1/*
2 *  file.c
3 *
4 *  Copyright (C) 1995, 1996 by Volker Lendecke
5 *  Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
6 *
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <asm/uaccess.h>
12
13#include <linux/time.h>
14#include <linux/kernel.h>
15#include <linux/errno.h>
16#include <linux/fcntl.h>
17#include <linux/stat.h>
18#include <linux/mm.h>
19#include <linux/vmalloc.h>
20#include <linux/sched.h>
21
22#include "ncp_fs.h"
23
24static int ncp_fsync(struct file *file, loff_t start, loff_t end, int datasync)
25{
26	return filemap_write_and_wait_range(file->f_mapping, start, end);
27}
28
29/*
30 * Open a file with the specified read/write mode.
31 */
32int ncp_make_open(struct inode *inode, int right)
33{
34	int error;
35	int access;
36
37	error = -EINVAL;
38	if (!inode) {
39		pr_err("%s: got NULL inode\n", __func__);
40		goto out;
41	}
42
43	ncp_dbg(1, "opened=%d, volume # %u, dir entry # %u\n",
44		atomic_read(&NCP_FINFO(inode)->opened),
45		NCP_FINFO(inode)->volNumber,
46		NCP_FINFO(inode)->dirEntNum);
47	error = -EACCES;
48	mutex_lock(&NCP_FINFO(inode)->open_mutex);
49	if (!atomic_read(&NCP_FINFO(inode)->opened)) {
50		struct ncp_entry_info finfo;
51		int result;
52
53		/* tries max. rights */
54		finfo.access = O_RDWR;
55		result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
56					inode, NULL, OC_MODE_OPEN,
57					0, AR_READ | AR_WRITE, &finfo);
58		if (!result)
59			goto update;
60		/* RDWR did not succeeded, try readonly or writeonly as requested */
61		switch (right) {
62			case O_RDONLY:
63				finfo.access = O_RDONLY;
64				result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
65					inode, NULL, OC_MODE_OPEN,
66					0, AR_READ, &finfo);
67				break;
68			case O_WRONLY:
69				finfo.access = O_WRONLY;
70				result = ncp_open_create_file_or_subdir(NCP_SERVER(inode),
71					inode, NULL, OC_MODE_OPEN,
72					0, AR_WRITE, &finfo);
73				break;
74		}
75		if (result) {
76			ncp_vdbg("failed, result=%d\n", result);
77			goto out_unlock;
78		}
79		/*
80		 * Update the inode information.
81		 */
82	update:
83		ncp_update_inode(inode, &finfo);
84		atomic_set(&NCP_FINFO(inode)->opened, 1);
85	}
86
87	access = NCP_FINFO(inode)->access;
88	ncp_vdbg("file open, access=%x\n", access);
89	if (access == right || access == O_RDWR) {
90		atomic_inc(&NCP_FINFO(inode)->opened);
91		error = 0;
92	}
93
94out_unlock:
95	mutex_unlock(&NCP_FINFO(inode)->open_mutex);
96out:
97	return error;
98}
99
100static ssize_t
101ncp_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
102{
103	struct file *file = iocb->ki_filp;
104	struct inode *inode = file_inode(file);
105	size_t already_read = 0;
106	off_t pos = iocb->ki_pos;
107	size_t bufsize;
108	int error;
109	void *freepage;
110	size_t freelen;
111
112	ncp_dbg(1, "enter %pD2\n", file);
113
114	if (!iov_iter_count(to))
115		return 0;
116	if (pos > inode->i_sb->s_maxbytes)
117		return 0;
118	iov_iter_truncate(to, inode->i_sb->s_maxbytes - pos);
119
120	error = ncp_make_open(inode, O_RDONLY);
121	if (error) {
122		ncp_dbg(1, "open failed, error=%d\n", error);
123		return error;
124	}
125
126	bufsize = NCP_SERVER(inode)->buffer_size;
127
128	error = -EIO;
129	freelen = ncp_read_bounce_size(bufsize);
130	freepage = vmalloc(freelen);
131	if (!freepage)
132		goto outrel;
