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>
19 #include <linux/mount.h>
23 #include <asm/uaccess.h>
24 #include <asm/unistd.h>
26 typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);
27 typedef ssize_t (*iter_fn_t)(struct kiocb *, struct iov_iter *);
29 const struct file_operations generic_ro_fops = {
30 .llseek = generic_file_llseek,
31 .read_iter = generic_file_read_iter,
32 .mmap = generic_file_readonly_mmap,
33 .splice_read = generic_file_splice_read,
36 EXPORT_SYMBOL(generic_ro_fops);
38 static inline int unsigned_offsets(struct file *file)
40 return file->f_mode & FMODE_UNSIGNED_OFFSET;
44 * vfs_setpos - update the file offset for lseek
45 * @file: file structure in question
46 * @offset: file offset to seek to
47 * @maxsize: maximum file size
49 * This is a low-level filesystem helper for updating the file offset to
50 * the value specified by @offset if the given offset is valid and it is
51 * not equal to the current file offset.
53 * Return the specified offset on success and -EINVAL on invalid offset.
55 loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)
57 if (offset < 0 && !unsigned_offsets(file))
62 if (offset != file->f_pos) {
68 EXPORT_SYMBOL(vfs_setpos);
71 * generic_file_llseek_size - generic llseek implementation for regular files
72 * @file: file structure to seek on
73 * @offset: file offset to seek to
74 * @whence: type of seek
75 * @size: max size of this file in file system
76 * @eof: offset used for SEEK_END position
78 * This is a variant of generic_file_llseek that allows passing in a custom
79 * maximum file size and a custom EOF position, for e.g. hashed directories
82 * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms)
83 * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes.
84 * read/writes behave like SEEK_SET against seeks.
87 generic_file_llseek_size(struct file *file, loff_t offset, int whence,
88 loff_t maxsize, loff_t eof)
96 * Here we special-case the lseek(fd, 0, SEEK_CUR)
97 * position-querying operation. Avoid rewriting the "same"
98 * f_pos value back to the file because a concurrent read(),
99 * write() or lseek() might have altered it
104 * f_lock protects against read/modify/write race with other
105 * SEEK_CURs. Note that parallel writes and reads behave
108 spin_lock(&file->f_lock);
109 offset = vfs_setpos(file, file->f_pos + offset, maxsize);
110 spin_unlock(&file->f_lock);
114 * In the generic case the entire file is data, so as long as
115 * offset isn't at the end of the file then the offset is data.
117 if ((unsigned long long)offset >= eof)
122 * There is a virtual hole at the end of the file, so as long as
123 * offset isn't i_size or larger, return i_size.
125 if ((unsigned long long)offset >= eof)
131 return vfs_setpos(file, offset, maxsize);
133 EXPORT_SYMBOL(generic_file_llseek_size);
136 * generic_file_llseek - generic llseek implementation for regular files
137 * @file: file structure to seek on
138 * @offset: file offset to seek to
139 * @whence: type of seek
141 * This is a generic implemenation of ->llseek useable for all normal local
142 * filesystems. It just updates the file offset to the value specified by
143 * @offset and @whence.
145 loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)
147 struct inode *inode = file->f_mapping->host;
149 return generic_file_llseek_size(file, offset, whence,
150 inode->i_sb->s_maxbytes,
153 EXPORT_SYMBOL(generic_file_llseek);
156 * fixed_size_llseek - llseek implementation for fixed-sized devices
157 * @file: file structure to seek on
158 * @offset: file offset to seek to
159 * @whence: type of seek
160 * @size: size of the file
163 loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)
166 case SEEK_SET: case SEEK_CUR: case SEEK_END:
167 return generic_file_llseek_size(file, offset, whence,
173 EXPORT_SYMBOL(fixed_size_llseek);
176 * no_seek_end_llseek - llseek implementation for fixed-sized devices
177 * @file: file structure to seek on
178 * @offset: file offset to seek to
179 * @whence: type of seek
182 loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence)
185 case SEEK_SET: case SEEK_CUR:
186 return generic_file_llseek_size(file, offset, whence,
192 EXPORT_SYMBOL(no_seek_end_llseek);
195 * no_seek_end_llseek_size - llseek implementation for fixed-sized devices
196 * @file: file structure to seek on
197 * @offset: file offset to seek to
198 * @whence: type of seek
199 * @size: maximal offset allowed
202 loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size)
205 case SEEK_SET: case SEEK_CUR:
206 return generic_file_llseek_size(file, offset, whence,
212 EXPORT_SYMBOL(no_seek_end_llseek_size);
215 * noop_llseek - No Operation Performed llseek implementation
216 * @file: file structure to seek on
217 * @offset: file offset to seek to
218 * @whence: type of seek
220 * This is an implementation of ->llseek useable for the rare special case when
221 * userspace expects the seek to succeed but the (device) file is actually not
222 * able to perform the seek. In this case you use noop_llseek() instead of
223 * falling back to the default implementation of ->llseek.
