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-rw-r--r--fs/minix/inode.c724
1 files changed, 724 insertions, 0 deletions
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
new file mode 100644
index 000000000..da8bdd171
--- /dev/null
+++ b/fs/minix/inode.c
@@ -0,0 +1,724 @@
+// 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.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
+ inode->i_mtime.tv_nsec = 0;
+ inode->i_atime.tv_nsec = 0;
+ inode->i_ctime.tv_nsec = 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->i_ctime.tv_sec = raw_inode->i_ctime;
+ inode->i_mtime.tv_nsec = 0;
+ inode->i_atime.tv_nsec = 0;
+ inode->i_ctime.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->i_ctime.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 user_namespace *mnt_userns, 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(&init_user_ns, 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");
+