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super.c
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* https://www.huawei.com/
* Copyright (C) 2021, Alibaba Cloud
*/
#include <linux/module.h>
#include <linux/statfs.h>
#include <linux/parser.h>
#include <linux/seq_file.h>
#include <linux/crc32c.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/dax.h>
#include <linux/exportfs.h>
#include "xattr.h"
#define CREATE_TRACE_POINTS
#include <trace/events/erofs.h>
static struct kmem_cache *erofs_inode_cachep __read_mostly;
struct file_system_type erofs_fs_type;
void _erofs_err(struct super_block *sb, const char *function,
const char *fmt, ...)
{
struct va_format vaf;
va_list args;
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
pr_err("(device %s): %s: %pV", sb->s_id, function, &vaf);
va_end(args);
}
void _erofs_info(struct super_block *sb, const char *function,
const char *fmt, ...)
{
struct va_format vaf;
va_list args;
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
pr_info("(device %s): %pV", sb->s_id, &vaf);
va_end(args);
}
static int erofs_superblock_csum_verify(struct super_block *sb, void *sbdata)
{
size_t len = 1 << EROFS_SB(sb)->blkszbits;
struct erofs_super_block *dsb;
u32 expected_crc, crc;
if (len > EROFS_SUPER_OFFSET)
len -= EROFS_SUPER_OFFSET;
dsb = kmemdup(sbdata + EROFS_SUPER_OFFSET, len, GFP_KERNEL);
if (!dsb)
return -ENOMEM;
expected_crc = le32_to_cpu(dsb->checksum);
dsb->checksum = 0;
/* to allow for x86 boot sectors and other oddities. */
crc = crc32c(~0, dsb, len);
kfree(dsb);
if (crc != expected_crc) {
erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected",
crc, expected_crc);
return -EBADMSG;
}
return 0;
}
static void erofs_inode_init_once(void *ptr)
{
struct erofs_inode *vi = ptr;
inode_init_once(&vi->vfs_inode);
}
static struct inode *erofs_alloc_inode(struct super_block *sb)
{
struct erofs_inode *vi =
alloc_inode_sb(sb, erofs_inode_cachep, GFP_KERNEL);
if (!vi)
return NULL;
/* zero out everything except vfs_inode */
memset(vi, 0, offsetof(struct erofs_inode, vfs_inode));
return &vi->vfs_inode;
}
static void erofs_free_inode(struct inode *inode)
{
struct erofs_inode *vi = EROFS_I(inode);
/* be careful of RCU symlink path */
if (inode->i_op == &erofs_fast_symlink_iops)
kfree(inode->i_link);
kfree(vi->xattr_shared_xattrs);
kmem_cache_free(erofs_inode_cachep, vi);
}
static bool check_layout_compatibility(struct super_block *sb,
struct erofs_super_block *dsb)
{
const unsigned int feature = le32_to_cpu(dsb->feature_incompat);
EROFS_SB(sb)->feature_incompat = feature;
/* check if current kernel meets all mandatory requirements */
if (feature & (~EROFS_ALL_FEATURE_INCOMPAT)) {
erofs_err(sb,
"unidentified incompatible feature %x, please upgrade kernel version",
feature & ~EROFS_ALL_FEATURE_INCOMPAT);
return false;
}
return true;
}
/* read variable-sized metadata, offset will be aligned by 4-byte */
void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,
erofs_off_t *offset, int *lengthp)
{
u8 *buffer, *ptr;
int len, i, cnt;
*offset = round_up(*offset, 4);
ptr = erofs_bread(buf, erofs_blknr(sb, *offset), EROFS_KMAP);
if (IS_ERR(ptr))
return ptr;
len = le16_to_cpu(*(__le16 *)&ptr[erofs_blkoff(sb, *offset)]);
if (!len)
len = U16_MAX + 1;
