mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 01:41:39 +00:00
![Al Viro](/assets/img/avatar_default.png)
no point going through the intermediate pipe Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1693 lines
39 KiB
C
1693 lines
39 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* linux/fs/read_write.c
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*/
|
|
|
|
#include <linux/slab.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/sched/xacct.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/file.h>
|
|
#include <linux/uio.h>
|
|
#include <linux/fsnotify.h>
|
|
#include <linux/security.h>
|
|
#include <linux/export.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/splice.h>
|
|
#include <linux/compat.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/fs.h>
|
|
#include "internal.h"
|
|
|
|
#include <linux/uaccess.h>
|
|
#include <asm/unistd.h>
|
|
|
|
const struct file_operations generic_ro_fops = {
|
|
.llseek = generic_file_llseek,
|
|
.read_iter = generic_file_read_iter,
|
|
.mmap = generic_file_readonly_mmap,
|
|
.splice_read = generic_file_splice_read,
|
|
};
|
|
|
|
EXPORT_SYMBOL(generic_ro_fops);
|
|
|
|
static inline bool unsigned_offsets(struct file *file)
|
|
{
|
|
return file->f_mode & FMODE_UNSIGNED_OFFSET;
|
|
}
|
|
|
|
/**
|
|
* vfs_setpos - update the file offset for lseek
|
|
* @file: file structure in question
|
|
* @offset: file offset to seek to
|
|
* @maxsize: maximum file size
|
|
*
|
|
* This is a low-level filesystem helper for updating the file offset to
|
|
* the value specified by @offset if the given offset is valid and it is
|
|
* not equal to the current file offset.
|
|
*
|
|
* Return the specified offset on success and -EINVAL on invalid offset.
|
|
*/
|
|
loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)
|
|
{
|
|
if (offset < 0 && !unsigned_offsets(file))
|
|
return -EINVAL;
|
|
if (offset > maxsize)
|
|
return -EINVAL;
|
|
|
|
if (offset != file->f_pos) {
|
|
file->f_pos = offset;
|
|
file->f_version = 0;
|
|
}
|
|
return offset;
|
|
}
|
|
EXPORT_SYMBOL(vfs_setpos);
|
|
|
|
/**
|
|
* generic_file_llseek_size - generic llseek implementation for regular files
|
|
* @file: file structure to seek on
|
|
* @offset: file offset to seek to
|
|
* @whence: type of seek
|
|
* @size: max size of this file in file system
|
|
* @eof: offset used for SEEK_END position
|
|
*
|
|
* This is a variant of generic_file_llseek that allows passing in a custom
|
|
* maximum file size and a custom EOF position, for e.g. hashed directories
|
|
*
|
|
* Synchronization:
|
|
* SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms)
|
|
* SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes.
|
|
* read/writes behave like SEEK_SET against seeks.
|
|
*/
|
|
loff_t
|
|
generic_file_llseek_size(struct file *file, loff_t offset, int whence,
|
|
loff_t maxsize, loff_t eof)
|
|
{
|
|
switch (whence) {
|
|
case SEEK_END:
|
|
offset += eof;
|
|
break;
|
|
case SEEK_CUR:
|
|
/*
|
|
* Here we special-case the lseek(fd, 0, SEEK_CUR)
|
|
* position-querying operation. Avoid rewriting the "same"
|
|
* f_pos value back to the file because a concurrent read(),
|
|
* write() or lseek() might have altered it
|
|
*/
|
|
if (offset == 0)
|
|
return file->f_pos;
|
|
/*
|
|
* f_lock protects against read/modify/write race with other
|
|
* SEEK_CURs. Note that parallel writes and reads behave
|
|
* like SEEK_SET.
|
|
*/
|
|
spin_lock(&file->f_lock);
|
|
offset = vfs_setpos(file, file->f_pos + offset, maxsize);
|
|
spin_unlock(&file->f_lock);
|
|
return offset;
|
|
case SEEK_DATA:
|
|
/*
|
|
* In the generic case the entire file is data, so as long as
|
|
* offset isn't at the end of the file then the offset is data.
|
|
*/
|
|
if ((unsigned long long)offset >= eof)
|
|
return -ENXIO;
|
|
break;
|
|
case SEEK_HOLE:
|
|
/*
|
|
* There is a virtual hole at the end of the file, so as long as
|
|
* offset isn't i_size or larger, return i_size.
|
|
*/
|
|
if ((unsigned long long)offset >= eof)
|
|
return -ENXIO;
|
|
offset = eof;
|
|
break;
|
|
}
|
|
|
|
return vfs_setpos(file, offset, maxsize);
|
|
}
|
|
EXPORT_SYMBOL(generic_file_llseek_size);
|
|
|
|
/**
|
|
* generic_file_llseek - generic llseek implementation for regular files
|
|
* @file: file structure to seek on
|
|
* @offset: file offset to seek to
|
|
* @whence: type of seek
|
|
*
|
|
* This is a generic implemenation of ->llseek useable for all normal local
|
|
* filesystems. It just updates the file offset to the value specified by
|
|
* @offset and @whence.
