1 // SPDX-License-Identifier: GPL-2.0
3 * linux/fs/read_write.c
5 * Copyright (C) 1991, 1992 Linus Torvalds
8 #include <linux/slab.h>
9 #include <linux/stat.h>
10 #include <linux/sched/xacct.h>
11 #include <linux/fcntl.h>
12 #include <linux/file.h>
13 #include <linux/uio.h>
14 #include <linux/fsnotify.h>
15 #include <linux/security.h>
16 #include <linux/export.h>
17 #include <linux/syscalls.h>
18 #include <linux/pagemap.h>
19 #include <linux/splice.h>
20 #include <linux/compat.h>
21 #include <linux/mount.h>
25 #include <linux/uaccess.h>
26 #include <asm/unistd.h>
28 const struct file_operations generic_ro_fops = {
29 .llseek = generic_file_llseek,
30 .read_iter = generic_file_read_iter,
31 .mmap = generic_file_readonly_mmap,
32 .splice_read = generic_file_splice_read,
35 EXPORT_SYMBOL(generic_ro_fops);
37 static inline bool unsigned_offsets(struct file *file)
39 return file->f_mode & FMODE_UNSIGNED_OFFSET;
43 * vfs_setpos - update the file offset for lseek
44 * @file: file structure in question
45 * @offset: file offset to seek to
46 * @maxsize: maximum file size
48 * This is a low-level filesystem helper for updating the file offset to
49 * the value specified by @offset if the given offset is valid and it is
50 * not equal to the current file offset.
52 * Return the specified offset on success and -EINVAL on invalid offset.
54 loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)
56 if (offset < 0 && !unsigned_offsets(file))
61 if (offset != file->f_pos) {
67 EXPORT_SYMBOL(vfs_setpos);
70 * generic_file_llseek_size - generic llseek implementation for regular files
71 * @file: file structure to seek on
72 * @offset: file offset to seek to
73 * @whence: type of seek
74 * @size: max size of this file in file system
75 * @eof: offset used for SEEK_END position
77 * This is a variant of generic_file_llseek that allows passing in a custom
78 * maximum file size and a custom EOF position, for e.g. hashed directories
81 * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms)
82 * SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes.
83 * read/writes behave like SEEK_SET against seeks.
86 generic_file_llseek_size(struct file *file, loff_t offset, int whence,
87 loff_t maxsize, loff_t eof)
95 * Here we special-case the lseek(fd, 0, SEEK_CUR)
96 * position-querying operation. Avoid rewriting the "same"
97 * f_pos value back to the file because a concurrent read(),
98 * write() or lseek() might have altered it
103 * f_lock protects against read/modify/write race with other
104 * SEEK_CURs. Note that parallel writes and reads behave
107 spin_lock(&file->f_lock);
108 offset = vfs_setpos(file, file->f_pos + offset, maxsize);
109 spin_unlock(&file->f_lock);
113 * In the generic case the entire file is data, so as long as
114 * offset isn't at the end of the file then the offset is data.
116 if ((unsigned long long)offset >= eof)
121 * There is a virtual hole at the end of the file, so as long as
122 * offset isn't i_size or larger, return i_size.
124 if ((unsigned long long)offset >= eof)
130 return vfs_setpos(file, offset, maxsize);
132 EXPORT_SYMBOL(generic_file_llseek_size);
135 * generic_file_llseek - generic llseek implementation for regular files
136 * @file: file structure to seek on
137 * @offset: file offset to seek to
138 * @whence: type of seek
140 * This is a generic implemenation of ->llseek useable for all normal local
141 * filesystems. It just updates the file offset to the value specified by
142 * @offset and @whence.
144 loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)
146 struct inode *inode = file->f_mapping->host;
148 return generic_file_llseek_size(file, offset, whence,
149 inode->i_sb->s_maxbytes,
152 EXPORT_SYMBOL(generic_file_llseek);
155 * fixed_size_llseek - llseek implementation for fixed-sized devices
156 * @file: file structure to seek on
157 * @offset: file offset to seek to
158 * @whence: type of seek
159 * @size: size of the file
162 loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)
165 case SEEK_SET: case SEEK_CUR: case SEEK_END:
166 return generic_file_llseek_size(file, offset, whence,
172 EXPORT_SYMBOL(fixed_size_llseek);
175 * no_seek_end_llseek - llseek implementation for fixed-sized devices
176 * @file: file structure to seek on
177 * @offset: file offset to seek to
178 * @whence: type of seek
181 loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence)
184 case SEEK_SET: case SEEK_CUR:
185 return generic_file_llseek_size(file, offset, whence,
191 EXPORT_SYMBOL(no_seek_end_llseek);
194 * no_seek_end_llseek_size - llseek implementation for fixed-sized devices
195 * @file: file structure to seek on
196 * @offset: file offset to seek to
197 * @whence: type of seek
198 * @size: maximal offset allowed
201 loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size)
204 case SEEK_SET: case SEEK_CUR:
205 return generic_file_llseek_size(file, offset, whence,
211 EXPORT_SYMBOL(no_seek_end_llseek_size);
214 * noop_llseek - No Operation Performed llseek implementation
215 * @file: file structure to seek on
216 * @offset: file offset to seek to
217 * @whence: type of seek
219 * This is an implementation of ->llseek useable for the rare special case when
220 * userspace expects the seek to succeed but the (device) file is actually not
221 * able to perform the seek. In this case you use noop_llseek() instead of
222 * falling back to the default implementation of ->llseek.
