Merge branch 'for-next/ramfs'

14 files changed, 826 insertions, 360 deletions

diff --git a/crypto/digest.c b/crypto/digest.c
index e67e8fba0d..d23245e15f 100644
--- a/crypto/digest.c
+++ b/crypto/digest.c
@@ -253,32 +253,12 @@ out_free:
 	return ret;
 }
 
-static int digest_update_from_memory(struct digest *d,
-				     const unsigned char *buf,
-				     loff_t size)
-{
-	while (size) {
-		unsigned long now = min_t(typeof(size), PAGE_SIZE, size);
-		int ret;
-
-		ret = digest_update_interruptible(d, buf, now);
-		if (ret)
-			return ret;
-
-		size -= now;
-		buf  += now;
-	}
-
-	return 0;
-}
-
 int digest_file_window(struct digest *d, const char *filename,
 		       unsigned char *hash,
 		       const unsigned char *sig,
 		       loff_t start, loff_t size)
 {
 	int fd, ret;
-	unsigned char *buf;
 
 	ret = digest_init(d);
 	if (ret)
@@ -290,12 +270,7 @@ int digest_file_window(struct digest *d, const char *filename,
 		return -errno;
 	}
 
-	buf = memmap(fd, PROT_READ);
-	if (buf == MAP_FAILED)
-		ret = digest_update_from_fd(d, fd, start, size);
-	else
-		ret = digest_update_from_memory(d, buf + start, size);
-
+	ret = digest_update_from_fd(d, fd, start, size);
 	if (ret)
 		goto out;
 
diff --git a/drivers/usb/gadget/pxa27x_udc.c b/drivers/usb/gadget/pxa27x_udc.c
index 442c90ca05..30c9d7db7a 100644
--- a/drivers/usb/gadget/pxa27x_udc.c
+++ b/drivers/usb/gadget/pxa27x_udc.c
@@ -341,7 +341,6 @@ static int write_packet(struct pxa_ep *ep, struct pxa27x_request *req,
 	u8 *buf_8;
 
 	buf = (u32 *)(req->req.buf + req->req.actual);
-	prefetch(buf);
 
 	length = min(req->req.length - req->req.actual, max);
 	req->req.actual += length;
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index b84da5516c..9fdef8679b 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -215,8 +215,6 @@ void musb_write_fifo(struct musb_hw_ep *hw_ep, u16 len, const u8 *src)
 	if (unlikely(len == 0))
 		return;
 
-	prefetch((u8 *)src);
-
 	dev_dbg(musb->controller, "%cX ep%d fifo %p count %d buf %p\n",
 			'T', hw_ep->epnum, fifo, len, src);
 
diff --git a/fs/cramfs/cramfs.c b/fs/cramfs/cramfs.c
index 99cbdb920c..3ea6bd437e 100644
--- a/fs/cramfs/cramfs.c
+++ b/fs/cramfs/cramfs.c
@@ -333,6 +333,15 @@ static struct inode *cramfs_alloc_inode(struct super_block *sb)
 	return &info->i_inode;
 }
 
+static void cramfs_destroy_inode(struct inode *inode)
+{
+	struct cramfs_inode_info *info;
+
+	info = to_cramfs_inode_info(inode);
+
+	free(info);
+}
+
 static int cramfs_iterate(struct file *file, struct dir_context *ctx)
 {
 	struct dentry *dentry = file->f_path.dentry;
@@ -427,6 +436,7 @@ static const struct inode_operations cramfs_symlink_inode_operations =
 
 static const struct super_operations cramfs_ops = {
 	.alloc_inode = cramfs_alloc_inode,
+	.destroy_inode = cramfs_destroy_inode,
 };
 
 static int cramfs_probe(struct device_d *dev)
diff --git a/fs/devfs.c b/fs/devfs.c
index b503f277ac..df229cca48 100644
--- a/fs/devfs.c
+++ b/fs/devfs.c
@@ -200,6 +200,13 @@ static struct inode *devfs_alloc_inode(struct super_block *sb)
 	return &node->inode;
 }
 
+static void devfs_destroy_inode(struct inode *inode)
+{
+	struct devfs_inode *node = container_of(inode, struct devfs_inode, inode);
+
+	free(node);
+}
+
 static int devfs_iterate(struct file *file, struct dir_context *ctx)
 {
 	struct cdev *cdev;
@@ -314,6 +321,7 @@ static const struct inode_operations devfs_dir_inode_operations =
 
 static const struct super_operations devfs_ops = {
 	.alloc_inode = devfs_alloc_inode,
+	.destroy_inode = devfs_destroy_inode,
 };
 
 static int devfs_probe(struct device_d *dev)
diff --git a/fs/fs.c b/fs/fs.c
index d8389323aa..e04cadfe5d 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -1087,10 +1087,15 @@ void iget_failed(struct inode *inode)
 
 void iput(struct inode *inode)
 {
-	if (!inode->i_count)
+	if (!inode)
 		return;
 
 	inode->i_count--;
+
+	if (!inode->i_count) {
+		list_del(&inode->i_sb_list);
+		destroy_inode(inode);
+	}
 }
 
 struct inode *iget(struct inode *inode)
diff --git a/fs/nfs.c b/fs/nfs.c
index 15ddab7915..6c4637281d 100644
--- a/fs/nfs.c
+++ b/fs/nfs.c
@@ -1202,6 +1202,13 @@ static struct inode *nfs_alloc_inode(struct super_block *sb)
 	return &node->inode;
 }
 
+static void nfs_destroy_inode(struct inode *inode)
+{
+	struct nfs_inode *node = nfsi(inode);
+
+	free(node);
+}
+
 static const struct inode_operations nfs_file_inode_operations;
 static const struct file_operations nfs_dir_operations;
 static const struct inode_operations nfs_dir_inode_operations;
@@ -1273,6 +1280,7 @@ static const struct inode_operations nfs_dir_inode_operations =
 
 static const struct super_operations nfs_ops = {
 	.alloc_inode = nfs_alloc_inode,
+	.destroy_inode = nfs_destroy_inode,
 };
 
 static char *rootnfsopts;
diff --git a/fs/ramfs.c b/fs/ramfs.c
index 5328775ee0..14ba877660 100644
--- a/fs/ramfs.c
+++ b/fs/ramfs.c
@@ -23,29 +23,31 @@
 #include <errno.h>
 #include <linux/stat.h>
 #include <xfuncs.h>
+#include <linux/sizes.h>
 
 #define CHUNK_SIZE	(4096 * 2)
 
 struct ramfs_chunk {
 	char *data;
-	struct ramfs_chunk *next;
+	unsigned long ofs;
+	int size;
+	struct list_head list;
 };
 
 struct ramfs_inode {
 	struct inode inode;
 	char *name;
-	struct ramfs_inode *parent;
-	struct ramfs_inode *next;
-	struct ramfs_inode *child;
 	char *symlink;
 	ulong mode;
 
-	ulong size;
-	struct ramfs_chunk *data;
+	/* bytes used in this inode */
+	unsigned long size;
+	/* bytes currently allocated for this inode */
+	unsigned long alloc_size;
+
+	struct list_head data;
 
-	/* Points to recently used chunk */
-	int recent_chunk;
-	struct ramfs_chunk *recent_chunkp;
+	struct ramfs_chunk *current_chunk;
 };
 
 static inline struct ramfs_inode *to_ramfs_inode(struct inode *inode)
@@ -53,10 +55,6 @@ static inline struct ramfs_inode *to_ramfs_inode(struct inode *inode)
 	return container_of(inode, struct ramfs_inode, inode);
 }
 