|
|
*/
|
|
loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
|
|
return generic_file_llseek_size(file, offset, whence,
|
|
inode->i_sb->s_maxbytes,
|
|
i_size_read(inode));
|
|
}
|
|
EXPORT_SYMBOL(generic_file_llseek);
|
|
|
|
/**
|
|
* fixed_size_llseek - llseek implementation for fixed-sized devices
|
|
* @file: file structure to seek on
|
|
* @offset: file offset to seek to
|
|
* @whence: type of seek
|
|
* @size: size of the file
|
|
*
|
|
*/
|
|
loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)
|
|
{
|
|
switch (whence) {
|
|
case SEEK_SET: case SEEK_CUR: case SEEK_END:
|
|
return generic_file_llseek_size(file, offset, whence,
|
|
size, size);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(fixed_size_llseek);
|
|
|
|
/**
|
|
* no_seek_end_llseek - llseek implementation for fixed-sized devices
|
|
* @file: file structure to seek on
|
|
* @offset: file offset to seek to
|
|
* @whence: type of seek
|
|
*
|
|
*/
|
|
loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
switch (whence) {
|
|
case SEEK_SET: case SEEK_CUR:
|
|
return generic_file_llseek_size(file, offset, whence,
|
|
OFFSET_MAX, 0);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(no_seek_end_llseek);
|
|
|
|
/**
|
|
* no_seek_end_llseek_size - llseek implementation for fixed-sized devices
|
|
* @file: file structure to seek on
|
|
* @offset: file offset to seek to
|
|
* @whence: type of seek
|
|
* @size: maximal offset allowed
|
|
*
|
|
*/
|
|
loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size)
|
|
{
|
|
switch (whence) {
|
|
case SEEK_SET: case SEEK_CUR:
|
|
return generic_file_llseek_size(file, offset, whence,
|
|
size, 0);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(no_seek_end_llseek_size);
|
|
|
|
/**
|
|
* noop_llseek - No Operation Performed llseek implementation
|
|
* @file: file structure to seek on
|
|
* @offset: file offset to seek to
|
|
* @whence: type of seek
|
|
*
|
|
* This is an implementation of ->llseek useable for the rare special case when
|
|
* userspace expects the seek to succeed but the (device) file is actually not
|
|
* able to perform the seek. In this case you use noop_llseek() instead of
|
|
* falling back to the default implementation of ->llseek.
|
|
*/
|
|
loff_t noop_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
return file->f_pos;
|
|
}
|
|
EXPORT_SYMBOL(noop_llseek);
|
|
|
|
loff_t no_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
return -ESPIPE;
|
|
}
|
|
EXPORT_SYMBOL(no_llseek);
|
|
|
|
loff_t default_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
loff_t retval;
|
|
|
|
inode_lock(inode);
|
|
switch (whence) {
|
|
case SEEK_END:
|
|
offset += i_size_read(inode);
|
|
break;
|
|
case SEEK_CUR:
|
|
if (offset == 0) {
|
|
retval = file->f_pos;
|
|
goto out;
|
|
}
|
|
offset += file->f_pos;
|
|
break;
|
|
case SEEK_DATA:
|
|
/*
|
|
* In the generic case the entire file is data, so as
|
|
* long as offset isn't at the end of the file then the
|
|
* offset is data.
|
|
*/
|
|
if (offset >= inode->i_size) {
|
|
retval = -ENXIO;
|
|
goto out;
|
|
}
|
|
break;
|
|
case SEEK_HOLE:
|
|
/*
|
|
* There is a virtual hole at the end of the file, so
|
|
* as long as offset isn't i_size or larger, return
|
|
* i_size.
|
|
*/
|
|
if (offset >= inode->i_size) {
|
|
retval = -ENXIO;
|
|
goto out;
|
|
}
|
|
offset = inode->i_size;
|
|
break;
|
|
}
|
|
retval = -EINVAL;
|
|
if (offset >= 0 || unsigned_offsets(file)) {
|
|
if (offset != file->f_pos) {
|
|
file->f_pos = offset;
|
|
file->f_version = 0;
|
|
}
|
|
retval = offset;
|
|
}
|
|
out:
|
|
inode_unlock(inode);
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL(default_llseek);
|
|
|
|
loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
loff_t (*fn)(struct file *, loff_t, int);
|
|
|
|
fn = no_llseek;
|
|
if (file->f_mode & FMODE_LSEEK) {
|
|
if (file->f_op->llseek)
|
|
fn = file->f_op->llseek;
|
|
}
|
|
return fn(file, offset, whence);
|
|
}
|
|
EXPORT_SYMBOL(vfs_llseek);
|
|
|
|
static off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence)
|
|
{
|
|
off_t retval;
|
|
struct fd f = fdget_pos(fd);
|
|
if (!f.file)
|
|
return -EBADF;
|
|
|
|
retval = -EINVAL;
|
|
if (whence <= SEEK_MAX) {
|
|
loff_t res = vfs_llseek(f.file, offset, whence);
|
|
retval = res;
|
|
if (res != (loff_t)retval)
|
|
retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */
|
|
}
|
|
fdput_pos(f);
|
|
return retval;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
|
|
{
|
|
return ksys_lseek(fd, offset, whence);
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
|
|
{
|
|
return ksys_lseek(fd, offset, whence);
|
|
}
|
|
#endif
|
|
|
|
#if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT) || \
|
|
defined(__ARCH_WANT_SYS_LLSEEK)
|
|
SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
|
|
unsigned long, offset_low, loff_t __user *, result,
|
|
unsigned int, whence)
|
|
{
|
|
int retval;
|
|
struct fd f = fdget_pos(fd);
|
|
loff_t offset;
|
|
|
|
if (!f.file)
|
|
return -EBADF;
|
|
|
|
retval = -EINVAL;
|
|
if (whence > SEEK_MAX)
|
|
goto out_putf;
|
|
|
|
offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
|
|
whence);
|
|
|
|
retval = (int)offset;
|
|
if (offset >= 0) {
|
|
retval = -EFAULT;
|
|
if (!copy_to_user(result, &offset, sizeof(offset)))
|
|
retval = 0;
|
|
}
|
|
out_putf:
|
|
fdput_pos(f);
|
|
return retval;
|
|
}
|
|
#endif
|
|
|
|
int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
|
|
{
|
|
struct inode *inode;
|
|
int retval = -EINVAL;
|
|
|
|
inode = file_inode(file);
|
|
if (unlikely((ssize_t) count < 0))
|
|
return retval;
|
|
|
|
/*
|
|
* ranged mandatory locking does not apply to streams - it makes sense
|
|
* only for files where position has a meaning.