buffer = kmalloc(len, GFP_KERNEL);
if (!buffer)
return ERR_PTR(-ENOMEM);
*offset += sizeof(__le16);
*lengthp = len;
for (i = 0; i < len; i += cnt) {
cnt = min_t(int, sb->s_blocksize - erofs_blkoff(sb, *offset),
len - i);
ptr = erofs_bread(buf, erofs_blknr(sb, *offset), EROFS_KMAP);
if (IS_ERR(ptr)) {
kfree(buffer);
return ptr;
}
memcpy(buffer + i, ptr + erofs_blkoff(sb, *offset), cnt);
*offset += cnt;
}
return buffer;
}
#ifdef CONFIG_EROFS_FS_ZIP
static int erofs_load_compr_cfgs(struct super_block *sb,
struct erofs_super_block *dsb)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
unsigned int algs, alg;
erofs_off_t offset;
int size, ret = 0;
sbi->available_compr_algs = le16_to_cpu(dsb->u1.available_compr_algs);
if (sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS) {
erofs_err(sb, "try to load compressed fs with unsupported algorithms %x",
sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS);
return -EINVAL;
}
erofs_init_metabuf(&buf, sb);
offset = EROFS_SUPER_OFFSET + sbi->sb_size;
alg = 0;
for (algs = sbi->available_compr_algs; algs; algs >>= 1, ++alg) {
void *data;
if (!(algs & 1))
continue;
data = erofs_read_metadata(sb, &buf, &offset, &size);
if (IS_ERR(data)) {
ret = PTR_ERR(data);
break;
}
switch (alg) {
case Z_EROFS_COMPRESSION_LZ4:
ret = z_erofs_load_lz4_config(sb, dsb, data, size);
break;
case Z_EROFS_COMPRESSION_LZMA:
ret = z_erofs_load_lzma_config(sb, dsb, data, size);
break;
case Z_EROFS_COMPRESSION_DEFLATE:
ret = z_erofs_load_deflate_config(sb, dsb, data, size);
break;
default:
DBG_BUGON(1);
ret = -EFAULT;
}
kfree(data);
if (ret)
break;
}
erofs_put_metabuf(&buf);
return ret;
}
#else
static int erofs_load_compr_cfgs(struct super_block *sb,
struct erofs_super_block *dsb)
{
if (dsb->u1.available_compr_algs) {
erofs_err(sb, "try to load compressed fs when compression is disabled");
return -EINVAL;
}
return 0;
}
#endif
static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb,
struct erofs_device_info *dif, erofs_off_t *pos)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
struct erofs_fscache *fscache;
struct erofs_deviceslot *dis;
struct block_device *bdev;
void *ptr;
ptr = erofs_read_metabuf(buf, sb, erofs_blknr(sb, *pos), EROFS_KMAP);
if (IS_ERR(ptr))
return PTR_ERR(ptr);
dis = ptr + erofs_blkoff(sb, *pos);
if (!dif->path) {
if (!dis->tag[0]) {
erofs_err(sb, "empty device tag @ pos %llu", *pos);
return -EINVAL;
}
dif->path = kmemdup_nul(dis->tag, sizeof(dis->tag), GFP_KERNEL);
if (!dif->path)
return -ENOMEM;
}
if (erofs_is_fscache_mode(sb)) {
fscache = erofs_fscache_register_cookie(sb, dif->path, 0);
if (IS_ERR(fscache))
return PTR_ERR(fscache);
dif->fscache = fscache;
} else if (!sbi->devs->flatdev) {
bdev = blkdev_get_by_path(dif->path, BLK_OPEN_READ, sb->s_type,
NULL);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
dif->bdev = bdev;
dif->dax_dev = fs_dax_get_by_bdev(bdev, &dif->dax_part_off,
NULL, NULL);
}
dif->blocks = le32_to_cpu(dis->blocks);
dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr);
sbi->total_blocks += dif->blocks;
*pos += EROFS_DEVT_SLOT_SIZE;
return 0;
}
static int erofs_scan_devices(struct super_block *sb,
struct erofs_super_block *dsb)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
unsigned int ondisk_extradevs;
