Root/target/linux/generic/patches-2.6.37/441-block2mtd_refresh.patch

1--- a/drivers/mtd/devices/block2mtd.c
2+++ b/drivers/mtd/devices/block2mtd.c
3@@ -30,6 +30,8 @@ struct block2mtd_dev {
4     struct block_device *blkdev;
5     struct mtd_info mtd;
6     struct mutex write_mutex;
7+ rwlock_t bdev_mutex;
8+ char devname[0];
9 };
10 
11 
12@@ -82,6 +84,12 @@ static int block2mtd_erase(struct mtd_in
13     size_t len = instr->len;
14     int err;
15 
16+ read_lock(&dev->bdev_mutex);
17+ if (!dev->blkdev) {
18+ err = -EINVAL;
19+ goto done;
20+ }
21+
22     instr->state = MTD_ERASING;
23     mutex_lock(&dev->write_mutex);
24     err = _block2mtd_erase(dev, from, len);
25@@ -93,6 +101,10 @@ static int block2mtd_erase(struct mtd_in
26         instr->state = MTD_ERASE_DONE;
27 
28     mtd_erase_callback(instr);
29+
30+done:
31+ read_unlock(&dev->bdev_mutex);
32+
33     return err;
34 }
35 
36@@ -104,10 +116,14 @@ static int block2mtd_read(struct mtd_inf
37     struct page *page;
38     int index = from >> PAGE_SHIFT;
39     int offset = from & (PAGE_SIZE-1);
40- int cpylen;
41+ int cpylen, err = 0;
42+
43+ read_lock(&dev->bdev_mutex);
44+ if (!dev->blkdev || (from > mtd->size)) {
45+ err = -EINVAL;
46+ goto done;
47+ }
48 
49- if (from > mtd->size)
50- return -EINVAL;
51     if (from + len > mtd->size)
52         len = mtd->size - from;
53 
54@@ -122,10 +138,14 @@ static int block2mtd_read(struct mtd_inf
55         len = len - cpylen;
56 
57         page = page_read(dev->blkdev->bd_inode->i_mapping, index);
58- if (!page)
59- return -ENOMEM;
60- if (IS_ERR(page))
61- return PTR_ERR(page);
62+ if (!page) {
63+ err = -ENOMEM;
64+ goto done;
65+ }
66+ if (IS_ERR(page)) {
67+ err = PTR_ERR(page);
68+ goto done;
69+ }
70 
71         memcpy(buf, page_address(page) + offset, cpylen);
72         page_cache_release(page);
73@@ -136,7 +156,10 @@ static int block2mtd_read(struct mtd_inf
74         offset = 0;
75         index++;
76     }
77- return 0;
78+
79+done:
80+ read_unlock(&dev->bdev_mutex);
81+ return err;
82 }
83 
84 
85@@ -188,12 +211,22 @@ static int block2mtd_write(struct mtd_in
86         size_t *retlen, const u_char *buf)
87 {
88     struct block2mtd_dev *dev = mtd->priv;
89- int err;
90+ int err = 0;
91+
92+ read_lock(&dev->bdev_mutex);
93+ if (!dev->blkdev) {
94+ err = -EINVAL;
95+ goto done;
96+ }
97 
98     if (!len)
99- return 0;
100- if (to >= mtd->size)
101- return -ENOSPC;
102+ goto done;
103+
104+ if (to >= mtd->size) {
105+ err = -ENOSPC;
106+ goto done;
107+ }
108+
109     if (to + len > mtd->size)
110         len = mtd->size - to;
111 
112@@ -202,6 +235,9 @@ static int block2mtd_write(struct mtd_in
113     mutex_unlock(&dev->write_mutex);
114     if (err > 0)
115         err = 0;
116+
117+done:
118+ read_unlock(&dev->bdev_mutex);
119     return err;
120 }
121 
122@@ -210,52 +246,29 @@ static int block2mtd_write(struct mtd_in
123 static void block2mtd_sync(struct mtd_info *mtd)
124 {
125     struct block2mtd_dev *dev = mtd->priv;
126- sync_blockdev(dev->blkdev);
127- return;
128-}
129-
130-
131-static void block2mtd_free_device(struct block2mtd_dev *dev)
132-{
133- if (!dev)
134- return;
135-
136- kfree(dev->mtd.name);
137 
138- if (dev->blkdev) {
139- invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
140- 0, -1);
141- close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
142- }
143+ read_lock(&dev->bdev_mutex);
144+ if (dev->blkdev)
145+ sync_blockdev(dev->blkdev);
146+ read_unlock(&dev->bdev_mutex);
147 
148- kfree(dev);
149+ return;
150 }
151 
152 
153-/* FIXME: ensure that mtd->size % erase_size == 0 */
154-static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
155+static int _open_bdev(struct block2mtd_dev *dev)
156 {
157     struct block_device *bdev;
158- struct block2mtd_dev *dev;