225 loff_t noop_llseek(struct file *file, loff_t offset, int whence)
229 EXPORT_SYMBOL(noop_llseek);
231 loff_t no_llseek(struct file *file, loff_t offset, int whence)
235 EXPORT_SYMBOL(no_llseek);
237 loff_t default_llseek(struct file *file, loff_t offset, int whence)
239 struct inode *inode = file_inode(file);
245 offset += i_size_read(inode);
249 retval = file->f_pos;
252 offset += file->f_pos;
256 * In the generic case the entire file is data, so as
257 * long as offset isn't at the end of the file then the
260 if (offset >= inode->i_size) {
267 * There is a virtual hole at the end of the file, so
268 * as long as offset isn't i_size or larger, return
271 if (offset >= inode->i_size) {
275 offset = inode->i_size;
279 if (offset >= 0 || unsigned_offsets(file)) {
280 if (offset != file->f_pos) {
281 file->f_pos = offset;
290 EXPORT_SYMBOL(default_llseek);
292 loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
294 loff_t (*fn)(struct file *, loff_t, int);
297 if (file->f_mode & FMODE_LSEEK) {
298 if (file->f_op->llseek)
299 fn = file->f_op->llseek;
301 return fn(file, offset, whence);
303 EXPORT_SYMBOL(vfs_llseek);
305 SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
308 struct fd f = fdget_pos(fd);
313 if (whence <= SEEK_MAX) {
314 loff_t res = vfs_llseek(f.file, offset, whence);
316 if (res != (loff_t)retval)
317 retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */
324 COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
326 return sys_lseek(fd, offset, whence);
330 #ifdef __ARCH_WANT_SYS_LLSEEK
331 SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
332 unsigned long, offset_low, loff_t __user *, result,
333 unsigned int, whence)
336 struct fd f = fdget_pos(fd);
343 if (whence > SEEK_MAX)
346 offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
349 retval = (int)offset;
352 if (!copy_to_user(result, &offset, sizeof(offset)))
361 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos)
366 if (!file->f_op->read_iter)
369 init_sync_kiocb(&kiocb, file);
370 kiocb.ki_pos = *ppos;
373 ret = file->f_op->read_iter(&kiocb, iter);
374 BUG_ON(ret == -EIOCBQUEUED);
376 *ppos = kiocb.ki_pos;
379 EXPORT_SYMBOL(vfs_iter_read);
381 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
386 if (!file->f_op->write_iter)
389 init_sync_kiocb(&kiocb, file);
390 kiocb.ki_pos = *ppos;
393 ret = file->f_op->write_iter(&kiocb, iter);
394 BUG_ON(ret == -EIOCBQUEUED);
396 *ppos = kiocb.ki_pos;
397 fsnotify_modify(file);
401 EXPORT_SYMBOL(vfs_iter_write);
403 int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
407 int retval = -EINVAL;
409 inode = file_inode(file);
410 if (unlikely((ssize_t) count < 0))
413 if (unlikely(pos < 0)) {
414 if (!unsigned_offsets(file))
416 if (count >= -pos) /* both values are in 0..LLONG_MAX */
418 } else if (unlikely((loff_t) (pos + count) < 0)) {
419 if (!unsigned_offsets(file))
423 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
424 retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
425 read_write == READ ? F_RDLCK : F_WRLCK);
429 return security_file_permission(file,
430 read_write == READ ? MAY_READ : MAY_WRITE);
433 static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
435 struct iovec iov = { .iov_base = buf, .iov_len = len };
437 struct iov_iter iter;
440 init_sync_kiocb(&kiocb, filp);
441 kiocb.ki_pos = *ppos;
442 iov_iter_init(&iter, READ, &iov, 1, len);
444 ret = filp->f_op->read_iter(&kiocb, &iter);
445 BUG_ON(ret == -EIOCBQUEUED);
446 *ppos = kiocb.ki_pos;
450 ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
453 if (file->f_op->read)
454 return file->f_op->read(file, buf, count, pos);
455 else if (file->f_op->read_iter)
456 return new_sync_read(file, buf, count, pos);
460 EXPORT_SYMBOL(__vfs_read);
462 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
466 if (!(file->f_mode & FMODE_READ))
468 if (!(file->f_mode & FMODE_CAN_READ))
470 if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
473 ret = rw_verify_area(READ, file, pos, count);
475 if (count > MAX_RW_COUNT)
476 count = MAX_RW_COUNT;
