#include <linux/module.h>
#include "minix.h"
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/mpage.h>
#include <linux/vfs.h>
#include <linux/writeback.h>
#include <linux/fs_context.h>
static int minix_write_inode(struct inode *inode,
struct writeback_control *wbc);
static int minix_statfs(struct dentry *dentry, struct kstatfs *buf);
void __minix_error_inode(struct inode *inode, const char *function,
unsigned int line, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
printk(KERN_CRIT "minix-fs error (device %s): %s:%d: "
"inode #%lu: comm %s: %pV\n",
inode->i_sb->s_id, function, line, inode->i_ino,
current->comm, &vaf);
va_end(args);
}
static void minix_evict_inode(struct inode *inode)
{
truncate_inode_pages_final(&inode->i_data);
if (!inode->i_nlink) {
inode->i_size = 0;
minix_truncate(inode);
}
invalidate_inode_buffers(inode);
clear_inode(inode);
if (!inode->i_nlink)
minix_free_inode(inode);
}
static void minix_put_super(struct super_block *sb)
{
int i;
struct minix_sb_info *sbi = minix_sb(sb);
if (!sb_rdonly(sb)) {
if (sbi->s_version != MINIX_V3)
sbi->s_ms->s_state = sbi->s_mount_state;
mark_buffer_dirty(sbi->s_sbh);
}
for (i = 0; i < sbi->s_imap_blocks; i++)
brelse(sbi->s_imap[i]);
for (i = 0; i < sbi->s_zmap_blocks; i++)
brelse(sbi->s_zmap[i]);
brelse (sbi->s_sbh);
kfree(sbi->s_imap);
sb->s_fs_info = NULL;
kfree(sbi);
}
static struct kmem_cache * minix_inode_cachep;
static struct inode *minix_alloc_inode(struct super_block *sb)
{
struct minix_inode_info *ei;
ei = alloc_inode_sb(sb, minix_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
return &ei->vfs_inode;
}
static void minix_free_in_core_inode(struct inode *inode)
{
kmem_cache_free(minix_inode_cachep, minix_i(inode));
}
static void init_once(void *foo)
{
struct minix_inode_info *ei = (struct minix_inode_info *) foo;
inode_init_once(&ei->vfs_inode);
}
static int __init init_inodecache(void)
{
minix_inode_cachep = kmem_cache_create("minix_inode_cache",
sizeof(struct minix_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_ACCOUNT),
init_once);
if (minix_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void destroy_inodecache(void)
{
rcu_barrier();
kmem_cache_destroy(minix_inode_cachep);
}
static const struct super_operations minix_sops = {
.alloc_inode = minix_alloc_inode,
.free_inode = minix_free_in_core_inode,
.write_inode = minix_write_inode,
.evict_inode = minix_evict_inode,
.put_super = minix_put_super,
.statfs = minix_statfs,
};
static int minix_reconfigure(struct fs_context *fc)
{
struct minix_super_block * ms;
struct super_block *sb = fc->root->d_sb;
struct minix_sb_info * sbi = sb->s_fs_info;
sync_filesystem(sb);
ms = sbi->s_ms;
if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
return 0;
if (fc->sb_flags & SB_RDONLY) {
if (ms->s_state & MINIX_VALID_FS ||
!(sbi->s_mount_state & MINIX_VALID_FS))
return 0;
if (sbi->s_version != MINIX_V3)
ms->s_state = sbi->s_mount_state;
mark_buffer_dirty(sbi->s_sbh);
} else {
if (sbi->s_version != MINIX_V3) {
sbi->s_mount_state = ms->s_state;
ms->s_state &= ~MINIX_VALID_FS;
} else {
sbi->s_mount_state = MINIX_VALID_FS;
}
mark_buffer_dirty(sbi->s_sbh);
if (!(sbi->s_mount_state & MINIX_VALID_FS))
printk("MINIX-fs warning: remounting unchecked fs, "
"running fsck is recommended\n");
else if ((sbi->s_mount_state & MINIX_ERROR_FS))
printk("MINIX-fs warning: remounting fs with errors, "
"running fsck is recommended\n");
}
return 0;
}
static bool minix_check_superblock(struct super_block *sb)
{
struct minix_sb_info *sbi = minix_sb(sb);
