exfat: add super block operations
This adds the implementation of superblock operations for exfat.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
new file mode 100644
index 0000000..f06e0b5
--- /dev/null
+++ b/fs/exfat/super.c
@@ -0,0 +1,728 @@
+// 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 "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_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_iocharset(sbi);
+ exfat_free_upcase_table(sbi);
+ kfree(sbi);
+}
+
+static void exfat_put_super(struct super_block *sb)
+{
+ struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+ mutex_lock(&sbi->s_lock);
+ if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state))
+ sync_blockdev(sb->s_bdev);
+ exfat_set_vol_flags(sb, VOL_CLEAN);
+ exfat_free_bitmap(sbi);
+ mutex_unlock(&sbi->s_lock);
+
+ call_rcu(&sbi->rcu, exfat_delayed_free);
+}
+
+static int exfat_sync_fs(struct super_block *sb, int wait)
+{
+ struct exfat_sb_info *sbi = EXFAT_SB(sb);
+ int err = 0;
+
+ /* If there are some dirty buffers in the bdev inode */
+ mutex_lock(&sbi->s_lock);
+ if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state)) {
+ sync_blockdev(sb->s_bdev);
+ if (exfat_set_vol_flags(sb, VOL_CLEAN))
+ 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.val[0] = (unsigned int)id;
+ buf->f_fsid.val[1] = (unsigned int)(id >> 32);
+ /* Unicode utf16 255 characters */
+ buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
+ return 0;
+}
+
+int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flag)
+{
+ struct exfat_sb_info *sbi = EXFAT_SB(sb);
+ struct pbr64 *bpb;
+ bool sync = 0;
+
+ /* flags are not changed */
+ if (sbi->vol_flag == new_flag)
+ return 0;
+
+ sbi->vol_flag = new_flag;
+
+ /* skip updating volume dirty flag,
+ * if this volume has been mounted with read-only
+ */
+ if (sb_rdonly(sb))
+ return 0;
+
+ if (!sbi->pbr_bh) {
+ sbi->pbr_bh = sb_bread(sb, 0);
+ if (!sbi->pbr_bh) {
+ exfat_msg(sb, KERN_ERR, "failed to read boot sector");
+ return -ENOMEM;
+ }
+ }
+
+ bpb = (struct pbr64 *)sbi->pbr_bh->b_data;
+ bpb->bsx.vol_flags = cpu_to_le16(new_flag);
+
+ if (new_flag == VOL_DIRTY && !buffer_dirty(sbi->pbr_bh))
+ sync = true;
+ else
+ sync = false;
+
+ set_buffer_uptodate(sbi->pbr_bh);
+ mark_buffer_dirty(sbi->pbr_bh);
+
+ if (sync)
+ sync_dirty_buffer(sbi->pbr_bh);
+ return 0;
+}
+
+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);
+ seq_printf(m, ",bps=%ld", sb->s_blocksize);
+ 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->time_offset)
+ seq_printf(m, ",time_offset=%d", opts->time_offset);
+ return 0;
+}
+
+static struct inode *exfat_alloc_inode(struct super_block *sb)
+{
+ struct exfat_inode_info *ei;
+
+ ei = kmem_cache_alloc(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,
+};
+
+enum {
+ Opt_uid,
+ Opt_gid,
+ Opt_umask,
+ Opt_dmask,
+ Opt_fmask,
+ Opt_allow_utime,
+ Opt_charset,
+ Opt_errors,
+ Opt_discard,
+ Opt_time_offset,
+};
+
+static const struct fs_parameter_spec exfat_param_specs[] = {
+ fsparam_u32("uid", Opt_uid),
+ fsparam_u32("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),
+ fsparam_flag("discard", Opt_discard),
+ fsparam_s32("time_offset", Opt_time_offset),
+ {}
+};
+
+static const struct fs_parameter_enum exfat_param_enums[] = {
+ { Opt_errors, "continue", EXFAT_ERRORS_CONT },
+ { Opt_errors, "panic", EXFAT_ERRORS_PANIC },
+ { Opt_errors, "remount-ro", EXFAT_ERRORS_RO },
+ {}
+};
+
+static const struct fs_parameter_description exfat_parameters = {
+ .name = "exfat",
+ .specs = exfat_param_specs,
+ .enums = exfat_param_enums,
+};
+
+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 = make_kuid(current_user_ns(), result.uint_32);
+ break;
+ case Opt_gid:
+ opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
