12 #include <linux/file.h>
37 static inline bool unsigned_offsets(struct file *file)  in unsigned_offsets()  argument
39 	return file->f_op->fop_flags & FOP_UNSIGNED_OFFSET;  in unsigned_offsets()
43  * vfs_setpos_cookie - update the file offset for lseek and reset cookie
44  * @file:	file structure in question
45  * @offset:	file offset to seek to
46  * @maxsize:	maximum file size
49  * Update the file offset to the value specified by @offset if the given
50  * offset is valid and it is not equal to the current file offset and
55 static loff_t vfs_setpos_cookie(struct file *file, loff_t offset,  in vfs_setpos_cookie()  argument
58 	if (offset < 0 && !unsigned_offsets(file))  in vfs_setpos_cookie()
63 	if (offset != file->f_pos) {  in vfs_setpos_cookie()
64 		file->f_pos = offset;  in vfs_setpos_cookie()
72  * vfs_setpos - update the file offset for lseek
73  * @file:	file structure in question
74  * @offset:	file offset to seek to
75  * @maxsize:	maximum file size
77  * This is a low-level filesystem helper for updating the file offset to
79  * not equal to the current file offset.
83 loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize)  in vfs_setpos()  argument
85 	return vfs_setpos_cookie(file, offset, maxsize, NULL);  in vfs_setpos()
91  * @file: file to seek on
94  * @eof: end of file
102 static int must_set_pos(struct file *file, loff_t *offset, int whence, loff_t eof)  in must_set_pos()  argument
112 		 * f_pos value back to the file because a concurrent read(),  in must_set_pos()
116 			*offset = file->f_pos;  in must_set_pos()
122 		 * In the generic case the entire file is data, so as long as  in must_set_pos()
123 		 * offset isn't at the end of the file then the offset is data.  in must_set_pos()
130 		 * There is a virtual hole at the end of the file, so as long as  in must_set_pos()
144  * @file:	file structure to seek on
145  * @offset:	file offset to seek to
147  * @maxsize:	max size of this file in file system
151  * maximum file size and a custom EOF position, for e.g. hashed directories
159 generic_file_llseek_size(struct file *file, loff_t offset, int whence,  in generic_file_llseek_size()  argument
164 	ret = must_set_pos(file, &offset, whence, eof);  in generic_file_llseek_size()
176 		guard(spinlock)(&file->f_lock);  in generic_file_llseek_size()
177 		return vfs_setpos(file, file->f_pos + offset, maxsize);  in generic_file_llseek_size()
180 	return vfs_setpos(file, offset, maxsize);  in generic_file_llseek_size()
186  * @file:	file structure to seek on
187  * @offset:	file offset to seek to
196 loff_t generic_llseek_cookie(struct file *file, loff_t offset, int whence,  in generic_llseek_cookie()  argument
199 	struct inode *inode = file->f_mapping->host;  in generic_llseek_cookie()
212 	if (WARN_ON_ONCE(!(file->f_mode & FMODE_ATOMIC_POS)))  in generic_llseek_cookie()
215 	ret = must_set_pos(file, &offset, whence, eof);  in generic_llseek_cookie()
223 		return vfs_setpos_cookie(file, file->f_pos + offset, maxsize, cookie);  in generic_llseek_cookie()
225 	return vfs_setpos_cookie(file, offset, maxsize, cookie);  in generic_llseek_cookie()
231  * @file:	file structure to seek on
232  * @offset:	file offset to seek to
236  * filesystems.  It just updates the file offset to the value specified by
239 loff_t generic_file_llseek(struct file *file, loff_t offset, int whence)  in generic_file_llseek()  argument
241 	struct inode *inode = file->f_mapping->host;  in generic_file_llseek()
243 	return generic_file_llseek_size(file, offset, whence,  in generic_file_llseek()
251  * @file:	file structure to seek on
252  * @offset:	file offset to seek to
254  * @size:	size of the file
257 loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size)  in fixed_size_llseek()  argument
