| // 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); |
| |
| SYSCALL_DEFINE3(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; |
| } |
| |
| #ifdef CONFIG_COMPAT |
| COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence) |
| { |
| return sys_lseek(fd, offset, whence); |
| } |
| #endif |
| |
| #ifdef __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; |
| loff_t pos; |
| int retval = -EINVAL; |
| |
| inode = file_inode(file); |
| if (unlikely((ssize_t) count < 0)) |
| return retval; |
| 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; |
| iov_iter_init(&iter, READ, &iov, 1, len); |
| |
| ret = call_read_iter(filp, &kiocb, &iter); |
| BUG_ON(ret == -EIOCBQUEUED); |
| *ppos = kiocb.ki_pos; |
| return ret; |
| } |
| |
| ssize_t __vfs_read(struct file *file, char __user *buf, size_t count, |
| loff_t *pos) |
| { |
| if (file->f_op->read) |
| return file->f_op->read(file, buf, count, pos); |
| else if (file->f_op->read_iter) |
| return new_sync_read(file, buf, count, pos); |
| else |
| return -EINVAL; |
| } |
| |
| ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) |
| { |
| mm_segment_t old_fs; |
| ssize_t result; |
| |
| old_fs = get_fs(); |
| set_fs(get_ds()); |
| /* The cast to a user pointer is valid due to the set_fs() */ |
| result = vfs_read(file, (void __user *)buf, count, pos); |
| set_fs(old_fs); |
| return result; |
| } |
| EXPORT_SYMBOL(kernel_read); |
| |
| ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) |
| { |
| ssize_t ret; |
| |
| if (!(file->f_mode & FMODE_READ)) |
| return -EBADF; |
| if (!(file->f_mode & FMODE_CAN_READ)) |
| return -EINVAL; |
| if (unlikely(!access_ok(VERIFY_WRITE, 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; |
| } |
| |
| EXPORT_SYMBOL(vfs_read); |
| |
| 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; |
| iov_iter_init(&iter, WRITE, &iov, 1, len); |
| |
| ret = call_write_iter(filp, &kiocb, &iter); |
| BUG_ON(ret == -EIOCBQUEUED); |
| if (ret > 0) |
| *ppos = kiocb.ki_pos; |
| return ret; |
| } |
| |
| 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(get_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(get_ds()); |
| /* The cast to a user pointer is valid due to the set_fs() */ |
| res = vfs_write(file, (__force const char __user *)buf, count, pos); |
| set_fs(old_fs); |
| |
| return res; |
| } |
| EXPORT_SYMBOL(kernel_write); |
| |
| ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) |
| { |
| ssize_t ret; |
| |
| if (!(file->f_mode & FMODE_WRITE)) |
| return -EBADF; |
| if (!(file->f_mode & FMODE_CAN_WRITE)) |
| return -EINVAL; |
| if (unlikely(!access_ok(VERIFY_READ, 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; |
| } |
| |
| EXPORT_SYMBOL(vfs_write); |
| |
| static inline loff_t file_pos_read(struct file *file) |
| { |
| return file->f_mode & FMODE_STREAM ? 0 : file->f_pos; |
| } |
| |
| static inline void file_pos_write(struct file *file, loff_t pos) |
| { |
| if ((file->f_mode & FMODE_STREAM) == 0) |
| file->f_pos = pos; |
| } |
| |
| SYSCALL_DEFINE3(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 = file_pos_read(f.file); |
| ret = vfs_read(f.file, buf, count, &pos); |
| if (ret >= 0) |
| file_pos_write(f.file, pos); |
| fdput_pos(f); |
| } |
| return ret; |
| } |
| |
| SYSCALL_DEFINE3(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 = file_pos_read(f.file); |
| ret = vfs_write(f.file, buf, count, &pos); |
| if (ret >= 0) |
| file_pos_write(f.file, pos); |
| fdput_pos(f); |
| } |
| |
| return ret; |
| } |
| |
| SYSCALL_DEFINE4(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(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; |
| } |
| |
| /* |
| * Reduce an iovec's length in-place. Return the resulting number of segments |
| */ |
| unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to) |
| { |
| unsigned long seg = 0; |
| size_t len = 0; |
| |
| while (seg < nr_segs) { |
| seg++; |
| if (len + iov->iov_len >= to) { |
| iov->iov_len = to - len; |
| break; |
| } |
| len += iov->iov_len; |
| iov++; |
| } |
| return seg; |
| } |
| EXPORT_SYMBOL(iov_shorten); |
| |
| 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; |
| |
| if (type == READ) |
| ret = call_read_iter(filp, &kiocb, iter); |
| else |
| ret = call_write_iter(filp, &kiocb, iter); |