|
|
*/
|
|
if (ppos) {
|
|
loff_t pos = *ppos;
|
|
|
|
if (unlikely(pos < 0)) {
|
|
if (!unsigned_offsets(file))
|
|
return retval;
|
|
if (count >= -pos) /* both values are in 0..LLONG_MAX */
|
|
return -EOVERFLOW;
|
|
} else if (unlikely((loff_t) (pos + count) < 0)) {
|
|
if (!unsigned_offsets(file))
|
|
return retval;
|
|
}
|
|
|
|
if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
|
|
retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
|
|
read_write == READ ? F_RDLCK : F_WRLCK);
|
|
if (retval < 0)
|
|
return retval;
|
|
}
|
|
}
|
|
|
|
return security_file_permission(file,
|
|
read_write == READ ? MAY_READ : MAY_WRITE);
|
|
}
|
|
|
|
static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
|
|
{
|
|
struct iovec iov = { .iov_base = buf, .iov_len = len };
|
|
struct kiocb kiocb;
|
|
struct iov_iter iter;
|
|
ssize_t ret;
|
|
|
|
init_sync_kiocb(&kiocb, filp);
|
|
kiocb.ki_pos = (ppos ? *ppos : 0);
|
|
iov_iter_init(&iter, READ, &iov, 1, len);
|
|
|
|
ret = call_read_iter(filp, &kiocb, &iter);
|
|
BUG_ON(ret == -EIOCBQUEUED);
|
|
if (ppos)
|
|
*ppos = kiocb.ki_pos;
|
|
return ret;
|
|
}
|
|
|
|
static int warn_unsupported(struct file *file, const char *op)
|
|
{
|
|
pr_warn_ratelimited(
|
|
"kernel %s not supported for file %pD4 (pid: %d comm: %.20s)\n",
|
|
op, file, current->pid, current->comm);
|
|
return -EINVAL;
|
|
}
|
|
|
|
ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
|
|
{
|
|
struct kvec iov = {
|
|
.iov_base = buf,
|
|
.iov_len = min_t(size_t, count, MAX_RW_COUNT),
|
|
};
|
|
struct kiocb kiocb;
|
|
struct iov_iter iter;
|
|
ssize_t ret;
|
|
|
|
if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ)))
|
|
return -EINVAL;
|
|
if (!(file->f_mode & FMODE_CAN_READ))
|
|
return -EINVAL;
|
|
/*
|
|
* Also fail if ->read_iter and ->read are both wired up as that
|
|
* implies very convoluted semantics.
|
|
*/
|
|
if (unlikely(!file->f_op->read_iter || file->f_op->read))
|
|
return warn_unsupported(file, "read");
|
|
|
|
init_sync_kiocb(&kiocb, file);
|
|
kiocb.ki_pos = pos ? *pos : 0;
|
|
iov_iter_kvec(&iter, READ, &iov, 1, iov.iov_len);
|
|
ret = file->f_op->read_iter(&kiocb, &iter);
|
|
if (ret > 0) {
|
|
if (pos)
|
|
*pos = kiocb.ki_pos;
|
|
fsnotify_access(file);
|
|
add_rchar(current, ret);
|
|
}
|
|
inc_syscr(current);
|
|
return ret;
|
|
}
|
|
|
|
ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
|
|
{
|
|
ssize_t ret;
|
|
|
|
ret = rw_verify_area(READ, file, pos, count);
|
|
if (ret)
|
|
return ret;
|
|
return __kernel_read(file, buf, count, pos);
|
|
}
|
|
EXPORT_SYMBOL(kernel_read);
|
|
|
|
ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
|
|
{
|
|
ssize_t ret;
|
|
|
|
if (!(file->f_mode & FMODE_READ))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_READ))
|
|
return -EINVAL;
|
|
if (unlikely(!access_ok(buf, count)))
|
|
return -EFAULT;
|
|
|
|
ret = rw_verify_area(READ, file, pos, count);
|
|
if (ret)
|
|
return ret;
|
|
if (count > MAX_RW_COUNT)
|
|
count = MAX_RW_COUNT;
|
|
|
|
if (file->f_op->read)
|
|
ret = file->f_op->read(file, buf, count, pos);
|
|
else if (file->f_op->read_iter)
|
|
ret = new_sync_read(file, buf, count, pos);
|
|
else
|
|
ret = -EINVAL;
|
|
if (ret > 0) {
|
|
fsnotify_access(file);
|
|
add_rchar(current, ret);
|
|
}
|
|
inc_syscr(current);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
|
|
{
|
|
struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
|
|
struct kiocb kiocb;
|
|
struct iov_iter iter;
|
|
ssize_t ret;
|
|
|
|
init_sync_kiocb(&kiocb, filp);
|
|
kiocb.ki_pos = (ppos ? *ppos : 0);
|
|
iov_iter_init(&iter, WRITE, &iov, 1, len);
|
|
|
|
ret = call_write_iter(filp, &kiocb, &iter);
|
|
BUG_ON(ret == -EIOCBQUEUED);
|
|
if (ret > 0 && ppos)
|
|
*ppos = kiocb.ki_pos;
|
|
return ret;
|
|
}
|
|
|
|
/* caller is responsible for file_start_write/file_end_write */
|
|
ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
|
|
{
|
|
struct kvec iov = {
|
|
.iov_base = (void *)buf,
|
|
.iov_len = min_t(size_t, count, MAX_RW_COUNT),
|
|
};
|
|
struct kiocb kiocb;
|
|
struct iov_iter iter;
|
|
ssize_t ret;
|
|
|
|
if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE)))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_WRITE))
|
|
return -EINVAL;
|
|
/*
|
|
* Also fail if ->write_iter and ->write are both wired up as that
|
|
* implies very convoluted semantics.
|
|
*/
|
|
if (unlikely(!file->f_op->write_iter || file->f_op->write))
|
|
return warn_unsupported(file, "write");
|
|
|
|
init_sync_kiocb(&kiocb, file);
|
|
kiocb.ki_pos = pos ? *pos : 0;
|
|
iov_iter_kvec(&iter, WRITE, &iov, 1, iov.iov_len);
|
|
ret = file->f_op->write_iter(&kiocb, &iter);
|
|
if (ret > 0) {
|
|
if (pos)
|
|
*pos = kiocb.ki_pos;
|
|
fsnotify_modify(file);
|
|
add_wchar(current, ret);
|
|
}
|
|
inc_syscw(current);
|
|
return ret;
|
|
}
|
|
/*
|
|
* This "EXPORT_SYMBOL_GPL()" is more of a "EXPORT_SYMBOL_DONTUSE()",
|
|
* but autofs is one of the few internal kernel users that actually
|
|
* wants this _and_ can be built as a module. So we need to export
|
|
* this symbol for autofs, even though it really isn't appropriate
|
|
* for any other kernel modules.
