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.
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.
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;
399 EXPORT_SYMBOL(vfs_iter_write);
402 * rw_verify_area doesn't like huge counts. We limit
403 * them to something that fits in "int" so that others
404 * won't have to do range checks all the time.
406 int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
410 int retval = -EINVAL;
412 inode = file_inode(file);
413 if (unlikely((ssize_t) count < 0))
416 if (unlikely(pos < 0)) {
417 if (!unsigned_offsets(file))
419 if (count >= -pos) /* both values are in 0..LLONG_MAX */
421 } else if (unlikely((loff_t) (pos + count) < 0)) {
422 if (!unsigned_offsets(file))
426 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
427 retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
428 read_write == READ ? F_RDLCK : F_WRLCK);
432 retval = security_file_permission(file,
433 read_write == READ ? MAY_READ : MAY_WRITE);
436 return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
439 static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
441 struct iovec iov = { .iov_base = buf, .iov_len = len };
443 struct iov_iter iter;
446 init_sync_kiocb(&kiocb, filp);
447 kiocb.ki_pos = *ppos;
448 iov_iter_init(&iter, READ, &iov, 1, len);
450 ret = filp->f_op->read_iter(&kiocb, &iter);
451 BUG_ON(ret == -EIOCBQUEUED);
452 *ppos = kiocb.ki_pos;
456 ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
459 if (file->f_op->read)
460 return file->f_op->read(file, buf, count, pos);
461 else if (file->f_op->read_iter)
462 return new_sync_read(file, buf, count, pos);
466 EXPORT_SYMBOL(__vfs_read);
468 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
472 if (!(file->f_mode & FMODE_READ))
474 if (!(file->f_mode & FMODE_CAN_READ))
476 if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
479 ret = rw_verify_area(READ, file, pos, count);
482 ret = __vfs_read(file, buf, count, pos);
484 fsnotify_access(file);
485 add_rchar(current, ret);
493 EXPORT_SYMBOL(vfs_read);
495 static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
497 struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
499 struct iov_iter iter;
502 init_sync_kiocb(&kiocb, filp);
503 kiocb.ki_pos = *ppos;
504 iov_iter_init(&iter, WRITE, &iov, 1, len);
506 ret = filp->f_op->write_iter(&kiocb, &iter);
507 BUG_ON(ret == -EIOCBQUEUED);
509 *ppos = kiocb.ki_pos;
513 ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
516 if (file->f_op->write)
517 return file->f_op->write(file, p, count, pos);
518 else if (file->f_op->write_iter)
519 return new_sync_write(file, p, count, pos);
523 EXPORT_SYMBOL(__vfs_write);
525 ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
528 const char __user *p;
531 if (!(file->f_mode & FMODE_CAN_WRITE))
536 p = (__force const char __user *)buf;
537 if (count > MAX_RW_COUNT)
538 count = MAX_RW_COUNT;
539 ret = __vfs_write(file, p, count, pos);
542 fsnotify_modify(file);
543 add_wchar(current, ret);
549 EXPORT_SYMBOL(__kernel_write);
551 ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
555 if (!(file->f_mode & FMODE_WRITE))
557 if (!(file->f_mode & FMODE_CAN_WRITE))
559 if (unlikely(!access_ok(VERIFY_READ, buf, count)))
562 ret = rw_verify_area(WRITE, file, pos, count);
565 file_start_write(file);
566 ret = __vfs_write(file, buf, count, pos);
568 fsnotify_modify(file);
569 add_wchar(current, ret);
572 file_end_write(file);
578 EXPORT_SYMBOL(vfs_write);
580 static inline loff_t file_pos_read(struct file *file)
585 static inline void file_pos_write(struct file *file, loff_t pos)
590 SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
592 struct fd f = fdget_pos(fd);
593 ssize_t ret = -EBADF;
596 loff_t pos = file_pos_read(f.file);
597 ret = vfs_read(f.file, buf, count, &pos);
599 file_pos_write(f.file, pos);
