drm/panthor: Don't declare a queue blocked if deferred operations are pending

[drm/drm-misc.git] / fs / exfat / super.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
 */

#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/mount.h>
#include <linux/cred.h>
#include <linux/statfs.h>
#include <linux/seq_file.h>
#include <linux/blkdev.h>
#include <linux/fs_struct.h>
#include <linux/iversion.h>
#include <linux/nls.h>
#include <linux/buffer_head.h>
#include <linux/magic.h>

#include "exfat_raw.h"
#include "exfat_fs.h"

static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
static struct kmem_cache *exfat_inode_cachep;

static void exfat_free_iocharset(struct exfat_sb_info *sbi)
{
        if (sbi->options.iocharset != exfat_default_iocharset)
                kfree(sbi->options.iocharset);
}

static void exfat_put_super(struct super_block *sb)
{
        struct exfat_sb_info *sbi = EXFAT_SB(sb);

        mutex_lock(&sbi->s_lock);
        exfat_free_bitmap(sbi);
        brelse(sbi->boot_bh);
        mutex_unlock(&sbi->s_lock);
}

static int exfat_sync_fs(struct super_block *sb, int wait)
{
        struct exfat_sb_info *sbi = EXFAT_SB(sb);
        int err = 0;

        if (unlikely(exfat_forced_shutdown(sb)))
                return 0;

        if (!wait)
                return 0;

        /* If there are some dirty buffers in the bdev inode */
        mutex_lock(&sbi->s_lock);
        sync_blockdev(sb->s_bdev);
        if (exfat_clear_volume_dirty(sb))
                err = -EIO;
        mutex_unlock(&sbi->s_lock);
        return err;
}

static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
{
        struct super_block *sb = dentry->d_sb;
        struct exfat_sb_info *sbi = EXFAT_SB(sb);
        unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);

        if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
                mutex_lock(&sbi->s_lock);
                if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
                        mutex_unlock(&sbi->s_lock);
                        return -EIO;
                }
                mutex_unlock(&sbi->s_lock);
        }

        buf->f_type = sb->s_magic;
        buf->f_bsize = sbi->cluster_size;
        buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
        buf->f_bfree = buf->f_blocks - sbi->used_clusters;
        buf->f_bavail = buf->f_bfree;
        buf->f_fsid = u64_to_fsid(id);
        /* Unicode utf16 255 characters */
        buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
        return 0;
}

static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
{
        struct exfat_sb_info *sbi = EXFAT_SB(sb);
        struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;

        /* retain persistent-flags */
        new_flags |= sbi->vol_flags_persistent;

        /* flags are not changed */
        if (sbi->vol_flags == new_flags)
                return 0;

        sbi->vol_flags = new_flags;

        /* skip updating volume dirty flag,
         * if this volume has been mounted with read-only
         */
        if (sb_rdonly(sb))
                return 0;

        p_boot->vol_flags = cpu_to_le16(new_flags);

        set_buffer_uptodate(sbi->boot_bh);
        mark_buffer_dirty(sbi->boot_bh);

        __sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);

        return 0;
}

int exfat_set_volume_dirty(struct super_block *sb)
{
        struct exfat_sb_info *sbi = EXFAT_SB(sb);

        return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY);
}

int exfat_clear_volume_dirty(struct super_block *sb)
{
        struct exfat_sb_info *sbi = EXFAT_SB(sb);

        return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY);
}

static int exfat_show_options(struct seq_file *m, struct dentry *root)
{
        struct super_block *sb = root->d_sb;
        struct exfat_sb_info *sbi = EXFAT_SB(sb);
        struct exfat_mount_options *opts = &sbi->options;

