Merge branch 'for-linus' of git://neil.brown.name/md

* 'for-linus' of git://neil.brown.name/md: (27 commits)
  md: add 'recovery_start' per-device sysfs attribute
  md: rcu_read_lock() walk of mddev->disks in md_do_sync()
  md: integrate spares into array at earliest opportunity.
  md: move compat_ioctl handling into md.c
  md: revise Kconfig help for MD_MULTIPATH
  md: add MODULE_DESCRIPTION for all md related modules.
  raid: improve MD/raid10 handling of correctable read errors.
  md/raid10: print more useful messages on device failure.
  md/bitmap: update dirty flag when bitmap bits are explicitly set.
  md: Support write-intent bitmaps with externally managed metadata.
  md/bitmap: move setting of daemon_lastrun out of bitmap_read_sb
  md: support updating bitmap parameters via sysfs.
  md: factor out parsing of fixed-point numbers
  md: support bitmap offset appropriate for external-metadata arrays.
  md: remove needless setting of thread->timeout in raid10_quiesce
  md: change daemon_sleep to be in 'jiffies' rather than 'seconds'.
  md: move offset, daemon_sleep and chunksize out of bitmap structure
  md: collect bitmap-specific fields into one structure.
  md/raid1: add takeover support for raid5->raid1
  md: add honouring of suspend_{lo,hi} to raid1.
  ...

17 files changed, 1146 insertions, 315 deletions

diff --git a/Documentation/md.txt b/Documentation/md.txt
index 4edd39ec7db9..188f4768f1d5 100644
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -233,9 +233,9 @@ All md devices contain:
 
   resync_start
      The point at which resync should start.  If no resync is needed,
-     this will be a very large number.  At array creation it will
-     default to 0, though starting the array as 'clean' will
-     set it much larger.
+     this will be a very large number (or 'none' since 2.6.30-rc1).  At
+     array creation it will default to 0, though starting the array as
+     'clean' will set it much larger.
 
    new_dev
      This file can be written but not read.  The value written should
@@ -296,6 +296,51 @@ All md devices contain:
      active-idle
          like active, but no writes have been seen for a while (safe_mode_delay).
 
+  bitmap/location
+     This indicates where the write-intent bitmap for the array is
+     stored.
+     It can be one of "none", "file" or "[+-]N".
+     "file" may later be extended to "file:/file/name"
+     "[+-]N" means that many sectors from the start of the metadata.
+       This is replicated on all devices.  For arrays with externally
+       managed metadata, the offset is from the beginning of the
+       device.
+  bitmap/chunksize
+     The size, in bytes, of the chunk which will be represented by a
+     single bit.  For RAID456, it is a portion of an individual
+     device. For RAID10, it is a portion of the array.  For RAID1, it
+     is both (they come to the same thing).
+  bitmap/time_base
+     The time, in seconds, between looking for bits in the bitmap to
+     be cleared. In the current implementation, a bit will be cleared
+     between 2 and 3 times "time_base" after all the covered blocks
+     are known to be in-sync.
+  bitmap/backlog
+     When write-mostly devices are active in a RAID1, write requests
+     to those devices proceed in the background - the filesystem (or
+     other user of the device) does not have to wait for them.
+     'backlog' sets a limit on the number of concurrent background
+     writes.  If there are more than this, new writes will by
+     synchronous.
+  bitmap/metadata
+     This can be either 'internal' or 'external'.
+     'internal' is the default and means the metadata for the bitmap
+     is stored in the first 256 bytes of the allocated space and is
+     managed by the md module.
+     'external' means that bitmap metadata is managed externally to
+     the kernel (i.e. by some userspace program)
+  bitmap/can_clear
+     This is either 'true' or 'false'.  If 'true', then bits in the
+     bitmap will be cleared when the corresponding blocks are thought
+     to be in-sync.  If 'false', bits will never be cleared.
+     This is automatically set to 'false' if a write happens on a
+     degraded array, or if the array becomes degraded during a write.
+     When metadata is managed externally, it should be set to true
+     once the array becomes non-degraded, and this fact has been
+     recorded in the metadata.
+     
+     
+     
 
 As component devices are added to an md array, they appear in the 'md'
 directory as new directories named
@@ -334,8 +379,9 @@ Each directory contains:
         Writing "writemostly" sets the writemostly flag.
         Writing "-writemostly" clears the writemostly flag.
         Writing "blocked" sets the "blocked" flag.
-        Writing "-blocked" clear the "blocked" flag and allows writes
+        Writing "-blocked" clears the "blocked" flag and allows writes
                 to complete.
+        Writing "in_sync" sets the in_sync flag.
 
         This file responds to select/poll. Any change to 'faulty'
         or 'blocked' causes an event.
@@ -372,6 +418,24 @@ Each directory contains:
         array.  If a value less than the current component_size is
         written, it will be rejected.
 
+      recovery_start
+
+        When the device is not 'in_sync', this records the number of
+        sectors from the start of the device which are known to be
+        correct.  This is normally zero, but during a recovery
+        operation is will steadily increase, and if the recovery is
+        interrupted, restoring this value can cause recovery to
+        avoid repeating the earlier blocks.  With v1.x metadata, this
+        value is saved and restored automatically.
+
+        This can be set whenever the device is not an active member of
+        the array, either before the array is activated, or before
+        the 'slot' is set.
+
+        Setting this to 'none' is equivalent to setting 'in_sync'.
+        Setting to any other value also clears the 'in_sync' flag.
+        
+
 
 An active md device will also contain and entry for each active device
 in the array.  These are named
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 2158377a1359..acb3a4e404ff 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -185,11 +185,10 @@ config MD_MULTIPATH
         tristate "Multipath I/O support"
         depends on BLK_DEV_MD
         help
-          Multipath-IO is the ability of certain devices to address the same
-          physical disk over multiple 'IO paths'. The code ensures that such
-          paths can be defined and handled at runtime, and ensures that a
-          transparent failover to the backup path(s) happens if a IO errors
-          arrives on the primary path.
+          MD_MULTIPATH provides a simple multi-path personality for use
+          the MD framework.  It is not under active development.  New
+          projects should consider using DM_MULTIPATH which has more
+          features and more testing.
 
           If unsure, say N.
 
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 60e2b322db11..26ac8aad0b19 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -212,7 +212,7 @@ static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
  */
 
 /* IO operations when bitmap is stored near all superblocks */
-static struct page *read_sb_page(mddev_t *mddev, long offset,
+static struct page *read_sb_page(mddev_t *mddev, loff_t offset,
                                  struct page *page,
                                  unsigned long index, int size)
 {
@@ -287,27 +287,36 @@ static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
 
         while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
                         int size = PAGE_SIZE;
+                        loff_t offset = mddev->bitmap_info.offset;
                         if (page->index == bitmap->file_pages-1)
                                 size = roundup(bitmap->last_page_size,
                                                bdev_logical_block_size(rdev->bdev));
                         /* Just make sure we aren't corrupting data or
                          * metadata
                          */
-                        if (bitmap->offset < 0) {
+                        if (mddev->external) {
+                                /* Bitmap could be anywhere. */
+                                if (rdev->sb_start + offset + (page->index *(PAGE_SIZE/512)) >
+                                    rdev->data_offset &&
+                                    rdev->sb_start + offset < 
+                                    rdev->data_offset + mddev->dev_sectors +
+                                    (PAGE_SIZE/512))
+                                        goto bad_alignment;
+                        } else if (offset < 0) {
                                 /* DATA  BITMAP METADATA  */
-                                if (bitmap->offset
+                                if (offset
                                     + (long)(page->index * (PAGE_SIZE/512))
                                     + size/512 > 0)
                                         /* bitmap runs in to metadata */
                                         goto bad_alignment;
                                 if (rdev->data_offset + mddev->dev_sectors
-                                    > rdev->sb_start + bitmap->offset)
+                                    > rdev->sb_start + offset)
                                         /* data runs in to bitmap */
                                         goto bad_alignment;
                         } else if (rdev->sb_start < rdev->data_offset) {
                                 /* METADATA BITMAP DATA */
                                 if (rdev->sb_start
-                                    + bitmap->offset
+                                    + offset
                                     + page->index*(PAGE_SIZE/512) + size/512
                                     > rdev->data_offset)
                                         /* bitmap runs in to data */
@@ -316,7 +325,7 @@ static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
                                 /* DATA METADATA BITMAP - no problems */
                         }
                         md_super_write(mddev, rdev,
-                                       rdev->sb_start + bitmap->offset
+                                       rdev->sb_start + offset
                                        + page->index * (PAGE_SIZE/512),
                                        size,
                                        page);
@@ -488,6 +497,8 @@ void bitmap_update_sb(struct bitmap *bitmap)
 
         if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
                 return;
+        if (bitmap->mddev->bitmap_info.external)
+                return;
         spin_lock_irqsave(&bitmap->lock, flags);
         if (!bitmap->sb_page) { /* no superblock */
                 spin_unlock_irqrestore(&bitmap->lock, flags);
@@ -501,6 +512,9 @@ 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);
 }
@@ -550,7 +564,8 @@ static int bitmap_read_sb(struct bitmap *bitmap)
 
                 bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes);
         } else {
-                bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset,
+                bitmap->sb_page = read_sb_page(bitmap->mddev,
+                                               bitmap->mddev->bitmap_info.offset,
                                                NULL,
                                                0, sizeof(bitmap_super_t));
         }
@@ -563,7 +578,7 @@ static int bitmap_read_sb(struct bitmap *bitmap)
         sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
 
         chunksize = le32_to_cpu(sb->chunksize);
-        daemon_sleep = le32_to_cpu(sb->daemon_sleep);
+        daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
         write_behind = le32_to_cpu(sb->write_behind);
 
