Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull more set_fs removal from Al Viro:
"Christoph's 'use kernel_read and friends rather than open-coding
set_fs()' series"

* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: unexport vfs_readv and vfs_writev
fs: unexport vfs_read and vfs_write
fs: unexport __vfs_read/__vfs_write
lustre: switch to kernel_write
gadget/f_mass_storage: stop messing with the address limit
mconsole: switch to kernel_read
btrfs: switch write_buf to kernel_write
net/9p: switch p9_fd_read to kernel_write
mm/nommu: switch do_mmap_private to kernel_read
serial2002: switch serial2002_tty_write to kernel_{read/write}
fs: make the buf argument to __kernel_write a void pointer
fs: fix kernel_write prototype
fs: fix kernel_read prototype
fs: move kernel_read to fs/read_write.c
fs: move kernel_write to fs/read_write.c
autofs4: switch autofs4_write to __kernel_write
ashmem: switch to ->read_iter

arch/mips/kernel/elf.c

···
 	bool elf32;
 	u32 flags;
 	int ret;
+	loff_t pos;
 
 	elf32 = ehdr->e32.e_ident[EI_CLASS] == ELFCLASS32;
 	flags = elf32 ? ehdr->e32.e_flags : ehdr->e64.e_flags;
···
 
 		if (phdr32->p_filesz < sizeof(abiflags))
 			return -EINVAL;
-
-		ret = kernel_read(elf, phdr32->p_offset,
-				  (char *)&abiflags,
-				  sizeof(abiflags));
+		pos = phdr32->p_offset;
 	} else {
 		if (phdr64->p_type != PT_MIPS_ABIFLAGS)
 			return 0;
 		if (phdr64->p_filesz < sizeof(abiflags))
 			return -EINVAL;
-
-		ret = kernel_read(elf, phdr64->p_offset,
-				  (char *)&abiflags,
-				  sizeof(abiflags));
+		pos = phdr64->p_offset;
 	}
 
+	ret = kernel_read(elf, &abiflags, sizeof(abiflags), &pos);
 	if (ret < 0)
 		return ret;
 	if (ret != sizeof(abiflags))

arch/um/drivers/mconsole_kern.c

···
 	}
 
 	do {
-		loff_t pos = file->f_pos;
-		mm_segment_t old_fs = get_fs();
-		set_fs(KERNEL_DS);
-		len = vfs_read(file, buf, PAGE_SIZE - 1, &pos);
-		set_fs(old_fs);
-		file->f_pos = pos;
+		len = kernel_read(file, buf, PAGE_SIZE - 1, &file->f_pos);
 		if (len < 0) {
 			mconsole_reply(req, "Read of file failed", 1, 0);
 			goto out_free;

arch/x86/ia32/ia32_aout.c

···
 	unsigned long bss, start_addr, len, error;
 	int retval;
 	struct exec ex;
-
+	loff_t pos = 0;
 
 	retval = -ENOEXEC;
-	error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
+	error = kernel_read(file, &ex, sizeof(ex), &pos);
 	if (error != sizeof(ex))
 		goto out;
 

drivers/media/pci/cx25821/cx25821-audio-upstream.c

···
 		p = (char *)dev->_audiodata_buf_virt_addr + frame_offset;
 
 	for (i = 0; i < dev->_audio_lines_count; i++) {
-		int n = kernel_read(file, file_offset, mybuf, AUDIO_LINE_SIZE);
+		int n = kernel_read(file, mybuf, AUDIO_LINE_SIZE, &file_offset);
 		if (n < AUDIO_LINE_SIZE) {
 			pr_info("Done: exit %s() since no more bytes to read from Audio file\n",
 				__func__);
···
 			memcpy(p, mybuf, n);
 			p += n;
 		}
-		file_offset += n;
 	}
 	dev->_audioframe_count++;
 	fput(file);
···
 {
 	char *p = (void *)dev->_audiodata_buf_virt_addr;
 	struct file *file;
-	loff_t offset;
+	loff_t file_offset = 0;
 	int i, j;
 
 	file = filp_open(dev->_audiofilename, O_RDONLY | O_LARGEFILE, 0);
···
 		return PTR_ERR(file);
 	}
 
