#include <linux/statfs.h>
#include <linux/seq_file.h>
#include <linux/crc32c.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/exportfs.h>
#include <linux/backing-dev.h>
#include <linux/pseudo_fs.h>
#include "xattr.h"
#define CREATE_TRACE_POINTS
#include <trace/events/erofs.h>
static struct kmem_cache *erofs_inode_cachep __read_mostly;
void _erofs_printk(struct super_block *sb, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
int level;
va_start(args, fmt);
level = printk_get_level(fmt);
vaf.fmt = printk_skip_level(fmt);
vaf.va = &args;
if (sb)
printk("%c%cerofs (device %s): %pV",
KERN_SOH_ASCII, level, sb->s_id, &vaf);
else
printk("%c%cerofs: %pV", KERN_SOH_ASCII, level, &vaf);
va_end(args);
}
static int erofs_superblock_csum_verify(struct super_block *sb, void *sbdata)
{
struct erofs_super_block *dsb = sbdata + EROFS_SUPER_OFFSET;
u32 len = 1 << EROFS_SB(sb)->blkszbits, crc;
if (len > EROFS_SUPER_OFFSET)
len -= EROFS_SUPER_OFFSET;
len -= offsetof(struct erofs_super_block, checksum) +
sizeof(dsb->checksum);
crc = crc32c(0x5045B54A, (&dsb->checksum) + 1, len);
if (crc == le32_to_cpu(dsb->checksum))
return 0;
erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected",
crc, le32_to_cpu(dsb->checksum));
return -EBADMSG;
}
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;
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);
if (inode->i_op == &erofs_fast_symlink_iops)
kfree(inode->i_link);
kfree(vi->xattr_shared_xattrs);
kmem_cache_free(erofs_inode_cachep, vi);
}
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, *offset, true);
if (IS_ERR(ptr))
return ptr;
len = le16_to_cpu(*(__le16 *)ptr);
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, *offset, true);
if (IS_ERR(ptr)) {
kfree(buffer);
return ptr;
}
memcpy(buffer + i, ptr, cnt);
*offset += cnt;
}
return buffer;
}
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 file *file;
dis = erofs_read_metabuf(buf, sb, *pos, false);
if (IS_ERR(dis))
return PTR_ERR(dis);
if (!sbi->devs->flatdev && !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) {
file = erofs_is_fileio_mode(sbi) ?
filp_open(dif->path, O_RDONLY | O_LARGEFILE, 0) :
bdev_file_open_by_path(dif->path,
BLK_OPEN_READ, sb->s_type, NULL);
if (IS_ERR(file)) {
if (file == ERR_PTR(-ENOTBLK))
return -EINVAL;
return PTR_ERR(file);
}
if (!erofs_is_fileio_mode(sbi)) {
dif->dax_dev = fs_dax_get_by_bdev(file_bdev(file),
&dif->dax_part_off, NULL, NULL);
} else if (!S_ISREG(file_inode(file)->i_mode)) {
fput(file);
return -EINVAL;
}
if (!dif->dax_dev && test_opt(&sbi->opt, DAX_ALWAYS)) {
erofs_info(sb, "DAX unsupported by %s. Turning off DAX.",
dif->path);
clear_opt(&sbi->opt, DAX_ALWAYS);
}
dif->file = file;
}
dif->blocks = le32_to_cpu(dis->blocks_lo);
dif->uniaddr = le32_to_cpu(dis->uniaddr_lo);