| BUG_ON(ret == -EIOCBQUEUED); |
| *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; |
| } |
| |
| /* A write operation does a read from user space and vice versa */ |
| #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) |
| |
| /** |
| * 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(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(vrfy_dir(type), 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(nr_segs*sizeof(struct iovec), GFP_KERNEL); |
| if (iov == NULL) |
| goto out; |
| } |
| *ret_pointer = iov; |
| |
| ret = -EFAULT; |
| if (!access_ok(VERIFY_READ, 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(vrfy_dir(type), 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 = file_pos_read(f.file); |
| ret = vfs_readv(f.file, vec, vlen, &pos, flags); |
| if (ret >= 0) |
| file_pos_write(f.file, 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 = file_pos_read(f.file); |
| ret = vfs_writev(f.file, vec, vlen, &pos, flags); |
| if (ret >= 0) |
| file_pos_write(f.file, 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; |
| retval = -EINVAL; |
| 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 |
| |
| /* |
| * 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) |
| { |
| struct inode *inode_in = file_inode(file_in); |
| struct inode *inode_out = file_inode(file_out); |
| ssize_t ret; |
| |
| if (flags != 0) |
| return -EINVAL; |
| |
| 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; |
| |
| 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 (!(file_in->f_mode & FMODE_READ) || |
| !(file_out->f_mode & FMODE_WRITE) || |
| (file_out->f_flags & O_APPEND)) |
| return -EBADF; |
| |
| /* this could be relaxed once a method supports cross-fs copies */ |
| if (inode_in->i_sb != inode_out->i_sb) |
| return -EXDEV; |
| |
| 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->clone_file_range) { |
| ret = file_in->f_op->clone_file_range(file_in, pos_in, |
| file_out, pos_out, len); |
| if (ret == 0) { |
| ret = len; |
| goto done; |
| } |
| } |
| |
| if (file_out->f_op->copy_file_range) { |
| ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, |
| pos_out, len, flags); |
| if (ret != -EOPNOTSUPP) |
| goto done; |
| } |
| |
| ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, |
| len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); |
| |
| 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 clone_verify_area(struct file *file, loff_t pos, u64 len, bool write) |
| { |
| struct inode *inode = file_inode(file); |
| |
| if (unlikely(pos < 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); |
| } |
| |
| /* |
| * 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. |
| * |
| * Returns: 0 for "nothing to clone", 1 for "something to clone", or |
| * the usual negative error code. |
| */ |
| int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in, |
| struct inode *inode_out, loff_t pos_out, |
| u64 *len, bool is_dedupe) |
| { |
| loff_t bs = inode_out->i_sb->s_blocksize; |
| loff_t blen; |
| loff_t isize; |
| 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; |
| |
| /* Are we going all the way to the end? */ |
| isize = i_size_read(inode_in); |
| if (isize == 0) |
| return 0; |
| |
| /* Zero length dedupe exits immediately; reflink goes to EOF. */ |
| if (*len == 0) { |
| if (is_dedupe || pos_in == isize) |
| return 0; |
| if (pos_in > isize) |
| return -EINVAL; |
| *len = isize - pos_in; |
| } |
| |
| /* Ensure offsets don't wrap and the input is inside i_size */ |
| if (pos_in + *len < pos_in || pos_out + *len < pos_out || |
| pos_in + *len > isize) |
| return -EINVAL; |
| |
| /* Don't allow dedupe past EOF in the dest file */ |
| if (is_dedupe) { |
| loff_t disize; |
| |
| disize = i_size_read(inode_out); |
| if (pos_out >= disize || pos_out + *len > disize) |
| return -EINVAL; |
| } |
| |
| /* If we're linking to EOF, continue to the block boundary. */ |
| if (pos_in + *len == isize) |
| blen = ALIGN(isize, bs) - pos_in; |
| else |
| blen = *len; |
| |
| /* Only reflink if we're aligned to block boundaries */ |
| if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) || |
| !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs)) |
| return -EINVAL; |
| |
| /* Don't allow overlapped reflink within the same file */ |
