summaryrefslogtreecommitdiffstats
path: root/target/linux/generic/patches-3.8/441-block2mtd_refresh.patch
blob: 11b743db2ec61c34783840d0680a61f54ee8e5a3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -29,6 +29,8 @@ struct block2mtd_dev {
 	struct block_device *blkdev;
 	struct mtd_info mtd;
 	struct mutex write_mutex;
+	rwlock_t bdev_mutex;
+	char devname[0];
 };
 
 
@@ -80,6 +82,12 @@ static int block2mtd_erase(struct mtd_in
 	size_t len = instr->len;
 	int err;
 
+	read_lock(&dev->bdev_mutex);
+	if (!dev->blkdev) {
+		err = -EINVAL;
+		goto done;
+	}
+
 	instr->state = MTD_ERASING;
 	mutex_lock(&dev->write_mutex);
 	err = _block2mtd_erase(dev, from, len);
@@ -91,6 +99,10 @@ static int block2mtd_erase(struct mtd_in
 		instr->state = MTD_ERASE_DONE;
 
 	mtd_erase_callback(instr);
+
+done:
+	read_unlock(&dev->bdev_mutex);
+
 	return err;
 }
 
@@ -102,7 +114,13 @@ static int block2mtd_read(struct mtd_inf
 	struct page *page;
 	int index = from >> PAGE_SHIFT;
 	int offset = from & (PAGE_SIZE-1);
-	int cpylen;
+	int cpylen, err = 0;
+
+	read_lock(&dev->bdev_mutex);
+	if (!dev->blkdev || (from > mtd->size)) {
+		err = -EINVAL;
+		goto done;
+	}
 
 	while (len) {
 		if ((offset + len) > PAGE_SIZE)
@@ -112,8 +130,10 @@ static int block2mtd_read(struct mtd_inf
 		len = len - cpylen;
 
 		page = page_read(dev->blkdev->bd_inode->i_mapping, index);
-		if (IS_ERR(page))
+		if (IS_ERR(page)) {
 			return PTR_ERR(page);
+			goto done;
+		}
 
 		memcpy(buf, page_address(page) + offset, cpylen);
 		page_cache_release(page);
@@ -124,7 +144,10 @@ static int block2mtd_read(struct mtd_inf
 		offset = 0;
 		index++;
 	}
-	return 0;
+
+done:
+	read_unlock(&dev->bdev_mutex);
+	return err;
 }
 
 
@@ -173,13 +196,22 @@ static int block2mtd_write(struct mtd_in
 		size_t *retlen, const u_char *buf)
 {
 	struct block2mtd_dev *dev = mtd->priv;
-	int err;
+	int err = 0;
+
+	read_lock(&dev->bdev_mutex);
+	if (!dev->blkdev) {
+		err = -EINVAL;
+		goto done;
+	}
 
 	mutex_lock(&dev->write_mutex);
 	err = _block2mtd_write(dev, buf, to, len, retlen);
 	mutex_unlock(&dev->write_mutex);
 	if (err > 0)
 		err = 0;
+
+done:
+	read_unlock(&dev->bdev_mutex);
 	return err;
 }
 
@@ -188,33 +220,110 @@ static int block2mtd_write(struct mtd_in
 static void block2mtd_sync(struct mtd_info *mtd)
 {
 	struct block2mtd_dev *dev = mtd->priv;
+	read_lock(&dev->bdev_mutex);
+	if (dev->blkdev)
 	sync_blockdev(dev->blkdev);
+	read_unlock(&dev->bdev_mutex);
+
 	return;
 }
 
