Btrfs: Lower stack usage in transaction.c

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

1 files changed, 24 insertions, 18 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3f64d0c7ddb9..e9a0983897f3 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -33,7 +33,7 @@ static struct workqueue_struct *trans_wq;
 #define BTRFS_ROOT_TRANS_TAG 0
 #define BTRFS_ROOT_DEFRAG_TAG 1
 
-static void put_transaction(struct btrfs_transaction *transaction)
+static noinline void put_transaction(struct btrfs_transaction *transaction)
 {
         WARN_ON(transaction->use_count == 0);
         transaction->use_count--;
@@ -46,7 +46,7 @@ static void put_transaction(struct btrfs_transaction *transaction)
         }
 }
 
-static int join_transaction(struct btrfs_root *root)
+static noinline int join_transaction(struct btrfs_root *root)
 {
         struct btrfs_transaction *cur_trans;
         cur_trans = root->fs_info->running_transaction;
@@ -82,7 +82,7 @@ static int join_transaction(struct btrfs_root *root)
         return 0;
 }
 
-static int record_root_in_trans(struct btrfs_root *root)
+static noinline int record_root_in_trans(struct btrfs_root *root)
 {
         u64 running_trans_id = root->fs_info->running_transaction->transid;
         if (root->ref_cows && root->last_trans < running_trans_id) {
@@ -225,8 +225,8 @@ int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,
         return 0;
 }
 
-static int wait_for_commit(struct btrfs_root *root,
-                           struct btrfs_transaction *commit)
+static noinline int wait_for_commit(struct btrfs_root *root,
+                                    struct btrfs_transaction *commit)
 {
         DEFINE_WAIT(wait);
         mutex_lock(&root->fs_info->trans_mutex);
@@ -265,9 +265,9 @@ int btrfs_add_dead_root(struct btrfs_root *root,
         return 0;
 }
 
-static int add_dirty_roots(struct btrfs_trans_handle *trans,
-                           struct radix_tree_root *radix,
-                           struct list_head *list)
+static noinline int add_dirty_roots(struct btrfs_trans_handle *trans,
+                                    struct radix_tree_root *radix,
+                                    struct list_head *list)
 {
         struct dirty_root *dirty;
         struct btrfs_root *gang[8];
@@ -406,8 +406,8 @@ int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info)
         return err;
 }
 
-static int drop_dirty_roots(struct btrfs_root *tree_root,
-                            struct list_head *list)
+static noinline int drop_dirty_roots(struct btrfs_root *tree_root,
+                                     struct list_head *list)
 {
         struct dirty_root *dirty;
         struct btrfs_trans_handle *trans;
@@ -529,23 +529,28 @@ int btrfs_write_ordered_inodes(struct btrfs_trans_handle *trans,
         return 0;
 }
 
-static int create_pending_snapshot(struct btrfs_trans_handle *trans,
+static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
                                    struct btrfs_fs_info *fs_info,
                                    struct btrfs_pending_snapshot *pending)
 {
         struct btrfs_key key;
-        struct btrfs_root_item new_root_item;
+        struct btrfs_root_item *new_root_item;
         struct btrfs_root *tree_root = fs_info->tree_root;
         struct btrfs_root *root = pending->root;
         struct extent_buffer *tmp;
         int ret;
         u64 objectid;
 
+        new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
+        if (!new_root_item) {
+                ret = -ENOMEM;
+                goto fail;
+        }
         ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid);
         if (ret)
                 goto fail;
 
-        memcpy(&new_root_item, &root->root_item, sizeof(new_root_item));
+        memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
 
         key.objectid = objectid;
         key.offset = 1;
@@ -557,10 +562,10 @@ static int create_pending_snapshot(struct btrfs_trans_handle *trans,
 
         btrfs_copy_root(trans, root, root->node, &tmp, objectid);
 
-        btrfs_set_root_bytenr(&new_root_item, tmp->start);
-        btrfs_set_root_level(&new_root_item, btrfs_header_level(tmp));
+        btrfs_set_root_bytenr(new_root_item, tmp->start);
+        btrfs_set_root_level(new_root_item, btrfs_header_level(tmp));
         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
-                                &new_root_item);
+                                new_root_item);
         free_extent_buffer(tmp);
         if (ret)
                 goto fail;
@@ -581,11 +586,12 @@ static int create_pending_snapshot(struct btrfs_trans_handle *trans,
                              pending->name, strlen(pending->name), objectid,
                              root->fs_info->sb->s_root->d_inode->i_ino);
 fail:
+        kfree(new_root_item);
         return ret;
 }
 
-static int create_pending_snapshots(struct btrfs_trans_handle *trans,
-                                   struct btrfs_fs_info *fs_info)
+static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
+                                             struct btrfs_fs_info *fs_info)
 {
         struct btrfs_pending_snapshot *pending;
         struct list_head *head = &trans->transaction->pending_snapshots;