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![Darrick J. Wong](/assets/img/avatar_default.png)
When dedupe wants to use the page cache to compare parts of two files
for dedupe, we must be very careful to handle locking correctly. The
current code doesn't do this. It must lock and unlock the page only
once if the two pages are the same, since the overlapping range check
doesn't catch this when blocksize < pagesize. If the pages are distinct
but from the same file, we must observe page locking order and lock them
in order of increasing offset to avoid clashing with writeback locking.
Fixes: 876bec6f9b
("vfs: refactor clone/dedupe_file_range common functions")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2225 lines
52 KiB
C
2225 lines
52 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/read_write.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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#include <linux/slab.h>
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#include <linux/stat.h>
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#include <linux/sched/xacct.h>
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#include <linux/fcntl.h>
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#include <linux/file.h>
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#include <linux/uio.h>
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#include <linux/fsnotify.h>
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#include <linux/security.h>
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#include <linux/export.h>
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#include <linux/syscalls.h>
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#include <linux/pagemap.h>
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#include <linux/splice.h>
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#include <linux/compat.h>
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#include <linux/mount.h>
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#include <linux/fs.h>
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#include "internal.h"
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#include <linux/uaccess.h>
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#include <asm/unistd.h>
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const struct file_operations generic_ro_fops = {
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.llseek = generic_file_llseek,
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.read_iter = generic_file_read_iter,
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.mmap = generic_file_readonly_mmap,
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.splice_read = generic_file_splice_read,
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};
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EXPORT_SYMBOL(generic_ro_fops);
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static inline bool unsigned_offsets(struct file *file)
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{
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return file->f_mode & FMODE_UNSIGNED_OFFSET;
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}
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/**
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* vfs_setpos - update the file offset for lseek
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* @file: file structure in question
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* @offset: file offset to seek to
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* @maxsize: maximum file size
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*
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* This is a low-level filesystem helper for updating the file offset to
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* the value specified by @offset if the given offset is valid and it is
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* not equal to the current file offset.
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*
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* Return the specified offset on success and -EINVAL on invalid offset.
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*/
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loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)
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{
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if (offset < 0 && !unsigned_offsets(file))
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return -EINVAL;
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if (offset > maxsize)
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return -EINVAL;
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if (offset != file->f_pos) {
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file->f_pos = offset;
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file->f_version = 0;
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}
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return offset;
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}
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EXPORT_SYMBOL(vfs_setpos);
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/**
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* generic_file_llseek_size - generic llseek implementation for regular files
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @whence: type of seek
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* @size: max size of this file in file system
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* @eof: offset used for SEEK_END position
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*
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* This is a variant of generic_file_llseek that allows passing in a custom
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* maximum file size and a custom EOF position, for e.g. hashed directories
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*
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* Synchronization:
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* SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms)
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* SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes.
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* read/writes behave like SEEK_SET against seeks.
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*/
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loff_t
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generic_file_llseek_size(struct file *file, loff_t offset, int whence,
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loff_t maxsize, loff_t eof)
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{
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switch (whence) {
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case SEEK_END:
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offset += eof;
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break;
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case SEEK_CUR:
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/*
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* Here we special-case the lseek(fd, 0, SEEK_CUR)
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* position-querying operation. Avoid rewriting the "same"
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* f_pos value back to the file because a concurrent read(),
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* write() or lseek() might have altered it
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*/
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if (offset == 0)
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return file->f_pos;
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/*
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* f_lock protects against read/modify/write race with other
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* SEEK_CURs. Note that parallel writes and reads behave
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* like SEEK_SET.
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*/
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spin_lock(&file->f_lock);
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offset = vfs_setpos(file, file->f_pos + offset, maxsize);
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spin_unlock(&file->f_lock);
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return offset;
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case SEEK_DATA:
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/*
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* In the generic case the entire file is data, so as long as
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* offset isn't at the end of the file then the offset is data.
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*/
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if ((unsigned long long)offset >= eof)
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return -ENXIO;
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break;
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case SEEK_HOLE:
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/*
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* There is a virtual hole at the end of the file, so as long as
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* offset isn't i_size or larger, return i_size.
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*/
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if ((unsigned long long)offset >= eof)
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return -ENXIO;
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offset = eof;
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break;
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}
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return vfs_setpos(file, offset, maxsize);
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}
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EXPORT_SYMBOL(generic_file_llseek_size);
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/**
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* generic_file_llseek - generic llseek implementation for regular files
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @whence: type of seek
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*
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* This is a generic implemenation of ->llseek useable for all normal local
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* filesystems. It just updates the file offset to the value specified by
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* @offset and @whence.