 
+static int _open_bdev(struct block2mtd_dev *dev)
+{
+	const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
+	struct block_device *bdev;
+
+	/* Get a handle on the device */
+	bdev = blkdev_get_by_path(dev->devname, mode, dev);
+#ifndef MODULE
+	if (IS_ERR(bdev)) {
+		dev_t devt;
+
+		/* We might not have rootfs mounted at this point. Try
+		   to resolve the device name by other means. */
+
+		devt = name_to_dev_t(dev->devname);
+		if (devt)
+			bdev = blkdev_get_by_dev(devt, mode, dev);
+	}
+#endif
+
+	if (IS_ERR(bdev)) {
+		ERROR("error: cannot open device %s", dev->devname);
+		return 1;
+	}
+	dev->blkdev = bdev;
+
+	if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
+		ERROR("attempting to use an MTD device as a block device");
+		return 1;
+	}
+
+	return 0;
+}
+
+static void _close_bdev(struct block2mtd_dev *dev)
+{
+	struct block_device *bdev;
+
+	if (!dev->blkdev)
+		return;
+
+	bdev = dev->blkdev;
+	invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
+	blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
+	dev->blkdev = NULL;
+}
+
 static void block2mtd_free_device(struct block2mtd_dev *dev)
 {
 	if (!dev)
 		return;
 
 	kfree(dev->mtd.name);
-
-	if (dev->blkdev) {
-		invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
-					0, -1);
-		blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
-	}
-
+	_close_bdev(dev);
 	kfree(dev);
 }
 
 
-/* FIXME: ensure that mtd->size % erase_size == 0 */
-static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
+static int block2mtd_refresh(struct mtd_info *mtd)
 {
-	const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
+	struct block2mtd_dev *dev = mtd->priv;
 	struct block_device *bdev;
+	dev_t devt;
+	int err = 0;
+
+	/* no other mtd function can run at this point */
+	write_lock(&dev->bdev_mutex);
+
+	/* get the device number for the whole disk */
+	devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
+
+	/* close the old block device */
+	_close_bdev(dev);
+
+	/* open the whole disk, issue a partition rescan, then */
+	bdev = blkdev_get_by_dev(devt, FMODE_WRITE | FMODE_READ, mtd);
+	if (!bdev || !bdev->bd_disk)
+		err = -EINVAL;
+#ifndef CONFIG_MTD_BLOCK2MTD_MODULE
+	else
+		err = rescan_partitions(bdev->bd_disk, bdev);
+#endif
+	if (bdev)
+		blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
+
+	/* try to open the partition block device again */
+	_open_bdev(dev);
+	write_unlock(&dev->bdev_mutex);
+
+	return err;
+}
+
+/* FIXME: ensure that mtd->size % erase_size == 0 */
+static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
+{
 	struct block2mtd_dev *dev;
 	struct mtd_partition *part;
 	char *name;
@@ -222,36 +331,17 @@ static struct block2mtd_dev *add_device(
 	if (!devname)
 		return NULL;
 
-	dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
+	dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
 	if (!dev)
 		return NULL;
 
-	/* Get a handle on the device */
-	bdev = blkdev_get_by_path(devname, mode, dev);
-#ifndef MODULE
-	if (IS_ERR(bdev)) {
+	strcpy(dev->devname, devname);
 
-		/* We might not have rootfs mounted at this point. Try
-		   to resolve the device name by other means. */
-
-		dev_t devt = name_to_dev_t(devname);
-		if (devt)
-			bdev = blkdev_get_by_dev(devt, mode, dev);
-	}
-#endif
-
-	if (IS_ERR(bdev)) {
-		ERROR("error: cannot open device %s", devname);
-		goto devinit_err;
-	}
-	dev->blkdev = bdev;
-
-	if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
-		ERROR("attempting to use an MTD device as a block device");
+	if (_open_bdev(dev))
 		goto devinit_err;
-	}
 
 	mutex_init(&dev->write_mutex);
+	rwlock_init(&dev->bdev_mutex);
 
 	/* Setup the MTD structure */
 	/* make the name contain the block device in */
@@ -276,6 +366,7 @@ static struct block2mtd_dev *add_device(
 	dev->mtd._read = block2mtd_read;
 	dev->mtd.priv = dev;
 	dev->mtd.owner = THIS_MODULE;
+	dev->mtd.refresh_device = block2mtd_refresh;
 
 	part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
 	part->name = name;