string: factorize skip_spaces and export it to be generally available
[safe/jmp/linux-2.6] / drivers / md / md.c
index d79a406..e1f3c17 100644 (file)
@@ -44,6 +44,7 @@
 #include <linux/random.h>
 #include <linux/reboot.h>
 #include <linux/file.h>
+#include <linux/compat.h>
 #include <linux/delay.h>
 #include <linux/raid/md_p.h>
 #include <linux/raid/md_u.h>
@@ -68,6 +69,12 @@ static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
 
 /*
+ * Default number of read corrections we'll attempt on an rdev
+ * before ejecting it from the array. We divide the read error
+ * count by 2 for every hour elapsed between read errors.
+ */
+#define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
+/*
  * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
  * is 1000 KB/sec, so the extra system load does not show up that much.
  * Increase it if you want to have more _guaranteed_ speed. Note that
@@ -213,12 +220,12 @@ static int md_make_request(struct request_queue *q, struct bio *bio)
                return 0;
        }
        rcu_read_lock();
-       if (mddev->suspended) {
+       if (mddev->suspended || mddev->barrier) {
                DEFINE_WAIT(__wait);
                for (;;) {
                        prepare_to_wait(&mddev->sb_wait, &__wait,
                                        TASK_UNINTERRUPTIBLE);
-                       if (!mddev->suspended)
+                       if (!mddev->suspended && !mddev->barrier)
                                break;
                        rcu_read_unlock();
                        schedule();
@@ -260,10 +267,110 @@ static void mddev_resume(mddev_t *mddev)
 
 int mddev_congested(mddev_t *mddev, int bits)
 {
+       if (mddev->barrier)
+               return 1;
        return mddev->suspended;
 }
 EXPORT_SYMBOL(mddev_congested);
 
+/*
+ * Generic barrier handling for md
+ */
+
+#define POST_REQUEST_BARRIER ((void*)1)
+
+static void md_end_barrier(struct bio *bio, int err)
+{
+       mdk_rdev_t *rdev = bio->bi_private;
+       mddev_t *mddev = rdev->mddev;
+       if (err == -EOPNOTSUPP && mddev->barrier != POST_REQUEST_BARRIER)
+               set_bit(BIO_EOPNOTSUPP, &mddev->barrier->bi_flags);
+
+       rdev_dec_pending(rdev, mddev);
+
+       if (atomic_dec_and_test(&mddev->flush_pending)) {
+               if (mddev->barrier == POST_REQUEST_BARRIER) {
+                       /* This was a post-request barrier */
+                       mddev->barrier = NULL;
+                       wake_up(&mddev->sb_wait);
+               } else
+                       /* The pre-request barrier has finished */
+                       schedule_work(&mddev->barrier_work);
+       }
+       bio_put(bio);
+}
+
+static void submit_barriers(mddev_t *mddev)
+{
+       mdk_rdev_t *rdev;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
+               if (rdev->raid_disk >= 0 &&
+                   !test_bit(Faulty, &rdev->flags)) {
+                       /* Take two references, one is dropped
+                        * when request finishes, one after
+                        * we reclaim rcu_read_lock
+                        */
+                       struct bio *bi;
+                       atomic_inc(&rdev->nr_pending);
+                       atomic_inc(&rdev->nr_pending);
+                       rcu_read_unlock();
+                       bi = bio_alloc(GFP_KERNEL, 0);
+                       bi->bi_end_io = md_end_barrier;
+                       bi->bi_private = rdev;
+                       bi->bi_bdev = rdev->bdev;
+                       atomic_inc(&mddev->flush_pending);
+                       submit_bio(WRITE_BARRIER, bi);
+                       rcu_read_lock();
+                       rdev_dec_pending(rdev, mddev);
+               }
+       rcu_read_unlock();
+}
+
+static void md_submit_barrier(struct work_struct *ws)
+{
+       mddev_t *mddev = container_of(ws, mddev_t, barrier_work);
+       struct bio *bio = mddev->barrier;
+
+       atomic_set(&mddev->flush_pending, 1);
+
+       if (test_bit(BIO_EOPNOTSUPP, &bio->bi_flags))
+               bio_endio(bio, -EOPNOTSUPP);
+       else if (bio->bi_size == 0)
+               /* an empty barrier - all done */
+               bio_endio(bio, 0);
+       else {
+               bio->bi_rw &= ~(1<<BIO_RW_BARRIER);
+               if (mddev->pers->make_request(mddev->queue, bio))
+                       generic_make_request(bio);
+               mddev->barrier = POST_REQUEST_BARRIER;
+               submit_barriers(mddev);
+       }
+       if (atomic_dec_and_test(&mddev->flush_pending)) {
+               mddev->barrier = NULL;
+               wake_up(&mddev->sb_wait);
+       }
+}
+
+void md_barrier_request(mddev_t *mddev, struct bio *bio)
+{
+       spin_lock_irq(&mddev->write_lock);
+       wait_event_lock_irq(mddev->sb_wait,
+                           !mddev->barrier,
+                           mddev->write_lock, /*nothing*/);
+       mddev->barrier = bio;
+       spin_unlock_irq(&mddev->write_lock);
+
+       atomic_set(&mddev->flush_pending, 1);
+       INIT_WORK(&mddev->barrier_work, md_submit_barrier);
+
+       submit_barriers(mddev);
+
+       if (atomic_dec_and_test(&mddev->flush_pending))
+               schedule_work(&mddev->barrier_work);
+}
+EXPORT_SYMBOL(md_barrier_request);
 