|
|
*/
|
|
EXPORT_SYMBOL_GPL(__kernel_write);
|
|
|
|
ssize_t kernel_write(struct file *file, const void *buf, size_t count,
|
|
loff_t *pos)
|
|
{
|
|
ssize_t ret;
|
|
|
|
ret = rw_verify_area(WRITE, file, pos, count);
|
|
if (ret)
|
|
return ret;
|
|
|
|
file_start_write(file);
|
|
ret = __kernel_write(file, buf, count, pos);
|
|
file_end_write(file);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kernel_write);
|
|
|
|
ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
|
|
{
|
|
ssize_t ret;
|
|
|
|
if (!(file->f_mode & FMODE_WRITE))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_WRITE))
|
|
return -EINVAL;
|
|
if (unlikely(!access_ok(buf, count)))
|
|
return -EFAULT;
|
|
|
|
ret = rw_verify_area(WRITE, file, pos, count);
|
|
if (ret)
|
|
return ret;
|
|
if (count > MAX_RW_COUNT)
|
|
count = MAX_RW_COUNT;
|
|
file_start_write(file);
|
|
if (file->f_op->write)
|
|
ret = file->f_op->write(file, buf, count, pos);
|
|
else if (file->f_op->write_iter)
|
|
ret = new_sync_write(file, buf, count, pos);
|
|
else
|
|
ret = -EINVAL;
|
|
if (ret > 0) {
|
|
fsnotify_modify(file);
|
|
add_wchar(current, ret);
|
|
}
|
|
inc_syscw(current);
|
|
file_end_write(file);
|
|
return ret;
|
|
}
|
|
|
|
/* file_ppos returns &file->f_pos or NULL if file is stream */
|
|
static inline loff_t *file_ppos(struct file *file)
|
|
{
|
|
return file->f_mode & FMODE_STREAM ? NULL : &file->f_pos;
|
|
}
|
|
|
|
ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (f.file) {
|
|
loff_t pos, *ppos = file_ppos(f.file);
|
|
if (ppos) {
|
|
pos = *ppos;
|
|
ppos = &pos;
|
|
}
|
|
ret = vfs_read(f.file, buf, count, ppos);
|
|
if (ret >= 0 && ppos)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
|
|
{
|
|
return ksys_read(fd, buf, count);
|
|
}
|
|
|
|
ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (f.file) {
|
|
loff_t pos, *ppos = file_ppos(f.file);
|
|
if (ppos) {
|
|
pos = *ppos;
|
|
ppos = &pos;
|
|
}
|
|
ret = vfs_write(f.file, buf, count, ppos);
|
|
if (ret >= 0 && ppos)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
|
|
size_t, count)
|
|
{
|
|
return ksys_write(fd, buf, count);
|
|
}
|
|
|
|
ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count,
|
|
loff_t pos)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
|
|
f = fdget(fd);
|
|
if (f.file) {
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PREAD)
|
|
ret = vfs_read(f.file, buf, count, &pos);
|
|
fdput(f);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
|
|
size_t, count, loff_t, pos)
|
|
{
|
|
return ksys_pread64(fd, buf, count, pos);
|
|
}
|
|
|
|
ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf,
|
|
size_t count, loff_t pos)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
|
|
f = fdget(fd);
|
|
if (f.file) {
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PWRITE)
|
|
ret = vfs_write(f.file, buf, count, &pos);
|
|
fdput(f);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
|
|
size_t, count, loff_t, pos)
|
|
{
|
|
return ksys_pwrite64(fd, buf, count, pos);
|
|
}
|
|
|
|
static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
|
|
loff_t *ppos, int type, rwf_t flags)
|
|
{
|
|
struct kiocb kiocb;
|
|
ssize_t ret;
|
|
|
|
init_sync_kiocb(&kiocb, filp);
|
|
ret = kiocb_set_rw_flags(&kiocb, flags);
|
|
if (ret)
|
|
return ret;
|
|
kiocb.ki_pos = (ppos ? *ppos : 0);
|
|
|
|
if (type == READ)
|
|
ret = call_read_iter(filp, &kiocb, iter);
|
|
else
|
|
ret = call_write_iter(filp, &kiocb, iter);
|
|
BUG_ON(ret == -EIOCBQUEUED);
|
|
if (ppos)
|
|
*ppos = kiocb.ki_pos;
|
|
return ret;
|
|
}
|
|
|
|
/* Do it by hand, with file-ops */
|
|
static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
|
|
loff_t *ppos, int type, rwf_t flags)
|
|
{
|
|
ssize_t ret = 0;
|
|
|
|
if (flags & ~RWF_HIPRI)
|
|
return -EOPNOTSUPP;
|
|
|
|
while (iov_iter_count(iter)) {
|
|
struct iovec iovec = iov_iter_iovec(iter);
|
|
ssize_t nr;
|
|
|
|
if (type == READ) {
|
|
nr = filp->f_op->read(filp, iovec.iov_base,
|
|
iovec.iov_len, ppos);
|
|
} else {
|
|
nr = filp->f_op->write(filp, iovec.iov_base,
|
|
iovec.iov_len, ppos);
|
|
}
|
|
|
|
if (nr < 0) {
|
|
if (!ret)
|
|
ret = nr;
|
|
break;
|
|
}
|
|
ret += nr;
|
|
if (nr != iovec.iov_len)
|
|
break;
|
|
iov_iter_advance(iter, nr);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t do_iter_read(struct file *file, struct iov_iter *iter,
|
|
loff_t *pos, rwf_t flags)
|
|
{
|
|
size_t tot_len;
|
|
ssize_t ret = 0;
|
|
|
|
if (!(file->f_mode & FMODE_READ))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_READ))
|
|
return -EINVAL;
|
|
|
|
tot_len = iov_iter_count(iter);
|
|
if (!tot_len)
|
|
goto out;
|
|
ret = rw_verify_area(READ, file, pos, tot_len);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (file->f_op->read_iter)
|
|
ret = do_iter_readv_writev(file, iter, pos, READ, flags);
|
|
else
|
|
ret = do_loop_readv_writev(file, iter, pos, READ, flags);
|
|
out:
|
|
if (ret >= 0)
|
|
fsnotify_access(file);
|
|
return ret;
|
|
}
|
|
|
|
ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb,
|
|
struct iov_iter *iter)
|
|
{
|
|
size_t tot_len;
|
|
ssize_t ret = 0;
|
|
|
|
if (!file->f_op->read_iter)
|
|
return -EINVAL;
|
|
if (!(file->f_mode & FMODE_READ))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_READ))
|
|
return -EINVAL;
|
|
|
|
tot_len = iov_iter_count(iter);
|
|
if (!tot_len)
|
|
goto out;
|
|
ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = call_read_iter(file, iocb, iter);
|
|
out:
|
|
if (ret >= 0)
|
|
fsnotify_access(file);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(vfs_iocb_iter_read);
|
|
|
|
ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
|
|
rwf_t flags)
|
|
{
|
|
if (!file->f_op->read_iter)
|
|
return -EINVAL;
|
|