         /* verify that the bitmap-specific fields are valid */
@@ -576,7 +591,7 @@ static int bitmap_read_sb(struct bitmap *bitmap)
                 reason = "bitmap chunksize too small";
         else if ((1 << ffz(~chunksize)) != chunksize)
                 reason = "bitmap chunksize not a power of 2";
-        else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT / HZ)
+        else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
                 reason = "daemon sleep period out of range";
         else if (write_behind > COUNTER_MAX)
                 reason = "write-behind limit out of range (0 - 16383)";
@@ -610,10 +625,9 @@ static int bitmap_read_sb(struct bitmap *bitmap)
         }
 success:
         /* assign fields using values from superblock */
-        bitmap->chunksize = chunksize;
-        bitmap->daemon_sleep = daemon_sleep;
-        bitmap->daemon_lastrun = jiffies;
-        bitmap->max_write_behind = write_behind;
+        bitmap->mddev->bitmap_info.chunksize = chunksize;
+        bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
+        bitmap->mddev->bitmap_info.max_write_behind = write_behind;
         bitmap->flags |= le32_to_cpu(sb->state);
         if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
                 bitmap->flags |= BITMAP_HOSTENDIAN;
@@ -664,16 +678,26 @@ static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
  * general bitmap file operations
  */
 
+/*
+ * on-disk bitmap:
+ *
+ * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
+ * file a page at a time. There's a superblock at the start of the file.
+ */
 /* calculate the index of the page that contains this bit */
-static inline unsigned long file_page_index(unsigned long chunk)
+static inline unsigned long file_page_index(struct bitmap *bitmap, unsigned long chunk)
 {
-        return CHUNK_BIT_OFFSET(chunk) >> PAGE_BIT_SHIFT;
+        if (!bitmap->mddev->bitmap_info.external)
+                chunk += sizeof(bitmap_super_t) << 3;
+        return chunk >> PAGE_BIT_SHIFT;
 }
 
 /* calculate the (bit) offset of this bit within a page */
-static inline unsigned long file_page_offset(unsigned long chunk)
+static inline unsigned long file_page_offset(struct bitmap *bitmap, unsigned long chunk)
 {
-        return CHUNK_BIT_OFFSET(chunk) & (PAGE_BITS - 1);
+        if (!bitmap->mddev->bitmap_info.external)
+                chunk += sizeof(bitmap_super_t) << 3;
+        return chunk & (PAGE_BITS - 1);
 }
 
 /*
@@ -686,8 +710,9 @@ static inline unsigned long file_page_offset(unsigned long chunk)
 static inline struct page *filemap_get_page(struct bitmap *bitmap,
                                         unsigned long chunk)
 {
-        if (file_page_index(chunk) >= bitmap->file_pages) return NULL;
-        return bitmap->filemap[file_page_index(chunk) - file_page_index(0)];
+        if (file_page_index(bitmap, chunk) >= bitmap->file_pages) return NULL;
+        return bitmap->filemap[file_page_index(bitmap, chunk)
+                               - file_page_index(bitmap, 0)];
 }
 
 
@@ -710,7 +735,7 @@ static void bitmap_file_unmap(struct bitmap *bitmap)
         spin_unlock_irqrestore(&bitmap->lock, flags);
 
         while (pages--)
-                if (map[pages]->index != 0) /* 0 is sb_page, release it below */
+                if (map[pages] != sb_page) /* 0 is sb_page, release it below */
                         free_buffers(map[pages]);
         kfree(map);
         kfree(attr);
@@ -821,7 +846,7 @@ static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
 
         page = filemap_get_page(bitmap, chunk);
         if (!page) return;
-        bit = file_page_offset(chunk);
+        bit = file_page_offset(bitmap, chunk);
 
         /* set the bit */
         kaddr = kmap_atomic(page, KM_USER0);
@@ -907,7 +932,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
         chunks = bitmap->chunks;
         file = bitmap->file;
 
-        BUG_ON(!file && !bitmap->offset);
+        BUG_ON(!file && !bitmap->mddev->bitmap_info.offset);
 
 #ifdef INJECT_FAULTS_3
         outofdate = 1;
@@ -919,14 +944,17 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
                         "recovery\n", bmname(bitmap));
 
         bytes = (chunks + 7) / 8;
+        if (!bitmap->mddev->bitmap_info.external)
+                bytes += sizeof(bitmap_super_t);
 
-        num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE;
+        
+        num_pages = (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
 
-        if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) {
+        if (file && i_size_read(file->f_mapping->host) < bytes) {
                 printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
                         bmname(bitmap),
                         (unsigned long) i_size_read(file->f_mapping->host),
-                        bytes + sizeof(bitmap_super_t));
+                        bytes);
                 goto err;
         }
 
@@ -947,17 +975,16 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
 
         for (i = 0; i < chunks; i++) {
                 int b;
-                index = file_page_index(i);
-                bit = file_page_offset(i);
+                index = file_page_index(bitmap, i);
+                bit = file_page_offset(bitmap, i);
                 if (index != oldindex) { /* this is a new page, read it in */
                         int count;
                         /* unmap the old page, we're done with it */
                         if (index == num_pages-1)
-                                count = bytes + sizeof(bitmap_super_t)
-                                        - index * PAGE_SIZE;
+                                count = bytes - index * PAGE_SIZE;
                         else
                                 count = PAGE_SIZE;
-                        if (index == 0) {
+                        if (index == 0 && bitmap->sb_page) {
                                 /*
                                  * if we're here then the superblock page
                                  * contains some bits (PAGE_SIZE != sizeof sb)
@@ -967,14 +994,15 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
                                 offset = sizeof(bitmap_super_t);
                                 if (!file)
                                         read_sb_page(bitmap->mddev,
-                                                     bitmap->offset,
+                                                     bitmap->mddev->bitmap_info.offset,
                                                      page,
                                                      index, count);
                         } else if (file) {
                                 page = read_page(file, index, bitmap, count);
                                 offset = 0;
                         } else {
-                                page = read_sb_page(bitmap->mddev, bitmap->offset,
+                                page = read_sb_page(bitmap->mddev,
+                                                    bitmap->mddev->bitmap_info.offset,
                                                     NULL,
                                                     index, count);
                                 offset = 0;
@@ -1078,23 +1106,32 @@ static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
  *                      out to disk
  */
 
-void bitmap_daemon_work(struct bitmap *bitmap)
+void bitmap_daemon_work(mddev_t *mddev)
 {
+        struct bitmap *bitmap;
         unsigned long j;
         unsigned long flags;
         struct page *page = NULL, *lastpage = NULL;
         int blocks;
         void *paddr;
 
-        if (bitmap == NULL)
+        /* Use a mutex to guard daemon_work against
+         * bitmap_destroy.
+         */
+        mutex_lock(&mddev->bitmap_info.mutex);
+        bitmap = mddev->bitmap;
+        if (bitmap == NULL) {
+                mutex_unlock(&mddev->bitmap_info.mutex);
                 return;
-        if (time_before(jiffies, bitmap->daemon_lastrun + bitmap->daemon_sleep*HZ))
+        }
+        if (time_before(jiffies, bitmap->daemon_lastrun
+                        + bitmap->mddev->bitmap_info.daemon_sleep))
                 goto done;
 
         bitmap->daemon_lastrun = jiffies;
         if (bitmap->allclean) {
                 bitmap->mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
-                return;
+                goto done;
         }
         bitmap->allclean = 1;
 