261 		return generic_file_llseek_size(file, offset, whence,  in fixed_size_llseek()
271  * @file:	file structure to seek on
272  * @offset:	file offset to seek to
276 loff_t no_seek_end_llseek(struct file *file, loff_t offset, int whence)  in no_seek_end_llseek()  argument
280 		return generic_file_llseek_size(file, offset, whence,  in no_seek_end_llseek()
290  * @file:	file structure to seek on
291  * @offset:	file offset to seek to
296 loff_t no_seek_end_llseek_size(struct file *file, loff_t offset, int whence, loff_t size)  in no_seek_end_llseek_size()  argument
300 		return generic_file_llseek_size(file, offset, whence,  in no_seek_end_llseek_size()
310  * @file:	file structure to seek on
311  * @offset:	file offset to seek to
315  * userspace expects the seek to succeed but the (device) file is actually not
319 loff_t noop_llseek(struct file *file, loff_t offset, int whence)  in noop_llseek()  argument
321 	return file->f_pos;  in noop_llseek()
325 loff_t default_llseek(struct file *file, loff_t offset, int whence)  in default_llseek()  argument
327 	struct inode *inode = file_inode(file);  in default_llseek()
337 				retval = file->f_pos;  in default_llseek()
340 			offset += file->f_pos;  in default_llseek()
344 			 * In the generic case the entire file is data, so as  in default_llseek()
345 			 * long as offset isn't at the end of the file then the  in default_llseek()
355 			 * There is a virtual hole at the end of the file, so  in default_llseek()
367 	if (offset >= 0 || unsigned_offsets(file)) {  in default_llseek()
368 		if (offset != file->f_pos)  in default_llseek()
369 			file->f_pos = offset;  in default_llseek()
378 loff_t vfs_llseek(struct file *file, loff_t offset, int whence)  in vfs_llseek()  argument
380 	if (!(file->f_mode & FMODE_LSEEK))  in vfs_llseek()
382 	return file->f_op->llseek(file, offset, whence);  in vfs_llseek()
444 int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)  in rw_verify_area()  argument
456 			if (!unsigned_offsets(file))  in rw_verify_area()
461 			if (!unsigned_offsets(file))  in rw_verify_area()
466 	ret = security_file_permission(file, mask);  in rw_verify_area()
470 	return fsnotify_file_area_perm(file, mask, ppos, count);  in rw_verify_area()
474 static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)  in new_sync_read()
491 static int warn_unsupported(struct file *file, const char *op)  in warn_unsupported()  argument
494 		"kernel %s not supported for file %pD4 (pid: %d comm: %.20s)\n",  in warn_unsupported()
495 		op, file, current->pid, current->comm);  in warn_unsupported()
499 ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)  in __kernel_read()  argument
509 	if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ)))  in __kernel_read()
511 	if (!(file->f_mode & FMODE_CAN_READ))  in __kernel_read()
517 	if (unlikely(!file->f_op->read_iter || file->f_op->read))  in __kernel_read()
518 		return warn_unsupported(file, "read");  in __kernel_read()
520 	init_sync_kiocb(&kiocb, file);  in __kernel_read()
523 	ret = file->f_op->read_iter(&kiocb, &iter);  in __kernel_read()
527 		fsnotify_access(file);  in __kernel_read()
534 ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)  in kernel_read()  argument
538 	ret = rw_verify_area(READ, file, pos, count);  in kernel_read()
541 	return __kernel_read(file, buf, count, pos);  in kernel_read()
545 ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)  in vfs_read()  argument
549 	if (!(file->f_mode & FMODE_READ))  in vfs_read()
551 	if (!(file->f_mode & FMODE_CAN_READ))  in vfs_read()
556 	ret = rw_verify_area(READ, file, pos, count);  in vfs_read()
562 	if (file->f_op->read)  in vfs_read()
563 		ret = file->f_op->read(file, buf, count, pos);  in vfs_read()
