Btrfs: mount ro and remount support

This patch adds mount ro and remount support. The main
changes in patch are: adding btrfs_remount and related
helper function; splitting the transaction related code
out of close_ctree into btrfs_commit_super; updating
allocator to properly handle read only block group.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>

1 files changed, 5 insertions, 10 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 2ed2deacde90..3e3620e69bb9 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1808,10 +1808,6 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
         struct inode *inode;
         int ret = 0, nr_unlink = 0, nr_truncate = 0;
 
-        /* don't do orphan cleanup if the fs is readonly. */
-        if (root->fs_info->sb->s_flags & MS_RDONLY)
-                return;
-
         path = btrfs_alloc_path();
         if (!path)
                 return;
@@ -3050,7 +3046,7 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
         struct btrfs_root *root = bi->root;
         struct btrfs_root *sub_root = root;
         struct btrfs_key location;
-        int ret, new, do_orphan = 0;
+        int ret, new;
 
         if (dentry->d_name.len > BTRFS_NAME_LEN)
                 return ERR_PTR(-ENAMETOOLONG);
@@ -3076,13 +3072,9 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
                 if (new && root != sub_root) {
                         igrab(inode);
                         sub_root->inode = inode;
-                        do_orphan = 1;
                 }
         }
 
-        if (unlikely(do_orphan))
-                btrfs_orphan_cleanup(sub_root);
-
         return d_splice_alias(inode, dentry);
 }
 
@@ -3237,7 +3229,7 @@ int btrfs_write_inode(struct inode *inode, int wait)
         struct btrfs_trans_handle *trans;
         int ret = 0;
 
-        if (root->fs_info->closing > 1)
+        if (root->fs_info->btree_inode == inode)
                 return 0;
 
         if (wait) {
@@ -4625,6 +4617,9 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root)
         struct inode *inode;
         unsigned long flags;
 
+        if (root->fs_info->sb->s_flags & MS_RDONLY)
+                return -EROFS;
+
         spin_lock_irqsave(&root->fs_info->delalloc_lock, flags);
         while(!list_empty(head)) {
                 binode = list_entry(head->next, struct btrfs_inode,