@@ -1142,7 +1179,8 @@ void bitmap_daemon_work(struct bitmap *bitmap)
                         /* We are possibly going to clear some bits, so make
                          * sure that events_cleared is up-to-date.
                          */
-                        if (bitmap->need_sync) {
+                        if (bitmap->need_sync &&
+                            bitmap->mddev->bitmap_info.external == 0) {
                                 bitmap_super_t *sb;
                                 bitmap->need_sync = 0;
                                 sb = kmap_atomic(bitmap->sb_page, KM_USER0);
@@ -1152,7 +1190,8 @@ void bitmap_daemon_work(struct bitmap *bitmap)
                                 write_page(bitmap, bitmap->sb_page, 1);
                         }
                         spin_lock_irqsave(&bitmap->lock, flags);
-                        clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
+                        if (!bitmap->need_sync)
+                                clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
                 }
                 bmc = bitmap_get_counter(bitmap,
                                          (sector_t)j << CHUNK_BLOCK_SHIFT(bitmap),
@@ -1167,7 +1206,7 @@ void bitmap_daemon_work(struct bitmap *bitmap)
                         if (*bmc == 2) {
                                 *bmc=1; /* maybe clear the bit next time */
                                 set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
-                        } else if (*bmc == 1) {
+                        } else if (*bmc == 1 && !bitmap->need_sync) {
                                 /* we can clear the bit */
                                 *bmc = 0;
                                 bitmap_count_page(bitmap,
@@ -1177,9 +1216,11 @@ void bitmap_daemon_work(struct bitmap *bitmap)
                                 /* clear the bit */
                                 paddr = kmap_atomic(page, KM_USER0);
                                 if (bitmap->flags & BITMAP_HOSTENDIAN)
-                                        clear_bit(file_page_offset(j), paddr);
+                                        clear_bit(file_page_offset(bitmap, j),
+                                                  paddr);
                                 else
-                                        ext2_clear_bit(file_page_offset(j), paddr);
+                                        ext2_clear_bit(file_page_offset(bitmap, j),
+                                                       paddr);
                                 kunmap_atomic(paddr, KM_USER0);
                         }
                 } else
@@ -1202,7 +1243,9 @@ void bitmap_daemon_work(struct bitmap *bitmap)
 
  done:
         if (bitmap->allclean == 0)
-                bitmap->mddev->thread->timeout = bitmap->daemon_sleep * HZ;
+                bitmap->mddev->thread->timeout = 
+                        bitmap->mddev->bitmap_info.daemon_sleep;
+        mutex_unlock(&mddev->bitmap_info.mutex);
 }
 
 static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
@@ -1332,6 +1375,7 @@ void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long secto
                     bitmap->events_cleared < bitmap->mddev->events) {
                         bitmap->events_cleared = bitmap->mddev->events;
                         bitmap->need_sync = 1;
+                        sysfs_notify_dirent(bitmap->sysfs_can_clear);
                 }
 
                 if (!success && ! (*bmc & NEEDED_MASK))
@@ -1470,7 +1514,7 @@ void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
                 return;
         }
         if (time_before(jiffies, (bitmap->last_end_sync
-                                  + bitmap->daemon_sleep * HZ)))
+                                  + bitmap->mddev->bitmap_info.daemon_sleep)))
                 return;
         wait_event(bitmap->mddev->recovery_wait,
                    atomic_read(&bitmap->mddev->recovery_active) == 0);
@@ -1522,6 +1566,12 @@ void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
                 sector_t sec = (sector_t)chunk << CHUNK_BLOCK_SHIFT(bitmap);
                 bitmap_set_memory_bits(bitmap, sec, 1);
                 bitmap_file_set_bit(bitmap, sec);
+                if (sec < bitmap->mddev->recovery_cp)
+                        /* We are asserting that the array is dirty,
+                         * so move the recovery_cp address back so
+                         * that it is obvious that it is dirty
+                         */
+                        bitmap->mddev->recovery_cp = sec;
         }
 }
 
@@ -1531,7 +1581,7 @@ void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
 void bitmap_flush(mddev_t *mddev)
 {
         struct bitmap *bitmap = mddev->bitmap;
-        int sleep;
+        long sleep;
 
         if (!bitmap) /* there was no bitmap */
                 return;
@@ -1539,12 +1589,13 @@ void bitmap_flush(mddev_t *mddev)
         /* run the daemon_work three time to ensure everything is flushed
          * that can be
          */
-        sleep = bitmap->daemon_sleep;
-        bitmap->daemon_sleep = 0;
-        bitmap_daemon_work(bitmap);
-        bitmap_daemon_work(bitmap);
-        bitmap_daemon_work(bitmap);
-        bitmap->daemon_sleep = sleep;
+        sleep = mddev->bitmap_info.daemon_sleep * 2;
+        bitmap->daemon_lastrun -= sleep;
+        bitmap_daemon_work(mddev);
+        bitmap->daemon_lastrun -= sleep;
+        bitmap_daemon_work(mddev);
+        bitmap->daemon_lastrun -= sleep;
+        bitmap_daemon_work(mddev);
         bitmap_update_sb(bitmap);
 }
 
@@ -1574,6 +1625,7 @@ static void bitmap_free(struct bitmap *bitmap)
         kfree(bp);
         kfree(bitmap);
 }
+
 void bitmap_destroy(mddev_t *mddev)
 {
         struct bitmap *bitmap = mddev->bitmap;
@@ -1581,10 +1633,15 @@ void bitmap_destroy(mddev_t *mddev)
         if (!bitmap) /* there was no bitmap */
                 return;
 
+        mutex_lock(&mddev->bitmap_info.mutex);
         mddev->bitmap = NULL; /* disconnect from the md device */
+        mutex_unlock(&mddev->bitmap_info.mutex);
         if (mddev->thread)
                 mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
 
+        if (bitmap->sysfs_can_clear)
+                sysfs_put(bitmap->sysfs_can_clear);
+
         bitmap_free(bitmap);
 }
 
@@ -1598,16 +1655,17 @@ int bitmap_create(mddev_t *mddev)
         sector_t blocks = mddev->resync_max_sectors;
         unsigned long chunks;
         unsigned long pages;
-        struct file *file = mddev->bitmap_file;
+        struct file *file = mddev->bitmap_info.file;
         int err;
         sector_t start;
+        struct sysfs_dirent *bm;
 
         BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
 
-        if (!file && !mddev->bitmap_offset) /* bitmap disabled, nothing to do */
+        if (!file && !mddev->bitmap_info.offset) /* bitmap disabled, nothing to do */
                 return 0;
 
-        BUG_ON(file && mddev->bitmap_offset);
+        BUG_ON(file && mddev->bitmap_info.offset);
 
         bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
         if (!bitmap)
@@ -1620,8 +1678,14 @@ int bitmap_create(mddev_t *mddev)
 
         bitmap->mddev = mddev;
 
+        bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
+        if (bm) {
+                bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
+                sysfs_put(bm);
+        } else
+                bitmap->sysfs_can_clear = NULL;
+
         bitmap->file = file;
-        bitmap->offset = mddev->bitmap_offset;
         if (file) {
                 get_file(file);
                 /* As future accesses to this file will use bmap,
@@ -1630,12 +1694,22 @@ int bitmap_create(mddev_t *mddev)
                  */
                 vfs_fsync(file, file->f_dentry, 1);
         }
-        /* read superblock from bitmap file (this sets bitmap->chunksize) */
-        err = bitmap_read_sb(bitmap);
+        /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
+        if (!mddev->bitmap_info.external)
+                err = bitmap_read_sb(bitmap);
+        else {
+                err = 0;
+                if (mddev->bitmap_info.chunksize == 0 ||
+                    mddev->bitmap_info.daemon_sleep == 0)
+                        /* chunksize and time_base need to be
+                         * set first. */
+                        err = -EINVAL;
+        }
         if (err)
                 goto error;
 
-        bitmap->chunkshift = ffz(~bitmap->chunksize);
+        bitmap->daemon_lastrun = jiffies;
+        bitmap->chunkshift = ffz(~mddev->bitmap_info.chunksize);
 
         /* now that chunksize and chunkshift are set, we can use these macros */
         chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) >>
@@ -1677,7 +1751,8 @@ int bitmap_create(mddev_t *mddev)
 
         mddev->bitmap = bitmap;
 
-        mddev->thread->timeout = bitmap->daemon_sleep * HZ;
+        mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
+        md_wakeup_thread(mddev->thread);
 
         bitmap_update_sb(bitmap);
 