-struct ramfs_priv {
-	struct ramfs_inode root;
-};
-
 /* ---------------------------------------------------------------*/
 
 static const struct super_operations ramfs_ops;
@@ -96,18 +94,25 @@ static struct inode *ramfs_get_inode(struct super_block *sb, const struct inode
 	return inode;
 }
 
-static struct ramfs_chunk *ramfs_get_chunk(void)
+#define MIN_SIZE SZ_8K
+
+static struct ramfs_chunk *ramfs_get_chunk(unsigned long size)
 {
 	struct ramfs_chunk *data = malloc(sizeof(struct ramfs_chunk));
+
 	if (!data)
 		return NULL;
 
-	data->data = calloc(CHUNK_SIZE, 1);
+	if (size < MIN_SIZE)
+		size = MIN_SIZE;
+
+	data->data = calloc(size, 1);
 	if (!data->data) {
 		free(data);
 		return NULL;
 	}
-	data->next = NULL;
+
+	data->size = size;
 
 	return data;
 }
@@ -167,23 +172,6 @@ static int ramfs_symlink(struct inode *dir, struct dentry *dentry,
 
 static int ramfs_unlink(struct inode *dir, struct dentry *dentry)
 {
-	struct inode *inode = d_inode(dentry);
-
-	if (inode) {
-		struct ramfs_inode *node = to_ramfs_inode(inode);
-		struct ramfs_chunk *chunk = node->data;
-
-		node->data = NULL;
-
-		while (chunk) {
-			struct ramfs_chunk *tmp = chunk;
-
-			chunk = chunk->next;
-
-			ramfs_put_chunk(tmp);
-		}
-	}
-
 	return simple_unlink(dir, dentry);
 }
 
@@ -207,80 +195,57 @@ static const struct inode_operations ramfs_dir_inode_operations =
 	.create = ramfs_create,
 };
 
-static struct ramfs_chunk *ramfs_find_chunk(struct ramfs_inode *node, int chunk)
+static struct ramfs_chunk *ramfs_find_chunk(struct ramfs_inode *node,
+					    unsigned long pos, int *ofs, int *len)
 {
-	struct ramfs_chunk *data;
-	int left = chunk;
+	struct ramfs_chunk *data, *cur = node->current_chunk;
 
-	if (chunk == 0)
-		return node->data;
+	if (cur && pos >= cur->ofs)
+		data = cur;
+	else
+		data = list_first_entry(&node->data, struct ramfs_chunk, list);
 
-	if (node->recent_chunk == chunk)
-		return node->recent_chunkp;
+	list_for_each_entry_from(data, &node->data, list) {
+		if (data->ofs + data->size > pos) {
+			*ofs = pos - data->ofs;
+			*len = data->ofs + data->size - pos;
 
-	if (node->recent_chunk < chunk && node->recent_chunk != 0) {
-		/* Start at last known chunk */
-		data = node->recent_chunkp;
-		left -= node->recent_chunk;
-	} else {
-		/* Start at first chunk */
-		data = node->data;
-	}
+			node->current_chunk = data;
 
-	while (left--)
-		data = data->next;
+			return data;
+		}
+	}
 
-	node->recent_chunkp = data;
-	node->recent_chunk = chunk;
+	pr_err("%s: no chunk for pos %ld found\n", __func__, pos);
 
-	return data;
+	return NULL;
 }
 
 static int ramfs_read(struct device_d *_dev, FILE *f, void *buf, size_t insize)
 {
 	struct inode *inode = f->f_inode;
 	struct ramfs_inode *node = to_ramfs_inode(inode);
-	int chunk;
 	struct ramfs_chunk *data;
-	int ofs;
-	int now;
-	int pos = f->pos;
+	int ofs, len, now;
+	unsigned long pos = f->pos;
 	int size = insize;
 
-	chunk = pos / CHUNK_SIZE;
-	debug("%s: reading from chunk %d\n", __FUNCTION__, chunk);
+	debug("%s: %p %zu @ %lld\n", __func__, node, insize, f->pos);
+
+	while (size) {
+		data = ramfs_find_chunk(node, pos, &ofs, &len);
+		if (!data)
+			return -EINVAL;
 
-	/* Position ourself in stream */
-	data = ramfs_find_chunk(node, chunk);
-	ofs = pos % CHUNK_SIZE;
+		debug("%s: pos: %lu ofs: %d len: %d\n", __func__, pos, ofs, len);
+
+		now = min(size, len);
 
-	/* Read till end of current chunk */
-	if (ofs) {
-		now = min(size, CHUNK_SIZE - ofs);
-		debug("Reading till end of node. size: %d\n", size);
 		memcpy(buf, data->data + ofs, now);
+
 		size -= now;
-		pos += now;
 		buf += now;
-		if (pos > node->size)
-			node->size = now;
-		data = data->next;
-	}
-
-	/* Do full chunks */
-	while (size >= CHUNK_SIZE) {
-		debug("do full chunk. size: %d\n", size);
-		memcpy(buf, data->data, CHUNK_SIZE);
-		data = data->next;
-		size -= CHUNK_SIZE;
-		pos += CHUNK_SIZE;
-		buf += CHUNK_SIZE;
-	}
-
-	/* And the rest */
-	if (size) {
-		debug("do rest. size: %d\n", size);
-		memcpy(buf, data->data, size);
+		pos += now;
 	}
 
 	return insize;
@@ -290,100 +255,154 @@ static int ramfs_write(struct device_d *_dev, FILE *f, const void *buf, size_t i
 {
 	struct inode *inode = f->f_inode;
 	struct ramfs_inode *node = to_ramfs_inode(inode);
-	int chunk;
 	struct ramfs_chunk *data;
-	int ofs;
-	int now;
-	int pos = f->pos;
+	int ofs, len, now;
+	unsigned long pos = f->pos;
 	int size = insize;
 
-	chunk = f->pos / CHUNK_SIZE;
-	debug("%s: writing to chunk %d\n", __FUNCTION__, chunk);
+	debug("%s: %p %zu @ %lld\n", __func__, node, insize, f->pos);
+
+	while (size) {
+		data = ramfs_find_chunk(node, pos, &ofs, &len);
+		if (!data)
+			return -EINVAL;
 
-	/* Position ourself in stream */
-	data = ramfs_find_chunk(node, chunk);
-	ofs = f->pos % CHUNK_SIZE;
+		debug("%s: pos: %lu ofs: %d len: %d\n", __func__, pos, ofs, len);
+
+		now = min(size, len);
 
-	/* Write till end of current chunk */
-	if (ofs) {
-		now = min(size, CHUNK_SIZE - ofs);
-		debug("writing till end of node. size: %d\n", size);
 		memcpy(data->data + ofs, buf, now);
+
 		size -= now;
-		pos += now;
 		buf += now;
-		if (pos > node->size)
-			node->size = now;
-		data = data->next;
+		pos += now;
 	}
 
-	/* Do full chunks */
-	while (size >= CHUNK_SIZE) {
-		debug("do full chunk. size: %d\n", size);
-		memcpy(data->data, buf, CHUNK_SIZE);
-		data = data->next;
-		size -= CHUNK_SIZE;
-		pos += CHUNK_SIZE;
-		buf += CHUNK_SIZE;
+	return insize;
+}
+
+static void ramfs_truncate_down(struct ramfs_inode *node, unsigned long size)
+{
+	struct ramfs_chunk *data, *tmp;
+
+	list_for_each_entry_safe(data, tmp, &node->data, list) {
+		if (data->ofs >= size) {
+			list_del(&data->list);
+			node->alloc_size -= data->size;
+			ramfs_put_chunk(data);
+		}
 	}
 
