From: Wang Xiaoguang <[email protected]>

When running inband dedupe with balance, it's possible that inband dedupe
still increase ref on extents which are in RO chunk.

This may cause either find_data_references() gives warning, or make
run_delayed_refs() return -EIO and cause trans abort.

The cause is, normal dedupe_del() is only called at run_delayed_ref()
time, which is too late for balance case.

This patch fixes this bug by calling dedupe_del() at extent searching
time of balance.

Signed-off-by: Wang Xiaoguang <[email protected]>
---
 fs/btrfs/relocation.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 2bd0011..71a5cd0 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -31,6 +31,7 @@
 #include "async-thread.h"
 #include "free-space-cache.h"
 #include "inode-map.h"
+#include "dedupe.h"
 
 /*
  * backref_node, mapping_node and tree_block start with this
@@ -3909,6 +3910,7 @@ static noinline_for_stack int relocate_block_group(struct 
reloc_control *rc)
        struct btrfs_trans_handle *trans = NULL;
        struct btrfs_path *path;
        struct btrfs_extent_item *ei;
+       struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
        u64 flags;
        u32 item_size;
        int ret;
@@ -4032,6 +4034,20 @@ restart:
                        }
                }
 
+               /*
+                * This data extent will be replaced, but normal
+                * dedupe_del() will only happen at run_delayed_ref()
+                * time, which is too late, so delete dedupe hash early
+                * to prevent its ref get increased.
+                */
+               if (rc->stage == MOVE_DATA_EXTENTS &&
+                   (flags & BTRFS_EXTENT_FLAG_DATA)) {
+                       ret = btrfs_dedupe_del(trans, fs_info, key.objectid);
+                       if (ret < 0) {
+                               err = ret;
+                               break;
+                       }
+               }
                btrfs_end_transaction_throttle(trans, rc->extent_root);
                btrfs_btree_balance_dirty(rc->extent_root);
                trans = NULL;
-- 
2.7.3



--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to