 static inline mddev_t *mddev_get(mddev_t *mddev)
 {
@@ -363,7 +470,7 @@ static mddev_t * mddev_find(dev_t unit)
 
        mutex_init(&new->open_mutex);
        mutex_init(&new->reconfig_mutex);
-       mutex_init(&new->bitmap_mutex);
+       mutex_init(&new->bitmap_info.mutex);
        INIT_LIST_HEAD(&new->disks);
        INIT_LIST_HEAD(&new->all_mddevs);
        init_timer(&new->safemode_timer);
@@ -371,6 +478,7 @@ static mddev_t * mddev_find(dev_t unit)
        atomic_set(&new->openers, 0);
        atomic_set(&new->active_io, 0);
        spin_lock_init(&new->write_lock);
+       atomic_set(&new->flush_pending, 0);
        init_waitqueue_head(&new->sb_wait);
        init_waitqueue_head(&new->recovery_wait);
        new->reshape_position = MaxSector;
@@ -749,7 +857,7 @@ struct super_type  {
  */
 int md_check_no_bitmap(mddev_t *mddev)
 {
-       if (!mddev->bitmap_file && !mddev->bitmap_offset)
+       if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
                return 0;
        printk(KERN_ERR "%s: bitmaps are not supported for %s\n",
                mdname(mddev), mddev->pers->name);
@@ -877,8 +985,8 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
                mddev->raid_disks = sb->raid_disks;
                mddev->dev_sectors = sb->size * 2;
                mddev->events = ev1;
-               mddev->bitmap_offset = 0;
-               mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
+               mddev->bitmap_info.offset = 0;
+               mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
 
                if (mddev->minor_version >= 91) {
                        mddev->reshape_position = sb->reshape_position;
@@ -912,8 +1020,9 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
                mddev->max_disks = MD_SB_DISKS;
 
                if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
-                   mddev->bitmap_file == NULL)
-                       mddev->bitmap_offset = mddev->default_bitmap_offset;
+                   mddev->bitmap_info.file == NULL)
+                       mddev->bitmap_info.offset =
+                               mddev->bitmap_info.default_offset;
 
        } else if (mddev->pers == NULL) {
                /* Insist on good event counter while assembling */
@@ -1030,7 +1139,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
        sb->layout = mddev->layout;
        sb->chunk_size = mddev->chunk_sectors << 9;
 
