xref: /openbmc/linux/fs/udf/file.c (revision 34f5c1c5)
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 <asm/uaccess.h>
31 #include <linux/kernel.h>
32 #include <linux/string.h> /* memset */
33 #include <linux/capability.h>
34 #include <linux/errno.h>
35 #include <linux/smp_lock.h>
36 #include <linux/pagemap.h>
37 #include <linux/buffer_head.h>
38 #include <linux/aio.h>
39 #include <linux/smp_lock.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 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
148 {
149 	struct inode *inode = filp->f_dentry->d_inode;
150 	long old_block, new_block;
151 	int result = -EINVAL;
152 
153 	lock_kernel();
154 
155 	if (file_permission(filp, MAY_READ) != 0) {
156 		udf_debug("no permission to access inode %lu\n", inode->i_ino);
157 		result = -EPERM;
158 		goto out;
159 	}
160 
161 	if (!arg) {
162 		udf_debug("invalid argument to udf_ioctl\n");
163 		result = -EINVAL;
164 		goto out;
165 	}
166 
167 	switch (cmd) {
168 	case UDF_GETVOLIDENT:
169 		if (copy_to_user((char __user *)arg,
170 				 UDF_SB(inode->i_sb)->s_volume_ident, 32))
171 			result = -EFAULT;
172 		else
173 			result = 0;
174 		goto out;
175 	case UDF_RELOCATE_BLOCKS:
176 		if (!capable(CAP_SYS_ADMIN)) {
177 			result = -EACCES;
178 			goto out;
179 		}
180 		if (get_user(old_block, (long __user *)arg)) {
181 			result = -EFAULT;
182 			goto out;
183 		}
184 		result = udf_relocate_blocks(inode->i_sb,
185 						old_block, &new_block);
186 		if (result == 0)
187 			result = put_user(new_block, (long __user *)arg);
188 		goto out;
189 	case UDF_GETEASIZE:
190 		result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
191 		goto out;
192 	case UDF_GETEABLOCK:
193 		result = copy_to_user((char __user *)arg,
194 				      UDF_I(inode)->i_ext.i_data,
195 				      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
196 		goto out;
197 	}
198 
199 out:
200 	unlock_kernel();
201 	return result;
202 }
203 
204 static int udf_release_file(struct inode *inode, struct file *filp)
205 {
206 	if (filp->f_mode & FMODE_WRITE) {
207 		mutex_lock(&inode->i_mutex);
208 		lock_kernel();
209 		udf_discard_prealloc(inode);
210 		udf_truncate_tail_extent(inode);
211 		unlock_kernel();
212 		mutex_unlock(&inode->i_mutex);
213 	}
214 	return 0;
215 }
216 
217 const struct file_operations udf_file_operations = {
218 	.read			= do_sync_read,
219 	.aio_read		= generic_file_aio_read,
220 	.unlocked_ioctl		= udf_ioctl,
221 	.open			= generic_file_open,
222 	.mmap			= generic_file_mmap,
223 	.write			= do_sync_write,
224 	.aio_write		= udf_file_aio_write,
225 	.release		= udf_release_file,
226 	.fsync			= generic_file_fsync,
227 	.splice_read		= generic_file_splice_read,
228 	.llseek			= generic_file_llseek,
229 };
230 
231 const struct inode_operations udf_file_inode_operations = {
232 	.truncate		= udf_truncate,
233 };
234