erofs_off_t pos;
struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
struct erofs_device_info *dif;
int id, err = 0;
sbi->total_blocks = sbi->primarydevice_blocks;
if (!erofs_sb_has_device_table(sbi))
ondisk_extradevs = 0;
else
ondisk_extradevs = le16_to_cpu(dsb->extra_devices);
if (sbi->devs->extra_devices &&
ondisk_extradevs != sbi->devs->extra_devices) {
erofs_err(sb, "extra devices don't match (ondisk %u, given %u)",
ondisk_extradevs, sbi->devs->extra_devices);
return -EINVAL;
}
if (!ondisk_extradevs)
return 0;
if (!sbi->devs->extra_devices && !erofs_is_fscache_mode(sb))
sbi->devs->flatdev = true;
sbi->device_id_mask = roundup_pow_of_two(ondisk_extradevs + 1) - 1;
pos = le16_to_cpu(dsb->devt_slotoff) * EROFS_DEVT_SLOT_SIZE;
down_read(&sbi->devs->rwsem);
if (sbi->devs->extra_devices) {
idr_for_each_entry(&sbi->devs->tree, dif, id) {
err = erofs_init_device(&buf, sb, dif, &pos);
if (err)
break;
}
} else {
for (id = 0; id < ondisk_extradevs; id++) {
dif = kzalloc(sizeof(*dif), GFP_KERNEL);
if (!dif) {
err = -ENOMEM;
break;
}
err = idr_alloc(&sbi->devs->tree, dif, 0, 0, GFP_KERNEL);
if (err < 0) {
kfree(dif);
break;
}
++sbi->devs->extra_devices;
err = erofs_init_device(&buf, sb, dif, &pos);
if (err)
break;
}
}
up_read(&sbi->devs->rwsem);
erofs_put_metabuf(&buf);
return err;
}
static int erofs_read_superblock(struct super_block *sb)
{
struct erofs_sb_info *sbi;
struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
struct erofs_super_block *dsb;
void *data;
int ret;
data = erofs_read_metabuf(&buf, sb, 0, EROFS_KMAP);
if (IS_ERR(data)) {
erofs_err(sb, "cannot read erofs superblock");
return PTR_ERR(data);
}
sbi = EROFS_SB(sb);
dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET);
ret = -EINVAL;
if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) {
erofs_err(sb, "cannot find valid erofs superblock");
goto out;
}
sbi->blkszbits = dsb->blkszbits;
if (sbi->blkszbits < 9 || sbi->blkszbits > PAGE_SHIFT) {
erofs_err(sb, "blkszbits %u isn't supported", sbi->blkszbits);
goto out;
}
if (dsb->dirblkbits) {
erofs_err(sb, "dirblkbits %u isn't supported", dsb->dirblkbits);
goto out;
}
sbi->feature_compat = le32_to_cpu(dsb->feature_compat);
if (erofs_sb_has_sb_chksum(sbi)) {
ret = erofs_superblock_csum_verify(sb, data);
if (ret)
goto out;
}
ret = -EINVAL;
if (!check_layout_compatibility(sb, dsb))
goto out;
sbi->sb_size = 128 + dsb->sb_extslots * EROFS_SB_EXTSLOT_SIZE;
if (sbi->sb_size > PAGE_SIZE - EROFS_SUPER_OFFSET) {
erofs_err(sb, "invalid sb_extslots %u (more than a fs block)",
sbi->sb_size);
goto out;
}
sbi->primarydevice_blocks = le32_to_cpu(dsb->blocks);
sbi->meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr);
#ifdef CONFIG_EROFS_FS_XATTR
sbi->xattr_blkaddr = le32_to_cpu(dsb->xattr_blkaddr);
sbi->xattr_prefix_start = le32_to_cpu(dsb->xattr_prefix_start);
sbi->xattr_prefix_count = dsb->xattr_prefix_count;
#endif
sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact));
sbi->root_nid = le16_to_cpu(dsb->root_nid);
sbi->packed_nid = le64_to_cpu(dsb->packed_nid);
sbi->inos = le64_to_cpu(dsb->inos);
sbi->build_time = le64_to_cpu(dsb->build_time);
sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec);
memcpy(&sb->s_uuid, dsb->uuid, sizeof(dsb->uuid));
