Btrfs: kill free_space pointer from inode structure

Inodes always allocate free space with BTRFS_BLOCK_GROUP_DATA type,
which means every inode has the same BTRFS_I(inode)->free_space pointer.

This shrinks struct btrfs_inode by 4 bytes (or 8 bytes on 64 bits).

Signed-off-by: Li Zefan <lizefan@huawei.com>

4 files changed, 10 insertions, 19 deletions

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 21b8cfe08e95..5b2ad6bc4fe7 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -87,9 +87,6 @@ struct btrfs_inode {
         /* node for the red-black tree that links inodes in subvolume root */
         struct rb_node rb_node;
 
-        /* the space_info for where this inode's data allocations are done */
-        struct btrfs_space_info *space_info;
-
         unsigned long runtime_flags;
 
         /* full 64 bit generation number, struct vfs_inode doesn't have a big
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index fa5c45b39075..6761490b91cd 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1240,6 +1240,8 @@ struct btrfs_fs_info {
          */
         struct list_head space_info;
 
+        struct btrfs_space_info *data_sinfo;
+
         struct reloc_control *reloc_ctl;
 
         spinlock_t delalloc_lock;
@@ -2607,7 +2609,6 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root, u64 group_start);
 u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags);
 u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data);
-void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *ionde);
 void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
 int btrfs_check_data_free_space(struct inode *inode, u64 bytes);
 void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 7843542484c9..6621ed72f3c3 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3139,6 +3139,8 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
         init_waitqueue_head(&found->wait);
         *space_info = found;
         list_add_rcu(&found->list, &info->space_info);
+        if (flags & BTRFS_BLOCK_GROUP_DATA)
+                info->data_sinfo = found;
         return 0;
 }
 
@@ -3268,12 +3270,6 @@ u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
         return get_alloc_profile(root, flags);
 }
 
-void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
-{
-        BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
-                                                       BTRFS_BLOCK_GROUP_DATA);
-}
-
 /*
  * This will check the space that the inode allocates from to make sure we have
  * enough space for bytes.
@@ -3282,6 +3278,7 @@ int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
 {
         struct btrfs_space_info *data_sinfo;
         struct btrfs_root *root = BTRFS_I(inode)->root;
+        struct btrfs_fs_info *fs_info = root->fs_info;
         u64 used;
         int ret = 0, committed = 0, alloc_chunk = 1;
 
@@ -3294,7 +3291,7 @@ int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
                 committed = 1;
         }
 
-        data_sinfo = BTRFS_I(inode)->space_info;
+        data_sinfo = fs_info->data_sinfo;
         if (!data_sinfo)
                 goto alloc;
 
@@ -3335,10 +3332,9 @@ alloc:
                                         goto commit_trans;
                         }
 
-                        if (!data_sinfo) {
-                                btrfs_set_inode_space_info(root, inode);
-                                data_sinfo = BTRFS_I(inode)->space_info;
-                        }
+                        if (!data_sinfo)
+                                data_sinfo = fs_info->data_sinfo;
+
                         goto again;
                 }
 
@@ -3385,7 +3381,7 @@ void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
         /* make sure bytes are sectorsize aligned */
         bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
 
-        data_sinfo = BTRFS_I(inode)->space_info;
+        data_sinfo = root->fs_info->data_sinfo;
         spin_lock(&data_sinfo->lock);
         data_sinfo->bytes_may_use -= bytes;
         trace_btrfs_space_reservation(root->fs_info, "space_info",
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 321c415dea7f..ee45ebf42192 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4082,7 +4082,6 @@ static int btrfs_init_locked_inode(struct inode *inode, void *p)
         struct btrfs_iget_args *args = p;
         inode->i_ino = args->ino;
         BTRFS_I(inode)->root = args->root;
-        btrfs_set_inode_space_info(args->root, inode);
         return 0;
 }
 
@@ -4667,7 +4666,6 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
         BTRFS_I(inode)->root = root;
         BTRFS_I(inode)->generation = trans->transid;
         inode->i_generation = BTRFS_I(inode)->generation;
-        btrfs_set_inode_space_info(root, inode);
 
         if (S_ISDIR(mode))
                 owner = 0;
@@ -6944,7 +6942,6 @@ struct inode *btrfs_alloc_inode(struct super_block *sb)
                 return NULL;
 
         ei->root = NULL;
-        ei->space_info = NULL;
         ei->generation = 0;
         ei->last_trans = 0;
         ei->last_sub_trans = 0;