@@ -1688,6 +1763,264 @@ 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->bitmap_info.external == 0 &&
+                            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 ssize_t metadata_show(mddev_t *mddev, char *page)
+{
+        return sprintf(page, "%s\n", (mddev->bitmap_info.external
+                                      ? "external" : "internal"));
+}
+
+static ssize_t metadata_store(mddev_t *mddev, const char *buf, size_t len)
+{
+        if (mddev->bitmap ||
+            mddev->bitmap_info.file ||
+            mddev->bitmap_info.offset)
+                return -EBUSY;
+        if (strncmp(buf, "external", 8) == 0)
+                mddev->bitmap_info.external = 1;
+        else if (strncmp(buf, "internal", 8) == 0)
+                mddev->bitmap_info.external = 0;
+        else
+                return -EINVAL;
+        return len;
+}
+
+static struct md_sysfs_entry bitmap_metadata =
+__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
+
+static ssize_t can_clear_show(mddev_t *mddev, char *page)
+{
+        int len;
+        if (mddev->bitmap)
+                len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
+                                             "false" : "true"));
+        else
+                len = sprintf(page, "\n");
+        return len;
+}
+
+static ssize_t can_clear_store(mddev_t *mddev, const char *buf, size_t len)
+{
+        if (mddev->bitmap == NULL)
+                return -ENOENT;
+        if (strncmp(buf, "false", 5) == 0)
+                mddev->bitmap->need_sync = 1;
+        else if (strncmp(buf, "true", 4) == 0) {
+                if (mddev->degraded)
+                        return -EBUSY;
+                mddev->bitmap->need_sync = 0;
+        } else
+                return -EINVAL;
+        return len;
+}
+
+static struct md_sysfs_entry bitmap_can_clear =
+__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
+
+static struct attribute *md_bitmap_attrs[] = {
+        &bitmap_location.attr,
+        &bitmap_timeout.attr,
+        &bitmap_backlog.attr,
+        &bitmap_chunksize.attr,
+        &bitmap_metadata.attr,
+        &bitmap_can_clear.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);
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index e98900671ca9..cb821d76d1b4 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -106,7 +106,7 @@ typedef __u16 bitmap_counter_t;
 #define BITMAP_BLOCK_SHIFT 9
 
 /* how many blocks per chunk? (this is variable) */
-#define CHUNK_BLOCK_RATIO(bitmap) ((bitmap)->chunksize >> BITMAP_BLOCK_SHIFT)
+#define CHUNK_BLOCK_RATIO(bitmap) ((bitmap)->mddev->bitmap_info.chunksize >> BITMAP_BLOCK_SHIFT)
 #define CHUNK_BLOCK_SHIFT(bitmap) ((bitmap)->chunkshift - BITMAP_BLOCK_SHIFT)
 #define CHUNK_BLOCK_MASK(bitmap) (CHUNK_BLOCK_RATIO(bitmap) - 1)
 
@@ -118,16 +118,6 @@ typedef __u16 bitmap_counter_t;
                         (CHUNK_BLOCK_SHIFT(bitmap) + PAGE_COUNTER_SHIFT - 1)
 #define PAGEPTR_BLOCK_MASK(bitmap) (PAGEPTR_BLOCK_RATIO(bitmap) - 1)
 
-/*
- * on-disk bitmap:
- *
- * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
- * file a page at a time. There's a superblock at the start of the file.
- */
-
-/* map chunks (bits) to file pages - offset by the size of the superblock */
-#define CHUNK_BIT_OFFSET(chunk) ((chunk) + (sizeof(bitmap_super_t) << 3))
-
 #endif
 
 /*
@@ -209,7 +199,6 @@ struct bitmap {
         int counter_bits; /* how many bits per block counter */
 
         /* bitmap chunksize -- how much data does each bit represent? */
-        unsigned long chunksize;
         unsigned long chunkshift; /* chunksize = 2^chunkshift (for bitops) */
         unsigned long chunks; /* total number of data chunks for the array */
 
@@ -226,7 +215,6 @@ struct bitmap {
         /* bitmap spinlock */
         spinlock_t lock;
 
-        long offset; /* offset from superblock if file is NULL */
         struct file *file; /* backing disk file */
         struct page *sb_page; /* cached copy of the bitmap file superblock */
         struct page **filemap; /* list of cache pages for the file */
@@ -238,7 +226,6 @@ struct bitmap {
 
         int allclean;
 
-        unsigned long max_write_behind; /* write-behind mode */
         atomic_t behind_writes;
 
         /*
@@ -246,7 +233,6 @@ struct bitmap {
          * file, cleaning up bits and flushing out pages to disk as necessary
          */
         unsigned long daemon_lastrun; /* jiffies of last run */
-        unsigned long daemon_sleep; /* how many seconds between updates? */
         unsigned long last_end_sync; /* when we lasted called end_sync to
                                       * update bitmap with resync progress */
 
@@ -254,6 +240,7 @@ struct bitmap {
         wait_queue_head_t write_wait;
         wait_queue_head_t overflow_wait;
 
+        struct sysfs_dirent *sysfs_can_clear;
 };
 
 /* the bitmap API */
@@ -282,7 +269,7 @@ void bitmap_close_sync(struct bitmap *bitmap);
 void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector);
 
 void bitmap_unplug(struct bitmap *bitmap);
-void bitmap_daemon_work(struct bitmap *bitmap);
+void bitmap_daemon_work(mddev_t *mddev);
 #endif
 
 #endif
diff --git a/drivers/md/faulty.c b/drivers/md/faulty.c
index 87d88dbb667f..713acd02ab39 100644
--- a/drivers/md/faulty.c
+++ b/drivers/md/faulty.c
@@ -360,6 +360,7 @@ static void raid_exit(void)
 module_init(raid_init);
 module_exit(raid_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Fault injection personality for MD");
 MODULE_ALIAS("md-personality-10"); /* faulty */
 MODULE_ALIAS("md-faulty");
 MODULE_ALIAS("md-level--5");
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 1ceceb334d5e..00435bd20699 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -292,7 +292,7 @@ static int linear_make_request (struct request_queue *q, struct bio *bio)
         int cpu;
 
         if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) {
-                bio_endio(bio, -EOPNOTSUPP);
+                md_barrier_request(mddev, bio);
                 return 0;
         }
 
@@ -383,6 +383,7 @@ static void linear_exit (void)
 module_init(linear_init);
 module_exit(linear_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Linear device concatenation personality for MD");
 MODULE_ALIAS("md-personality-1"); /* LINEAR - deprecated*/
 MODULE_ALIAS("md-linear");
 MODULE_ALIAS("md-level--1");
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5f154ef1e4be..e1f3c1715cca 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -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)
 {
@@ -363,6 +470,7 @@ static mddev_t * mddev_find(dev_t unit)
 
         mutex_init(&new->open_mutex);
         mutex_init(&new->reconfig_mutex);
+        mutex_init(&new->bitmap_info.mutex);
         INIT_LIST_HEAD(&new->disks);
         INIT_LIST_HEAD(&new->all_mddevs);
         init_timer(&new->safemode_timer);
@@ -370,6 +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;
@@ -748,7 +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);
@@ -876,8 +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;
@@ -911,8 +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 */
@@ -1029,7 +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);
@@ -1107,7 +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)
@@ -1286,8 +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);
@@ -1295,8 +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);
@@ -1390,19 +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) {
@@ -1436,7 +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);
@@ -1458,7 +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 {
@@ -2442,12 +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
@@ -2549,6 +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);
@@ -2659,6 +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
@@ -2670,31 +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))
-                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)
+        if (strict_strtoul_scaled(cbuf, &msec, 3) < 0)
                 return -EINVAL;
-        msec = (msec * 1000) / scale;
         if (msec == 0)
                 mddev->safemode_delay = 0;
         else {
@@ -2970,7 +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;
@@ -3166,6 +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;
@@ -3790,6 +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,
 };
 
@@ -3894,6 +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);
 }
@@ -3985,6 +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) {
@@ -4206,6 +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;
@@ -4310,7 +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;
 
@@ -4405,12 +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();
@@ -4451,6 +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;
@@ -4636,7 +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;
@@ -4994,23 +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;
@@ -5025,11 +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;
@@ -5096,8 +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;
 