+ 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 = kstrdup(param->string, GFP_KERNEL);
+ if (!opts->iocharset)
+ return -ENOMEM;
+ break;
+ case Opt_errors:
+ opts->errors = result.uint_32;
+ break;
+ case Opt_discard:
+ opts->discard = 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;
+ 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->rwoffset = 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, ATTR_SUBDIR, 0777);
+ inode->i_op = &exfat_dir_inode_operations;
+ inode->i_fop = &exfat_dir_operations;
+
+ inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1))
+ & ~(sbi->cluster_size - 1)) >> inode->i_blkbits;
+ EXFAT_I(inode)->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;
+ EXFAT_I(inode)->i_size_aligned = i_size_read(inode);
+ EXFAT_I(inode)->i_size_ondisk = i_size_read(inode);
+
+ exfat_save_attr(inode, ATTR_SUBDIR);
+ inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
+ current_time(inode);
+ exfat_cache_init_inode(inode);
+ return 0;
+}
+
+static struct pbr *exfat_read_pbr_with_logical_sector(struct super_block *sb,
+ struct buffer_head **prev_bh)
+{
+ struct pbr *p_pbr = (struct pbr *) (*prev_bh)->b_data;
+ unsigned short logical_sect = 0;
+
+ logical_sect = 1 << p_pbr->bsx.f64.sect_size_bits;
+
+ if (!is_power_of_2(logical_sect) ||
+ logical_sect < 512 || logical_sect > 4096) {
+ exfat_msg(sb, KERN_ERR, "bogus logical sector size %u",
+ logical_sect);
+ return NULL;
+ }
+
+ if (logical_sect < sb->s_blocksize) {
+ exfat_msg(sb, KERN_ERR,
+ "logical sector size too small for device (logical sector size = %u)",
+ logical_sect);
+ return NULL;
+ }
+
+ if (logical_sect > sb->s_blocksize) {
+ struct buffer_head *bh = NULL;
+
+ __brelse(*prev_bh);
+ *prev_bh = NULL;
+
+ if (!sb_set_blocksize(sb, logical_sect)) {
+ exfat_msg(sb, KERN_ERR,
+ "unable to set blocksize %u", logical_sect);
+ return NULL;
+ }
+ bh = sb_bread(sb, 0);
+ if (!bh) {
+ exfat_msg(sb, KERN_ERR,
+ "unable to read boot sector (logical sector size = %lu)",
+ sb->s_blocksize);
+ return NULL;
+ }
+
+ *prev_bh = bh;
+ p_pbr = (struct pbr *) bh->b_data;
+ }
+ return p_pbr;
+}
+
+/* mount the file system volume */
+static int __exfat_fill_super(struct super_block *sb)
+{
+ int ret;
+ struct pbr *p_pbr;
+ struct pbr64 *p_bpb;
+ struct buffer_head *bh;
+ struct exfat_sb_info *sbi = EXFAT_SB(sb);
+
+ /* set block size to read super block */
+ sb_min_blocksize(sb, 512);
+
+ /* read boot sector */
+ bh = sb_bread(sb, 0);
+ if (!bh) {
+ exfat_msg(sb, KERN_ERR, "unable to read boot sector");
+ return -EIO;
+ }
+
+ /* PRB is read */
+ p_pbr = (struct pbr *)bh->b_data;
+
+ /* check the validity of PBR */
+ if (le16_to_cpu((p_pbr->signature)) != PBR_SIGNATURE) {
+ exfat_msg(sb, KERN_ERR, "invalid boot record signature");
+ ret = -EINVAL;
+ goto free_bh;
+ }
+
+
+ /* check logical sector size */
+ p_pbr = exfat_read_pbr_with_logical_sector(sb, &bh);
+ if (!p_pbr) {
+ ret = -EIO;
+ goto free_bh;
+ }
+
+ /*
+ * res_zero field must be filled with zero to prevent mounting
+ * from FAT volume.
+ */
+ if (memchr_inv(p_pbr->bpb.f64.res_zero, 0,
+ sizeof(p_pbr->bpb.f64.res_zero))) {
+ ret = -EINVAL;
+ goto free_bh;
+ }
+
+ p_bpb = (struct pbr64 *)p_pbr;
+ if (!p_bpb->bsx.num_fats) {
+ exfat_msg(sb, KERN_ERR, "bogus number of FAT structure");
+ ret = -EINVAL;
+ goto free_bh;
+ }
+
+ sbi->sect_per_clus = 1 << p_bpb->bsx.sect_per_clus_bits;
+ sbi->sect_per_clus_bits = p_bpb->bsx.sect_per_clus_bits;
+ sbi->cluster_size_bits = sbi->sect_per_clus_bits + sb->s_blocksize_bits;
+ sbi->cluster_size = 1 << sbi->cluster_size_bits;
+ sbi->num_FAT_sectors = le32_to_cpu(p_bpb->bsx.fat_length);
+ sbi->FAT1_start_sector = le32_to_cpu(p_bpb->bsx.fat_offset);
+ sbi->FAT2_start_sector = p_bpb->bsx.num_fats == 1 ?
