Btrfs: Reduce stack usage in the resizer, fix 32 bit compiles

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

5 files changed, 63 insertions, 43 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index d6e5c19969b0..9873975ce0ee 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -386,6 +386,7 @@ struct btrfs_root {
         int defrag_running;
         int defrag_level;
         char *name;
+        int in_sysfs;
 };
 
 /*
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index de026d9d9b2b..67d9fd728868 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -374,6 +374,7 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
         root->highest_inode = 0;
         root->last_inode_alloc = 0;
         root->name = NULL;
+        root->in_sysfs = 0;
         memset(&root->root_key, 0, sizeof(root->root_key));
         memset(&root->root_item, 0, sizeof(root->root_item));
         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
@@ -516,6 +517,9 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
         if (!root)
                 return NULL;
 
+        if (root->in_sysfs)
+                return root;
+
         ret = btrfs_set_root_name(root, name, namelen);
         if (ret) {
                 free_extent_buffer(root->node);
@@ -530,6 +534,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                 kfree(root);
                 return ERR_PTR(ret);
         }
+        root->in_sysfs = 1;
         return root;
 }
 #if 0
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 91c2b27d9689..6137f06091e8 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -751,7 +751,7 @@ again:
 
                 if (found_objectid != root_objectid) {
                         total_count = 2;
-                        break;
+                        goto out;
                 }
                 total_count = 1;
                 path->slots[0]++;
@@ -760,8 +760,6 @@ again:
                 total_count = 0;
                 goto out;
         }
-        if (total_count > 1)
-                goto out;
         if (level >= 0 && root->node == count_path->nodes[level])
                 goto out;
         level++;
@@ -2109,22 +2107,23 @@ static int relocate_inode_pages(struct inode *inode, u64 start, u64 len)
         u64 delalloc_start;
         u64 existing_delalloc;
         unsigned long last_index;
-        unsigned long first_index;
         unsigned long i;
         struct page *page;
         struct btrfs_root *root = BTRFS_I(inode)->root;
         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
-        struct file_ra_state ra;
+        struct file_ra_state *ra;
+
+        ra = kzalloc(sizeof(*ra), GFP_NOFS);
 
         mutex_lock(&inode->i_mutex);
-        first_index = start >> PAGE_CACHE_SHIFT;
+        i = start >> PAGE_CACHE_SHIFT;
         last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
 
-        memset(&ra, 0, sizeof(ra));
-        file_ra_state_init(&ra, inode->i_mapping);
-        btrfs_force_ra(inode->i_mapping, &ra, NULL, first_index, last_index);
+        file_ra_state_init(ra, inode->i_mapping);
+        btrfs_force_ra(inode->i_mapping, ra, NULL, i, last_index);
+        kfree(ra);
 
-        for (i = first_index; i <= last_index; i++) {
+        for (; i <= last_index; i++) {
                 page = grab_cache_page(inode->i_mapping, i);
                 if (!page)
                         goto out_unlock;
@@ -2167,27 +2166,43 @@ out_unlock:
         return 0;
 }
 
+/*
+ * note, this releases the path
+ */
 static int relocate_one_reference(struct btrfs_root *extent_root,
                                   struct btrfs_path *path,
-                                  struct btrfs_key *extent_key,
-                                  u64 ref_root, u64 ref_gen, u64 ref_objectid,
-                                  u64 ref_offset)
+                                  struct btrfs_key *extent_key)
 {
         struct inode *inode;
         struct btrfs_root *found_root;
-        struct btrfs_key root_location;
+        struct btrfs_key *root_location;
+        struct btrfs_extent_ref *ref;
+        u64 ref_root;
+        u64 ref_gen;
+        u64 ref_objectid;
+        u64 ref_offset;
         int ret;
 
-        root_location.objectid = ref_root;
+        ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                             struct btrfs_extent_ref);
+        ref_root = btrfs_ref_root(path->nodes[0], ref);
+        ref_gen = btrfs_ref_generation(path->nodes[0], ref);
+        ref_objectid = btrfs_ref_objectid(path->nodes[0], ref);
+        ref_offset = btrfs_ref_offset(path->nodes[0], ref);
+        btrfs_release_path(extent_root, path);
+
+        root_location = kmalloc(sizeof(*root_location), GFP_NOFS);
+        root_location->objectid = ref_root;
         if (ref_gen == 0)
-                root_location.offset = 0;
+                root_location->offset = 0;
         else
-                root_location.offset = (u64)-1;
-        root_location.type = BTRFS_ROOT_ITEM_KEY;
+                root_location->offset = (u64)-1;
+        root_location->type = BTRFS_ROOT_ITEM_KEY;
 
         found_root = btrfs_read_fs_root_no_name(extent_root->fs_info,
-                                                &root_location);
+                                                root_location);
         BUG_ON(!found_root);
+        kfree(root_location);
 
         if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) {
                 mutex_unlock(&extent_root->fs_info->fs_mutex);
@@ -2259,12 +2274,7 @@ static int relocate_one_extent(struct btrfs_root *extent_root,
 {
         struct btrfs_key key;
         struct btrfs_key found_key;
-        struct btrfs_extent_ref *ref;
         struct extent_buffer *leaf;
-        u64 ref_root;
-        u64 ref_gen;
-        u64 ref_objectid;
-        u64 ref_offset;
         u32 nritems;
         u32 item_size;
         int ret = 0;
@@ -2297,17 +2307,7 @@ static int relocate_one_extent(struct btrfs_root *extent_root,
                 key.offset = found_key.offset + 1;
                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
 