@@ -5197,7 +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 ||
@@ -5256,9 +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)
@@ -5273,7 +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);
@@ -5524,6 +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)
 {
@@ -5589,6 +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,
@@ -5982,14 +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: ");
@@ -6338,12 +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));
@@ -6380,6 +6609,7 @@ void md_do_sync(mddev_t *mddev)
                        desc, mdname(mddev));
                 mddev->curr_resync = j;
         }
+        mddev->curr_resync_completed = mddev->curr_resync;
 
         while (j < max_sectors) {
                 sector_t sectors;
@@ -6512,22 +6742,29 @@ 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);
 
  skip:
+        if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
+                /* We completed so min/max setting can be forgotten if used. */
+                if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+                        mddev->resync_min = 0;
+                mddev->resync_max = MaxSector;
+        } else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+                mddev->resync_min = mddev->curr_resync_completed;
         mddev->curr_resync = 0;
-        mddev->curr_resync_completed = 0;
         if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
-                /* We completed so max setting can be forgotten. */
-                mddev->resync_max = MaxSector;
+                mddev->curr_resync_completed = 0;
         sysfs_notify(&mddev->kobj, NULL, "sync_completed");
         wake_up(&resync_wait);
         set_bit(MD_RECOVERY_DONE, &mddev->recovery);
@@ -6590,6 +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;
                         }
@@ -6625,7 +6863,7 @@ void md_check_recovery(mddev_t *mddev)
 
 
         if (mddev->bitmap)
-                bitmap_daemon_work(mddev->bitmap);
+                bitmap_daemon_work(mddev);
 
         if (mddev->ro)
                 return;
@@ -6995,5 +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);
diff --git a/drivers/md/md.h b/drivers/md/md.h
index f184b69ef337..8e4c75c00d46 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -97,6 +97,9 @@ struct mdk_rdev_s
         atomic_t        read_errors;    /* number of consecutive read errors that
                                          * we have tried to ignore.
                                          */
+        struct timespec last_read_error;        /* monotonic time since our
+                                                 * last read error
+                                                 */
         atomic_t        corrected_errors; /* number of corrected read errors,
                                            * for reporting to userspace and storing
                                            * in superblock.
@@ -280,17 +283,38 @@ struct mddev_s
         unsigned int                    max_write_behind; /* 0 = sync */
 
         struct bitmap                   *bitmap; /* the bitmap for the device */
-        struct file                     *bitmap_file; /* the bitmap file */
-        long                            bitmap_offset; /* offset from superblock of
-                                                        * start of bitmap. May be
-                                                        * negative, but not '0'
-                                                        */
-        long                            default_bitmap_offset; /* this is the offset to use when
-                                                                * hot-adding a bitmap.  It should
-                                                                * eventually be settable by sysfs.
-                                                                */
-
+        struct {
+                struct file             *file; /* the bitmap file */
+                loff_t                  offset; /* offset from superblock of
+                                                 * start of bitmap. May be
+                                                 * negative, but not '0'
+                                                 * For external metadata, offset
+                                                 * from start of device. 
+                                                 */
+                loff_t                  default_offset; /* this is the offset to use when
+                                                         * hot-adding a bitmap.  It should
+                                                         * eventually be settable by sysfs.
+                                                         */
+                struct mutex            mutex;
+                unsigned long           chunksize;
+                unsigned long           daemon_sleep; /* how many seconds between updates? */
+                unsigned long           max_write_behind; /* write-behind mode */
+                int                     external;
+        } bitmap_info;
+
+        atomic_t                        max_corr_read_errors; /* max read retries */
         struct list_head                all_mddevs;
+
+        /* Generic barrier handling.
+         * If there is a pending barrier request, all other
+         * writes are blocked while the devices are flushed.
+         * The last to finish a flush schedules a worker to
+         * submit the barrier request (without the barrier flag),
+         * then submit more flush requests.
+         */
+        struct bio *barrier;
+        atomic_t flush_pending;
+        struct work_struct barrier_work;
 };
 
 
@@ -353,7 +377,7 @@ struct md_sysfs_entry {
         ssize_t (*show)(mddev_t *, char *);
         ssize_t (*store)(mddev_t *, const char *, size_t);
 };
-
+extern struct attribute_group md_bitmap_group;
 
 static inline char * mdname (mddev_t * mddev)
 {
@@ -431,6 +455,7 @@ extern void md_done_sync(mddev_t *mddev, int blocks, int ok);
 extern void md_error(mddev_t *mddev, mdk_rdev_t *rdev);
 
 extern int mddev_congested(mddev_t *mddev, int bits);
+extern void md_barrier_request(mddev_t *mddev, struct bio *bio);
 extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
                            sector_t sector, int size, struct page *page);
 extern void md_super_wait(mddev_t *mddev);
@@ -443,6 +468,8 @@ extern void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev);
 extern void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors);
 extern int md_check_no_bitmap(mddev_t *mddev);
 extern int md_integrity_register(mddev_t *mddev);
-void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev);
+extern void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev);
+extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
+extern void restore_bitmap_write_access(struct file *file);
 
 #endif /* _MD_MD_H */
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index ee7646f974a0..32a662fc55c9 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -145,7 +145,7 @@ static int multipath_make_request (struct request_queue *q, struct bio * bio)
         int cpu;
 
         if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) {
-                bio_endio(bio, -EOPNOTSUPP);
+                md_barrier_request(mddev, bio);
                 return 0;
         }
 
@@ -581,6 +581,7 @@ static void __exit multipath_exit (void)
 module_init(multipath_init);
 module_exit(multipath_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("simple multi-path personality for MD");
 MODULE_ALIAS("md-personality-7"); /* MULTIPATH */
 MODULE_ALIAS("md-multipath");
 MODULE_ALIAS("md-level--4");
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index d3a4ce06015a..77605cdceaf1 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -453,7 +453,7 @@ static int raid0_make_request(struct request_queue *q, struct bio *bio)
         int cpu;
 
         if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) {
-                bio_endio(bio, -EOPNOTSUPP);
+                md_barrier_request(mddev, bio);
                 return 0;
         }
 
@@ -567,6 +567,7 @@ static void raid0_exit (void)
 module_init(raid0_init);
 module_exit(raid0_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
 MODULE_ALIAS("md-personality-2"); /* RAID0 */
 MODULE_ALIAS("md-raid0");
 MODULE_ALIAS("md-level-0");
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index e07ce2e033a9..859bd3ffe435 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -677,6 +677,7 @@ static void raise_barrier(conf_t *conf)
 static void lower_barrier(conf_t *conf)
 {
         unsigned long flags;
+        BUG_ON(conf->barrier <= 0);
         spin_lock_irqsave(&conf->resync_lock, flags);
         conf->barrier--;
         spin_unlock_irqrestore(&conf->resync_lock, flags);
@@ -801,6 +802,25 @@ static int make_request(struct request_queue *q, struct bio * bio)
 
         md_write_start(mddev, bio); /* wait on superblock update early */
 
+        if (bio_data_dir(bio) == WRITE &&
+            bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
+            bio->bi_sector < mddev->suspend_hi) {
+                /* As the suspend_* range is controlled by
+                 * userspace, we want an interruptible
+                 * wait.
+                 */
+                DEFINE_WAIT(w);
+                for (;;) {
+                        flush_signals(current);
+                        prepare_to_wait(&conf->wait_barrier,
+                                        &w, TASK_INTERRUPTIBLE);
+                        if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
+                            bio->bi_sector >= mddev->suspend_hi)
+                                break;
+                        schedule();
+                }
+                finish_wait(&conf->wait_barrier, &w);
+        }
         if (unlikely(!mddev->barriers_work &&
                      bio_rw_flagged(bio, BIO_RW_BARRIER))) {
                 if (rw == WRITE)
@@ -923,7 +943,8 @@ static int make_request(struct request_queue *q, struct bio * bio)
 
         /* do behind I/O ? */
         if (bitmap &&
-            atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind &&
+            (atomic_read(&bitmap->behind_writes)
+             < mddev->bitmap_info.max_write_behind) &&
             (behind_pages = alloc_behind_pages(bio)) != NULL)
                 set_bit(R1BIO_BehindIO, &r1_bio->state);
 
@@ -1941,74 +1962,48 @@ static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks)
         return mddev->dev_sectors;
 }
 
-static int run(mddev_t *mddev)
+static conf_t *setup_conf(mddev_t *mddev)
 {
         conf_t *conf;
-        int i, j, disk_idx;
+        int i;
         mirror_info_t *disk;
         mdk_rdev_t *rdev;
+        int err = -ENOMEM;
 
-        if (mddev->level != 1) {
-                printk("raid1: %s: raid level not set to mirroring (%d)\n",
-                       mdname(mddev), mddev->level);
-                goto out;
-        }
-        if (mddev->reshape_position != MaxSector) {
-                printk("raid1: %s: reshape_position set but not supported\n",
-                       mdname(mddev));
-                goto out;
-        }
-        /*
-         * copy the already verified devices into our private RAID1
-         * bookkeeping area. [whatever we allocate in run(),
-         * should be freed in stop()]
-         */
         conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
-        mddev->private = conf;
         if (!conf)
-                goto out_no_mem;
+                goto abort;
 
         conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
                                  GFP_KERNEL);
         if (!conf->mirrors)
-                goto out_no_mem;
+                goto abort;
 
         conf->tmppage = alloc_page(GFP_KERNEL);
         if (!conf->tmppage)
-                goto out_no_mem;
+                goto abort;
 