-	/* And the rest */
-	if (size) {
-		debug("do rest. size: %d\n", size);
-		memcpy(data->data, buf, size);
+	node->current_chunk = NULL;
+}
+
+static int ramfs_truncate_up(struct ramfs_inode *node, unsigned long size)
+{
+	struct ramfs_chunk *data, *tmp;
+	LIST_HEAD(list);
+	unsigned long add = size - node->alloc_size;
+	unsigned long chunksize = add;
+	unsigned long alloc_size = 0;
+
+	if (node->alloc_size >= size)
+		return 0;
+
+	/*
+	 * We first try to allocate all space we need in a single chunk.
+	 * This may fail because of fragmented memory, so in case we cannot
+	 * allocate memory we successively decrease the chunk size until
+	 * we have enough allocations made.
+	 */
+	while (1) {
+		unsigned long now = min(chunksize, add);
+
+		data = ramfs_get_chunk(now);
+		if (!data) {
+			/* No luck, try with smaller chunk size */
+			chunksize >>= 1;
+
+			/* If we do not have even 128KiB then go out */
+			if (chunksize < SZ_128K)
+				goto out;
+
+			continue;
+		}
+
+		data->ofs = node->alloc_size + alloc_size;
+
+		alloc_size += data->size;
+
+		list_add_tail(&data->list, &list);
+
+		if (add <= data->size)
+			break;
+
+		add -= data->size;
 	}
 
-	return insize;
+	list_splice_tail(&list, &node->data);
+
+	node->alloc_size += alloc_size;
+
+	return 0;
+
+out:
+	list_for_each_entry_safe(data, tmp, &list, list) {
+		list_del(&data->list);
+		ramfs_put_chunk(data);
+	}
+
+	return -ENOSPC;
 }
 
 static int ramfs_truncate(struct device_d *dev, FILE *f, loff_t size)
 {
 	struct inode *inode = f->f_inode;
 	struct ramfs_inode *node = to_ramfs_inode(inode);
-	int oldchunks, newchunks;
-	struct ramfs_chunk *data = node->data;
-
-	newchunks = (size + CHUNK_SIZE - 1) / CHUNK_SIZE;
-	oldchunks = (node->size + CHUNK_SIZE - 1) / CHUNK_SIZE;
-
-	if (newchunks < oldchunks) {
-		if (!newchunks)
-			node->data = NULL;
-		while (newchunks--)
-			data = data->next;
-		while (data) {
-			struct ramfs_chunk *tmp;
-			tmp = data->next;
-			ramfs_put_chunk(data);
-			data = tmp;
-		}
-		if (node->recent_chunk > newchunks)
-			node->recent_chunk = 0;
-	}
+	int ret;
 
-	if (newchunks > oldchunks) {
-		if (data) {
-			data = ramfs_find_chunk(node, oldchunks - 1);
-		} else {
-			node->data = ramfs_get_chunk();
-			if (!node->data)
-				return -ENOMEM;
-			data = node->data;
-			oldchunks = 1;
-		}
+	/*
+	 * This is a malloc based filesystem, no need to support more
+	 * memory than fits into unsigned long.
+	 */
+	if (size > ULONG_MAX)
+		return -ENOSPC;
 
-		while (data->next)
-			data = data->next;
+	debug("%s: %p cur: %ld new: %lld alloc: %ld\n", __func__, node,
+	       node->size, size, node->alloc_size);
 
-		while (newchunks > oldchunks) {
-			data->next = ramfs_get_chunk();
-			if (!data->next)
-				return -ENOMEM;
-			data = data->next;
-			oldchunks++;
-		}
+	if (size == node->size)
+		return 0;
+
+	if (size < node->size) {
+		ramfs_truncate_down(node, size);
+	} else {
+		ret = ramfs_truncate_up(node, size);
+		if (ret)
+			return ret;
 	}
+
 	node->size = size;
+
+	return 0;
+}
+
+static int ramfs_memmap(struct device_d *_dev, FILE *f, void **map, int flags)
+{
+	struct inode *inode = f->f_inode;
+	struct ramfs_inode *node = to_ramfs_inode(inode);
+	struct ramfs_chunk *data;
+
+	if (list_empty(&node->data))
+		return -EINVAL;
+
+	if (!list_is_singular(&node->data))
+		return -EINVAL;
+
+	data = list_first_entry(&node->data, struct ramfs_chunk, list);
+
+	*map = data->data;
+
 	return 0;
 }
 
@@ -393,26 +412,31 @@ static struct inode *ramfs_alloc_inode(struct super_block *sb)
 
 	node = xzalloc(sizeof(*node));
 
+	INIT_LIST_HEAD(&node->data);
+
 	return &node->inode;
 }
 
+static void ramfs_destroy_inode(struct inode *inode)
+{
+	struct ramfs_inode *node = to_ramfs_inode(inode);
+
+	ramfs_truncate_down(node, 0);
+
+	free(node);
+}
+
 static const struct super_operations ramfs_ops = {
 	.alloc_inode = ramfs_alloc_inode,
+	.destroy_inode = ramfs_destroy_inode,
 };
 
 static int ramfs_probe(struct device_d *dev)
 {
 	struct inode *inode;
-	struct ramfs_priv *priv = xzalloc(sizeof(struct ramfs_priv));
 	struct fs_device_d *fsdev = dev_to_fs_device(dev);
 	struct super_block *sb = &fsdev->sb;
 
-	dev->priv = priv;
-
-	priv->root.name = "/";
-	priv->root.mode = S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO;
-	priv->root.parent = &priv->root;
-
 	sb->s_op = &ramfs_ops;
 
 	inode = ramfs_get_inode(sb, NULL, S_IFDIR);
@@ -429,6 +453,7 @@ static void ramfs_remove(struct device_d *dev)
 static struct fs_driver_d ramfs_driver = {
 	.read      = ramfs_read,
 	.write     = ramfs_write,
+	.memmap    = ramfs_memmap,
 	.truncate  = ramfs_truncate,
 	.flags     = FS_DRIVER_NO_DEV,
 	.drv = {
diff --git a/fs/squashfs/squashfs.c b/fs/squashfs/squashfs.c
index 38aff6d5b8..69451f7b84 100644
--- a/fs/squashfs/squashfs.c
+++ b/fs/squashfs/squashfs.c
@@ -76,8 +76,16 @@ static struct inode *squashfs_alloc_inode(struct super_block *sb)
 	return &node->vfs_inode;
 }
 
+static void squashfs_destroy_inode(struct inode *inode)
+{
+	struct squashfs_inode_info *node = squashfs_i(inode);
+
+	free(node);
+}
+
 static const struct super_operations squashfs_super_ops = {
-        .alloc_inode = squashfs_alloc_inode,
+	.alloc_inode = squashfs_alloc_inode,
+	.destroy_inode = squashfs_destroy_inode,
 };
 
 static int squashfs_probe(struct device_d *dev)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index f597c7abae..f61a458414 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -250,7 +250,6 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 		__read_once_size(&(x), __u.__c, sizeof(x));		\
 	else								\
 		__read_once_size_nocheck(&(x), __u.__c, sizeof(x));	\
-	smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \
 	__u.__val;							\
 })
 #define READ_ONCE(x) __READ_ONCE(x, 1)
diff --git a/include/linux/list.h b/include/linux/list.h
index af5edc9a76..1341806b59 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -1,7 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_LIST_H
 #define _LINUX_LIST_H
 