ret = strscpy(sbi->volume_name, dsb->volume_name,
sizeof(dsb->volume_name));
if (ret < 0) { /* -E2BIG */
erofs_err(sb, "bad volume name without NIL terminator");
ret = -EFSCORRUPTED;
goto out;
}
/* parse on-disk compression configurations */
if (erofs_sb_has_compr_cfgs(sbi))
ret = erofs_load_compr_cfgs(sb, dsb);
else
ret = z_erofs_load_lz4_config(sb, dsb, NULL, 0);
if (ret < 0)
goto out;
/* handle multiple devices */
ret = erofs_scan_devices(sb, dsb);
if (erofs_is_fscache_mode(sb))
erofs_info(sb, "EXPERIMENTAL fscache-based on-demand read feature in use. Use at your own risk!");
if (erofs_sb_has_fragments(sbi))
erofs_info(sb, "EXPERIMENTAL compressed fragments feature in use. Use at your own risk!");
if (erofs_sb_has_dedupe(sbi))
erofs_info(sb, "EXPERIMENTAL global deduplication feature in use. Use at your own risk!");
out:
erofs_put_metabuf(&buf);
return ret;
}
/* set up default EROFS parameters */
static void erofs_default_options(struct erofs_fs_context *ctx)
{
#ifdef CONFIG_EROFS_FS_ZIP
ctx->opt.cache_strategy = EROFS_ZIP_CACHE_READAROUND;
ctx->opt.max_sync_decompress_pages = 3;
ctx->opt.sync_decompress = EROFS_SYNC_DECOMPRESS_AUTO;
#endif
#ifdef CONFIG_EROFS_FS_XATTR
set_opt(&ctx->opt, XATTR_USER);
#endif
#ifdef CONFIG_EROFS_FS_POSIX_ACL
set_opt(&ctx->opt, POSIX_ACL);
#endif
}
enum {
Opt_user_xattr,
Opt_acl,
Opt_cache_strategy,
Opt_dax,
Opt_dax_enum,
Opt_device,
Opt_fsid,
Opt_domain_id,
Opt_err
};
static const struct constant_table erofs_param_cache_strategy[] = {
{"disabled", EROFS_ZIP_CACHE_DISABLED},
{"readahead", EROFS_ZIP_CACHE_READAHEAD},
{"readaround", EROFS_ZIP_CACHE_READAROUND},
{}
};
static const struct constant_table erofs_dax_param_enums[] = {
{"always", EROFS_MOUNT_DAX_ALWAYS},
{"never", EROFS_MOUNT_DAX_NEVER},
{}
};
static const struct fs_parameter_spec erofs_fs_parameters[] = {
fsparam_flag_no("user_xattr", Opt_user_xattr),
fsparam_flag_no("acl", Opt_acl),
fsparam_enum("cache_strategy", Opt_cache_strategy,
erofs_param_cache_strategy),
fsparam_flag("dax", Opt_dax),
fsparam_enum("dax", Opt_dax_enum, erofs_dax_param_enums),
fsparam_string("device", Opt_device),
fsparam_string("fsid", Opt_fsid),
fsparam_string("domain_id", Opt_domain_id),
{}
};
static bool erofs_fc_set_dax_mode(struct fs_context *fc, unsigned int mode)
{
#ifdef CONFIG_FS_DAX
struct erofs_fs_context *ctx = fc->fs_private;
switch (mode) {
case EROFS_MOUNT_DAX_ALWAYS:
warnfc(fc, "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
set_opt(&ctx->opt, DAX_ALWAYS);
clear_opt(&ctx->opt, DAX_NEVER);
return true;
case EROFS_MOUNT_DAX_NEVER:
set_opt(&ctx->opt, DAX_NEVER);
clear_opt(&ctx->opt, DAX_ALWAYS);
return true;
default:
DBG_BUGON(1);
return false;
}
#else
errorfc(fc, "dax options not supported");
return false;
#endif
}
static int erofs_fc_parse_param(struct fs_context *fc,
struct fs_parameter *param)
{
struct erofs_fs_context *ctx = fc->fs_private;
struct fs_parse_result result;
struct erofs_device_info *dif;
int opt, ret;
opt = fs_parse(fc, erofs_fs_parameters, param, &result);
if (opt < 0)
return opt;
switch (opt) {
case Opt_user_xattr:
#ifdef CONFIG_EROFS_FS_XATTR
if (result.boolean)
set_opt(&ctx->opt, XATTR_USER);
else
clear_opt(&ctx->opt, XATTR_USER);
#else
errorfc(fc, "{,no}user_xattr options not supported");
