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Diffstat (limited to 'fs/btrfs/super.c')
-rw-r--r--fs/btrfs/super.c41
1 files changed, 38 insertions, 3 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8299a25ffc8..dbb51ea7a13 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -244,6 +244,7 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
case Opt_space_cache:
printk(KERN_INFO "btrfs: enabling disk space caching\n");
btrfs_set_opt(info->mount_opt, SPACE_CACHE);
+ break;
case Opt_clear_cache:
printk(KERN_INFO "btrfs: force clearing of disk cache\n");
btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
@@ -562,12 +563,26 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
static int btrfs_test_super(struct super_block *s, void *data)
{
- struct btrfs_fs_devices *test_fs_devices = data;
+ struct btrfs_root *test_root = data;
struct btrfs_root *root = btrfs_sb(s);
- return root->fs_info->fs_devices == test_fs_devices;
+ /*
+ * If this super block is going away, return false as it
+ * can't match as an existing super block.
+ */
+ if (!atomic_read(&s->s_active))
+ return 0;
+ return root->fs_info->fs_devices == test_root->fs_info->fs_devices;
+}
+
+static int btrfs_set_super(struct super_block *s, void *data)
+{
+ s->s_fs_info = data;
+
+ return set_anon_super(s, data);
}
+
/*
* Find a superblock for the given device / mount point.
*
@@ -581,6 +596,8 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
struct super_block *s;
struct dentry *root;
struct btrfs_fs_devices *fs_devices = NULL;
+ struct btrfs_root *tree_root = NULL;
+ struct btrfs_fs_info *fs_info = NULL;
fmode_t mode = FMODE_READ;
char *subvol_name = NULL;
u64 subvol_objectid = 0;
@@ -608,8 +625,24 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
goto error_close_devices;
}
+ /*
+ * Setup a dummy root and fs_info for test/set super. This is because
+ * we don't actually fill this stuff out until open_ctree, but we need
+ * it for searching for existing supers, so this lets us do that and
+ * then open_ctree will properly initialize everything later.
+ */
+ fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
+ tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
+ if (!fs_info || !tree_root) {
+ error = -ENOMEM;
+ goto error_close_devices;
+ }
+ fs_info->tree_root = tree_root;
+ fs_info->fs_devices = fs_devices;
+ tree_root->fs_info = fs_info;
+
bdev = fs_devices->latest_bdev;
- s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
+ s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root);
if (IS_ERR(s))
goto error_s;
@@ -675,6 +708,8 @@ error_s:
error = PTR_ERR(s);
error_close_devices:
btrfs_close_devices(fs_devices);
+ kfree(fs_info);
+ kfree(tree_root);
error_free_subvol_name:
kfree(subvol_name);
return ERR_PTR(error);