605 SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
608 struct fd f = fdget_pos(fd);
609 ssize_t ret = -EBADF;
612 loff_t pos = file_pos_read(f.file);
613 ret = vfs_write(f.file, buf, count, &pos);
615 file_pos_write(f.file, pos);
622 SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
623 size_t, count, loff_t, pos)
626 ssize_t ret = -EBADF;
634 if (f.file->f_mode & FMODE_PREAD)
635 ret = vfs_read(f.file, buf, count, &pos);
642 SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
643 size_t, count, loff_t, pos)
646 ssize_t ret = -EBADF;
654 if (f.file->f_mode & FMODE_PWRITE)
655 ret = vfs_write(f.file, buf, count, &pos);
663 * Reduce an iovec's length in-place. Return the resulting number of segments
665 unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
667 unsigned long seg = 0;
670 while (seg < nr_segs) {
672 if (len + iov->iov_len >= to) {
673 iov->iov_len = to - len;
681 EXPORT_SYMBOL(iov_shorten);
683 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
684 loff_t *ppos, iter_fn_t fn, int flags)
689 if (flags & ~RWF_HIPRI)
692 init_sync_kiocb(&kiocb, filp);
693 if (flags & RWF_HIPRI)
694 kiocb.ki_flags |= IOCB_HIPRI;
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)
735 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
736 unsigned long nr_segs, unsigned long fast_segs,
737 struct iovec *fast_pointer,
738 struct iovec **ret_pointer)
742 struct iovec *iov = fast_pointer;
745 * SuS says "The readv() function *may* fail if the iovcnt argument
746 * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
747 * traditionally returned zero for zero segments, so...
755 * First get the "struct iovec" from user memory and
756 * verify all the pointers
758 if (nr_segs > UIO_MAXIOV) {
762 if (nr_segs > fast_segs) {
763 iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
769 if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
775 * According to the Single Unix Specification we should return EINVAL
776 * if an element length is < 0 when cast to ssize_t or if the
777 * total length would overflow the ssize_t return value of the
780 * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
784 for (seg = 0; seg < nr_segs; seg++) {
785 void __user *buf = iov[seg].iov_base;
786 ssize_t len = (ssize_t)iov[seg].iov_len;
788 /* see if we we're about to use an invalid len or if
789 * it's about to overflow ssize_t */
795 && unlikely(!access_ok(vrfy_dir(type), buf, len))) {
799 if (len > MAX_RW_COUNT - ret) {
800 len = MAX_RW_COUNT - ret;
801 iov[seg].iov_len = len;
810 static ssize_t do_readv_writev(int type, struct file *file,
811 const struct iovec __user * uvector,
812 unsigned long nr_segs, loff_t *pos,
816 struct iovec iovstack[UIO_FASTIOV];
817 struct iovec *iov = iovstack;
818 struct iov_iter iter;
823 ret = import_iovec(type, uvector, nr_segs,
824 ARRAY_SIZE(iovstack), &iov, &iter);
828 tot_len = iov_iter_count(&iter);
831 ret = rw_verify_area(type, file, pos, tot_len);
836 fn = file->f_op->read;
837 iter_fn = file->f_op->read_iter;
839 fn = (io_fn_t)file->f_op->write;
840 iter_fn = file->f_op->write_iter;
841 file_start_write(file);
845 ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
847 ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
850 file_end_write(file);
854 if ((ret + (type == READ)) > 0) {
856 fsnotify_access(file);
858 fsnotify_modify(file);
863 ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
864 unsigned long vlen, loff_t *pos, int flags)
866 if (!(file->f_mode & FMODE_READ))
868 if (!(file->f_mode & FMODE_CAN_READ))
871 return do_readv_writev(READ, file, vec, vlen, pos, flags);
874 EXPORT_SYMBOL(vfs_readv);
876 ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
877 unsigned long vlen, loff_t *pos, int flags)
879 if (!(file->f_mode & FMODE_WRITE))
881 if (!(file->f_mode & FMODE_CAN_WRITE))
884 return do_readv_writev(WRITE, file, vec, vlen, pos, flags);