-        conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
+        conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
         if (!conf->poolinfo)
-                goto out_no_mem;
-        conf->poolinfo->mddev = NULL;
+                goto abort;
         conf->poolinfo->raid_disks = mddev->raid_disks;
         conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
                                           r1bio_pool_free,
                                           conf->poolinfo);
         if (!conf->r1bio_pool)
-                goto out_no_mem;
+                goto abort;
+
         conf->poolinfo->mddev = mddev;
 
         spin_lock_init(&conf->device_lock);
-        mddev->queue->queue_lock = &conf->device_lock;
-
         list_for_each_entry(rdev, &mddev->disks, same_set) {
-                disk_idx = rdev->raid_disk;
+                int disk_idx = rdev->raid_disk;
                 if (disk_idx >= mddev->raid_disks
                     || disk_idx < 0)
                         continue;
                 disk = conf->mirrors + disk_idx;
 
                 disk->rdev = rdev;
-                disk_stack_limits(mddev->gendisk, rdev->bdev,
-                                  rdev->data_offset << 9);
-                /* as we don't honour merge_bvec_fn, we must never risk
-                 * violating it, so limit ->max_sector to one PAGE, as
-                 * a one page request is never in violation.
-                 */
-                if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
-                    queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9))
-                        blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
 
                 disk->head_position = 0;
         }
@@ -2022,8 +2017,7 @@ static int run(mddev_t *mddev)
         bio_list_init(&conf->pending_bio_list);
         bio_list_init(&conf->flushing_bio_list);
 
-
-        mddev->degraded = 0;
+        conf->last_used = -1;
         for (i = 0; i < conf->raid_disks; i++) {
 
                 disk = conf->mirrors + i;
@@ -2031,38 +2025,97 @@ static int run(mddev_t *mddev)
                 if (!disk->rdev ||
                     !test_bit(In_sync, &disk->rdev->flags)) {
                         disk->head_position = 0;
-                        mddev->degraded++;
                         if (disk->rdev)
                                 conf->fullsync = 1;
-                }
+                } else if (conf->last_used < 0)
+                        /*
+                         * The first working device is used as a
+                         * starting point to read balancing.
+                         */
+                        conf->last_used = i;
         }
-        if (mddev->degraded == conf->raid_disks) {
+
+        err = -EIO;
+        if (conf->last_used < 0) {
                 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
-                        mdname(mddev));
-                goto out_free_conf;
+                       mdname(mddev));
+                goto abort;
         }
-        if (conf->raid_disks - mddev->degraded == 1)
-                mddev->recovery_cp = MaxSector;
+        err = -ENOMEM;
+        conf->thread = md_register_thread(raid1d, mddev, NULL);
+        if (!conf->thread) {
+                printk(KERN_ERR
+                       "raid1: couldn't allocate thread for %s\n",
+                       mdname(mddev));
+                goto abort;
+        }
+
+        return conf;
+
+ abort:
+        if (conf) {
+                if (conf->r1bio_pool)
+                        mempool_destroy(conf->r1bio_pool);
+                kfree(conf->mirrors);
+                safe_put_page(conf->tmppage);
+                kfree(conf->poolinfo);
+                kfree(conf);
+        }
+        return ERR_PTR(err);
+}
 
+static int run(mddev_t *mddev)
+{
+        conf_t *conf;
+        int i;
+        mdk_rdev_t *rdev;
+
+        if (mddev->level != 1) {
+                printk("raid1: %s: raid level not set to mirroring (%d)\n",
+                       mdname(mddev), mddev->level);
+                return -EIO;
+        }
+        if (mddev->reshape_position != MaxSector) {
+                printk("raid1: %s: reshape_position set but not supported\n",
+                       mdname(mddev));
+                return -EIO;
+        }
         /*
-         * find the first working one and use it as a starting point
-         * to read balancing.
+         * copy the already verified devices into our private RAID1
+         * bookkeeping area. [whatever we allocate in run(),
+         * should be freed in stop()]
          */
-        for (j = 0; j < conf->raid_disks &&
-                     (!conf->mirrors[j].rdev ||
-                      !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++)
-                /* nothing */;
-        conf->last_used = j;
+        if (mddev->private == NULL)
+                conf = setup_conf(mddev);
+        else
+                conf = mddev->private;
 
+        if (IS_ERR(conf))
+                return PTR_ERR(conf);
 
-        mddev->thread = md_register_thread(raid1d, mddev, NULL);
-        if (!mddev->thread) {
-                printk(KERN_ERR
-                       "raid1: couldn't allocate thread for %s\n",
-                       mdname(mddev));
-                goto out_free_conf;
+        mddev->queue->queue_lock = &conf->device_lock;
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
+                disk_stack_limits(mddev->gendisk, rdev->bdev,
+                                  rdev->data_offset << 9);
+                /* as we don't honour merge_bvec_fn, we must never risk
+                 * violating it, so limit ->max_sector to one PAGE, as
+                 * a one page request is never in violation.
+                 */
+                if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
+                    queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9))
+                        blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
         }
 
+        mddev->degraded = 0;
+        for (i=0; i < conf->raid_disks; i++)
+                if (conf->mirrors[i].rdev == NULL ||
+                    !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
+                    test_bit(Faulty, &conf->mirrors[i].rdev->flags))
+                        mddev->degraded++;
+
+        if (conf->raid_disks - mddev->degraded == 1)
+                mddev->recovery_cp = MaxSector;
+
         if (mddev->recovery_cp != MaxSector)
                 printk(KERN_NOTICE "raid1: %s is not clean"
                        " -- starting background reconstruction\n",
@@ -2071,9 +2124,14 @@ static int run(mddev_t *mddev)
                 "raid1: raid set %s active with %d out of %d mirrors\n",
                 mdname(mddev), mddev->raid_disks - mddev->degraded, 
                 mddev->raid_disks);
+
         /*
          * Ok, everything is just fine now
          */
+        mddev->thread = conf->thread;
+        conf->thread = NULL;
+        mddev->private = conf;
+
         md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
 
         mddev->queue->unplug_fn = raid1_unplug;
@@ -2081,23 +2139,6 @@ static int run(mddev_t *mddev)
         mddev->queue->backing_dev_info.congested_data = mddev;
         md_integrity_register(mddev);
         return 0;
-
-out_no_mem:
-        printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
-               mdname(mddev));
-
-out_free_conf:
-        if (conf) {
-                if (conf->r1bio_pool)
-                        mempool_destroy(conf->r1bio_pool);
-                kfree(conf->mirrors);
-                safe_put_page(conf->tmppage);
-                kfree(conf->poolinfo);
-                kfree(conf);
-                mddev->private = NULL;
-        }
-out:
-        return -EIO;
 }
 
 static int stop(mddev_t *mddev)
@@ -2271,6 +2312,9 @@ static void raid1_quiesce(mddev_t *mddev, int state)
         conf_t *conf = mddev->private;
 
         switch(state) {
+        case 2: /* wake for suspend */
+                wake_up(&conf->wait_barrier);
+                break;
         case 1:
                 raise_barrier(conf);
                 break;
@@ -2280,6 +2324,23 @@ static void raid1_quiesce(mddev_t *mddev, int state)
         }
 }
 
+static void *raid1_takeover(mddev_t *mddev)
+{
+        /* raid1 can take over:
+         *  raid5 with 2 devices, any layout or chunk size
+         */
+        if (mddev->level == 5 && mddev->raid_disks == 2) {
+                conf_t *conf;
+                mddev->new_level = 1;
+                mddev->new_layout = 0;
+                mddev->new_chunk_sectors = 0;
+                conf = setup_conf(mddev);
+                if (!IS_ERR(conf))
+                        conf->barrier = 1;
+                return conf;
+        }
+        return ERR_PTR(-EINVAL);
+}
 
 static struct mdk_personality raid1_personality =
 {
@@ -2299,6 +2360,7 @@ static struct mdk_personality raid1_personality =
         .size           = raid1_size,
         .check_reshape  = raid1_reshape,
         .quiesce        = raid1_quiesce,
+        .takeover       = raid1_takeover,
 };
 
 static int __init raid_init(void)
@@ -2314,6 +2376,7 @@ static void raid_exit(void)
 module_init(raid_init);
 module_exit(raid_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
 MODULE_ALIAS("md-personality-3"); /* RAID1 */
 MODULE_ALIAS("md-raid1");
 MODULE_ALIAS("md-level-1");
diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h
index e87b84deff68..5f2d443ae28a 100644
--- a/drivers/md/raid1.h
+++ b/drivers/md/raid1.h
@@ -59,6 +59,11 @@ struct r1_private_data_s {
 
         mempool_t *r1bio_pool;
         mempool_t *r1buf_pool;
+
+        /* When taking over an array from a different personality, we store
+         * the new thread here until we fully activate the array.
+         */
+        struct mdk_thread_s     *thread;
 };
 
 typedef struct r1_private_data_s conf_t;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index c2cb7b87b440..d119b7b75e71 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -804,7 +804,7 @@ static int make_request(struct request_queue *q, struct bio * bio)
         mdk_rdev_t *blocked_rdev;
 
         if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) {
-                bio_endio(bio, -EOPNOTSUPP);
+                md_barrier_request(mddev, bio);
                 return 0;
         }
 