unsigned long block;
if (sbi->s_log_zone_size != 0) {
printk("minix-fs error: zone size must equal block size. "
"s_log_zone_size > 0 is not supported.\n");
return false;
}
if (sbi->s_ninodes < 1 || sbi->s_firstdatazone <= 4 ||
sbi->s_firstdatazone >= sbi->s_nzones)
return false;
block = minix_blocks_needed(sbi->s_ninodes, sb->s_blocksize);
if (sbi->s_imap_blocks < block) {
printk("MINIX-fs: file system does not have enough "
"imap blocks allocated. Refusing to mount.\n");
return false;
}
block = minix_blocks_needed(
(sbi->s_nzones - sbi->s_firstdatazone + 1),
sb->s_blocksize);
if (sbi->s_zmap_blocks < block) {
printk("MINIX-fs: file system does not have enough "
"zmap blocks allocated. Refusing to mount.\n");
return false;
}
if (sbi->s_version == MINIX_V1 &&
sb->s_maxbytes > (7 + 512 + 512*512) * BLOCK_SIZE)
return false;
return true;
}
static int minix_fill_super(struct super_block *s, struct fs_context *fc)
{
struct buffer_head *bh;
struct buffer_head **map;
struct minix_super_block *ms;
struct minix3_super_block *m3s = NULL;
unsigned long i, block;
struct inode *root_inode;
struct minix_sb_info *sbi;
int ret = -EINVAL;
int silent = fc->sb_flags & SB_SILENT;
sbi = kzalloc_obj(struct minix_sb_info);
if (!sbi)
return -ENOMEM;
s->s_fs_info = sbi;
BUILD_BUG_ON(32 != sizeof (struct minix_inode));
BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
if (!sb_set_blocksize(s, BLOCK_SIZE))
goto out_bad_hblock;
if (!(bh = sb_bread(s, 1)))
goto out_bad_sb;
ms = (struct minix_super_block *) bh->b_data;
sbi->s_ms = ms;
sbi->s_sbh = bh;
sbi->s_mount_state = ms->s_state;
sbi->s_ninodes = ms->s_ninodes;
sbi->s_nzones = ms->s_nzones;
sbi->s_imap_blocks = ms->s_imap_blocks;
sbi->s_zmap_blocks = ms->s_zmap_blocks;
sbi->s_firstdatazone = ms->s_firstdatazone;
sbi->s_log_zone_size = ms->s_log_zone_size;
s->s_maxbytes = ms->s_max_size;
s->s_magic = ms->s_magic;
if (s->s_magic == MINIX_SUPER_MAGIC) {
sbi->s_version = MINIX_V1;
sbi->s_dirsize = 16;
sbi->s_namelen = 14;
s->s_max_links = MINIX_LINK_MAX;
} else if (s->s_magic == MINIX_SUPER_MAGIC2) {
sbi->s_version = MINIX_V1;
sbi->s_dirsize = 32;
sbi->s_namelen = 30;
s->s_max_links = MINIX_LINK_MAX;
} else if (s->s_magic == MINIX2_SUPER_MAGIC) {
sbi->s_version = MINIX_V2;
sbi->s_nzones = ms->s_zones;
sbi->s_dirsize = 16;
sbi->s_namelen = 14;
s->s_max_links = MINIX2_LINK_MAX;
} else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
sbi->s_version = MINIX_V2;
sbi->s_nzones = ms->s_zones;
sbi->s_dirsize = 32;
sbi->s_namelen = 30;
s->s_max_links = MINIX2_LINK_MAX;
} else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
m3s = (struct minix3_super_block *) bh->b_data;
s->s_magic = m3s->s_magic;
sbi->s_imap_blocks = m3s->s_imap_blocks;
sbi->s_zmap_blocks = m3s->s_zmap_blocks;
sbi->s_firstdatazone = m3s->s_firstdatazone;
sbi->s_log_zone_size = m3s->s_log_zone_size;
s->s_maxbytes = m3s->s_max_size;
sbi->s_ninodes = m3s->s_ninodes;
sbi->s_nzones = m3s->s_zones;
sbi->s_dirsize = 64;
sbi->s_namelen = 60;
sbi->s_version = MINIX_V3;
sbi->s_mount_state = MINIX_VALID_FS;
sb_set_blocksize(s, m3s->s_blocksize);
s->s_max_links = MINIX2_LINK_MAX;
} else
goto out_no_fs;
if (!minix_check_superblock(s))
goto out_illegal_sb;
i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
map = kzalloc(i, GFP_KERNEL);
if (!map)
goto out_no_map;
sbi->s_imap = &map[0];
sbi->s_zmap = &map[sbi->s_imap_blocks];
block=2;
for (i=0 ; i < sbi->s_imap_blocks ; i++) {
if (!(sbi->s_imap[i]=sb_bread(s, block)))
goto out_no_bitmap;