133	error = 0;
134	/* First read in as much as possible for each bufsize. */
135	while (iov_iter_count(to)) {
136		int read_this_time;
137		size_t to_read = min_t(size_t,
138				     bufsize - (pos % bufsize),
139				     iov_iter_count(to));
140
141		error = ncp_read_bounce(NCP_SERVER(inode),
142			 	NCP_FINFO(inode)->file_handle,
143				pos, to_read, to, &read_this_time,
144				freepage, freelen);
145		if (error) {
146			error = -EIO;	/* NW errno -> Linux errno */
147			break;
148		}
149		pos += read_this_time;
150		already_read += read_this_time;
151
152		if (read_this_time != to_read)
153			break;
154	}
155	vfree(freepage);
156
157	iocb->ki_pos = pos;
158
159	file_accessed(file);
160
161	ncp_dbg(1, "exit %pD2\n", file);
162outrel:
163	ncp_inode_close(inode);
164	return already_read ? already_read : error;
165}
166
167static ssize_t
168ncp_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
169{
170	struct file *file = iocb->ki_filp;
171	struct inode *inode = file_inode(file);
172	size_t already_written = 0;
173	size_t bufsize;
174	int errno;
175	void *bouncebuffer;
176	off_t pos;
177
178	ncp_dbg(1, "enter %pD2\n", file);
179	errno = generic_write_checks(iocb, from);
180	if (errno <= 0)
181		return errno;
182
183	errno = ncp_make_open(inode, O_WRONLY);
184	if (errno) {
185		ncp_dbg(1, "open failed, error=%d\n", errno);
186		return errno;
187	}
188	bufsize = NCP_SERVER(inode)->buffer_size;
189
190	errno = file_update_time(file);
191	if (errno)
192		goto outrel;
193
194	bouncebuffer = vmalloc(bufsize);
195	if (!bouncebuffer) {
196		errno = -EIO;	/* -ENOMEM */
197		goto outrel;
198	}
199	pos = iocb->ki_pos;
200	while (iov_iter_count(from)) {
201		int written_this_time;
202		size_t to_write = min_t(size_t,
203				      bufsize - (pos % bufsize),
204				      iov_iter_count(from));
205
206		if (copy_from_iter(bouncebuffer, to_write, from) != to_write) {
207			errno = -EFAULT;
208			break;
209		}
210		if (ncp_write_kernel(NCP_SERVER(inode),
211		    NCP_FINFO(inode)->file_handle,
212		    pos, to_write, bouncebuffer, &written_this_time) != 0) {
213			errno = -EIO;
214			break;
215		}
216		pos += written_this_time;
217		already_written += written_this_time;
218
219		if (written_this_time != to_write)
220			break;
221	}
222	vfree(bouncebuffer);
223
224	iocb->ki_pos = pos;
225
226	if (pos > i_size_read(inode)) {
227		mutex_lock(&inode->i_mutex);
228		if (pos > i_size_read(inode))
229			i_size_write(inode, pos);
230		mutex_unlock(&inode->i_mutex);
231	}
232	ncp_dbg(1, "exit %pD2\n", file);
233outrel:
234	ncp_inode_close(inode);
235	return already_written ? already_written : errno;
236}
237
238static int ncp_release(struct inode *inode, struct file *file) {
239	if (ncp_make_closed(inode)) {
240		ncp_dbg(1, "failed to close\n");
241	}
242	return 0;
243}
244
245const struct file_operations ncp_file_operations =
246{
247	.llseek		= generic_file_llseek,
248	.read_iter	= ncp_file_read_iter,
249	.write_iter	= ncp_file_write_iter,
250	.unlocked_ioctl	= ncp_ioctl,
251#ifdef CONFIG_COMPAT
252	.compat_ioctl	= ncp_compat_ioctl,
253#endif
254	.mmap		= ncp_mmap,
255	.release	= ncp_release,
256	.fsync		= ncp_fsync,
257};
258
259const struct inode_operations ncp_file_inode_operations =
260{
261	.setattr	= ncp_notify_change,
262};
263