return do_iter_read(file, iter, ppos, flags);
|
|
}
|
|
EXPORT_SYMBOL(vfs_iter_read);
|
|
|
|
static ssize_t do_iter_write(struct file *file, struct iov_iter *iter,
|
|
loff_t *pos, rwf_t flags)
|
|
{
|
|
size_t tot_len;
|
|
ssize_t ret = 0;
|
|
|
|
if (!(file->f_mode & FMODE_WRITE))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_WRITE))
|
|
return -EINVAL;
|
|
|
|
tot_len = iov_iter_count(iter);
|
|
if (!tot_len)
|
|
return 0;
|
|
ret = rw_verify_area(WRITE, file, pos, tot_len);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (file->f_op->write_iter)
|
|
ret = do_iter_readv_writev(file, iter, pos, WRITE, flags);
|
|
else
|
|
ret = do_loop_readv_writev(file, iter, pos, WRITE, flags);
|
|
if (ret > 0)
|
|
fsnotify_modify(file);
|
|
return ret;
|
|
}
|
|
|
|
ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
|
|
struct iov_iter *iter)
|
|
{
|
|
size_t tot_len;
|
|
ssize_t ret = 0;
|
|
|
|
if (!file->f_op->write_iter)
|
|
return -EINVAL;
|
|
if (!(file->f_mode & FMODE_WRITE))
|
|
return -EBADF;
|
|
if (!(file->f_mode & FMODE_CAN_WRITE))
|
|
return -EINVAL;
|
|
|
|
tot_len = iov_iter_count(iter);
|
|
if (!tot_len)
|
|
return 0;
|
|
ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = call_write_iter(file, iocb, iter);
|
|
if (ret > 0)
|
|
fsnotify_modify(file);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(vfs_iocb_iter_write);
|
|
|
|
ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
|
|
rwf_t flags)
|
|
{
|
|
if (!file->f_op->write_iter)
|
|
return -EINVAL;
|
|
return do_iter_write(file, iter, ppos, flags);
|
|
}
|
|
EXPORT_SYMBOL(vfs_iter_write);
|
|
|
|
static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
|
|
unsigned long vlen, loff_t *pos, rwf_t flags)
|
|
{
|
|
struct iovec iovstack[UIO_FASTIOV];
|
|
struct iovec *iov = iovstack;
|
|
struct iov_iter iter;
|
|
ssize_t ret;
|
|
|
|
ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
|
|
if (ret >= 0) {
|
|
ret = do_iter_read(file, &iter, pos, flags);
|
|
kfree(iov);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
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];
|
|
struct iovec *iov = iovstack;
|
|
struct iov_iter iter;
|
|
ssize_t ret;
|
|
|
|
ret = import_iovec(WRITE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
|
|
if (ret >= 0) {
|
|
file_start_write(file);
|
|
ret = do_iter_write(file, &iter, pos, flags);
|
|
file_end_write(file);
|
|
kfree(iov);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
|
|
unsigned long vlen, rwf_t flags)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (f.file) {
|
|
loff_t pos, *ppos = file_ppos(f.file);
|
|
if (ppos) {
|
|
pos = *ppos;
|
|
ppos = &pos;
|
|
}
|
|
ret = vfs_readv(f.file, vec, vlen, ppos, flags);
|
|
if (ret >= 0 && ppos)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_rchar(current, ret);
|
|
inc_syscr(current);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec,
|
|
unsigned long vlen, rwf_t flags)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (f.file) {
|
|
loff_t pos, *ppos = file_ppos(f.file);
|
|
if (ppos) {
|
|
pos = *ppos;
|
|
ppos = &pos;
|
|
}
|
|
ret = vfs_writev(f.file, vec, vlen, ppos, flags);
|
|
if (ret >= 0 && ppos)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_wchar(current, ret);
|
|
inc_syscw(current);
|
|
return ret;
|
|
}
|
|
|
|
static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
|
|
{
|
|
#define HALF_LONG_BITS (BITS_PER_LONG / 2)
|
|
return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
|
|
}
|
|
|
|
static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec,
|
|
unsigned long vlen, loff_t pos, rwf_t flags)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
|
|
f = fdget(fd);
|
|
if (f.file) {
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PREAD)
|
|
ret = vfs_readv(f.file, vec, vlen, &pos, flags);
|
|
fdput(f);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_rchar(current, ret);
|
|
inc_syscr(current);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec,
|
|
unsigned long vlen, loff_t pos, rwf_t flags)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret = -EBADF;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
|
|
f = fdget(fd);
|
|
if (f.file) {
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PWRITE)
|
|
ret = vfs_writev(f.file, vec, vlen, &pos, flags);
|
|
fdput(f);
|
|
}
|
|
|
|
if (ret > 0)
|
|
add_wchar(current, ret);
|
|
inc_syscw(current);
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen)
|
|
{
|
|
return do_readv(fd, vec, vlen, 0);
|
|
}
|
|
|
|
SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen)
|
|
{
|
|
return do_writev(fd, vec, vlen, 0);
|
|
}
|
|
|
|
SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
|
|
{
|
|
loff_t pos = pos_from_hilo(pos_h, pos_l);
|
|
|
|
return do_preadv(fd, vec, vlen, pos, 0);
|
|
}
|
|
|
|
SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
|
|
rwf_t, flags)
|
|
{
|
|
loff_t pos = pos_from_hilo(pos_h, pos_l);
|
|
|
|
if (pos == -1)
|
|
return do_readv(fd, vec, vlen, flags);
|
|
|
|
return do_preadv(fd, vec, vlen, pos, flags);
|
|
}
|
|
|
|
SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
|
|
{
|
|
loff_t pos = pos_from_hilo(pos_h, pos_l);
|
|
|
|
return do_pwritev(fd, vec, vlen, pos, 0);
|
|
}
|
|
|
|
SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
|
|
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
|
|
rwf_t, flags)
|
|
{
|
|
loff_t pos = pos_from_hilo(pos_h, pos_l);
|
|
|
|
if (pos == -1)
|
|
return do_writev(fd, vec, vlen, flags);
|
|
|
|
return do_pwritev(fd, vec, vlen, pos, flags);
|
|
}
|
|
|
|
/*
|
|
* Various compat syscalls. Note that they all pretend to take a native
|
|
* iovec - import_iovec will properly treat those as compat_iovecs based on
|
|
* in_compat_syscall().
