1/*
2 * file.c
3 *
4 * PURPOSE
5 *  File handling routines for the OSTA-UDF(tm) filesystem.
6 *
7 * CONTACTS
8 *  E-mail regarding any portion of the Linux UDF file system should be
9 *  directed to the development team mailing list (run by majordomo):
10 *    linux_udf@hpesjro.fc.hp.com
11 *
12 * COPYRIGHT
13 *  This file is distributed under the terms of the GNU General Public
14 *  License (GPL). Copies of the GPL can be obtained from:
15 *    ftp://prep.ai.mit.edu/pub/gnu/GPL
16 *  Each contributing author retains all rights to their own work.
17 *
18 *  (C) 1998-1999 Dave Boynton
19 *  (C) 1998-2001 Ben Fennema
20 *  (C) 1999-2000 Stelias Computing Inc
21 *
22 * HISTORY
23 *
24 *  10/02/98 dgb  Attempt to integrate into udf.o
25 *  10/07/98      Switched to using generic_readpage, etc., like isofs
26 *                And it works!
27 *  12/06/98 blf  Added udf_file_read. uses generic_file_read for all cases but
28 *                ICBTAG_FLAG_AD_IN_ICB.
29 *  04/06/99      64 bit file handling on 32 bit systems taken from ext2 file.c
30 *  05/12/99      Preliminary file write support
31 */
32
33#include "udfdecl.h"
34#include <linux/fs.h>
35#include <linux/udf_fs.h>
36#include <asm/uaccess.h>
37#include <linux/kernel.h>
38#include <linux/string.h> /* memset */
39#include <linux/errno.h>
40#include <linux/locks.h>
41#include <linux/smp_lock.h>
42
43#include "udf_i.h"
44#include "udf_sb.h"
45
46static int udf_adinicb_readpage(struct file *file, struct page * page)
47{
48	struct inode *inode = page->mapping->host;
49
50	struct buffer_head *bh;
51	int block;
52	char *kaddr;
53	int err = 0;
54
55	if (!PageLocked(page))
56		PAGE_BUG(page);
57
58	kaddr = kmap(page);
59	memset(kaddr, 0, PAGE_CACHE_SIZE);
60	block = udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0);
61	bh = sb_bread(inode->i_sb, block);
62	if (!bh)
63	{
64		SetPageError(page);
65		err = -EIO;
66		goto out;
67	}
68	memcpy(kaddr, bh->b_data + udf_ext0_offset(inode), inode->i_size);
69	brelse(bh);
70	flush_dcache_page(page);
71	SetPageUptodate(page);
72out:
73	kunmap(page);
74	UnlockPage(page);
75	return err;
76}
77
78static int udf_adinicb_writepage(struct page *page)
79{
80	struct inode *inode = page->mapping->host;
81
82	struct buffer_head *bh;
83	int block;
84	char *kaddr;
85	int err = 0;
86
87	if (!PageLocked(page))
88		PAGE_BUG(page);
89
90	kaddr = kmap(page);
91	block = udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0);
92	bh = sb_bread(inode->i_sb, block);
93	if (!bh)
94	{
95		SetPageError(page);
96		err = -EIO;
97		goto out;
98	}
99	memcpy(bh->b_data + udf_ext0_offset(inode), kaddr, inode->i_size);
100	mark_buffer_dirty(bh);
101	brelse(bh);
102	SetPageUptodate(page);
103out:
104	kunmap(page);
105	UnlockPage(page);
106	return err;
107}
108
109static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
110{
111	kmap(page);
112	return 0;
113}
114
115static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
116{
117	struct inode *inode = page->mapping->host;
118
119	struct buffer_head *bh;
120	int block;
121	char *kaddr = page_address(page);
122	int err = 0;
123
124	block = udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0);
125	bh = sb_bread(inode->i_sb, block);
126	if (!bh)
127	{
128		SetPageError(page);
129		err = -EIO;
130		goto out;
131	}
132	memcpy(bh->b_data + udf_file_entry_alloc_offset(inode) + offset,
133		kaddr + offset, to - offset);
134	mark_buffer_dirty(bh);
135	brelse(bh);
136	SetPageUptodate(page);
137out:
138	kunmap(page);
139	/* only one page here */
140	if (to > inode->i_size)
141		inode->i_size = to;
142	return err;
143}
144
145struct address_space_operations udf_adinicb_aops = {
146	readpage:		udf_adinicb_readpage,
147	writepage:		udf_adinicb_writepage,
148	sync_page:		block_sync_page,
149	prepare_write:		udf_adinicb_prepare_write,
150	commit_write:		udf_adinicb_commit_write,
151};
152
153static ssize_t udf_file_write(struct file * file, const char * buf,
154	size_t count, loff_t *ppos)
155{
156	ssize_t retval;
157	struct inode *inode = file->f_dentry->d_inode;
158	int err, pos;
159
160	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
161	{
162		if (file->f_flags & O_APPEND)
163			pos = inode->i_size;
164		else
165			pos = *ppos;
166
167		if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
168			pos + count))
169		{
170			udf_expand_file_adinicb(inode, pos + count, &err);
171			if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
172			{
173				udf_debug("udf_expand_adinicb: err=%d\n", err);
174				return err;
175			}
176		}
177		else
178		{
179			if (pos + count > inode->i_size)
180				UDF_I_LENALLOC(inode) = pos + count;
181			else
182				UDF_I_LENALLOC(inode) = inode->i_size;
183		}
184	}
185
186	retval = generic_file_write(file, buf, count, ppos);
187
188	if (retval > 0)
189	{
190		UDF_I_UCTIME(inode) = UDF_I_UMTIME(inode) = CURRENT_UTIME;
191		mark_inode_dirty(inode);
192	}
193	return retval;
194}
195
196/*
197 * udf_ioctl
198 *
199 * PURPOSE
200 *	Issue an ioctl.
