btrfs: separate superblock items out of fs_info

fs_info has now ~9kb, more than fits into one page. This will cause
mount failure when memory is too fragmented. Top space consumers are
super block structures super_copy and super_for_commit, ~2.8kb each.
Allocate them dynamically. fs_info will be ~3.5kb. (measured on x86_64)

Add a wrapper for freeing fs_info and all of it's dynamically allocated
members.

Signed-off-by: David Sterba <dsterba@suse.cz>

1 files changed, 6 insertions, 11 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index a1cb7821becd..c7fb3a4247d3 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -91,8 +91,7 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
         struct btrfs_csum_item *item;
         struct extent_buffer *leaf;
         u64 csum_offset = 0;
-        u16 csum_size =
-                btrfs_super_csum_size(&root->fs_info->super_copy);
+        u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
         int csums_in_item;
 
         file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
@@ -162,8 +161,7 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
         u64 item_last_offset = 0;
         u64 disk_bytenr;
         u32 diff;
-        u16 csum_size =
-                btrfs_super_csum_size(&root->fs_info->super_copy);
+        u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
         int ret;
         struct btrfs_path *path;
         struct btrfs_csum_item *item = NULL;
@@ -290,7 +288,7 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
         int ret;
         size_t size;
         u64 csum_end;
-        u16 csum_size = btrfs_super_csum_size(&root->fs_info->super_copy);
+        u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
 
         path = btrfs_alloc_path();
         if (!path)
@@ -492,8 +490,7 @@ static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
                                       u64 bytenr, u64 len)
 {
         struct extent_buffer *leaf;
-        u16 csum_size =
-                btrfs_super_csum_size(&root->fs_info->super_copy);
+        u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
         u64 csum_end;
         u64 end_byte = bytenr + len;
         u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
@@ -549,8 +546,7 @@ int btrfs_del_csums(struct btrfs_trans_handle *trans,
         u64 csum_end;
         struct extent_buffer *leaf;
         int ret;
-        u16 csum_size =
-                btrfs_super_csum_size(&root->fs_info->super_copy);
+        u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
         int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
 
         root = root->fs_info->csum_root;
@@ -676,8 +672,7 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
         struct btrfs_sector_sum *sector_sum;
         u32 nritems;
         u32 ins_size;
-        u16 csum_size =
-                btrfs_super_csum_size(&root->fs_info->super_copy);
+        u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
 
         path = btrfs_alloc_path();
         if (!path)