224 loff_t noop_llseek(struct file *file, loff_t offset, int whence)
228 EXPORT_SYMBOL(noop_llseek);
230 loff_t no_llseek(struct file *file, loff_t offset, int whence)
234 EXPORT_SYMBOL(no_llseek);
236 loff_t default_llseek(struct file *file, loff_t offset, int whence)
238 struct inode *inode = file_inode(file);
244 offset += i_size_read(inode);
248 retval = file->f_pos;
251 offset += file->f_pos;
255 * In the generic case the entire file is data, so as
256 * long as offset isn't at the end of the file then the
259 if (offset >= inode->i_size) {
266 * There is a virtual hole at the end of the file, so
267 * as long as offset isn't i_size or larger, return
270 if (offset >= inode->i_size) {
274 offset = inode->i_size;
278 if (offset >= 0 || unsigned_offsets(file)) {
279 if (offset != file->f_pos) {
280 file->f_pos = offset;
289 EXPORT_SYMBOL(default_llseek);
291 loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
293 loff_t (*fn)(struct file *, loff_t, int);
296 if (file->f_mode & FMODE_LSEEK) {
297 if (file->f_op->llseek)
298 fn = file->f_op->llseek;
300 return fn(file, offset, whence);
302 EXPORT_SYMBOL(vfs_llseek);
304 off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence)
307 struct fd f = fdget_pos(fd);
312 if (whence <= SEEK_MAX) {
313 loff_t res = vfs_llseek(f.file, offset, whence);
315 if (res != (loff_t)retval)
316 retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */
322 SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
324 return ksys_lseek(fd, offset, whence);
328 COMPAT_SYSCALL_DEFINE3(lseek, unsigned int, fd, compat_off_t, offset, unsigned int, whence)
330 return ksys_lseek(fd, offset, whence);
334 #if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT)
335 SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
336 unsigned long, offset_low, loff_t __user *, result,
337 unsigned int, whence)
340 struct fd f = fdget_pos(fd);
347 if (whence > SEEK_MAX)
350 offset = vfs_llseek(f.file, ((loff_t) offset_high << 32) | offset_low,
353 retval = (int)offset;
356 if (!copy_to_user(result, &offset, sizeof(offset)))
365 int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
369 int retval = -EINVAL;
371 inode = file_inode(file);
372 if (unlikely((ssize_t) count < 0))
375 if (unlikely(pos < 0)) {
376 if (!unsigned_offsets(file))
378 if (count >= -pos) /* both values are in 0..LLONG_MAX */
380 } else if (unlikely((loff_t) (pos + count) < 0)) {
381 if (!unsigned_offsets(file))
385 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
386 retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
387 read_write == READ ? F_RDLCK : F_WRLCK);
391 return security_file_permission(file,
392 read_write == READ ? MAY_READ : MAY_WRITE);
395 static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
397 struct iovec iov = { .iov_base = buf, .iov_len = len };
399 struct iov_iter iter;
402 init_sync_kiocb(&kiocb, filp);
403 kiocb.ki_pos = *ppos;
404 iov_iter_init(&iter, READ, &iov, 1, len);
406 ret = call_read_iter(filp, &kiocb, &iter);
407 BUG_ON(ret == -EIOCBQUEUED);
408 *ppos = kiocb.ki_pos;
412 ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
415 if (file->f_op->read)
416 return file->f_op->read(file, buf, count, pos);
417 else if (file->f_op->read_iter)
418 return new_sync_read(file, buf, count, pos);
423 ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
430 /* The cast to a user pointer is valid due to the set_fs() */
431 result = vfs_read(file, (void __user *)buf, count, pos);
435 EXPORT_SYMBOL(kernel_read);
437 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
441 if (!(file->f_mode & FMODE_READ))
443 if (!(file->f_mode & FMODE_CAN_READ))
445 if (unlikely(!access_ok(buf, count)))
448 ret = rw_verify_area(READ, file, pos, count);
450 if (count > MAX_RW_COUNT)
451 count = MAX_RW_COUNT;
452 ret = __vfs_read(file, buf, count, pos);
454 fsnotify_access(file);
455 add_rchar(current, ret);
463 static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
465 struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
467 struct iov_iter iter;
470 init_sync_kiocb(&kiocb, filp);
471 kiocb.ki_pos = *ppos;
472 iov_iter_init(&iter, WRITE, &iov, 1, len);
474 ret = call_write_iter(filp, &kiocb, &iter);
475 BUG_ON(ret == -EIOCBQUEUED);
477 *ppos = kiocb.ki_pos;
481 static ssize_t __vfs_write(struct file *file, const char __user *p,
482 size_t count, loff_t *pos)
484 if (file->f_op->write)
485 return file->f_op->write(file, p, count, pos);
486 else if (file->f_op->write_iter)
487 return new_sync_write(file, p, count, pos);
492 ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
495 const char __user *p;
498 if (!(file->f_mode & FMODE_CAN_WRITE))
503 p = (__force const char __user *)buf;
504 if (count > MAX_RW_COUNT)
505 count = MAX_RW_COUNT;
506 ret = __vfs_write(file, p, count, pos);
509 fsnotify_modify(file);
510 add_wchar(current, ret);
515 EXPORT_SYMBOL(__kernel_write);
