Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 720 insertions, 0 deletions

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
new file mode 100644
index 0000000000..df575473c1
--- /dev/null
+++ b/fs/minix/inode.c
@@ -0,0 +1,720 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/minix/inode.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Copyright (C) 1996  Gertjan van Wingerde
+ *	Minix V2 fs support.
+ *
+ *  Modified for 680x0 by Andreas Schwab
+ *  Updated to filesystem version 3 by Daniel Aragones
+ */
+
+#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/vfs.h>
+#include <linux/writeback.h>
+
+static int minix_write_inode(struct inode *inode,
+		struct writeback_control *wbc);
+static int minix_statfs(struct dentry *dentry, struct kstatfs *buf);
+static int minix_remount (struct super_block * sb, int * flags, char * data);
+
+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)	 /* s_state is now out from V3 sb */
+			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_MEM_SPREAD|SLAB_ACCOUNT),
+					     init_once);
+	if (minix_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	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,
+	.remount_fs	= minix_remount,
+};
+
+static int minix_remount (struct super_block * sb, int * flags, char * data)
+{
+	struct minix_sb_info * sbi = minix_sb(sb);
+	struct minix_super_block * ms;
+
+	sync_filesystem(sb);
+	ms = sbi->s_ms;
+	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
+		return 0;
+	if (*flags & SB_RDONLY) {
+		if (ms->s_state & MINIX_VALID_FS ||
+		    !(sbi->s_mount_state & MINIX_VALID_FS))
+			return 0;
+		/* Mounting a rw partition read-only. */
+		if (sbi->s_version != MINIX_V3)
+			ms->s_state = sbi->s_mount_state;
+		mark_buffer_dirty(sbi->s_sbh);
+	} else {
+	  	/* Mount a partition which is read-only, read-write. */
+		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);
+
+	if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
+		return false;
+
+	/*
+	 * s_max_size must not exceed the block mapping limitation.  This check
+	 * is only needed for V1 filesystems, since V2/V3 support an extra level
+	 * of indirect blocks which places the limit well above U32_MAX.
+	 */
+	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, void *data, int silent)
+{
+	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;
+
+	sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
+	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;
+
+	/*
+	 * Allocate the buffer map to keep the superblock small.
+	 */
+	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);
+
+	/* Apparently minix can create filesystems that allocate more blocks for
+	 * the bitmaps than needed.  We simply ignore that, but verify it didn't
+	 * create one with not enough blocks and bail out if so.
+	 */
+	block = minix_blocks_needed(sbi->s_ninodes, s->s_blocksize);
+	if (sbi->s_imap_blocks < block) {
+		printk("MINIX-fs: file system does not have enough "
+				"imap blocks allocated.  Refusing to mount.\n");
+		goto out_no_bitmap;
+	}
+
+	block = minix_blocks_needed(
+			(sbi->s_nzones - sbi->s_firstdatazone + 1),
+			s->s_blocksize);
+	if (sbi->s_zmap_blocks < block) {
+		printk("MINIX-fs: file system does not have enough "
+				"zmap blocks allocated.  Refusing to mount.\n");
+		goto out_no_bitmap;
+	}
+
+	/* set up enough so that it can read an inode */
+	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) /* s_state is now out from V3 sb */
+			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_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_writepage(struct page *page, struct writeback_control *wbc)
+{
+	return block_write_full_page(page, minix_get_block, wbc);
+}
+
+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 page *page, loff_t pos, unsigned len)
+{
+	return __block_write_begin(page, 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(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len,
+			struct page **pagep, void **fsdata)
+{
+	int ret;
+
+	ret = block_write_begin(mapping, pos, len, pagep, 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,
+	.writepage = minix_writepage,
+	.write_begin = minix_write_begin,
+	.write_end = generic_write_end,
+	.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
+		init_special_inode(inode, inode->i_mode, rdev);
+}
+
+/*
+ * The minix V1 function to read an 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->i_mtime = inode->i_atime = 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;
+}
+
+/*
+ * The minix V2 function to read an 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->i_mtime.tv_sec = raw_inode->i_mtime;
+	inode->i_atime.tv_sec = raw_inode->i_atime;
+	inode_set_ctime(inode, raw_inode->i_ctime, 0);
+	inode->i_mtime.tv_nsec = 0;
+	inode->i_atime.tv_nsec = 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;
+}
+
+/*
+ * The global function to read an 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->i_state & I_NEW))
+		return inode;
+
+	if (INODE_VERSION(inode) == MINIX_V1)
+		return V1_minix_iget(inode);
+	else
+		return V2_minix_iget(inode);
+}
+
+/*
+ * The minix V1 function to synchronize an 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->i_mtime.tv_sec;
+	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;
+}
+
+/*
+ * The minix V2 function to synchronize an inode.
+ */
+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->i_mtime.tv_sec;
+	raw_inode->i_atime = inode->i_atime.tv_sec;
+	raw_inode->i_ctime = inode_get_ctime(inode).tv_sec;
+	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;
+}
+
+/*
+ * The function that is called for file truncation.
+ */
+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 dentry *minix_mount(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return mount_bdev(fs_type, flags, dev_name, data, minix_fill_super);
+}
+
+static struct file_system_type minix_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "minix",
+	.mount		= minix_mount,
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+};
+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_LICENSE("GPL");
+