block++;
}
for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
if (!(sbi->s_zmap[i]=sb_bread(s, block)))
goto out_no_bitmap;
block++;
}
minix_set_bit(0,sbi->s_imap[0]->b_data);
minix_set_bit(0,sbi->s_zmap[0]->b_data);
s->s_op = &minix_sops;
s->s_time_min = 0;
s->s_time_max = U32_MAX;
root_inode = minix_iget(s, MINIX_ROOT_INO);
if (IS_ERR(root_inode)) {
ret = PTR_ERR(root_inode);
goto out_no_root;
}
ret = -ENOMEM;
s->s_root = d_make_root(root_inode);
if (!s->s_root)
goto out_no_root;
if (!sb_rdonly(s)) {
if (sbi->s_version != MINIX_V3)
ms->s_state &= ~MINIX_VALID_FS;
mark_buffer_dirty(bh);
}
if (!(sbi->s_mount_state & MINIX_VALID_FS))
printk("MINIX-fs: mounting unchecked file system, "
"running fsck is recommended\n");
else if (sbi->s_mount_state & MINIX_ERROR_FS)
printk("MINIX-fs: mounting file system with errors, "
"running fsck is recommended\n");
return 0;
out_no_root:
if (!silent)
printk("MINIX-fs: get root inode failed\n");
goto out_freemap;
out_no_bitmap:
printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
out_freemap:
for (i = 0; i < sbi->s_imap_blocks; i++)
brelse(sbi->s_imap[i]);
for (i = 0; i < sbi->s_zmap_blocks; i++)
brelse(sbi->s_zmap[i]);
kfree(sbi->s_imap);
goto out_release;
out_no_map:
ret = -ENOMEM;
if (!silent)
printk("MINIX-fs: can't allocate map\n");
goto out_release;
out_illegal_sb:
if (!silent)
printk("MINIX-fs: bad superblock\n");
goto out_release;
out_no_fs:
if (!silent)
printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
"on device %s.\n", s->s_id);
out_release:
brelse(bh);
goto out;
out_bad_hblock:
printk("MINIX-fs: blocksize too small for device\n");
goto out;
out_bad_sb:
printk("MINIX-fs: unable to read superblock\n");
out:
s->s_fs_info = NULL;
kfree(sbi);
return ret;
}
static int minix_get_tree(struct fs_context *fc)
{
return get_tree_bdev(fc, minix_fill_super);
}
static const struct fs_context_operations minix_context_ops = {
.get_tree = minix_get_tree,
.reconfigure = minix_reconfigure,
};
static int minix_init_fs_context(struct fs_context *fc)
{
fc->ops = &minix_context_ops;
return 0;
}
static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct minix_sb_info *sbi = minix_sb(sb);
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
buf->f_type = sb->s_magic;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
buf->f_bfree = minix_count_free_blocks(sb);
buf->f_bavail = buf->f_bfree;
buf->f_files = sbi->s_ninodes;
buf->f_ffree = minix_count_free_inodes(sb);
buf->f_namelen = sbi->s_namelen;
buf->f_fsid = u64_to_fsid(id);
return 0;
}
static int minix_get_block(struct inode *inode, sector_t block,
struct buffer_head *bh_result, int create)
{
if (INODE_VERSION(inode) == MINIX_V1)
return V1_minix_get_block(inode, block, bh_result, create);
else
return V2_minix_get_block(inode, block, bh_result, create);
}
static int minix_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
return mpage_writepages(mapping, wbc, minix_get_block);
}
static int minix_read_folio(struct file *file, struct folio *folio)
{
return block_read_full_folio(folio, minix_get_block);
}
int minix_prepare_chunk(struct folio *folio, loff_t pos, unsigned len)
{
return __block_write_begin(folio, pos, len, minix_get_block);
}
static void minix_write_failed(struct address_space *mapping, loff_t to)
{
struct inode *inode = mapping->host;
if (to > inode->i_size) {
truncate_pagecache(inode, inode->i_size);
minix_truncate(inode);
}
}
static int minix_write_begin(const struct kiocb *iocb,
struct address_space *mapping,
