xref: /openbmc/linux/fs/udf/file.c (revision f42b3800)
1 /*
2  * file.c
3  *
4  * PURPOSE
5  *  File handling routines for the OSTA-UDF(tm) filesystem.
6  *
7  * COPYRIGHT
8  *  This file is distributed under the terms of the GNU General Public
9  *  License (GPL). Copies of the GPL can be obtained from:
10  *    ftp://prep.ai.mit.edu/pub/gnu/GPL
11  *  Each contributing author retains all rights to their own work.
12  *
13  *  (C) 1998-1999 Dave Boynton
14  *  (C) 1998-2004 Ben Fennema
15  *  (C) 1999-2000 Stelias Computing Inc
16  *
17  * HISTORY
18  *
19  *  10/02/98 dgb  Attempt to integrate into udf.o
20  *  10/07/98      Switched to using generic_readpage, etc., like isofs
21  *                And it works!
22  *  12/06/98 blf  Added udf_file_read. uses generic_file_read for all cases but
23  *                ICBTAG_FLAG_AD_IN_ICB.
24  *  04/06/99      64 bit file handling on 32 bit systems taken from ext2 file.c
25  *  05/12/99      Preliminary file write support
26  */
27 
28 #include "udfdecl.h"
29 #include <linux/fs.h>
30 #include <linux/udf_fs.h>
31 #include <asm/uaccess.h>
32 #include <linux/kernel.h>
33 #include <linux/string.h> /* memset */
34 #include <linux/capability.h>
35 #include <linux/errno.h>
36 #include <linux/smp_lock.h>
37 #include <linux/pagemap.h>
38 #include <linux/buffer_head.h>
39 #include <linux/aio.h>
40 
41 #include "udf_i.h"
42 #include "udf_sb.h"
43 
44 static int udf_adinicb_readpage(struct file *file, struct page *page)
45 {
46 	struct inode *inode = page->mapping->host;
47 	char *kaddr;
48 	struct udf_inode_info *iinfo = UDF_I(inode);
49 
50 	BUG_ON(!PageLocked(page));
51 
52 	kaddr = kmap(page);
53 	memset(kaddr, 0, PAGE_CACHE_SIZE);
54 	memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
55 	flush_dcache_page(page);
56 	SetPageUptodate(page);
57 	kunmap(page);
58 	unlock_page(page);
59 
60 	return 0;
61 }
62 
63 static int udf_adinicb_writepage(struct page *page,
64 				 struct writeback_control *wbc)
65 {
66 	struct inode *inode = page->mapping->host;
67 	char *kaddr;
68 	struct udf_inode_info *iinfo = UDF_I(inode);
69 
70 	BUG_ON(!PageLocked(page));
71 
72 	kaddr = kmap(page);
73 	memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
74 	mark_inode_dirty(inode);
75 	SetPageUptodate(page);
76 	kunmap(page);
77 	unlock_page(page);
78 
79 	return 0;
80 }
81 
82 static int udf_adinicb_write_end(struct file *file,
83 			struct address_space *mapping,
84 			loff_t pos, unsigned len, unsigned copied,
85 			struct page *page, void *fsdata)
86 {
87 	struct inode *inode = mapping->host;
88 	unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
89 	char *kaddr;
90 	struct udf_inode_info *iinfo = UDF_I(inode);
91 
92 	kaddr = kmap_atomic(page, KM_USER0);
93 	memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
94 		kaddr + offset, copied);
95 	kunmap_atomic(kaddr, KM_USER0);
96 
97 	return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
98 }
99 
100 const struct address_space_operations udf_adinicb_aops = {
101 	.readpage	= udf_adinicb_readpage,
102 	.writepage	= udf_adinicb_writepage,
103 	.sync_page	= block_sync_page,
104 	.write_begin = simple_write_begin,
105 	.write_end = udf_adinicb_write_end,
106 };
107 
108 static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
109 				  unsigned long nr_segs, loff_t ppos)
110 {
111 	ssize_t retval;
112 	struct file *file = iocb->ki_filp;
113 	struct inode *inode = file->f_path.dentry->d_inode;
114 	int err, pos;
115 	size_t count = iocb->ki_left;
116 	struct udf_inode_info *iinfo = UDF_I(inode);
117 
118 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
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 <
125 				(udf_file_entry_alloc_offset(inode) +
126 						pos + count)) {
127 			udf_expand_file_adinicb(inode, pos + count, &err);
128 			if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
129 				udf_debug("udf_expand_adinicb: err=%d\n", err);
130 				return err;
131 			}
132 		} else {
133 			if (pos + count > inode->i_size)
134 				iinfo->i_lenAlloc = pos + count;
135 			else
136 				iinfo->i_lenAlloc = inode->i_size;
137 		}
138 	}
139 
140 	retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
141 	if (retval > 0)
142 		mark_inode_dirty(inode);
143 
144 	return retval;
145 }
146 
147 /*
148  * udf_ioctl
149  *
150  * PURPOSE
151  *	Issue an ioctl.
