Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 789 insertions, 0 deletions

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
new file mode 100644
index 000000000..daf83e4ff
--- /dev/null
+++ b/fs/minix/inode.c
@@ -0,0 +1,789 @@
+// 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/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_sync_inode_metadata(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 #%llu: 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);
+	} else {
+		mmb_sync(&minix_i(inode)->i_metadata_bhs);
+	}
+	mmb_invalidate(&minix_i(inode)->i_metadata_bhs);
+	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;
+	mmb_init(&ei->i_metadata_bhs, &ei->vfs_inode.i_data);
+
+	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)
+{
+	/*
+	 * 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,
+	.sync_inode_metadata = minix_sync_inode_metadata,
+	.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;
+		/* 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);
+	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;
+
+	/* 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, 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;
+	}
+
+	/*
+	 * 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, 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;
+		if (!sb_set_blocksize(s, m3s->s_blocksize))
+			goto out_release;
+		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);
+
+	/* 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_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 %llu.\n",
+		       inode->i_mode, inode->i_ino);
+		make_bad_inode(inode);
+	}
+}
+
+/*
+ * 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: %llu\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;
+}
+
+/*
+ * 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: %llu\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;
+}
+
+/*
+ * 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_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);
+}
+
+/*
+ * The minix V1 function to synchronize an inode.
+ */
+static int 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 -EIO;
+	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);
+	brelse(bh);
+	set_inode_metadata_writeback(inode);
+	return 0;
+}
+
+/*
+ * The minix V2 function to synchronize an inode.
+ */
+static int 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 -EIO;
+	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);
+	brelse(bh);
+	set_inode_metadata_writeback(inode);
+	return 0;
+}
+
+static int minix_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	if (INODE_VERSION(inode) == MINIX_V1)
+		return V1_minix_update_inode(inode);
+	return V2_minix_update_inode(inode);
+}
+
+static int minix_sync_inode_metadata(struct inode *inode,
+				     struct writeback_control *wbc)
+{
+	int err = 0;
+	struct buffer_head *bh;
+	void *raw_inode;
+
+	if (INODE_VERSION(inode) == MINIX_V1)
+		raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
+	else
+		raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
+	if (!raw_inode)
+		return -EIO;
+	err = mmb_sync(&minix_i(inode)->i_metadata_bhs);
+	if (err)
+		goto out;
+	sync_dirty_buffer(bh);
+	if (buffer_write_io_error(bh)) {
+		printk("IO error syncing minix inode [%s:%08llx]\n",
+			inode->i_sb->s_id, inode->i_ino);
+		err = -EIO;
+	}
+out:
+	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 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");
+