2 * linux/fs/read_write.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/slab.h>
8 #include <linux/stat.h>
9 #include <linux/fcntl.h>
10 #include <linux/file.h>
11 #include <linux/uio.h>
12 #include <linux/fsnotify.h>
13 #include <linux/security.h>
14 #include <linux/export.h>
15 #include <linux/syscalls.h>
16 #include <linux/pagemap.h>
17 #include <linux/splice.h>
18 #include <linux/compat.h>
21 #include <asm/uaccess.h>
22 #include <asm/unistd.h>
24 typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);
25 typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *);
27 const struct file_operations generic_ro_fops = {
28 .llseek = generic_file_llseek,
29 .read_iter = generic_file_read_iter,
30 .mmap = generic_file_readonly_mmap,
31 .splice_read = generic_file_splice_read,
34 EXPORT_SYMBOL(generic_ro_fops);
36 static inline int unsigned_offsets(struct file *file)
38 return file->f_mode & FMODE_UNSIGNED_OFFSET;
42 * vfs_setpos - update the file offset for lseek
43 * @file: file structure in question
44 * @offset: file offset to seek to
45 * @maxsize: maximum file size
47 * This is a low-level filesystem helper for updating the file offset to
48 * the value specified by @offset if the given offset is valid and it is
49 * not equal to the current file offset.
51 * Return the specified offset on success and -EINVAL on invalid offset.
53 loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)
55 if (offset < 0 && !unsigned_offsets(file))
60 if (offset != file->f_pos) {
66 EXPORT_SYMBOL(vfs_setpos);
69 * generic_file_llseek_size - generic llseek implementation for regular files
70 * @file: file structure to seek on
71 * @offset: file offset to seek to
72 * @whence: type of seek
73 * @size: max size of this file in file system
74 * @eof: offset used for SEEK_END position
76 * This is a variant of generic_file_llseek that allows passing in a custom
77 * maximum file size and a custom EOF position, for e.g. hashed directories
80 * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms)
81 * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes.
82 * read/writes behave like SEEK_SET against seeks.
85 generic_file_llseek_size(struct file *file, loff_t offset, int whence,
86 loff_t maxsize, loff_t eof)
94 * Here we special-case the lseek(fd, 0, SEEK_CUR)
95 * position-querying operation. Avoid rewriting the "same"
96 * f_pos value back to the file because a concurrent read(),
97 * write() or lseek() might have altered it
102 * f_lock protects against read/modify/write race with other
103 * SEEK_CURs. Note that parallel writes and reads behave
106 spin_lock(&file->f_lock);
107 offset = vfs_setpos(file, file->f_pos + offset, maxsize);
108 spin_unlock(&file->f_lock);
112 * In the generic case the entire file is data, so as long as
113 * offset isn't at the end of the file then the offset is data.
115 if ((unsigned long long)offset >= eof)
120 * There is a virtual hole at the end of the file, so as long as
121 * offset isn't i_size or larger, return i_size.
123 if ((unsigned long long)offset >= eof)
129 return vfs_setpos(file, offset, maxsize);
131 EXPORT_SYMBOL(generic_file_llseek_size);
134 * generic_file_llseek - generic llseek implementation for regular files
135 * @file: file structure to seek on
136 * @offset: file offset to seek to
137 * @whence: type of seek
139 * This is a generic implemenation of ->llseek useable for all normal local
140 * filesystems. It just updates the file offset to the value specified by
141 * @offset and @whence.