-       if (mddev->bitmap && mddev->bitmap_file == NULL)
+       if (mddev->bitmap && mddev->bitmap_info.file == NULL)
                sb->state |= (1<<MD_SB_BITMAP_PRESENT);
 
        sb->disks[0].state = (1<<MD_DISK_REMOVED);
@@ -1108,7 +1217,7 @@ super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
 {
        if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
                return 0; /* component must fit device */
-       if (rdev->mddev->bitmap_offset)
+       if (rdev->mddev->bitmap_info.offset)
                return 0; /* can't move bitmap */
        rdev->sb_start = calc_dev_sboffset(rdev->bdev);
        if (!num_sectors || num_sectors > rdev->sb_start)
@@ -1287,8 +1396,8 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
                mddev->raid_disks = le32_to_cpu(sb->raid_disks);
                mddev->dev_sectors = le64_to_cpu(sb->size);
                mddev->events = ev1;
-               mddev->bitmap_offset = 0;
-               mddev->default_bitmap_offset = 1024 >> 9;
+               mddev->bitmap_info.offset = 0;
+               mddev->bitmap_info.default_offset = 1024 >> 9;
                
                mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
                memcpy(mddev->uuid, sb->set_uuid, 16);
@@ -1296,8 +1405,9 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
                mddev->max_disks =  (4096-256)/2;
 
                if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
-                   mddev->bitmap_file == NULL )
-                       mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
+                   mddev->bitmap_info.file == NULL )
+                       mddev->bitmap_info.offset =
+                               (__s32)le32_to_cpu(sb->bitmap_offset);
 
                if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
                        mddev->reshape_position = le64_to_cpu(sb->reshape_position);
@@ -1391,19 +1501,17 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
        sb->level = cpu_to_le32(mddev->level);
        sb->layout = cpu_to_le32(mddev->layout);
 
-       if (mddev->bitmap && mddev->bitmap_file == NULL) {
-               sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
+       if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
+               sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
                sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
        }
 
        if (rdev->raid_disk >= 0 &&
            !test_bit(In_sync, &rdev->flags)) {
-               if (rdev->recovery_offset > 0) {
-                       sb->feature_map |=
-                               cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
-                       sb->recovery_offset =
-                               cpu_to_le64(rdev->recovery_offset);
-               }
+               sb->feature_map |=
+                       cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
+               sb->recovery_offset =
+                       cpu_to_le64(rdev->recovery_offset);
        }
 
        if (mddev->reshape_position != MaxSector) {
@@ -1437,7 +1545,7 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
                        sb->dev_roles[i] = cpu_to_le16(0xfffe);
                else if (test_bit(In_sync, &rdev2->flags))
                        sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
-               else if (rdev2->raid_disk >= 0 && rdev2->recovery_offset > 0)
+               else if (rdev2->raid_disk >= 0)
                        sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
                else
                        sb->dev_roles[i] = cpu_to_le16(0xffff);
@@ -1459,7 +1567,7 @@ super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
                max_sectors -= rdev->data_offset;
                if (!num_sectors || num_sectors > max_sectors)
                        num_sectors = max_sectors;
-       } else if (rdev->mddev->bitmap_offset) {
+       } else if (rdev->mddev->bitmap_info.offset) {
                /* minor version 0 with bitmap we can't move */
                return 0;
        } else {
@@ -2443,12 +2551,49 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
 static struct rdev_sysfs_entry rdev_size =
 __ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
 