477 ret = __vfs_read(file, buf, count, pos);
479 fsnotify_access(file);
480 add_rchar(current, ret);
488 EXPORT_SYMBOL(vfs_read);
490 static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
492 struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
494 struct iov_iter iter;
497 init_sync_kiocb(&kiocb, filp);
498 kiocb.ki_pos = *ppos;
499 iov_iter_init(&iter, WRITE, &iov, 1, len);
501 ret = filp->f_op->write_iter(&kiocb, &iter);
502 BUG_ON(ret == -EIOCBQUEUED);
504 *ppos = kiocb.ki_pos;
508 ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
511 if (file->f_op->write)
512 return file->f_op->write(file, p, count, pos);
513 else if (file->f_op->write_iter)
514 return new_sync_write(file, p, count, pos);
518 EXPORT_SYMBOL(__vfs_write);
520 ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
523 const char __user *p;
526 if (!(file->f_mode & FMODE_CAN_WRITE))
531 p = (__force const char __user *)buf;
532 if (count > MAX_RW_COUNT)
533 count = MAX_RW_COUNT;
534 ret = __vfs_write(file, p, count, pos);
537 fsnotify_modify(file);
538 add_wchar(current, ret);
544 EXPORT_SYMBOL(__kernel_write);
546 ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
550 if (!(file->f_mode & FMODE_WRITE))
552 if (!(file->f_mode & FMODE_CAN_WRITE))
554 if (unlikely(!access_ok(VERIFY_READ, buf, count)))
557 ret = rw_verify_area(WRITE, file, pos, count);
559 if (count > MAX_RW_COUNT)
560 count = MAX_RW_COUNT;
561 file_start_write(file);
562 ret = __vfs_write(file, buf, count, pos);
564 fsnotify_modify(file);
565 add_wchar(current, ret);
568 file_end_write(file);
574 EXPORT_SYMBOL(vfs_write);
576 static inline loff_t file_pos_read(struct file *file)
581 static inline void file_pos_write(struct file *file, loff_t pos)
586 SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
588 struct fd f = fdget_pos(fd);
589 ssize_t ret = -EBADF;
592 loff_t pos = file_pos_read(f.file);
593 ret = vfs_read(f.file, buf, count, &pos);
595 file_pos_write(f.file, pos);
601 SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
604 struct fd f = fdget_pos(fd);
605 ssize_t ret = -EBADF;
608 loff_t pos = file_pos_read(f.file);
609 ret = vfs_write(f.file, buf, count, &pos);
611 file_pos_write(f.file, pos);
618 SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
619 size_t, count, loff_t, pos)
622 ssize_t ret = -EBADF;
630 if (f.file->f_mode & FMODE_PREAD)
631 ret = vfs_read(f.file, buf, count, &pos);
638 SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
639 size_t, count, loff_t, pos)
642 ssize_t ret = -EBADF;
650 if (f.file->f_mode & FMODE_PWRITE)
651 ret = vfs_write(f.file, buf, count, &pos);
659 * Reduce an iovec's length in-place. Return the resulting number of segments
661 unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
663 unsigned long seg = 0;
666 while (seg < nr_segs) {
668 if (len + iov->iov_len >= to) {
669 iov->iov_len = to - len;
677 EXPORT_SYMBOL(iov_shorten);
679 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
680 loff_t *ppos, iter_fn_t fn, int flags)
685 if (flags & ~(RWF_HIPRI | RWF_DSYNC | RWF_SYNC))
688 init_sync_kiocb(&kiocb, filp);
689 if (flags & RWF_HIPRI)
690 kiocb.ki_flags |= IOCB_HIPRI;
691 if (flags & RWF_DSYNC)
692 kiocb.ki_flags |= IOCB_DSYNC;
693 if (flags & RWF_SYNC)
694 kiocb.ki_flags |= (IOCB_DSYNC | IOCB_SYNC);
695 kiocb.ki_pos = *ppos;
697 ret = fn(&kiocb, iter);
698 BUG_ON(ret == -EIOCBQUEUED);
699 *ppos = kiocb.ki_pos;
703 /* Do it by hand, with file-ops */
704 static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
705 loff_t *ppos, io_fn_t fn, int flags)
709 if (flags & ~RWF_HIPRI)
712 while (iov_iter_count(iter)) {
713 struct iovec iovec = iov_iter_iovec(iter);
716 nr = fn(filp, iovec.iov_base, iovec.iov_len, ppos);
724 if (nr != iovec.iov_len)
726 iov_iter_advance(iter, nr);
732 /* A write operation does a read from user space and vice versa */
733 #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
736 * rw_copy_check_uvector() - Copy an array of &struct iovec from userspace
737 * into the kernel and check that it is valid.
