xref: /openbmc/linux/fs/udf/file.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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) 1998-2004 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/smp_lock.h>
41 #include <linux/pagemap.h>
42 #include <linux/buffer_head.h>
43 
44 #include "udf_i.h"
45 #include "udf_sb.h"
46 
47 static int udf_adinicb_readpage(struct file *file, struct page * page)
48 {
49 	struct inode *inode = page->mapping->host;
50 	char *kaddr;
51 
52 	BUG_ON(!PageLocked(page));
53 
54 	kaddr = kmap(page);
55 	memset(kaddr, 0, PAGE_CACHE_SIZE);
56 	memcpy(kaddr, UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), inode->i_size);
57 	flush_dcache_page(page);
58 	SetPageUptodate(page);
59 	kunmap(page);
60 	unlock_page(page);
61 	return 0;
62 }
63 
64 static int udf_adinicb_writepage(struct page *page, struct writeback_control *wbc)
65 {
66 	struct inode *inode = page->mapping->host;
67 	char *kaddr;
68 
69 	BUG_ON(!PageLocked(page));
70 
71 	kaddr = kmap(page);
72 	memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), kaddr, inode->i_size);
73 	mark_inode_dirty(inode);
74 	SetPageUptodate(page);
75 	kunmap(page);
76 	unlock_page(page);
77 	return 0;
78 }
79 
80 static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
81 {
82 	kmap(page);
83 	return 0;
84 }
85 
86 static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
87 {
88 	struct inode *inode = page->mapping->host;
89 	char *kaddr = page_address(page);
90 
91 	memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,
92 		kaddr + offset, to - offset);
93 	mark_inode_dirty(inode);
94 	SetPageUptodate(page);
95 	kunmap(page);
96 	/* only one page here */
97 	if (to > inode->i_size)
98 		inode->i_size = to;
99 	return 0;
100 }
101 
102 struct address_space_operations udf_adinicb_aops = {
103 	.readpage		= udf_adinicb_readpage,
104 	.writepage		= udf_adinicb_writepage,
105 	.sync_page		= block_sync_page,
106 	.prepare_write		= udf_adinicb_prepare_write,
107 	.commit_write		= udf_adinicb_commit_write,
108 };
109 
110 static ssize_t udf_file_write(struct file * file, const char __user * buf,
111 	size_t count, loff_t *ppos)
112 {
113 	ssize_t retval;
114 	struct inode *inode = file->f_dentry->d_inode;
115 	int err, pos;
116 
117 	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
118 	{
119 		if (file->f_flags & O_APPEND)
120 			pos = inode->i_size;
121 		else
122 			pos = *ppos;
123 
124 		if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
125 			pos + count))
126 		{
127 			udf_expand_file_adinicb(inode, pos + count, &err);
128 			if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
129 			{
130 				udf_debug("udf_expand_adinicb: err=%d\n", err);
131 				return err;
132 			}
133 		}
134 		else
135 		{
136 			if (pos + count > inode->i_size)
137 				UDF_I_LENALLOC(inode) = pos + count;
138 			else
139 				UDF_I_LENALLOC(inode) = inode->i_size;
140 		}
141 	}
142 
143 	retval = generic_file_write(file, buf, count, ppos);
144 
145 	if (retval > 0)
146 		mark_inode_dirty(inode);
147 	return retval;
148 }
149 
150 /*
151  * udf_ioctl
152  *
153  * PURPOSE
154  *	Issue an ioctl.
155  *
156  * DESCRIPTION
157  *	Optional - sys_ioctl() will return -ENOTTY if this routine is not
158  *	available, and the ioctl cannot be handled without filesystem help.
159  *
160  *	sys_ioctl() handles these ioctls that apply only to regular files:
161  *		FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
162  *	These ioctls are also handled by sys_ioctl():
163  *		FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
164  *	All other ioctls are passed to the filesystem.
165  *
166  *	Refer to sys_ioctl() in fs/ioctl.c
167  *	sys_ioctl() -> .
168  *
169  * PRE-CONDITIONS
170  *	inode			Pointer to inode that ioctl was issued on.
171  *	filp			Pointer to file that ioctl was issued on.
172  *	cmd			The ioctl command.
173  *	arg			The ioctl argument [can be interpreted as a
174  *				user-space pointer if desired].
175  *
176  * POST-CONDITIONS
177  *	<return>		Success (>=0) or an error code (<=0) that
178  *				sys_ioctl() will return.
179  *
180  * HISTORY
181  *	July 1, 1997 - Andrew E. Mileski
182  *	Written, tested, and released.
183  */
184 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
185 	unsigned long arg)
186 {
187 	int result = -EINVAL;
188 
189 	if ( permission(inode, MAY_READ, NULL) != 0 )
190 	{
191 		udf_debug("no permission to access inode %lu\n",
192 						inode->i_ino);
193 		return -EPERM;
194 	}
195 
196 	if ( !arg )
197 	{
198 		udf_debug("invalid argument to udf_ioctl\n");
199 		return -EINVAL;
200 	}
201 
202 	switch (cmd)
203 	{
204 		case UDF_GETVOLIDENT:
205 			return copy_to_user((char __user *)arg,
206 				UDF_SB_VOLIDENT(inode->i_sb), 32) ? -EFAULT : 0;
207 		case UDF_RELOCATE_BLOCKS:
208 		{
209 			long old, new;
210 
211 			if (!capable(CAP_SYS_ADMIN)) return -EACCES;
212 			if (get_user(old, (long __user *)arg)) return -EFAULT;
213 			if ((result = udf_relocate_blocks(inode->i_sb,
214 					old, &new)) == 0)
215 				result = put_user(new, (long __user *)arg);
216 
217 			return result;
218 		}
219 		case UDF_GETEASIZE:
220 			result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg);
221 			break;
222 
223 		case UDF_GETEABLOCK:
224 			result = copy_to_user((char __user *)arg, UDF_I_DATA(inode),
225 				UDF_I_LENEATTR(inode)) ? -EFAULT : 0;
226 			break;
227 	}
228 
229 	return result;
230 }
231 
232 /*
233  * udf_release_file
234  *
235  * PURPOSE
236  *  Called when all references to the file are closed
237  *
238  * DESCRIPTION
239  *  Discard prealloced blocks
240  *
241  * HISTORY
242  *
243  */
244 static int udf_release_file(struct inode * inode, struct file * filp)
245 {
246 	if (filp->f_mode & FMODE_WRITE)
247 	{
248 		lock_kernel();
249 		udf_discard_prealloc(inode);
250 		unlock_kernel();
251 	}
252 	return 0;
253 }
254 
255 struct file_operations udf_file_operations = {
256 	.read			= generic_file_read,
257 	.ioctl			= udf_ioctl,
258 	.open			= generic_file_open,
259 	.mmap			= generic_file_mmap,
260 	.write			= udf_file_write,
261 	.release		= udf_release_file,
262 	.fsync			= udf_fsync_file,
263 	.sendfile		= generic_file_sendfile,
264 };
265 
266 struct inode_operations udf_file_inode_operations = {
267 	.truncate		= udf_truncate,
268 };
269