@@ -1432,6 +1432,43 @@ static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
 
 
 /*
+ * Used by fix_read_error() to decay the per rdev read_errors.
+ * We halve the read error count for every hour that has elapsed
+ * since the last recorded read error.
+ *
+ */
+static void check_decay_read_errors(mddev_t *mddev, mdk_rdev_t *rdev)
+{
+        struct timespec cur_time_mon;
+        unsigned long hours_since_last;
+        unsigned int read_errors = atomic_read(&rdev->read_errors);
+
+        ktime_get_ts(&cur_time_mon);
+
+        if (rdev->last_read_error.tv_sec == 0 &&
+            rdev->last_read_error.tv_nsec == 0) {
+                /* first time we've seen a read error */
+                rdev->last_read_error = cur_time_mon;
+                return;
+        }
+
+        hours_since_last = (cur_time_mon.tv_sec -
+                            rdev->last_read_error.tv_sec) / 3600;
+
+        rdev->last_read_error = cur_time_mon;
+
+        /*
+         * if hours_since_last is > the number of bits in read_errors
+         * just set read errors to 0. We do this to avoid
+         * overflowing the shift of read_errors by hours_since_last.
+         */
+        if (hours_since_last >= 8 * sizeof(read_errors))
+                atomic_set(&rdev->read_errors, 0);
+        else
+                atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
+}
+
+/*
  * This is a kernel thread which:
  *
  *      1.      Retries failed read operations on working mirrors.
@@ -1444,6 +1481,43 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
         int sect = 0; /* Offset from r10_bio->sector */
         int sectors = r10_bio->sectors;
         mdk_rdev_t*rdev;
+        int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
+
+        rcu_read_lock();
+        {
+                int d = r10_bio->devs[r10_bio->read_slot].devnum;
+                char b[BDEVNAME_SIZE];
+                int cur_read_error_count = 0;
+
+                rdev = rcu_dereference(conf->mirrors[d].rdev);
+                bdevname(rdev->bdev, b);
+
+                if (test_bit(Faulty, &rdev->flags)) {
+                        rcu_read_unlock();
+                        /* drive has already been failed, just ignore any
+                           more fix_read_error() attempts */
+                        return;
+                }
+
+                check_decay_read_errors(mddev, rdev);
+                atomic_inc(&rdev->read_errors);
+                cur_read_error_count = atomic_read(&rdev->read_errors);
+                if (cur_read_error_count > max_read_errors) {
+                        rcu_read_unlock();
+                        printk(KERN_NOTICE
+                               "raid10: %s: Raid device exceeded "
+                               "read_error threshold "
+                               "[cur %d:max %d]\n",
+                               b, cur_read_error_count, max_read_errors);
+                        printk(KERN_NOTICE
+                               "raid10: %s: Failing raid "
+                               "device\n", b);
+                        md_error(mddev, conf->mirrors[d].rdev);
+                        return;
+                }
+        }
+        rcu_read_unlock();
+
         while(sectors) {
                 int s = sectors;
                 int sl = r10_bio->read_slot;
@@ -1488,6 +1562,7 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                 /* write it back and re-read */
                 rcu_read_lock();
                 while (sl != r10_bio->read_slot) {
+                        char b[BDEVNAME_SIZE];
                         int d;
                         if (sl==0)
                                 sl = conf->copies;
@@ -1503,9 +1578,21 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                                                  r10_bio->devs[sl].addr +
                                                  sect + rdev->data_offset,
                                                  s<<9, conf->tmppage, WRITE)
-                                    == 0)
+                                    == 0) {
                                         /* Well, this device is dead */
+                                        printk(KERN_NOTICE
+                                               "raid10:%s: read correction "
+                                               "write failed"
+                                               " (%d sectors at %llu on %s)\n",
+                                               mdname(mddev), s,
+                                               (unsigned long long)(sect+
+                                               rdev->data_offset),
+                                               bdevname(rdev->bdev, b));
+                                        printk(KERN_NOTICE "raid10:%s: failing "
+                                               "drive\n",
+                                               bdevname(rdev->bdev, b));
                                         md_error(mddev, rdev);
+                                }
                                 rdev_dec_pending(rdev, mddev);
                                 rcu_read_lock();
                         }
@@ -1526,10 +1613,22 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                                 if (sync_page_io(rdev->bdev,
                                                  r10_bio->devs[sl].addr +
                                                  sect + rdev->data_offset,
-                                                 s<<9, conf->tmppage, READ) == 0)
+                                                 s<<9, conf->tmppage,
+                                                 READ) == 0) {
                                         /* Well, this device is dead */
+                                        printk(KERN_NOTICE
+                                               "raid10:%s: unable to read back "
+                                               "corrected sectors"
+                                               " (%d sectors at %llu on %s)\n",
+                                               mdname(mddev), s,
+                                               (unsigned long long)(sect+
+                                                    rdev->data_offset),
+                                               bdevname(rdev->bdev, b));
+                                        printk(KERN_NOTICE "raid10:%s: failing drive\n",
+                                               bdevname(rdev->bdev, b));
+
                                         md_error(mddev, rdev);
-                                else
+                                } else {
                                         printk(KERN_INFO
                                                "raid10:%s: read error corrected"
                                                " (%d sectors at %llu on %s)\n",
@@ -1537,6 +1636,7 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                                                (unsigned long long)(sect+
                                                     rdev->data_offset),
                                                bdevname(rdev->bdev, b));
+                                }
 
                                 rdev_dec_pending(rdev, mddev);
                                 rcu_read_lock();
@@ -2275,13 +2375,6 @@ static void raid10_quiesce(mddev_t *mddev, int state)
                 lower_barrier(conf);
                 break;
         }
-        if (mddev->thread) {
-                if (mddev->bitmap)
-                        mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ;
-                else
-                        mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
-                md_wakeup_thread(mddev->thread);
-        }
 }
 
 static struct mdk_personality raid10_personality =
@@ -2315,6 +2408,7 @@ static void raid_exit(void)
 module_init(raid_init);
 module_exit(raid_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
 MODULE_ALIAS("md-personality-9"); /* RAID10 */
 MODULE_ALIAS("md-raid10");
 MODULE_ALIAS("md-level-10");
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index d29215d966da..e84204eb12df 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2947,6 +2947,7 @@ static void handle_stripe5(struct stripe_head *sh)
         struct r5dev *dev;
         mdk_rdev_t *blocked_rdev = NULL;
         int prexor;
+        int dec_preread_active = 0;
 
         memset(&s, 0, sizeof(s));
         pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d check:%d "
@@ -3096,12 +3097,8 @@ static void handle_stripe5(struct stripe_head *sh)
                                         set_bit(STRIPE_INSYNC, &sh->state);
                         }
                 }
-                if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
-                        atomic_dec(&conf->preread_active_stripes);
-                        if (atomic_read(&conf->preread_active_stripes) <
-                                IO_THRESHOLD)
-                                md_wakeup_thread(conf->mddev->thread);
-                }
+                if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
+                        dec_preread_active = 1;
         }
 
         /* Now to consider new write requests and what else, if anything
@@ -3208,6 +3205,16 @@ static void handle_stripe5(struct stripe_head *sh)
 
         ops_run_io(sh, &s);
 
+        if (dec_preread_active) {
+                /* We delay this until after ops_run_io so that if make_request
+                 * is waiting on a barrier, it won't continue until the writes
+                 * have actually been submitted.
+                 */
+                atomic_dec(&conf->preread_active_stripes);
+                if (atomic_read(&conf->preread_active_stripes) <
+                    IO_THRESHOLD)
+                        md_wakeup_thread(conf->mddev->thread);
+        }
         return_io(return_bi);
 }
 
