v4.19.13 snapshot.
diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
new file mode 100644
index 0000000..273736f
--- /dev/null
+++ b/fs/sysv/inode.c
@@ -0,0 +1,364 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/sysv/inode.c
+ *
+ *  minix/inode.c
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  xenix/inode.c
+ *  Copyright (C) 1992  Doug Evans
+ *
+ *  coh/inode.c
+ *  Copyright (C) 1993  Pascal Haible, Bruno Haible
+ *
+ *  sysv/inode.c
+ *  Copyright (C) 1993  Paul B. Monday
+ *
+ *  sysv/inode.c
+ *  Copyright (C) 1993  Bruno Haible
+ *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
+ *
+ *  This file contains code for allocating/freeing inodes and for read/writing
+ *  the superblock.
+ */
+
+#include <linux/highuid.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/buffer_head.h>
+#include <linux/vfs.h>
+#include <linux/writeback.h>
+#include <linux/namei.h>
+#include <asm/byteorder.h>
+#include "sysv.h"
+
+static int sysv_sync_fs(struct super_block *sb, int wait)
+{
+	struct sysv_sb_info *sbi = SYSV_SB(sb);
+	u32 time = (u32)ktime_get_real_seconds(), old_time;
+
+	mutex_lock(&sbi->s_lock);
+
+	/*
+	 * If we are going to write out the super block,
+	 * then attach current time stamp.
+	 * But if the filesystem was marked clean, keep it clean.
+	 */
+	old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
+	if (sbi->s_type == FSTYPE_SYSV4) {
+		if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38u - old_time))
+			*sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38u - time);
+		*sbi->s_sb_time = cpu_to_fs32(sbi, time);
+		mark_buffer_dirty(sbi->s_bh2);
+	}
+
+	mutex_unlock(&sbi->s_lock);
+
+	return 0;
+}
+
+static int sysv_remount(struct super_block *sb, int *flags, char *data)
+{
+	struct sysv_sb_info *sbi = SYSV_SB(sb);
+
+	sync_filesystem(sb);
+	if (sbi->s_forced_ro)
+		*flags |= SB_RDONLY;
+	return 0;
+}
+
+static void sysv_put_super(struct super_block *sb)
+{
+	struct sysv_sb_info *sbi = SYSV_SB(sb);
+
+	if (!sb_rdonly(sb)) {
+		/* XXX ext2 also updates the state here */
+		mark_buffer_dirty(sbi->s_bh1);
+		if (sbi->s_bh1 != sbi->s_bh2)
+			mark_buffer_dirty(sbi->s_bh2);
+	}
+
+	brelse(sbi->s_bh1);
+	if (sbi->s_bh1 != sbi->s_bh2)
+		brelse(sbi->s_bh2);
+
+	kfree(sbi);
+}
+
+static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct sysv_sb_info *sbi = SYSV_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_ndatazones;
+	buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
+	buf->f_files = sbi->s_ninodes;
+	buf->f_ffree = sysv_count_free_inodes(sb);
+	buf->f_namelen = SYSV_NAMELEN;
+	buf->f_fsid.val[0] = (u32)id;
+	buf->f_fsid.val[1] = (u32)(id >> 32);
+	return 0;
+}
+
+/* 
+ * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
+ */
+static inline void read3byte(struct sysv_sb_info *sbi,
+	unsigned char * from, unsigned char * to)
+{
+	if (sbi->s_bytesex == BYTESEX_PDP) {
+		to[0] = from[0];
+		to[1] = 0;
+		to[2] = from[1];
+		to[3] = from[2];
+	} else if (sbi->s_bytesex == BYTESEX_LE) {
+		to[0] = from[0];
+		to[1] = from[1];
+		to[2] = from[2];
+		to[3] = 0;
+	} else {
+		to[0] = 0;
+		to[1] = from[0];
+		to[2] = from[1];
+		to[3] = from[2];
+	}
+}
+
+static inline void write3byte(struct sysv_sb_info *sbi,
+	unsigned char * from, unsigned char * to)
+{
+	if (sbi->s_bytesex == BYTESEX_PDP) {
+		to[0] = from[0];
+		to[1] = from[2];
+		to[2] = from[3];
+	} else if (sbi->s_bytesex == BYTESEX_LE) {
+		to[0] = from[0];
+		to[1] = from[1];
+		to[2] = from[2];
+	} else {
+		to[0] = from[1];
+		to[1] = from[2];
+		to[2] = from[3];
+	}
+}
+
+static const struct inode_operations sysv_symlink_inode_operations = {
+	.get_link	= page_get_link,
+	.getattr	= sysv_getattr,
+};
+
+void sysv_set_inode(struct inode *inode, dev_t rdev)
+{
+	if (S_ISREG(inode->i_mode)) {
+		inode->i_op = &sysv_file_inode_operations;
+		inode->i_fop = &sysv_file_operations;
+		inode->i_mapping->a_ops = &sysv_aops;
+	} else if (S_ISDIR(inode->i_mode)) {
+		inode->i_op = &sysv_dir_inode_operations;
+		inode->i_fop = &sysv_dir_operations;
+		inode->i_mapping->a_ops = &sysv_aops;
+	} else if (S_ISLNK(inode->i_mode)) {
+		inode->i_op = &sysv_symlink_inode_operations;
+		inode_nohighmem(inode);
+		inode->i_mapping->a_ops = &sysv_aops;
+	} else
+		init_special_inode(inode, inode->i_mode, rdev);
+}
+
+struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
+{
+	struct sysv_sb_info * sbi = SYSV_SB(sb);
+	struct buffer_head * bh;
+	struct sysv_inode * raw_inode;
+	struct sysv_inode_info * si;
+	struct inode *inode;
+	unsigned int block;
+
+	if (!ino || ino > sbi->s_ninodes) {
+		printk("Bad inode number on dev %s: %d is out of range\n",
+		       sb->s_id, ino);
+		return ERR_PTR(-EIO);
+	}
+
+	inode = iget_locked(sb, ino);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+	if (!(inode->i_state & I_NEW))