#endif
break;
case Opt_acl:
#ifdef CONFIG_EROFS_FS_POSIX_ACL
if (result.boolean)
set_opt(&ctx->opt, POSIX_ACL);
else
clear_opt(&ctx->opt, POSIX_ACL);
#else
errorfc(fc, "{,no}acl options not supported");
#endif
break;
case Opt_cache_strategy:
#ifdef CONFIG_EROFS_FS_ZIP
ctx->opt.cache_strategy = result.uint_32;
#else
errorfc(fc, "compression not supported, cache_strategy ignored");
#endif
break;
case Opt_dax:
if (!erofs_fc_set_dax_mode(fc, EROFS_MOUNT_DAX_ALWAYS))
return -EINVAL;
break;
case Opt_dax_enum:
if (!erofs_fc_set_dax_mode(fc, result.uint_32))
return -EINVAL;
break;
case Opt_device:
dif = kzalloc(sizeof(*dif), GFP_KERNEL);
if (!dif)
return -ENOMEM;
dif->path = kstrdup(param->string, GFP_KERNEL);
if (!dif->path) {
kfree(dif);
return -ENOMEM;
}
down_write(&ctx->devs->rwsem);
ret = idr_alloc(&ctx->devs->tree, dif, 0, 0, GFP_KERNEL);
up_write(&ctx->devs->rwsem);
if (ret < 0) {
kfree(dif->path);
kfree(dif);
return ret;
}
++ctx->devs->extra_devices;
break;
#ifdef CONFIG_EROFS_FS_ONDEMAND
case Opt_fsid:
kfree(ctx->fsid);
ctx->fsid = kstrdup(param->string, GFP_KERNEL);
if (!ctx->fsid)
return -ENOMEM;
break;
case Opt_domain_id:
kfree(ctx->domain_id);
ctx->domain_id = kstrdup(param->string, GFP_KERNEL);
if (!ctx->domain_id)
return -ENOMEM;
break;
#else
case Opt_fsid:
case Opt_domain_id:
errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name);
break;
#endif
default:
return -ENOPARAM;
}
return 0;
}
static struct inode *erofs_nfs_get_inode(struct super_block *sb,
u64 ino, u32 generation)
{
return erofs_iget(sb, ino);
}
static struct dentry *erofs_fh_to_dentry(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
erofs_nfs_get_inode);
}
static struct dentry *erofs_fh_to_parent(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
return generic_fh_to_parent(sb, fid, fh_len, fh_type,
erofs_nfs_get_inode);
}
static struct dentry *erofs_get_parent(struct dentry *child)
{
erofs_nid_t nid;
unsigned int d_type;
int err;
err = erofs_namei(d_inode(child), &dotdot_name, &nid, &d_type);
if (err)
return ERR_PTR(err);
return d_obtain_alias(erofs_iget(child->d_sb, nid));
}
static const struct export_operations erofs_export_ops = {
.fh_to_dentry = erofs_fh_to_dentry,
.fh_to_parent = erofs_fh_to_parent,
.get_parent = erofs_get_parent,
};
static int erofs_fc_fill_pseudo_super(struct super_block *sb, struct fs_context *fc)
{
static const struct tree_descr empty_descr = {""};
return simple_fill_super(sb, EROFS_SUPER_MAGIC, &empty_descr);
}
static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct inode *inode;
struct erofs_sb_info *sbi;
struct erofs_fs_context *ctx = fc->fs_private;
int err;
sb->s_magic = EROFS_SUPER_MAGIC;
sb->s_flags |= SB_RDONLY | SB_NOATIME;
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_op = &erofs_sops;
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
sb->s_fs_info = sbi;
sbi->opt = ctx->opt;
sbi->devs = ctx->devs;
ctx->devs = NULL;
sbi->fsid = ctx->fsid;
ctx->fsid = NULL;
sbi->domain_id = ctx->domain_id;
ctx->domain_id = NULL;
sbi->blkszbits = PAGE_SHIFT;
if (erofs_is_fscache_mode(sb)) {
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
err = erofs_fscache_register_fs(sb);
if (err)
return err;
err = super_setup_bdi(sb);
if (err)
return err;
} else {