739 * @type: One of %CHECK_IOVEC_ONLY, %READ, or %WRITE.
740 * @uvector: Pointer to the userspace array.
741 * @nr_segs: Number of elements in userspace array.
742 * @fast_segs: Number of elements in @fast_pointer.
743 * @fast_pointer: Pointer to (usually small on-stack) kernel array.
744 * @ret_pointer: (output parameter) Pointer to a variable that will point to
745 * either @fast_pointer, a newly allocated kernel array, or NULL,
746 * depending on which array was used.
748 * This function copies an array of &struct iovec of @nr_segs from
749 * userspace into the kernel and checks that each element is valid (e.g.
750 * it does not point to a kernel address or cause overflow by being too
753 * As an optimization, the caller may provide a pointer to a small
754 * on-stack array in @fast_pointer, typically %UIO_FASTIOV elements long
755 * (the size of this array, or 0 if unused, should be given in @fast_segs).
757 * @ret_pointer will always point to the array that was used, so the
758 * caller must take care not to call kfree() on it e.g. in case the
759 * @fast_pointer array was used and it was allocated on the stack.
761 * Return: The total number of bytes covered by the iovec array on success
762 * or a negative error code on error.
764 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
765 unsigned long nr_segs, unsigned long fast_segs,
766 struct iovec *fast_pointer,
767 struct iovec **ret_pointer)
771 struct iovec *iov = fast_pointer;
774 * SuS says "The readv() function *may* fail if the iovcnt argument
775 * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
776 * traditionally returned zero for zero segments, so...
784 * First get the "struct iovec" from user memory and
785 * verify all the pointers
787 if (nr_segs > UIO_MAXIOV) {
791 if (nr_segs > fast_segs) {
792 iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
798 if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
804 * According to the Single Unix Specification we should return EINVAL
805 * if an element length is < 0 when cast to ssize_t or if the
806 * total length would overflow the ssize_t return value of the
809 * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
813 for (seg = 0; seg < nr_segs; seg++) {
814 void __user *buf = iov[seg].iov_base;
815 ssize_t len = (ssize_t)iov[seg].iov_len;
817 /* see if we we're about to use an invalid len or if
818 * it's about to overflow ssize_t */
824 && unlikely(!access_ok(vrfy_dir(type), buf, len))) {
828 if (len > MAX_RW_COUNT - ret) {
829 len = MAX_RW_COUNT - ret;
830 iov[seg].iov_len = len;
839 static ssize_t do_readv_writev(int type, struct file *file,
840 const struct iovec __user * uvector,
841 unsigned long nr_segs, loff_t *pos,
845 struct iovec iovstack[UIO_FASTIOV];
846 struct iovec *iov = iovstack;
847 struct iov_iter iter;
852 ret = import_iovec(type, uvector, nr_segs,
853 ARRAY_SIZE(iovstack), &iov, &iter);
857 tot_len = iov_iter_count(&iter);
860 ret = rw_verify_area(type, file, pos, tot_len);
865 fn = file->f_op->read;
866 iter_fn = file->f_op->read_iter;
868 fn = (io_fn_t)file->f_op->write;
869 iter_fn = file->f_op->write_iter;
870 file_start_write(file);
874 ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
876 ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
879 file_end_write(file);
883 if ((ret + (type == READ)) > 0) {
885 fsnotify_access(file);
887 fsnotify_modify(file);
892 ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
893 unsigned long vlen, loff_t *pos, int flags)
895 if (!(file->f_mode & FMODE_READ))
897 if (!(file->f_mode & FMODE_CAN_READ))
900 return do_readv_writev(READ, file, vec, vlen, pos, flags);
903 EXPORT_SYMBOL(vfs_readv);
905 ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
906 unsigned long vlen, loff_t *pos, int flags)
908 if (!(file->f_mode & FMODE_WRITE))
910 if (!(file->f_mode & FMODE_CAN_WRITE))
913 return do_readv_writev(WRITE, file, vec, vlen, pos, flags);
916 EXPORT_SYMBOL(vfs_writev);
918 static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
919 unsigned long vlen, int flags)