+
+static ssize_t recovery_start_show(mdk_rdev_t *rdev, char *page)
+{
+       unsigned long long recovery_start = rdev->recovery_offset;
+
+       if (test_bit(In_sync, &rdev->flags) ||
+           recovery_start == MaxSector)
+               return sprintf(page, "none\n");
+
+       return sprintf(page, "%llu\n", recovery_start);
+}
+
+static ssize_t recovery_start_store(mdk_rdev_t *rdev, const char *buf, size_t len)
+{
+       unsigned long long recovery_start;
+
+       if (cmd_match(buf, "none"))
+               recovery_start = MaxSector;
+       else if (strict_strtoull(buf, 10, &recovery_start))
+               return -EINVAL;
+
+       if (rdev->mddev->pers &&
+           rdev->raid_disk >= 0)
+               return -EBUSY;
+
+       rdev->recovery_offset = recovery_start;
+       if (recovery_start == MaxSector)
+               set_bit(In_sync, &rdev->flags);
+       else
+               clear_bit(In_sync, &rdev->flags);
+       return len;
+}
+
+static struct rdev_sysfs_entry rdev_recovery_start =
+__ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
+
 static struct attribute *rdev_default_attrs[] = {
        &rdev_state.attr,
        &rdev_errors.attr,
        &rdev_slot.attr,
        &rdev_offset.attr,
        &rdev_size.attr,
+       &rdev_recovery_start.attr,
        NULL,
 };
 static ssize_t
@@ -2550,6 +2695,8 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
        rdev->flags = 0;
        rdev->data_offset = 0;
        rdev->sb_events = 0;
+       rdev->last_read_error.tv_sec  = 0;
+       rdev->last_read_error.tv_nsec = 0;
        atomic_set(&rdev->nr_pending, 0);
        atomic_set(&rdev->read_errors, 0);
        atomic_set(&rdev->corrected_errors, 0);
@@ -2660,6 +2807,47 @@ static void analyze_sbs(mddev_t * mddev)
        }
 }
 
+/* Read a fixed-point number.
+ * Numbers in sysfs attributes should be in "standard" units where
+ * possible, so time should be in seconds.
+ * However we internally use a a much smaller unit such as 
+ * milliseconds or jiffies.
+ * This function takes a decimal number with a possible fractional
+ * component, and produces an integer which is the result of
+ * multiplying that number by 10^'scale'.
+ * all without any floating-point arithmetic.
+ */
+int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
+{
+       unsigned long result = 0;
+       long decimals = -1;
+       while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
+               if (*cp == '.')
+                       decimals = 0;
+               else if (decimals < scale) {
+                       unsigned int value;
+                       value = *cp - '0';
+                       result = result * 10 + value;
+                       if (decimals >= 0)
+                               decimals++;
+               }
+               cp++;
+       }
+       if (*cp == '\n')
+               cp++;
+       if (*cp)
+               return -EINVAL;
+       if (decimals < 0)
+               decimals = 0;
+       while (decimals < scale) {
+               result *= 10;
+               decimals ++;
+       }
+       *res = result;
+       return 0;
+}
+
+
 static void md_safemode_timeout(unsigned long data);
 
 static ssize_t
@@ -2671,31 +2859,10 @@ safe_delay_show(mddev_t *mddev, char *page)
 static ssize_t
 safe_delay_store(mddev_t *mddev, const char *cbuf, size_t len)
 {
-       int scale=1;
-       int dot=0;
-       int i;
        unsigned long msec;
-       char buf[30];
 
-       /* remove a period, and count digits after it */
-       if (len >= sizeof(buf))
+       if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
                return -EINVAL;
-       strlcpy(buf, cbuf, sizeof(buf));
-       for (i=0; i<len; i++) {
-               if (dot) {
-                       if (isdigit(buf[i])) {
-                               buf[i-1] = buf[i];
-                               scale *= 10;
-                       }
-                       buf[i] = 0;
-               } else if (buf[i] == '.') {
-                       dot=1;
-                       buf[i] = 0;
-               }
-       }
-       if (strict_strtoul(buf, 10, &msec) < 0)
-               return -EINVAL;
-       msec = (msec * 1000) / scale;
        if (msec == 0)
                mddev->safemode_delay = 0;
        else {
@@ -2971,7 +3138,9 @@ resync_start_store(mddev_t *mddev, const char *buf, size_t len)
 
        if (mddev->pers)
                return -EBUSY;
-       if (!*buf || (*e && *e != '\n'))
+       if (cmd_match(buf, "none"))
+               n = MaxSector;
+       else if (!*buf || (*e && *e != '\n'))
                return -EINVAL;
 