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->dif0.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 (test_opt(&sbi->opt, DAX_ALWAYS) && !sbi->dif0.dax_dev) {
erofs_info(sb, "DAX unsupported by block device. Turning off DAX.");
clear_opt(&sbi->opt, DAX_ALWAYS);
}
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_obj(*dif);
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 = EROFS_SB(sb);
struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
struct erofs_super_block *dsb;
void *data;
int ret;
data = erofs_read_metabuf(&buf, sb, 0, false);
if (IS_ERR(data)) {
erofs_err(sb, "cannot read erofs superblock");
return PTR_ERR(data);
}
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;
sbi->feature_incompat = le32_to_cpu(dsb->feature_incompat);
if (sbi->feature_incompat & ~EROFS_ALL_FEATURE_INCOMPAT) {
erofs_err(sb, "unidentified incompatible feature %x, please upgrade kernel",
sbi->feature_incompat & ~EROFS_ALL_FEATURE_INCOMPAT);
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->dif0.blocks = le32_to_cpu(dsb->blocks_lo);
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;
sbi->xattr_filter_reserved = dsb->xattr_filter_reserved;
if (erofs_sb_has_ishare_xattrs(sbi)) {
if (dsb->ishare_xattr_prefix_id >= sbi->xattr_prefix_count) {
erofs_err(sb, "invalid ishare xattr prefix id %u",
dsb->ishare_xattr_prefix_id);
ret = -EFSCORRUPTED;
goto out;
}
sbi->ishare_xattr_prefix_id = dsb->ishare_xattr_prefix_id;
}
#endif
sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact));
if (erofs_sb_has_48bit(sbi) && dsb->rootnid_8b) {
sbi->root_nid = le64_to_cpu(dsb->rootnid_8b);
sbi->dif0.blocks = sbi->dif0.blocks |
((u64)le16_to_cpu(dsb->rb.blocks_hi) << 32);
} else {
sbi->root_nid = le16_to_cpu(dsb->rb.rootnid_2b);
}
sbi->packed_nid = le64_to_cpu(dsb->packed_nid);
if (erofs_sb_has_metabox(sbi)) {
ret = -EFSCORRUPTED;
if (sbi->sb_size <= offsetof(struct erofs_super_block,
metabox_nid))
goto out;
sbi->metabox_nid = le64_to_cpu(dsb->metabox_nid);
if (sbi->metabox_nid & BIT_ULL(EROFS_DIRENT_NID_METABOX_BIT))
goto out;
}
sbi->inos = le64_to_cpu(dsb->inos);
sbi->epoch = (s64)le64_to_cpu(dsb->epoch);
sbi->fixed_nsec = le32_to_cpu(dsb->fixed_nsec);
super_set_uuid(sb, (void *)dsb->uuid, sizeof(dsb->uuid));
if (dsb->volume_name[0]) {
sbi->volume_name = kstrndup(dsb->volume_name,
sizeof(dsb->volume_name), GFP_KERNEL);
if (!sbi->volume_name) {
ret = -ENOMEM;
goto out;
}
}
if (IS_ENABLED(CONFIG_EROFS_FS_ZIP)) {
ret = z_erofs_parse_cfgs(sb, dsb);
if (ret < 0)
goto out;
} else if (dsb->u1.available_compr_algs ||
erofs_sb_has_lz4_0padding(sbi)) {
erofs_err(sb, "compression disabled, unable to mount compressed EROFS");
ret = -EOPNOTSUPP;
goto out;
}
ret = erofs_scan_devices(sb, dsb);
if (erofs_sb_has_48bit(sbi))
erofs_info(sb, "EXPERIMENTAL 48-bit layout support in use. Use at your own risk!");
if (erofs_sb_has_metabox(sbi))