|
|
*/
|
|
#ifdef CONFIG_COMPAT
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
|
|
COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
|
|
const struct iovec __user *, vec,
|
|
unsigned long, vlen, loff_t, pos)
|
|
{
|
|
return do_preadv(fd, vec, vlen, pos, 0);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
|
|
const struct iovec __user *, vec,
|
|
compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
|
|
{
|
|
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
|
|
|
|
return do_preadv(fd, vec, vlen, pos, 0);
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
|
|
COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
|
|
const struct iovec __user *, vec,
|
|
unsigned long, vlen, loff_t, pos, rwf_t, flags)
|
|
{
|
|
if (pos == -1)
|
|
return do_readv(fd, vec, vlen, flags);
|
|
return do_preadv(fd, vec, vlen, pos, flags);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
|
|
const struct iovec __user *, vec,
|
|
compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
|
|
rwf_t, flags)
|
|
{
|
|
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
|
|
|
|
if (pos == -1)
|
|
return do_readv(fd, vec, vlen, flags);
|
|
return do_preadv(fd, vec, vlen, pos, flags);
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
|
|
COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
|
|
const struct iovec __user *, vec,
|
|
unsigned long, vlen, loff_t, pos)
|
|
{
|
|
return do_pwritev(fd, vec, vlen, pos, 0);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
|
|
const struct iovec __user *,vec,
|
|
compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
|
|
{
|
|
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
|
|
|
|
return do_pwritev(fd, vec, vlen, pos, 0);
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
|
|
COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
|
|
const struct iovec __user *, vec,
|
|
unsigned long, vlen, loff_t, pos, rwf_t, flags)
|
|
{
|
|
if (pos == -1)
|
|
return do_writev(fd, vec, vlen, flags);
|
|
return do_pwritev(fd, vec, vlen, pos, flags);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
|
|
const struct iovec __user *,vec,
|
|
compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags)
|
|
{
|
|
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
|
|
|
|
if (pos == -1)
|
|
return do_writev(fd, vec, vlen, flags);
|
|
return do_pwritev(fd, vec, vlen, pos, flags);
|
|
}
|
|
#endif /* CONFIG_COMPAT */
|
|
|
|
static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
|
|
size_t count, loff_t max)
|
|
{
|
|
struct fd in, out;
|
|
struct inode *in_inode, *out_inode;
|
|
struct pipe_inode_info *opipe;
|
|
loff_t pos;
|
|
loff_t out_pos;
|
|
ssize_t retval;
|
|
int fl;
|
|
|
|
/*
|
|
* Get input file, and verify that it is ok..
|
|
*/
|
|
retval = -EBADF;
|
|
in = fdget(in_fd);
|
|
if (!in.file)
|
|
goto out;
|
|
if (!(in.file->f_mode & FMODE_READ))
|
|
goto fput_in;
|
|
retval = -ESPIPE;
|
|
if (!ppos) {
|
|
pos = in.file->f_pos;
|
|
} else {
|
|
pos = *ppos;
|
|
if (!(in.file->f_mode & FMODE_PREAD))
|
|
goto fput_in;
|
|
}
|
|
retval = rw_verify_area(READ, in.file, &pos, count);
|
|
if (retval < 0)
|
|
goto fput_in;
|
|
if (count > MAX_RW_COUNT)
|
|
count = MAX_RW_COUNT;
|
|
|
|
/*
|
|
* Get output file, and verify that it is ok..
|
|
*/
|
|
retval = -EBADF;
|
|
out = fdget(out_fd);
|
|
if (!out.file)
|
|
goto fput_in;
|
|
if (!(out.file->f_mode & FMODE_WRITE))
|
|
goto fput_out;
|
|
in_inode = file_inode(in.file);
|
|
out_inode = file_inode(out.file);
|
|
out_pos = out.file->f_pos;
|
|
|
|
if (!max)
|
|
max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
|
|
|
|
if (unlikely(pos + count > max)) {
|
|
retval = -EOVERFLOW;
|
|
if (pos >= max)
|
|
goto fput_out;
|
|
count = max - pos;
|
|
}
|
|
|
|
fl = 0;
|
|
#if 0
|
|
/*
|
|
* We need to debate whether we can enable this or not. The
|
|
* man page documents EAGAIN return for the output at least,
|
|
* and the application is arguably buggy if it doesn't expect
|
|
* EAGAIN on a non-blocking file descriptor.