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*/
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loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)
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{
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struct inode *inode = file->f_mapping->host;
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return generic_file_llseek_size(file, offset, whence,
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inode->i_sb->s_maxbytes,
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i_size_read(inode));
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}
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EXPORT_SYMBOL(generic_file_llseek);
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/**
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* fixed_size_llseek - llseek implementation for fixed-sized devices
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @whence: type of seek
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* @size: size of the file
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*
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*/
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loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)
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{
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switch (whence) {
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case SEEK_SET: case SEEK_CUR: case SEEK_END:
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return generic_file_llseek_size(file, offset, whence,
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size, size);
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default:
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return -EINVAL;
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}
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}
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EXPORT_SYMBOL(fixed_size_llseek);
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/**
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* no_seek_end_llseek - llseek implementation for fixed-sized devices
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @whence: type of seek
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*
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*/
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loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence)
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{
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switch (whence) {
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case SEEK_SET: case SEEK_CUR:
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return generic_file_llseek_size(file, offset, whence,
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OFFSET_MAX, 0);
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default:
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return -EINVAL;
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}
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}
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EXPORT_SYMBOL(no_seek_end_llseek);
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/**
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* no_seek_end_llseek_size - llseek implementation for fixed-sized devices
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @whence: type of seek
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* @size: maximal offset allowed
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*
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*/
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loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size)
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{
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switch (whence) {
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case SEEK_SET: case SEEK_CUR:
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return generic_file_llseek_size(file, offset, whence,
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size, 0);
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default:
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return -EINVAL;
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}
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}
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EXPORT_SYMBOL(no_seek_end_llseek_size);
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/**
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* noop_llseek - No Operation Performed llseek implementation
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* @file: file structure to seek on
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* @offset: file offset to seek to
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* @whence: type of seek
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*
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* This is an implementation of ->llseek useable for the rare special case when
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* userspace expects the seek to succeed but the (device) file is actually not
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* able to perform the seek. In this case you use noop_llseek() instead of
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* falling back to the default implementation of ->llseek.
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*/
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loff_t noop_llseek(struct file *file, loff_t offset, int whence)
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{
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return file->f_pos;
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}
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EXPORT_SYMBOL(noop_llseek);
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loff_t no_llseek(struct file *file, loff_t offset, int whence)
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{
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return -ESPIPE;
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}
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EXPORT_SYMBOL(no_llseek);
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loff_t default_llseek(struct file *file, loff_t offset, int whence)
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{
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struct inode *inode = file_inode(file);
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loff_t retval;
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inode_lock(inode);
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switch (whence) {
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case SEEK_END:
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offset += i_size_read(inode);
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break;
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case SEEK_CUR:
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if (offset == 0) {
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retval = file->f_pos;
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goto out;
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}
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offset += file->f_pos;
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break;
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case SEEK_DATA:
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/*
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* In the generic case the entire file is data, so as
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* long as offset isn't at the end of the file then the
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* offset is data.
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*/
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if (offset >= inode->i_size) {
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retval = -ENXIO;
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goto out;
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}
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break;
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case SEEK_HOLE:
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/*
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* There is a virtual hole at the end of the file, so
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* as long as offset isn't i_size or larger, return
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* i_size.
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*/
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if (offset >= inode->i_size) {
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retval = -ENXIO;
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goto out;
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}
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offset = inode->i_size;
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break;
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}
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retval = -EINVAL;
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if (offset >= 0 || unsigned_offsets(file)) {
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if (offset != file->f_pos) {
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file->f_pos = offset;
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file->f_version = 0;
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}
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retval = offset;
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}
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out:
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inode_unlock(inode);
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return retval;
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}
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EXPORT_SYMBOL(default_llseek);
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loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
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{
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loff_t (*fn)(struct file *, loff_t, int);
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fn = no_llseek;
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if (file->f_mode & FMODE_LSEEK) {
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if (file->f_op->llseek)
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fn = file->f_op->llseek;
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}
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return fn(file, offset, whence);
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}
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EXPORT_SYMBOL(vfs_llseek);
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off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence)
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{
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off_t retval;
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struct fd f = fdget_pos(fd);
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if (!f.file)
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return -EBADF;
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retval = -EINVAL;
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if (whence <= SEEK_MAX) {
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loff_t res = vfs_llseek(f.file, offset, whence);
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retval = res;
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if (res != (loff_t)retval)
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retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */
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}
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fdput_pos(f);
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return retval;
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}
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SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
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{
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return ksys_lseek(fd, offset, whence);
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}
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#ifdef CONFIG_COMPAT
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COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
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{
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return ksys_lseek(fd, offset, whence);
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}
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#endif
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#if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT)
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SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
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unsigned long, offset_low, loff_t __user *, result,
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unsigned int, whence)
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{
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int retval;
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struct fd f = fdget_pos(fd);
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loff_t offset;
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if (!f.file)
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return -EBADF;
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retval = -EINVAL;
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if (whence > SEEK_MAX)
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goto out_putf;
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offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
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whence);
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retval = (int)offset;
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if (offset >= 0) {
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retval = -EFAULT;
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if (!copy_to_user(result, &offset, sizeof(offset)))
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retval = 0;
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}
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out_putf:
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fdput_pos(f);
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return retval;
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}
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#endif
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int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
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{
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struct inode *inode;
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int retval = -EINVAL;
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inode = file_inode(file);
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if (unlikely((ssize_t) count < 0))
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return retval;
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/*
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* ranged mandatory locking does not apply to streams - it makes sense
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* only for files where position has a meaning.