517 ssize_t kernel_write(struct file *file, const void *buf, size_t count,
525 /* The cast to a user pointer is valid due to the set_fs() */
526 res = vfs_write(file, (__force const char __user *)buf, count, pos);
531 EXPORT_SYMBOL(kernel_write);
533 ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
537 if (!(file->f_mode & FMODE_WRITE))
539 if (!(file->f_mode & FMODE_CAN_WRITE))
541 if (unlikely(!access_ok(buf, count)))
544 ret = rw_verify_area(WRITE, file, pos, count);
546 if (count > MAX_RW_COUNT)
547 count = MAX_RW_COUNT;
548 file_start_write(file);
549 ret = __vfs_write(file, buf, count, pos);
551 fsnotify_modify(file);
552 add_wchar(current, ret);
555 file_end_write(file);
561 static inline loff_t file_pos_read(struct file *file)
563 return file->f_mode & FMODE_STREAM ? 0 : file->f_pos;
566 static inline void file_pos_write(struct file *file, loff_t pos)
568 if ((file->f_mode & FMODE_STREAM) == 0)
572 ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count)
574 struct fd f = fdget_pos(fd);
575 ssize_t ret = -EBADF;
578 loff_t pos = file_pos_read(f.file);
579 ret = vfs_read(f.file, buf, count, &pos);
581 file_pos_write(f.file, pos);
587 SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
589 return ksys_read(fd, buf, count);
592 ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count)
594 struct fd f = fdget_pos(fd);
595 ssize_t ret = -EBADF;
598 loff_t pos = file_pos_read(f.file);
599 ret = vfs_write(f.file, buf, count, &pos);
601 file_pos_write(f.file, pos);
608 SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
611 return ksys_write(fd, buf, count);
614 ssize_t ksys_pread64(unsigned int fd, char __user *buf, size_t count,
618 ssize_t ret = -EBADF;
626 if (f.file->f_mode & FMODE_PREAD)
627 ret = vfs_read(f.file, buf, count, &pos);
634 SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
635 size_t, count, loff_t, pos)
637 return ksys_pread64(fd, buf, count, pos);
640 ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf,
641 size_t count, loff_t pos)
644 ssize_t ret = -EBADF;
652 if (f.file->f_mode & FMODE_PWRITE)
653 ret = vfs_write(f.file, buf, count, &pos);
660 SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
661 size_t, count, loff_t, pos)
663 return ksys_pwrite64(fd, buf, count, pos);
666 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
667 loff_t *ppos, int type, rwf_t flags)
672 init_sync_kiocb(&kiocb, filp);
673 ret = kiocb_set_rw_flags(&kiocb, flags);
676 kiocb.ki_pos = *ppos;
679 ret = call_read_iter(filp, &kiocb, iter);
681 ret = call_write_iter(filp, &kiocb, iter);
682 BUG_ON(ret == -EIOCBQUEUED);
683 *ppos = kiocb.ki_pos;
687 /* Do it by hand, with file-ops */
688 static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
689 loff_t *ppos, int type, rwf_t flags)
693 if (flags & ~RWF_HIPRI)
696 while (iov_iter_count(iter)) {
697 struct iovec iovec = iov_iter_iovec(iter);
701 nr = filp->f_op->read(filp, iovec.iov_base,
702 iovec.iov_len, ppos);
704 nr = filp->f_op->write(filp, iovec.iov_base,
705 iovec.iov_len, ppos);
714 if (nr != iovec.iov_len)
716 iov_iter_advance(iter, nr);
723 * rw_copy_check_uvector() - Copy an array of &struct iovec from userspace
724 * into the kernel and check that it is valid.
726 * @type: One of %CHECK_IOVEC_ONLY, %READ, or %WRITE.
727 * @uvector: Pointer to the userspace array.
728 * @nr_segs: Number of elements in userspace array.
729 * @fast_segs: Number of elements in @fast_pointer.
730 * @fast_pointer: Pointer to (usually small on-stack) kernel array.
731 * @ret_pointer: (output parameter) Pointer to a variable that will point to
732 * either @fast_pointer, a newly allocated kernel array, or NULL,
733 * depending on which array was used.
735 * This function copies an array of &struct iovec of @nr_segs from
736 * userspace into the kernel and checks that each element is valid (e.g.
737 * it does not point to a kernel address or cause overflow by being too
740 * As an optimization, the caller may provide a pointer to a small
741 * on-stack array in @fast_pointer, typically %UIO_FASTIOV elements long
742 * (the size of this array, or 0 if unused, should be given in @fast_segs).
744 * @ret_pointer will always point to the array that was used, so the
745 * caller must take care not to call kfree() on it e.g. in case the
746 * @fast_pointer array was used and it was allocated on the stack.
748 * Return: The total number of bytes covered by the iovec array on success
749 * or a negative error code on error.
751 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
752 unsigned long nr_segs, unsigned long fast_segs,
753 struct iovec *fast_pointer,
754 struct iovec **ret_pointer)
758 struct iovec *iov = fast_pointer;
761 * SuS says "The readv() function *may* fail if the iovcnt argument
762 * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
763 * traditionally returned zero for zero segments, so...