        /* Show partition info */
        if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
                seq_printf(m, ",uid=%u",
                                from_kuid_munged(&init_user_ns, opts->fs_uid));
        if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
                seq_printf(m, ",gid=%u",
                                from_kgid_munged(&init_user_ns, opts->fs_gid));
        seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
        if (opts->allow_utime)
                seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
        if (opts->utf8)
                seq_puts(m, ",iocharset=utf8");
        else if (sbi->nls_io)
                seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
        if (opts->errors == EXFAT_ERRORS_CONT)
                seq_puts(m, ",errors=continue");
        else if (opts->errors == EXFAT_ERRORS_PANIC)
                seq_puts(m, ",errors=panic");
        else
                seq_puts(m, ",errors=remount-ro");
        if (opts->discard)
                seq_puts(m, ",discard");
        if (opts->keep_last_dots)
                seq_puts(m, ",keep_last_dots");
        if (opts->sys_tz)
                seq_puts(m, ",sys_tz");
        else if (opts->time_offset)
                seq_printf(m, ",time_offset=%d", opts->time_offset);
        if (opts->zero_size_dir)
                seq_puts(m, ",zero_size_dir");
        return 0;
}

int exfat_force_shutdown(struct super_block *sb, u32 flags)
{
        int ret;
        struct exfat_sb_info *sbi = sb->s_fs_info;
        struct exfat_mount_options *opts = &sbi->options;

        if (exfat_forced_shutdown(sb))
                return 0;

        switch (flags) {
        case EXFAT_GOING_DOWN_DEFAULT:
        case EXFAT_GOING_DOWN_FULLSYNC:
                ret = bdev_freeze(sb->s_bdev);
                if (ret)
                        return ret;
                bdev_thaw(sb->s_bdev);
                set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags);
                break;
        case EXFAT_GOING_DOWN_NOSYNC:
                set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags);
                break;
        default:
                return -EINVAL;
        }

        if (opts->discard)
                opts->discard = 0;
        return 0;
}

static void exfat_shutdown(struct super_block *sb)
{
        exfat_force_shutdown(sb, EXFAT_GOING_DOWN_NOSYNC);
}

static struct inode *exfat_alloc_inode(struct super_block *sb)
{
        struct exfat_inode_info *ei;

        ei = alloc_inode_sb(sb, exfat_inode_cachep, GFP_NOFS);
        if (!ei)
                return NULL;

        init_rwsem(&ei->truncate_lock);
        return &ei->vfs_inode;
}

static void exfat_free_inode(struct inode *inode)
{
        kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
}

static const struct super_operations exfat_sops = {
        .alloc_inode    = exfat_alloc_inode,
        .free_inode     = exfat_free_inode,
        .write_inode    = exfat_write_inode,
        .evict_inode    = exfat_evict_inode,
        .put_super      = exfat_put_super,
        .sync_fs        = exfat_sync_fs,
        .statfs         = exfat_statfs,
        .show_options   = exfat_show_options,
        .shutdown       = exfat_shutdown,
};

enum {
        Opt_uid,
        Opt_gid,
        Opt_umask,
        Opt_dmask,
        Opt_fmask,
        Opt_allow_utime,
        Opt_charset,
        Opt_errors,
        Opt_discard,
        Opt_keep_last_dots,
        Opt_sys_tz,
        Opt_time_offset,
        Opt_zero_size_dir,

        /* Deprecated options */
        Opt_utf8,
        Opt_debug,
        Opt_namecase,
        Opt_codepage,
};

static const struct constant_table exfat_param_enums[] = {
        { "continue",           EXFAT_ERRORS_CONT },
        { "panic",              EXFAT_ERRORS_PANIC },
        { "remount-ro",         EXFAT_ERRORS_RO },
        {}
};

static const struct fs_parameter_spec exfat_parameters[] = {
        fsparam_uid("uid",                      Opt_uid),
        fsparam_gid("gid",                      Opt_gid),
        fsparam_u32oct("umask",                 Opt_umask),
        fsparam_u32oct("dmask",                 Opt_dmask),
        fsparam_u32oct("fmask",                 Opt_fmask),
        fsparam_u32oct("allow_utime",           Opt_allow_utime),
        fsparam_string("iocharset",             Opt_charset),
        fsparam_enum("errors",                  Opt_errors, exfat_param_enums),
        fsparam_flag("discard",                 Opt_discard),
        fsparam_flag("keep_last_dots",          Opt_keep_last_dots),
        fsparam_flag("sys_tz",                  Opt_sys_tz),
        fsparam_s32("time_offset",              Opt_time_offset),
        fsparam_flag("zero_size_dir",           Opt_zero_size_dir),
        __fsparam(NULL, "utf8",                 Opt_utf8, fs_param_deprecated,
                  NULL),
        __fsparam(NULL, "debug",                Opt_debug, fs_param_deprecated,
                  NULL),
        __fsparam(fs_param_is_u32, "namecase",  Opt_namecase,
                  fs_param_deprecated, NULL),
        __fsparam(fs_param_is_u32, "codepage",  Opt_codepage,
                  fs_param_deprecated, NULL),
        {}
};