-#include <linux/stddef.h> /* for NULL */
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/poison.h>
+#include <linux/const.h>
 #include <linux/kernel.h>
 
 /*
@@ -14,46 +18,60 @@
  * using the generic single-entry routines.
  */
 
-#define LIST_POISON1  ((void *) 0x00100100)
-#define LIST_POISON2  ((void *) 0x00200200)
-static inline void prefetch(const void *x) {;}
-
-struct list_head {
-	struct list_head *next, *prev;
-};
-
 #define LIST_HEAD_INIT(name) { &(name), &(name) }
 
 #define LIST_HEAD(name) \
 	struct list_head name = LIST_HEAD_INIT(name)
 
+/**
+ * INIT_LIST_HEAD - Initialize a list_head structure
+ * @list: list_head structure to be initialized.
+ *
+ * Initializes the list_head to point to itself.  If it is a list header,
+ * the result is an empty list.
+ */
 static inline void INIT_LIST_HEAD(struct list_head *list)
 {
-	list->next = list;
+	WRITE_ONCE(list->next, list);
 	list->prev = list;
 }
 
+#ifdef CONFIG_DEBUG_LIST
+extern bool __list_add_valid(struct list_head *new,
+			      struct list_head *prev,
+			      struct list_head *next);
+extern bool __list_del_entry_valid(struct list_head *entry);
+#else
+static inline bool __list_add_valid(struct list_head *new,
+				struct list_head *prev,
+				struct list_head *next)
+{
+	return true;
+}
+static inline bool __list_del_entry_valid(struct list_head *entry)
+{
+	return true;
+}
+#endif
+
 /*
  * Insert a new entry between two known consecutive entries.
  *
  * This is only for internal list manipulation where we know
  * the prev/next entries already!
  */
-#ifndef CONFIG_DEBUG_LIST
 static inline void __list_add(struct list_head *new,
 			      struct list_head *prev,
 			      struct list_head *next)
 {
+	if (!__list_add_valid(new, prev, next))
+		return;
+
 	next->prev = new;
 	new->next = next;
 	new->prev = prev;
-	prev->next = new;
+	WRITE_ONCE(prev->next, new);
 }
-#else
-extern void __list_add(struct list_head *new,
-			      struct list_head *prev,
-			      struct list_head *next);
-#endif
 
 /**
  * list_add - add a new entry
@@ -63,14 +81,10 @@ extern void __list_add(struct list_head *new,
  * Insert a new entry after the specified head.
  * This is good for implementing stacks.
  */
-#ifndef CONFIG_DEBUG_LIST
 static inline void list_add(struct list_head *new, struct list_head *head)
 {
 	__list_add(new, head, head->next);
 }
-#else
-extern void list_add(struct list_head *new, struct list_head *head);
-#endif
 
 
 /**
@@ -96,7 +110,29 @@ static inline void list_add_tail(struct list_head *new, struct list_head *head)
 static inline void __list_del(struct list_head * prev, struct list_head * next)
 {
 	next->prev = prev;
-	prev->next = next;
+	WRITE_ONCE(prev->next, next);
+}
+
+/*
+ * Delete a list entry and clear the 'prev' pointer.
+ *
+ * This is a special-purpose list clearing method used in the networking code
+ * for lists allocated as per-cpu, where we don't want to incur the extra
+ * WRITE_ONCE() overhead of a regular list_del_init(). The code that uses this
+ * needs to check the node 'prev' pointer instead of calling list_empty().
+ */
+static inline void __list_del_clearprev(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+	entry->prev = NULL;
+}
+
+static inline void __list_del_entry(struct list_head *entry)
+{
+	if (!__list_del_entry_valid(entry))
+		return;
+
+	__list_del(entry->prev, entry->next);
 }
 
 /**
@@ -105,16 +141,12 @@ static inline void __list_del(struct list_head * prev, struct list_head * next)
  * Note: list_empty() on entry does not return true after this, the entry is
  * in an undefined state.
  */
-#ifndef CONFIG_DEBUG_LIST
 static inline void list_del(struct list_head *entry)
 {
-	__list_del(entry->prev, entry->next);
+	__list_del_entry(entry);
 	entry->next = LIST_POISON1;
 	entry->prev = LIST_POISON2;
 }
-#else
-extern void list_del(struct list_head *entry);
-#endif
 
 /**
  * list_replace - replace old entry by new one
@@ -132,20 +164,44 @@ static inline void list_replace(struct list_head *old,
 	new->prev->next = new;
 }
 
+/**
+ * list_replace_init - replace old entry by new one and initialize the old one
+ * @old : the element to be replaced
+ * @new : the new element to insert
+ *
+ * If @old was empty, it will be overwritten.
+ */
 static inline void list_replace_init(struct list_head *old,
-					struct list_head *new)
+				     struct list_head *new)
 {
 	list_replace(old, new);
 	INIT_LIST_HEAD(old);
 }
 
 /**
+ * list_swap - replace entry1 with entry2 and re-add entry1 at entry2's position
+ * @entry1: the location to place entry2
+ * @entry2: the location to place entry1
+ */
+static inline void list_swap(struct list_head *entry1,
+			     struct list_head *entry2)
+{
+	struct list_head *pos = entry2->prev;
+
+	list_del(entry2);
+	list_replace(entry1, entry2);
+	if (pos == entry1)
+		pos = entry2;
+	list_add(entry1, pos);
+}
+
+/**
  * list_del_init - deletes entry from list and reinitialize it.
  * @entry: the element to delete from the list.
  */
 static inline void list_del_init(struct list_head *entry)
 {
-	__list_del(entry->prev, entry->next);
+	__list_del_entry(entry);
 	INIT_LIST_HEAD(entry);
 }
 
@@ -156,7 +212,7 @@ static inline void list_del_init(struct list_head *entry)
  */
 static inline void list_move(struct list_head *list, struct list_head *head)
 {
-	__list_del(list->prev, list->next);
+	__list_del_entry(list);
 	list_add(list, head);
 }
 
@@ -168,11 +224,45 @@ static inline void list_move(struct list_head *list, struct list_head *head)
 static inline void list_move_tail(struct list_head *list,
 				  struct list_head *head)
 {
-	__list_del(list->prev, list->next);
+	__list_del_entry(list);
 	list_add_tail(list, head);
 }
 
 /**
+ * list_bulk_move_tail - move a subsection of a list to its tail
+ * @head: the head that will follow our entry
+ * @first: first entry to move
+ * @last: last entry to move, can be the same as first
+ *
+ * Move all entries between @first and including @last before @head.
+ * All three entries must belong to the same linked list.
+ */
+static inline void list_bulk_move_tail(struct list_head *head,
+				       struct list_head *first,
+				       struct list_head *last)
+{
+	first->prev->next = last->next;
+	last->next->prev = first->prev;
+
+	head->prev->next = first;
+	first->prev = head->prev;
+
+	last->next = head;
+	head->prev = last;
+}
+
+/**
+ * list_is_first -- tests whether @list is the first entry in list @head
+ * @list: the entry to test
+ * @head: the head of the list
+ */
+static inline int list_is_first(const struct list_head *list,
+					const struct list_head *head)
+{
+	return list->prev == head;
+}
+
+/**
  * list_is_last - tests whether @list is the last entry in list @head
  * @list: the entry to test
  * @head: the head of the list
@@ -189,7 +279,7 @@ static inline int list_is_last(const struct list_head *list,
  */
 static inline int list_empty(const struct list_head *head)
 {
-	return head->next == head;
+	return READ_ONCE(head->next) == head;
 }
 