loff_t pos, unsigned len,
struct folio **foliop, void **fsdata)
{
int ret;
ret = block_write_begin(mapping, pos, len, foliop, minix_get_block);
if (unlikely(ret))
minix_write_failed(mapping, pos + len);
return ret;
}
static sector_t minix_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping,block,minix_get_block);
}
static const struct address_space_operations minix_aops = {
.dirty_folio = block_dirty_folio,
.invalidate_folio = block_invalidate_folio,
.read_folio = minix_read_folio,
.writepages = minix_writepages,
.write_begin = minix_write_begin,
.write_end = generic_write_end,
.migrate_folio = buffer_migrate_folio,
.bmap = minix_bmap,
.direct_IO = noop_direct_IO
};
static const struct inode_operations minix_symlink_inode_operations = {
.get_link = page_get_link,
.getattr = minix_getattr,
};
void minix_set_inode(struct inode *inode, dev_t rdev)
{
if (S_ISREG(inode->i_mode)) {
inode->i_op = &minix_file_inode_operations;
inode->i_fop = &minix_file_operations;
inode->i_mapping->a_ops = &minix_aops;
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = &minix_dir_inode_operations;
inode->i_fop = &minix_dir_operations;
inode->i_mapping->a_ops = &minix_aops;
} else if (S_ISLNK(inode->i_mode)) {
inode->i_op = &minix_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_mapping->a_ops = &minix_aops;
} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
init_special_inode(inode, inode->i_mode, rdev);
} else {
printk(KERN_DEBUG "MINIX-fs: Invalid file type 0%04o for inode %lu.\n",
inode->i_mode, inode->i_ino);
make_bad_inode(inode);
}
}
static struct inode *V1_minix_iget(struct inode *inode)
{
struct buffer_head * bh;
struct minix_inode * raw_inode;
struct minix_inode_info *minix_inode = minix_i(inode);
int i;
raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
if (!raw_inode) {
iget_failed(inode);
return ERR_PTR(-EIO);
}
if (raw_inode->i_nlinks == 0) {
printk("MINIX-fs: deleted inode referenced: %lu\n",
inode->i_ino);
brelse(bh);
iget_failed(inode);
return ERR_PTR(-ESTALE);
}
inode->i_mode = raw_inode->i_mode;
i_uid_write(inode, raw_inode->i_uid);
i_gid_write(inode, raw_inode->i_gid);
set_nlink(inode, raw_inode->i_nlinks);
inode->i_size = raw_inode->i_size;
inode_set_mtime_to_ts(inode,
inode_set_atime_to_ts(inode, inode_set_ctime(inode, raw_inode->i_time, 0)));
inode->i_blocks = 0;
for (i = 0; i < 9; i++)
minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
brelse(bh);
unlock_new_inode(inode);
return inode;
}
static struct inode *V2_minix_iget(struct inode *inode)
{
struct buffer_head * bh;
struct minix2_inode * raw_inode;
struct minix_inode_info *minix_inode = minix_i(inode);
int i;
raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
if (!raw_inode) {
iget_failed(inode);
return ERR_PTR(-EIO);
}
if (raw_inode->i_nlinks == 0) {
printk("MINIX-fs: deleted inode referenced: %lu\n",
inode->i_ino);
brelse(bh);
iget_failed(inode);
return ERR_PTR(-ESTALE);
}
inode->i_mode = raw_inode->i_mode;
i_uid_write(inode, raw_inode->i_uid);
i_gid_write(inode, raw_inode->i_gid);
set_nlink(inode, raw_inode->i_nlinks);
inode->i_size = raw_inode->i_size;
inode_set_mtime(inode, raw_inode->i_mtime, 0);
inode_set_atime(inode, raw_inode->i_atime, 0);
inode_set_ctime(inode, raw_inode->i_ctime, 0);
inode->i_blocks = 0;
for (i = 0; i < 10; i++)
minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
brelse(bh);
unlock_new_inode(inode);
return inode;
}
struct inode *minix_iget(struct super_block *sb, unsigned long ino)
{
struct inode *inode;