564 	else if (file->f_op->read_iter)  in vfs_read()
565 		ret = new_sync_read(file, buf, count, pos);  in vfs_read()
569 		fsnotify_access(file);  in vfs_read()
576 static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)  in new_sync_write()
594 ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos)  in __kernel_write_iter()  argument
599 	if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE)))  in __kernel_write_iter()
601 	if (!(file->f_mode & FMODE_CAN_WRITE))  in __kernel_write_iter()
607 	if (unlikely(!file->f_op->write_iter || file->f_op->write))  in __kernel_write_iter()
608 		return warn_unsupported(file, "write");  in __kernel_write_iter()
610 	init_sync_kiocb(&kiocb, file);  in __kernel_write_iter()
612 	ret = file->f_op->write_iter(&kiocb, from);  in __kernel_write_iter()
616 		fsnotify_modify(file);  in __kernel_write_iter()
624 ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)  in __kernel_write()  argument
632 	return __kernel_write_iter(file, &iter, pos);  in __kernel_write()
643 ssize_t kernel_write(struct file *file, const void *buf, size_t count,  in kernel_write()  argument
648 	ret = rw_verify_area(WRITE, file, pos, count);  in kernel_write()
652 	file_start_write(file);  in kernel_write()
653 	ret =  __kernel_write(file, buf, count, pos);  in kernel_write()
654 	file_end_write(file);  in kernel_write()
659 ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)  in vfs_write()  argument
663 	if (!(file->f_mode & FMODE_WRITE))  in vfs_write()
665 	if (!(file->f_mode & FMODE_CAN_WRITE))  in vfs_write()
670 	ret = rw_verify_area(WRITE, file, pos, count);  in vfs_write()
675 	file_start_write(file);  in vfs_write()
676 	if (file->f_op->write)  in vfs_write()
677 		ret = file->f_op->write(file, buf, count, pos);  in vfs_write()
678 	else if (file->f_op->write_iter)  in vfs_write()
679 		ret = new_sync_write(file, buf, count, pos);  in vfs_write()
683 		fsnotify_modify(file);  in vfs_write()
687 	file_end_write(file);  in vfs_write()
691 /* file_ppos returns &file->f_pos or NULL if file is stream */
692 static inline loff_t *file_ppos(struct file *file)  in file_ppos()  argument
694 	return file->f_mode & FMODE_STREAM ? NULL : &file->f_pos;  in file_ppos()
805 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,  in do_iter_readv_writev()
827 /* Do it by hand, with file-ops */
828 static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,  in do_loop_readv_writev()
861 ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb,  in vfs_iocb_iter_read()  argument
867 	if (!file->f_op->read_iter)  in vfs_iocb_iter_read()
869 	if (!(file->f_mode & FMODE_READ))  in vfs_iocb_iter_read()
871 	if (!(file->f_mode & FMODE_CAN_READ))  in vfs_iocb_iter_read()
877 	ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len);  in vfs_iocb_iter_read()
881 	ret = file->f_op->read_iter(iocb, iter);  in vfs_iocb_iter_read()
884 		fsnotify_access(file);  in vfs_iocb_iter_read()
889 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,  in vfs_iter_read()  argument
895 	if (!file->f_op->read_iter)  in vfs_iter_read()
897 	if (!(file->f_mode & FMODE_READ))  in vfs_iter_read()
899 	if (!(file->f_mode & FMODE_CAN_READ))  in vfs_iter_read()
905 	ret = rw_verify_area(READ, file, ppos, tot_len);  in vfs_iter_read()
909 	ret = do_iter_readv_writev(file, iter, ppos, READ, flags);  in vfs_iter_read()
912 		fsnotify_access(file);  in vfs_iter_read()
921 ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,  in vfs_iocb_iter_write()  argument
927 	if (!file->f_op->write_iter)  in vfs_iocb_iter_write()
929 	if (!(file->f_mode & FMODE_WRITE))  in vfs_iocb_iter_write()
931 	if (!(file->f_mode & FMODE_CAN_WRITE))  in vfs_iocb_iter_write()
937 	ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len);  in vfs_iocb_iter_write()
