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Commit 83bfccb5 authored by Chris Mason's avatar Chris Mason
Browse files

Merge branch 'mutex-ops@next-for-chris' of git://github.com/idryomov/btrfs-unstable into linus

parents daf2c089 25122d15
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+79 −28
Original line number Diff line number Diff line
@@ -1340,7 +1340,7 @@ static noinline int btrfs_ioctl_resize(struct file *file,
			1)) {
		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
		mnt_drop_write_file(file);
		return -EINPROGRESS;
		return -EINVAL;
	}

	mutex_lock(&root->fs_info->volume_mutex);
@@ -1446,8 +1446,8 @@ static noinline int btrfs_ioctl_resize(struct file *file,
	kfree(vol_args);
out:
	mutex_unlock(&root->fs_info->volume_mutex);
	mnt_drop_write_file(file);
	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
	mnt_drop_write_file(file);
	return ret;
}

@@ -2186,19 +2186,20 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
	struct btrfs_ioctl_defrag_range_args *range;
	int ret;

	if (btrfs_root_readonly(root))
		return -EROFS;
	ret = mnt_want_write_file(file);
	if (ret)
		return ret;

	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
			1)) {
		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
		return -EINPROGRESS;
		mnt_drop_write_file(file);
		return -EINVAL;
	}
	ret = mnt_want_write_file(file);
	if (ret) {
		atomic_set(&root->fs_info->mutually_exclusive_operation_running,
			   0);
		return ret;

	if (btrfs_root_readonly(root)) {
		ret = -EROFS;
		goto out;
	}

	switch (inode->i_mode & S_IFMT) {
@@ -2250,8 +2251,8 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
		ret = -EINVAL;
	}
out:
	mnt_drop_write_file(file);
	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
	mnt_drop_write_file(file);
	return ret;
}

@@ -2266,7 +2267,7 @@ static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
			1)) {
		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
		return -EINPROGRESS;
		return -EINVAL;
	}

	mutex_lock(&root->fs_info->volume_mutex);
@@ -2303,7 +2304,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
			1)) {
		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
		mnt_drop_write_file(file);
		return -EINPROGRESS;
		return -EINVAL;
	}

	mutex_lock(&root->fs_info->volume_mutex);
@@ -2319,8 +2320,8 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
	kfree(vol_args);
out:
	mutex_unlock(&root->fs_info->volume_mutex);
	mnt_drop_write_file(file);
	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
	mnt_drop_write_file(file);
	return ret;
}

@@ -3440,8 +3441,8 @@ 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 +3451,61 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg)
	if (ret)
		return ret;

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 +3525,10 @@ 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 +3549,17 @@ 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 +3567,12 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg)

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;
}
+7 −3
Original line number Diff line number Diff line
@@ -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);