+		return inode;
+
+	raw_inode = sysv_raw_inode(sb, ino, &bh);
+	if (!raw_inode) {
+		printk("Major problem: unable to read inode from dev %s\n",
+		       inode->i_sb->s_id);
+		goto bad_inode;
+	}
+	/* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
+	inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
+	i_uid_write(inode, (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid));
+	i_gid_write(inode, (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid));
+	set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink));
+	inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
+	inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
+	inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
+	inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
+	inode->i_ctime.tv_nsec = 0;
+	inode->i_atime.tv_nsec = 0;
+	inode->i_mtime.tv_nsec = 0;
+	inode->i_blocks = 0;
+
+	si = SYSV_I(inode);
+	for (block = 0; block < 10+1+1+1; block++)
+		read3byte(sbi, &raw_inode->i_data[3*block],
+				(u8 *)&si->i_data[block]);
+	brelse(bh);
+	si->i_dir_start_lookup = 0;
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
+		sysv_set_inode(inode,
+			       old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
+	else
+		sysv_set_inode(inode, 0);
+	unlock_new_inode(inode);
+	return inode;
+
+bad_inode:
+	iget_failed(inode);
+	return ERR_PTR(-EIO);
+}
+
+static int __sysv_write_inode(struct inode *inode, int wait)
+{
+	struct super_block * sb = inode->i_sb;
+	struct sysv_sb_info * sbi = SYSV_SB(sb);
+	struct buffer_head * bh;
+	struct sysv_inode * raw_inode;
+	struct sysv_inode_info * si;
+	unsigned int ino, block;
+	int err = 0;
+
+	ino = inode->i_ino;
+	if (!ino || ino > sbi->s_ninodes) {
+		printk("Bad inode number on dev %s: %d is out of range\n",
+		       inode->i_sb->s_id, ino);
+		return -EIO;
+	}
+	raw_inode = sysv_raw_inode(sb, ino, &bh);
+	if (!raw_inode) {
+		printk("unable to read i-node block\n");
+		return -EIO;
+	}
+
+	raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
+	raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(i_uid_read(inode)));
+	raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(i_gid_read(inode)));
+	raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
+	raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
+	raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
+	raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
+	raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
+
+	si = SYSV_I(inode);
+	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
+		si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
+	for (block = 0; block < 10+1+1+1; block++)
+		write3byte(sbi, (u8 *)&si->i_data[block],
+			&raw_inode->i_data[3*block]);
+	mark_buffer_dirty(bh);
+	if (wait) {
+                sync_dirty_buffer(bh);
+                if (buffer_req(bh) && !buffer_uptodate(bh)) {
+                        printk ("IO error syncing sysv inode [%s:%08x]\n",
+                                sb->s_id, ino);
+                        err = -EIO;
+                }
+        }
+	brelse(bh);
+	return err;
+}
+
+int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
+}
+
+int sysv_sync_inode(struct inode *inode)
+{
+	return __sysv_write_inode(inode, 1);
+}
+
+static void sysv_evict_inode(struct inode *inode)
+{
+	truncate_inode_pages_final(&inode->i_data);
+	if (!inode->i_nlink) {
+		inode->i_size = 0;
+		sysv_truncate(inode);
+	}
+	invalidate_inode_buffers(inode);
+	clear_inode(inode);
+	if (!inode->i_nlink)
+		sysv_free_inode(inode);
+}
+
+static struct kmem_cache *sysv_inode_cachep;
+
+static struct inode *sysv_alloc_inode(struct super_block *sb)
+{
+	struct sysv_inode_info *si;
+
+	si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
+	if (!si)
+		return NULL;
+	return &si->vfs_inode;
+}
+
+static void sysv_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
+}
+
+static void sysv_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, sysv_i_callback);
+}
+
+static void init_once(void *p)
+{
+	struct sysv_inode_info *si = (struct sysv_inode_info *)p;
+
+	inode_init_once(&si->vfs_inode);
+}
+
+const struct super_operations sysv_sops = {
+	.alloc_inode	= sysv_alloc_inode,
+	.destroy_inode	= sysv_destroy_inode,
+	.write_inode	= sysv_write_inode,
+	.evict_inode	= sysv_evict_inode,
+	.put_super	= sysv_put_super,
+	.sync_fs	= sysv_sync_fs,
+	.remount_fs	= sysv_remount,
+	.statfs		= sysv_statfs,
+};
+
+int __init sysv_init_icache(void)
+{
+	sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
+			sizeof(struct sysv_inode_info), 0,
+			SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_ACCOUNT,
+			init_once);
+	if (!sysv_inode_cachep)
+		return -ENOMEM;
+	return 0;
+}
+
+void sysv_destroy_icache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(sysv_inode_cachep);
+}