|
|
*/
|
|
if (in.file->f_flags & O_NONBLOCK)
|
|
fl = SPLICE_F_NONBLOCK;
|
|
#endif
|
|
opipe = get_pipe_info(out.file, true);
|
|
if (!opipe) {
|
|
retval = rw_verify_area(WRITE, out.file, &out_pos, count);
|
|
if (retval < 0)
|
|
goto fput_out;
|
|
file_start_write(out.file);
|
|
retval = do_splice_direct(in.file, &pos, out.file, &out_pos,
|
|
count, fl);
|
|
file_end_write(out.file);
|
|
} else {
|
|
retval = splice_file_to_pipe(in.file, opipe, &pos, count, fl);
|
|
}
|
|
|
|
if (retval > 0) {
|
|
add_rchar(current, retval);
|
|
add_wchar(current, retval);
|
|
fsnotify_access(in.file);
|
|
fsnotify_modify(out.file);
|
|
out.file->f_pos = out_pos;
|
|
if (ppos)
|
|
*ppos = pos;
|
|
else
|
|
in.file->f_pos = pos;
|
|
}
|
|
|
|
inc_syscr(current);
|
|
inc_syscw(current);
|
|
if (pos > max)
|
|
retval = -EOVERFLOW;
|
|
|
|
fput_out:
|
|
fdput(out);
|
|
fput_in:
|
|
fdput(in);
|
|
out:
|
|
return retval;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
|
|
{
|
|
loff_t pos;
|
|
off_t off;
|
|
ssize_t ret;
|
|
|
|
if (offset) {
|
|
if (unlikely(get_user(off, offset)))
|
|
return -EFAULT;
|
|
pos = off;
|
|
ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
|
|
if (unlikely(put_user(pos, offset)))
|
|
return -EFAULT;
|
|
return ret;
|
|
}
|
|
|
|
return do_sendfile(out_fd, in_fd, NULL, count, 0);
|
|
}
|
|
|
|
SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
|
|
{
|
|
loff_t pos;
|
|
ssize_t ret;
|
|
|
|
if (offset) {
|
|
if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
|
|
return -EFAULT;
|
|
ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
|
|
if (unlikely(put_user(pos, offset)))
|
|
return -EFAULT;
|
|
return ret;
|
|
}
|
|
|
|
return do_sendfile(out_fd, in_fd, NULL, count, 0);
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
|
|
compat_off_t __user *, offset, compat_size_t, count)
|
|
{
|
|
loff_t pos;
|
|
off_t off;
|
|
ssize_t ret;
|
|
|
|
if (offset) {
|
|
if (unlikely(get_user(off, offset)))
|
|
return -EFAULT;
|
|
pos = off;
|
|
ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
|
|
if (unlikely(put_user(pos, offset)))
|
|
return -EFAULT;
|
|
return ret;
|
|
}
|
|
|
|
return do_sendfile(out_fd, in_fd, NULL, count, 0);
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
|
|
compat_loff_t __user *, offset, compat_size_t, count)
|
|
{
|
|
loff_t pos;
|
|
ssize_t ret;
|
|
|
|
if (offset) {
|
|
if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
|
|
return -EFAULT;
|
|
ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
|
|
if (unlikely(put_user(pos, offset)))
|
|
return -EFAULT;
|
|
return ret;
|
|
}
|
|
|
|
return do_sendfile(out_fd, in_fd, NULL, count, 0);
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* generic_copy_file_range - copy data between two files
|
|
* @file_in: file structure to read from
|
|
* @pos_in: file offset to read from
|
|
* @file_out: file structure to write data to
|
|
* @pos_out: file offset to write data to
|
|
* @len: amount of data to copy
|
|
* @flags: copy flags
|
|
*
|
|
* This is a generic filesystem helper to copy data from one file to another.
|
|
* It has no constraints on the source or destination file owners - the files
|
|
* can belong to different superblocks and different filesystem types. Short
|
|
* copies are allowed.
|
|
*
|
|
* This should be called from the @file_out filesystem, as per the
|
|
* ->copy_file_range() method.
|
|
*
|
|
* Returns the number of bytes copied or a negative error indicating the
|
|
* failure.
|
|
*/
|
|
|
|
ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
size_t len, unsigned int flags)
|
|
{
|
|
return do_splice_direct(file_in, &pos_in, file_out, &pos_out,
|
|
len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
|
|
}
|
|
EXPORT_SYMBOL(generic_copy_file_range);
|
|
|
|
static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
size_t len, unsigned int flags)
|
|
{
|
|
/*
|
|
* Although we now allow filesystems to handle cross sb copy, passing
|
|
* a file of the wrong filesystem type to filesystem driver can result
|
|
* in an attempt to dereference the wrong type of ->private_data, so
|
|
* avoid doing that until we really have a good reason. NFS defines
|
|
* several different file_system_type structures, but they all end up
|
|
* using the same ->copy_file_range() function pointer.
|
|
*/
|
|
if (file_out->f_op->copy_file_range &&
|
|
file_out->f_op->copy_file_range == file_in->f_op->copy_file_range)
|
|
return file_out->f_op->copy_file_range(file_in, pos_in,
|
|
file_out, pos_out,
|
|
len, flags);
|
|
|
|
return generic_copy_file_range(file_in, pos_in, file_out, pos_out, len,
|
|
flags);
|
|
}
|
|
|
|
/*
|
|
* Performs necessary checks before doing a file copy
|
|
*
|
|
* Can adjust amount of bytes to copy via @req_count argument.
|
|
* Returns appropriate error code that caller should return or
|
|
* zero in case the copy should be allowed.
|
|
*/
|
|
static int generic_copy_file_checks(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
size_t *req_count, unsigned int flags)
|
|
{
|
|
struct inode *inode_in = file_inode(file_in);
|
|
struct inode *inode_out = file_inode(file_out);
|
|
uint64_t count = *req_count;
|
|
loff_t size_in;
|
|
int ret;
|
|
|
|
ret = generic_file_rw_checks(file_in, file_out);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Don't touch certain kinds of inodes */
|
|
if (IS_IMMUTABLE(inode_out))
|
|
return -EPERM;
|
|
|
|
if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
|
|
return -ETXTBSY;
|
|
|
|
/* Ensure offsets don't wrap. */
|
|
if (pos_in + count < pos_in || pos_out + count < pos_out)
|
|
return -EOVERFLOW;
|
|
|
|
/* Shorten the copy to EOF */
|
|
size_in = i_size_read(inode_in);
|
|
if (pos_in >= size_in)
|
|
count = 0;
|
|
else
|
|
count = min(count, size_in - (uint64_t)pos_in);
|
|
|
|
ret = generic_write_check_limits(file_out, pos_out, &count);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Don't allow overlapped copying within the same file. */
|
|
if (inode_in == inode_out &&
|
|
pos_out + count > pos_in &&
|
|
pos_out < pos_in + count)
|
|
return -EINVAL;
|
|
|
|
*req_count = count;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* copy_file_range() differs from regular file read and write in that it
|
|
* specifically allows return partial success. When it does so is up to
|
|
* the copy_file_range method.