887 EXPORT_SYMBOL(vfs_writev);
889 static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
890 unsigned long vlen, int flags)
892 struct fd f = fdget_pos(fd);
893 ssize_t ret = -EBADF;
896 loff_t pos = file_pos_read(f.file);
897 ret = vfs_readv(f.file, vec, vlen, &pos, flags);
899 file_pos_write(f.file, pos);
904 add_rchar(current, ret);
909 static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec,
910 unsigned long vlen, int flags)
912 struct fd f = fdget_pos(fd);
913 ssize_t ret = -EBADF;
916 loff_t pos = file_pos_read(f.file);
917 ret = vfs_writev(f.file, vec, vlen, &pos, flags);
919 file_pos_write(f.file, pos);
924 add_wchar(current, ret);
929 static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
931 #define HALF_LONG_BITS (BITS_PER_LONG / 2)
932 return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
935 static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec,
936 unsigned long vlen, loff_t pos, int flags)
939 ssize_t ret = -EBADF;
947 if (f.file->f_mode & FMODE_PREAD)
948 ret = vfs_readv(f.file, vec, vlen, &pos, flags);
953 add_rchar(current, ret);
958 static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec,
959 unsigned long vlen, loff_t pos, int flags)
962 ssize_t ret = -EBADF;
970 if (f.file->f_mode & FMODE_PWRITE)
971 ret = vfs_writev(f.file, vec, vlen, &pos, flags);
976 add_wchar(current, ret);
981 SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
984 return do_readv(fd, vec, vlen, 0);
987 SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
990 return do_writev(fd, vec, vlen, 0);
993 SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
994 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
996 loff_t pos = pos_from_hilo(pos_h, pos_l);
998 return do_preadv(fd, vec, vlen, pos, 0);
1001 SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec,
1002 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
1005 loff_t pos = pos_from_hilo(pos_h, pos_l);
1008 return do_readv(fd, vec, vlen, flags);
1010 return do_preadv(fd, vec, vlen, pos, flags);
1013 SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
1014 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
1016 loff_t pos = pos_from_hilo(pos_h, pos_l);
1018 return do_pwritev(fd, vec, vlen, pos, 0);
1021 SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
1022 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
1025 loff_t pos = pos_from_hilo(pos_h, pos_l);
1028 return do_writev(fd, vec, vlen, flags);
1030 return do_pwritev(fd, vec, vlen, pos, flags);
1033 #ifdef CONFIG_COMPAT
1035 static ssize_t compat_do_readv_writev(int type, struct file *file,
1036 const struct compat_iovec __user *uvector,
1037 unsigned long nr_segs, loff_t *pos,
1040 compat_ssize_t tot_len;
1041 struct iovec iovstack[UIO_FASTIOV];
1042 struct iovec *iov = iovstack;
1043 struct iov_iter iter;
1048 ret = compat_import_iovec(type, uvector, nr_segs,
1049 UIO_FASTIOV, &iov, &iter);
1053 tot_len = iov_iter_count(&iter);
1056 ret = rw_verify_area(type, file, pos, tot_len);
1061 fn = file->f_op->read;
1062 iter_fn = file->f_op->read_iter;
1064 fn = (io_fn_t)file->f_op->write;
1065 iter_fn = file->f_op->write_iter;
1066 file_start_write(file);
1070 ret = do_iter_readv_writev(file, &iter, pos, iter_fn, flags);
1072 ret = do_loop_readv_writev(file, &iter, pos, fn, flags);
1075 file_end_write(file);
1079 if ((ret + (type == READ)) > 0) {
1081 fsnotify_access(file);
1083 fsnotify_modify(file);
1088 static size_t compat_readv(struct file *file,
1089 const struct compat_iovec __user *vec,
1090 unsigned long vlen, loff_t *pos, int flags)
1092 ssize_t ret = -EBADF;
1094 if (!(file->f_mode & FMODE_READ))
1098 if (!(file->f_mode & FMODE_CAN_READ))
1101 ret = compat_do_readv_writev(READ, file, vec, vlen, pos, flags);
1105 add_rchar(current, ret);
1110 static size_t do_compat_readv(compat_ulong_t fd,