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*/
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if (ppos) {
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loff_t pos = *ppos;
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if (unlikely(pos < 0)) {
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if (!unsigned_offsets(file))
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return retval;
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if (count >= -pos) /* both values are in 0..LLONG_MAX */
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return -EOVERFLOW;
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} else if (unlikely((loff_t) (pos + count) < 0)) {
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if (!unsigned_offsets(file))
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return retval;
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}
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|
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if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
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retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
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read_write == READ ? F_RDLCK : F_WRLCK);
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if (retval < 0)
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return retval;
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}
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}
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|
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return security_file_permission(file,
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read_write == READ ? MAY_READ : MAY_WRITE);
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}
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|
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static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
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{
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struct iovec iov = { .iov_base = buf, .iov_len = len };
|
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struct kiocb kiocb;
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struct iov_iter iter;
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ssize_t ret;
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init_sync_kiocb(&kiocb, filp);
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kiocb.ki_pos = (ppos ? *ppos : 0);
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iov_iter_init(&iter, READ, &iov, 1, len);
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ret = call_read_iter(filp, &kiocb, &iter);
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BUG_ON(ret == -EIOCBQUEUED);
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if (ppos)
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*ppos = kiocb.ki_pos;
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return ret;
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}
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|
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ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
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loff_t *pos)
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{
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if (file->f_op->read)
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return file->f_op->read(file, buf, count, pos);
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else if (file->f_op->read_iter)
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return new_sync_read(file, buf, count, pos);
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else
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return -EINVAL;
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}
|
|
|
|
ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
|
|
{
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|
mm_segment_t old_fs;
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|
ssize_t result;
|
|
|
|
old_fs = get_fs();
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set_fs(KERNEL_DS);
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/* The cast to a user pointer is valid due to the set_fs() */
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result = vfs_read(file, (void __user *)buf, count, pos);
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set_fs(old_fs);
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return result;
|
|
}
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EXPORT_SYMBOL(kernel_read);
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|
|
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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) {
|
|
if (count > MAX_RW_COUNT)
|
|
count = MAX_RW_COUNT;
|
|
ret = __vfs_read(file, buf, count, pos);
|
|
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;
|
|
}
|
|
|
|
static ssize_t __vfs_write(struct file *file, const char __user *p,
|
|
size_t count, loff_t *pos)
|
|
{
|
|
if (file->f_op->write)
|
|
return file->f_op->write(file, p, count, pos);
|
|
else if (file->f_op->write_iter)
|
|
return new_sync_write(file, p, count, pos);
|
|
else
|
|
return -EINVAL;
|
|
}
|
|
|
|
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;
|
|
ssize_t ret;
|
|
|
|
if (!(file->f_mode & FMODE_CAN_WRITE))
|
|
return -EINVAL;
|
|
|
|
old_fs = get_fs();
|
|
set_fs(KERNEL_DS);
|
|
p = (__force const char __user *)buf;
|
|
if (count > MAX_RW_COUNT)
|
|
count = MAX_RW_COUNT;
|
|
ret = __vfs_write(file, p, count, pos);
|
|
set_fs(old_fs);
|
|
if (ret > 0) {
|
|
fsnotify_modify(file);
|
|
add_wchar(current, ret);
|
|
}
|
|
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(KERNEL_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)
|
|
{
|
|
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) {
|
|
if (count > MAX_RW_COUNT)
|
|
count = MAX_RW_COUNT;
|
|
file_start_write(file);
|
|
ret = __vfs_write(file, buf, count, pos);
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* rw_copy_check_uvector() - Copy an array of &struct iovec from userspace
|
|
* into the kernel and check that it is valid.
|
|
*
|
|
* @type: One of %CHECK_IOVEC_ONLY, %READ, or %WRITE.
|
|
* @uvector: Pointer to the userspace array.
|
|
* @nr_segs: Number of elements in userspace array.
|
|
* @fast_segs: Number of elements in @fast_pointer.
|
|
* @fast_pointer: Pointer to (usually small on-stack) kernel array.
|
|
* @ret_pointer: (output parameter) Pointer to a variable that will point to
|
|
* either @fast_pointer, a newly allocated kernel array, or NULL,
|
|
* depending on which array was used.
|
|
*
|
|
* This function copies an array of &struct iovec of @nr_segs from
|
|
* userspace into the kernel and checks that each element is valid (e.g.
|
|
* it does not point to a kernel address or cause overflow by being too
|
|
* large, etc.).
|
|
*
|
|
* As an optimization, the caller may provide a pointer to a small
|
|
* on-stack array in @fast_pointer, typically %UIO_FASTIOV elements long
|
|
* (the size of this array, or 0 if unused, should be given in @fast_segs).
|
|
*
|
|
* @ret_pointer will always point to the array that was used, so the
|
|
* caller must take care not to call kfree() on it e.g. in case the
|
|
* @fast_pointer array was used and it was allocated on the stack.