|
|
*/
|
|
ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
size_t len, unsigned int flags)
|
|
{
|
|
ssize_t ret;
|
|
|
|
if (flags != 0)
|
|
return -EINVAL;
|
|
|
|
ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len,
|
|
flags);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
|
|
ret = rw_verify_area(READ, file_in, &pos_in, len);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
|
|
ret = rw_verify_area(WRITE, file_out, &pos_out, len);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
|
|
if (len == 0)
|
|
return 0;
|
|
|
|
file_start_write(file_out);
|
|
|
|
/*
|
|
* Try cloning first, this is supported by more file systems, and
|
|
* more efficient if both clone and copy are supported (e.g. NFS).
|
|
*/
|
|
if (file_in->f_op->remap_file_range &&
|
|
file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) {
|
|
loff_t cloned;
|
|
|
|
cloned = file_in->f_op->remap_file_range(file_in, pos_in,
|
|
file_out, pos_out,
|
|
min_t(loff_t, MAX_RW_COUNT, len),
|
|
REMAP_FILE_CAN_SHORTEN);
|
|
if (cloned > 0) {
|
|
ret = cloned;
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
ret = do_copy_file_range(file_in, pos_in, file_out, pos_out, len,
|
|
flags);
|
|
WARN_ON_ONCE(ret == -EOPNOTSUPP);
|
|
done:
|
|
if (ret > 0) {
|
|
fsnotify_access(file_in);
|
|
add_rchar(current, ret);
|
|
fsnotify_modify(file_out);
|
|
add_wchar(current, ret);
|
|
}
|
|
|
|
inc_syscr(current);
|
|
inc_syscw(current);
|
|
|
|
file_end_write(file_out);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(vfs_copy_file_range);
|
|
|
|
SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in,
|
|
int, fd_out, loff_t __user *, off_out,
|
|
size_t, len, unsigned int, flags)
|
|
{
|
|
loff_t pos_in;
|
|
loff_t pos_out;
|
|
struct fd f_in;
|
|
struct fd f_out;
|
|
ssize_t ret = -EBADF;
|
|
|
|
f_in = fdget(fd_in);
|
|
if (!f_in.file)
|
|
goto out2;
|
|
|
|
f_out = fdget(fd_out);
|
|
if (!f_out.file)
|
|
goto out1;
|
|
|
|
ret = -EFAULT;
|
|
if (off_in) {
|
|
if (copy_from_user(&pos_in, off_in, sizeof(loff_t)))
|
|
goto out;
|
|
} else {
|
|
pos_in = f_in.file->f_pos;
|
|
}
|
|
|
|
if (off_out) {
|
|
if (copy_from_user(&pos_out, off_out, sizeof(loff_t)))
|
|
goto out;
|
|
} else {
|
|
pos_out = f_out.file->f_pos;
|
|
}
|
|
|
|
ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len,
|
|
flags);
|
|
if (ret > 0) {
|
|
pos_in += ret;
|
|
pos_out += ret;
|
|
|
|
if (off_in) {
|
|
if (copy_to_user(off_in, &pos_in, sizeof(loff_t)))
|
|
ret = -EFAULT;
|
|
} else {
|
|
f_in.file->f_pos = pos_in;
|
|
}
|
|
|
|
if (off_out) {
|
|
if (copy_to_user(off_out, &pos_out, sizeof(loff_t)))
|
|
ret = -EFAULT;
|
|
} else {
|
|
f_out.file->f_pos = pos_out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
fdput(f_out);
|
|
out1:
|
|
fdput(f_in);
|
|
out2:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Don't operate on ranges the page cache doesn't support, and don't exceed the
|
|
* LFS limits. If pos is under the limit it becomes a short access. If it
|
|
* exceeds the limit we return -EFBIG.
|
|
*/
|
|
int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
loff_t max_size = inode->i_sb->s_maxbytes;
|
|
loff_t limit = rlimit(RLIMIT_FSIZE);
|
|
|
|
if (limit != RLIM_INFINITY) {
|
|
if (pos >= limit) {
|
|
send_sig(SIGXFSZ, current, 0);
|
|
return -EFBIG;
|
|
}
|
|
*count = min(*count, limit - pos);
|
|
}
|
|
|
|
if (!(file->f_flags & O_LARGEFILE))
|
|
max_size = MAX_NON_LFS;
|
|
|
|
if (unlikely(pos >= max_size))
|
|
return -EFBIG;
|
|
|
|
*count = min(*count, max_size - pos);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Performs necessary checks before doing a write
|
|
*
|
|
* Can adjust writing position or amount of bytes to write.
|
|
* Returns appropriate error code that caller should return or
|
|
* zero in case that write should be allowed.
|
|
*/
|
|
ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct inode *inode = file->f_mapping->host;
|
|
loff_t count;
|
|
int ret;
|
|
|
|
if (IS_SWAPFILE(inode))
|
|
return -ETXTBSY;
|
|
|
|
if (!iov_iter_count(from))
|
|
return 0;
|
|
|
|
/* FIXME: this is for backwards compatibility with 2.4 */
|
|
if (iocb->ki_flags & IOCB_APPEND)
|
|
iocb->ki_pos = i_size_read(inode);
|
|
|
|
if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
|
|
return -EINVAL;
|
|
|
|
count = iov_iter_count(from);
|
|
ret = generic_write_check_limits(file, iocb->ki_pos, &count);
|
|
if (ret)
|
|
return ret;
|
|
|
|
iov_iter_truncate(from, count);
|
|
return iov_iter_count(from);
|
|
}
|
|
EXPORT_SYMBOL(generic_write_checks);
|
|
|
|
/*
|
|
* Performs common checks before doing a file copy/clone
|
|
* from @file_in to @file_out.
|
|
*/
|
|
int generic_file_rw_checks(struct file *file_in, struct file *file_out)
|
|
{
|
|
struct inode *inode_in = file_inode(file_in);
|
|
struct inode *inode_out = file_inode(file_out);
|
|
|
|
/* Don't copy dirs, pipes, sockets... */
|
|
if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
|
|
return -EISDIR;
|
|
if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
|
|
return -EINVAL;
|
|
|
|
if (!(file_in->f_mode & FMODE_READ) ||
|
|
!(file_out->f_mode & FMODE_WRITE) ||
|
|
(file_out->f_flags & O_APPEND))
|
|
return -EBADF;
|
|
|
|
return 0;
|
|
}
|