md: support updating bitmap parameters via sysfs.
[safe/jmp/linux-2.6] / drivers / md / bitmap.c
index 9588654..24fff75 100644 (file)
@@ -510,6 +510,9 @@ void bitmap_update_sb(struct bitmap *bitmap)
                bitmap->events_cleared = bitmap->mddev->events;
                sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
        }
+       /* Just in case these have been changed via sysfs: */
+       sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
+       sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
        kunmap_atomic(sb, KM_USER0);
        write_page(bitmap, bitmap->sb_page, 1);
 }
@@ -1714,6 +1717,208 @@ int bitmap_create(mddev_t *mddev)
        return err;
 }
 
+static ssize_t
+location_show(mddev_t *mddev, char *page)
+{
+       ssize_t len;
+       if (mddev->bitmap_info.file) {
+               len = sprintf(page, "file");
+       } else if (mddev->bitmap_info.offset) {
+               len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
+       } else
+               len = sprintf(page, "none");
+       len += sprintf(page+len, "\n");
+       return len;
+}
+
+static ssize_t
+location_store(mddev_t *mddev, const char *buf, size_t len)
+{
+
+       if (mddev->pers) {
+               if (!mddev->pers->quiesce)
+                       return -EBUSY;
+               if (mddev->recovery || mddev->sync_thread)
+                       return -EBUSY;
+       }
+
+       if (mddev->bitmap || mddev->bitmap_info.file ||
+           mddev->bitmap_info.offset) {
+               /* bitmap already configured.  Only option is to clear it */
+               if (strncmp(buf, "none", 4) != 0)
+                       return -EBUSY;
+               if (mddev->pers) {
+                       mddev->pers->quiesce(mddev, 1);
+                       bitmap_destroy(mddev);
+                       mddev->pers->quiesce(mddev, 0);
+               }
+               mddev->bitmap_info.offset = 0;
+               if (mddev->bitmap_info.file) {
+                       struct file *f = mddev->bitmap_info.file;
+                       mddev->bitmap_info.file = NULL;
+                       restore_bitmap_write_access(f);
+                       fput(f);
+               }
+       } else {
+               /* No bitmap, OK to set a location */
+               long long offset;
+               if (strncmp(buf, "none", 4) == 0)
+                       /* nothing to be done */;
+               else if (strncmp(buf, "file:", 5) == 0) {
+                       /* Not supported yet */
+                       return -EINVAL;
+               } else {
+                       int rv;
+                       if (buf[0] == '+')
+                               rv = strict_strtoll(buf+1, 10, &offset);
+                       else
+                               rv = strict_strtoll(buf, 10, &offset);
+                       if (rv)
+                               return rv;
+                       if (offset == 0)
+                               return -EINVAL;
+                       if (mddev->major_version == 0 &&
+                           offset != mddev->bitmap_info.default_offset)
+                               return -EINVAL;
+                       mddev->bitmap_info.offset = offset;
+                       if (mddev->pers) {
+                               mddev->pers->quiesce(mddev, 1);
+                               rv = bitmap_create(mddev);
+                               if (rv) {
+                                       bitmap_destroy(mddev);
+                                       mddev->bitmap_info.offset = 0;
+                               }
+                               mddev->pers->quiesce(mddev, 0);
+                               if (rv)
+                                       return rv;
+                       }
+               }
+       }
+       if (!mddev->external) {
+               /* Ensure new bitmap info is stored in
+                * metadata promptly.
+                */
+               set_bit(MD_CHANGE_DEVS, &mddev->flags);
+               md_wakeup_thread(mddev->thread);
+       }
+       return len;
+}
+
+static struct md_sysfs_entry bitmap_location =
+__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
+
+static ssize_t
+timeout_show(mddev_t *mddev, char *page)
+{
+       ssize_t len;
+       unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
+       unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
+       
+       len = sprintf(page, "%lu", secs);
+       if (jifs)
+               len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
+       len += sprintf(page+len, "\n");
+       return len;
+}
+
+static ssize_t
+timeout_store(mddev_t *mddev, const char *buf, size_t len)
+{
+       /* timeout can be set at any time */
+       unsigned long timeout;
+       int rv = strict_strtoul_scaled(buf, &timeout, 4);
+       if (rv)
+               return rv;
+
+       /* just to make sure we don't overflow... */
+       if (timeout >= LONG_MAX / HZ)
+               return -EINVAL;
+
+       timeout = timeout * HZ / 10000;
+
+       if (timeout >= MAX_SCHEDULE_TIMEOUT)
+               timeout = MAX_SCHEDULE_TIMEOUT-1;
+       if (timeout < 1)
+               timeout = 1;
+       mddev->bitmap_info.daemon_sleep = timeout;
+       if (mddev->thread) {
+               /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
+                * the bitmap is all clean and we don't need to
+                * adjust the timeout right now
+                */
+               if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
+                       mddev->thread->timeout = timeout;
+                       md_wakeup_thread(mddev->thread);
+               }
+       }
+       return len;
+}
+
+static struct md_sysfs_entry bitmap_timeout =
+__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
+
+static ssize_t
+backlog_show(mddev_t *mddev, char *page)
+{
+       return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
+}
+
+static ssize_t
+backlog_store(mddev_t *mddev, const char *buf, size_t len)
+{
+       unsigned long backlog;
+       int rv = strict_strtoul(buf, 10, &backlog);
+       if (rv)
+               return rv;
+       if (backlog > COUNTER_MAX)
+               return -EINVAL;
+       mddev->bitmap_info.max_write_behind = backlog;
+       return len;
+}
+
+static struct md_sysfs_entry bitmap_backlog =
+__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
+
+static ssize_t
+chunksize_show(mddev_t *mddev, char *page)
+{
+       return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
+}
+
+static ssize_t
+chunksize_store(mddev_t *mddev, const char *buf, size_t len)
+{
+       /* Can only be changed when no bitmap is active */
+       int rv;
+       unsigned long csize;
+       if (mddev->bitmap)
+               return -EBUSY;
+       rv = strict_strtoul(buf, 10, &csize);
+       if (rv)
+               return rv;
+       if (csize < 512 ||
+           !is_power_of_2(csize))
+               return -EINVAL;
+       mddev->bitmap_info.chunksize = csize;
+       return len;
+}
+
+static struct md_sysfs_entry bitmap_chunksize =
+__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
+
+static struct attribute *md_bitmap_attrs[] = {
+       &bitmap_location.attr,
+       &bitmap_timeout.attr,
+       &bitmap_backlog.attr,
+       &bitmap_chunksize.attr,
+       NULL
+};
+struct attribute_group md_bitmap_group = {
+       .name = "bitmap",
+       .attrs = md_bitmap_attrs,
+};
+
+
 /* the bitmap API -- for raid personalities */
 EXPORT_SYMBOL(bitmap_startwrite);
 EXPORT_SYMBOL(bitmap_endwrite);