-	for (j = 0, offset = 0; j < NUM_AUDIO_FRAMES; j++) {
+	for (j = 0; j < NUM_AUDIO_FRAMES; j++) {
 		for (i = 0; i < dev->_audio_lines_count; i++) {
 			char buf[AUDIO_LINE_SIZE];
-			int n = kernel_read(file, offset, buf,
-						AUDIO_LINE_SIZE);
+			loff_t offset = file_offset;
+			int n = kernel_read(file, buf, AUDIO_LINE_SIZE, &file_offset);
 
 			if (n < AUDIO_LINE_SIZE) {
 				pr_info("Done: exit %s() since no more bytes to read from Audio file\n",
···
 
 			if (p)
 				memcpy(p + offset, buf, n);
-
-			offset += n;
 		}
 		dev->_audioframe_count++;
 	}

drivers/mtd/nand/nandsim.c

···
 	if (err)
 		return err;
 	noreclaim_flag = memalloc_noreclaim_save();
-	tx = kernel_read(file, pos, buf, count);
+	tx = kernel_read(file, buf, count, &pos);
 	memalloc_noreclaim_restore(noreclaim_flag);
 	put_pages(ns);
 	return tx;
···
 	if (err)
 		return err;
 	noreclaim_flag = memalloc_noreclaim_save();
-	tx = kernel_write(file, buf, count, pos);
+	tx = kernel_write(file, buf, count, &pos);
 	memalloc_noreclaim_restore(noreclaim_flag);
 	put_pages(ns);
 	return tx;

drivers/staging/android/ashmem.c

···
 	return 0;
 }
 
-/**
- * ashmem_read() - Reads a set of bytes from an Ashmem-enabled file
- * @file:	   The associated backing file.
- * @buf:	   The buffer of data being written to
- * @len:	   The number of bytes being read
- * @pos:	   The position of the first byte to read.
- *
- * Return: 0 if successful, or another return code if not.
- */
-static ssize_t ashmem_read(struct file *file, char __user *buf,
-			   size_t len, loff_t *pos)
+static ssize_t ashmem_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 {
-	struct ashmem_area *asma = file->private_data;
+	struct ashmem_area *asma = iocb->ki_filp->private_data;
 	int ret = 0;
 
 	mutex_lock(&ashmem_mutex);
···
 		goto out_unlock;
 	}
 
-	mutex_unlock(&ashmem_mutex);
-
 	/*
 	 * asma and asma->file are used outside the lock here.  We assume
 	 * once asma->file is set it will never be changed, and will not
 	 * be destroyed until all references to the file are dropped and
 	 * ashmem_release is called.
 	 */
-	ret = __vfs_read(asma->file, buf, len, pos);
-	if (ret >= 0)
-		/** Update backing file pos, since f_ops->read() doesn't */
-		asma->file->f_pos = *pos;
-	return ret;
-
+	mutex_unlock(&ashmem_mutex);
+	ret = vfs_iter_read(asma->file, iter, &iocb->ki_pos, 0);
+	mutex_lock(&ashmem_mutex);
+	if (ret > 0)
+		asma->file->f_pos = iocb->ki_pos;
 out_unlock:
 	mutex_unlock(&ashmem_mutex);
 	return ret;
···
 	.owner = THIS_MODULE,
 	.open = ashmem_open,
 	.release = ashmem_release,
-	.read = ashmem_read,
+	.read_iter = ashmem_read_iter,
 	.llseek = ashmem_llseek,
 	.mmap = ashmem_mmap,
 	.unlocked_ioctl = ashmem_ioctl,

drivers/staging/comedi/drivers/serial2002.c

···
 
 static int serial2002_tty_write(struct file *f, unsigned char *buf, int count)
 {
-	const char __user *p = (__force const char __user *)buf;
-	int result;
-	loff_t offset = 0;
-	mm_segment_t oldfs;
-
-	oldfs = get_fs();
-	set_fs(KERNEL_DS);
-	result = __vfs_write(f, p, count, &offset);
-	set_fs(oldfs);
-	return result;
+	loff_t pos = 0;
+	return kernel_write(f, buf, count, &pos);
 }
 
 static void serial2002_tty_read_poll_wait(struct file *f, int timeout)
···
 {
 	unsigned char ch;
 	int result;
+	loff_t pos = 0;
 
 	result = -1;
 	if (!IS_ERR(f)) {
-		mm_segment_t oldfs;
-		char __user *p = (__force char __user *)&ch;
-		loff_t offset = 0;
-
-		oldfs = get_fs();
-		set_fs(KERNEL_DS);
 		if (f->f_op->poll) {
 			serial2002_tty_read_poll_wait(f, timeout);
 