        mddev->recovery_cp = n;
@@ -3167,6 +3336,29 @@ static struct md_sysfs_entry md_array_state =
 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
 
 static ssize_t
+max_corrected_read_errors_show(mddev_t *mddev, char *page) {
+       return sprintf(page, "%d\n",
+                      atomic_read(&mddev->max_corr_read_errors));
+}
+
+static ssize_t
+max_corrected_read_errors_store(mddev_t *mddev, const char *buf, size_t len)
+{
+       char *e;
+       unsigned long n = simple_strtoul(buf, &e, 10);
+
+       if (*buf && (*e == 0 || *e == '\n')) {
+               atomic_set(&mddev->max_corr_read_errors, n);
+               return len;
+       }
+       return -EINVAL;
+}
+
+static struct md_sysfs_entry max_corr_read_errors =
+__ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
+       max_corrected_read_errors_store);
+
+static ssize_t
 null_show(mddev_t *mddev, char *page)
 {
        return -EINVAL;
@@ -3791,6 +3983,7 @@ static struct attribute *md_default_attrs[] = {
        &md_array_state.attr,
        &md_reshape_position.attr,
        &md_array_size.attr,
+       &max_corr_read_errors.attr,
        NULL,
 };
 
@@ -3895,6 +4088,7 @@ static void mddev_delayed_delete(struct work_struct *ws)
                mddev->sysfs_action = NULL;
                mddev->private = NULL;
        }
+       sysfs_remove_group(&mddev->kobj, &md_bitmap_group);
        kobject_del(&mddev->kobj);
        kobject_put(&mddev->kobj);
 }
@@ -3986,6 +4180,8 @@ static int md_alloc(dev_t dev, char *name)
                       disk->disk_name);
                error = 0;
        }
+       if (sysfs_create_group(&mddev->kobj, &md_bitmap_group))
+               printk(KERN_DEBUG "pointless warning\n");
  abort:
        mutex_unlock(&disks_mutex);
        if (!error) {
@@ -4207,6 +4403,8 @@ static int do_md_run(mddev_t * mddev)
                mddev->ro = 0;
 
        atomic_set(&mddev->writes_pending,0);
+       atomic_set(&mddev->max_corr_read_errors,
+                  MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
        mddev->safemode = 0;
        mddev->safemode_timer.function = md_safemode_timeout;
        mddev->safemode_timer.data = (unsigned long) mddev;
@@ -4311,7 +4509,7 @@ static int deny_bitmap_write_access(struct file * file)
        return 0;
 }
 
-static void restore_bitmap_write_access(struct file *file)
+void restore_bitmap_write_access(struct file *file)
 {
        struct inode *inode = file->f_mapping->host;
 
@@ -4406,12 +4604,12 @@ out:
                printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
 
                bitmap_destroy(mddev);
-               if (mddev->bitmap_file) {
-                       restore_bitmap_write_access(mddev->bitmap_file);
-                       fput(mddev->bitmap_file);
-                       mddev->bitmap_file = NULL;
+               if (mddev->bitmap_info.file) {
+                       restore_bitmap_write_access(mddev->bitmap_info.file);
+                       fput(mddev->bitmap_info.file);
+                       mddev->bitmap_info.file = NULL;
                }
-               mddev->bitmap_offset = 0;
+               mddev->bitmap_info.offset = 0;
 