921 struct fd f = fdget_pos(fd);
922 ssize_t ret = -EBADF;
925 loff_t pos = file_pos_read(f.file);
926 ret = vfs_readv(f.file, vec, vlen, &pos, flags);
928 file_pos_write(f.file, pos);
933 add_rchar(current, ret);
938 static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec,
939 unsigned long vlen, int flags)
941 struct fd f = fdget_pos(fd);
942 ssize_t ret = -EBADF;
945 loff_t pos = file_pos_read(f.file);
946 ret = vfs_writev(f.file, vec, vlen, &pos, flags);
948 file_pos_write(f.file, pos);
953 add_wchar(current, ret);
958 static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
960 #define HALF_LONG_BITS (BITS_PER_LONG / 2)
961 return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
964 static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec,
965 unsigned long vlen, loff_t pos, int flags)
968 ssize_t ret = -EBADF;
976 if (f.file->f_mode & FMODE_PREAD)
977 ret = vfs_readv(f.file, vec, vlen, &pos, flags);
982 add_rchar(current, ret);
987 static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec,
988 unsigned long vlen, loff_t pos, int flags)
991 ssize_t ret = -EBADF;
999 if (f.file->f_mode & FMODE_PWRITE)
1000 ret = vfs_writev(f.file, vec, vlen, &pos, flags);
1005 add_wchar(current, ret);
1010 SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
1011 unsigned long, vlen)
1013 return do_readv(fd, vec, vlen, 0);
1016 SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
1017 unsigned long, vlen)
1019 return do_writev(fd, vec, vlen, 0);
1022 SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
1023 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
1025 loff_t pos = pos_from_hilo(pos_h, pos_l);
1027 return do_preadv(fd, vec, vlen, pos, 0);
1030 SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec,
1031 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
1034 loff_t pos = pos_from_hilo(pos_h, pos_l);
1037 return do_readv(fd, vec, vlen, flags);
1039 return do_preadv(fd, vec, vlen, pos, flags);
1042 SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
1043 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
1045 loff_t pos = pos_from_hilo(pos_h, pos_l);
1047 return do_pwritev(fd, vec, vlen, pos, 0);
1050 SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
1051 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
1054 loff_t pos = pos_from_hilo(pos_h, pos_l);
1057 return do_writev(fd, vec, vlen, flags);
1059 return do_pwritev(fd, vec, vlen, pos, flags);
1062 #ifdef CONFIG_COMPAT
1064 static ssize_t compat_do_readv_writev(int type, struct file *file,
1065 const struct compat_iovec __user *uvector,
1066 unsigned long nr_segs, loff_t *pos,
1069 compat_ssize_t tot_len;
1070 struct iovec iovstack[UIO_FASTIOV];
1071 struct iovec *iov = iovstack;
1072 struct iov_iter iter;
1077 ret = compat_import_iovec(type, uvector, nr_segs,
1078 UIO_FASTIOV, &iov, &iter);
1082 tot_len = iov_iter_count(&iter);
1085 ret = rw_verify_area(type, file, pos, tot_len);
1090 fn = file->f_op->read;
1091 iter_fn = file->f_op->read_iter;
1093 fn = (io_fn_t)file->f_op->write;
1094 iter_fn = file->f_op->write_iter;
1095 file_start_write(file);
1099 ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
1101 ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
1104 file_end_write(file);
1108 if ((ret + (type == READ)) > 0) {
1110 fsnotify_access(file);
1112 fsnotify_modify(file);
1117 static size_t compat_readv(struct file *file,
1118 const struct compat_iovec __user *vec,
1119 unsigned long vlen, loff_t *pos, int flags)
1121 ssize_t ret = -EBADF;
1123 if (!(file->f_mode & FMODE_READ))
1127 if (!(file->f_mode & FMODE_CAN_READ))
1130 ret = compat_do_readv_writev(READ, file, vec, vlen, pos, flags);
1134 add_rchar(current, ret);
1139 static size_t do_compat_readv(compat_ulong_t fd,
1140 const struct compat_iovec __user *vec,
1141 compat_ulong_t vlen, int flags)
1143 struct fd f = fdget_pos(fd);
1149 pos = f.file->f_pos;
1150 ret = compat_readv(f.file, vec, vlen, &pos, flags);
1152 f.file->f_pos = pos;
1158 COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