143 loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)
145 struct inode *inode = file->f_mapping->host;
147 return generic_file_llseek_size(file, offset, whence,
148 inode->i_sb->s_maxbytes,
151 EXPORT_SYMBOL(generic_file_llseek);
154 * fixed_size_llseek - llseek implementation for fixed-sized devices
155 * @file: file structure to seek on
156 * @offset: file offset to seek to
157 * @whence: type of seek
158 * @size: size of the file
161 loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)
164 case SEEK_SET: case SEEK_CUR: case SEEK_END:
165 return generic_file_llseek_size(file, offset, whence,
171 EXPORT_SYMBOL(fixed_size_llseek);
174 * noop_llseek - No Operation Performed llseek implementation
175 * @file: file structure to seek on
176 * @offset: file offset to seek to
177 * @whence: type of seek
179 * This is an implementation of ->llseek useable for the rare special case when
180 * userspace expects the seek to succeed but the (device) file is actually not
181 * able to perform the seek. In this case you use noop_llseek() instead of
182 * falling back to the default implementation of ->llseek.
184 loff_t noop_llseek(struct file *file, loff_t offset, int whence)
188 EXPORT_SYMBOL(noop_llseek);
190 loff_t no_llseek(struct file *file, loff_t offset, int whence)
194 EXPORT_SYMBOL(no_llseek);
196 loff_t default_llseek(struct file *file, loff_t offset, int whence)
198 struct inode *inode = file_inode(file);
201 mutex_lock(&inode->i_mutex);
204 offset += i_size_read(inode);
208 retval = file->f_pos;
211 offset += file->f_pos;
215 * In the generic case the entire file is data, so as
216 * long as offset isn't at the end of the file then the
219 if (offset >= inode->i_size) {
226 * There is a virtual hole at the end of the file, so
227 * as long as offset isn't i_size or larger, return
230 if (offset >= inode->i_size) {
234 offset = inode->i_size;
238 if (offset >= 0 || unsigned_offsets(file)) {
239 if (offset != file->f_pos) {
240 file->f_pos = offset;
246 mutex_unlock(&inode->i_mutex);
249 EXPORT_SYMBOL(default_llseek);
251 loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
253 loff_t (*fn)(struct file *, loff_t, int);
256 if (file->f_mode & FMODE_LSEEK) {
257 if (file->f_op->llseek)
258 fn = file->f_op->llseek;
260 return fn(file, offset, whence);
262 EXPORT_SYMBOL(vfs_llseek);
264 static inline struct fd fdget_pos(int fd)
266 return __to_fd(__fdget_pos(fd));
269 static inline void fdput_pos(struct fd f)
271 if (f.flags & FDPUT_POS_UNLOCK)
272 mutex_unlock(&f.file->f_pos_lock);
276 SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
279 struct fd f = fdget_pos(fd);
284 if (whence <= SEEK_MAX) {
285 loff_t res = vfs_llseek(f.file, offset, whence);
287 if (res != (loff_t)retval)
288 retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */
295 COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
297 return sys_lseek(fd, offset, whence);
301 #ifdef __ARCH_WANT_SYS_LLSEEK
302 SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
303 unsigned long, offset_low, loff_t __user *, result,
304 unsigned int, whence)
307 struct fd f = fdget_pos(fd);
314 if (whence > SEEK_MAX)
317 offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
320 retval = (int)offset;
323 if (!copy_to_user(result, &offset, sizeof(offset)))
332 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos)
337 if (!file->f_op->read_iter)
340 init_sync_kiocb(&kiocb, file);
341 kiocb.ki_pos = *ppos;
344 ret = file->f_op->read_iter(&kiocb, iter);
345 BUG_ON(ret == -EIOCBQUEUED);
347 *ppos = kiocb.ki_pos;
350 EXPORT_SYMBOL(vfs_iter_read);
352 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
357 if (!file->f_op->write_iter)
360 init_sync_kiocb(&kiocb, file);
361 kiocb.ki_pos = *ppos;
364 ret = file->f_op->write_iter(&kiocb, iter);
365 BUG_ON(ret == -EIOCBQUEUED);
367 *ppos = kiocb.ki_pos;
368 fsnotify_modify(file);
372 EXPORT_SYMBOL(vfs_iter_write);
375 * rw_verify_area doesn't like huge counts. We limit
376 * them to something that fits in "int" so that others
377 * won't have to do range checks all the time.