771 * First get the "struct iovec" from user memory and
772 * verify all the pointers
774 if (nr_segs > UIO_MAXIOV) {
778 if (nr_segs > fast_segs) {
779 iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL);
785 if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
791 * According to the Single Unix Specification we should return EINVAL
792 * if an element length is < 0 when cast to ssize_t or if the
793 * total length would overflow the ssize_t return value of the
796 * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
800 for (seg = 0; seg < nr_segs; seg++) {
801 void __user *buf = iov[seg].iov_base;
802 ssize_t len = (ssize_t)iov[seg].iov_len;
804 /* see if we we're about to use an invalid len or if
805 * it's about to overflow ssize_t */
811 && unlikely(!access_ok(buf, len))) {
815 if (len > MAX_RW_COUNT - ret) {
816 len = MAX_RW_COUNT - ret;
817 iov[seg].iov_len = len;
827 ssize_t compat_rw_copy_check_uvector(int type,
828 const struct compat_iovec __user *uvector, unsigned long nr_segs,
829 unsigned long fast_segs, struct iovec *fast_pointer,
830 struct iovec **ret_pointer)
832 compat_ssize_t tot_len;
833 struct iovec *iov = *ret_pointer = fast_pointer;
838 * SuS says "The readv() function *may* fail if the iovcnt argument
839 * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
840 * traditionally returned zero for zero segments, so...
846 if (nr_segs > UIO_MAXIOV)
848 if (nr_segs > fast_segs) {
850 iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL);
857 if (!access_ok(uvector, nr_segs*sizeof(*uvector)))
861 * Single unix specification:
862 * We should -EINVAL if an element length is not >= 0 and fitting an
865 * In Linux, the total length is limited to MAX_RW_COUNT, there is
866 * no overflow possibility.
870 for (seg = 0; seg < nr_segs; seg++) {
874 if (__get_user(len, &uvector->iov_len) ||
875 __get_user(buf, &uvector->iov_base)) {
879 if (len < 0) /* size_t not fitting in compat_ssize_t .. */
882 !access_ok(compat_ptr(buf), len)) {
886 if (len > MAX_RW_COUNT - tot_len)
887 len = MAX_RW_COUNT - tot_len;
889 iov->iov_base = compat_ptr(buf);
890 iov->iov_len = (compat_size_t) len;
901 static ssize_t do_iter_read(struct file *file, struct iov_iter *iter,
902 loff_t *pos, rwf_t flags)
907 if (!(file->f_mode & FMODE_READ))
909 if (!(file->f_mode & FMODE_CAN_READ))
912 tot_len = iov_iter_count(iter);
915 ret = rw_verify_area(READ, file, pos, tot_len);
919 if (file->f_op->read_iter)
920 ret = do_iter_readv_writev(file, iter, pos, READ, flags);
922 ret = do_loop_readv_writev(file, iter, pos, READ, flags);
925 fsnotify_access(file);
929 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
932 if (!file->f_op->read_iter)
934 return do_iter_read(file, iter, ppos, flags);
936 EXPORT_SYMBOL(vfs_iter_read);
938 static ssize_t do_iter_write(struct file *file, struct iov_iter *iter,
939 loff_t *pos, rwf_t flags)
944 if (!(file->f_mode & FMODE_WRITE))
946 if (!(file->f_mode & FMODE_CAN_WRITE))
949 tot_len = iov_iter_count(iter);
952 ret = rw_verify_area(WRITE, file, pos, tot_len);
956 if (file->f_op->write_iter)
957 ret = do_iter_readv_writev(file, iter, pos, WRITE, flags);
959 ret = do_loop_readv_writev(file, iter, pos, WRITE, flags);
961 fsnotify_modify(file);
965 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
968 if (!file->f_op->write_iter)
970 return do_iter_write(file, iter, ppos, flags);
972 EXPORT_SYMBOL(vfs_iter_write);
974 ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
975 unsigned long vlen, loff_t *pos, rwf_t flags)
977 struct iovec iovstack[UIO_FASTIOV];
978 struct iovec *iov = iovstack;
979 struct iov_iter iter;
982 ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
984 ret = do_iter_read(file, &iter, pos, flags);
991 static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
992 unsigned long vlen, loff_t *pos, rwf_t flags)
994 struct iovec iovstack[UIO_FASTIOV];
995 struct iovec *iov = iovstack;
996 struct iov_iter iter;
999 ret = import_iovec(WRITE, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
1001 file_start_write(file);
1002 ret = do_iter_write(file, &iter, pos, flags);
1003 file_end_write(file);
1009 static ssize_t do_readv(unsigned long fd, const struct iovec __user *vec,
1010 unsigned long vlen, rwf_t flags)
1012 struct fd f = fdget_pos(fd);
1013 ssize_t ret = -EBADF;
1016 loff_t pos = file_pos_read(f.file);
1017 ret = vfs_readv(f.file, vec, vlen, &pos, flags);
1019 file_pos_write(f.file, pos);
1024 add_rchar(current, ret);
1029 static ssize_t do_writev(unsigned long fd, const struct iovec __user *vec,
1030 unsigned long vlen, rwf_t flags)
1032 struct fd f = fdget_pos(fd);
1033 ssize_t ret = -EBADF;
1036 loff_t pos = file_pos_read(f.file);
1037 ret = vfs_writev(f.file, vec, vlen, &pos, flags);
1039 file_pos_write(f.file, pos);
1044 add_wchar(current, ret);
1049 static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
1051 #define HALF_LONG_BITS (BITS_PER_LONG / 2)
1052 return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
1055 static ssize_t do_preadv(unsigned long fd, const struct iovec __user *vec,
1056 unsigned long vlen, loff_t pos, rwf_t flags)
1059 ssize_t ret = -EBADF;
1067 if (f.file->f_mode & FMODE_PREAD)
1068 ret = vfs_readv(f.file, vec, vlen, &pos, flags);
1073 add_rchar(current, ret);
1078 static ssize_t do_pwritev(unsigned long fd, const struct iovec __user *vec,
1079 unsigned long vlen, loff_t pos, rwf_t flags)
1082 ssize_t ret = -EBADF;
1090 if (f.file->f_mode & FMODE_PWRITE)
1091 ret = vfs_writev(f.file, vec, vlen, &pos, flags);
1096 add_wchar(current, ret);
1101 SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
1102 unsigned long, vlen)
1104 return do_readv(fd, vec, vlen, 0);
1107 SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
1108 unsigned long, vlen)
1110 return do_writev(fd, vec, vlen, 0);
1113 SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