942 	ret = file->f_op->write_iter(iocb, iter);  in vfs_iocb_iter_write()
946 		fsnotify_modify(file);  in vfs_iocb_iter_write()
952 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,  in vfs_iter_write()  argument
958 	if (!(file->f_mode & FMODE_WRITE))  in vfs_iter_write()
960 	if (!(file->f_mode & FMODE_CAN_WRITE))  in vfs_iter_write()
962 	if (!file->f_op->write_iter)  in vfs_iter_write()
969 	ret = rw_verify_area(WRITE, file, ppos, tot_len);  in vfs_iter_write()
973 	file_start_write(file);  in vfs_iter_write()
974 	ret = do_iter_readv_writev(file, iter, ppos, WRITE, flags);  in vfs_iter_write()
976 		fsnotify_modify(file);  in vfs_iter_write()
977 	file_end_write(file);  in vfs_iter_write()
983 static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,  in vfs_readv()  argument
992 	if (!(file->f_mode & FMODE_READ))  in vfs_readv()
994 	if (!(file->f_mode & FMODE_CAN_READ))  in vfs_readv()
1006 	ret = rw_verify_area(READ, file, pos, tot_len);  in vfs_readv()
1010 	if (file->f_op->read_iter)  in vfs_readv()
1011 		ret = do_iter_readv_writev(file, &iter, pos, READ, flags);  in vfs_readv()
1013 		ret = do_loop_readv_writev(file, &iter, pos, READ, flags);  in vfs_readv()
1016 		fsnotify_access(file);  in vfs_readv()
1021 static ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,  in vfs_writev()  argument
1030 	if (!(file->f_mode & FMODE_WRITE))  in vfs_writev()
1032 	if (!(file->f_mode & FMODE_CAN_WRITE))  in vfs_writev()
1044 	ret = rw_verify_area(WRITE, file, pos, tot_len);  in vfs_writev()
1048 	file_start_write(file);  in vfs_writev()
1049 	if (file->f_op->write_iter)  in vfs_writev()
1050 		ret = do_iter_readv_writev(file, &iter, pos, WRITE, flags);  in vfs_writev()
1052 		ret = do_loop_readv_writev(file, &iter, pos, WRITE, flags);  in vfs_writev()
1054 		fsnotify_modify(file);  in vfs_writev()
1055 	file_end_write(file);  in vfs_writev()
1306 	 * Get input file, and verify that it is ok..  in do_sendfile()
1327 	 * Get output file, and verify that it is ok..  in do_sendfile()
1353 	 * EAGAIN on a non-blocking file descriptor.  in do_sendfile()
1468  * Performs necessary checks before doing a file copy
1474 static int generic_copy_file_checks(struct file *file_in, loff_t pos_in,  in generic_copy_file_checks()
1475 				    struct file *file_out, loff_t pos_out,  in generic_copy_file_checks()
1490 	 * a file of the wrong filesystem type to filesystem driver can result  in generic_copy_file_checks()
1530 	/* Don't allow overlapped copying within the same file. */  in generic_copy_file_checks()
1541  * copy_file_range() differs from regular file read and write in that it
1545 ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,  in vfs_copy_file_range()
1546 			    struct file *file_out, loff_t pos_out,  in vfs_copy_file_range()
1575 	 * Cloning is supported by more file systems, so we implement copy on  in vfs_copy_file_range()
1617 	 * to splicing from input file, while file_start_write() is held on  in vfs_copy_file_range()
1618 	 * the output file on a different sb.  in vfs_copy_file_range()
1698 int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count)  in generic_write_check_limits()  argument
1700 	struct inode *inode = file->f_mapping->host;  in generic_write_check_limits()
1712 	if (!(file->f_flags & O_LARGEFILE))  in generic_write_check_limits()
1727 	struct file *file = iocb->ki_filp;  in generic_write_checks_count()  local
1728 	struct inode *inode = file->f_mapping->host;  in generic_write_checks_count()
1741 	      (file->f_op->fop_flags & FOP_BUFFER_WASYNC)))  in generic_write_checks_count()
1770  * Performs common checks before doing a file copy/clone
1773 int generic_file_rw_checks(struct file *file_in, struct file *file_out)  in generic_file_rw_checks()