|
|
*
|
|
* Return: The total number of bytes covered by the iovec array on success
|
|
* or a negative error code on error.
|
|
*/
|
|
ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
|
|
unsigned long nr_segs, unsigned long fast_segs,
|
|
struct iovec *fast_pointer,
|
|
struct iovec **ret_pointer)
|
|
{
|
|
unsigned long seg;
|
|
ssize_t ret;
|
|
struct iovec *iov = fast_pointer;
|
|
|
|
/*
|
|
* SuS says "The readv() function *may* fail if the iovcnt argument
|
|
* was less than or equal to 0, or greater than {IOV_MAX}. Linux has
|
|
* traditionally returned zero for zero segments, so...
|
|
*/
|
|
if (nr_segs == 0) {
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* First get the "struct iovec" from user memory and
|
|
* verify all the pointers
|
|
*/
|
|
if (nr_segs > UIO_MAXIOV) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (nr_segs > fast_segs) {
|
|
iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL);
|
|
if (iov == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
}
|
|
if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* According to the Single Unix Specification we should return EINVAL
|
|
* if an element length is < 0 when cast to ssize_t or if the
|
|
* total length would overflow the ssize_t return value of the
|
|
* system call.
|
|
*
|
|
* Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
|
|
* overflow case.
|
|
*/
|
|
ret = 0;
|
|
for (seg = 0; seg < nr_segs; seg++) {
|
|
void __user *buf = iov[seg].iov_base;
|
|
ssize_t len = (ssize_t)iov[seg].iov_len;
|
|
|
|
/* see if we we're about to use an invalid len or if
|
|
* it's about to overflow ssize_t */
|
|
if (len < 0) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (type >= 0
|
|
&& unlikely(!access_ok(buf, len))) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
if (len > MAX_RW_COUNT - ret) {
|
|
len = MAX_RW_COUNT - ret;
|
|
iov[seg].iov_len = len;
|
|
}
|
|
ret += len;
|
|
}
|
|
out:
|
|
*ret_pointer = iov;
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
ssize_t compat_rw_copy_check_uvector(int type,
|
|
const struct compat_iovec __user *uvector, unsigned long nr_segs,
|
|
unsigned long fast_segs, struct iovec *fast_pointer,
|
|
struct iovec **ret_pointer)
|
|
{
|
|
compat_ssize_t tot_len;
|
|
struct iovec *iov = *ret_pointer = fast_pointer;
|
|
ssize_t ret = 0;
|
|
int seg;
|
|
|
|
/*
|
|
* SuS says "The readv() function *may* fail if the iovcnt argument
|
|
* was less than or equal to 0, or greater than {IOV_MAX}. Linux has
|
|
* traditionally returned zero for zero segments, so...
|
|
*/
|
|
if (nr_segs == 0)
|
|
goto out;
|
|
|
|
ret = -EINVAL;
|
|
if (nr_segs > UIO_MAXIOV)
|
|
goto out;
|
|
if (nr_segs > fast_segs) {
|
|
ret = -ENOMEM;
|
|
iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL);
|
|
if (iov == NULL)
|
|
goto out;
|
|
}
|
|
*ret_pointer = iov;
|
|
|
|
ret = -EFAULT;
|
|
if (!access_ok(uvector, nr_segs*sizeof(*uvector)))
|
|
goto out;
|
|
|
|
/*
|
|
* Single unix specification:
|
|
* We should -EINVAL if an element length is not >= 0 and fitting an
|
|
* ssize_t.
|
|
*
|
|
* In Linux, the total length is limited to MAX_RW_COUNT, there is
|
|
* no overflow possibility.