-			if (__vfs_read(f, p, 1, &offset) == 1)
+			if (kernel_read(f, &ch, 1, &pos) == 1)
 				result = ch;
 		} else {
 			/* Device does not support poll, busy wait */
···
 				if (retries >= timeout)
 					break;
 
-				if (__vfs_read(f, p, 1, &offset) == 1) {
+				if (kernel_read(f, &ch, 1, &pos) == 1) {
 					result = ch;
 					break;
 				}
 				usleep_range(100, 1000);
 			}
 		}
-		set_fs(oldfs);
 	}
 	return result;
 }

drivers/staging/lustre/lnet/libcfs/tracefile.c

···
 		__LASSERT_TAGE_INVARIANT(tage);
 
 		buf = kmap(tage->page);
-		rc = vfs_write(filp, (__force const char __user *)buf,
-			       tage->used, &filp->f_pos);
+		rc = kernel_write(filp, buf, tage->used, &filp->f_pos);
 		kunmap(tage->page);
 
 		if (rc != (int)tage->used) {
···
 	struct tracefiled_ctl *tctl = arg;
 	struct cfs_trace_page *tage;
 	struct cfs_trace_page *tmp;
-	mm_segment_t __oldfs;
 	struct file *filp;
 	char *buf;
 	int last_loop = 0;
···
 			__LASSERT(list_empty(&pc.pc_pages));
 			goto end_loop;
 		}
-		__oldfs = get_fs();
-		set_fs(get_ds());
 
 		list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
 			static loff_t f_pos;
···
 				f_pos = i_size_read(file_inode(filp));
 
 			buf = kmap(tage->page);
-			rc = vfs_write(filp, (__force const char __user *)buf,
-				       tage->used, &f_pos);
+			rc = kernel_write(filp, buf, tage->used, &f_pos);
 			kunmap(tage->page);
 
 			if (rc != (int)tage->used) {
···
 				break;
 			}
 		}
-		set_fs(__oldfs);
 
 		filp_close(filp, NULL);
 		put_pages_on_daemon_list(&pc);

drivers/staging/lustre/lustre/obdclass/kernelcomm.c

···
 	struct kuc_hdr *kuch = (struct kuc_hdr *)payload;
 	ssize_t count = kuch->kuc_msglen;
 	loff_t offset = 0;
-	mm_segment_t fs;
 	int rc = -ENXIO;
 
 	if (IS_ERR_OR_NULL(filp))
···
 		return rc;
 	}
 
-	fs = get_fs();
-	set_fs(KERNEL_DS);
 	while (count > 0) {
-		rc = vfs_write(filp, (void __force __user *)payload,
-			       count, &offset);
+		rc = kernel_write(filp, payload, count, &offset);
 		if (rc < 0)
 			break;
 		count -= rc;
 		payload += rc;
 		rc = 0;
 	}
-	set_fs(fs);
 
 	if (rc < 0)
 		CWARN("message send failed (%d)\n", rc);

drivers/target/target_core_alua.c

···
 	u32 md_buf_len)
 {
 	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
+	loff_t pos = 0;
 	int ret;
 
 	if (IS_ERR(file)) {
 		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
 		return -ENODEV;
 	}
-	ret = kernel_write(file, md_buf, md_buf_len, 0);
+	ret = kernel_write(file, md_buf, md_buf_len, &pos);
 	if (ret < 0)
 		pr_err("Error writing ALUA metadata file: %s\n", path);
 	fput(file);

drivers/target/target_core_file.c

···
 
 	for (prot = 0; prot < prot_length;) {
 		sector_t len = min_t(sector_t, bufsize, prot_length - prot);
-		ssize_t ret = kernel_write(prot_fd, buf, len, pos + prot);
+		ssize_t ret = kernel_write(prot_fd, buf, len, &pos);
 
 		if (ret != len) {
 			pr_err("vfs_write to prot file failed: %zd\n", ret);

drivers/target/target_core_pr.c

···
 	char path[512];
 	u32 pr_aptpl_buf_len;
 	int ret;
+	loff_t pos = 0;
 
 	memset(path, 0, 512);
 
···
 
 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
 
-	ret = kernel_write(file, buf, pr_aptpl_buf_len, 0);
+	ret = kernel_write(file, buf, pr_aptpl_buf_len, &pos);
 
 	if (ret < 0)
 		pr_debug("Error writing APTPL metadata file: %s\n", path);

drivers/usb/gadget/function/f_mass_storage.c

···
 
 		/* Perform the read */
 		file_offset_tmp = file_offset;
-		nread = vfs_read(curlun->filp,
-				 (char __user *)bh->buf,
-				 amount, &file_offset_tmp);
+		nread = kernel_read(curlun->filp, bh->buf, amount,
+				&file_offset_tmp);
 		VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
 		      (unsigned long long)file_offset, (int)nread);
 		if (signal_pending(current))
···
 
