Btrfs: fix the same inode id problem when doing auto defragment

Two files in the different subvolumes may have the same inode id, so
The rb-tree which is used to manage the defragment object must take it
into account. This patch fix this problem.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>

1 files changed, 39 insertions, 10 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index c9005f216975..2e63cdc2b093 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -65,6 +65,21 @@ struct inode_defrag {
         int cycled;
 };
 
+static int __compare_inode_defrag(struct inode_defrag *defrag1,
+                                  struct inode_defrag *defrag2)
+{
+        if (defrag1->root > defrag2->root)
+                return 1;
+        else if (defrag1->root < defrag2->root)
+                return -1;
+        else if (defrag1->ino > defrag2->ino)
+                return 1;
+        else if (defrag1->ino < defrag2->ino)
+                return -1;
+        else
+                return 0;
+}
+
 /* pop a record for an inode into the defrag tree.  The lock
  * must be held already
  *
@@ -81,15 +96,17 @@ static void __btrfs_add_inode_defrag(struct inode *inode,
         struct inode_defrag *entry;
         struct rb_node **p;
         struct rb_node *parent = NULL;
+        int ret;
 
         p = &root->fs_info->defrag_inodes.rb_node;
         while (*p) {
                 parent = *p;
                 entry = rb_entry(parent, struct inode_defrag, rb_node);
 
-                if (defrag->ino < entry->ino)
+                ret = __compare_inode_defrag(defrag, entry);
+                if (ret < 0)
                         p = &parent->rb_left;
-                else if (defrag->ino > entry->ino)
+                else if (ret > 0)
                         p = &parent->rb_right;
                 else {
                         /* if we're reinserting an entry for
@@ -159,28 +176,35 @@ int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
 /*
  * must be called with the defrag_inodes lock held
  */
-struct inode_defrag *btrfs_find_defrag_inode(struct btrfs_fs_info *info, u64 ino,
+struct inode_defrag *btrfs_find_defrag_inode(struct btrfs_fs_info *info,
+                                             u64 root, u64 ino,
                                              struct rb_node **next)
 {
         struct inode_defrag *entry = NULL;
+        struct inode_defrag tmp;
         struct rb_node *p;
         struct rb_node *parent = NULL;
+        int ret;
+
+        tmp.ino = ino;
+        tmp.root = root;
 
         p = info->defrag_inodes.rb_node;
         while (p) {
                 parent = p;
                 entry = rb_entry(parent, struct inode_defrag, rb_node);
 
-                if (ino < entry->ino)
+                ret = __compare_inode_defrag(&tmp, entry);
+                if (ret < 0)
                         p = parent->rb_left;
-                else if (ino > entry->ino)
+                else if (ret > 0)
                         p = parent->rb_right;
                 else
                         return entry;
         }
 
         if (next) {
-                while (parent && ino > entry->ino) {
+                while (parent && __compare_inode_defrag(&tmp, entry) > 0) {
                         parent = rb_next(parent);
                         entry = rb_entry(parent, struct inode_defrag, rb_node);
                 }
@@ -202,6 +226,7 @@ int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
         struct btrfs_key key;
         struct btrfs_ioctl_defrag_range_args range;
         u64 first_ino = 0;
+        u64 root_objectid = 0;
         int num_defrag;
         int defrag_batch = 1024;
 
@@ -214,11 +239,14 @@ int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
                 n = NULL;
 
                 /* find an inode to defrag */
-                defrag = btrfs_find_defrag_inode(fs_info, first_ino, &n);
+                defrag = btrfs_find_defrag_inode(fs_info, root_objectid,
+                                                 first_ino, &n);
                 if (!defrag) {
-                        if (n)
-                                defrag = rb_entry(n, struct inode_defrag, rb_node);
-                        else if (first_ino) {
+                        if (n) {
+                                defrag = rb_entry(n, struct inode_defrag,
+                                                  rb_node);
+                        } else if (root_objectid || first_ino) {
+                                root_objectid = 0;
                                 first_ino = 0;
                                 continue;
                         } else {
@@ -228,6 +256,7 @@ int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
 
                 /* remove it from the rbtree */
                 first_ino = defrag->ino + 1;
+                root_objectid = defrag->root;
                 rb_erase(&defrag->rb_node, &fs_info->defrag_inodes);
 
                 if (btrfs_fs_closing(fs_info))