|
|
*/
|
|
tot_len = 0;
|
|
ret = -EINVAL;
|
|
for (seg = 0; seg < nr_segs; seg++) {
|
|
compat_uptr_t buf;
|
|
compat_ssize_t len;
|
|
|
|
if (__get_user(len, &uvector->iov_len) ||
|
|
__get_user(buf, &uvector->iov_base)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
if (len < 0) /* size_t not fitting in compat_ssize_t .. */
|
|
goto out;
|
|
if (type >= 0 &&
|
|
!access_ok(compat_ptr(buf), len)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
if (len > MAX_RW_COUNT - tot_len)
|
|
len = MAX_RW_COUNT - tot_len;
|
|
tot_len += len;
|
|
iov->iov_base = compat_ptr(buf);
|
|
iov->iov_len = (compat_size_t) len;
|
|
uvector++;
|
|
iov++;
|
|
}
|
|
ret = tot_len;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
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_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_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);
|
|
|
|
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);
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static size_t compat_readv(struct file *file,
|
|
const struct compat_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 = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter);
|
|
if (ret >= 0) {
|
|
ret = do_iter_read(file, &iter, pos, flags);
|
|
kfree(iov);
|
|
}
|
|
if (ret > 0)
|
|
add_rchar(current, ret);
|
|
inc_syscr(current);
|
|
return ret;
|
|
}
|
|
|
|
static size_t do_compat_readv(compat_ulong_t fd,
|
|
const struct compat_iovec __user *vec,
|
|
compat_ulong_t vlen, rwf_t flags)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret;
|
|
loff_t pos;
|
|
|
|
if (!f.file)
|
|
return -EBADF;
|
|
pos = f.file->f_pos;
|
|
ret = compat_readv(f.file, vec, vlen, &pos, flags);
|
|
if (ret >= 0)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
return ret;
|
|
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
compat_ulong_t, vlen)
|
|
{
|
|
return do_compat_readv(fd, vec, vlen, 0);
|
|
}
|
|
|
|
static long do_compat_preadv64(unsigned long fd,
|
|
const struct compat_iovec __user *vec,
|
|
unsigned long vlen, loff_t pos, rwf_t flags)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
f = fdget(fd);
|
|
if (!f.file)
|
|
return -EBADF;
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PREAD)
|
|
ret = compat_readv(f.file, vec, vlen, &pos, flags);
|
|
fdput(f);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
|
|
COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
unsigned long, vlen, loff_t, pos)
|
|
{
|
|
return do_compat_preadv64(fd, vec, vlen, pos, 0);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
|
|
const struct compat_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_compat_preadv64(fd, vec, vlen, pos, 0);
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
|
|
COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
unsigned long, vlen, loff_t, pos, rwf_t, flags)
|
|
{
|
|
if (pos == -1)
|
|
return do_compat_readv(fd, vec, vlen, flags);
|
|
|
|
return do_compat_preadv64(fd, vec, vlen, pos, flags);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
|
|
const struct compat_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_compat_readv(fd, vec, vlen, flags);
|
|
|
|
return do_compat_preadv64(fd, vec, vlen, pos, flags);
|
|
}
|
|
|
|
static size_t compat_writev(struct file *file,
|
|
const struct compat_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 = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter);
|
|
if (ret >= 0) {
|
|
file_start_write(file);
|
|
ret = do_iter_write(file, &iter, pos, flags);
|
|
file_end_write(file);
|
|
kfree(iov);
|
|
}
|
|
if (ret > 0)
|
|
add_wchar(current, ret);
|
|
inc_syscw(current);
|
|
return ret;
|
|
}
|
|
|
|
static size_t do_compat_writev(compat_ulong_t fd,
|
|
const struct compat_iovec __user* vec,
|
|
compat_ulong_t vlen, rwf_t flags)
|
|
{
|
|
struct fd f = fdget_pos(fd);
|
|
ssize_t ret;
|
|
loff_t pos;
|
|
|
|
if (!f.file)
|
|
return -EBADF;
|
|
pos = f.file->f_pos;
|
|
ret = compat_writev(f.file, vec, vlen, &pos, flags);
|
|
if (ret >= 0)
|
|
f.file->f_pos = pos;
|
|
fdput_pos(f);
|
|
return ret;
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
|
|
const struct compat_iovec __user *, vec,
|
|
compat_ulong_t, vlen)
|
|
{
|
|
return do_compat_writev(fd, vec, vlen, 0);
|
|
}
|
|
|
|
static long do_compat_pwritev64(unsigned long fd,
|
|
const struct compat_iovec __user *vec,
|
|
unsigned long vlen, loff_t pos, rwf_t flags)
|
|
{
|
|
struct fd f;
|
|
ssize_t ret;
|
|
|
|
if (pos < 0)
|
|
return -EINVAL;
|
|
f = fdget(fd);
|
|
if (!f.file)
|
|
return -EBADF;
|
|
ret = -ESPIPE;
|
|
if (f.file->f_mode & FMODE_PWRITE)
|
|
ret = compat_writev(f.file, vec, vlen, &pos, flags);
|
|
fdput(f);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
|
|
COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
unsigned long, vlen, loff_t, pos)
|
|
{
|
|
return do_compat_pwritev64(fd, vec, vlen, pos, 0);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
|
|
const struct compat_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_compat_pwritev64(fd, vec, vlen, pos, 0);
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
|
|
COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
|
|
const struct compat_iovec __user *,vec,
|
|
unsigned long, vlen, loff_t, pos, rwf_t, flags)
|
|
{
|
|
if (pos == -1)
|
|
return do_compat_writev(fd, vec, vlen, flags);
|
|
|
|
return do_compat_pwritev64(fd, vec, vlen, pos, flags);
|
|
}
|
|
#endif
|
|
|
|
COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
|
|
const struct compat_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_compat_writev(fd, vec, vlen, flags);
|
|
|
|
return do_compat_pwritev64(fd, vec, vlen, pos, flags);
|
|
}
|
|
|
|
#endif
|
|
|
|
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;
|
|
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;
|
|
retval = rw_verify_area(WRITE, out.file, &out_pos, count);
|
|
if (retval < 0)
|
|
goto fput_out;
|
|
|
|
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
|
|
file_start_write(out.file);
|
|
retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
|
|
file_end_write(out.file);
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
static int remap_verify_area(struct file *file, loff_t pos, loff_t len,
|
|
bool write)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
|
|
if (unlikely(pos < 0 || len < 0))
|
|
return -EINVAL;
|
|
|
|
if (unlikely((loff_t) (pos + len) < 0))
|
|
return -EINVAL;
|
|
|
|
if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
|
|
loff_t end = len ? pos + len - 1 : OFFSET_MAX;
|
|
int retval;
|
|
|
|
retval = locks_mandatory_area(inode, file, pos, end,
|
|
write ? F_WRLCK : F_RDLCK);
|
|
if (retval < 0)
|
|
return retval;
|
|
}
|
|
|
|
return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
|
|
}
|
|
/*
|
|
* Ensure that we don't remap a partial EOF block in the middle of something
|
|
* else. Assume that the offsets have already been checked for block
|
|
* alignment.