static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
        struct exfat_sb_info *sbi = fc->s_fs_info;
        struct exfat_mount_options *opts = &sbi->options;
        struct fs_parse_result result;
        int opt;

        opt = fs_parse(fc, exfat_parameters, param, &result);
        if (opt < 0)
                return opt;

        switch (opt) {
        case Opt_uid:
                opts->fs_uid = result.uid;
                break;
        case Opt_gid:
                opts->fs_gid = result.gid;
                break;
        case Opt_umask:
                opts->fs_fmask = result.uint_32;
                opts->fs_dmask = result.uint_32;
                break;
        case Opt_dmask:
                opts->fs_dmask = result.uint_32;
                break;
        case Opt_fmask:
                opts->fs_fmask = result.uint_32;
                break;
        case Opt_allow_utime:
                opts->allow_utime = result.uint_32 & 0022;
                break;
        case Opt_charset:
                exfat_free_iocharset(sbi);
                opts->iocharset = param->string;
                param->string = NULL;
                break;
        case Opt_errors:
                opts->errors = result.uint_32;
                break;
        case Opt_discard:
                opts->discard = 1;
                break;
        case Opt_keep_last_dots:
                opts->keep_last_dots = 1;
                break;
        case Opt_sys_tz:
                opts->sys_tz = 1;
                break;
        case Opt_time_offset:
                /*
                 * Make the limit 24 just in case someone invents something
                 * unusual.
                 */
                if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
                        return -EINVAL;
                opts->time_offset = result.int_32;
                break;
        case Opt_zero_size_dir:
                opts->zero_size_dir = true;
                break;
        case Opt_utf8:
        case Opt_debug:
        case Opt_namecase:
        case Opt_codepage:
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static void exfat_hash_init(struct super_block *sb)
{
        struct exfat_sb_info *sbi = EXFAT_SB(sb);
        int i;

        spin_lock_init(&sbi->inode_hash_lock);
        for (i = 0; i < EXFAT_HASH_SIZE; i++)
                INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
}

static int exfat_read_root(struct inode *inode)
{
        struct super_block *sb = inode->i_sb;
        struct exfat_sb_info *sbi = EXFAT_SB(sb);
        struct exfat_inode_info *ei = EXFAT_I(inode);
        struct exfat_chain cdir;
        int num_subdirs, num_clu = 0;

        exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
        ei->entry = -1;
        ei->start_clu = sbi->root_dir;
        ei->flags = ALLOC_FAT_CHAIN;
        ei->type = TYPE_DIR;
        ei->version = 0;
        ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
        ei->hint_stat.eidx = 0;
        ei->hint_stat.clu = sbi->root_dir;
        ei->hint_femp.eidx = EXFAT_HINT_NONE;

        exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
        if (exfat_count_num_clusters(sb, &cdir, &num_clu))
                return -EIO;
        i_size_write(inode, num_clu << sbi->cluster_size_bits);

        num_subdirs = exfat_count_dir_entries(sb, &cdir);
        if (num_subdirs < 0)
                return -EIO;
        set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);

        inode->i_uid = sbi->options.fs_uid;
        inode->i_gid = sbi->options.fs_gid;
        inode_inc_iversion(inode);
        inode->i_generation = 0;
        inode->i_mode = exfat_make_mode(sbi, EXFAT_ATTR_SUBDIR, 0777);
        inode->i_op = &exfat_dir_inode_operations;
        inode->i_fop = &exfat_dir_operations;

        inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
        ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;

        exfat_save_attr(inode, EXFAT_ATTR_SUBDIR);
        ei->i_crtime = simple_inode_init_ts(inode);
        exfat_truncate_inode_atime(inode);
        return 0;
}

static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)
{
        struct exfat_sb_info *sbi = EXFAT_SB(sb);