159- struct mtd_partition *part;
160- char *name;
161-
162- if (!devname)
163- return NULL;
164-
165- dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
166- if (!dev)
167- return NULL;
168 
169     /* Get a handle on the device */
170- bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, NULL);
171+ bdev = open_bdev_exclusive(dev->devname, FMODE_READ|FMODE_WRITE, NULL);
172 #ifndef MODULE
173     if (IS_ERR(bdev)) {
174 
175         /* We might not have rootfs mounted at this point. Try
176            to resolve the device name by other means. */
177 
178- dev_t devt = name_to_dev_t(devname);
179+ dev_t devt = name_to_dev_t(dev->devname);
180         if (devt) {
181             bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
182         }
183@@ -263,17 +276,98 @@ static struct block2mtd_dev *add_device(
184 #endif
185 
186     if (IS_ERR(bdev)) {
187- ERROR("error: cannot open device %s", devname);
188- goto devinit_err;
189+ ERROR("error: cannot open device %s", dev->devname);
190+ return 1;
191     }
192     dev->blkdev = bdev;
193 
194     if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
195         ERROR("attempting to use an MTD device as a block device");
196- goto devinit_err;
197+ return 1;
198     }
199 
200+ return 0;
201+}
202+
203+static void _close_bdev(struct block2mtd_dev *dev)
204+{
205+ struct block_device *bdev;
206+
207+ if (!dev->blkdev)
208+ return;
209+
210+ bdev = dev->blkdev;
211+ invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
212+ close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
213+ dev->blkdev = NULL;
214+}
215+
216+static void block2mtd_free_device(struct block2mtd_dev *dev)
217+{
218+ if (!dev)
219+ return;
220+
221+ kfree(dev->mtd.name);
222+ _close_bdev(dev);
223+ kfree(dev);
224+}
225+
226+
227+static int block2mtd_refresh(struct mtd_info *mtd)
228+{
229+ struct block2mtd_dev *dev = mtd->priv;
230+ struct block_device *bdev;
231+ dev_t devt;
232+ int err = 0;
233+
234+ /* no other mtd function can run at this point */
235+ write_lock(&dev->bdev_mutex);
236+
237+ /* get the device number for the whole disk */
238+ devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
239+
240+ /* close the old block device */
241+ _close_bdev(dev);
242+
243+ /* open the whole disk, issue a partition rescan, then */
244+ bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
245+ if (!bdev || !bdev->bd_disk)
246+ err = -EINVAL;
247+#ifndef CONFIG_MTD_BLOCK2MTD_MODULE
248+ else
249+ err = rescan_partitions(bdev->bd_disk, bdev);
250+#endif
251+ if (bdev)
252+ close_bdev_exclusive(bdev, FMODE_READ|FMODE_WRITE);
253+
254+ /* try to open the partition block device again */
255+ _open_bdev(dev);
256+ write_unlock(&dev->bdev_mutex);
257+
258+ return err;
259+}
260+
261+/* FIXME: ensure that mtd->size % erase_size == 0 */
262+static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
263+{
264+ struct block2mtd_dev *dev;
265+ struct mtd_partition *part;
266+ char *name;
267+
268+ if (!devname)
269+ return NULL;
270+
271+ dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
272+ if (!dev)
273+ return NULL;
274+
275+ strcpy(dev->devname, devname);
276+
277+ if (_open_bdev(dev))
278+ goto devinit_err;
279+
280     mutex_init(&dev->write_mutex);
281+ rwlock_init(&dev->bdev_mutex);
282 
283     /* Setup the MTD structure */
284     /* make the name contain the block device in */
285@@ -298,6 +392,7 @@ static struct block2mtd_dev *add_device(
286     dev->mtd.read = block2mtd_read;
287     dev->mtd.priv = dev;
288     dev->mtd.owner = THIS_MODULE;
289+ dev->mtd.refresh_device = block2mtd_refresh;
290 
291     part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
292     part->name = dev->mtd.name;
293

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