Btrfs: Add balance ioctl to restripe the chunks

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 89 insertions, 17 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fe4fe709c312..95aee5a29375 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -17,6 +17,7 @@
  */
 #include <linux/sched.h>
 #include <linux/pagemap.h>
+#include <linux/writeback.h>
 #include "hash.h"
 #include "crc32c.h"
 #include "ctree.h"
@@ -1058,6 +1059,26 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
         }
 }
 
+static u64 reduce_alloc_profile(u64 flags)
+{
+        if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
+            (flags & (BTRFS_BLOCK_GROUP_RAID1 |
+                      BTRFS_BLOCK_GROUP_RAID10)))
+                flags &= ~BTRFS_BLOCK_GROUP_DUP;
+
+        if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
+            (flags & BTRFS_BLOCK_GROUP_RAID10))
+                flags &= ~BTRFS_BLOCK_GROUP_RAID1;
+
+        if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
+            ((flags & BTRFS_BLOCK_GROUP_RAID1) |
+             (flags & BTRFS_BLOCK_GROUP_RAID10) |
+             (flags & BTRFS_BLOCK_GROUP_DUP)))
+                flags &= ~BTRFS_BLOCK_GROUP_RAID0;
+        return flags;
+}
+
+
 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
                           struct btrfs_root *extent_root, u64 alloc_bytes,
                           u64 flags)
@@ -1068,6 +1089,8 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans,
         u64 num_bytes;
         int ret;
 
+        flags = reduce_alloc_profile(flags);
+
         space_info = __find_space_info(extent_root->fs_info, flags);
         if (!space_info) {
                 ret = update_space_info(extent_root->fs_info, flags,
@@ -1684,6 +1707,7 @@ enospc:
 error:
         return ret;
 }
+
 /*
  * finds a free extent and does all the dirty work required for allocation
  * returns the key for the extent through ins, and a tree buffer for
@@ -1697,7 +1721,7 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                        u64 root_objectid, u64 ref_generation,
                        u64 owner, u64 owner_offset,
                        u64 empty_size, u64 hint_byte,
-                       u64 search_end, struct btrfs_key *ins, int data)
+                       u64 search_end, struct btrfs_key *ins, u64 data)
 {
         int ret;
         int pending_ret;
@@ -1727,6 +1751,7 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                 data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile;
         }
 again:
+        data = reduce_alloc_profile(data);
         if (root->ref_cows) {
                 if (!(data & BTRFS_BLOCK_GROUP_METADATA)) {
                         ret = do_chunk_alloc(trans, root->fs_info->extent_root,
@@ -1752,6 +1777,9 @@ again:
                 num_bytes = max(num_bytes, min_alloc_size);
                 goto again;
         }
+        if (ret) {
+                printk("allocation failed flags %Lu\n", data);
+        }
         BUG_ON(ret);
         if (ret)
                 return ret;
@@ -2274,8 +2302,6 @@ static int noinline relocate_inode_pages(struct inode *inode, u64 start,
 {
         u64 page_start;
         u64 page_end;
-        u64 delalloc_start;
-        u64 existing_delalloc;
         unsigned long last_index;
         unsigned long i;
         struct page *page;
@@ -2293,7 +2319,6 @@ static int noinline relocate_inode_pages(struct inode *inode, u64 start,
         ra_pages = BTRFS_I(inode)->root->fs_info->bdi.ra_pages;
 
         file_ra_state_init(ra, inode->i_mapping);
-        kfree(ra);
 
         for (; i <= last_index; i++) {
                 if (total_read % ra_pages == 0) {
@@ -2313,26 +2338,30 @@ static int noinline relocate_inode_pages(struct inode *inode, u64 start,
                                 goto out_unlock;
                         }
                 }
+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
+                ClearPageDirty(page);
+#else
+                cancel_dirty_page(page, PAGE_CACHE_SIZE);
+#endif
+                wait_on_page_writeback(page);
+                set_page_extent_mapped(page);
                 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
                 page_end = page_start + PAGE_CACHE_SIZE - 1;
 
                 lock_extent(io_tree, page_start, page_end, GFP_NOFS);
 