1114 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
1116 loff_t pos = pos_from_hilo(pos_h, pos_l);
1118 return do_preadv(fd, vec, vlen, pos, 0);
1121 SYSCALL_DEFINE6(preadv2, unsigned long, fd, const struct iovec __user *, vec,
1122 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
1125 loff_t pos = pos_from_hilo(pos_h, pos_l);
1128 return do_readv(fd, vec, vlen, flags);
1130 return do_preadv(fd, vec, vlen, pos, flags);
1133 SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
1134 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
1136 loff_t pos = pos_from_hilo(pos_h, pos_l);
1138 return do_pwritev(fd, vec, vlen, pos, 0);
1141 SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
1142 unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h,
1145 loff_t pos = pos_from_hilo(pos_h, pos_l);
1148 return do_writev(fd, vec, vlen, flags);
1150 return do_pwritev(fd, vec, vlen, pos, flags);
1153 #ifdef CONFIG_COMPAT
1154 static size_t compat_readv(struct file *file,
1155 const struct compat_iovec __user *vec,
1156 unsigned long vlen, loff_t *pos, rwf_t flags)
1158 struct iovec iovstack[UIO_FASTIOV];
1159 struct iovec *iov = iovstack;
1160 struct iov_iter iter;
1163 ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter);
1165 ret = do_iter_read(file, &iter, pos, flags);
1169 add_rchar(current, ret);
1174 static size_t do_compat_readv(compat_ulong_t fd,
1175 const struct compat_iovec __user *vec,
1176 compat_ulong_t vlen, rwf_t flags)
1178 struct fd f = fdget_pos(fd);
1184 pos = f.file->f_pos;
1185 ret = compat_readv(f.file, vec, vlen, &pos, flags);
1187 f.file->f_pos = pos;
1193 COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
1194 const struct compat_iovec __user *,vec,
1195 compat_ulong_t, vlen)
1197 return do_compat_readv(fd, vec, vlen, 0);
1200 static long do_compat_preadv64(unsigned long fd,
1201 const struct compat_iovec __user *vec,
1202 unsigned long vlen, loff_t pos, rwf_t flags)
1213 if (f.file->f_mode & FMODE_PREAD)
1214 ret = compat_readv(f.file, vec, vlen, &pos, flags);
1219 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
1220 COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
1221 const struct compat_iovec __user *,vec,
1222 unsigned long, vlen, loff_t, pos)
1224 return do_compat_preadv64(fd, vec, vlen, pos, 0);
1228 COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
1229 const struct compat_iovec __user *,vec,
1230 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1232 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1234 return do_compat_preadv64(fd, vec, vlen, pos, 0);
1237 #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
1238 COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
1239 const struct compat_iovec __user *,vec,
1240 unsigned long, vlen, loff_t, pos, rwf_t, flags)
1243 return do_compat_readv(fd, vec, vlen, flags);
1245 return do_compat_preadv64(fd, vec, vlen, pos, flags);
1249 COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
1250 const struct compat_iovec __user *,vec,
1251 compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
1254 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1257 return do_compat_readv(fd, vec, vlen, flags);
1259 return do_compat_preadv64(fd, vec, vlen, pos, flags);
1262 static size_t compat_writev(struct file *file,
1263 const struct compat_iovec __user *vec,
1264 unsigned long vlen, loff_t *pos, rwf_t flags)
1266 struct iovec iovstack[UIO_FASTIOV];
1267 struct iovec *iov = iovstack;
1268 struct iov_iter iter;
1271 ret = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter);
1273 file_start_write(file);
1274 ret = do_iter_write(file, &iter, pos, flags);
1275 file_end_write(file);
1279 add_wchar(current, ret);
1284 static size_t do_compat_writev(compat_ulong_t fd,
1285 const struct compat_iovec __user* vec,
1286 compat_ulong_t vlen, rwf_t flags)
1288 struct fd f = fdget_pos(fd);
1294 pos = f.file->f_pos;
1295 ret = compat_writev(f.file, vec, vlen, &pos, flags);
1297 f.file->f_pos = pos;
1302 COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
1303 const struct compat_iovec __user *, vec,
1304 compat_ulong_t, vlen)
1306 return do_compat_writev(fd, vec, vlen, 0);
1309 static long do_compat_pwritev64(unsigned long fd,
1310 const struct compat_iovec __user *vec,
1311 unsigned long vlen, loff_t pos, rwf_t flags)
1322 if (f.file->f_mode & FMODE_PWRITE)
1323 ret = compat_writev(f.file, vec, vlen, &pos, flags);
1328 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
1329 COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
1330 const struct compat_iovec __user *,vec,
1331 unsigned long, vlen, loff_t, pos)
1333 return do_compat_pwritev64(fd, vec, vlen, pos, 0);
1337 COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
1338 const struct compat_iovec __user *,vec,
1339 compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
1341 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1343 return do_compat_pwritev64(fd, vec, vlen, pos, 0);
1346 #ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
1347 COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
1348 const struct compat_iovec __user *,vec,
1349 unsigned long, vlen, loff_t, pos, rwf_t, flags)
1352 return do_compat_writev(fd, vec, vlen, flags);
1354 return do_compat_pwritev64(fd, vec, vlen, pos, flags);
1358 COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
1359 const struct compat_iovec __user *,vec,
1360 compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags)
1362 loff_t pos = ((loff_t)pos_high << 32) | pos_low;
1365 return do_compat_writev(fd, vec, vlen, flags);
1367 return do_compat_pwritev64(fd, vec, vlen, pos, flags);
1372 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
1373 size_t count, loff_t max)
1376 struct inode *in_inode, *out_inode;
1383 * Get input file, and verify that it is ok..