erofs_info(sb, "EXPERIMENTAL metadata compression support in use. Use at your own risk!");
if (erofs_is_fscache_mode(sb))
erofs_info(sb, "[deprecated] fscache-based on-demand read feature in use. Use at your own risk!");
out:
erofs_put_metabuf(&buf);
return ret;
}
static void erofs_default_options(struct erofs_sb_info *sbi)
{
#ifdef CONFIG_EROFS_FS_ZIP
sbi->opt.cache_strategy = EROFS_ZIP_CACHE_READAROUND;
sbi->sync_decompress = EROFS_SYNC_DECOMPRESS_AUTO;
#endif
if (IS_ENABLED(CONFIG_EROFS_FS_XATTR))
set_opt(&sbi->opt, XATTR_USER);
if (IS_ENABLED(CONFIG_EROFS_FS_POSIX_ACL))
set_opt(&sbi->opt, POSIX_ACL);
}
enum {
Opt_user_xattr, Opt_acl, Opt_cache_strategy, Opt_dax, Opt_dax_enum,
Opt_device, Opt_fsid, Opt_domain_id, Opt_directio, Opt_fsoffset,
Opt_inode_share,
};
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),
fsparam_flag_no("directio", Opt_directio),
fsparam_u64("fsoffset", Opt_fsoffset),
fsparam_flag("inode_share", Opt_inode_share),
{}
};
static bool erofs_fc_set_dax_mode(struct fs_context *fc, unsigned int mode)
{
if (IS_ENABLED(CONFIG_FS_DAX)) {
struct erofs_sb_info *sbi = fc->s_fs_info;
if (mode == EROFS_MOUNT_DAX_ALWAYS) {
set_opt(&sbi->opt, DAX_ALWAYS);
clear_opt(&sbi->opt, DAX_NEVER);
return true;
} else if (mode == EROFS_MOUNT_DAX_NEVER) {
set_opt(&sbi->opt, DAX_NEVER);
clear_opt(&sbi->opt, DAX_ALWAYS);
return true;
}
DBG_BUGON(1);
return false;
}
errorfc(fc, "dax options not supported");
return false;
}
static int erofs_fc_parse_param(struct fs_context *fc,
struct fs_parameter *param)
{
struct erofs_sb_info *sbi = fc->s_fs_info;
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:
if (!IS_ENABLED(CONFIG_EROFS_FS_XATTR))
errorfc(fc, "{,no}user_xattr options not supported");
else if (result.boolean)
set_opt(&sbi->opt, XATTR_USER);
else
clear_opt(&sbi->opt, XATTR_USER);
break;
case Opt_acl:
if (!IS_ENABLED(CONFIG_EROFS_FS_POSIX_ACL))
errorfc(fc, "{,no}acl options not supported");
else if (result.boolean)
set_opt(&sbi->opt, POSIX_ACL);
else
clear_opt(&sbi->opt, POSIX_ACL);
break;
case Opt_cache_strategy:
if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP))
errorfc(fc, "compression not supported, cache_strategy ignored");
else
sbi->opt.cache_strategy = result.uint_32;
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_obj(*dif);
if (!dif)
return -ENOMEM;
dif->path = kstrdup(param->string, GFP_KERNEL);
if (!dif->path) {
kfree(dif);
return -ENOMEM;
}
down_write(&sbi->devs->rwsem);
ret = idr_alloc(&sbi->devs->tree, dif, 0, 0, GFP_KERNEL);
up_write(&sbi->devs->rwsem);
if (ret < 0) {
kfree(dif->path);
kfree(dif);
return ret;
}
++sbi->devs->extra_devices;
break;
#ifdef CONFIG_EROFS_FS_ONDEMAND
case Opt_fsid:
kfree(sbi->fsid);
sbi->fsid = kstrdup(param->string, GFP_KERNEL);
if (!sbi->fsid)
return -ENOMEM;
break;
#endif
#if defined(CONFIG_EROFS_FS_ONDEMAND) || defined(CONFIG_EROFS_FS_PAGE_CACHE_SHARE)