                /* make sure all md_delayed_delete calls have finished */
                flush_scheduled_work();
@@ -4452,6 +4650,11 @@ out:
                mddev->degraded = 0;
                mddev->barriers_work = 0;
                mddev->safemode = 0;
+               mddev->bitmap_info.offset = 0;
+               mddev->bitmap_info.default_offset = 0;
+               mddev->bitmap_info.chunksize = 0;
+               mddev->bitmap_info.daemon_sleep = 0;
+               mddev->bitmap_info.max_write_behind = 0;
                kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
                if (mddev->hold_active == UNTIL_STOP)
                        mddev->hold_active = 0;
@@ -4637,7 +4840,7 @@ static int get_array_info(mddev_t * mddev, void __user * arg)
        info.state         = 0;
        if (mddev->in_sync)
                info.state = (1<<MD_SB_CLEAN);
-       if (mddev->bitmap && mddev->bitmap_offset)
+       if (mddev->bitmap && mddev->bitmap_info.offset)
                info.state = (1<<MD_SB_BITMAP_PRESENT);
        info.active_disks  = insync;
        info.working_disks = working;
@@ -4995,23 +5198,23 @@ static int set_bitmap_file(mddev_t *mddev, int fd)
        if (fd >= 0) {
                if (mddev->bitmap)
                        return -EEXIST; /* cannot add when bitmap is present */
-               mddev->bitmap_file = fget(fd);
+               mddev->bitmap_info.file = fget(fd);
 
-               if (mddev->bitmap_file == NULL) {
+               if (mddev->bitmap_info.file == NULL) {
                        printk(KERN_ERR "%s: error: failed to get bitmap file\n",
                               mdname(mddev));
                        return -EBADF;
                }
 
-               err = deny_bitmap_write_access(mddev->bitmap_file);
+               err = deny_bitmap_write_access(mddev->bitmap_info.file);
                if (err) {
                        printk(KERN_ERR "%s: error: bitmap file is already in use\n",
                               mdname(mddev));
-                       fput(mddev->bitmap_file);
-                       mddev->bitmap_file = NULL;
+                       fput(mddev->bitmap_info.file);
+                       mddev->bitmap_info.file = NULL;
                        return err;
                }
-               mddev->bitmap_offset = 0; /* file overrides offset */
+               mddev->bitmap_info.offset = 0; /* file overrides offset */
        } else if (mddev->bitmap == NULL)
                return -ENOENT; /* cannot remove what isn't there */
        err = 0;
@@ -5026,11 +5229,11 @@ static int set_bitmap_file(mddev_t *mddev, int fd)
                mddev->pers->quiesce(mddev, 0);
        }
        if (fd < 0) {
-               if (mddev->bitmap_file) {
-                       restore_bitmap_write_access(mddev->bitmap_file);
-                       fput(mddev->bitmap_file);
+               if (mddev->bitmap_info.file) {
+                       restore_bitmap_write_access(mddev->bitmap_info.file);
+                       fput(mddev->bitmap_info.file);
                }
-               mddev->bitmap_file = NULL;
+               mddev->bitmap_info.file = NULL;
        }
 
        return err;
@@ -5097,8 +5300,8 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
                mddev->flags         = 0;
        set_bit(MD_CHANGE_DEVS, &mddev->flags);
 
-       mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
-       mddev->bitmap_offset = 0;
+       mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
+       mddev->bitmap_info.offset = 0;
 
        mddev->reshape_position = MaxSector;
 
@@ -5198,7 +5401,7 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
        int state = 0;
 
        /* calculate expected state,ignoring low bits */
-       if (mddev->bitmap && mddev->bitmap_offset)
+       if (mddev->bitmap && mddev->bitmap_info.offset)
                state |= (1 << MD_SB_BITMAP_PRESENT);
 
        if (mddev->major_version != info->major_version ||
@@ -5257,9 +5460,10 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
                        /* add the bitmap */
                        if (mddev->bitmap)
                                return -EEXIST;
-                       if (mddev->default_bitmap_offset == 0)
+                       if (mddev->bitmap_info.default_offset == 0)
                                return -EINVAL;
-                       mddev->bitmap_offset = mddev->default_bitmap_offset;
+                       mddev->bitmap_info.offset =
+                               mddev->bitmap_info.default_offset;
                        mddev->pers->quiesce(mddev, 1);
                        rv = bitmap_create(mddev);
                        if (rv)
@@ -5274,7 +5478,7 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
                        mddev->pers->quiesce(mddev, 1);
                        bitmap_destroy(mddev);
                        mddev->pers->quiesce(mddev, 0);
-                       mddev->bitmap_offset = 0;
+                       mddev->bitmap_info.offset = 0;
                }
        }
        md_update_sb(mddev, 1);
@@ -5525,6 +5729,25 @@ done:
 abort:
        return err;
 }
+#ifdef CONFIG_COMPAT
+static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
+                   unsigned int cmd, unsigned long arg)
+{
+       switch (cmd) {
+       case HOT_REMOVE_DISK:
+       case HOT_ADD_DISK:
+       case SET_DISK_FAULTY:
+       case SET_BITMAP_FILE:
+               /* These take in integer arg, do not convert */
+               break;
+       default:
+               arg = (unsigned long)compat_ptr(arg);
+               break;
+       }
+
+       return md_ioctl(bdev, mode, cmd, arg);
+}
+#endif /* CONFIG_COMPAT */
 