 		/* Perform the write */
 		file_offset_tmp = file_offset;
-		nwritten = vfs_write(curlun->filp, (char __user *)bh->buf,
-				amount, &file_offset_tmp);
+		nwritten = kernel_write(curlun->filp, bh->buf, amount,
+				&file_offset_tmp);
 		VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
 				(unsigned long long)file_offset, (int)nwritten);
 		if (signal_pending(current))
···
 
 		/* Perform the read */
 		file_offset_tmp = file_offset;
-		nread = vfs_read(curlun->filp,
-				(char __user *) bh->buf,
-				amount, &file_offset_tmp);
+		nread = kernel_read(curlun->filp, bh->buf, amount,
+				&file_offset_tmp);
 		VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
 				(unsigned long long) file_offset,
 				(int) nread);
···
 
 	/* Allow the thread to be frozen */
 	set_freezable();
-
-	/*
-	 * Arrange for userspace references to be interpreted as kernel
-	 * pointers.  That way we can pass a kernel pointer to a routine
-	 * that expects a __user pointer and it will work okay.
-	 */
-	set_fs(get_ds());
 
 	/* The main loop */
 	while (common->state != FSG_STATE_TERMINATED) {

fs/autofs4/waitq.c

···
 			 struct file *file, const void *addr, int bytes)
 {
 	unsigned long sigpipe, flags;
-	mm_segment_t fs;
 	const char *data = (const char *)addr;
 	ssize_t wr = 0;
 
 	sigpipe = sigismember(&current->pending.signal, SIGPIPE);
 
-	/* Save pointer to user space and point back to kernel space */
-	fs = get_fs();
-	set_fs(KERNEL_DS);
-
 	mutex_lock(&sbi->pipe_mutex);
 	while (bytes) {
-		wr = __vfs_write(file, data, bytes, &file->f_pos);
+		wr = __kernel_write(file, data, bytes, &file->f_pos);
 		if (wr <= 0)
 			break;
 		data += wr;
 		bytes -= wr;
 	}
 	mutex_unlock(&sbi->pipe_mutex);
-
-	set_fs(fs);
 
 	/* Keep the currently executing process from receiving a
 	 * SIGPIPE unless it was already supposed to get one

fs/binfmt_aout.c

···
 	unsigned long error;
 	int retval;
 	struct exec ex;
+	loff_t pos = 0;
 
 	inode = file_inode(file);
 
 	retval = -ENOEXEC;
-	error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
+	error = kernel_read(file, &ex, sizeof(ex), &pos);
 	if (error != sizeof(ex))
 		goto out;
 

fs/binfmt_elf.c

···
 {
 	struct elf_phdr *elf_phdata = NULL;
 	int retval, size, err = -1;
+	loff_t pos = elf_ex->e_phoff;
 
 	/*
 	 * If the size of this structure has changed, then punt, since
···
 		goto out;
 
 	/* Read in the program headers */
-	retval = kernel_read(elf_file, elf_ex->e_phoff,
-			     (char *)elf_phdata, size);
+	retval = kernel_read(elf_file, elf_phdata, size, &pos);
 	if (retval != size) {
 		err = (retval < 0) ? retval : -EIO;
 		goto out;
···
 		struct elfhdr interp_elf_ex;
 	} *loc;
 	struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE;
+	loff_t pos;
 
 	loc = kmalloc(sizeof(*loc), GFP_KERNEL);
 	if (!loc) {
···
 			if (!elf_interpreter)
 				goto out_free_ph;
 
-			retval = kernel_read(bprm->file, elf_ppnt->p_offset,
-					     elf_interpreter,
-					     elf_ppnt->p_filesz);
+			pos = elf_ppnt->p_offset;
+			retval = kernel_read(bprm->file, elf_interpreter,
+					     elf_ppnt->p_filesz, &pos);
 			if (retval != elf_ppnt->p_filesz) {
 				if (retval >= 0)
 					retval = -EIO;
···
 			would_dump(bprm, interpreter);
 