case Opt_domain_id:
kfree_sensitive(sbi->domain_id);
sbi->domain_id = no_free_ptr(param->string);
break;
#else
case Opt_fsid:
case Opt_domain_id:
errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name);
break;
#endif
case Opt_directio:
if (!IS_ENABLED(CONFIG_EROFS_FS_BACKED_BY_FILE))
errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name);
else if (result.boolean)
set_opt(&sbi->opt, DIRECT_IO);
else
clear_opt(&sbi->opt, DIRECT_IO);
break;
case Opt_fsoffset:
sbi->dif0.fsoff = result.uint_64;
break;
case Opt_inode_share:
if (!IS_ENABLED(CONFIG_EROFS_FS_PAGE_CACHE_SHARE))
errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name);
else
set_opt(&sbi->opt, INODE_SHARE);
break;
}
return 0;
}
static int erofs_encode_fh(struct inode *inode, u32 *fh, int *max_len,
struct inode *parent)
{
erofs_nid_t nid = EROFS_I(inode)->nid;
int len = parent ? 6 : 3;
if (*max_len < len) {
*max_len = len;
return FILEID_INVALID;
}
fh[0] = (u32)(nid >> 32);
fh[1] = (u32)(nid & 0xffffffff);
fh[2] = inode->i_generation;
if (parent) {
nid = EROFS_I(parent)->nid;
fh[3] = (u32)(nid >> 32);
fh[4] = (u32)(nid & 0xffffffff);
fh[5] = parent->i_generation;
}
*max_len = len;
return parent ? FILEID_INO64_GEN_PARENT : FILEID_INO64_GEN;
}
static struct dentry *erofs_fh_to_dentry(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
if ((fh_type != FILEID_INO64_GEN &&
fh_type != FILEID_INO64_GEN_PARENT) || fh_len < 3)
return NULL;
return d_obtain_alias(erofs_iget(sb,
((u64)fid->raw[0] << 32) | fid->raw[1]));
}
static struct dentry *erofs_fh_to_parent(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
if (fh_type != FILEID_INO64_GEN_PARENT || fh_len < 6)
return NULL;
return d_obtain_alias(erofs_iget(sb,
((u64)fid->raw[3] << 32) | fid->raw[4]));
}
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 = {
.encode_fh = erofs_encode_fh,
.fh_to_dentry = erofs_fh_to_dentry,
.fh_to_parent = erofs_fh_to_parent,
.get_parent = erofs_get_parent,
};
static void erofs_set_sysfs_name(struct super_block *sb)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
if (sbi->domain_id && sbi->fsid)
super_set_sysfs_name_generic(sb, "%s,%s", sbi->domain_id,
sbi->fsid);
else if (sbi->fsid)
super_set_sysfs_name_generic(sb, "%s", sbi->fsid);
else if (erofs_is_fileio_mode(sbi))
super_set_sysfs_name_generic(sb, "%s",
bdi_dev_name(sb->s_bdi));
else
super_set_sysfs_name_id(sb);
}
static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct inode *inode;
struct erofs_sb_info *sbi = EROFS_SB(sb);
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;
if (!sbi->domain_id && test_opt(&sbi->opt, INODE_SHARE)) {
errorfc(fc, "domain_id is needed when inode_ishare is on");
return -EINVAL;
}
if (test_opt(&sbi->opt, DAX_ALWAYS) && test_opt(&sbi->opt, INODE_SHARE)) {
errorfc(fc, "FSDAX is not allowed when inode_ishare is on");
