inode.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* https://www.huawei.com/
* Created by Gao Xiang <gaoxiang25@huawei.com>
*/
#include "xattr.h"
#include <trace/events/erofs.h>
/*
* if inode is successfully read, return its inode page (or sometimes
* the inode payload page if it's an extended inode) in order to fill
* inline data if possible.
*/
static struct page *erofs_read_inode(struct inode *inode,
unsigned int *ofs)
{
struct super_block *sb = inode->i_sb;
struct erofs_sb_info *sbi = EROFS_SB(sb);
struct erofs_inode *vi = EROFS_I(inode);
const erofs_off_t inode_loc = iloc(sbi, vi->nid);
erofs_blk_t blkaddr, nblks = 0;
struct page *page;
struct erofs_inode_compact *dic;
struct erofs_inode_extended *die, *copied = NULL;
unsigned int ifmt;
int err;
blkaddr = erofs_blknr(inode_loc);
*ofs = erofs_blkoff(inode_loc);
erofs_dbg("%s, reading inode nid %llu at %u of blkaddr %u",
__func__, vi->nid, *ofs, blkaddr);
page = erofs_get_meta_page(sb, blkaddr);
if (IS_ERR(page)) {
erofs_err(sb, "failed to get inode (nid: %llu) page, err %ld",
vi->nid, PTR_ERR(page));
return page;
}
dic = page_address(page) + *ofs;
ifmt = le16_to_cpu(dic->i_format);
vi->datalayout = erofs_inode_datalayout(ifmt);
if (vi->datalayout >= EROFS_INODE_DATALAYOUT_MAX) {
erofs_err(inode->i_sb, "unsupported datalayout %u of nid %llu",
vi->datalayout, vi->nid);
err = -EOPNOTSUPP;
goto err_out;
}
switch (erofs_inode_version(ifmt)) {
case EROFS_INODE_LAYOUT_EXTENDED:
vi->inode_isize = sizeof(struct erofs_inode_extended);
/* check if the inode acrosses page boundary */
if (*ofs + vi->inode_isize <= PAGE_SIZE) {
*ofs += vi->inode_isize;
die = (struct erofs_inode_extended *)dic;
} else {
const unsigned int gotten = PAGE_SIZE - *ofs;
copied = kmalloc(vi->inode_isize, GFP_NOFS);
if (!copied) {
err = -ENOMEM;
goto err_out;
}
memcpy(copied, dic, gotten);
unlock_page(page);
put_page(page);
page = erofs_get_meta_page(sb, blkaddr + 1);
if (IS_ERR(page)) {
erofs_err(sb, "failed to get inode payload page (nid: %llu), err %ld",
vi->nid, PTR_ERR(page));
kfree(copied);
return page;
}
*ofs = vi->inode_isize - gotten;
memcpy((u8 *)copied + gotten, page_address(page), *ofs);
die = copied;
}
vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
inode->i_mode = le16_to_cpu(die->i_mode);
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
case S_IFDIR:
case S_IFLNK:
vi->raw_blkaddr = le32_to_cpu(die->i_u.raw_blkaddr);
break;
case S_IFCHR:
case S_IFBLK:
inode->i_rdev =
new_decode_dev(le32_to_cpu(die->i_u.rdev));
break;
case S_IFIFO:
case S_IFSOCK:
inode->i_rdev = 0;
break;
default:
goto bogusimode;
}
i_uid_write(inode, le32_to_cpu(die->i_uid));
i_gid_write(inode, le32_to_cpu(die->i_gid));
set_nlink(inode, le32_to_cpu(die->i_nlink));
/* extended inode has its own timestamp */
inode->i_ctime.tv_sec = le64_to_cpu(die->i_ctime);
inode->i_ctime.tv_nsec = le32_to_cpu(die->i_ctime_nsec);
inode->i_size = le64_to_cpu(die->i_size);
/* total blocks for compressed files */
if (erofs_inode_is_data_compressed(vi->datalayout))
nblks = le32_to_cpu(die->i_u.compressed_blocks);
kfree(copied);
break;
case EROFS_INODE_LAYOUT_COMPACT:
vi->inode_isize = sizeof(struct erofs_inode_compact);
*ofs += vi->inode_isize;
vi->xattr_isize = erofs_xattr_ibody_size(dic->i_xattr_icount);
inode->i_mode = le16_to_cpu(dic->i_mode);
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
case S_IFDIR:
case S_IFLNK:
vi->raw_blkaddr = le32_to_cpu(dic->i_u.raw_blkaddr);
break;
case S_IFCHR:
case S_IFBLK:
inode->i_rdev =
new_decode_dev(le32_to_cpu(dic->i_u.rdev));
break;
case S_IFIFO:
case S_IFSOCK:
inode->i_rdev = 0;
break;
default:
goto bogusimode;
}
i_uid_write(inode, le16_to_cpu(dic->i_uid));
i_gid_write(inode, le16_to_cpu(dic->i_gid));
set_nlink(inode, le16_to_cpu(dic->i_nlink));
/* use build time for compact inodes */
inode->i_ctime.tv_sec = sbi->build_time;
inode->i_ctime.tv_nsec = sbi->build_time_nsec;
inode->i_size = le32_to_cpu(dic->i_size);
if (erofs_inode_is_data_compressed(vi->datalayout))
nblks = le32_to_cpu(dic->i_u.compressed_blocks);
break;
default:
erofs_err(inode->i_sb,
"unsupported on-disk inode version %u of nid %llu",
erofs_inode_version(ifmt), vi->nid);
err = -EOPNOTSUPP;
goto err_out;
}
inode->i_mtime.tv_sec = inode->i_ctime.tv_sec;
inode->i_atime.tv_sec = inode->i_ctime.tv_sec;
inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec;
inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec;
if (!nblks)
/* measure inode.i_blocks as generic filesystems */
inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
else
inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
return page;
bogusimode:
erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
inode->i_mode, vi->nid);
err = -EFSCORRUPTED;
err_out:
DBG_BUGON(1);
kfree(copied);
unlock_page(page);
put_page(page);
return ERR_PTR(err);
}
static int erofs_fill_symlink(struct inode *inode, void *data,
unsigned int m_pofs)
{
struct erofs_inode *vi = EROFS_I(inode);
char *lnk;
/* if it cannot be handled with fast symlink scheme */
if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
inode->i_size >= PAGE_SIZE) {
inode->i_op = &erofs_symlink_iops;
return 0;
}
lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
if (!lnk)
return -ENOMEM;
m_pofs += vi->xattr_isize;
/* inline symlink data shouldn't cross page boundary as well */
if (m_pofs + inode->i_size > PAGE_SIZE) {
kfree(lnk);
erofs_err(inode->i_sb,
"inline data cross block boundary @ nid %llu",
vi->nid);
DBG_BUGON(1);
return -EFSCORRUPTED;
}
memcpy(lnk, data + m_pofs, inode->i_size);
lnk[inode->i_size] = '\0';
inode->i_link = lnk;
inode->i_op = &erofs_fast_symlink_iops;
return 0;
}
static int erofs_fill_inode(struct inode *inode, int isdir)
{
struct erofs_inode *vi = EROFS_I(inode);
struct page *page;
unsigned int ofs;
int err = 0;
trace_erofs_fill_inode(inode, isdir);
/* read inode base data from disk */
page = erofs_read_inode(inode, &ofs);
if (IS_ERR(page))
return PTR_ERR(page);
/* setup the new inode */
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
inode->i_op = &erofs_generic_iops;
inode->i_fop = &generic_ro_fops;
break;
case S_IFDIR:
inode->i_op = &erofs_dir_iops;
inode->i_fop = &erofs_dir_fops;
break;
case S_IFLNK:
err = erofs_fill_symlink(inode, page_address(page), ofs);
if (err)
goto out_unlock;
inode_nohighmem(inode);
break;
case S_IFCHR:
case S_IFBLK:
case S_IFIFO:
case S_IFSOCK:
inode->i_op = &erofs_generic_iops;
init_special_inode(inode, inode->i_mode, inode->i_rdev);
goto out_unlock;
default:
err = -EFSCORRUPTED;
goto out_unlock;
}
if (erofs_inode_is_data_compressed(vi->datalayout)) {
err = z_erofs_fill_inode(inode);
goto out_unlock;
}
inode->i_mapping->a_ops = &erofs_raw_access_aops;
out_unlock:
unlock_page(page);
put_page(page);
return err;
}
/*
* erofs nid is 64bits, but i_ino is 'unsigned long', therefore
* we should do more for 32-bit platform to find the right inode.
*/
static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
{
const erofs_nid_t nid = *(erofs_nid_t *)opaque;
return EROFS_I(inode)->nid == nid;
}
static int erofs_iget_set_actor(struct inode *inode, void *opaque)
{
const erofs_nid_t nid = *(erofs_nid_t *)opaque;
inode->i_ino = erofs_inode_hash(nid);
return 0;
}
static inline struct inode *erofs_iget_locked(struct super_block *sb,
erofs_nid_t nid)
{
const unsigned long hashval = erofs_inode_hash(nid);
return iget5_locked(sb, hashval, erofs_ilookup_test_actor,
erofs_iget_set_actor, &nid);
}
struct inode *erofs_iget(struct super_block *sb,
erofs_nid_t nid,
bool isdir)
{
struct inode *inode = erofs_iget_locked(sb, nid);
if (!inode)
return ERR_PTR(-ENOMEM);
if (inode->i_state & I_NEW) {
int err;
struct erofs_inode *vi = EROFS_I(inode);
vi->nid = nid;
err = erofs_fill_inode(inode, isdir);
if (!err)
unlock_new_inode(inode);
else {
iget_failed(inode);
inode = ERR_PTR(err);
}
}
return inode;
}
int erofs_getattr(const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int query_flags)
{
struct inode *const inode = d_inode(path->dentry);
if (erofs_inode_is_data_compressed(EROFS_I(inode)->datalayout))
stat->attributes |= STATX_ATTR_COMPRESSED;
stat->attributes |= STATX_ATTR_IMMUTABLE;
stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
STATX_ATTR_IMMUTABLE);
generic_fillattr(inode, stat);
return 0;
}
const struct inode_operations erofs_generic_iops = {
.getattr = erofs_getattr,
.listxattr = erofs_listxattr,
.get_acl = erofs_get_acl,
};
const struct inode_operations erofs_symlink_iops = {
.get_link = page_get_link,
.getattr = erofs_getattr,
.listxattr = erofs_listxattr,
.get_acl = erofs_get_acl,
};
const struct inode_operations erofs_fast_symlink_iops = {
.get_link = simple_get_link,
.getattr = erofs_getattr,
.listxattr = erofs_listxattr,
.get_acl = erofs_get_acl,
};