 			/* Get the exec headers */
-			retval = kernel_read(interpreter, 0,
-					     (void *)&loc->interp_elf_ex,
-					     sizeof(loc->interp_elf_ex));
+			pos = 0;
+			retval = kernel_read(interpreter, &loc->interp_elf_ex,
+					     sizeof(loc->interp_elf_ex), &pos);
 			if (retval != sizeof(loc->interp_elf_ex)) {
 				if (retval >= 0)
 					retval = -EIO;
···
 	unsigned long elf_bss, bss, len;
 	int retval, error, i, j;
 	struct elfhdr elf_ex;
+	loff_t pos = 0;
 
 	error = -ENOEXEC;
-	retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
+	retval = kernel_read(file, &elf_ex, sizeof(elf_ex), &pos);
 	if (retval != sizeof(elf_ex))
 		goto out;
 
···
 
 	eppnt = elf_phdata;
 	error = -ENOEXEC;
-	retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
+	pos =  elf_ex.e_phoff;
+	retval = kernel_read(file, eppnt, j, &pos);
 	if (retval != j)
 		goto out_free_ph;
 

fs/binfmt_elf_fdpic.c

···
 	struct elf32_phdr *phdr;
 	unsigned long size;
 	int retval, loop;
+	loff_t pos = params->hdr.e_phoff;
 
 	if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 		return -ENOMEM;
···
 	if (!params->phdrs)
 		return -ENOMEM;
 
-	retval = kernel_read(file, params->hdr.e_phoff,
-			     (char *) params->phdrs, size);
+	retval = kernel_read(file, params->phdrs, size, &pos);
 	if (unlikely(retval != size))
 		return retval < 0 ? retval : -ENOEXEC;
 
···
 	char *interpreter_name = NULL;
 	int executable_stack;
 	int retval, i;
+	loff_t pos;
 
 	kdebug("____ LOAD %d ____", current->pid);
 
···
 			if (!interpreter_name)
 				goto error;
 
-			retval = kernel_read(bprm->file,
-					     phdr->p_offset,
-					     interpreter_name,
-					     phdr->p_filesz);
+			pos = phdr->p_offset;
+			retval = kernel_read(bprm->file, interpreter_name,
+					     phdr->p_filesz, &pos);
 			if (unlikely(retval != phdr->p_filesz)) {
 				if (retval >= 0)
 					retval = -ENOEXEC;
···
 			 */
 			would_dump(bprm, interpreter);
 
-			retval = kernel_read(interpreter, 0, bprm->buf,
-					     BINPRM_BUF_SIZE);
+			pos = 0;
+			retval = kernel_read(interpreter, bprm->buf,
+					BINPRM_BUF_SIZE, &pos);
 			if (unlikely(retval != BINPRM_BUF_SIZE)) {
 				if (retval >= 0)
 					retval = -ENOEXEC;

fs/binfmt_flat.c

···
 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 
-static int decompress_exec(
-	struct linux_binprm *bprm,
-	unsigned long offset,
-	char *dst,
-	long len,
-	int fd)
+static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst,
+		long len, int fd)
 {
 	unsigned char *buf;
 	z_stream strm;
-	loff_t fpos;
 	int ret, retval;
 
-	pr_debug("decompress_exec(offset=%lx,buf=%p,len=%lx)\n", offset, dst, len);
+	pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
 
 	memset(&strm, 0, sizeof(strm));
 	strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
···
 	}
 
 	/* Read in first chunk of data and parse gzip header. */
-	fpos = offset;
-	ret = kernel_read(bprm->file, offset, buf, LBUFSIZE);
+	ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
 
 	strm.next_in = buf;
 	strm.avail_in = ret;
 	strm.total_in = 0;
-	fpos += ret;
 
 	retval = -ENOEXEC;
 
···
 	}
 
 	while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
-		ret = kernel_read(bprm->file, fpos, buf, LBUFSIZE);
+		ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
 		if (ret <= 0)
 			break;
 		len -= ret;
···
 		strm.next_in = buf;
 		strm.avail_in = ret;
 		strm.total_in = 0;
-		fpos += ret;
 	}
 
 	if (ret < 0) {

fs/binfmt_misc.c

···
 
 	bprm->file = interp_file;
 	if (fmt->flags & MISC_FMT_CREDENTIALS) {
+		loff_t pos = 0;
+
 		/*
 		 * No need to call prepare_binprm(), it's already been
 		 * done.  bprm->buf is stale, update from interp_file.
 		 */
 		memset(bprm->buf, 0, BINPRM_BUF_SIZE);
-		retval = kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE);
+		retval = kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE,
+				&pos);
 	} else
 		retval = prepare_binprm(bprm);
 

fs/btrfs/send.c

···
 static int write_buf(struct file *filp, const void *buf, u32 len, loff_t *off)
 {
 	int ret;
-	mm_segment_t old_fs;
 	u32 pos = 0;
 