1389 if (!(in.file->f_mode & FMODE_READ))
1393 pos = in.file->f_pos;
1396 if (!(in.file->f_mode & FMODE_PREAD))
1399 retval = rw_verify_area(READ, in.file, &pos, count);
1402 if (count > MAX_RW_COUNT)
1403 count = MAX_RW_COUNT;
1406 * Get output file, and verify that it is ok..
1409 out = fdget(out_fd);
1412 if (!(out.file->f_mode & FMODE_WRITE))
1414 in_inode = file_inode(in.file);
1415 out_inode = file_inode(out.file);
1416 out_pos = out.file->f_pos;
1417 retval = rw_verify_area(WRITE, out.file, &out_pos, count);
1422 max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
1424 if (unlikely(pos + count > max)) {
1425 retval = -EOVERFLOW;
1434 * We need to debate whether we can enable this or not. The
1435 * man page documents EAGAIN return for the output at least,
1436 * and the application is arguably buggy if it doesn't expect
1437 * EAGAIN on a non-blocking file descriptor.
1439 if (in.file->f_flags & O_NONBLOCK)
1440 fl = SPLICE_F_NONBLOCK;
1442 file_start_write(out.file);
1443 retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
1444 file_end_write(out.file);
1447 add_rchar(current, retval);
1448 add_wchar(current, retval);
1449 fsnotify_access(in.file);
1450 fsnotify_modify(out.file);
1451 out.file->f_pos = out_pos;
1455 in.file->f_pos = pos;
1461 retval = -EOVERFLOW;
1471 SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
1478 if (unlikely(get_user(off, offset)))
1481 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1482 if (unlikely(put_user(pos, offset)))
1487 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1490 SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
1496 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1498 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1499 if (unlikely(put_user(pos, offset)))
1504 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1507 #ifdef CONFIG_COMPAT
1508 COMPAT_SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd,
1509 compat_off_t __user *, offset, compat_size_t, count)
1516 if (unlikely(get_user(off, offset)))
1519 ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS);
1520 if (unlikely(put_user(pos, offset)))
1525 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1528 COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
1529 compat_loff_t __user *, offset, compat_size_t, count)
1535 if (unlikely(copy_from_user(&pos, offset, sizeof(loff_t))))
1537 ret = do_sendfile(out_fd, in_fd, &pos, count, 0);
1538 if (unlikely(put_user(pos, offset)))
1543 return do_sendfile(out_fd, in_fd, NULL, count, 0);
1548 * copy_file_range() differs from regular file read and write in that it
1549 * specifically allows return partial success. When it does so is up to
1550 * the copy_file_range method.
1552 ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
1553 struct file *file_out, loff_t pos_out,
1554 size_t len, unsigned int flags)
1556 struct inode *inode_in = file_inode(file_in);
1557 struct inode *inode_out = file_inode(file_out);
1563 if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
1565 if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
1568 ret = rw_verify_area(READ, file_in, &pos_in, len);
1572 ret = rw_verify_area(WRITE, file_out, &pos_out, len);
1576 if (!(file_in->f_mode & FMODE_READ) ||
1577 !(file_out->f_mode & FMODE_WRITE) ||
1578 (file_out->f_flags & O_APPEND))
1581 /* this could be relaxed once a method supports cross-fs copies */
1582 if (inode_in->i_sb != inode_out->i_sb)
1588 file_start_write(file_out);
1591 * Try cloning first, this is supported by more file systems, and
1592 * more efficient if both clone and copy are supported (e.g. NFS).
1594 if (file_in->f_op->remap_file_range) {
1597 cloned = file_in->f_op->remap_file_range(file_in, pos_in,
1599 min_t(loff_t, MAX_RW_COUNT, len),
1600 REMAP_FILE_CAN_SHORTEN);
1607 if (file_out->f_op->copy_file_range) {
1608 ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
1609 pos_out, len, flags);
1610 if (ret != -EOPNOTSUPP)
1614 ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
1615 len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
1619 fsnotify_access(file_in);
1620 add_rchar(current, ret);
1621 fsnotify_modify(file_out);
1622 add_wchar(current, ret);
1628 file_end_write(file_out);
1632 EXPORT_SYMBOL(vfs_copy_file_range);
1634 SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in,
1635 int, fd_out, loff_t __user *, off_out,
1636 size_t, len, unsigned int, flags)
1642 ssize_t ret = -EBADF;
1644 f_in = fdget(fd_in);
1648 f_out = fdget(fd_out);
1654 if (copy_from_user(&pos_in, off_in, sizeof(loff_t)))
1657 pos_in = f_in.file->f_pos;
1661 if (copy_from_user(&pos_out, off_out, sizeof(loff_t)))
1664 pos_out = f_out.file->f_pos;
1667 ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len,
1674 if (copy_to_user(off_in, &pos_in, sizeof(loff_t)))
1677 f_in.file->f_pos = pos_in;
1681 if (copy_to_user(off_out, &pos_out, sizeof(loff_t)))
1684 f_out.file->f_pos = pos_out;
1696 static int remap_verify_area(struct file *file, loff_t pos, loff_t len,
1699 struct inode *inode = file_inode(file);
1701 if (unlikely(pos < 0 || len < 0))
1704 if (unlikely((loff_t) (pos + len) < 0))
1707 if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
1708 loff_t end = len ? pos + len - 1 : OFFSET_MAX;
1711 retval = locks_mandatory_area(inode, file, pos, end,
1712 write ? F_WRLCK : F_RDLCK);
1717 return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
1720 * Ensure that we don't remap a partial EOF block in the middle of something
1721 * else. Assume that the offsets have already been checked for block
1724 * For deduplication we always scale down to the previous block because we
1725 * can't meaningfully compare post-EOF contents.