 /**
@@ -212,6 +302,38 @@ static inline int list_empty_careful(const struct list_head *head)
 }
 
 /**
+ * list_rotate_left - rotate the list to the left
+ * @head: the head of the list
+ */
+static inline void list_rotate_left(struct list_head *head)
+{
+	struct list_head *first;
+
+	if (!list_empty(head)) {
+		first = head->next;
+		list_move_tail(first, head);
+	}
+}
+
+/**
+ * list_rotate_to_front() - Rotate list to specific item.
+ * @list: The desired new front of the list.
+ * @head: The head of the list.
+ *
+ * Rotates list so that @list becomes the new front of the list.
+ */
+static inline void list_rotate_to_front(struct list_head *list,
+					struct list_head *head)
+{
+	/*
+	 * Deletes the list head from the list denoted by @head and
+	 * places it as the tail of @list, this effectively rotates the
+	 * list so that @list is at the front.
+	 */
+	list_move_tail(head, list);
+}
+
+/**
  * list_is_singular - tests whether a list has just one entry.
  * @head: the list to test.
  */
@@ -220,29 +342,112 @@ static inline int list_is_singular(const struct list_head *head)
 	return !list_empty(head) && (head->next == head->prev);
 }
 
-static inline void __list_splice(struct list_head *list,
-				 struct list_head *head)
+static inline void __list_cut_position(struct list_head *list,
+		struct list_head *head, struct list_head *entry)
+{
+	struct list_head *new_first = entry->next;
+	list->next = head->next;
+	list->next->prev = list;
+	list->prev = entry;
+	entry->next = list;
+	head->next = new_first;
+	new_first->prev = head;
+}
+
+/**
+ * list_cut_position - cut a list into two
+ * @list: a new list to add all removed entries
+ * @head: a list with entries
+ * @entry: an entry within head, could be the head itself
+ *	and if so we won't cut the list
+ *
+ * This helper moves the initial part of @head, up to and
+ * including @entry, from @head to @list. You should
+ * pass on @entry an element you know is on @head. @list
+ * should be an empty list or a list you do not care about
+ * losing its data.
+ *
+ */
+static inline void list_cut_position(struct list_head *list,
+		struct list_head *head, struct list_head *entry)
+{
+	if (list_empty(head))
+		return;
+	if (list_is_singular(head) &&
+		(head->next != entry && head != entry))
+		return;
+	if (entry == head)
+		INIT_LIST_HEAD(list);
+	else
+		__list_cut_position(list, head, entry);
+}
+
+/**
+ * list_cut_before - cut a list into two, before given entry
+ * @list: a new list to add all removed entries
+ * @head: a list with entries
+ * @entry: an entry within head, could be the head itself
+ *
+ * This helper moves the initial part of @head, up to but
+ * excluding @entry, from @head to @list.  You should pass
+ * in @entry an element you know is on @head.  @list should
+ * be an empty list or a list you do not care about losing
+ * its data.
+ * If @entry == @head, all entries on @head are moved to
+ * @list.
+ */
+static inline void list_cut_before(struct list_head *list,
+				   struct list_head *head,
+				   struct list_head *entry)
+{
+	if (head->next == entry) {
+		INIT_LIST_HEAD(list);
+		return;
+	}
+	list->next = head->next;
+	list->next->prev = list;
+	list->prev = entry->prev;
+	list->prev->next = list;
+	head->next = entry;
+	entry->prev = head;
+}
+
+static inline void __list_splice(const struct list_head *list,
+				 struct list_head *prev,
+				 struct list_head *next)
 {
 	struct list_head *first = list->next;
 	struct list_head *last = list->prev;
-	struct list_head *at = head->next;
 
-	first->prev = head;
-	head->next = first;
+	first->prev = prev;
+	prev->next = first;
 
-	last->next = at;
-	at->prev = last;
+	last->next = next;
+	next->prev = last;
+}
+
+/**
+ * list_splice - join two lists, this is designed for stacks
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static inline void list_splice(const struct list_head *list,
+				struct list_head *head)
+{
+	if (!list_empty(list))
+		__list_splice(list, head, head->next);
 }
 
 /**
- * list_splice - join two lists
+ * list_splice_tail - join two lists, each list being a queue
  * @list: the new list to add.
  * @head: the place to add it in the first list.
  */
-static inline void list_splice(struct list_head *list, struct list_head *head)
+static inline void list_splice_tail(struct list_head *list,
+				struct list_head *head)
 {
 	if (!list_empty(list))
-		__list_splice(list, head);
+		__list_splice(list, head->prev, head);
 }
 
 /**
@@ -256,7 +461,24 @@ static inline void list_splice_init(struct list_head *list,
 				    struct list_head *head)
 {
 	if (!list_empty(list)) {
-		__list_splice(list, head);
+		__list_splice(list, head, head->next);
+		INIT_LIST_HEAD(list);
+	}
+}
+
+/**
+ * list_splice_tail_init - join two lists and reinitialise the emptied list
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ *
+ * Each of the lists is a queue.
+ * The list at @list is reinitialised
+ */
+static inline void list_splice_tail_init(struct list_head *list,
+					 struct list_head *head)
+{
+	if (!list_empty(list)) {
+		__list_splice(list, head->prev, head);
 		INIT_LIST_HEAD(list);
 	}
 }
@@ -265,7 +487,7 @@ static inline void list_splice_init(struct list_head *list,
  * list_entry - get the struct for this entry
  * @ptr:	the &struct list_head pointer.
  * @type:	the type of the struct this is embedded in.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  */
 #define list_entry(ptr, type, member) \
 	container_of(ptr, type, member)
@@ -274,7 +496,7 @@ static inline void list_splice_init(struct list_head *list,
  * list_first_entry - get the first element from a list
  * @ptr:	the list head to take the element from.
  * @type:	the type of the struct this is embedded in.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  *
  * Note, that list is expected to be not empty.
  */
@@ -283,25 +505,44 @@ static inline void list_splice_init(struct list_head *list,
 
 /**
  * list_last_entry - get the last element from a list
- * @head: the list head to take the element from.
- * @type: the type of the struct this is embedded in.
- * @member: the name of the list_struct within the struct.
+ * @ptr:	the list head to take the element from.
+ * @type:	the type of the struct this is embedded in.
+ * @member:	the name of the list_head within the struct.
  *
  * Note, that list is expected to be not empty.
  */
-#define list_last_entry(head, type, member) \
-	list_entry((head)->prev, type, member)
+#define list_last_entry(ptr, type, member) \
+	list_entry((ptr)->prev, type, member)
 
 /**
  * list_first_entry_or_null - get the first element from a list
  * @ptr:	the list head to take the element from.
  * @type:	the type of the struct this is embedded in.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  *
  * Note that if the list is empty, it returns NULL.
  */
-#define list_first_entry_or_null(ptr, type, member) \
-	(!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL)
+#define list_first_entry_or_null(ptr, type, member) ({ \
+	struct list_head *head__ = (ptr); \
+	struct list_head *pos__ = READ_ONCE(head__->next); \
+	pos__ != head__ ? list_entry(pos__, type, member) : NULL; \
+})
+
+/**
+ * list_next_entry - get the next element in list
+ * @pos:	the type * to cursor
+ * @member:	the name of the list_head within the struct.
+ */
+#define list_next_entry(pos, member) \
+	list_entry((pos)->member.next, typeof(*(pos)), member)
+
+/**
+ * list_prev_entry - get the prev element in list
+ * @pos:	the type * to cursor
+ * @member:	the name of the list_head within the struct.
+ */
+#define list_prev_entry(pos, member) \
+	list_entry((pos)->member.prev, typeof(*(pos)), member)
 