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode_state_read_once(inode) & I_NEW))
return inode;
if (INODE_VERSION(inode) == MINIX_V1)
return V1_minix_iget(inode);
else
return V2_minix_iget(inode);
}
static struct buffer_head * V1_minix_update_inode(struct inode * inode)
{
struct buffer_head * bh;
struct minix_inode * raw_inode;
struct minix_inode_info *minix_inode = minix_i(inode);
int i;
raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
if (!raw_inode)
return NULL;
raw_inode->i_mode = inode->i_mode;
raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
raw_inode->i_nlinks = inode->i_nlink;
raw_inode->i_size = inode->i_size;
raw_inode->i_time = inode_get_mtime_sec(inode);
if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
else for (i = 0; i < 9; i++)
raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
mark_buffer_dirty(bh);
return bh;
}
static struct buffer_head * V2_minix_update_inode(struct inode * inode)
{
struct buffer_head * bh;
struct minix2_inode * raw_inode;
struct minix_inode_info *minix_inode = minix_i(inode);
int i;
raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
if (!raw_inode)
return NULL;
raw_inode->i_mode = inode->i_mode;
raw_inode->i_uid = fs_high2lowuid(i_uid_read(inode));
raw_inode->i_gid = fs_high2lowgid(i_gid_read(inode));
raw_inode->i_nlinks = inode->i_nlink;
raw_inode->i_size = inode->i_size;
raw_inode->i_mtime = inode_get_mtime_sec(inode);
raw_inode->i_atime = inode_get_atime_sec(inode);
raw_inode->i_ctime = inode_get_ctime_sec(inode);
if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
else for (i = 0; i < 10; i++)
raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
mark_buffer_dirty(bh);
return bh;
}
static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
{
int err = 0;
struct buffer_head *bh;
if (INODE_VERSION(inode) == MINIX_V1)
bh = V1_minix_update_inode(inode);
else
bh = V2_minix_update_inode(inode);
if (!bh)
return -EIO;
if (wbc->sync_mode == WB_SYNC_ALL && buffer_dirty(bh)) {
sync_dirty_buffer(bh);
if (buffer_req(bh) && !buffer_uptodate(bh)) {
printk("IO error syncing minix inode [%s:%08lx]\n",
inode->i_sb->s_id, inode->i_ino);
err = -EIO;
}
}
brelse (bh);
return err;
}
int minix_getattr(struct mnt_idmap *idmap, const struct path *path,
struct kstat *stat, u32 request_mask, unsigned int flags)
{
struct super_block *sb = path->dentry->d_sb;
struct inode *inode = d_inode(path->dentry);
generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
if (INODE_VERSION(inode) == MINIX_V1)
stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
else
stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
stat->blksize = sb->s_blocksize;
return 0;
}
void minix_truncate(struct inode * inode)
{
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
return;
if (INODE_VERSION(inode) == MINIX_V1)
V1_minix_truncate(inode);
else
V2_minix_truncate(inode);
}
static struct file_system_type minix_fs_type = {
.owner = THIS_MODULE,
.name = "minix",
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
.init_fs_context = minix_init_fs_context,
};
MODULE_ALIAS_FS("minix");
static int __init init_minix_fs(void)
{
int err = init_inodecache();
if (err)
goto out1;
err = register_filesystem(&minix_fs_type);
if (err)
goto out;
return 0;
out:
destroy_inodecache();
out1:
return err;
}
static void __exit exit_minix_fs(void)
{
unregister_filesystem(&minix_fs_type);
destroy_inodecache();
}
module_init(init_minix_fs)
module_exit(exit_minix_fs)
MODULE_DESCRIPTION("Minix file system");
MODULE_LICENSE("GPL");