379 int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
383 int retval = -EINVAL;
385 inode = file_inode(file);
386 if (unlikely((ssize_t) count < 0))
389 if (unlikely(pos < 0)) {
390 if (!unsigned_offsets(file))
392 if (count >= -pos) /* both values are in 0..LLONG_MAX */
394 } else if (unlikely((loff_t) (pos + count) < 0)) {
395 if (!unsigned_offsets(file))
399 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
400 retval = locks_mandatory_area(
401 read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,
402 inode, file, pos, count);
406 retval = security_file_permission(file,
407 read_write == READ ? MAY_READ : MAY_WRITE);
410 return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
413 static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
415 struct iovec iov = { .iov_base = buf, .iov_len = len };
417 struct iov_iter iter;
420 init_sync_kiocb(&kiocb, filp);
421 kiocb.ki_pos = *ppos;
422 iov_iter_init(&iter, READ, &iov, 1, len);
424 ret = filp->f_op->read_iter(&kiocb, &iter);
425 BUG_ON(ret == -EIOCBQUEUED);
426 *ppos = kiocb.ki_pos;
430 ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
433 if (file->f_op->read)
434 return file->f_op->read(file, buf, count, pos);
435 else if (file->f_op->read_iter)
436 return new_sync_read(file, buf, count, pos);
440 EXPORT_SYMBOL(__vfs_read);
442 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
446 if (!(file->f_mode & FMODE_READ))
448 if (!(file->f_mode & FMODE_CAN_READ))
450 if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
453 ret = rw_verify_area(READ, file, pos, count);
456 ret = __vfs_read(file, buf, count, pos);
458 fsnotify_access(file);
459 add_rchar(current, ret);
467 EXPORT_SYMBOL(vfs_read);
469 static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
471 struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
473 struct iov_iter iter;
476 init_sync_kiocb(&kiocb, filp);
477 kiocb.ki_pos = *ppos;
478 iov_iter_init(&iter, WRITE, &iov, 1, len);
480 ret = filp->f_op->write_iter(&kiocb, &iter);
481 BUG_ON(ret == -EIOCBQUEUED);
483 *ppos = kiocb.ki_pos;
487 ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
490 if (file->f_op->write)
491 return file->f_op->write(file, p, count, pos);
492 else if (file->f_op->write_iter)
493 return new_sync_write(file, p, count, pos);
497 EXPORT_SYMBOL(__vfs_write);
499 ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
502 const char __user *p;
505 if (!(file->f_mode & FMODE_CAN_WRITE))
510 p = (__force const char __user *)buf;
511 if (count > MAX_RW_COUNT)
512 count = MAX_RW_COUNT;
513 ret = __vfs_write(file, p, count, pos);
516 fsnotify_modify(file);
517 add_wchar(current, ret);
523 EXPORT_SYMBOL(__kernel_write);
525 ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
529 if (!(file->f_mode & FMODE_WRITE))
531 if (!(file->f_mode & FMODE_CAN_WRITE))
533 if (unlikely(!access_ok(VERIFY_READ, buf, count)))
536 ret = rw_verify_area(WRITE, file, pos, count);
539 file_start_write(file);
540 ret = __vfs_write(file, buf, count, pos);
542 fsnotify_modify(file);
543 add_wchar(current, ret);
546 file_end_write(file);
552 EXPORT_SYMBOL(vfs_write);
554 static inline loff_t file_pos_read(struct file *file)
556 return file->f_mode & FMODE_STREAM ? 0 : file->f_pos;
559 static inline void file_pos_write(struct file *file, loff_t pos)
561 if ((file->f_mode & FMODE_STREAM) == 0)
565 SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
567 struct fd f = fdget_pos(fd);
568 ssize_t ret = -EBADF;
571 loff_t pos = file_pos_read(f.file);
572 ret = vfs_read(f.file, buf, count, &pos);
574 file_pos_write(f.file, pos);
580 SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
583 struct fd f = fdget_pos(fd);
584 ssize_t ret = -EBADF;
587 loff_t pos = file_pos_read(f.file);
588 ret = vfs_write(f.file, buf, count, &pos);
590 file_pos_write(f.file, pos);
597 SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