        if (!is_power_of_2(logical_sect)) {
                exfat_err(sb, "bogus logical sector size %u", logical_sect);
                return -EIO;
        }

        if (logical_sect < sb->s_blocksize) {
                exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",
                          logical_sect);
                return -EIO;
        }

        if (logical_sect > sb->s_blocksize) {
                brelse(sbi->boot_bh);
                sbi->boot_bh = NULL;

                if (!sb_set_blocksize(sb, logical_sect)) {
                        exfat_err(sb, "unable to set blocksize %u",
                                  logical_sect);
                        return -EIO;
                }
                sbi->boot_bh = sb_bread(sb, 0);
                if (!sbi->boot_bh) {
                        exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
                                  sb->s_blocksize);
                        return -EIO;
                }
        }
        return 0;
}

static int exfat_read_boot_sector(struct super_block *sb)
{
        struct boot_sector *p_boot;
        struct exfat_sb_info *sbi = EXFAT_SB(sb);

        /* set block size to read super block */
        sb_min_blocksize(sb, 512);

        /* read boot sector */
        sbi->boot_bh = sb_bread(sb, 0);
        if (!sbi->boot_bh) {
                exfat_err(sb, "unable to read boot sector");
                return -EIO;
        }
        p_boot = (struct boot_sector *)sbi->boot_bh->b_data;

        /* check the validity of BOOT */
        if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {
                exfat_err(sb, "invalid boot record signature");
                return -EINVAL;
        }

        if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) {
                exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */
                return -EINVAL;
        }

        /*
         * must_be_zero field must be filled with zero to prevent mounting
         * from FAT volume.
         */
        if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))
                return -EINVAL;

        if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {
                exfat_err(sb, "bogus number of FAT structure");
                return -EINVAL;
        }

        /*
         * sect_size_bits could be at least 9 and at most 12.
         */
        if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS ||
            p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) {
                exfat_err(sb, "bogus sector size bits : %u",
                                p_boot->sect_size_bits);
                return -EINVAL;
        }

        /*
         * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits.
         */
        if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) {
                exfat_err(sb, "bogus sectors bits per cluster : %u",
                                p_boot->sect_per_clus_bits);
                return -EINVAL;
        }

        sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
        sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;
        sbi->cluster_size_bits = p_boot->sect_per_clus_bits +
                p_boot->sect_size_bits;
        sbi->cluster_size = 1 << sbi->cluster_size_bits;
        sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
        sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);
        sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);
        if (p_boot->num_fats == 2)
                sbi->FAT2_start_sector += sbi->num_FAT_sectors;
        sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
        sbi->num_sectors = le64_to_cpu(p_boot->vol_length);
        /* because the cluster index starts with 2 */
        sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +
                EXFAT_RESERVED_CLUSTERS;

        sbi->root_dir = le32_to_cpu(p_boot->root_cluster);
        sbi->dentries_per_clu = 1 <<
                (sbi->cluster_size_bits - DENTRY_SIZE_BITS);

        sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);
        sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);
        sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
        sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;

        /* check consistencies */
        if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits <
            (u64)sbi->num_clusters * 4) {
                exfat_err(sb, "bogus fat length");
                return -EINVAL;
        }

        if (sbi->data_start_sector <
            (u64)sbi->FAT1_start_sector +
            (u64)sbi->num_FAT_sectors * p_boot->num_fats) {
                exfat_err(sb, "bogus data start sector");
                return -EINVAL;
        }

        if (sbi->vol_flags & VOLUME_DIRTY)
                exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
        if (sbi->vol_flags & MEDIA_FAILURE)
                exfat_warn(sb, "Medium has reported failures. Some data may be lost.");

        /* exFAT file size is limited by a disk volume size */
        sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
                sbi->cluster_size_bits;

        /* check logical sector size */
        if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
                return -EIO;

        return 0;
}

static int exfat_verify_boot_region(struct super_block *sb)
{
        struct buffer_head *bh = NULL;
        u32 chksum = 0;
        __le32 *p_sig, *p_chksum;
        int sn, i;