 static int md_open(struct block_device *bdev, fmode_t mode)
 {
@@ -5590,6 +5813,9 @@ static const struct block_device_operations md_fops =
        .open           = md_open,
        .release        = md_release,
        .ioctl          = md_ioctl,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl   = md_compat_ioctl,
+#endif
        .getgeo         = md_getgeo,
        .media_changed  = md_media_changed,
        .revalidate_disk= md_revalidate,
@@ -5983,14 +6209,14 @@ static int md_seq_show(struct seq_file *seq, void *v)
                        unsigned long chunk_kb;
                        unsigned long flags;
                        spin_lock_irqsave(&bitmap->lock, flags);
-                       chunk_kb = bitmap->chunksize >> 10;
+                       chunk_kb = mddev->bitmap_info.chunksize >> 10;
                        seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
                                "%lu%s chunk",
                                bitmap->pages - bitmap->missing_pages,
                                bitmap->pages,
                                (bitmap->pages - bitmap->missing_pages)
                                        << (PAGE_SHIFT - 10),
-                               chunk_kb ? chunk_kb : bitmap->chunksize,
+                               chunk_kb ? chunk_kb : mddev->bitmap_info.chunksize,
                                chunk_kb ? "KB" : "B");
                        if (bitmap->file) {
                                seq_printf(seq, ", file: ");
@@ -6339,12 +6565,14 @@ void md_do_sync(mddev_t *mddev)
                /* recovery follows the physical size of devices */
                max_sectors = mddev->dev_sectors;
                j = MaxSector;
-               list_for_each_entry(rdev, &mddev->disks, same_set)
+               rcu_read_lock();
+               list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
                        if (rdev->raid_disk >= 0 &&
                            !test_bit(Faulty, &rdev->flags) &&
                            !test_bit(In_sync, &rdev->flags) &&
                            rdev->recovery_offset < j)
                                j = rdev->recovery_offset;
+               rcu_read_unlock();
        }
 
        printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev));
@@ -6514,12 +6742,14 @@ void md_do_sync(mddev_t *mddev)
                } else {
                        if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
                                mddev->curr_resync = MaxSector;
-                       list_for_each_entry(rdev, &mddev->disks, same_set)
+                       rcu_read_lock();
+                       list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
                                if (rdev->raid_disk >= 0 &&
                                    !test_bit(Faulty, &rdev->flags) &&
                                    !test_bit(In_sync, &rdev->flags) &&
                                    rdev->recovery_offset < mddev->curr_resync)
                                        rdev->recovery_offset = mddev->curr_resync;
+                       rcu_read_unlock();
                }
        }
        set_bit(MD_CHANGE_DEVS, &mddev->flags);
@@ -6597,6 +6827,7 @@ static int remove_and_add_spares(mddev_t *mddev)
                                                       nm, mdname(mddev));
                                        spares++;
                                        md_new_event(mddev);
+                                       set_bit(MD_CHANGE_DEVS, &mddev->flags);
                                } else
                                        break;
                        }
@@ -7002,5 +7233,6 @@ EXPORT_SYMBOL(md_unregister_thread);
 EXPORT_SYMBOL(md_wakeup_thread);
 EXPORT_SYMBOL(md_check_recovery);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MD RAID framework");
 MODULE_ALIAS("md");
 MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);