+ sbi->FAT1_start_sector :
+ sbi->FAT1_start_sector + sbi->num_FAT_sectors;
+ sbi->data_start_sector = le32_to_cpu(p_bpb->bsx.clu_offset);
+ sbi->num_sectors = le64_to_cpu(p_bpb->bsx.vol_length);
+ /* because the cluster index starts with 2 */
+ sbi->num_clusters = le32_to_cpu(p_bpb->bsx.clu_count) +
+ EXFAT_RESERVED_CLUSTERS;
+
+ sbi->root_dir = le32_to_cpu(p_bpb->bsx.root_cluster);
+ sbi->dentries_per_clu = 1 <<
+ (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
+
+ sbi->vol_flag = le16_to_cpu(p_bpb->bsx.vol_flags);
+ sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
+ sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
+
+ if (le16_to_cpu(p_bpb->bsx.vol_flags) & VOL_DIRTY) {
+ sbi->vol_flag |= VOL_DIRTY;
+ exfat_msg(sb, KERN_WARNING,
+ "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
+ }
+
+ /* exFAT file size is limited by a disk volume size */
+ sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
+ sbi->cluster_size_bits;
+
+ ret = exfat_create_upcase_table(sb);
+ if (ret) {
+ exfat_msg(sb, KERN_ERR, "failed to load upcase table");
+ goto free_bh;
+ }
+
+ ret = exfat_load_bitmap(sb);
+ if (ret) {
+ exfat_msg(sb, KERN_ERR, "failed to load alloc-bitmap");
+ goto free_upcase_table;
+ }
+
+ ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
+ if (ret) {
+ exfat_msg(sb, KERN_ERR, "failed to scan clusters");
+ goto free_alloc_bitmap;
+ }
+
+ return 0;
+
+free_alloc_bitmap:
+ exfat_free_bitmap(sbi);
+free_upcase_table:
+ exfat_free_upcase_table(sbi);
+free_bh:
+ brelse(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) {
+ struct request_queue *q = bdev_get_queue(sb->s_bdev);
+
+ if (!blk_queue_discard(q))
+ exfat_msg(sb, KERN_WARNING,
+ "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 = 1;
+ sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
+ sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
+
+ err = __exfat_fill_super(sb);
+ if (err) {
+ exfat_msg(sb, KERN_ERR, "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_msg(sb, KERN_ERR, "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_msg(sb, KERN_ERR, "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_msg(sb, KERN_ERR, "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_msg(sb, KERN_ERR, "failed to get the root dentry");
+ err = -ENOMEM;
+ goto put_inode;
+ }
+
+ return 0;
+
+put_inode:
+ iput(root_inode);
+ sb->s_root = NULL;
+
+free_table:
+ exfat_free_upcase_table(sbi);
+ exfat_free_bitmap(sbi);
+
+check_nls_io:
+ unload_nls(sbi->nls_io);
+ exfat_free_iocharset(sbi);
+ sb->s_fs_info = NULL;
+ kfree(sbi);
+ return err;
+}
+
+static int exfat_get_tree(struct fs_context *fc)
+{
+ return get_tree_bdev(fc, exfat_fill_super);
+}
+
+static void exfat_free(struct fs_context *fc)
+{
+ kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations exfat_context_ops = {
+ .parse_param = exfat_parse_param,
+ .get_tree = exfat_get_tree,
+ .free = exfat_free,
+};
+
+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);
+ 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 struct file_system_type exfat_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "exfat",
+ .init_fs_context = exfat_init_fs_context,
+ .parameters = &exfat_parameters,
+ .kill_sb = kill_block_super,
+ .fs_flags = FS_REQUIRES_DEV,
+};
+
+static void exfat_inode_init_once(void *foo)
+{
+ struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;
+
+ 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 | SLAB_MEM_SPREAD,
+ 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_LICENSE("GPL");
+MODULE_DESCRIPTION("exFAT filesystem support");
+MODULE_AUTHOR("Samsung Electronics Co., Ltd.");
