btrfs: reorder initialization before the mount locks uuid_mutex

In preparation to take a big lock, move resource initialization before
the critical section. It's not obvious from the diff, the desired order
is:

- initialize mount security options
- allocate temporary fs_info
- allocate superblock buffers

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2018-06-19 18:01:24 +02:00
parent 5139cff598
commit 399f7f4c42

View File

@ -1526,14 +1526,6 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
if (!(flags & SB_RDONLY))
mode |= FMODE_WRITE;
mutex_lock(&uuid_mutex);
error = btrfs_parse_early_options(data, mode, fs_type,
&fs_devices);
mutex_unlock(&uuid_mutex);
if (error) {
return ERR_PTR(error);
}
security_init_mnt_opts(&new_sec_opts);
if (data) {
error = parse_security_options(data, &new_sec_opts);
@ -1541,12 +1533,6 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
return ERR_PTR(error);
}
mutex_lock(&uuid_mutex);
error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
mutex_unlock(&uuid_mutex);
if (error)
goto error_sec_opts;
/*
* 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
@ -1559,8 +1545,6 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
goto error_sec_opts;
}
fs_info->fs_devices = fs_devices;
fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
security_init_mnt_opts(&fs_info->security_opts);
@ -1569,6 +1553,20 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
goto error_fs_info;
}
mutex_lock(&uuid_mutex);
error = btrfs_parse_early_options(data, mode, fs_type, &fs_devices);
mutex_unlock(&uuid_mutex);
if (error)
goto error_fs_info;
mutex_lock(&uuid_mutex);
error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
mutex_unlock(&uuid_mutex);
if (error)
goto error_fs_info;
fs_info->fs_devices = fs_devices;
mutex_lock(&uuid_mutex);
error = btrfs_open_devices(fs_devices, mode, fs_type);
mutex_unlock(&uuid_mutex);