if (!sb_set_blocksize(sb, PAGE_SIZE)) {
errorfc(fc, "failed to set initial blksize");
return -EINVAL;
}
sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev,
&sbi->dax_part_off,
NULL, NULL);
}
err = erofs_read_superblock(sb);
if (err)
return err;
if (sb->s_blocksize_bits != sbi->blkszbits) {
if (erofs_is_fscache_mode(sb)) {
errorfc(fc, "unsupported blksize for fscache mode");
return -EINVAL;
}
if (!sb_set_blocksize(sb, 1 << sbi->blkszbits)) {
errorfc(fc, "failed to set erofs blksize");
return -EINVAL;
}
}
if (test_opt(&sbi->opt, DAX_ALWAYS)) {
if (!sbi->dax_dev) {
errorfc(fc, "DAX unsupported by block device. Turning off DAX.");
clear_opt(&sbi->opt, DAX_ALWAYS);
} else if (sbi->blkszbits != PAGE_SHIFT) {
errorfc(fc, "unsupported blocksize for DAX");
clear_opt(&sbi->opt, DAX_ALWAYS);
}
}
sb->s_time_gran = 1;
sb->s_xattr = erofs_xattr_handlers;
sb->s_export_op = &erofs_export_ops;
if (test_opt(&sbi->opt, POSIX_ACL))
sb->s_flags |= SB_POSIXACL;
else
sb->s_flags &= ~SB_POSIXACL;
#ifdef CONFIG_EROFS_FS_ZIP
xa_init(&sbi->managed_pslots);
#endif
/* get the root inode */
inode = erofs_iget(sb, ROOT_NID(sbi));
if (IS_ERR(inode))
return PTR_ERR(inode);
if (!S_ISDIR(inode->i_mode)) {
erofs_err(sb, "rootino(nid %llu) is not a directory(i_mode %o)",
ROOT_NID(sbi), inode->i_mode);
iput(inode);
return -EINVAL;
}
sb->s_root = d_make_root(inode);
if (!sb->s_root)
return -ENOMEM;
erofs_shrinker_register(sb);
/* sb->s_umount is already locked, SB_ACTIVE and SB_BORN are not set */
if (erofs_sb_has_fragments(sbi) && sbi->packed_nid) {
sbi->packed_inode = erofs_iget(sb, sbi->packed_nid);
if (IS_ERR(sbi->packed_inode)) {
err = PTR_ERR(sbi->packed_inode);
sbi->packed_inode = NULL;
return err;
}
}
err = erofs_init_managed_cache(sb);
if (err)
return err;
err = erofs_xattr_prefixes_init(sb);
if (err)
return err;
err = erofs_register_sysfs(sb);
if (err)
return err;
erofs_info(sb, "mounted with root inode @ nid %llu.", ROOT_NID(sbi));
return 0;
}
static int erofs_fc_anon_get_tree(struct fs_context *fc)
{
return get_tree_nodev(fc, erofs_fc_fill_pseudo_super);
}
static int erofs_fc_get_tree(struct fs_context *fc)
{
struct erofs_fs_context *ctx = fc->fs_private;
if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && ctx->fsid)
return get_tree_nodev(fc, erofs_fc_fill_super);
return get_tree_bdev(fc, erofs_fc_fill_super);
}
static int erofs_fc_reconfigure(struct fs_context *fc)
{
struct super_block *sb = fc->root->d_sb;
struct erofs_sb_info *sbi = EROFS_SB(sb);
struct erofs_fs_context *ctx = fc->fs_private;
DBG_BUGON(!sb_rdonly(sb));
if (ctx->fsid || ctx->domain_id)
erofs_info(sb, "ignoring reconfiguration for fsid|domain_id.");
if (test_opt(&ctx->opt, POSIX_ACL))
fc->sb_flags |= SB_POSIXACL;
else
fc->sb_flags &= ~SB_POSIXACL;
sbi->opt = ctx->opt;
fc->sb_flags |= SB_RDONLY;
return 0;
}
static int erofs_release_device_info(int id, void *ptr, void *data)
{
struct erofs_device_info *dif = ptr;
fs_put_dax(dif->dax_dev, NULL);
if (dif->bdev)
blkdev_put(dif->bdev, &erofs_fs_type);
erofs_fscache_unregister_cookie(dif->fscache);
dif->fscache = NULL;
kfree(dif->path);
kfree(dif);
return 0;
}
static void erofs_free_dev_context(struct erofs_dev_context *devs)
{
if (!devs)
return;
idr_for_each(&devs->tree, &erofs_release_device_info, NULL);