|
|
*
|
|
* For deduplication we always scale down to the previous block because we
|
|
* can't meaningfully compare post-EOF contents.
|
|
*
|
|
* For clone we only link a partial EOF block above the destination file's EOF.
|
|
*
|
|
* Shorten the request if possible.
|
|
*/
|
|
static int generic_remap_check_len(struct inode *inode_in,
|
|
struct inode *inode_out,
|
|
loff_t pos_out,
|
|
loff_t *len,
|
|
unsigned int remap_flags)
|
|
{
|
|
u64 blkmask = i_blocksize(inode_in) - 1;
|
|
loff_t new_len = *len;
|
|
|
|
if ((*len & blkmask) == 0)
|
|
return 0;
|
|
|
|
if ((remap_flags & REMAP_FILE_DEDUP) ||
|
|
pos_out + *len < i_size_read(inode_out))
|
|
new_len &= ~blkmask;
|
|
|
|
if (new_len == *len)
|
|
return 0;
|
|
|
|
if (remap_flags & REMAP_FILE_CAN_SHORTEN) {
|
|
*len = new_len;
|
|
return 0;
|
|
}
|
|
|
|
return (remap_flags & REMAP_FILE_DEDUP) ? -EBADE : -EINVAL;
|
|
}
|
|
|
|
/* Read a page's worth of file data into the page cache. */
|
|
static struct page *vfs_dedupe_get_page(struct inode *inode, loff_t offset)
|
|
{
|
|
struct page *page;
|
|
|
|
page = read_mapping_page(inode->i_mapping, offset >> PAGE_SHIFT, NULL);
|
|
if (IS_ERR(page))
|
|
return page;
|
|
if (!PageUptodate(page)) {
|
|
put_page(page);
|
|
return ERR_PTR(-EIO);
|
|
}
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Lock two pages, ensuring that we lock in offset order if the pages are from
|
|
* the same file.
|
|
*/
|
|
static void vfs_lock_two_pages(struct page *page1, struct page *page2)
|
|
{
|
|
/* Always lock in order of increasing index. */
|
|
if (page1->index > page2->index)
|
|
swap(page1, page2);
|
|
|
|
lock_page(page1);
|
|
if (page1 != page2)
|
|
lock_page(page2);
|
|
}
|
|
|
|
/* Unlock two pages, being careful not to unlock the same page twice. */
|
|
static void vfs_unlock_two_pages(struct page *page1, struct page *page2)
|
|
{
|
|
unlock_page(page1);
|
|
if (page1 != page2)
|
|
unlock_page(page2);
|
|
}
|
|
|
|
/*
|
|
* Compare extents of two files to see if they are the same.
|
|
* Caller must have locked both inodes to prevent write races.
|
|
*/
|
|
static int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
|
|
struct inode *dest, loff_t destoff,
|
|
loff_t len, bool *is_same)
|
|
{
|
|
loff_t src_poff;
|
|
loff_t dest_poff;
|
|
void *src_addr;
|
|
void *dest_addr;
|
|
struct page *src_page;
|
|
struct page *dest_page;
|
|
loff_t cmp_len;
|
|
bool same;
|
|
int error;
|
|
|
|
error = -EINVAL;
|
|
same = true;
|
|
while (len) {
|
|
src_poff = srcoff & (PAGE_SIZE - 1);
|
|
dest_poff = destoff & (PAGE_SIZE - 1);
|
|
cmp_len = min(PAGE_SIZE - src_poff,
|
|
PAGE_SIZE - dest_poff);
|
|
cmp_len = min(cmp_len, len);
|
|
if (cmp_len <= 0)
|
|
goto out_error;
|
|
|
|
src_page = vfs_dedupe_get_page(src, srcoff);
|
|
if (IS_ERR(src_page)) {
|
|
error = PTR_ERR(src_page);
|
|
goto out_error;
|
|
}
|
|
dest_page = vfs_dedupe_get_page(dest, destoff);
|
|
if (IS_ERR(dest_page)) {
|
|
error = PTR_ERR(dest_page);
|
|
put_page(src_page);
|
|
goto out_error;
|
|
}
|
|
|
|
vfs_lock_two_pages(src_page, dest_page);
|
|
|
|
/*
|
|
* Now that we've locked both pages, make sure they're still
|
|
* mapped to the file data we're interested in. If not,
|
|
* someone is invalidating pages on us and we lose.