1159 const struct compat_iovec __user *,vec,
1160 compat_ulong_t, vlen)
1162 return do_compat_readv(fd, vec, vlen, 0);
1165 static long do_compat_preadv64(unsigned long fd,
1166 const struct compat_iovec __user *vec,
1167 unsigned long vlen, loff_t pos, int flags)
1178 if (f.file->f_mode & FMODE_PREAD)
1179 ret = compat_readv(f.file, vec, vlen, &pos, flags);
1184 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
1185 COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
1186 const struct compat_iovec __user *,vec,
1187 unsigned long, vlen, loff_t, pos)
1189 return do_compat_preadv64(fd, vec, vlen, pos, 0);
1193 COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
1194 const struct compat_iovec __user *,vec,
1195 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1197 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1199 return do_compat_preadv64(fd, vec, vlen, pos, 0);
1202 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
1203 COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
1204 const struct compat_iovec __user *,vec,
1205 unsigned long, vlen, loff_t, pos, int, flags)
1208 return do_compat_readv(fd, vec, vlen, flags);
1210 return do_compat_preadv64(fd, vec, vlen, pos, flags);
1214 COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
1215 const struct compat_iovec __user *,vec,
1216 compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
1219 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1222 return do_compat_readv(fd, vec, vlen, flags);
1224 return do_compat_preadv64(fd, vec, vlen, pos, flags);
1227 static size_t compat_writev(struct file *file,
1228 const struct compat_iovec __user *vec,
1229 unsigned long vlen, loff_t *pos, int flags)
1231 ssize_t ret = -EBADF;
1233 if (!(file->f_mode & FMODE_WRITE))
1237 if (!(file->f_mode & FMODE_CAN_WRITE))
1240 ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos, flags);
1244 add_wchar(current, ret);
1249 static size_t do_compat_writev(compat_ulong_t fd,
1250 const struct compat_iovec __user* vec,
1251 compat_ulong_t vlen, int flags)
1253 struct fd f = fdget_pos(fd);
1259 pos = f.file->f_pos;
1260 ret = compat_writev(f.file, vec, vlen, &pos, flags);
1262 f.file->f_pos = pos;
1267 COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
1268 const struct compat_iovec __user *, vec,
1269 compat_ulong_t, vlen)
1271 return do_compat_writev(fd, vec, vlen, 0);
1274 static long do_compat_pwritev64(unsigned long fd,
1275 const struct compat_iovec __user *vec,
1276 unsigned long vlen, loff_t pos, int flags)
1287 if (f.file->f_mode & FMODE_PWRITE)
1288 ret = compat_writev(f.file, vec, vlen, &pos, flags);
1293 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
1294 COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
1295 const struct compat_iovec __user *,vec,
1296 unsigned long, vlen, loff_t, pos)
1298 return do_compat_pwritev64(fd, vec, vlen, pos, 0);
1302 COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
1303 const struct compat_iovec __user *,vec,
1304 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1306 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1308 return do_compat_pwritev64(fd, vec, vlen, pos, 0);
1311 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
1312 COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
1313 const struct compat_iovec __user *,vec,
1314 unsigned long, vlen, loff_t, pos, int, flags)
1317 return do_compat_writev(fd, vec, vlen, flags);
1319 return do_compat_pwritev64(fd, vec, vlen, pos, flags);
1323 COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
1324 const struct compat_iovec __user *,vec,
1325 compat_ulong_t, vlen, u32, pos_low, u32, pos_high, int, flags)
1327 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1330 return do_compat_writev(fd, vec, vlen, flags);
1332 return do_compat_pwritev64(fd, vec, vlen, pos, flags);
1337 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
1338 size_t count, loff_t max)
1341 struct inode *in_inode, *out_inode;
1348 * Get input file, and verify that it is ok..