1111 const struct compat_iovec __user *vec,
1112 compat_ulong_t vlen, int flags)
1114 struct fd f = fdget_pos(fd);
1120 pos = f.file->f_pos;
1121 ret = compat_readv(f.file, vec, vlen, &pos, flags);
1123 f.file->f_pos = pos;
1129 COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
1130 const struct compat_iovec __user *,vec,
1131 compat_ulong_t, vlen)
1133 return do_compat_readv(fd, vec, vlen, 0);
1136 static long do_compat_preadv64(unsigned long fd,
1137 const struct compat_iovec __user *vec,
1138 unsigned long vlen, loff_t pos, int flags)
1149 if (f.file->f_mode & FMODE_PREAD)
1150 ret = compat_readv(f.file, vec, vlen, &pos, flags);
1155 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
1156 COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
1157 const struct compat_iovec __user *,vec,
1158 unsigned long, vlen, loff_t, pos)
1160 return do_compat_preadv64(fd, vec, vlen, pos, 0);
1164 COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
1165 const struct compat_iovec __user *,vec,
1166 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1168 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1170 return do_compat_preadv64(fd, vec, vlen, pos, 0);
1173 COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
1174 const struct compat_iovec __user *,vec,
1175 compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
1178 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1181 return do_compat_readv(fd, vec, vlen, flags);
1183 return do_compat_preadv64(fd, vec, vlen, pos, flags);
1186 static size_t compat_writev(struct file *file,
1187 const struct compat_iovec __user *vec,
1188 unsigned long vlen, loff_t *pos, int flags)
1190 ssize_t ret = -EBADF;
1192 if (!(file->f_mode & FMODE_WRITE))
1196 if (!(file->f_mode & FMODE_CAN_WRITE))
1199 ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos, 0);
1203 add_wchar(current, ret);
1208 static size_t do_compat_writev(compat_ulong_t fd,
1209 const struct compat_iovec __user* vec,
1210 compat_ulong_t vlen, int flags)
1212 struct fd f = fdget_pos(fd);
1218 pos = f.file->f_pos;
1219 ret = compat_writev(f.file, vec, vlen, &pos, flags);
1221 f.file->f_pos = pos;
1226 COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
1227 const struct compat_iovec __user *, vec,
1228 compat_ulong_t, vlen)
1230 return do_compat_writev(fd, vec, vlen, 0);
1233 static long do_compat_pwritev64(unsigned long fd,
1234 const struct compat_iovec __user *vec,
1235 unsigned long vlen, loff_t pos, int flags)
1246 if (f.file->f_mode & FMODE_PWRITE)
1247 ret = compat_writev(f.file, vec, vlen, &pos, flags);
1252 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
1253 COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
1254 const struct compat_iovec __user *,vec,
1255 unsigned long, vlen, loff_t, pos)
1257 return do_compat_pwritev64(fd, vec, vlen, pos, 0);
1261 COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
1262 const struct compat_iovec __user *,vec,
1263 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1265 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1267 return do_compat_pwritev64(fd, vec, vlen, pos, 0);
1270 COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
1271 const struct compat_iovec __user *,vec,
1272 compat_ulong_t, vlen, u32, pos_low, u32, pos_high, int, flags)
1274 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1277 return do_compat_writev(fd, vec, vlen, flags);
1279 return do_compat_pwritev64(fd, vec, vlen, pos, flags);
1284 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
1285 size_t count, loff_t max)
1288 struct inode *in_inode, *out_inode;
1295 * Get input file, and verify that it is ok..
1301 if (!(in.file->f_mode & FMODE_READ))
1305 pos = in.file->f_pos;
1308 if (!(in.file->f_mode & FMODE_PREAD))
1311 retval = rw_verify_area(READ, in.file, &pos, count);
1317 * Get output file, and verify that it is ok..