-	old_fs = get_fs();
-	set_fs(KERNEL_DS);
-
 	while (pos < len) {
-		ret = vfs_write(filp, (__force const char __user *)buf + pos,
-				len - pos, off);
+		ret = kernel_write(filp, buf + pos, len - pos, off);
 		/* TODO handle that correctly */
 		/*if (ret == -ERESTARTSYS) {
 			continue;
 		}*/
 		if (ret < 0)
-			goto out;
+			return ret;
 		if (ret == 0) {
-			ret = -EIO;
-			goto out;
+			return -EIO;
 		}
 		pos += ret;
 	}
 
-	ret = 0;
-
-out:
-	set_fs(old_fs);
-	return ret;
+	return 0;
 }
 
 static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)

fs/coda/dir.c

···
 		goto out;
 
 	while (1) {
+		loff_t pos = ctx->pos - 2;
+
 		/* read entries from the directory file */
-		ret = kernel_read(host_file, ctx->pos - 2, (char *)vdir,
-				  sizeof(*vdir));
+		ret = kernel_read(host_file, vdir, sizeof(*vdir), &pos);
 		if (ret < 0) {
 			pr_err("%s: read dir %s failed %d\n",
 			       __func__, coda_f2s(&cii->c_fid), ret);

fs/ecryptfs/read_write.c

···
 	lower_file = ecryptfs_inode_to_private(ecryptfs_inode)->lower_file;
 	if (!lower_file)
 		return -EIO;
-	rc = kernel_write(lower_file, data, size, offset);
+	rc = kernel_write(lower_file, data, size, &offset);
 	mark_inode_dirty_sync(ecryptfs_inode);
 	return rc;
 }
···
 	lower_file = ecryptfs_inode_to_private(ecryptfs_inode)->lower_file;
 	if (!lower_file)
 		return -EIO;
-	return kernel_read(lower_file, offset, data, size);
+	return kernel_read(lower_file, data, size, &offset);
 }
 
 /**

fs/exec.c

···
 }
 EXPORT_SYMBOL(open_exec);
 
-int kernel_read(struct file *file, loff_t offset,
-		char *addr, unsigned long count)
-{
-	mm_segment_t old_fs;
-	loff_t pos = offset;
-	int result;
-
-	old_fs = get_fs();
-	set_fs(get_ds());
-	/* The cast to a user pointer is valid due to the set_fs() */
-	result = vfs_read(file, (void __user *)addr, count, &pos);
-	set_fs(old_fs);
-	return result;
-}
-
-EXPORT_SYMBOL(kernel_read);
-
 int kernel_read_file(struct file *file, void **buf, loff_t *size,
 		     loff_t max_size, enum kernel_read_file_id id)
 {
···
 
 	pos = 0;
 	while (pos < i_size) {
-		bytes = kernel_read(file, pos, (char *)(*buf) + pos,
-				    i_size - pos);
+		bytes = kernel_read(file, *buf + pos, i_size - pos, &pos);
 		if (bytes < 0) {
 			ret = bytes;
 			goto out;
···
 
 		if (bytes == 0)
 			break;
-		pos += bytes;
 	}
 
 	if (pos != i_size) {
···
 int prepare_binprm(struct linux_binprm *bprm)
 {
 	int retval;
+	loff_t pos = 0;
 
 	bprm_fill_uid(bprm);
 
···
 	bprm->called_set_creds = 1;
 
 	memset(bprm->buf, 0, BINPRM_BUF_SIZE);
-	return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE);
+	return kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, &pos);
 }
 
 EXPORT_SYMBOL(prepare_binprm);

fs/read_write.c

···
 	else
 		return -EINVAL;
 }
-EXPORT_SYMBOL(__vfs_read);
+
+ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
+{
+	mm_segment_t old_fs;
+	ssize_t result;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	/* The cast to a user pointer is valid due to the set_fs() */
+	result = vfs_read(file, (void __user *)buf, count, pos);
+	set_fs(old_fs);
+	return result;
+}
+EXPORT_SYMBOL(kernel_read);
 
 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 {
···
 
 	return ret;
 }
-
-EXPORT_SYMBOL(vfs_read);
 
 static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
 {
···
 	else
 		return -EINVAL;
 }
-EXPORT_SYMBOL(__vfs_write);
 
-ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
+ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
 {
 	mm_segment_t old_fs;
 	const char __user *p;
···
 	inc_syscw(current);
 	return ret;
 }
-
 EXPORT_SYMBOL(__kernel_write);
+
+ssize_t kernel_write(struct file *file, const void *buf, size_t count,
+			    loff_t *pos)
+{
+	mm_segment_t old_fs;
+	ssize_t res;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	/* The cast to a user pointer is valid due to the set_fs() */
+	res = vfs_write(file, (__force const char __user *)buf, count, pos);
+	set_fs(old_fs);
+
+	return res;
+}
+EXPORT_SYMBOL(kernel_write);
 
 ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
 {
···
 
 	return ret;
 }
-
-EXPORT_SYMBOL(vfs_write);
 
 static inline loff_t file_pos_read(struct file *file)
 {
···
 
 	return ret;
 }
-EXPORT_SYMBOL(vfs_readv);
 
-ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
+static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 		   unsigned long vlen, loff_t *pos, rwf_t flags)
 {
 	struct iovec iovstack[UIO_FASTIOV];
···
 	}
 	return ret;
 }
-EXPORT_SYMBOL(vfs_writev);
 
 static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
 			unsigned long vlen, rwf_t flags)

fs/splice.c

···
 	return res;
 }
 
-ssize_t kernel_write(struct file *file, const char *buf, size_t count,
-			    loff_t pos)
-{
-	mm_segment_t old_fs;
-	ssize_t res;
-
-	old_fs = get_fs();
-	set_fs(get_ds());
-	/* The cast to a user pointer is valid due to the set_fs() */
-	res = vfs_write(file, (__force const char __user *)buf, count, &pos);
-	set_fs(old_fs);
-
-	return res;
-}
-EXPORT_SYMBOL(kernel_write);
-
 static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 				 struct pipe_inode_info *pipe, size_t len,
 				 unsigned int flags)

include/linux/fs.h

···
 			      struct iovec **ret_pointer);
 
 extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *);
-extern ssize_t __vfs_write(struct file *, const char __user *, size_t, loff_t *);
 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
 extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
-		unsigned long, loff_t *, rwf_t);
-extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
 		unsigned long, loff_t *, rwf_t);
 extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
 				   loff_t, size_t, unsigned int);
···
 	return kernel_read_file_str[id];
 }
 
-extern int kernel_read(struct file *, loff_t, char *, unsigned long);
 extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
 			    enum kernel_read_file_id);
 extern int kernel_read_file_from_path(char *, void **, loff_t *, loff_t,
 				      enum kernel_read_file_id);
 extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,
 				    enum kernel_read_file_id);
-extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
-extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
+extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);
+extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *);
+extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *);
 extern struct file * open_exec(const char *);
  
 /* fs/dcache.c -- generic fs support functions */

kernel/acct.c

···
 	if (file_start_write_trylock(file)) {
 		/* it's been opened O_APPEND, so position is irrelevant */
 		loff_t pos = 0;
-		__kernel_write(file, (char *)&ac, sizeof(acct_t), &pos);
+		__kernel_write(file, &ac, sizeof(acct_t), &pos);
 		file_end_write(file);
 	}
 out:

kernel/sysctl_binary.c

···
 		size_t length = oldlen / sizeof(*vec);
 		char *str, *end;
 		int i;
+		loff_t pos = 0;
 
-		result = kernel_read(file, 0, buffer, BUFSZ - 1);
+		result = kernel_read(file, buffer, BUFSZ - 1, &pos);
 		if (result < 0)
 			goto out_kfree;
 
···
 		size_t length = newlen / sizeof(*vec);
 		char *str, *end;
 		int i;
+		loff_t pos = 0;
 
 		str = buffer;
 		end = str + BUFSZ;
···
 			str += scnprintf(str, end - str, "%lu\t", value);
 		}
 
-		result = kernel_write(file, buffer, str - buffer, 0);
+		result = kernel_write(file, buffer, str - buffer, &pos);
 		if (result < 0)
 			goto out_kfree;
 	}
···
 		size_t length = oldlen / sizeof(*vec);
 		char *str, *end;
 		int i;
+		loff_t pos = 0;
 
-		result = kernel_read(file, 0, buffer, BUFSZ - 1);
+		result = kernel_read(file, buffer, BUFSZ - 1, &pos);
 		if (result < 0)
 			goto out_kfree;
 