        /* read boot sector sub-regions */
        for (sn = 0; sn < 11; sn++) {
                bh = sb_bread(sb, sn);
                if (!bh)
                        return -EIO;

                if (sn != 0 && sn <= 8) {
                        /* extended boot sector sub-regions */
                        p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4];
                        if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)
                                exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",
                                           sn, le32_to_cpu(*p_sig));
                }

                chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
                        chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
                brelse(bh);
        }

        /* boot checksum sub-regions */
        bh = sb_bread(sb, sn);
        if (!bh)
                return -EIO;

        for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
                p_chksum = (__le32 *)&bh->b_data[i];
                if (le32_to_cpu(*p_chksum) != chksum) {
                        exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",
                                  le32_to_cpu(*p_chksum), chksum);
                        brelse(bh);
                        return -EINVAL;
                }
        }
        brelse(bh);
        return 0;
}

/* mount the file system volume */
static int __exfat_fill_super(struct super_block *sb)
{
        int ret;
        struct exfat_sb_info *sbi = EXFAT_SB(sb);

        ret = exfat_read_boot_sector(sb);
        if (ret) {
                exfat_err(sb, "failed to read boot sector");
                goto free_bh;
        }

        ret = exfat_verify_boot_region(sb);
        if (ret) {
                exfat_err(sb, "invalid boot region");
                goto free_bh;
        }

        ret = exfat_create_upcase_table(sb);
        if (ret) {
                exfat_err(sb, "failed to load upcase table");
                goto free_bh;
        }

        ret = exfat_load_bitmap(sb);
        if (ret) {
                exfat_err(sb, "failed to load alloc-bitmap");
                goto free_bh;
        }

        ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
        if (ret) {
                exfat_err(sb, "failed to scan clusters");
                goto free_alloc_bitmap;
        }

        return 0;

free_alloc_bitmap:
        exfat_free_bitmap(sbi);
free_bh:
        brelse(sbi->boot_bh);
        return ret;
}

static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
{
        struct exfat_sb_info *sbi = sb->s_fs_info;
        struct exfat_mount_options *opts = &sbi->options;
        struct inode *root_inode;
        int err;

        if (opts->allow_utime == (unsigned short)-1)
                opts->allow_utime = ~opts->fs_dmask & 0022;

        if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) {
                exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard");
                opts->discard = 0;
        }

        sb->s_flags |= SB_NODIRATIME;
        sb->s_magic = EXFAT_SUPER_MAGIC;
        sb->s_op = &exfat_sops;

        sb->s_time_gran = 10 * NSEC_PER_MSEC;
        sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
        sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;

        err = __exfat_fill_super(sb);
        if (err) {
                exfat_err(sb, "failed to recognize exfat type");
                goto check_nls_io;
        }

        /* set up enough so that it can read an inode */
        exfat_hash_init(sb);

        if (!strcmp(sbi->options.iocharset, "utf8"))
                opts->utf8 = 1;
        else {
                sbi->nls_io = load_nls(sbi->options.iocharset);
                if (!sbi->nls_io) {
                        exfat_err(sb, "IO charset %s not found",
                                  sbi->options.iocharset);
                        err = -EINVAL;
                        goto free_table;
                }
        }

        if (sbi->options.utf8)
                sb->s_d_op = &exfat_utf8_dentry_ops;
        else
                sb->s_d_op = &exfat_dentry_ops;

        root_inode = new_inode(sb);
        if (!root_inode) {
                exfat_err(sb, "failed to allocate root inode");
                err = -ENOMEM;
                goto free_table;
        }

        root_inode->i_ino = EXFAT_ROOT_INO;
        inode_set_iversion(root_inode, 1);
        err = exfat_read_root(root_inode);
        if (err) {
                exfat_err(sb, "failed to initialize root inode");
                goto put_inode;
        }

        exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
        insert_inode_hash(root_inode);

        sb->s_root = d_make_root(root_inode);
        if (!sb->s_root) {
                exfat_err(sb, "failed to get the root dentry");
                err = -ENOMEM;
                goto free_table;
        }

        return 0;

put_inode:
        iput(root_inode);
        sb->s_root = NULL;

free_table:
        exfat_free_bitmap(sbi);
        brelse(sbi->boot_bh);

check_nls_io:
        return err;
}

static int exfat_get_tree(struct fs_context *fc)
{
        return get_tree_bdev(fc, exfat_fill_super);
}

static void exfat_free_sbi(struct exfat_sb_info *sbi)
{
        exfat_free_iocharset(sbi);
        kfree(sbi);
}

static void exfat_free(struct fs_context *fc)
{
        struct exfat_sb_info *sbi = fc->s_fs_info;

        if (sbi)
                exfat_free_sbi(sbi);
}

static int exfat_reconfigure(struct fs_context *fc)
{
        fc->sb_flags |= SB_NODIRATIME;

