1 /*
2 * Copyright 2000-2002 by Hans Reiser, licensing governed by reiserfs/README
3 */
4
5 #include <linux/fs.h>
6 #include <linux/reiserfs_fs.h>
7 #include <linux/sched.h>
8 #include <asm/uaccess.h>
9 #include <linux/smp_lock.h>
10 #include <linux/locks.h>
11
12 /*
13 ** reiserfs_ioctl - handler for ioctl for inode
14 ** supported commands:
15 ** 1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
16 ** and prevent packing file (argument arg has to be non-zero)
17 ** 2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
18 ** 3) That's all for a while ...
19 */
reiserfs_ioctl(struct inode * inode,struct file * filp,unsigned int cmd,unsigned long arg)20 int reiserfs_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
21 unsigned long arg)
22 {
23 unsigned int flags;
24
25 switch (cmd) {
26 case REISERFS_IOC_UNPACK:
27 if( S_ISREG( inode -> i_mode ) ) {
28 if (arg)
29 return reiserfs_unpack (inode, filp);
30 else
31 return 0;
32 } else
33 return -ENOTTY;
34 /*
35 * Following {G,S}ETFLAGS, and {G,S}ETVERSION are providing ext2
36 * binary compatible interface (used by lsattr(1), and chattr(1)) and
37 * are * thus conceptually similar to appropriate pieces of
38 * fs/ext2/ioctl.c
39 */
40 case REISERFS_IOC_GETFLAGS:
41 flags = inode -> u.reiserfs_i.i_attrs;
42 i_attrs_to_sd_attrs( inode, ( __u16 * ) &flags );
43 return put_user(flags, (int *) arg);
44 case REISERFS_IOC_SETFLAGS: {
45 if (IS_RDONLY(inode))
46 return -EROFS;
47
48 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
49 return -EPERM;
50
51 if (get_user(flags, (int *) arg))
52 return -EFAULT;
53
54 if ( ( ( flags ^ inode->u.reiserfs_i.i_attrs) & ( REISERFS_IMMUTABLE_FL | REISERFS_APPEND_FL)) &&
55 !capable( CAP_LINUX_IMMUTABLE ) )
56 return -EPERM;
57
58 if( ( flags & REISERFS_NOTAIL_FL ) &&
59 S_ISREG( inode -> i_mode ) ) {
60 int result;
61
62 result = reiserfs_unpack( inode, filp );
63 if( result )
64 return result;
65 }
66 sd_attrs_to_i_attrs( flags, inode );
67 inode -> u.reiserfs_i.i_attrs = flags;
68 inode->i_ctime = CURRENT_TIME;
69 mark_inode_dirty(inode);
70 return 0;
71 }
72 case REISERFS_IOC_GETVERSION:
73 return put_user(inode->i_generation, (int *) arg);
74 case REISERFS_IOC_SETVERSION:
75 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
76 return -EPERM;
77 if (IS_RDONLY(inode))
78 return -EROFS;
79 if (get_user(inode->i_generation, (int *) arg))
80 return -EFAULT;
81 inode->i_ctime = CURRENT_TIME;
82 mark_inode_dirty(inode);
83 return 0;
84 default:
85 return -ENOTTY;
86 }
87 return 0;
88 }
89
90 /*
91 ** reiserfs_unpack
92 ** Function try to convert tail from direct item into indirect.
93 ** It set up nopack attribute in the inode.u.reiserfs_i.nopack
94 */
reiserfs_unpack(struct inode * inode,struct file * filp)95 int reiserfs_unpack (struct inode * inode, struct file * filp)
96 {
97 int retval = 0;
98 int index ;
99 struct page *page ;
100 unsigned long write_from ;
101 unsigned long blocksize = inode->i_sb->s_blocksize ;
102
103 if (inode->i_size == 0) {
104 inode->u.reiserfs_i.i_flags |= i_nopack_mask;
105 return 0 ;
106 }
107 /* ioctl already done */
108 if (inode->u.reiserfs_i.i_flags & i_nopack_mask) {
109 return 0 ;
110 }
111 lock_kernel();
112
113 /* we need to make sure nobody is changing the file size beneath
114 ** us
115 */
116 down(&inode->i_sem) ;
117
118 write_from = inode->i_size & (blocksize - 1) ;
119 /* if we are on a block boundary, we are already unpacked. */
120 if ( write_from == 0) {
121 inode->u.reiserfs_i.i_flags |= i_nopack_mask;
122 goto out ;
123 }
124
125 /* we unpack by finding the page with the tail, and calling
126 ** reiserfs_prepare_write on that page. This will force a
127 ** reiserfs_get_block to unpack the tail for us.
128 */
129 index = inode->i_size >> PAGE_CACHE_SHIFT ;
130 page = grab_cache_page(inode->i_mapping, index) ;
131 retval = -ENOMEM;
132 if (!page) {
133 goto out ;
134 }
135 retval = reiserfs_prepare_write(NULL, page, write_from, blocksize) ;
136 if (retval)
137 goto out_unlock ;
138
139 /* conversion can change page contents, must flush */
140 flush_dcache_page(page) ;
141 inode->u.reiserfs_i.i_flags |= i_nopack_mask;
142 kunmap(page) ; /* mapped by prepare_write */
143
144 out_unlock:
145 UnlockPage(page) ;
146 page_cache_release(page) ;
147
148 out:
149 up(&inode->i_sem) ;
150 unlock_kernel();
151 return retval;
152 }
153