···
 		size_t length = newlen / sizeof(*vec);
 		char *str, *end;
 		int i;
+		loff_t pos = 0;
 
 		str = buffer;
 		end = str + BUFSZ;
···
 			str += scnprintf(str, end - str, "%lu\t", value);
 		}
 
-		result = kernel_write(file, buffer, str - buffer, 0);
+		result = kernel_write(file, buffer, str - buffer, &pos);
 		if (result < 0)
 			goto out_kfree;
 	}
···
 	if (oldval && oldlen) {
 		char buf[UUID_STRING_LEN + 1];
 		uuid_t uuid;
+		loff_t pos = 0;
 
-		result = kernel_read(file, 0, buf, sizeof(buf) - 1);
+		result = kernel_read(file, buf, sizeof(buf) - 1, &pos);
 		if (result < 0)
 			goto out;
 
···
 		char buf[15], *nodep;
 		unsigned long area, node;
 		__le16 dnaddr;
+		loff_t pos = 0;
 
-		result = kernel_read(file, 0, buf, sizeof(buf) - 1);
+		result = kernel_read(file, buf, sizeof(buf) - 1, &pos);
 		if (result < 0)
 			goto out;
 
···
 		__le16 dnaddr;
 		char buf[15];
 		int len;
+		loff_t pos = 0;
 
 		result = -EINVAL;
 		if (newlen != sizeof(dnaddr))
···
 				le16_to_cpu(dnaddr) >> 10,
 				le16_to_cpu(dnaddr) & 0x3ff);
 
-		result = kernel_write(file, buf, len, 0);
+		result = kernel_write(file, buf, len, &pos);
 		if (result < 0)
 			goto out;
 	}

mm/nommu.c

···
 
 	if (vma->vm_file) {
 		/* read the contents of a file into the copy */
-		mm_segment_t old_fs;
 		loff_t fpos;
 
 		fpos = vma->vm_pgoff;
 		fpos <<= PAGE_SHIFT;
 
-		old_fs = get_fs();
-		set_fs(KERNEL_DS);
-		ret = __vfs_read(vma->vm_file, base, len, &fpos);
-		set_fs(old_fs);
-
+		ret = kernel_read(vma->vm_file, base, len, &fpos);
 		if (ret < 0)
 			goto error_free;
 

net/9p/trans_fd.c

···
 {
 	int ret;
 	struct p9_trans_fd *ts = NULL;
+	loff_t pos;
 
 	if (client && client->status != Disconnected)
 		ts = client->trans;
···
 	if (!(ts->rd->f_flags & O_NONBLOCK))
 		p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
 
-	ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
+	pos = ts->rd->f_pos;
+	ret = kernel_read(ts->rd, v, len, &pos);
 	if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 		client->status = Disconnected;
 	return ret;
···
 
 static int p9_fd_write(struct p9_client *client, void *v, int len)
 {
-	int ret;
-	mm_segment_t oldfs;
+	ssize_t ret;
 	struct p9_trans_fd *ts = NULL;
 
 	if (client && client->status != Disconnected)
···
 	if (!(ts->wr->f_flags & O_NONBLOCK))
 		p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
 
-	oldfs = get_fs();
-	set_fs(get_ds());
-	/* The cast to a user pointer is valid due to the set_fs() */
-	ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
-	set_fs(oldfs);
-
+	ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
 	if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 		client->status = Disconnected;
 	return ret;

security/keys/big_key.c

···
 		 * File content is stored encrypted with randomly generated key.
 		 */
 		size_t enclen = ALIGN(datalen, crypto_skcipher_blocksize(big_key_skcipher));
+		loff_t pos = 0;
 
 		/* prepare aligned data to encrypt */
 		data = kmalloc(enclen, GFP_KERNEL);
···
 			goto err_enckey;
 		}
 
-		written = kernel_write(file, data, enclen, 0);
+		written = kernel_write(file, data, enclen, &pos);
 		if (written != enclen) {
 			ret = written;
 			if (written >= 0)
···
 		u8 *data;
 		u8 *enckey = (u8 *)key->payload.data[big_key_data];
 		size_t enclen = ALIGN(datalen, crypto_skcipher_blocksize(big_key_skcipher));
+		loff_t pos = 0;
 
 		data = kmalloc(enclen, GFP_KERNEL);
 		if (!data)
···
 		}
 
 		/* read file to kernel and decrypt */
-		ret = kernel_read(file, 0, data, enclen);
+		ret = kernel_read(file, data, enclen, &pos);
 		if (ret >= 0 && ret != enclen) {
 			ret = -EIO;
 			goto err_fput;