598 size_t, count, loff_t, pos)
601 ssize_t ret = -EBADF;
609 if (f.file->f_mode & FMODE_PREAD)
610 ret = vfs_read(f.file, buf, count, &pos);
617 SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
618 size_t, count, loff_t, pos)
621 ssize_t ret = -EBADF;
629 if (f.file->f_mode & FMODE_PWRITE)
630 ret = vfs_write(f.file, buf, count, &pos);
638 * Reduce an iovec's length in-place. Return the resulting number of segments
640 unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
642 unsigned long seg = 0;
645 while (seg < nr_segs) {
647 if (len + iov->iov_len >= to) {
648 iov->iov_len = to - len;
656 EXPORT_SYMBOL(iov_shorten);
658 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
659 loff_t *ppos, iter_fn_t fn)
664 init_sync_kiocb(&kiocb, filp);
665 kiocb.ki_pos = *ppos;
667 ret = fn(&kiocb, iter);
668 BUG_ON(ret == -EIOCBQUEUED);
669 *ppos = kiocb.ki_pos;
673 /* Do it by hand, with file-ops */
674 static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
675 loff_t *ppos, io_fn_t fn)
679 while (iov_iter_count(iter)) {
680 struct iovec iovec = iov_iter_iovec(iter);
683 nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos);
691 if (nr != iovec.iov_len)
693 iov_iter_advance(iter, nr);
699 /* A write operation does a read from user space and vice versa */
700 #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
702 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
703 unsigned long nr_segs, unsigned long fast_segs,
704 struct iovec *fast_pointer,
705 struct iovec **ret_pointer)
709 struct iovec *iov = fast_pointer;
712 * SuS says "The readv() function *may* fail if the iovcnt argument
713 * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
714 * traditionally returned zero for zero segments, so...
722 * First get the "struct iovec" from user memory and
723 * verify all the pointers
725 if (nr_segs > UIO_MAXIOV) {
729 if (nr_segs > fast_segs) {
730 iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
736 if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
742 * According to the Single Unix Specification we should return EINVAL
743 * if an element length is < 0 when cast to ssize_t or if the
744 * total length would overflow the ssize_t return value of the
747 * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
751 for (seg = 0; seg < nr_segs; seg++) {
752 void __user *buf = iov[seg].iov_base;
753 ssize_t len = (ssize_t)iov[seg].iov_len;
755 /* see if we we're about to use an invalid len or if
756 * it's about to overflow ssize_t */
762 && unlikely(!access_ok(vrfy_dir(type), buf, len))) {
766 if (len > MAX_RW_COUNT - ret) {
767 len = MAX_RW_COUNT - ret;
768 iov[seg].iov_len = len;
777 static ssize_t do_readv_writev(int type, struct file *file,
778 const struct iovec __user * uvector,
779 unsigned long nr_segs, loff_t *pos)
782 struct iovec iovstack[UIO_FASTIOV];
783 struct iovec *iov = iovstack;
784 struct iov_iter iter;
789 ret = import_iovec(type, uvector, nr_segs,
790 ARRAY_SIZE(iovstack), &iov, &iter);
794 tot_len = iov_iter_count(&iter);
797 ret = rw_verify_area(type, file, pos, tot_len);
802 fn = file->f_op->read;
803 iter_fn = file->f_op->read_iter;
805 fn = (io_fn_t)file->f_op->write;
806 iter_fn = file->f_op->write_iter;
807 file_start_write(file);
811 ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
813 ret = do_loop_readv_writev(file, &iter, pos, fn);
816 file_end_write(file);
820 if ((ret + (type == READ)) > 0) {
822 fsnotify_access(file);
824 fsnotify_modify(file);
829 ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
830 unsigned long vlen, loff_t *pos)
832 if (!(file->f_mode & FMODE_READ))
834 if (!(file->f_mode & FMODE_CAN_READ))
837 return do_readv_writev(READ, file, vec, vlen, pos);
840 EXPORT_SYMBOL(vfs_readv);
842 ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
843 unsigned long vlen, loff_t *pos)