 /**
  * list_for_each	-	iterate over a list
@@ -309,21 +550,17 @@ static inline void list_splice_init(struct list_head *list,
  * @head:	the head for your list.
  */
 #define list_for_each(pos, head) \
-	for (pos = (head)->next; prefetch(pos->next), pos != (head); \
-		pos = pos->next)
+	for (pos = (head)->next; pos != (head); pos = pos->next)
 
 /**
- * __list_for_each	-	iterate over a list
+ * list_for_each_continue - continue iteration over a list
  * @pos:	the &struct list_head to use as a loop cursor.
  * @head:	the head for your list.
  *
- * This variant differs from list_for_each() in that it's the
- * simplest possible list iteration code, no prefetching is done.
- * Use this for code that knows the list to be very short (empty
- * or 1 entry) most of the time.
+ * Continue to iterate over a list, continuing after the current position.
  */
-#define __list_for_each(pos, head) \
-	for (pos = (head)->next; pos != (head); pos = pos->next)
+#define list_for_each_continue(pos, head) \
+	for (pos = pos->next; pos != (head); pos = pos->next)
 
 /**
  * list_for_each_prev	-	iterate over a list backwards
@@ -331,8 +568,7 @@ static inline void list_splice_init(struct list_head *list,
  * @head:	the head for your list.
  */
 #define list_for_each_prev(pos, head) \
-	for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \
-		pos = pos->prev)
+	for (pos = (head)->prev; pos != (head); pos = pos->prev)
 
 /**
  * list_for_each_safe - iterate over a list safe against removal of list entry
@@ -345,32 +581,43 @@ static inline void list_splice_init(struct list_head *list,
 		pos = n, n = pos->next)
 
 /**
+ * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
+ * @pos:	the &struct list_head to use as a loop cursor.
+ * @n:		another &struct list_head to use as temporary storage
+ * @head:	the head for your list.
+ */
+#define list_for_each_prev_safe(pos, n, head) \
+	for (pos = (head)->prev, n = pos->prev; \
+	     pos != (head); \
+	     pos = n, n = pos->prev)
+
+/**
  * list_for_each_entry	-	iterate over list of given type
  * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  */
 #define list_for_each_entry(pos, head, member)				\
-	for (pos = list_entry((head)->next, typeof(*pos), member);	\
-	     prefetch(pos->member.next), &pos->member != (head); 	\
-	     pos = list_entry(pos->member.next, typeof(*pos), member))
+	for (pos = list_first_entry(head, typeof(*pos), member);	\
+	     &pos->member != (head);					\
+	     pos = list_next_entry(pos, member))
 
 /**
  * list_for_each_entry_reverse - iterate backwards over list of given type.
  * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  */
 #define list_for_each_entry_reverse(pos, head, member)			\
-	for (pos = list_entry((head)->prev, typeof(*pos), member);	\
-	     prefetch(pos->member.prev), &pos->member != (head); 	\
-	     pos = list_entry(pos->member.prev, typeof(*pos), member))
+	for (pos = list_last_entry(head, typeof(*pos), member);		\
+	     &pos->member != (head); 					\
+	     pos = list_prev_entry(pos, member))
 
 /**
  * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
  * @pos:	the type * to use as a start point
  * @head:	the head of the list
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  *
  * Prepares a pos entry for use as a start point in list_for_each_entry_continue().
  */
@@ -381,87 +628,129 @@ static inline void list_splice_init(struct list_head *list,
  * list_for_each_entry_continue - continue iteration over list of given type
  * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  *
  * Continue to iterate over list of given type, continuing after
  * the current position.
  */
 #define list_for_each_entry_continue(pos, head, member) 		\
-	for (pos = list_entry(pos->member.next, typeof(*pos), member);	\
-	     prefetch(pos->member.next), &pos->member != (head);	\
-	     pos = list_entry(pos->member.next, typeof(*pos), member))
+	for (pos = list_next_entry(pos, member);			\
+	     &pos->member != (head);					\
+	     pos = list_next_entry(pos, member))
+
+/**
+ * list_for_each_entry_continue_reverse - iterate backwards from the given point
+ * @pos:	the type * to use as a loop cursor.
+ * @head:	the head for your list.
+ * @member:	the name of the list_head within the struct.
+ *
+ * Start to iterate over list of given type backwards, continuing after
+ * the current position.
+ */
+#define list_for_each_entry_continue_reverse(pos, head, member)		\
+	for (pos = list_prev_entry(pos, member);			\
+	     &pos->member != (head);					\
+	     pos = list_prev_entry(pos, member))
 
 /**
  * list_for_each_entry_from - iterate over list of given type from the current point
  * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  *
  * Iterate over list of given type, continuing from current position.
  */
 #define list_for_each_entry_from(pos, head, member) 			\
-	for (; prefetch(pos->member.next), &pos->member != (head);	\
-	     pos = list_entry(pos->member.next, typeof(*pos), member))
+	for (; &pos->member != (head);					\
+	     pos = list_next_entry(pos, member))
+
+/**
+ * list_for_each_entry_from_reverse - iterate backwards over list of given type
+ *                                    from the current point
+ * @pos:	the type * to use as a loop cursor.
+ * @head:	the head for your list.
+ * @member:	the name of the list_head within the struct.
+ *
+ * Iterate backwards over list of given type, continuing from current position.
+ */
+#define list_for_each_entry_from_reverse(pos, head, member)		\
+	for (; &pos->member != (head);					\
+	     pos = list_prev_entry(pos, member))
 
 /**
  * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
  * @pos:	the type * to use as a loop cursor.
  * @n:		another type * to use as temporary storage
  * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  */
 #define list_for_each_entry_safe(pos, n, head, member)			\
-	for (pos = list_entry((head)->next, typeof(*pos), member),	\
-		n = list_entry(pos->member.next, typeof(*pos), member);	\
+	for (pos = list_first_entry(head, typeof(*pos), member),	\
+		n = list_next_entry(pos, member);			\
 	     &pos->member != (head); 					\
-	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
+	     pos = n, n = list_next_entry(n, member))
 
 /**
- * list_for_each_entry_safe_continue
+ * list_for_each_entry_safe_continue - continue list iteration safe against removal
  * @pos:	the type * to use as a loop cursor.
  * @n:		another type * to use as temporary storage
  * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  *
  * Iterate over list of given type, continuing after current point,
  * safe against removal of list entry.
  */
 #define list_for_each_entry_safe_continue(pos, n, head, member) 		\
-	for (pos = list_entry(pos->member.next, typeof(*pos), member), 		\
-		n = list_entry(pos->member.next, typeof(*pos), member);		\
+	for (pos = list_next_entry(pos, member), 				\
+		n = list_next_entry(pos, member);				\
 	     &pos->member != (head);						\
-	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
+	     pos = n, n = list_next_entry(n, member))
 
 /**
- * list_for_each_entry_safe_from
+ * list_for_each_entry_safe_from - iterate over list from current point safe against removal
  * @pos:	the type * to use as a loop cursor.
  * @n:		another type * to use as temporary storage
  * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  *
  * Iterate over list of given type from current point, safe against
  * removal of list entry.
  */
 #define list_for_each_entry_safe_from(pos, n, head, member) 			\
-	for (n = list_entry(pos->member.next, typeof(*pos), member);		\
+	for (n = list_next_entry(pos, member);					\
 	     &pos->member != (head);						\
-	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
+	     pos = n, n = list_next_entry(n, member))
 