1354 if (!(in.file->f_mode & FMODE_READ))
1358 pos = in.file->f_pos;
1361 if (!(in.file->f_mode & FMODE_PREAD))
1364 retval = rw_verify_area(READ, in.file, &pos, count);
1367 if (count > MAX_RW_COUNT)
1368 count = MAX_RW_COUNT;
1371 * Get output file, and verify that it is ok..
1374 out = fdget(out_fd);
1377 if (!(out.file->f_mode & FMODE_WRITE))
1380 in_inode = file_inode(in.file);
1381 out_inode = file_inode(out.file);
1382 out_pos = out.file->f_pos;
1383 retval = rw_verify_area(WRITE, out.file, &out_pos, count);
1388 max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
1390 if (unlikely(pos + count > max)) {
1391 retval = -EOVERFLOW;
1400 * We need to debate whether we can enable this or not. The
1401 * man page documents EAGAIN return for the output at least,
1402 * and the application is arguably buggy if it doesn't expect
1403 * EAGAIN on a non-blocking file descriptor.
1405 if (in.file->f_flags & O_NONBLOCK)
1406 fl = SPLICE_F_NONBLOCK;
1408 file_start_write(out.file);
1409 retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
1410 file_end_write(out.file);
1413 add_rchar(current, retval);
1414 add_wchar(current, retval);
1415 fsnotify_access(in.file);
1416 fsnotify_modify(out.file);
1417 out.file->f_pos = out_pos;
1421 in.file->f_pos = pos;
1427 retval = -EOVERFLOW;
1437 SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
1444 if (unlikely(get_user(off, offset)))
1447 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1448 if (unlikely(put_user(pos, offset)))
1453 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1456 SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
1462 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1464 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1465 if (unlikely(put_user(pos, offset)))
1470 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1473 #ifdef CONFIG_COMPAT
1474 COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
1475 compat_off_t __user *, offset, compat_size_t, count)
1482 if (unlikely(get_user(off, offset)))
1485 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1486 if (unlikely(put_user(pos, offset)))
1491 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1494 COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
1495 compat_loff_t __user *, offset, compat_size_t, count)
1501 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1503 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1504 if (unlikely(put_user(pos, offset)))
1509 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1514 * copy_file_range() differs from regular file read and write in that it
1515 * specifically allows return partial success. When it does so is up to
1516 * the copy_file_range method.
1518 ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
1519 struct file *file_out, loff_t pos_out,
1520 size_t len, unsigned int flags)
1522 struct inode *inode_in = file_inode(file_in);
1523 struct inode *inode_out = file_inode(file_out);
1529 if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
1531 if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
1534 ret = rw_verify_area(READ, file_in, &pos_in, len);
1538 ret = rw_verify_area(WRITE, file_out, &pos_out, len);
1542 if (!(file_in->f_mode & FMODE_READ) ||
1543 !(file_out->f_mode & FMODE_WRITE) ||
1544 (file_out->f_flags & O_APPEND))
1547 /* this could be relaxed once a method supports cross-fs copies */
1548 if (inode_in->i_sb != inode_out->i_sb)
1554 ret = mnt_want_write_file(file_out);
1559 if (file_out->f_op->copy_file_range)
1560 ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
1561 pos_out, len, flags);
1562 if (ret == -EOPNOTSUPP)
1563 ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
1564 len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
1567 fsnotify_access(file_in);
1568 add_rchar(current, ret);
1569 fsnotify_modify(file_out);
1570 add_wchar(current, ret);
1575 mnt_drop_write_file(file_out);
1579 EXPORT_SYMBOL(vfs_copy_file_range);
