Root/fs/udf/file.c

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/pagemap.h>
36#include <linux/buffer_head.h>
37#include <linux/aio.h>
38
39#include "udf_i.h"
40#include "udf_sb.h"
41
42static int udf_adinicb_readpage(struct file *file, struct page *page)
43{
44    struct inode *inode = page->mapping->host;
45    char *kaddr;
46    struct udf_inode_info *iinfo = UDF_I(inode);
47
48    BUG_ON(!PageLocked(page));
49
50    kaddr = kmap(page);
51    memset(kaddr, 0, PAGE_CACHE_SIZE);
52    memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
53    flush_dcache_page(page);
54    SetPageUptodate(page);
55    kunmap(page);
56    unlock_page(page);
57
58    return 0;
59}
60
61static int udf_adinicb_writepage(struct page *page,
62                 struct writeback_control *wbc)
63{
64    struct inode *inode = page->mapping->host;
65    char *kaddr;
66    struct udf_inode_info *iinfo = UDF_I(inode);
67
68    BUG_ON(!PageLocked(page));
69
70    kaddr = kmap(page);
71    memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
72    mark_inode_dirty(inode);
73    SetPageUptodate(page);
74    kunmap(page);
75    unlock_page(page);
76
77    return 0;
78}
79
80static int udf_adinicb_write_end(struct file *file,
81            struct address_space *mapping,
82            loff_t pos, unsigned len, unsigned copied,
83            struct page *page, void *fsdata)
84{
85    struct inode *inode = mapping->host;
86    unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
87    char *kaddr;
88    struct udf_inode_info *iinfo = UDF_I(inode);
89
90    kaddr = kmap_atomic(page, KM_USER0);
91    memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
92        kaddr + offset, copied);
93    kunmap_atomic(kaddr, KM_USER0);
94
95    return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
96}
97
98const struct address_space_operations udf_adinicb_aops = {
99    .readpage = udf_adinicb_readpage,
100    .writepage = udf_adinicb_writepage,
101    .write_begin = simple_write_begin,
102    .write_end = udf_adinicb_write_end,
103};
104
105static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
106                  unsigned long nr_segs, loff_t ppos)
107{
108    ssize_t retval;
109    struct file *file = iocb->ki_filp;
110    struct inode *inode = file->f_path.dentry->d_inode;
111    int err, pos;
112    size_t count = iocb->ki_left;
113    struct udf_inode_info *iinfo = UDF_I(inode);
114
115    down_write(&iinfo->i_data_sem);
116    if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
117        if (file->f_flags & O_APPEND)
118            pos = inode->i_size;
119        else
120            pos = ppos;
121
122        if (inode->i_sb->s_blocksize <
123                (udf_file_entry_alloc_offset(inode) +
124                        pos + count)) {
125            err = udf_expand_file_adinicb(inode);
126            if (err) {
127                udf_debug("udf_expand_adinicb: err=%d\n", err);
128                up_write(&iinfo->i_data_sem);
129                return err;
130            }
131        } else {
132            if (pos + count > inode->i_size)
133                iinfo->i_lenAlloc = pos + count;
134            else
135                iinfo->i_lenAlloc = inode->i_size;
136        }
137    }
138    up_write(&iinfo->i_data_sem);
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
147long 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    if (file_permission(filp, MAY_READ) != 0) {
154        udf_debug("no permission to access inode %lu\n", inode->i_ino);
155        result = -EPERM;
156        goto out;
157    }
158
159    if (!arg) {
160        udf_debug("invalid argument to udf_ioctl\n");
161        result = -EINVAL;
162        goto out;
163    }
164
165    switch (cmd) {
166    case UDF_GETVOLIDENT:
167        if (copy_to_user((char __user *)arg,
168                 UDF_SB(inode->i_sb)->s_volume_ident, 32))
169            result = -EFAULT;
170        else
171            result = 0;
172        goto out;
173    case UDF_RELOCATE_BLOCKS:
174        if (!capable(CAP_SYS_ADMIN)) {
175            result = -EACCES;
176            goto out;
177        }
178        if (get_user(old_block, (long __user *)arg)) {
179            result = -EFAULT;
180            goto out;
181        }
182        result = udf_relocate_blocks(inode->i_sb,
183                        old_block, &new_block);
184        if (result == 0)
185            result = put_user(new_block, (long __user *)arg);
186        goto out;
187    case UDF_GETEASIZE:
188        result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
189        goto out;
190    case UDF_GETEABLOCK:
191        result = copy_to_user((char __user *)arg,
192                      UDF_I(inode)->i_ext.i_data,
193                      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
194        goto out;
195    }
196
197out:
198    return result;
199}
200
201static int udf_release_file(struct inode *inode, struct file *filp)
202{
203    if (filp->f_mode & FMODE_WRITE) {
204        mutex_lock(&inode->i_mutex);
205        down_write(&UDF_I(inode)->i_data_sem);
206        udf_discard_prealloc(inode);
207        udf_truncate_tail_extent(inode);
208        up_write(&UDF_I(inode)->i_data_sem);
209        mutex_unlock(&inode->i_mutex);
210    }
211    return 0;
212}
213
214const struct file_operations udf_file_operations = {
215    .read = do_sync_read,
216    .aio_read = generic_file_aio_read,
217    .unlocked_ioctl = udf_ioctl,
218    .open = generic_file_open,
219    .mmap = generic_file_mmap,
220    .write = do_sync_write,
221    .aio_write = udf_file_aio_write,
222    .release = udf_release_file,
223    .fsync = generic_file_fsync,
224    .splice_read = generic_file_splice_read,
225    .llseek = generic_file_llseek,
226};
227
228static int udf_setattr(struct dentry *dentry, struct iattr *attr)
229{
230    struct inode *inode = dentry->d_inode;
231    int error;
232
233    error = inode_change_ok(inode, attr);
234    if (error)
235        return error;
236
237    if ((attr->ia_valid & ATTR_SIZE) &&
238        attr->ia_size != i_size_read(inode)) {
239        error = udf_setsize(inode, attr->ia_size);
240        if (error)
241            return error;
242    }
243
244    setattr_copy(inode, attr);
245    mark_inode_dirty(inode);
246    return 0;
247}
248
249const struct inode_operations udf_file_inode_operations = {
250    .setattr = udf_setattr,
251};
252

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