 /**
- * list_for_each_entry_safe_reverse
+ * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal
  * @pos:	the type * to use as a loop cursor.
  * @n:		another type * to use as temporary storage
  * @head:	the head for your list.
- * @member:	the name of the list_struct within the struct.
+ * @member:	the name of the list_head within the struct.
  *
  * Iterate backwards over list of given type, safe against removal
  * of list entry.
  */
 #define list_for_each_entry_safe_reverse(pos, n, head, member)		\
-	for (pos = list_entry((head)->prev, typeof(*pos), member),	\
-		n = list_entry(pos->member.prev, typeof(*pos), member);	\
+	for (pos = list_last_entry(head, typeof(*pos), member),		\
+		n = list_prev_entry(pos, member);			\
 	     &pos->member != (head); 					\
-	     pos = n, n = list_entry(n->member.prev, typeof(*n), member))
+	     pos = n, n = list_prev_entry(n, member))
+
+/**
+ * list_safe_reset_next - reset a stale list_for_each_entry_safe loop
+ * @pos:	the loop cursor used in the list_for_each_entry_safe loop
+ * @n:		temporary storage used in list_for_each_entry_safe
+ * @member:	the name of the list_head within the struct.
+ *
+ * list_safe_reset_next is not safe to use in general if the list may be
+ * modified concurrently (eg. the lock is dropped in the loop body). An
+ * exception to this is if the cursor element (pos) is pinned in the list,
+ * and list_safe_reset_next is called after re-taking the lock and before
+ * completing the current iteration of the loop body.
+ */
+#define list_safe_reset_next(pos, n, member)				\
+	n = list_next_entry(pos, member)
 
 /**
  * list_add_sort - add a new entry to a sorted list
@@ -473,7 +762,7 @@ static inline void list_splice_init(struct list_head *list,
  * This is useful for implementing queues.
  */
 static inline void list_add_sort(struct list_head *new, struct list_head *head,
-		int (*compare)(struct list_head *a, struct list_head *b))
+               int (*compare)(struct list_head *a, struct list_head *b))
 {
 	struct list_head *pos, *insert = head;
 
@@ -494,14 +783,6 @@ static inline void list_add_sort(struct list_head *new, struct list_head *head,
  * You lose the ability to access the tail in O(1).
  */
 
-struct hlist_head {
-	struct hlist_node *first;
-};
-
-struct hlist_node {
-	struct hlist_node *next, **pprev;
-};
-
 #define HLIST_HEAD_INIT { .first = NULL }
 #define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
 #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
@@ -511,25 +792,58 @@ static inline void INIT_HLIST_NODE(struct hlist_node *h)
 	h->pprev = NULL;
 }
 
+/**
+ * hlist_unhashed - Has node been removed from list and reinitialized?
+ * @h: Node to be checked
+ *
+ * Not that not all removal functions will leave a node in unhashed
+ * state.  For example, hlist_nulls_del_init_rcu() does leave the
+ * node in unhashed state, but hlist_nulls_del() does not.
+ */
 static inline int hlist_unhashed(const struct hlist_node *h)
 {
 	return !h->pprev;
 }
 
+/**
+ * hlist_unhashed_lockless - Version of hlist_unhashed for lockless use
+ * @h: Node to be checked
+ *
+ * This variant of hlist_unhashed() must be used in lockless contexts
+ * to avoid potential load-tearing.  The READ_ONCE() is paired with the
+ * various WRITE_ONCE() in hlist helpers that are defined below.
+ */
+static inline int hlist_unhashed_lockless(const struct hlist_node *h)
+{
+	return !READ_ONCE(h->pprev);
+}
+
+/**
+ * hlist_empty - Is the specified hlist_head structure an empty hlist?
+ * @h: Structure to check.
+ */
 static inline int hlist_empty(const struct hlist_head *h)
 {
-	return !h->first;
+	return !READ_ONCE(h->first);
 }
 
 static inline void __hlist_del(struct hlist_node *n)
 {
 	struct hlist_node *next = n->next;
 	struct hlist_node **pprev = n->pprev;
-	*pprev = next;
+
+	WRITE_ONCE(*pprev, next);
 	if (next)
-		next->pprev = pprev;
+		WRITE_ONCE(next->pprev, pprev);
 }
 
+/**
+ * hlist_del - Delete the specified hlist_node from its list
+ * @n: Node to delete.
+ *
+ * Note that this function leaves the node in hashed state.  Use
+ * hlist_del_init() or similar instead to unhash @n.
+ */
 static inline void hlist_del(struct hlist_node *n)
 {
 	__hlist_del(n);
@@ -537,6 +851,12 @@ static inline void hlist_del(struct hlist_node *n)
 	n->pprev = LIST_POISON2;
 }
 
+/**
+ * hlist_del_init - Delete the specified hlist_node from its list and initialize
+ * @n: Node to delete.
+ *
+ * Note that this function leaves the node in unhashed state.
+ */
 static inline void hlist_del_init(struct hlist_node *n)
 {
 	if (!hlist_unhashed(n)) {
@@ -545,95 +865,161 @@ static inline void hlist_del_init(struct hlist_node *n)
 	}
 }
 
+/**
+ * hlist_add_head - add a new entry at the beginning of the hlist
+ * @n: new entry to be added
+ * @h: hlist head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
 static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
 {
 	struct hlist_node *first = h->first;
-	n->next = first;
+	WRITE_ONCE(n->next, first);
 	if (first)
-		first->pprev = &n->next;
-	h->first = n;
-	n->pprev = &h->first;
+		WRITE_ONCE(first->pprev, &n->next);
+	WRITE_ONCE(h->first, n);
+	WRITE_ONCE(n->pprev, &h->first);
 }
 
-/* next must be != NULL */
+/**
+ * hlist_add_before - add a new entry before the one specified
+ * @n: new entry to be added
+ * @next: hlist node to add it before, which must be non-NULL
+ */
 static inline void hlist_add_before(struct hlist_node *n,
-					struct hlist_node *next)
+				    struct hlist_node *next)
+{
+	WRITE_ONCE(n->pprev, next->pprev);
+	WRITE_ONCE(n->next, next);
+	WRITE_ONCE(next->pprev, &n->next);
+	WRITE_ONCE(*(n->pprev), n);
+}
+
+/**
+ * hlist_add_behing - add a new entry after the one specified
+ * @n: new entry to be added
+ * @prev: hlist node to add it after, which must be non-NULL
+ */
+static inline void hlist_add_behind(struct hlist_node *n,
+				    struct hlist_node *prev)
 {
-	n->pprev = next->pprev;
-	n->next = next;
-	next->pprev = &n->next;
-	*(n->pprev) = n;
+	WRITE_ONCE(n->next, prev->next);
+	WRITE_ONCE(prev->next, n);
+	WRITE_ONCE(n->pprev, &prev->next);
+
+	if (n->next)
+		WRITE_ONCE(n->next->pprev, &n->next);
+}
+
+/**
+ * hlist_add_fake - create a fake hlist consisting of a single headless node
+ * @n: Node to make a fake list out of
+ *
+ * This makes @n appear to be its own predecessor on a headless hlist.
+ * The point of this is to allow things like hlist_del() to work correctly
+ * in cases where there is no list.
+ */
+static inline void hlist_add_fake(struct hlist_node *n)
+{
+	n->pprev = &n->next;
 }
 
