Merge git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
[linux-2.6] / fs / reiserfs / ioctl.c
1 /*
2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3  */
4
5 #include <linux/capability.h>
6 #include <linux/fs.h>
7 #include <linux/reiserfs_fs.h>
8 #include <linux/time.h>
9 #include <asm/uaccess.h>
10 #include <linux/pagemap.h>
11 #include <linux/smp_lock.h>
12 #include <linux/compat.h>
13
14 static int reiserfs_unpack(struct inode *inode, struct file *filp);
15
16 /*
17 ** reiserfs_ioctl - handler for ioctl for inode
18 ** supported commands:
19 **  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
20 **                           and prevent packing file (argument arg has to be non-zero)
21 **  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
22 **  3) That's all for a while ...
23 */
24 int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
25                    unsigned long arg)
26 {
27         unsigned int flags;
28
29         switch (cmd) {
30         case REISERFS_IOC_UNPACK:
31                 if (S_ISREG(inode->i_mode)) {
32                         if (arg)
33                                 return reiserfs_unpack(inode, filp);
34                         else
35                                 return 0;
36                 } else
37                         return -ENOTTY;
38                 /* following two cases are taken from fs/ext2/ioctl.c by Remy
39                    Card (card@masi.ibp.fr) */
40         case REISERFS_IOC_GETFLAGS:
41                 if (!reiserfs_attrs(inode->i_sb))
42                         return -ENOTTY;
43
44                 flags = REISERFS_I(inode)->i_attrs;
45                 i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
46                 return put_user(flags, (int __user *)arg);
47         case REISERFS_IOC_SETFLAGS:{
48                         if (!reiserfs_attrs(inode->i_sb))
49                                 return -ENOTTY;
50
51                         if (IS_RDONLY(inode))
52                                 return -EROFS;
53
54                         if (!is_owner_or_cap(inode))
55                                 return -EPERM;
56
57                         if (get_user(flags, (int __user *)arg))
58                                 return -EFAULT;
59
60                         /* Is it quota file? Do not allow user to mess with it. */
61                         if (IS_NOQUOTA(inode))
62                                 return -EPERM;
63                         if (((flags ^ REISERFS_I(inode)->
64                               i_attrs) & (REISERFS_IMMUTABLE_FL |
65                                           REISERFS_APPEND_FL))
66                             && !capable(CAP_LINUX_IMMUTABLE))
67                                 return -EPERM;
68
69                         if ((flags & REISERFS_NOTAIL_FL) &&
70                             S_ISREG(inode->i_mode)) {
71                                 int result;
72
73                                 result = reiserfs_unpack(inode, filp);
74                                 if (result)
75                                         return result;
76                         }
77                         sd_attrs_to_i_attrs(flags, inode);
78                         REISERFS_I(inode)->i_attrs = flags;
79                         inode->i_ctime = CURRENT_TIME_SEC;
80                         mark_inode_dirty(inode);
81                         return 0;
82                 }
83         case REISERFS_IOC_GETVERSION:
84                 return put_user(inode->i_generation, (int __user *)arg);
85         case REISERFS_IOC_SETVERSION:
86                 if (!is_owner_or_cap(inode))
87                         return -EPERM;
88                 if (IS_RDONLY(inode))
89                         return -EROFS;
90                 if (get_user(inode->i_generation, (int __user *)arg))
91                         return -EFAULT;
92                 inode->i_ctime = CURRENT_TIME_SEC;
93                 mark_inode_dirty(inode);
94                 return 0;
95         default:
96                 return -ENOTTY;
97         }
98 }
99
100 #ifdef CONFIG_COMPAT
101 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
102                                 unsigned long arg)
103 {
104         struct inode *inode = file->f_path.dentry->d_inode;
105         int ret;
106
107         /* These are just misnamed, they actually get/put from/to user an int */
108         switch (cmd) {
109         case REISERFS_IOC32_UNPACK:
110                 cmd = REISERFS_IOC_UNPACK;
111                 break;
112         case REISERFS_IOC32_GETFLAGS:
113                 cmd = REISERFS_IOC_GETFLAGS;
114                 break;
115         case REISERFS_IOC32_SETFLAGS:
116                 cmd = REISERFS_IOC_SETFLAGS;
117                 break;
118         case REISERFS_IOC32_GETVERSION:
119                 cmd = REISERFS_IOC_GETVERSION;
120                 break;
121         case REISERFS_IOC32_SETVERSION:
122                 cmd = REISERFS_IOC_SETVERSION;
123                 break;
124         default:
125                 return -ENOIOCTLCMD;
126         }
127         lock_kernel();
128         ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
129         unlock_kernel();
130         return ret;
131 }
132 #endif
133
134 int reiserfs_commit_write(struct file *f, struct page *page,
135                           unsigned from, unsigned to);
136 int reiserfs_prepare_write(struct file *f, struct page *page,
137                            unsigned from, unsigned to);
138 /*
139 ** reiserfs_unpack
140 ** Function try to convert tail from direct item into indirect.
141 ** It set up nopack attribute in the REISERFS_I(inode)->nopack
142 */
143 static int reiserfs_unpack(struct inode *inode, struct file *filp)
144 {
145         int retval = 0;
146         int index;
147         struct page *page;
148         struct address_space *mapping;
149         unsigned long write_from;
150         unsigned long blocksize = inode->i_sb->s_blocksize;
151
152         if (inode->i_size == 0) {
153                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
154                 return 0;
155         }
156         /* ioctl already done */
157         if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
158                 return 0;
159         }
160
161         /* we need to make sure nobody is changing the file size beneath
162          ** us
163          */
164         mutex_lock(&inode->i_mutex);
165         reiserfs_write_lock(inode->i_sb);
166
167         write_from = inode->i_size & (blocksize - 1);
168         /* if we are on a block boundary, we are already unpacked.  */
169         if (write_from == 0) {
170                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
171                 goto out;
172         }
173
174         /* we unpack by finding the page with the tail, and calling
175          ** reiserfs_prepare_write on that page.  This will force a 
176          ** reiserfs_get_block to unpack the tail for us.
177          */
178         index = inode->i_size >> PAGE_CACHE_SHIFT;
179         mapping = inode->i_mapping;
180         page = grab_cache_page(mapping, index);
181         retval = -ENOMEM;
182         if (!page) {
183                 goto out;
184         }
185         retval = reiserfs_prepare_write(NULL, page, write_from, write_from);
186         if (retval)
187                 goto out_unlock;
188
189         /* conversion can change page contents, must flush */
190         flush_dcache_page(page);
191         retval = reiserfs_commit_write(NULL, page, write_from, write_from);
192         REISERFS_I(inode)->i_flags |= i_nopack_mask;
193
194       out_unlock:
195         unlock_page(page);
196         page_cache_release(page);
197
198       out:
199         mutex_unlock(&inode->i_mutex);
200         reiserfs_write_unlock(inode->i_sb);
201         return retval;
202 }