1320 out = fdget(out_fd);
1323 if (!(out.file->f_mode & FMODE_WRITE))
1326 in_inode = file_inode(in.file);
1327 out_inode = file_inode(out.file);
1328 out_pos = out.file->f_pos;
1329 retval = rw_verify_area(WRITE, out.file, &out_pos, count);
1335 max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
1337 if (unlikely(pos + count > max)) {
1338 retval = -EOVERFLOW;
1347 * We need to debate whether we can enable this or not. The
1348 * man page documents EAGAIN return for the output at least,
1349 * and the application is arguably buggy if it doesn't expect
1350 * EAGAIN on a non-blocking file descriptor.
1352 if (in.file->f_flags & O_NONBLOCK)
1353 fl = SPLICE_F_NONBLOCK;
1355 file_start_write(out.file);
1356 retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
1357 file_end_write(out.file);
1360 add_rchar(current, retval);
1361 add_wchar(current, retval);
1362 fsnotify_access(in.file);
1363 fsnotify_modify(out.file);
1364 out.file->f_pos = out_pos;
1368 in.file->f_pos = pos;
1374 retval = -EOVERFLOW;
1384 SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
1391 if (unlikely(get_user(off, offset)))
1394 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1395 if (unlikely(put_user(pos, offset)))
1400 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1403 SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
1409 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1411 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1412 if (unlikely(put_user(pos, offset)))
1417 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1420 #ifdef CONFIG_COMPAT
1421 COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
1422 compat_off_t __user *, offset, compat_size_t, count)
1429 if (unlikely(get_user(off, offset)))
1432 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1433 if (unlikely(put_user(pos, offset)))
1438 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1441 COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
1442 compat_loff_t __user *, offset, compat_size_t, count)
1448 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1450 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1451 if (unlikely(put_user(pos, offset)))
1456 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1461 * copy_file_range() differs from regular file read and write in that it
1462 * specifically allows return partial success. When it does so is up to
1463 * the copy_file_range method.
1465 ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
1466 struct file *file_out, loff_t pos_out,
1467 size_t len, unsigned int flags)
1469 struct inode *inode_in = file_inode(file_in);
1470 struct inode *inode_out = file_inode(file_out);
1476 /* copy_file_range allows full ssize_t len, ignoring MAX_RW_COUNT */
1477 ret = rw_verify_area(READ, file_in, &pos_in, len);
1479 ret = rw_verify_area(WRITE, file_out, &pos_out, len);
1483 if (!(file_in->f_mode & FMODE_READ) ||
1484 !(file_out->f_mode & FMODE_WRITE) ||
1485 (file_out->f_flags & O_APPEND))
1488 /* this could be relaxed once a method supports cross-fs copies */
1489 if (inode_in->i_sb != inode_out->i_sb)
1495 ret = mnt_want_write_file(file_out);
1500 if (file_out->f_op->copy_file_range)
1501 ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
1502 pos_out, len, flags);
1503 if (ret == -EOPNOTSUPP)
1504 ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
1505 len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
1508 fsnotify_access(file_in);
1509 add_rchar(current, ret);
1510 fsnotify_modify(file_out);
1511 add_wchar(current, ret);
1516 mnt_drop_write_file(file_out);
1520 EXPORT_SYMBOL(vfs_copy_file_range);
1522 SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in,
1523 int, fd_out, loff_t __user *, off_out,
1524 size_t, len, unsigned int, flags)