1727 * For clone we only link a partial EOF block above the destination file's EOF.
1729 * Shorten the request if possible.
1731 static int generic_remap_check_len(struct inode *inode_in,
1732 struct inode *inode_out,
1735 unsigned int remap_flags)
1737 u64 blkmask = i_blocksize(inode_in) - 1;
1738 loff_t new_len = *len;
1740 if ((*len & blkmask) == 0)
1743 if ((remap_flags & REMAP_FILE_DEDUP) ||
1744 pos_out + *len < i_size_read(inode_out))
1745 new_len &= ~blkmask;
1747 if (new_len == *len)
1750 if (remap_flags & REMAP_FILE_CAN_SHORTEN) {
1755 return (remap_flags & REMAP_FILE_DEDUP) ? -EBADE : -EINVAL;
1759 * Read a page's worth of file data into the page cache. Return the page
1762 static struct page *vfs_dedupe_get_page(struct inode *inode, loff_t offset)
1766 page = read_mapping_page(inode->i_mapping, offset >> PAGE_SHIFT, NULL);
1769 if (!PageUptodate(page)) {
1771 return ERR_PTR(-EIO);
1778 * Compare extents of two files to see if they are the same.
1779 * Caller must have locked both inodes to prevent write races.
1781 static int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
1782 struct inode *dest, loff_t destoff,
1783 loff_t len, bool *is_same)
1789 struct page *src_page;
1790 struct page *dest_page;
1798 src_poff = srcoff & (PAGE_SIZE - 1);
1799 dest_poff = destoff & (PAGE_SIZE - 1);
1800 cmp_len = min(PAGE_SIZE - src_poff,
1801 PAGE_SIZE - dest_poff);
1802 cmp_len = min(cmp_len, len);
1806 src_page = vfs_dedupe_get_page(src, srcoff);
1807 if (IS_ERR(src_page)) {
1808 error = PTR_ERR(src_page);
1811 dest_page = vfs_dedupe_get_page(dest, destoff);
1812 if (IS_ERR(dest_page)) {
1813 error = PTR_ERR(dest_page);
1814 unlock_page(src_page);
1818 src_addr = kmap_atomic(src_page);
1819 dest_addr = kmap_atomic(dest_page);
1821 flush_dcache_page(src_page);
1822 flush_dcache_page(dest_page);
1824 if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len))
1827 kunmap_atomic(dest_addr);
1828 kunmap_atomic(src_addr);
1829 unlock_page(dest_page);
1830 unlock_page(src_page);
1831 put_page(dest_page);
1850 * Check that the two inodes are eligible for cloning, the ranges make
1851 * sense, and then flush all dirty data. Caller must ensure that the
1852 * inodes have been locked against any other modifications.
1854 * If there's an error, then the usual negative error code is returned.
1855 * Otherwise returns 0 with *len set to the request length.
1857 int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
1858 struct file *file_out, loff_t pos_out,
1859 loff_t *len, unsigned int remap_flags)
1861 struct inode *inode_in = file_inode(file_in);
1862 struct inode *inode_out = file_inode(file_out);
1863 bool same_inode = (inode_in == inode_out);
1866 /* Don't touch certain kinds of inodes */
1867 if (IS_IMMUTABLE(inode_out))
1870 if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
1873 /* Don't reflink dirs, pipes, sockets... */
1874 if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
1876 if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
1879 /* Zero length dedupe exits immediately; reflink goes to EOF. */
1881 loff_t isize = i_size_read(inode_in);
1883 if ((remap_flags & REMAP_FILE_DEDUP) || pos_in == isize)
1887 *len = isize - pos_in;
1892 /* Check that we don't violate system file offset limits. */
1893 ret = generic_remap_checks(file_in, pos_in, file_out, pos_out, len,
1898 /* Wait for the completion of any pending IOs on both files */
1899 inode_dio_wait(inode_in);
1901 inode_dio_wait(inode_out);
1903 ret = filemap_write_and_wait_range(inode_in->i_mapping,
1904 pos_in, pos_in + *len - 1);
1908 ret = filemap_write_and_wait_range(inode_out->i_mapping,
1909 pos_out, pos_out + *len - 1);
1914 * Check that the extents are the same.