idr_destroy(&devs->tree);
kfree(devs);
}
static void erofs_fc_free(struct fs_context *fc)
{
struct erofs_fs_context *ctx = fc->fs_private;
erofs_free_dev_context(ctx->devs);
kfree(ctx->fsid);
kfree(ctx->domain_id);
kfree(ctx);
}
static const struct fs_context_operations erofs_context_ops = {
.parse_param = erofs_fc_parse_param,
.get_tree = erofs_fc_get_tree,
.reconfigure = erofs_fc_reconfigure,
.free = erofs_fc_free,
};
static const struct fs_context_operations erofs_anon_context_ops = {
.get_tree = erofs_fc_anon_get_tree,
};
static int erofs_init_fs_context(struct fs_context *fc)
{
struct erofs_fs_context *ctx;
/* pseudo mount for anon inodes */
if (fc->sb_flags & SB_KERNMOUNT) {
fc->ops = &erofs_anon_context_ops;
return 0;
}
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->devs = kzalloc(sizeof(struct erofs_dev_context), GFP_KERNEL);
if (!ctx->devs) {
kfree(ctx);
return -ENOMEM;
}
fc->fs_private = ctx;
idr_init(&ctx->devs->tree);
init_rwsem(&ctx->devs->rwsem);
erofs_default_options(ctx);
fc->ops = &erofs_context_ops;
return 0;
}
/*
* could be triggered after deactivate_locked_super()
* is called, thus including umount and failed to initialize.
*/
static void erofs_kill_sb(struct super_block *sb)
{
struct erofs_sb_info *sbi;
/* pseudo mount for anon inodes */
if (sb->s_flags & SB_KERNMOUNT) {
kill_anon_super(sb);
return;
}
if (erofs_is_fscache_mode(sb))
kill_anon_super(sb);
else
kill_block_super(sb);
sbi = EROFS_SB(sb);
if (!sbi)
return;
erofs_free_dev_context(sbi->devs);
fs_put_dax(sbi->dax_dev, NULL);
erofs_fscache_unregister_fs(sb);
kfree(sbi->fsid);
kfree(sbi->domain_id);
kfree(sbi);
sb->s_fs_info = NULL;
}
/* called when ->s_root is non-NULL */
static void erofs_put_super(struct super_block *sb)
{
struct erofs_sb_info *const sbi = EROFS_SB(sb);
DBG_BUGON(!sbi);
erofs_unregister_sysfs(sb);
erofs_shrinker_unregister(sb);
erofs_xattr_prefixes_cleanup(sb);
#ifdef CONFIG_EROFS_FS_ZIP
iput(sbi->managed_cache);
sbi->managed_cache = NULL;
#endif
iput(sbi->packed_inode);
sbi->packed_inode = NULL;
erofs_free_dev_context(sbi->devs);
sbi->devs = NULL;
erofs_fscache_unregister_fs(sb);
}
struct file_system_type erofs_fs_type = {
.owner = THIS_MODULE,
.name = "erofs",
.init_fs_context = erofs_init_fs_context,
.kill_sb = erofs_kill_sb,
.fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
};
MODULE_ALIAS_FS("erofs");
static int __init erofs_module_init(void)
{
int err;
erofs_check_ondisk_layout_definitions();
erofs_inode_cachep = kmem_cache_create("erofs_inode",
sizeof(struct erofs_inode), 0,
SLAB_RECLAIM_ACCOUNT,
erofs_inode_init_once);
if (!erofs_inode_cachep)
return -ENOMEM;
err = erofs_init_shrinker();
if (err)
goto shrinker_err;
err = z_erofs_lzma_init();
if (err)
goto lzma_err;
err = z_erofs_deflate_init();
if (err)
goto deflate_err;
erofs_pcpubuf_init();
err = z_erofs_init_zip_subsystem();
if (err)
goto zip_err;
err = erofs_init_sysfs();
if (err)
goto sysfs_err;
err = register_filesystem(&erofs_fs_type);
if (err)
goto fs_err;
return 0;
fs_err:
erofs_exit_sysfs();
sysfs_err:
z_erofs_exit_zip_subsystem();
zip_err:
z_erofs_deflate_exit();
deflate_err:
z_erofs_lzma_exit();
lzma_err:
erofs_exit_shrinker();
shrinker_err:
kmem_cache_destroy(erofs_inode_cachep);