diff options
| -rw-r--r-- | fs/btrfs/ioctl.c | 78 | ||||
| -rw-r--r-- | fs/btrfs/volumes.c | 10 |
2 files changed, 71 insertions, 17 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 982c0b9..77d8273 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3440,8 +3440,8 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_ioctl_balance_args *bargs; struct btrfs_balance_control *bctl; + bool need_unlock; /* for mut. excl. ops lock */ int ret; - int need_to_clear_lock = 0; if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -3450,14 +3450,61 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) if (ret) return ret; - mutex_lock(&fs_info->volume_mutex); +again: + if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) { + mutex_lock(&fs_info->volume_mutex); + mutex_lock(&fs_info->balance_mutex); + need_unlock = true; + goto locked; + } + + /* + * mut. excl. ops lock is locked. Three possibilites: + * (1) some other op is running + * (2) balance is running + * (3) balance is paused -- special case (think resume) + */ mutex_lock(&fs_info->balance_mutex); + if (fs_info->balance_ctl) { + /* this is either (2) or (3) */ + if (!atomic_read(&fs_info->balance_running)) { + mutex_unlock(&fs_info->balance_mutex); + if (!mutex_trylock(&fs_info->volume_mutex)) + goto again; + mutex_lock(&fs_info->balance_mutex); + + if (fs_info->balance_ctl && + !atomic_read(&fs_info->balance_running)) { + /* this is (3) */ + need_unlock = false; + goto locked; + } + + mutex_unlock(&fs_info->balance_mutex); + mutex_unlock(&fs_info->volume_mutex); + goto again; + } else { + /* this is (2) */ + mutex_unlock(&fs_info->balance_mutex); + ret = -EINPROGRESS; + goto out; + } + } else { + /* this is (1) */ + mutex_unlock(&fs_info->balance_mutex); + pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n"); + ret = -EINVAL; + goto out; + } + +locked: + BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running)); if (arg) { bargs = memdup_user(arg, sizeof(*bargs)); if (IS_ERR(bargs)) { ret = PTR_ERR(bargs); - goto out; + goto out_unlock; } if (bargs->flags & BTRFS_BALANCE_RESUME) { @@ -3477,13 +3524,10 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) bargs = NULL; } - if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running, - 1)) { - pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n"); + if (fs_info->balance_ctl) { ret = -EINPROGRESS; goto out_bargs; } - need_to_clear_lock = 1; bctl = kzalloc(sizeof(*bctl), GFP_NOFS); if (!bctl) { @@ -3504,11 +3548,17 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) } do_balance: - ret = btrfs_balance(bctl, bargs); /* - * bctl is freed in __cancel_balance or in free_fs_info if - * restriper was paused all the way until unmount + * Ownership of bctl and mutually_exclusive_operation_running + * goes to to btrfs_balance. bctl is freed in __cancel_balance, + * or, if restriper was paused all the way until unmount, in + * free_fs_info. mutually_exclusive_operation_running is + * cleared in __cancel_balance. */ + need_unlock = false; + + ret = btrfs_balance(bctl, bargs); + if (arg) { if (copy_to_user(arg, bargs, sizeof(*bargs))) ret = -EFAULT; @@ -3516,12 +3566,12 @@ do_balance: out_bargs: kfree(bargs); -out: - if (need_to_clear_lock) - atomic_set(&root->fs_info->mutually_exclusive_operation_running, - 0); +out_unlock: mutex_unlock(&fs_info->balance_mutex); mutex_unlock(&fs_info->volume_mutex); + if (need_unlock) + atomic_set(&fs_info->mutually_exclusive_operation_running, 0); +out: mnt_drop_write_file(file); return ret; } diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 86279c3..9c84dbe 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2959,6 +2959,8 @@ static void __cancel_balance(struct btrfs_fs_info *fs_info) unset_balance_control(fs_info); ret = del_balance_item(fs_info->tree_root); BUG_ON(ret); + + atomic_set(&fs_info->mutually_exclusive_operation_running, 0); } void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock, @@ -3138,8 +3140,10 @@ int btrfs_balance(struct btrfs_balance_control *bctl, out: if (bctl->flags & BTRFS_BALANCE_RESUME) __cancel_balance(fs_info); - else + else { kfree(bctl); + atomic_set(&fs_info->mutually_exclusive_operation_running, 0); + } return ret; } @@ -3156,7 +3160,6 @@ static int balance_kthread(void *data) ret = btrfs_balance(fs_info->balance_ctl, NULL); } - atomic_set(&fs_info->mutually_exclusive_operation_running, 0); mutex_unlock(&fs_info->balance_mutex); mutex_unlock(&fs_info->volume_mutex); @@ -3179,7 +3182,6 @@ int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info) return 0; } - WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)); tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance"); if (IS_ERR(tsk)) return PTR_ERR(tsk); @@ -3233,6 +3235,8 @@ int btrfs_recover_balance(struct btrfs_fs_info *fs_info) btrfs_balance_sys(leaf, item, &disk_bargs); btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs); + WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)); + mutex_lock(&fs_info->volume_mutex); mutex_lock(&fs_info->balance_mutex); |