| if (same_inode) { |
| if (pos_out + blen > pos_in && pos_out < pos_in + blen) |
| return -EINVAL; |
| } |
| |
| /* 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 (is_dedupe) { |
| 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; |
| } |
| |
| return 1; |
| } |
| EXPORT_SYMBOL(vfs_clone_file_prep_inodes); |
| |
| int do_clone_file_range(struct file *file_in, loff_t pos_in, |
| struct file *file_out, loff_t pos_out, u64 len) |
| { |
| struct inode *inode_in = file_inode(file_in); |
| struct inode *inode_out = file_inode(file_out); |
| int ret; |
| |
| 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; |
| |
| /* |
| * 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 (inode_in->i_sb != inode_out->i_sb) |
| return -EXDEV; |
| |
| if (!(file_in->f_mode & FMODE_READ) || |
| !(file_out->f_mode & FMODE_WRITE) || |
| (file_out->f_flags & O_APPEND)) |
| return -EBADF; |
| |
| if (!file_in->f_op->clone_file_range) |
| return -EOPNOTSUPP; |
| |
| ret = clone_verify_area(file_in, pos_in, len, false); |
| if (ret) |
| return ret; |
| |
| ret = clone_verify_area(file_out, pos_out, len, true); |
| if (ret) |
| return ret; |
| |
| if (pos_in + len > i_size_read(inode_in)) |
| return -EINVAL; |
| |
| ret = file_in->f_op->clone_file_range(file_in, pos_in, |
| file_out, pos_out, len); |
| if (!ret) { |
| fsnotify_access(file_in); |
| fsnotify_modify(file_out); |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(do_clone_file_range); |
| |
| int vfs_clone_file_range(struct file *file_in, loff_t pos_in, |
| struct file *file_out, loff_t pos_out, u64 len) |
| { |
| int ret; |
| |
| file_start_write(file_out); |
| ret = do_clone_file_range(file_in, pos_in, file_out, pos_out, len); |
| file_end_write(file_out); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(vfs_clone_file_range); |
| |
| /* 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 address_space *mapping; |
| struct page *page; |
| pgoff_t n; |
| |
| n = offset >> PAGE_SHIFT; |
| mapping = inode->i_mapping; |
| page = read_mapping_page(mapping, n, 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. |
| */ |
| 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; |
| } |
| EXPORT_SYMBOL(vfs_dedupe_file_range_compare); |
| |
| 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; |
| bool is_admin = capable(CAP_SYS_ADMIN); |
| u16 count = same->dest_count; |
| struct file *dst_file; |
| loff_t dst_off; |
| ssize_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; |
| |
| ret = -EISDIR; |
| if (S_ISDIR(src->i_mode)) |
| goto out; |
| |
| ret = -EINVAL; |
| if (!S_ISREG(src->i_mode)) |
| goto out; |
| |
| ret = clone_verify_area(file, off, len, false); |
| if (ret < 0) |
| goto out; |
| ret = 0; |
| |
| if (off + len > i_size_read(src)) |
| return -EINVAL; |
| |
| /* 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 inode *dst; |
| struct fd dst_fd = fdget(info->dest_fd); |
| |
| dst_file = dst_fd.file; |
| if (!dst_file) { |
| info->status = -EBADF; |
| goto next_loop; |
| } |
| dst = file_inode(dst_file); |
| |
| ret = mnt_want_write_file(dst_file); |
| if (ret) { |
| info->status = ret; |
| goto next_loop; |
| } |
| |
| dst_off = info->dest_offset; |
| ret = clone_verify_area(dst_file, dst_off, len, true); |
| if (ret < 0) { |
| info->status = ret; |
| goto next_file; |
| } |
| ret = 0; |
| |
| if (info->reserved) { |
| info->status = -EINVAL; |
| } else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) { |
| info->status = -EINVAL; |
| } else if (file->f_path.mnt != dst_file->f_path.mnt) { |
| info->status = -EXDEV; |
| } else if (S_ISDIR(dst->i_mode)) { |
| info->status = -EISDIR; |
| } else if (dst_file->f_op->dedupe_file_range == NULL) { |
| info->status = -EINVAL; |
| } else { |
| deduped = dst_file->f_op->dedupe_file_range(file, off, |
| len, dst_file, |
| info->dest_offset); |
| if (deduped == -EBADE) |
| info->status = FILE_DEDUPE_RANGE_DIFFERS; |
| else if (deduped < 0) |
| info->status = deduped; |
| else |
| info->bytes_deduped += deduped; |
| } |
| |
| next_file: |
| mnt_drop_write_file(dst_file); |
| next_loop: |
| fdput(dst_fd); |
| |
| if (fatal_signal_pending(current)) |
| goto out; |
| } |
| |
| out: |
| return ret; |
| } |
| EXPORT_SYMBOL(vfs_dedupe_file_range); |