diff options
| -rw-r--r-- | fs/btrfs/ioctl.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index cacd6ee17d8e..572f57561916 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1600,6 +1600,48 @@ out_ra: return ret; } +/* + * Try to start exclusive operation @type or cancel it if it's running. + * + * Return: + * 0 - normal mode, newly claimed op started + * >0 - normal mode, something else is running, + * return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS to user space + * ECANCELED - cancel mode, successful cancel + * ENOTCONN - cancel mode, operation not running anymore + */ +static int exclop_start_or_cancel_reloc(struct btrfs_fs_info *fs_info, + enum btrfs_exclusive_operation type, bool cancel) +{ + if (!cancel) { + /* Start normal op */ + if (!btrfs_exclop_start(fs_info, type)) + return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; + /* Exclusive operation is now claimed */ + return 0; + } + + /* Cancel running op */ + if (btrfs_exclop_start_try_lock(fs_info, type)) { + /* + * This blocks any exclop finish from setting it to NONE, so we + * request cancellation. Either it runs and we will wait for it, + * or it has finished and no waiting will happen. + */ + atomic_inc(&fs_info->reloc_cancel_req); + btrfs_exclop_start_unlock(fs_info); + + if (test_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags)) + wait_on_bit(&fs_info->flags, BTRFS_FS_RELOC_RUNNING, + TASK_INTERRUPTIBLE); + + return -ECANCELED; + } + + /* Something else is running or none */ + return -ENOTCONN; +} + static noinline int btrfs_ioctl_resize(struct file *file, void __user *arg) { |