1 files changed, 87 insertions, 13 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index dc99d95a1b6d..df1230af02cd 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -658,11 +658,14 @@ static unsigned int calc_sb_csum(mdp_super_t * sb)
  */
 
 struct super_type  {
-        char            *name;
-        struct module   *owner;
-        int             (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version);
-        int             (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
-        void            (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
+        char                *name;
+        struct module       *owner;
+        int                 (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev,
+                                          int minor_version);
+        int                 (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
+        void                (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
+        unsigned long long  (*rdev_size_change)(mdk_rdev_t *rdev,
+                                                unsigned long long size);
 };
 
 /*
@@ -1004,6 +1007,27 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 }
 
 /*
+ * rdev_size_change for 0.90.0
+ */
+static unsigned long long
+super_90_rdev_size_change(mdk_rdev_t *rdev, unsigned long long size)
+{
+        if (size && size < rdev->mddev->size)
+                return 0; /* component must fit device */
+        size *= 2; /* convert to sectors */
+        if (rdev->mddev->bitmap_offset)
+                return 0; /* can't move bitmap */
+        rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
+        if (!size || size > rdev->sb_offset*2)
+                size = rdev->sb_offset*2;
+        md_super_write(rdev->mddev, rdev, rdev->sb_offset << 1, rdev->sb_size,
+                       rdev->sb_page);
+        md_super_wait(rdev->mddev);
+        return size/2; /* kB for sysfs */
+}
+
+
+/*
  * version 1 superblock
  */
 
@@ -1328,21 +1352,59 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
         sb->sb_csum = calc_sb_1_csum(sb);
 }
 
+static unsigned long long
+super_1_rdev_size_change(mdk_rdev_t *rdev, unsigned long long size)
+{
+        struct mdp_superblock_1 *sb;
+        unsigned long long max_size;
+        if (size && size < rdev->mddev->size)
+                return 0; /* component must fit device */
+        size *= 2; /* convert to sectors */
+        if (rdev->sb_offset < rdev->data_offset/2) {
+                /* minor versions 1 and 2; superblock before data */
+                max_size = (rdev->bdev->bd_inode->i_size >> 9);
+                max_size -= rdev->data_offset;
+                if (!size || size > max_size)
+                        size = max_size;
+        } else if (rdev->mddev->bitmap_offset) {
+                /* minor version 0 with bitmap we can't move */
+                return 0;
+        } else {
+                /* minor version 0; superblock after data */
+                sector_t sb_offset;
+                sb_offset = (rdev->bdev->bd_inode->i_size >> 9) - 8*2;
+                sb_offset &= ~(sector_t)(4*2 - 1);
+                max_size = rdev->size*2 + sb_offset - rdev->sb_offset*2;
+                if (!size || size > max_size)
+                        size = max_size;
+                rdev->sb_offset = sb_offset/2;
+        }
+        sb = (struct mdp_superblock_1 *) page_address(rdev->sb_page);
+        sb->data_size = cpu_to_le64(size);
+        sb->super_offset = rdev->sb_offset*2;
+        sb->sb_csum = calc_sb_1_csum(sb);
+        md_super_write(rdev->mddev, rdev, rdev->sb_offset << 1, rdev->sb_size,
+                       rdev->sb_page);
+        md_super_wait(rdev->mddev);
+        return size/2; /* kB for sysfs */
+}
 
 static struct super_type super_types[] = {
         [0] = {
                 .name   = "0.90.0",
                 .owner  = THIS_MODULE,
-                .load_super     = super_90_load,
-                .validate_super = super_90_validate,
-                .sync_super     = super_90_sync,
+                .load_super         = super_90_load,
+                .validate_super     = super_90_validate,
+                .sync_super         = super_90_sync,
+                .rdev_size_change   = super_90_rdev_size_change,
         },
         [1] = {
                 .name   = "md-1",
                 .owner  = THIS_MODULE,
-                .load_super     = super_1_load,
-                .validate_super = super_1_validate,
-                .sync_super     = super_1_sync,
+                .load_super         = super_1_load,
+                .validate_super     = super_1_validate,
+                .sync_super         = super_1_sync,
+                .rdev_size_change   = super_1_rdev_size_change,
         },
 };
 
@@ -2060,8 +2122,20 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
 
         if (e==buf || (*e && *e != '\n'))
                 return -EINVAL;
-        if (my_mddev->pers && rdev->raid_disk >= 0)
-                return -EBUSY;
+        if (my_mddev->pers && rdev->raid_disk >= 0) {
+                if (rdev->mddev->persistent) {
+                        size = super_types[rdev->mddev->major_version].
+                                rdev_size_change(rdev, size);
+                        if (!size)
+                                return -EBUSY;
+                } else if (!size) {
+                        size = (rdev->bdev->bd_inode->i_size >> 10);
+                        size -= rdev->data_offset/2;
+                }
+                if (size < rdev->mddev->size)
+                        return -EINVAL; /* component must fit device */
+        }
+
         rdev->size = size;
         if (size > oldsize && rdev->mddev->external) {
                 /* need to check that all other rdevs with the same ->bdev