|
|
*/
|
|
if (!PageUptodate(src_page) || !PageUptodate(dest_page) ||
|
|
src_page->mapping != src->i_mapping ||
|
|
dest_page->mapping != dest->i_mapping) {
|
|
same = false;
|
|
goto unlock;
|
|
}
|
|
|
|
src_addr = kmap_atomic(src_page);
|
|
dest_addr = kmap_atomic(dest_page);
|
|
|
|
flush_dcache_page(src_page);
|
|
flush_dcache_page(dest_page);
|
|
|
|
if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len))
|
|
same = false;
|
|
|
|
kunmap_atomic(dest_addr);
|
|
kunmap_atomic(src_addr);
|
|
unlock:
|
|
vfs_unlock_two_pages(src_page, dest_page);
|
|
put_page(dest_page);
|
|
put_page(src_page);
|
|
|
|
if (!same)
|
|
break;
|
|
|
|
srcoff += cmp_len;
|
|
destoff += cmp_len;
|
|
len -= cmp_len;
|
|
}
|
|
|
|
*is_same = same;
|
|
return 0;
|
|
|
|
out_error:
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Check that the two inodes are eligible for cloning, the ranges make
|
|
* sense, and then flush all dirty data. Caller must ensure that the
|
|
* inodes have been locked against any other modifications.
|
|
*
|
|
* If there's an error, then the usual negative error code is returned.
|
|
* Otherwise returns 0 with *len set to the request length.
|
|
*/
|
|
int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
loff_t *len, unsigned int remap_flags)
|
|
{
|
|
struct inode *inode_in = file_inode(file_in);
|
|
struct inode *inode_out = file_inode(file_out);
|
|
bool same_inode = (inode_in == inode_out);
|
|
int 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;
|
|
|
|
/* Don't reflink 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;
|
|
|
|
/* Zero length dedupe exits immediately; reflink goes to EOF. */
|
|
if (*len == 0) {
|
|
loff_t isize = i_size_read(inode_in);
|
|
|
|
if ((remap_flags & REMAP_FILE_DEDUP) || pos_in == isize)
|
|
return 0;
|
|
if (pos_in > isize)
|
|
return -EINVAL;
|
|
*len = isize - pos_in;
|
|
if (*len == 0)
|
|
return 0;
|
|
}
|
|
|
|
/* Check that we don't violate system file offset limits. */
|
|
ret = generic_remap_checks(file_in, pos_in, file_out, pos_out, len,
|
|
remap_flags);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Wait for the completion of any pending IOs on both files */
|
|
inode_dio_wait(inode_in);
|
|
if (!same_inode)
|
|
inode_dio_wait(inode_out);
|
|
|
|
ret = filemap_write_and_wait_range(inode_in->i_mapping,
|
|
pos_in, pos_in + *len - 1);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = filemap_write_and_wait_range(inode_out->i_mapping,
|
|
pos_out, pos_out + *len - 1);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* Check that the extents are the same.
|
|
*/
|
|
if (remap_flags & REMAP_FILE_DEDUP) {
|
|
bool is_same = false;
|
|
|
|
ret = vfs_dedupe_file_range_compare(inode_in, pos_in,
|
|
inode_out, pos_out, *len, &is_same);
|
|
if (ret)
|
|
return ret;
|
|
if (!is_same)
|
|
return -EBADE;
|
|
}
|
|
|
|
ret = generic_remap_check_len(inode_in, inode_out, pos_out, len,
|
|
remap_flags);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* If can't alter the file contents, we're done. */
|
|
if (!(remap_flags & REMAP_FILE_DEDUP))
|
|
ret = file_modified(file_out);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(generic_remap_file_range_prep);
|
|
|
|
loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
loff_t len, unsigned int remap_flags)
|
|
{
|
|
loff_t ret;
|
|
|
|
WARN_ON_ONCE(remap_flags & REMAP_FILE_DEDUP);
|
|
|
|
/*
|
|
* FICLONE/FICLONERANGE ioctls enforce that src and dest files are on
|
|
* the same mount. Practically, they only need to be on the same file
|
|
* system.