        /* volume flag will be updated in exfat_sync_fs */
        sync_filesystem(fc->root->d_sb);
        return 0;
}

static const struct fs_context_operations exfat_context_ops = {
        .parse_param    = exfat_parse_param,
        .get_tree       = exfat_get_tree,
        .free           = exfat_free,
        .reconfigure    = exfat_reconfigure,
};

static int exfat_init_fs_context(struct fs_context *fc)
{
        struct exfat_sb_info *sbi;

        sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
        if (!sbi)
                return -ENOMEM;

        mutex_init(&sbi->s_lock);
        mutex_init(&sbi->bitmap_lock);
        ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
                        DEFAULT_RATELIMIT_BURST);

        sbi->options.fs_uid = current_uid();
        sbi->options.fs_gid = current_gid();
        sbi->options.fs_fmask = current->fs->umask;
        sbi->options.fs_dmask = current->fs->umask;
        sbi->options.allow_utime = -1;
        sbi->options.iocharset = exfat_default_iocharset;
        sbi->options.errors = EXFAT_ERRORS_RO;

        fc->s_fs_info = sbi;
        fc->ops = &exfat_context_ops;
        return 0;
}

static void delayed_free(struct rcu_head *p)
{
        struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);

        unload_nls(sbi->nls_io);
        exfat_free_upcase_table(sbi);
        exfat_free_sbi(sbi);
}

static void exfat_kill_sb(struct super_block *sb)
{
        struct exfat_sb_info *sbi = sb->s_fs_info;

        kill_block_super(sb);
        if (sbi)
                call_rcu(&sbi->rcu, delayed_free);
}

static struct file_system_type exfat_fs_type = {
        .owner                  = THIS_MODULE,
        .name                   = "exfat",
        .init_fs_context        = exfat_init_fs_context,
        .parameters             = exfat_parameters,
        .kill_sb                = exfat_kill_sb,
        .fs_flags               = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
};

static void exfat_inode_init_once(void *foo)
{
        struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;

        spin_lock_init(&ei->cache_lru_lock);
        ei->nr_caches = 0;
        ei->cache_valid_id = EXFAT_CACHE_VALID + 1;
        INIT_LIST_HEAD(&ei->cache_lru);
        INIT_HLIST_NODE(&ei->i_hash_fat);
        inode_init_once(&ei->vfs_inode);
}

static int __init init_exfat_fs(void)
{
        int err;

        err = exfat_cache_init();
        if (err)
                return err;

        exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
                        sizeof(struct exfat_inode_info),
                        0, SLAB_RECLAIM_ACCOUNT,
                        exfat_inode_init_once);
        if (!exfat_inode_cachep) {
                err = -ENOMEM;
                goto shutdown_cache;
        }

        err = register_filesystem(&exfat_fs_type);
        if (err)
                goto destroy_cache;

        return 0;

destroy_cache:
        kmem_cache_destroy(exfat_inode_cachep);
shutdown_cache:
        exfat_cache_shutdown();
        return err;
}

static void __exit exit_exfat_fs(void)
{
        /*
         * Make sure all delayed rcu free inodes are flushed before we
         * destroy cache.
         */
        rcu_barrier();
        kmem_cache_destroy(exfat_inode_cachep);
        unregister_filesystem(&exfat_fs_type);
        exfat_cache_shutdown();
}

module_init(init_exfat_fs);
module_exit(exit_exfat_fs);

MODULE_ALIAS_FS("exfat");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("exFAT filesystem support");
MODULE_AUTHOR("Samsung Electronics Co., Ltd.");