845 if (!(file->f_mode & FMODE_WRITE))
847 if (!(file->f_mode & FMODE_CAN_WRITE))
850 return do_readv_writev(WRITE, file, vec, vlen, pos);
853 EXPORT_SYMBOL(vfs_writev);
855 SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
858 struct fd f = fdget_pos(fd);
859 ssize_t ret = -EBADF;
862 loff_t pos = file_pos_read(f.file);
863 ret = vfs_readv(f.file, vec, vlen, &pos);
865 file_pos_write(f.file, pos);
870 add_rchar(current, ret);
875 SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
878 struct fd f = fdget_pos(fd);
879 ssize_t ret = -EBADF;
882 loff_t pos = file_pos_read(f.file);
883 ret = vfs_writev(f.file, vec, vlen, &pos);
885 file_pos_write(f.file, pos);
890 add_wchar(current, ret);
895 static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
897 #define HALF_LONG_BITS (BITS_PER_LONG / 2)
898 return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
901 SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
902 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
904 loff_t pos = pos_from_hilo(pos_h, pos_l);
906 ssize_t ret = -EBADF;
914 if (f.file->f_mode & FMODE_PREAD)
915 ret = vfs_readv(f.file, vec, vlen, &pos);
920 add_rchar(current, ret);
925 SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
926 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
928 loff_t pos = pos_from_hilo(pos_h, pos_l);
930 ssize_t ret = -EBADF;
938 if (f.file->f_mode & FMODE_PWRITE)
939 ret = vfs_writev(f.file, vec, vlen, &pos);
944 add_wchar(current, ret);
951 static ssize_t compat_do_readv_writev(int type, struct file *file,
952 const struct compat_iovec __user *uvector,
953 unsigned long nr_segs, loff_t *pos)
955 compat_ssize_t tot_len;
956 struct iovec iovstack[UIO_FASTIOV];
957 struct iovec *iov = iovstack;
958 struct iov_iter iter;
963 ret = compat_import_iovec(type, uvector, nr_segs,
964 UIO_FASTIOV, &iov, &iter);
968 tot_len = iov_iter_count(&iter);
971 ret = rw_verify_area(type, file, pos, tot_len);
976 fn = file->f_op->read;
977 iter_fn = file->f_op->read_iter;
979 fn = (io_fn_t)file->f_op->write;
980 iter_fn = file->f_op->write_iter;
981 file_start_write(file);
985 ret = do_iter_readv_writev(file, &iter, pos, iter_fn);
987 ret = do_loop_readv_writev(file, &iter, pos, fn);
990 file_end_write(file);
994 if ((ret + (type == READ)) > 0) {
996 fsnotify_access(file);
998 fsnotify_modify(file);
1003 static size_t compat_readv(struct file *file,
1004 const struct compat_iovec __user *vec,
1005 unsigned long vlen, loff_t *pos)
1007 ssize_t ret = -EBADF;
1009 if (!(file->f_mode & FMODE_READ))
1013 if (!(file->f_mode & FMODE_CAN_READ))
1016 ret = compat_do_readv_writev(READ, file, vec, vlen, pos);
1020 add_rchar(current, ret);
1025 COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
1026 const struct compat_iovec __user *,vec,
1027 compat_ulong_t, vlen)
1029 struct fd f = fdget_pos(fd);
1035 pos = f.file->f_pos;
1036 ret = compat_readv(f.file, vec, vlen, &pos);
1038 f.file->f_pos = pos;
1043 static long __compat_sys_preadv64(unsigned long fd,
1044 const struct compat_iovec __user *vec,
1045 unsigned long vlen, loff_t pos)
1056 if (f.file->f_mode & FMODE_PREAD)
1057 ret = compat_readv(f.file, vec, vlen, &pos);
1062 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
1063 COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
1064 const struct compat_iovec __user *,vec,
1065 unsigned long, vlen, loff_t, pos)
1067 return __compat_sys_preadv64(fd, vec, vlen, pos);
1071 COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
1072 const struct compat_iovec __user *,vec,
1073 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1075 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1077 return __compat_sys_preadv64(fd, vec, vlen, pos);
1080 static size_t compat_writev(struct file *file,
1081 const struct compat_iovec __user *vec,
1082 unsigned long vlen, loff_t *pos)
1084 ssize_t ret = -EBADF;