1530 ssize_t ret = -EBADF;
1532 f_in = fdget(fd_in);
1536 f_out = fdget(fd_out);
1542 if (copy_from_user(&pos_in, off_in, sizeof(loff_t)))
1545 pos_in = f_in.file->f_pos;
1549 if (copy_from_user(&pos_out, off_out, sizeof(loff_t)))
1552 pos_out = f_out.file->f_pos;
1555 ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len,
1562 if (copy_to_user(off_in, &pos_in, sizeof(loff_t)))
1565 f_in.file->f_pos = pos_in;
1569 if (copy_to_user(off_out, &pos_out, sizeof(loff_t)))
1572 f_out.file->f_pos = pos_out;
1584 static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write)
1586 struct inode *inode = file_inode(file);
1588 if (unlikely(pos < 0))
1591 if (unlikely((loff_t) (pos + len) < 0))
1594 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
1595 loff_t end = len ? pos + len - 1 : OFFSET_MAX;
1598 retval = locks_mandatory_area(inode, file, pos, end,
1599 write ? F_WRLCK : F_RDLCK);
1604 return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
1607 int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
1608 struct file *file_out, loff_t pos_out, u64 len)
1610 struct inode *inode_in = file_inode(file_in);
1611 struct inode *inode_out = file_inode(file_out);
1614 if (inode_in->i_sb != inode_out->i_sb ||
1615 file_in->f_path.mnt != file_out->f_path.mnt)
1618 if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
1620 if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
1623 if (!(file_in->f_mode & FMODE_READ) ||
1624 !(file_out->f_mode & FMODE_WRITE) ||
1625 (file_out->f_flags & O_APPEND))
1628 if (!file_in->f_op->clone_file_range)
1631 ret = clone_verify_area(file_in, pos_in, len, false);
1635 ret = clone_verify_area(file_out, pos_out, len, true);
1639 if (pos_in + len > i_size_read(inode_in))
1642 ret = mnt_want_write_file(file_out);
1646 ret = file_in->f_op->clone_file_range(file_in, pos_in,
1647 file_out, pos_out, len);
1649 fsnotify_access(file_in);
1650 fsnotify_modify(file_out);
1653 mnt_drop_write_file(file_out);
1656 EXPORT_SYMBOL(vfs_clone_file_range);
1658 int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
1660 struct file_dedupe_range_info *info;
1661 struct inode *src = file_inode(file);
1666 bool is_admin = capable(CAP_SYS_ADMIN);
1667 u16 count = same->dest_count;
1668 struct file *dst_file;
1672 if (!(file->f_mode & FMODE_READ))
1675 if (same->reserved1 || same->reserved2)
1678 off = same->src_offset;
1679 len = same->src_length;
1682 if (S_ISDIR(src->i_mode))
1686 if (!S_ISREG(src->i_mode))
1689 ret = clone_verify_area(file, off, len, false);
1694 /* pre-format output fields to sane values */
1695 for (i = 0; i < count; i++) {
1696 same->info[i].bytes_deduped = 0ULL;
1697 same->info[i].status = FILE_DEDUPE_RANGE_SAME;
1700 for (i = 0, info = same->info; i < count; i++, info++) {
1702 struct fd dst_fd = fdget(info->dest_fd);
1704 dst_file = dst_fd.file;
1706 info->status = -EBADF;
1709 dst = file_inode(dst_file);
1711 ret = mnt_want_write_file(dst_file);
1717 dst_off = info->dest_offset;
1718 ret = clone_verify_area(dst_file, dst_off, len, true);
1725 if (info->reserved) {
1726 info->status = -EINVAL;
1727 } else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) {
1728 info->status = -EINVAL;
1729 } else if (file->f_path.mnt != dst_file->f_path.mnt) {
1730 info->status = -EXDEV;
1731 } else if (S_ISDIR(dst->i_mode)) {
1732 info->status = -EISDIR;
1733 } else if (dst_file->f_op->dedupe_file_range == NULL) {
1734 info->status = -EINVAL;
1736 deduped = dst_file->f_op->dedupe_file_range(file, off,
1739 if (deduped == -EBADE)
1740 info->status = FILE_DEDUPE_RANGE_DIFFERS;
1741 else if (deduped < 0)
1742 info->status = deduped;
1744 info->bytes_deduped += deduped;
1748 mnt_drop_write_file(dst_file);
1752 if (fatal_signal_pending(current))
1759 EXPORT_SYMBOL(vfs_dedupe_file_range);