1581 SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in,
1582 int, fd_out, loff_t __user *, off_out,
1583 size_t, len, unsigned int, flags)
1589 ssize_t ret = -EBADF;
1591 f_in = fdget(fd_in);
1595 f_out = fdget(fd_out);
1601 if (copy_from_user(&pos_in, off_in, sizeof(loff_t)))
1604 pos_in = f_in.file->f_pos;
1608 if (copy_from_user(&pos_out, off_out, sizeof(loff_t)))
1611 pos_out = f_out.file->f_pos;
1614 ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len,
1621 if (copy_to_user(off_in, &pos_in, sizeof(loff_t)))
1624 f_in.file->f_pos = pos_in;
1628 if (copy_to_user(off_out, &pos_out, sizeof(loff_t)))
1631 f_out.file->f_pos = pos_out;
1643 static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write)
1645 struct inode *inode = file_inode(file);
1647 if (unlikely(pos < 0))
1650 if (unlikely((loff_t) (pos + len) < 0))
1653 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
1654 loff_t end = len ? pos + len - 1 : OFFSET_MAX;
1657 retval = locks_mandatory_area(inode, file, pos, end,
1658 write ? F_WRLCK : F_RDLCK);
1663 return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
1666 int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
1667 struct file *file_out, loff_t pos_out, u64 len)
1669 struct inode *inode_in = file_inode(file_in);
1670 struct inode *inode_out = file_inode(file_out);
1673 if (inode_in->i_sb != inode_out->i_sb ||
1674 file_in->f_path.mnt != file_out->f_path.mnt)
1677 if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
1679 if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
1682 if (!(file_in->f_mode & FMODE_READ) ||
1683 !(file_out->f_mode & FMODE_WRITE) ||
1684 (file_out->f_flags & O_APPEND))
1687 if (!file_in->f_op->clone_file_range)
1690 ret = clone_verify_area(file_in, pos_in, len, false);
1694 ret = clone_verify_area(file_out, pos_out, len, true);
1698 if (pos_in + len > i_size_read(inode_in))
1701 ret = mnt_want_write_file(file_out);
1705 ret = file_in->f_op->clone_file_range(file_in, pos_in,
1706 file_out, pos_out, len);
1708 fsnotify_access(file_in);
1709 fsnotify_modify(file_out);
1712 mnt_drop_write_file(file_out);
1715 EXPORT_SYMBOL(vfs_clone_file_range);
1717 int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
1719 struct file_dedupe_range_info *info;
1720 struct inode *src = file_inode(file);
1725 bool is_admin = capable(CAP_SYS_ADMIN);
1726 u16 count = same->dest_count;
1727 struct file *dst_file;
1731 if (!(file->f_mode & FMODE_READ))
1734 if (same->reserved1 || same->reserved2)
1737 off = same->src_offset;
1738 len = same->src_length;
1741 if (S_ISDIR(src->i_mode))
1745 if (!S_ISREG(src->i_mode))
1748 ret = clone_verify_area(file, off, len, false);
1753 /* pre-format output fields to sane values */
1754 for (i = 0; i < count; i++) {
1755 same->info[i].bytes_deduped = 0ULL;
1756 same->info[i].status = FILE_DEDUPE_RANGE_SAME;
1759 for (i = 0, info = same->info; i < count; i++, info++) {
1761 struct fd dst_fd = fdget(info->dest_fd);
1763 dst_file = dst_fd.file;
1765 info->status = -EBADF;
1768 dst = file_inode(dst_file);
1770 ret = mnt_want_write_file(dst_file);
1776 dst_off = info->dest_offset;
1777 ret = clone_verify_area(dst_file, dst_off, len, true);
1784 if (info->reserved) {
1785 info->status = -EINVAL;
1786 } else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) {
1787 info->status = -EINVAL;
1788 } else if (file->f_path.mnt != dst_file->f_path.mnt) {
1789 info->status = -EXDEV;
1790 } else if (S_ISDIR(dst->i_mode)) {
1791 info->status = -EISDIR;
1792 } else if (dst_file->f_op->dedupe_file_range == NULL) {
1793 info->status = -EINVAL;
1795 deduped = dst_file->f_op->dedupe_file_range(file, off,
1798 if (deduped == -EBADE)
1799 info->status = FILE_DEDUPE_RANGE_DIFFERS;
1800 else if (deduped < 0)
1801 info->status = deduped;
1803 info->bytes_deduped += deduped;
1807 mnt_drop_write_file(dst_file);
1811 if (fatal_signal_pending(current))
1818 EXPORT_SYMBOL(vfs_dedupe_file_range);