@@ -3221,6 +3228,7 @@ static void handle_stripe6(struct stripe_head *sh)
         struct r6_state r6s;
         struct r5dev *dev, *pdev, *qdev;
         mdk_rdev_t *blocked_rdev = NULL;
+        int dec_preread_active = 0;
 
         pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
                 "pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
@@ -3358,7 +3366,6 @@ static void handle_stripe6(struct stripe_head *sh)
          * completed
          */
         if (sh->reconstruct_state == reconstruct_state_drain_result) {
-                int qd_idx = sh->qd_idx;
 
                 sh->reconstruct_state = reconstruct_state_idle;
                 /* All the 'written' buffers and the parity blocks are ready to
@@ -3380,12 +3387,8 @@ static void handle_stripe6(struct stripe_head *sh)
                                         set_bit(STRIPE_INSYNC, &sh->state);
                         }
                 }
-                if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
-                        atomic_dec(&conf->preread_active_stripes);
-                        if (atomic_read(&conf->preread_active_stripes) <
-                                IO_THRESHOLD)
-                                md_wakeup_thread(conf->mddev->thread);
-                }
+                if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
+                        dec_preread_active = 1;
         }
 
         /* Now to consider new write requests and what else, if anything
@@ -3494,6 +3497,18 @@ static void handle_stripe6(struct stripe_head *sh)
 
         ops_run_io(sh, &s);
 
+
+        if (dec_preread_active) {
+                /* We delay this until after ops_run_io so that if make_request
+                 * is waiting on a barrier, it won't continue until the writes
+                 * have actually been submitted.
+                 */
+                atomic_dec(&conf->preread_active_stripes);
+                if (atomic_read(&conf->preread_active_stripes) <
+                    IO_THRESHOLD)
+                        md_wakeup_thread(conf->mddev->thread);
+        }
+
         return_io(return_bi);
 }
 
@@ -3741,7 +3756,7 @@ static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio)
 {
         mddev_t *mddev = q->queuedata;
         raid5_conf_t *conf = mddev->private;
-        unsigned int dd_idx;
+        int dd_idx;
         struct bio* align_bi;
         mdk_rdev_t *rdev;
 
@@ -3866,7 +3881,13 @@ static int make_request(struct request_queue *q, struct bio * bi)
         int cpu, remaining;
 
         if (unlikely(bio_rw_flagged(bi, BIO_RW_BARRIER))) {
-                bio_endio(bi, -EOPNOTSUPP);
+                /* Drain all pending writes.  We only really need
+                 * to ensure they have been submitted, but this is
+                 * easier.
+                 */
+                mddev->pers->quiesce(mddev, 1);
+                mddev->pers->quiesce(mddev, 0);
+                md_barrier_request(mddev, bi);
                 return 0;
         }
 
@@ -3990,6 +4011,9 @@ static int make_request(struct request_queue *q, struct bio * bi)
                         finish_wait(&conf->wait_for_overlap, &w);
                         set_bit(STRIPE_HANDLE, &sh->state);
                         clear_bit(STRIPE_DELAYED, &sh->state);
+                        if (mddev->barrier && 
+                            !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
+                                atomic_inc(&conf->preread_active_stripes);
                         release_stripe(sh);
                 } else {
                         /* cannot get stripe for read-ahead, just give-up */
@@ -4009,6 +4033,14 @@ static int make_request(struct request_queue *q, struct bio * bi)
 
                 bio_endio(bi, 0);
         }
+
+        if (mddev->barrier) {
+                /* We need to wait for the stripes to all be handled.
+                 * So: wait for preread_active_stripes to drop to 0.
+                 */
+                wait_event(mddev->thread->wqueue,
+                           atomic_read(&conf->preread_active_stripes) == 0);
+        }
         return 0;
 }
 
@@ -5860,6 +5892,7 @@ static void raid5_exit(void)
 module_init(raid5_init);
 module_exit(raid5_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
 MODULE_ALIAS("md-personality-4"); /* RAID5 */
 MODULE_ALIAS("md-raid5");
 MODULE_ALIAS("md-raid4");
diff --git a/drivers/md/raid6algos.c b/drivers/md/raid6algos.c
index 866215ac7f25..bffc61bff5ab 100644
--- a/drivers/md/raid6algos.c
+++ b/drivers/md/raid6algos.c
@@ -31,25 +31,6 @@ EXPORT_SYMBOL(raid6_empty_zero_page);
 struct raid6_calls raid6_call;
 EXPORT_SYMBOL_GPL(raid6_call);
 
-/* Various routine sets */
-extern const struct raid6_calls raid6_intx1;
-extern const struct raid6_calls raid6_intx2;
-extern const struct raid6_calls raid6_intx4;
-extern const struct raid6_calls raid6_intx8;
-extern const struct raid6_calls raid6_intx16;
-extern const struct raid6_calls raid6_intx32;
-extern const struct raid6_calls raid6_mmxx1;
-extern const struct raid6_calls raid6_mmxx2;
-extern const struct raid6_calls raid6_sse1x1;
-extern const struct raid6_calls raid6_sse1x2;
-extern const struct raid6_calls raid6_sse2x1;
-extern const struct raid6_calls raid6_sse2x2;
-extern const struct raid6_calls raid6_sse2x4;
-extern const struct raid6_calls raid6_altivec1;
-extern const struct raid6_calls raid6_altivec2;
-extern const struct raid6_calls raid6_altivec4;
-extern const struct raid6_calls raid6_altivec8;
-
 const struct raid6_calls * const raid6_algos[] = {
         &raid6_intx1,
         &raid6_intx2,
@@ -169,3 +150,4 @@ static void raid6_exit(void)
 subsys_initcall(raid6_select_algo);
 module_exit(raid6_exit);
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID6 Q-syndrome calculations");
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 278020d2449c..14cbc831422a 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -979,24 +979,6 @@ COMPATIBLE_IOCTL(FIGETBSZ)
 /* 'X' - originally XFS but some now in the VFS */
 COMPATIBLE_IOCTL(FIFREEZE)
 COMPATIBLE_IOCTL(FITHAW)
-/* RAID */
-COMPATIBLE_IOCTL(RAID_VERSION)
-COMPATIBLE_IOCTL(GET_ARRAY_INFO)
-COMPATIBLE_IOCTL(GET_DISK_INFO)
-COMPATIBLE_IOCTL(PRINT_RAID_DEBUG)
-COMPATIBLE_IOCTL(RAID_AUTORUN)
-COMPATIBLE_IOCTL(CLEAR_ARRAY)
-COMPATIBLE_IOCTL(ADD_NEW_DISK)
-COMPATIBLE_IOCTL(SET_ARRAY_INFO)
-COMPATIBLE_IOCTL(SET_DISK_INFO)
-COMPATIBLE_IOCTL(WRITE_RAID_INFO)
-COMPATIBLE_IOCTL(UNPROTECT_ARRAY)
-COMPATIBLE_IOCTL(PROTECT_ARRAY)
-COMPATIBLE_IOCTL(RUN_ARRAY)
-COMPATIBLE_IOCTL(STOP_ARRAY)
-COMPATIBLE_IOCTL(STOP_ARRAY_RO)
-COMPATIBLE_IOCTL(RESTART_ARRAY_RW)
-COMPATIBLE_IOCTL(GET_BITMAP_FILE)
 COMPATIBLE_IOCTL(KDGETKEYCODE)
 COMPATIBLE_IOCTL(KDSETKEYCODE)
 COMPATIBLE_IOCTL(KDGKBTYPE)
diff --git a/include/linux/raid/pq.h b/include/linux/raid/pq.h
index d92480f8285c..1cbbd2c11aa9 100644
--- a/include/linux/raid/pq.h
+++ b/include/linux/raid/pq.h
@@ -78,6 +78,25 @@ struct raid6_calls {
 /* Selected algorithm */
 extern struct raid6_calls raid6_call;
 
+/* Various routine sets */
+extern const struct raid6_calls raid6_intx1;
+extern const struct raid6_calls raid6_intx2;
+extern const struct raid6_calls raid6_intx4;
+extern const struct raid6_calls raid6_intx8;
+extern const struct raid6_calls raid6_intx16;
+extern const struct raid6_calls raid6_intx32;
+extern const struct raid6_calls raid6_mmxx1;
+extern const struct raid6_calls raid6_mmxx2;
+extern const struct raid6_calls raid6_sse1x1;
+extern const struct raid6_calls raid6_sse1x2;
+extern const struct raid6_calls raid6_sse2x1;
+extern const struct raid6_calls raid6_sse2x2;
+extern const struct raid6_calls raid6_sse2x4;
+extern const struct raid6_calls raid6_altivec1;
+extern const struct raid6_calls raid6_altivec2;
+extern const struct raid6_calls raid6_altivec4;
+extern const struct raid6_calls raid6_altivec8;
+
 /* Algorithm list */
 extern const struct raid6_calls * const raid6_algos[];
 int raid6_select_algo(void);