152  *
153  * DESCRIPTION
154  *	Optional - sys_ioctl() will return -ENOTTY if this routine is not
155  *	available, and the ioctl cannot be handled without filesystem help.
156  *
157  *	sys_ioctl() handles these ioctls that apply only to regular files:
158  *		FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
159  *	These ioctls are also handled by sys_ioctl():
160  *		FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
161  *	All other ioctls are passed to the filesystem.
162  *
163  *	Refer to sys_ioctl() in fs/ioctl.c
164  *	sys_ioctl() -> .
165  *
166  * PRE-CONDITIONS
167  *	inode			Pointer to inode that ioctl was issued on.
168  *	filp			Pointer to file that ioctl was issued on.
169  *	cmd			The ioctl command.
170  *	arg			The ioctl argument [can be interpreted as a
171  *				user-space pointer if desired].
172  *
173  * POST-CONDITIONS
174  *	<return>		Success (>=0) or an error code (<=0) that
175  *				sys_ioctl() will return.
176  *
177  * HISTORY
178  *	July 1, 1997 - Andrew E. Mileski
179  *	Written, tested, and released.
180  */
181 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
182 	      unsigned long arg)
183 {
184 	long old_block, new_block;
185 	int result = -EINVAL;
186 
187 	if (file_permission(filp, MAY_READ) != 0) {
188 		udf_debug("no permission to access inode %lu\n",
189 			  inode->i_ino);
190 		return -EPERM;
191 	}
192 
193 	if (!arg) {
194 		udf_debug("invalid argument to udf_ioctl\n");
195 		return -EINVAL;
196 	}
197 
198 	switch (cmd) {
199 	case UDF_GETVOLIDENT:
200 		if (copy_to_user((char __user *)arg,
201 				 UDF_SB(inode->i_sb)->s_volume_ident, 32))
202 			return -EFAULT;
203 		else
204 			return 0;
205 	case UDF_RELOCATE_BLOCKS:
206 		if (!capable(CAP_SYS_ADMIN))
207 			return -EACCES;
208 		if (get_user(old_block, (long __user *)arg))
209 			return -EFAULT;
210 		result = udf_relocate_blocks(inode->i_sb,
211 						old_block, &new_block);
212 		if (result == 0)
213 			result = put_user(new_block, (long __user *)arg);
214 		return result;
215 	case UDF_GETEASIZE:
216 		result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
217 		break;
218 	case UDF_GETEABLOCK:
219 		result = copy_to_user((char __user *)arg,
220 				      UDF_I(inode)->i_ext.i_data,
221 				      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
222 		break;
223 	}
224 
225 	return result;
226 }
227 
228 /*
229  * udf_release_file
230  *
231  * PURPOSE
232  *  Called when all references to the file are closed
233  *
234  * DESCRIPTION
235  *  Discard prealloced blocks
236  *
237  * HISTORY
238  *
239  */
240 static int udf_release_file(struct inode *inode, struct file *filp)
241 {
242 	if (filp->f_mode & FMODE_WRITE) {
243 		lock_kernel();
244 		udf_discard_prealloc(inode);
245 		unlock_kernel();
246 	}
247 	return 0;
248 }
249 
250 const struct file_operations udf_file_operations = {
251 	.read			= do_sync_read,
252 	.aio_read		= generic_file_aio_read,
253 	.ioctl			= udf_ioctl,
254 	.open			= generic_file_open,
255 	.mmap			= generic_file_mmap,
256 	.write			= do_sync_write,
257 	.aio_write		= udf_file_aio_write,
258 	.release		= udf_release_file,
259 	.fsync			= udf_fsync_file,
260 	.splice_read		= generic_file_splice_read,
261 };
262 
263 const struct inode_operations udf_file_inode_operations = {
264 	.truncate = udf_truncate,
265 };
266