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linux/fs/exfat/super.c
Dongliang Cui f761fcdd28 exfat: Implement sops->shutdown and ioctl 
We found that when writing a large file through buffer write, if the
disk is inaccessible, exFAT does not return an error normally, which
leads to the writing process not stopping properly.

To easily reproduce this issue, you can follow the steps below:

1. format a device to exFAT and then mount (with a full disk erase)
2. dd if=/dev/zero of=/exfat_mount/test.img bs=1M count=8192
3. eject the device

You may find that the dd process does not stop immediately and may
continue for a long time.

The root cause of this issue is that during buffer write process,
exFAT does not need to access the disk to look up directory entries
or the FAT table (whereas FAT would do) every time data is written.
Instead, exFAT simply marks the buffer as dirty and returns,
delegating the writeback operation to the writeback process.

If the disk cannot be accessed at this time, the error will only be
returned to the writeback process, and the original process will not
receive the error, so it cannot be returned to the user side.

When the disk cannot be accessed normally, an error should be returned
to stop the writing process.

Implement sops->shutdown and ioctl to shut down the file system
when underlying block device is marked dead.

Signed-off-by: Dongliang Cui <dongliang.cui@unisoc.com>
Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2024-09-18 07:40:56 +09:00

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// 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.");
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