return -EINVAL;
}
sbi->blkszbits = PAGE_SHIFT;
if (!sb->s_bdev) {
if (erofs_is_fileio_mode(sbi)) {
inode = file_inode(sbi->dif0.file);
if ((inode->i_sb->s_op == &erofs_sops &&
!inode->i_sb->s_bdev) ||
inode->i_sb->s_stack_depth) {
erofs_err(sb, "file-backed mounts cannot be applied to stacked fses");
return -ENOTBLK;
}
}
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
if (erofs_is_fscache_mode(sb)) {
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->dif0.dax_dev = fs_dax_get_by_bdev(sb->s_bdev,
&sbi->dif0.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 (erofs_is_fileio_mode(sbi)) {
sb->s_blocksize = 1 << sbi->blkszbits;
sb->s_blocksize_bits = sbi->blkszbits;
} else if (!sb_set_blocksize(sb, 1 << sbi->blkszbits)) {
errorfc(fc, "failed to set erofs blksize");
return -EINVAL;
}
}
if (sbi->dif0.fsoff) {
if (sbi->dif0.fsoff & (sb->s_blocksize - 1))
return invalfc(fc, "fsoffset %llu is not aligned to block size %lu",
sbi->dif0.fsoff, sb->s_blocksize);
if (erofs_is_fscache_mode(sb))
return invalfc(fc, "cannot use fsoffset in fscache mode");
}
if (test_opt(&sbi->opt, DAX_ALWAYS) && sbi->blkszbits != PAGE_SHIFT) {
erofs_info(sb, "unsupported blocksize for DAX");
clear_opt(&sbi->opt, DAX_ALWAYS);
}
if (test_opt(&sbi->opt, INODE_SHARE) && !erofs_sb_has_ishare_xattrs(sbi)) {
erofs_info(sb, "on-disk ishare xattrs not found. Turning off inode_share.");
clear_opt(&sbi->opt, INODE_SHARE);
}
if (test_opt(&sbi->opt, INODE_SHARE))
erofs_info(sb, "EXPERIMENTAL EROFS page cache share support in use. Use at your own risk!");
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;
err = z_erofs_init_super(sb);
if (err)
return err;
if (erofs_sb_has_fragments(sbi) && sbi->packed_nid) {
inode = erofs_iget(sb, sbi->packed_nid);
if (IS_ERR(inode))
return PTR_ERR(inode);
sbi->packed_inode = inode;
}
if (erofs_sb_has_metabox(sbi)) {
inode = erofs_iget(sb, sbi->metabox_nid);
if (IS_ERR(inode))
return PTR_ERR(inode);
sbi->metabox_inode = inode;
}
inode = erofs_iget(sb, sbi->root_nid);
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)",
sbi->root_nid, inode->i_mode);
iput(inode);
return -EINVAL;
}
sb->s_root = d_make_root(inode);
if (!sb->s_root)
return -ENOMEM;
erofs_shrinker_register(sb);
err = erofs_xattr_prefixes_init(sb);
if (err)
return err;
erofs_set_sysfs_name(sb);
err = erofs_register_sysfs(sb);
if (err)
return err;
sbi->dir_ra_bytes = EROFS_DIR_RA_BYTES;
erofs_info(sb, "mounted with root inode @ nid %llu.", sbi->root_nid);
return 0;
}
static int erofs_fc_get_tree(struct fs_context *fc)
{
struct erofs_sb_info *sbi = fc->s_fs_info;
int ret;
if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && sbi->fsid)
return get_tree_nodev(fc, erofs_fc_fill_super);
ret = get_tree_bdev_flags(fc, erofs_fc_fill_super,
IS_ENABLED(CONFIG_EROFS_FS_BACKED_BY_FILE) ?
