mount ro and remount support

diff -urp 2/fs/btrfs/ctree.h 3/fs/btrfs/ctree.h
@@ -541,6 +541,7 @@ struct btrfs_space_info {
 	u64 bytes_used;
 	u64 bytes_pinned;
 	u64 bytes_reserved;
+	u64 bytes_readonly;
 	int full;
 	int force_alloc;
 	struct list_head list;

140 lines not on this page · raw message

diff -urp 2/fs/btrfs/disk-io.h 3/fs/btrfs/disk-io.h
@@ -38,6 +38,7 @@ struct btrfs_root *open_ctree(struct sup
 int close_ctree(struct btrfs_root *root);
 int write_ctree_super(struct btrfs_trans_handle *trans,
 		      struct btrfs_root *root);
+int btrfs_commit_super(struct btrfs_root *root);
 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 					    u64 bytenr, u32 blocksize);
 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,

@@ -49,6 +50,7 @@ struct btrfs_root *btrfs_read_fs_root_no
 					       struct btrfs_key *location);
 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 					      struct btrfs_key *location);
+int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
 int btrfs_insert_dev_radix(struct btrfs_root *root,
 			   struct block_device *bdev,
 			   u64 device_id,

139 lines not on this page · raw message

diff -urp 2/fs/btrfs/inode.c 3/fs/btrfs/inode.c
@@ -1808,10 +1808,6 @@ void btrfs_orphan_cleanup(struct btrfs_r
 	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(struc
 	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(struc
 		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 *inod
 	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 b
 	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,

diff -urp 2/fs/btrfs/ioctl.c 3/fs/btrfs/ioctl.c
@@ -378,6 +378,9 @@ static int btrfs_ioctl_resize(struct btr
 	int namelen;
 	int mod = 0;
 
+	if (root->fs_info->sb->s_flags & MS_RDONLY)
+		return -EROFS;
+
 	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 
 	if (!vol_args)

@@ -478,6 +481,9 @@ static noinline int btrfs_ioctl_snap_cre
 	int namelen;
 	int ret;
 
+	if (root->fs_info->sb->s_flags & MS_RDONLY)
+		return -EROFS;
+
 	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 
 	if (!vol_args)

@@ -534,6 +540,11 @@ static int btrfs_ioctl_defrag(struct fil
 {
 	struct inode *inode = fdentry(file)->d_inode;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
+	int ret;
+
+	ret = mnt_want_write(file->f_path.mnt);
+	if (ret)
+		return ret;
 
 	switch (inode->i_mode & S_IFMT) {
 	case S_IFDIR:

@@ -575,6 +586,9 @@ long btrfs_ioctl_rm_dev(struct btrfs_roo
 	struct btrfs_ioctl_vol_args *vol_args;
 	int ret;
 
+	if (root->fs_info->sb->s_flags & MS_RDONLY)
+		return -EROFS;
+
 	vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
 
 	if (!vol_args)

@@ -607,6 +621,10 @@ long btrfs_ioctl_clone(struct file *file
 	int slot;
 	int ret;
 
+	ret = mnt_want_write(file->f_path.mnt);
+	if (ret)
+		return ret;
+
 	src_file = fget(src_fd);
 	if (!src_file)
 		return -EBADF;

@@ -789,6 +807,10 @@ long btrfs_ioctl_trans_start(struct file
 		goto out;
 	}
 
+	ret = mnt_want_write(file->f_path.mnt);
+	if (ret)
+		goto out;
+
 	mutex_lock(&root->fs_info->trans_mutex);
 	root->fs_info->open_ioctl_trans++;
 	mutex_unlock(&root->fs_info->trans_mutex);

diff -urp 2/fs/btrfs/super.c 3/fs/btrfs/super.c
@@ -370,6 +370,9 @@ int btrfs_sync_fs(struct super_block *sb
 	int ret;
 	root = btrfs_sb(sb);
 
+	if (sb->s_flags & MS_RDONLY)
+		return 0;
+
 	sb->s_dirt = 0;
 	if (!wait) {
 		filemap_flush(root->fs_info->btree_inode->i_mapping);

@@ -438,7 +441,7 @@ static int btrfs_get_sb(struct file_syst
 			up_write(&s->s_umount);
 			deactivate_super(s);
 			error = -EBUSY;
-			goto error_bdev;
+			goto error_close_devices;
 		}
 
 	} else {

@@ -487,7 +490,7 @@ static int btrfs_get_sb(struct file_syst
 
 error_s:
 	error = PTR_ERR(s);
-error_bdev:
+error_close_devices:
 	btrfs_close_devices(fs_devices);
 error_free_subvol_name:
 	kfree(subvol_name);

@@ -495,6 +498,35 @@ error:
 	return error;
 }
 
+static int btrfs_remount(struct super_block *sb, int *flags, char *data)
+{
+	struct btrfs_root *root = btrfs_sb(sb);
+	int ret;
+
+	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
+		return 0;
+
+	if (*flags & MS_RDONLY) {
+		sb->s_flags |= MS_RDONLY;
+
+		ret =  btrfs_commit_super(root);
+		WARN_ON(ret);
+	} else {
+		if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
+			return -EINVAL;
+
+		ret = btrfs_cleanup_reloc_trees(root);
+		WARN_ON(ret);
+
+		ret = btrfs_cleanup_fs_roots(root->fs_info);
+		WARN_ON(ret);
+
+		sb->s_flags &= ~MS_RDONLY;
+	}
+
+	return 0;
+}
+
 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
 	struct btrfs_root *root = btrfs_sb(dentry->d_sb);

@@ -582,6 +614,7 @@ static struct super_operations btrfs_sup
 	.alloc_inode	= btrfs_alloc_inode,
 	.destroy_inode	= btrfs_destroy_inode,
 	.statfs		= btrfs_statfs,
+	.remount_fs	= btrfs_remount,
 	.write_super_lockfs = btrfs_write_super_lockfs,
 	.unlockfs	= btrfs_unlockfs,
 };