201 *
202 * DESCRIPTION
203 *	Optional - sys_ioctl() will return -ENOTTY if this routine is not
204 *	available, and the ioctl cannot be handled without filesystem help.
205 *
206 *	sys_ioctl() handles these ioctls that apply only to regular files:
207 *		FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
208 *	These ioctls are also handled by sys_ioctl():
209 *		FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
210 *	All other ioctls are passed to the filesystem.
211 *
212 *	Refer to sys_ioctl() in fs/ioctl.c
213 *	sys_ioctl() -> .
214 *
215 * PRE-CONDITIONS
216 *	inode			Pointer to inode that ioctl was issued on.
217 *	filp			Pointer to file that ioctl was issued on.
218 *	cmd			The ioctl command.
219 *	arg			The ioctl argument [can be interpreted as a
220 *				user-space pointer if desired].
221 *
222 * POST-CONDITIONS
223 *	<return>		Success (>=0) or an error code (<=0) that
224 *				sys_ioctl() will return.
225 *
226 * HISTORY
227 *	July 1, 1997 - Andrew E. Mileski
228 *	Written, tested, and released.
229 */
230int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
231	unsigned long arg)
232{
233	int result = -EINVAL;
234	struct buffer_head *bh = NULL;
235	long_ad eaicb;
236	uint8_t *ea = NULL;
237
238	if ( permission(inode, MAY_READ) != 0 )
239	{
240		udf_debug("no permission to access inode %lu\n",
241						inode->i_ino);
242		return -EPERM;
243	}
244
245	if ( !arg )
246	{
247		udf_debug("invalid argument to udf_ioctl\n");
248		return -EINVAL;
249	}
250
251	/* first, do ioctls that don't need to udf_read */
252	switch (cmd)
253	{
254		case UDF_GETVOLIDENT:
255			return copy_to_user((char *)arg,
256				UDF_SB_VOLIDENT(inode->i_sb), 32) ? -EFAULT : 0;
257		case UDF_RELOCATE_BLOCKS:
258		{
259			long old, new;
260
261			if (!capable(CAP_SYS_ADMIN)) return -EACCES;
262			if (get_user(old, (long *)arg)) return -EFAULT;
263			if ((result = udf_relocate_blocks(inode->i_sb,
264					old, &new)) == 0)
265				result = put_user(new, (long *)arg);
266
267			return result;
268		}
269	}
270
271	/* ok, we need to read the inode */
272	bh = udf_tread(inode->i_sb,
273		udf_get_lb_pblock(inode->i_sb, UDF_I_LOCATION(inode), 0));
274
275	if (!bh)
276	{
277		udf_debug("bread failed (inode=%ld)\n", inode->i_ino);
278		return -EIO;
279	}
280
281	if (UDF_I_EXTENDED_FE(inode) == 0)
282	{
283		struct fileEntry *fe;
284
285		fe = (struct fileEntry *)bh->b_data;
286		eaicb = lela_to_cpu(fe->extendedAttrICB);
287		if (UDF_I_LENEATTR(inode))
288			ea = fe->extendedAttr;
289	}
290	else
291	{
292		struct extendedFileEntry *efe;
293
294		efe = (struct extendedFileEntry *)bh->b_data;
295		eaicb = lela_to_cpu(efe->extendedAttrICB);
296		if (UDF_I_LENEATTR(inode))
297			ea = efe->extendedAttr;
298	}
299
300	switch (cmd)
301	{
302		case UDF_GETEASIZE:
303			result = put_user(UDF_I_LENEATTR(inode), (int *)arg);
304			break;
305
306		case UDF_GETEABLOCK:
307			result = copy_to_user((char *)arg, ea,
308				UDF_I_LENEATTR(inode)) ? -EFAULT : 0;
309			break;
310	}
311
312	udf_release_data(bh);
313	return result;
314}
315
316/*
317 * udf_release_file
318 *
319 * PURPOSE
320 *  Called when all references to the file are closed
321 *
322 * DESCRIPTION
323 *  Discard prealloced blocks
324 *
325 * HISTORY
326 *
327 */
328static int udf_release_file(struct inode * inode, struct file * filp)
329{
330	if (filp->f_mode & FMODE_WRITE)
331	{
332		lock_kernel();
333		udf_discard_prealloc(inode);
334		unlock_kernel();
335	}
336	return 0;
337}
338
339/*
340 * udf_open_file
341 *
342 * PURPOSE
343 *  Called when an inode is about to be open.
344 *
345 * DESCRIPTION
346 *  Use this to disallow opening RW large files on 32 bit systems.
347 *  On 64 bit systems we force on O_LARGEFILE in sys_open.
348 *
349 * HISTORY
350 *
351 */
352static int udf_open_file(struct inode * inode, struct file * filp)
353{
354	if ((inode->i_size & 0xFFFFFFFF80000000ULL) && !(filp->f_flags & O_LARGEFILE))
355		return -EFBIG;
356	return 0;
357}
358
359struct file_operations udf_file_operations = {
360	read:			generic_file_read,
361	ioctl:			udf_ioctl,
362	open:			udf_open_file,
363	mmap:			generic_file_mmap,
364	write:			udf_file_write,
365	release:		udf_release_file,
366	fsync:			udf_fsync_file,
367};
368
369struct inode_operations udf_file_inode_operations = {
370	truncate:		udf_truncate,
371};
372