GET_TREE_BDEV_QUIET_LOOKUP : 0);
if (IS_ENABLED(CONFIG_EROFS_FS_BACKED_BY_FILE) && ret == -ENOTBLK) {
struct file *file;
if (!fc->source)
return invalf(fc, "No source specified");
file = filp_open(fc->source, O_RDONLY | O_LARGEFILE, 0);
if (IS_ERR(file))
return PTR_ERR(file);
sbi->dif0.file = file;
if (S_ISREG(file_inode(sbi->dif0.file)->i_mode) &&
sbi->dif0.file->f_mapping->a_ops->read_folio)
return get_tree_nodev(fc, erofs_fc_fill_super);
}
return ret;
}
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_sb_info *new_sbi = fc->s_fs_info;
DBG_BUGON(!sb_rdonly(sb));
if (new_sbi->fsid || new_sbi->domain_id)
erofs_info(sb, "ignoring reconfiguration for fsid|domain_id.");
if (test_opt(&new_sbi->opt, POSIX_ACL))
fc->sb_flags |= SB_POSIXACL;
else
fc->sb_flags &= ~SB_POSIXACL;
sbi->opt = new_sbi->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->file)
fput(dif->file);
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_sb_free(struct erofs_sb_info *sbi)
{
erofs_free_dev_context(sbi->devs);
kfree(sbi->fsid);
kfree_sensitive(sbi->domain_id);
if (sbi->dif0.file)
fput(sbi->dif0.file);
kfree(sbi->volume_name);
kfree(sbi);
}
static void erofs_fc_free(struct fs_context *fc)
{
struct erofs_sb_info *sbi = fc->s_fs_info;
if (sbi)
erofs_sb_free(sbi);
}
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 int erofs_init_fs_context(struct fs_context *fc)
{
struct erofs_sb_info *sbi;
sbi = kzalloc_obj(*sbi);
if (!sbi)
return -ENOMEM;
sbi->devs = kzalloc_obj(struct erofs_dev_context);
if (!sbi->devs) {
kfree(sbi);
return -ENOMEM;
}
fc->s_fs_info = sbi;
idr_init(&sbi->devs->tree);
init_rwsem(&sbi->devs->rwsem);
erofs_default_options(sbi);
fc->ops = &erofs_context_ops;
return 0;
}
static void erofs_drop_internal_inodes(struct erofs_sb_info *sbi)
{
iput(sbi->packed_inode);
sbi->packed_inode = NULL;
iput(sbi->metabox_inode);
sbi->metabox_inode = NULL;
#ifdef CONFIG_EROFS_FS_ZIP
iput(sbi->managed_cache);
sbi->managed_cache = NULL;
#endif
}
static void erofs_kill_sb(struct super_block *sb)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
if ((IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && sbi->fsid) ||
sbi->dif0.file)
kill_anon_super(sb);
else
kill_block_super(sb);
erofs_drop_internal_inodes(sbi);
fs_put_dax(sbi->dif0.dax_dev, NULL);
erofs_fscache_unregister_fs(sb);
erofs_sb_free(sbi);
sb->s_fs_info = NULL;
}
static void erofs_put_super(struct super_block *sb)
{
struct erofs_sb_info *const sbi = EROFS_SB(sb);
erofs_unregister_sysfs(sb);
erofs_shrinker_unregister(sb);
erofs_xattr_prefixes_cleanup(sb);
erofs_drop_internal_inodes(sbi);
erofs_free_dev_context(sbi->devs);
sbi->devs = NULL;
erofs_fscache_unregister_fs(sb);
}
static 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");
#if defined(CONFIG_EROFS_FS_ONDEMAND) || defined(CONFIG_EROFS_FS_PAGE_CACHE_SHARE)
static void erofs_free_anon_inode(struct inode *inode)
{
struct erofs_inode *vi = EROFS_I(inode);
#ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE
kfree(vi->fingerprint.opaque);
#endif
kmem_cache_free(erofs_inode_cachep, vi);
}
static const struct super_operations erofs_anon_sops = {
.alloc_inode = erofs_alloc_inode,
.drop_inode = inode_just_drop,
.free_inode = erofs_free_anon_inode,
};
static int erofs_anon_init_fs_context(struct fs_context *fc)
{
struct pseudo_fs_context *ctx;