-                ref = btrfs_item_ptr(leaf, path->slots[0],
-                                     struct btrfs_extent_ref);
-                ref_root = btrfs_ref_root(leaf, ref);
-                ref_gen = btrfs_ref_generation(leaf, ref);
-                ref_objectid = btrfs_ref_objectid(leaf, ref);
-                ref_offset = btrfs_ref_offset(leaf, ref);
-                btrfs_release_path(extent_root, path);
-
-                ret = relocate_one_reference(extent_root, path,
-                                             extent_key, ref_root, ref_gen,
-                                             ref_objectid, ref_offset);
+                ret = relocate_one_reference(extent_root, path, extent_key);
                 if (ret)
                         goto out;
         }
@@ -2354,7 +2354,6 @@ int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size)
         struct btrfs_path *path;
         u64 cur_byte;
         u64 total_found;
-        u64 ptr;
         struct btrfs_fs_info *info = root->fs_info;
         struct extent_map_tree *block_group_cache;
         struct btrfs_key key;
@@ -2377,6 +2376,7 @@ again:
         key.offset = 0;
         key.type = 0;
         while(1) {
+
                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
                 if (ret < 0)
                         goto out;
@@ -2441,6 +2441,8 @@ next:
         key.offset = 0;
         key.type = 0;
         while(1) {
+                u64 ptr;
+
                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
                 if (ret < 0)
                         goto out;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5003a86510a1..b62f35e862bd 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2108,7 +2108,8 @@ static void btrfs_truncate(struct inode *inode)
         btrfs_btree_balance_dirty(root, nr);
 }
 
-static int create_subvol(struct btrfs_root *root, char *name, int namelen)
+static int noinline create_subvol(struct btrfs_root *root, char *name,
+                                  int namelen)
 {
         struct btrfs_trans_handle *trans;
         struct btrfs_key key;
@@ -2492,7 +2493,8 @@ out:
         return ret;
 }
 
-static int btrfs_ioctl_snap_create(struct btrfs_root *root, void __user *arg)
+static int noinline btrfs_ioctl_snap_create(struct btrfs_root *root,
+                                            void __user *arg)
 {
         struct btrfs_ioctl_vol_args *vol_args;
         struct btrfs_dir_item *di;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 1ad611b9f61b..02721eea9a7a 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -481,12 +481,10 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         struct btrfs_transaction *cur_trans;
         struct btrfs_transaction *prev_trans = NULL;
         struct list_head dirty_fs_roots;
-        struct extent_map_tree pinned_copy;
+        struct extent_map_tree *pinned_copy;
         DEFINE_WAIT(wait);
         int ret;
 
-        extent_map_tree_init(&pinned_copy,
-                             root->fs_info->btree_inode->i_mapping, GFP_NOFS);
         INIT_LIST_HEAD(&dirty_fs_roots);
 
         mutex_lock(&root->fs_info->trans_mutex);
@@ -507,6 +505,14 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                 mutex_lock(&root->fs_info->fs_mutex);
                 return 0;
         }
+
+        pinned_copy = kmalloc(sizeof(*pinned_copy), GFP_NOFS);
+        if (!pinned_copy)
+                return -ENOMEM;
+
+        extent_map_tree_init(pinned_copy,
+                             root->fs_info->btree_inode->i_mapping, GFP_NOFS);
+
         trans->transaction->in_commit = 1;
         cur_trans = trans->transaction;
         if (cur_trans->list.prev != &root->fs_info->trans_list) {
@@ -568,16 +574,20 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                             &root->fs_info->super_copy, 0,
                             sizeof(root->fs_info->super_copy));
 
-        btrfs_copy_pinned(root, &pinned_copy);
+        btrfs_copy_pinned(root, pinned_copy);
 
         mutex_unlock(&root->fs_info->trans_mutex);
         mutex_unlock(&root->fs_info->fs_mutex);
         ret = btrfs_write_and_wait_transaction(trans, root);
         BUG_ON(ret);
         write_ctree_super(trans, root);
+
         mutex_lock(&root->fs_info->fs_mutex);
-        btrfs_finish_extent_commit(trans, root, &pinned_copy);
+        btrfs_finish_extent_commit(trans, root, pinned_copy);
         mutex_lock(&root->fs_info->trans_mutex);
+
+        kfree(pinned_copy);
+
         cur_trans->commit_done = 1;
         root->fs_info->last_trans_committed = cur_trans->transid;
         wake_up(&cur_trans->commit_wait);