-                delalloc_start = page_start;
-                existing_delalloc = count_range_bits(io_tree,
-                                             &delalloc_start, page_end,
-                                             PAGE_CACHE_SIZE, EXTENT_DELALLOC);
-
+                set_page_dirty(page);
                 set_extent_delalloc(io_tree, page_start,
                                     page_end, GFP_NOFS);
 
                 unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
-                set_page_dirty(page);
                 unlock_page(page);
                 page_cache_release(page);
+                balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
         }
 
 out_unlock:
+        kfree(ra);
         mutex_unlock(&inode->i_mutex);
         return 0;
 }
@@ -2397,8 +2426,6 @@ static int noinline relocate_one_reference(struct btrfs_root *extent_root,
                         goto out;
                 }
                 relocate_inode_pages(inode, ref_offset, extent_key->offset);
-                /* FIXME, data=ordered will help get rid of this */
-                filemap_fdatawrite(inode->i_mapping);
                 iput(inode);
                 mutex_lock(&extent_root->fs_info->fs_mutex);
         } else {
@@ -2486,6 +2513,47 @@ out:
         return ret;
 }
 
+static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
+{
+        u64 num_devices;
+        u64 stripped = BTRFS_BLOCK_GROUP_RAID0 |
+                BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
+
+        num_devices = btrfs_super_num_devices(&root->fs_info->super_copy);
+        if (num_devices == 1) {
+                stripped |= BTRFS_BLOCK_GROUP_DUP;
+                stripped = flags & ~stripped;
+
+                /* turn raid0 into single device chunks */
+                if (flags & BTRFS_BLOCK_GROUP_RAID0)
+                        return stripped;
+
+                /* turn mirroring into duplication */
+                if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
+                             BTRFS_BLOCK_GROUP_RAID10))
+                        return stripped | BTRFS_BLOCK_GROUP_DUP;
+                return flags;
+        } else {
+                /* they already had raid on here, just return */
+                if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
+                    (flags & BTRFS_BLOCK_GROUP_RAID1)) {
+                }
+                if (flags & stripped)
+                        return flags;
+
+                stripped |= BTRFS_BLOCK_GROUP_DUP;
+                stripped = flags & ~stripped;
+
+                /* switch duplicated blocks with raid1 */
+                if (flags & BTRFS_BLOCK_GROUP_DUP)
+                        return stripped | BTRFS_BLOCK_GROUP_RAID1;
+
+                /* turn single device chunks into raid0 */
+                return stripped | BTRFS_BLOCK_GROUP_RAID0;
+        }
+        return flags;
+}
+
 int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start)
 {
         struct btrfs_trans_handle *trans;
@@ -2494,6 +2562,7 @@ int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start)
         u64 cur_byte;
         u64 total_found;
         u64 shrink_last_byte;
+        u64 new_alloc_flags;
         struct btrfs_block_group_cache *shrink_block_group;
         struct btrfs_fs_info *info = root->fs_info;
         struct btrfs_key key;
@@ -2511,17 +2580,20 @@ int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start)
 
         shrink_block_group->space_info->total_bytes -=
                 shrink_block_group->key.offset;
-printk("shrink_extent_tree %Lu -> %Lu type %Lu\n", shrink_start, shrink_last_byte, shrink_block_group->flags);
         path = btrfs_alloc_path();
         root = root->fs_info->extent_root;
         path->reada = 2;
 
 again:
-        trans = btrfs_start_transaction(root, 1);
-        do_chunk_alloc(trans, root->fs_info->extent_root,
+        if (btrfs_block_group_used(&shrink_block_group->item) > 0) {
+                trans = btrfs_start_transaction(root, 1);
+                new_alloc_flags = update_block_group_flags(root,
+                                                   shrink_block_group->flags);
+                do_chunk_alloc(trans, root->fs_info->extent_root,
                         btrfs_block_group_used(&shrink_block_group->item) +
-                        2 * 1024 * 1024, shrink_block_group->flags);
-        btrfs_end_transaction(trans, root);
+                        2 * 1024 * 1024, new_alloc_flags);
+                btrfs_end_transaction(trans, root);
+        }
         shrink_block_group->ro = 1;
 
         total_found = 0;