ctx = init_pseudo(fc, EROFS_SUPER_MAGIC);
if (!ctx)
return -ENOMEM;
ctx->ops = &erofs_anon_sops;
return 0;
}
struct file_system_type erofs_anon_fs_type = {
.name = "pseudo_erofs",
.init_fs_context = erofs_anon_init_fs_context,
.kill_sb = kill_anon_super,
};
#endif
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 | SLAB_ACCOUNT,
erofs_inode_init_once);
if (!erofs_inode_cachep)
return -ENOMEM;
err = erofs_init_shrinker();
if (err)
goto shrinker_err;
err = z_erofs_init_subsystem();
if (err)
goto zip_err;
err = erofs_init_sysfs();
if (err)
goto sysfs_err;
err = erofs_init_ishare();
if (err)
goto ishare_err;
err = register_filesystem(&erofs_fs_type);
if (err)
goto fs_err;
return 0;
fs_err:
erofs_exit_ishare();
ishare_err:
erofs_exit_sysfs();
sysfs_err:
z_erofs_exit_subsystem();
zip_err:
erofs_exit_shrinker();
shrinker_err:
kmem_cache_destroy(erofs_inode_cachep);
return err;
}
static void __exit erofs_module_exit(void)
{
unregister_filesystem(&erofs_fs_type);
rcu_barrier();
erofs_exit_ishare();
erofs_exit_sysfs();
z_erofs_exit_subsystem();
erofs_exit_shrinker();
kmem_cache_destroy(erofs_inode_cachep);
}
static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct erofs_sb_info *sbi = EROFS_SB(sb);
buf->f_type = sb->s_magic;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = sbi->total_blocks;
buf->f_bfree = buf->f_bavail = 0;
buf->f_files = ULLONG_MAX;
buf->f_ffree = ULLONG_MAX - sbi->inos;
buf->f_namelen = EROFS_NAME_LEN;
if (uuid_is_null(&sb->s_uuid))
buf->f_fsid = u64_to_fsid(!sb->s_bdev ? 0 :
huge_encode_dev(sb->s_bdev->bd_dev));
else
buf->f_fsid = uuid_to_fsid(sb->s_uuid.b);
return 0;
}
static int erofs_show_options(struct seq_file *seq, struct dentry *root)
{
struct erofs_sb_info *sbi = EROFS_SB(root->d_sb);
struct erofs_mount_opts *opt = &sbi->opt;
if (IS_ENABLED(CONFIG_EROFS_FS_XATTR))
seq_puts(seq, test_opt(opt, XATTR_USER) ?
",user_xattr" : ",nouser_xattr");
if (IS_ENABLED(CONFIG_EROFS_FS_POSIX_ACL))
seq_puts(seq, test_opt(opt, POSIX_ACL) ? ",acl" : ",noacl");
if (IS_ENABLED(CONFIG_EROFS_FS_ZIP))
seq_printf(seq, ",cache_strategy=%s",
erofs_param_cache_strategy[opt->cache_strategy].name);
if (test_opt(opt, DAX_ALWAYS))
seq_puts(seq, ",dax=always");
if (test_opt(opt, DAX_NEVER))
seq_puts(seq, ",dax=never");
if (erofs_is_fileio_mode(sbi) && test_opt(opt, DIRECT_IO))
seq_puts(seq, ",directio");
if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND)) {
if (sbi->fsid)
seq_printf(seq, ",fsid=%s", sbi->fsid);
if (sbi->domain_id)
seq_printf(seq, ",domain_id=%s", sbi->domain_id);
}
if (sbi->dif0.fsoff)
seq_printf(seq, ",fsoffset=%llu", sbi->dif0.fsoff);
if (test_opt(opt, INODE_SHARE))
seq_puts(seq, ",inode_share");
return 0;
}
static void erofs_evict_inode(struct inode *inode)
{
if (IS_DAX(inode))
dax_break_layout_final(inode);
erofs_ishare_free_inode(inode);
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
}
const struct super_operations erofs_sops = {
.put_super = erofs_put_super,
.alloc_inode = erofs_alloc_inode,
.free_inode = erofs_free_inode,
.evict_inode = erofs_evict_inode,
.statfs = erofs_statfs,
.show_options = erofs_show_options,
};
module_init(erofs_module_init);
module_exit(erofs_module_exit);
MODULE_DESCRIPTION("Enhanced ROM File System");
MODULE_AUTHOR("Gao Xiang, Chao Yu, Miao Xie, CONSUMER BG, HUAWEI Inc.");
MODULE_LICENSE("GPL");
