_err(sb, "IO charset %s not found",693				  sbi->options.iocharset);694			err = -EINVAL;695			goto free_table;696		}697	}698 699	if (sbi->options.utf8)700		sb->s_d_op = &exfat_utf8_dentry_ops;701	else702		sb->s_d_op = &exfat_dentry_ops;703 704	root_inode = new_inode(sb);705	if (!root_inode) {706		exfat_err(sb, "failed to allocate root inode");707		err = -ENOMEM;708		goto free_table;709	}710 711	root_inode->i_ino = EXFAT_ROOT_INO;712	inode_set_iversion(root_inode, 1);713	err = exfat_read_root(root_inode);714	if (err) {715		exfat_err(sb, "failed to initialize root inode");716		goto put_inode;717	}718 719	exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);720	insert_inode_hash(root_inode);721 722	sb->s_root = d_make_root(root_inode);723	if (!sb->s_root) {724		exfat_err(sb, "failed to get the root dentry");725		err = -ENOMEM;726		goto free_table;727	}728 729	return 0;730 731put_inode:732	iput(root_inode);733	sb->s_root = NULL;734 735free_table:736	exfat_free_bitmap(sbi);737	brelse(sbi->boot_bh);738 739check_nls_io:740	return err;741}742 743static int exfat_get_tree(struct fs_context *fc)744{745	return get_tree_bdev(fc, exfat_fill_super);746}747 748static void exfat_free_sbi(struct exfat_sb_info *sbi)749{750	exfat_free_iocharset(sbi);751	kfree(sbi);752}753 754static void exfat_free(struct fs_context *fc)755{756	struct exfat_sb_info *sbi = fc->s_fs_info;757 758	if (sbi)759		exfat_free_sbi(sbi);760}761 762static int exfat_reconfigure(struct fs_context *fc)763{764	fc->sb_flags |= SB_NODIRATIME;765 766	/* volume flag will be updated in exfat_sync_fs */767	sync_filesystem(fc->root->d_sb);768	return 0;769}770 771static const struct fs_context_operations exfat_context_ops = {772	.parse_param	= exfat_parse_param,773	.get_tree	= exfat_get_tree,774	.free		= exfat_free,775	.reconfigure	= exfat_reconfigure,776};777 778static int exfat_init_fs_context(struct fs_context *fc)779{780	struct exfat_sb_info *sbi;781 782	sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);783	if (!sbi)784		return -ENOMEM;785 786	mutex_init(&sbi->s_lock);787	mutex_init(&sbi->bitmap_lock);788	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,789			DEFAULT_RATELIMIT_BURST);790 791	sbi->options.fs_uid = current_uid();792	sbi->options.fs_gid = current_gid();793	sbi->options.fs_fmask = current->fs->umask;794	sbi->options.fs_dmask = current->fs->umask;795	sbi->options.allow_utime = -1;796	sbi->options.iocharset = exfat_default_iocharset;797	sbi->options.errors = EXFAT_ERRORS_RO;798 799	fc->s_fs_info = sbi;800	fc->ops = &exfat_context_ops;801	return 0;802}803 804static void delayed_free(struct rcu_head *p)805{806	struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);807 808	unload_nls(sbi->nls_io);809	exfat_free_upcase_table(sbi);810	exfat_free_sbi(sbi);811}812 813static void exfat_kill_sb(struct super_block *sb)814{815	struct exfat_sb_info *sbi = sb->s_fs_info;816 817	kill_block_super(sb);818	if (sbi)819		call_rcu(&sbi->rcu, delayed_free);820}821 822static struct file_system_type exfat_fs_type = {823	.owner			= THIS_MODULE,824	.name			= "exfat",825	.init_fs_context	= exfat_init_fs_context,826	.parameters		= exfat_parameters,827	.kill_sb		= exfat_kill_sb,828	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP,829};830 831static void exfat_inode_init_once(void *foo)832{833	struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;834 835	spin_lock_init(&ei->cache_lru_lock);836	ei->nr_caches = 0;837	ei->cache_valid_id = EXFAT_CACHE_VALID + 1;838	INIT_LIST_HEAD(&ei->cache_lru);839	INIT_HLIST_NODE(&ei->i_hash_fat);840	inode_init_once(&ei->vfs_inode);841}842 843static int __init init_exfat_fs(void)844{845	int err;846 847	err = exfat_cache_init();848	if (err)849		return err;850 851	exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",852			sizeof(struct exfat_inode_info),853			0, SLAB_RECLAIM_ACCOUNT,854			exfat_inode_init_once);855	if (!exfat_inode_cachep) {856		err = -ENOMEM;857		goto shutdown_cache;858	}859 860	err = register_filesystem(&exfat_fs_type);861	if (err)862		goto destroy_cache;863 864	return 0;865 866destroy_cache:867	kmem_cache_destroy(exfat_inode_cachep);868shutdown_cache:869	exfat_cache_shutdown();870	return err;871}872 873static void __exit exit_exfat_fs(void)874{875	/*876	 * Make sure all delayed rcu free inodes are flushed before we877	 * destroy cache.878	 */879	rcu_barrier();880	kmem_cache_destroy(exfat_inode_cachep);881	unregister_filesystem(&exfat_fs_type);882	exfat_cache_shutdown();883}884 885module_init(init_exfat_fs);886module_exit(exit_exfat_fs);887 888MODULE_ALIAS_FS("exfat");889MODULE_LICENSE("GPL");890MODULE_DESCRIPTION("exFAT filesystem support");891MODULE_AUTHOR("Samsung Electronics Co., Ltd.");892