1086 if (!(file->f_mode & FMODE_WRITE))
1090 if (!(file->f_mode & FMODE_CAN_WRITE))
1093 ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos);
1097 add_wchar(current, ret);
1102 COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
1103 const struct compat_iovec __user *, vec,
1104 compat_ulong_t, vlen)
1106 struct fd f = fdget_pos(fd);
1112 pos = f.file->f_pos;
1113 ret = compat_writev(f.file, vec, vlen, &pos);
1115 f.file->f_pos = pos;
1120 static long __compat_sys_pwritev64(unsigned long fd,
1121 const struct compat_iovec __user *vec,
1122 unsigned long vlen, loff_t pos)
1133 if (f.file->f_mode & FMODE_PWRITE)
1134 ret = compat_writev(f.file, vec, vlen, &pos);
1139 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
1140 COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
1141 const struct compat_iovec __user *,vec,
1142 unsigned long, vlen, loff_t, pos)
1144 return __compat_sys_pwritev64(fd, vec, vlen, pos);
1148 COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
1149 const struct compat_iovec __user *,vec,
1150 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1152 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1154 return __compat_sys_pwritev64(fd, vec, vlen, pos);
1158 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
1159 size_t count, loff_t max)
1162 struct inode *in_inode, *out_inode;
1169 * Get input file, and verify that it is ok..
1175 if (!(in.file->f_mode & FMODE_READ))
1179 pos = in.file->f_pos;
1182 if (!(in.file->f_mode & FMODE_PREAD))
1185 retval = rw_verify_area(READ, in.file, &pos, count);
1191 * Get output file, and verify that it is ok..
1194 out = fdget(out_fd);
1197 if (!(out.file->f_mode & FMODE_WRITE))
1200 in_inode = file_inode(in.file);
1201 out_inode = file_inode(out.file);
1202 out_pos = out.file->f_pos;
1203 retval = rw_verify_area(WRITE, out.file, &out_pos, count);
1209 max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
1211 if (unlikely(pos + count > max)) {
1212 retval = -EOVERFLOW;
1221 * We need to debate whether we can enable this or not. The
1222 * man page documents EAGAIN return for the output at least,
1223 * and the application is arguably buggy if it doesn't expect
1224 * EAGAIN on a non-blocking file descriptor.
1226 if (in.file->f_flags & O_NONBLOCK)
1227 fl = SPLICE_F_NONBLOCK;
1229 file_start_write(out.file);
1230 retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
1231 file_end_write(out.file);
1234 add_rchar(current, retval);
1235 add_wchar(current, retval);
1236 fsnotify_access(in.file);
1237 fsnotify_modify(out.file);
1238 out.file->f_pos = out_pos;
1242 in.file->f_pos = pos;
1248 retval = -EOVERFLOW;
1258 SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
1265 if (unlikely(get_user(off, offset)))
1268 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1269 if (unlikely(put_user(pos, offset)))
1274 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1277 SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
1283 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1285 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1286 if (unlikely(put_user(pos, offset)))
1291 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1294 #ifdef CONFIG_COMPAT
1295 COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
1296 compat_off_t __user *, offset, compat_size_t, count)
1303 if (unlikely(get_user(off, offset)))
1306 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1307 if (unlikely(put_user(pos, offset)))
1312 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1315 COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
1316 compat_loff_t __user *, offset, compat_size_t, count)
1322 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1324 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1325 if (unlikely(put_user(pos, offset)))
1330 return do_sendfile(out_fd, in_fd, NULL, count, 0);