1916 if (remap_flags & REMAP_FILE_DEDUP) {
1917 bool is_same = false;
1919 ret = vfs_dedupe_file_range_compare(inode_in, pos_in,
1920 inode_out, pos_out, *len, &is_same);
1927 ret = generic_remap_check_len(inode_in, inode_out, pos_out, len,
1932 /* If can't alter the file contents, we're done. */
1933 if (!(remap_flags & REMAP_FILE_DEDUP)) {
1934 /* Update the timestamps, since we can alter file contents. */
1935 if (!(file_out->f_mode & FMODE_NOCMTIME)) {
1936 ret = file_update_time(file_out);
1942 * Clear the security bits if the process is not being run by
1943 * root. This keeps people from modifying setuid and setgid
1946 ret = file_remove_privs(file_out);
1953 EXPORT_SYMBOL(generic_remap_file_range_prep);
1955 loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
1956 struct file *file_out, loff_t pos_out,
1957 loff_t len, unsigned int remap_flags)
1959 struct inode *inode_in = file_inode(file_in);
1960 struct inode *inode_out = file_inode(file_out);
1963 WARN_ON_ONCE(remap_flags & REMAP_FILE_DEDUP);
1965 if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
1967 if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
1971 * FICLONE/FICLONERANGE ioctls enforce that src and dest files are on
1972 * the same mount. Practically, they only need to be on the same file
1975 if (inode_in->i_sb != inode_out->i_sb)
1978 if (!(file_in->f_mode & FMODE_READ) ||
1979 !(file_out->f_mode & FMODE_WRITE) ||
1980 (file_out->f_flags & O_APPEND))
1983 if (!file_in->f_op->remap_file_range)
1986 ret = remap_verify_area(file_in, pos_in, len, false);
1990 ret = remap_verify_area(file_out, pos_out, len, true);
1994 ret = file_in->f_op->remap_file_range(file_in, pos_in,
1995 file_out, pos_out, len, remap_flags);
1999 fsnotify_access(file_in);
2000 fsnotify_modify(file_out);
2003 EXPORT_SYMBOL(do_clone_file_range);
2005 loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
2006 struct file *file_out, loff_t pos_out,
2007 loff_t len, unsigned int remap_flags)
2011 file_start_write(file_out);
2012 ret = do_clone_file_range(file_in, pos_in, file_out, pos_out, len,
2014 file_end_write(file_out);
2018 EXPORT_SYMBOL(vfs_clone_file_range);
2020 /* Check whether we are allowed to dedupe the destination file */
2021 static bool allow_file_dedupe(struct file *file)
2023 if (capable(CAP_SYS_ADMIN))
2025 if (file->f_mode & FMODE_WRITE)
2027 if (uid_eq(current_fsuid(), file_inode(file)->i_uid))
2029 if (!inode_permission(file_inode(file), MAY_WRITE))
2034 loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
2035 struct file *dst_file, loff_t dst_pos,
2036 loff_t len, unsigned int remap_flags)
2040 WARN_ON_ONCE(remap_flags & ~(REMAP_FILE_DEDUP |
2041 REMAP_FILE_CAN_SHORTEN));
2043 ret = mnt_want_write_file(dst_file);
2047 ret = remap_verify_area(dst_file, dst_pos, len, true);
2049 goto out_drop_write;
2052 if (!allow_file_dedupe(dst_file))
2053 goto out_drop_write;
2056 if (src_file->f_path.mnt != dst_file->f_path.mnt)
2057 goto out_drop_write;
2060 if (S_ISDIR(file_inode(dst_file)->i_mode))
2061 goto out_drop_write;
2064 if (!dst_file->f_op->remap_file_range)
2065 goto out_drop_write;
2069 goto out_drop_write;
2072 ret = dst_file->f_op->remap_file_range(src_file, src_pos, dst_file,
2073 dst_pos, len, remap_flags | REMAP_FILE_DEDUP);
2075 mnt_drop_write_file(dst_file);
2079 EXPORT_SYMBOL(vfs_dedupe_file_range_one);
2081 int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
2083 struct file_dedupe_range_info *info;
2084 struct inode *src = file_inode(file);
2089 u16 count = same->dest_count;
2092 if (!(file->f_mode & FMODE_READ))
2095 if (same->reserved1 || same->reserved2)
2098 off = same->src_offset;
2099 len = same->src_length;
2101 if (S_ISDIR(src->i_mode))
2104 if (!S_ISREG(src->i_mode))
2107 if (!file->f_op->remap_file_range)
2110 ret = remap_verify_area(file, off, len, false);
2115 if (off + len > i_size_read(src))
2118 /* Arbitrary 1G limit on a single dedupe request, can be raised. */
2119 len = min_t(u64, len, 1 << 30);
2121 /* pre-format output fields to sane values */
2122 for (i = 0; i < count; i++) {
2123 same->info[i].bytes_deduped = 0ULL;
2124 same->info[i].status = FILE_DEDUPE_RANGE_SAME;
2127 for (i = 0, info = same->info; i < count; i++, info++) {
2128 struct fd dst_fd = fdget(info->dest_fd);
2129 struct file *dst_file = dst_fd.file;
2132 info->status = -EBADF;
2136 if (info->reserved) {
2137 info->status = -EINVAL;
2141 deduped = vfs_dedupe_file_range_one(file, off, dst_file,
2142 info->dest_offset, len,
2143 REMAP_FILE_CAN_SHORTEN);
2144 if (deduped == -EBADE)
2145 info->status = FILE_DEDUPE_RANGE_DIFFERS;
2146 else if (deduped < 0)
2147 info->status = deduped;
2149 info->bytes_deduped = len;
2154 if (fatal_signal_pending(current))
2159 EXPORT_SYMBOL(vfs_dedupe_file_range);