-static inline void hlist_add_after(struct hlist_node *n,
-					struct hlist_node *next)
+/**
+ * hlist_fake: Is this node a fake hlist?
+ * @h: Node to check for being a self-referential fake hlist.
+ */
+static inline bool hlist_fake(struct hlist_node *h)
+{
+	return h->pprev == &h->next;
+}
+
+/**
+ * hlist_is_singular_node - is node the only element of the specified hlist?
+ * @n: Node to check for singularity.
+ * @h: Header for potentially singular list.
+ *
+ * Check whether the node is the only node of the head without
+ * accessing head, thus avoiding unnecessary cache misses.
+ */
+static inline bool
+hlist_is_singular_node(struct hlist_node *n, struct hlist_head *h)
 {
-	next->next = n->next;
-	n->next = next;
-	next->pprev = &n->next;
+	return !n->next && n->pprev == &h->first;
+}
 
-	if(next->next)
-		next->next->pprev  = &next->next;
+/**
+ * hlist_move_list - Move an hlist
+ * @old: hlist_head for old list.
+ * @new: hlist_head for new list.
+ *
+ * Move a list from one list head to another. Fixup the pprev
+ * reference of the first entry if it exists.
+ */
+static inline void hlist_move_list(struct hlist_head *old,
+				   struct hlist_head *new)
+{
+	new->first = old->first;
+	if (new->first)
+		new->first->pprev = &new->first;
+	old->first = NULL;
 }
 
 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
 
 #define hlist_for_each(pos, head) \
-	for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
-	     pos = pos->next)
+	for (pos = (head)->first; pos ; pos = pos->next)
 
 #define hlist_for_each_safe(pos, n, head) \
 	for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
 	     pos = n)
 
+#define hlist_entry_safe(ptr, type, member) \
+	({ typeof(ptr) ____ptr = (ptr); \
+	   ____ptr ? hlist_entry(____ptr, type, member) : NULL; \
+	})
+
 /**
  * hlist_for_each_entry	- iterate over list of given type
- * @tpos:	the type * to use as a loop cursor.
- * @pos:	the &struct hlist_node to use as a loop cursor.
+ * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
  * @member:	the name of the hlist_node within the struct.
  */
-#define hlist_for_each_entry(tpos, pos, head, member)			 \
-	for (pos = (head)->first;					 \
-	     pos && ({ prefetch(pos->next); 1;}) &&			 \
-		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
-	     pos = pos->next)
+#define hlist_for_each_entry(pos, head, member)				\
+	for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\
+	     pos;							\
+	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
 
 /**
  * hlist_for_each_entry_continue - iterate over a hlist continuing after current point
- * @tpos:	the type * to use as a loop cursor.
- * @pos:	the &struct hlist_node to use as a loop cursor.
+ * @pos:	the type * to use as a loop cursor.
  * @member:	the name of the hlist_node within the struct.
  */
-#define hlist_for_each_entry_continue(tpos, pos, member)		 \
-	for (pos = (pos)->next;						 \
-	     pos && ({ prefetch(pos->next); 1;}) &&			 \
-		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
-	     pos = pos->next)
+#define hlist_for_each_entry_continue(pos, member)			\
+	for (pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member);\
+	     pos;							\
+	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
 
 /**
  * hlist_for_each_entry_from - iterate over a hlist continuing from current point
- * @tpos:	the type * to use as a loop cursor.
- * @pos:	the &struct hlist_node to use as a loop cursor.
+ * @pos:	the type * to use as a loop cursor.
  * @member:	the name of the hlist_node within the struct.
  */
-#define hlist_for_each_entry_from(tpos, pos, member)			 \
-	for (; pos && ({ prefetch(pos->next); 1;}) &&			 \
-		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
-	     pos = pos->next)
+#define hlist_for_each_entry_from(pos, member)				\
+	for (; pos;							\
+	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member))
 
 /**
  * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
- * @tpos:	the type * to use as a loop cursor.
- * @pos:	the &struct hlist_node to use as a loop cursor.
- * @n:		another &struct hlist_node to use as temporary storage
+ * @pos:	the type * to use as a loop cursor.
+ * @n:		a &struct hlist_node to use as temporary storage
  * @head:	the head for your list.
  * @member:	the name of the hlist_node within the struct.
  */
-#define hlist_for_each_entry_safe(tpos, pos, n, head, member) 		 \
-	for (pos = (head)->first;					 \
-	     pos && ({ n = pos->next; 1; }) && 				 \
-		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
-	     pos = n)
+#define hlist_for_each_entry_safe(pos, n, head, member) 		\
+	for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\
+	     pos && ({ n = pos->member.next; 1; });			\
+	     pos = hlist_entry_safe(n, typeof(*pos), member))
 
 #endif
diff --git a/include/linux/poison.h b/include/linux/poison.h
new file mode 100644
index 0000000000..b92eb2f95b
--- /dev/null
+++ b/include/linux/poison.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_POISON_H
+#define _LINUX_POISON_H
+
+/********** include/linux/list.h **********/
+
+/*
+ * Architectures might want to move the poison pointer offset
+ * into some well-recognized area such as 0xdead000000000000,
+ * that is also not mappable by user-space exploits:
+ */
+#ifdef CONFIG_ILLEGAL_POINTER_VALUE
+# define POISON_POINTER_DELTA _AC(CONFIG_ILLEGAL_POINTER_VALUE, UL)
+#else
+# define POISON_POINTER_DELTA 0
+#endif
+
+/*
+ * These are non-NULL pointers that will result in page faults
+ * under normal circumstances, used to verify that nobody uses
+ * non-initialized list entries.
+ */
+#define LIST_POISON1  ((void *) 0x100 + POISON_POINTER_DELTA)
+#define LIST_POISON2  ((void *) 0x122 + POISON_POINTER_DELTA)
+
+#endif
diff --git a/include/linux/types.h b/include/linux/types.h
index c19d1dc053..fa7684e31e 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -206,4 +206,16 @@ struct ustat {
 	char			f_fpack[6];
 };
 
+struct list_head {
+	struct list_head *next, *prev;
+};
+
+struct hlist_head {
+	struct hlist_node *first;
+};
+
+struct hlist_node {
+	struct hlist_node *next, **pprev;
+};
+
 #endif /* _LINUX_TYPES_H */
diff --git a/lib/libfile.c b/lib/libfile.c
index b4d87b624a..863b6833a5 100644
--- a/lib/libfile.c
+++ b/lib/libfile.c
@@ -353,10 +353,6 @@ int copy_file(const char *src, const char *dst, int verbose)
 		goto out;
 	}
 
-	/* Set O_TRUNC only if file exist and is a regular file */
-	if (!s && S_ISREG(dststat.st_mode))
-		mode |= O_TRUNC;
-
 	dstfd = open(dst, mode);
 	if (dstfd < 0) {
 		printf("could not open %s: %s\n", dst, errno_str());
@@ -364,14 +360,25 @@ int copy_file(const char *src, const char *dst, int verbose)
 		goto out;
 	}
 
-	discard_range(dstfd, srcstat.st_size, 0);
+	ret = ftruncate(dstfd, 0);
+	if (ret)
+		goto out;
+
+	ret = stat(src, &srcstat);
+	if (ret)
+		goto out;
 
-	if (verbose) {
-		if (stat(src, &srcstat) < 0)
-			srcstat.st_size = 0;
+	if (srcstat.st_size != FILESIZE_MAX) {
+		discard_range(dstfd, srcstat.st_size, 0);
+		if (S_ISREG(dststat.st_mode)) {
+			ret = ftruncate(dstfd, srcstat.st_size);
+			if (ret)
+				goto out;
+		}
+	}
 
+	if (verbose)
 		init_progression_bar(srcstat.st_size);
-	}
 
 	while (1) {
 		r = read(srcfd, rw_buf, RW_BUF_SIZE);