xref: /linux/fs/reiserfs/ioctl.c (revision 4e1746656839ab1e88d76eec4d2fa0b41d585604)
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/mount.h>
8 #include "reiserfs.h"
9 #include <linux/time.h>
10 #include <linux/uaccess.h>
11 #include <linux/pagemap.h>
12 #include <linux/compat.h>
13 #include <linux/fileattr.h>
14 
15 int reiserfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
16 {
17 	struct inode *inode = d_inode(dentry);
18 
19 	if (!reiserfs_attrs(inode->i_sb))
20 		return -ENOTTY;
21 
22 	fileattr_fill_flags(fa, REISERFS_I(inode)->i_attrs);
23 
24 	return 0;
25 }
26 
27 int reiserfs_fileattr_set(struct mnt_idmap *idmap,
28 			  struct dentry *dentry, struct fileattr *fa)
29 {
30 	struct inode *inode = d_inode(dentry);
31 	unsigned int flags = fa->flags;
32 	int err;
33 
34 	reiserfs_write_lock(inode->i_sb);
35 
36 	err = -ENOTTY;
37 	if (!reiserfs_attrs(inode->i_sb))
38 		goto unlock;
39 
40 	err = -EOPNOTSUPP;
41 	if (fileattr_has_fsx(fa))
42 		goto unlock;
43 
44 	/*
45 	 * Is it quota file? Do not allow user to mess with it
46 	 */
47 	err = -EPERM;
48 	if (IS_NOQUOTA(inode))
49 		goto unlock;
50 
51 	if ((flags & REISERFS_NOTAIL_FL) && S_ISREG(inode->i_mode)) {
52 		err = reiserfs_unpack(inode);
53 		if (err)
54 			goto unlock;
55 	}
56 	sd_attrs_to_i_attrs(flags, inode);
57 	REISERFS_I(inode)->i_attrs = flags;
58 	inode->i_ctime = current_time(inode);
59 	mark_inode_dirty(inode);
60 	err = 0;
61 unlock:
62 	reiserfs_write_unlock(inode->i_sb);
63 
64 	return err;
65 }
66 
67 /*
68  * reiserfs_ioctl - handler for ioctl for inode
69  * supported commands:
70  *  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
71  *                           and prevent packing file (argument arg has t
72  *			      be non-zero)
73  *  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
74  *  3) That's all for a while ...
75  */
76 long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
77 {
78 	struct inode *inode = file_inode(filp);
79 	int err = 0;
80 
81 	reiserfs_write_lock(inode->i_sb);
82 
83 	switch (cmd) {
84 	case REISERFS_IOC_UNPACK:
85 		if (S_ISREG(inode->i_mode)) {
86 			if (arg)
87 				err = reiserfs_unpack(inode);
88 		} else
89 			err = -ENOTTY;
90 		break;
91 		/*
92 		 * following two cases are taken from fs/ext2/ioctl.c by Remy
93 		 * Card (card@masi.ibp.fr)
94 		 */
95 	case REISERFS_IOC_GETVERSION:
96 		err = put_user(inode->i_generation, (int __user *)arg);
97 		break;
98 	case REISERFS_IOC_SETVERSION:
99 		if (!inode_owner_or_capable(&nop_mnt_idmap, inode)) {
100 			err = -EPERM;
101 			break;
102 		}
103 		err = mnt_want_write_file(filp);
104 		if (err)
105 			break;
106 		if (get_user(inode->i_generation, (int __user *)arg)) {
107 			err = -EFAULT;
108 			goto setversion_out;
109 		}
110 		inode->i_ctime = current_time(inode);
111 		mark_inode_dirty(inode);
112 setversion_out:
113 		mnt_drop_write_file(filp);
114 		break;
115 	default:
116 		err = -ENOTTY;
117 	}
118 
119 	reiserfs_write_unlock(inode->i_sb);
120 
121 	return err;
122 }
123 
124 #ifdef CONFIG_COMPAT
125 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
126 				unsigned long arg)
127 {
128 	/*
129 	 * These are just misnamed, they actually
130 	 * get/put from/to user an int
131 	 */
132 	switch (cmd) {
133 	case REISERFS_IOC32_UNPACK:
134 		cmd = REISERFS_IOC_UNPACK;
135 		break;
136 	case REISERFS_IOC32_GETVERSION:
137 		cmd = REISERFS_IOC_GETVERSION;
138 		break;
139 	case REISERFS_IOC32_SETVERSION:
140 		cmd = REISERFS_IOC_SETVERSION;
141 		break;
142 	default:
143 		return -ENOIOCTLCMD;
144 	}
145 
146 	return reiserfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
147 }
148 #endif
149 
150 int reiserfs_commit_write(struct file *f, struct page *page,
151 			  unsigned from, unsigned to);
152 /*
153  * reiserfs_unpack
154  * Function try to convert tail from direct item into indirect.
155  * It set up nopack attribute in the REISERFS_I(inode)->nopack
156  */
157 int reiserfs_unpack(struct inode *inode)
158 {
159 	int retval = 0;
160 	int index;
161 	struct page *page;
162 	struct address_space *mapping;
163 	unsigned long write_from;
164 	unsigned long blocksize = inode->i_sb->s_blocksize;
165 
166 	if (inode->i_size == 0) {
167 		REISERFS_I(inode)->i_flags |= i_nopack_mask;
168 		return 0;
169 	}
170 	/* ioctl already done */
171 	if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
172 		return 0;
173 	}
174 
175 	/* we need to make sure nobody is changing the file size beneath us */
176 	{
177 		int depth = reiserfs_write_unlock_nested(inode->i_sb);
178 
179 		inode_lock(inode);
180 		reiserfs_write_lock_nested(inode->i_sb, depth);
181 	}
182 
183 	reiserfs_write_lock(inode->i_sb);
184 
185 	write_from = inode->i_size & (blocksize - 1);
186 	/* if we are on a block boundary, we are already unpacked.  */
187 	if (write_from == 0) {
188 		REISERFS_I(inode)->i_flags |= i_nopack_mask;
189 		goto out;
190 	}
191 
192 	/*
193 	 * we unpack by finding the page with the tail, and calling
194 	 * __reiserfs_write_begin on that page.  This will force a
195 	 * reiserfs_get_block to unpack the tail for us.
196 	 */
197 	index = inode->i_size >> PAGE_SHIFT;
198 	mapping = inode->i_mapping;
199 	page = grab_cache_page(mapping, index);
200 	retval = -ENOMEM;
201 	if (!page) {
202 		goto out;
203 	}
204 	retval = __reiserfs_write_begin(page, write_from, 0);
205 	if (retval)
206 		goto out_unlock;
207 
208 	/* conversion can change page contents, must flush */
209 	flush_dcache_page(page);
210 	retval = reiserfs_commit_write(NULL, page, write_from, write_from);
211 	REISERFS_I(inode)->i_flags |= i_nopack_mask;
212 
213 out_unlock:
214 	unlock_page(page);
215 	put_page(page);
216 
217 out:
218 	inode_unlock(inode);
219 	reiserfs_write_unlock(inode->i_sb);
220 	return retval;
221 }
222