|
|
*/
|
|
if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
|
|
return -EXDEV;
|
|
|
|
ret = generic_file_rw_checks(file_in, file_out);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (!file_in->f_op->remap_file_range)
|
|
return -EOPNOTSUPP;
|
|
|
|
ret = remap_verify_area(file_in, pos_in, len, false);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = remap_verify_area(file_out, pos_out, len, true);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = file_in->f_op->remap_file_range(file_in, pos_in,
|
|
file_out, pos_out, len, remap_flags);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
fsnotify_access(file_in);
|
|
fsnotify_modify(file_out);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(do_clone_file_range);
|
|
|
|
loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
|
|
struct file *file_out, loff_t pos_out,
|
|
loff_t len, unsigned int remap_flags)
|
|
{
|
|
loff_t ret;
|
|
|
|
file_start_write(file_out);
|
|
ret = do_clone_file_range(file_in, pos_in, file_out, pos_out, len,
|
|
remap_flags);
|
|
file_end_write(file_out);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(vfs_clone_file_range);
|
|
|
|
/* Check whether we are allowed to dedupe the destination file */
|
|
static bool allow_file_dedupe(struct file *file)
|
|
{
|
|
if (capable(CAP_SYS_ADMIN))
|
|
return true;
|
|
if (file->f_mode & FMODE_WRITE)
|
|
return true;
|
|
if (uid_eq(current_fsuid(), file_inode(file)->i_uid))
|
|
return true;
|
|
if (!inode_permission(file_inode(file), MAY_WRITE))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
|
|
struct file *dst_file, loff_t dst_pos,
|
|
loff_t len, unsigned int remap_flags)
|
|
{
|
|
loff_t ret;
|
|
|
|
WARN_ON_ONCE(remap_flags & ~(REMAP_FILE_DEDUP |
|
|
REMAP_FILE_CAN_SHORTEN));
|
|
|
|
ret = mnt_want_write_file(dst_file);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = remap_verify_area(dst_file, dst_pos, len, true);
|
|
if (ret < 0)
|
|
goto out_drop_write;
|
|
|
|
ret = -EPERM;
|
|
if (!allow_file_dedupe(dst_file))
|
|
goto out_drop_write;
|
|
|
|
ret = -EXDEV;
|
|
if (src_file->f_path.mnt != dst_file->f_path.mnt)
|
|
goto out_drop_write;
|
|
|
|
ret = -EISDIR;
|
|
if (S_ISDIR(file_inode(dst_file)->i_mode))
|
|
goto out_drop_write;
|
|
|
|
ret = -EINVAL;
|
|
if (!dst_file->f_op->remap_file_range)
|
|
goto out_drop_write;
|
|
|
|
if (len == 0) {
|
|
ret = 0;
|
|
goto out_drop_write;
|
|
}
|
|
|
|
ret = dst_file->f_op->remap_file_range(src_file, src_pos, dst_file,
|
|
dst_pos, len, remap_flags | REMAP_FILE_DEDUP);
|
|
out_drop_write:
|
|
mnt_drop_write_file(dst_file);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(vfs_dedupe_file_range_one);
|
|
|
|
int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
|
|
{
|
|
struct file_dedupe_range_info *info;
|
|
struct inode *src = file_inode(file);
|
|
u64 off;
|
|
u64 len;
|
|
int i;
|
|
int ret;
|
|
u16 count = same->dest_count;
|
|
loff_t deduped;
|
|
|
|
if (!(file->f_mode & FMODE_READ))
|
|
return -EINVAL;
|
|
|
|
if (same->reserved1 || same->reserved2)
|
|
return -EINVAL;
|
|
|
|
off = same->src_offset;
|
|
len = same->src_length;
|
|
|
|
if (S_ISDIR(src->i_mode))
|
|
return -EISDIR;
|
|
|
|
if (!S_ISREG(src->i_mode))
|
|
return -EINVAL;
|
|
|
|
if (!file->f_op->remap_file_range)
|
|
return -EOPNOTSUPP;
|
|
|
|
ret = remap_verify_area(file, off, len, false);
|
|
if (ret < 0)
|
|
return ret;
|
|
ret = 0;
|
|
|
|
if (off + len > i_size_read(src))
|
|
return -EINVAL;
|
|
|
|
/* Arbitrary 1G limit on a single dedupe request, can be raised. */
|
|
len = min_t(u64, len, 1 << 30);
|
|
|
|
/* pre-format output fields to sane values */
|
|
for (i = 0; i < count; i++) {
|
|
same->info[i].bytes_deduped = 0ULL;
|
|
same->info[i].status = FILE_DEDUPE_RANGE_SAME;
|
|
}
|
|
|
|
for (i = 0, info = same->info; i < count; i++, info++) {
|
|
struct fd dst_fd = fdget(info->dest_fd);
|
|
struct file *dst_file = dst_fd.file;
|
|
|
|
if (!dst_file) {
|
|
info->status = -EBADF;
|
|
goto next_loop;
|
|
}
|
|
|
|
if (info->reserved) {
|
|
info->status = -EINVAL;
|
|
goto next_fdput;
|
|
}
|
|
|
|
deduped = vfs_dedupe_file_range_one(file, off, dst_file,
|
|
info->dest_offset, len,
|
|
REMAP_FILE_CAN_SHORTEN);
|
|
if (deduped == -EBADE)
|
|
info->status = FILE_DEDUPE_RANGE_DIFFERS;
|
|
else if (deduped < 0)
|
|
info->status = deduped;
|
|
else
|
|
info->bytes_deduped = len;
|
|
|
|
next_fdput:
|
|
fdput(dst_fd);
|
|
next_loop:
|
|
if (fatal_signal_pending(current))
|
|
break;
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(vfs_dedupe_file_range);
|