Commit bd7c1ea3 authored by Boris Burkov's avatar Boris Burkov Committed by David Sterba
Browse files

btrfs: qgroup: check generation when recording simple quota delta 



Simple quotas count extents only from the moment the feature is enabled.
Therefore, if we do something like:

1. create subvol S
2. write F in S
3. enable quotas
4. remove F
5. write G in S

then after 3. and 4. we would expect the simple quota usage of S to be 0
(putting aside some metadata extents that might be written) and after
5., it should be the size of G plus metadata. Therefore, we need to be
able to determine whether a particular quota delta we are processing
predates simple quota enablement.

To do this, store the transaction id when quotas were enabled. In
fs_info for immediate use and in the quota status item to make it
recoverable on mount. When we see a delta, check if the generation of
the extent item is less than that of quota enablement. If so, we should
ignore the delta from this extent.

Signed-off-by: default avatarBoris Burkov <boris@bur.io>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 5343cd93

fs/btrfs/accessors.h

+2 −0
Original line number Diff line number Diff line
@@ -980,6 +980,8 @@ BTRFS_SETGET_FUNCS(qgroup_status_flags, struct btrfs_qgroup_status_item, 
		   flags, 64);

BTRFS_SETGET_FUNCS(qgroup_status_rescan, struct btrfs_qgroup_status_item,

		   rescan, 64);

BTRFS_SETGET_FUNCS(qgroup_status_enable_gen, struct btrfs_qgroup_status_item,

		   enable_gen, 64);



/* btrfs_qgroup_info_item */

BTRFS_SETGET_FUNCS(qgroup_info_generation, struct btrfs_qgroup_info_item,

fs/btrfs/extent-tree.c

+4 −0
Original line number Diff line number Diff line
@@ -1566,6 +1566,7 @@ static int run_delayed_data_ref(struct btrfs_trans_handle *trans, 
			.rsv_bytes = href->reserved_bytes,

			.is_data = true,

			.is_inc	= true,

			.generation = trans->transid,

		};



		if (extent_op)
@@ -1738,6 +1739,7 @@ static int run_delayed_tree_ref(struct btrfs_trans_handle *trans, 
			.rsv_bytes = 0,

			.is_data = false,

			.is_inc = true,

			.generation = trans->transid,

		};



		BUG_ON(!extent_op || !extent_op->update_flags);
@@ -3287,6 +3289,7 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans, 
			.rsv_bytes = 0,

			.is_data = is_data,

			.is_inc = false,

			.generation = btrfs_extent_generation(leaf, ei),

		};



		/* In this branch refs == 1 */
@@ -4924,6 +4927,7 @@ int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans, 
	struct btrfs_squota_delta delta = {

		.root = root_objectid,

		.num_bytes = ins->offset,

		.generation = trans->transid,

		.rsv_bytes = 0,

		.is_data = true,

		.is_inc = true,

fs/btrfs/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -687,6 +687,7 @@ struct btrfs_fs_info { 
	/* Protected by qgroup_rescan_lock */

	bool qgroup_rescan_running;

	u8 qgroup_drop_subtree_thres;

	u64 qgroup_enable_gen;



	/*

	 * If this is not 0, then it indicates a serious filesystem error has

fs/btrfs/qgroup.c

+22 −6
Original line number Diff line number Diff line
@@ -369,6 +369,15 @@ static void qgroup_mark_inconsistent(struct btrfs_fs_info *fs_info) 
				  BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING);

}



static void qgroup_read_enable_gen(struct btrfs_fs_info *fs_info,

				   struct extent_buffer *leaf, int slot,

				   struct btrfs_qgroup_status_item *ptr)

{

	ASSERT(btrfs_fs_incompat(fs_info, SIMPLE_QUOTA));

	ASSERT(btrfs_item_size(leaf, slot) >= sizeof(*ptr));

	fs_info->qgroup_enable_gen = btrfs_qgroup_status_enable_gen(leaf, ptr);

}



/*

 * The full config is read in one go, only called from open_ctree()

 * It doesn't use any locking, as at this point we're still single-threaded
@@ -384,7 +393,6 @@ int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info) 
	int ret = 0;

	u64 flags = 0;

	u64 rescan_progress = 0;

	bool simple;



	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED)

		return 0;
@@ -437,9 +445,9 @@ int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info) 
				goto out;

			}

			fs_info->qgroup_flags = btrfs_qgroup_status_flags(l, ptr);

			simple = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE);

			if (btrfs_qgroup_status_generation(l, ptr) !=

			    fs_info->generation && !simple) {

			if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE) {

				qgroup_read_enable_gen(fs_info, l, slot, ptr);

			} else if (btrfs_qgroup_status_generation(l, ptr) != fs_info->generation) {

				qgroup_mark_inconsistent(fs_info);

				btrfs_err(fs_info,

					"qgroup generation mismatch, marked as inconsistent");
@@ -1103,10 +1111,12 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info, 
	btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid);

	btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION);

	fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON;

	if (simple)

	if (simple) {

		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE;

	else

		btrfs_set_qgroup_status_enable_gen(leaf, ptr, trans->transid);

	} else {

		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;

	}

	btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags &

				      BTRFS_QGROUP_STATUS_FLAGS_MASK);

	btrfs_set_qgroup_status_rescan(leaf, ptr, 0);
@@ -1210,6 +1220,8 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info, 
		goto out_free_path;

	}



	fs_info->qgroup_enable_gen = trans->transid;



	mutex_unlock(&fs_info->qgroup_ioctl_lock);

	/*

	 * Commit the transaction while not holding qgroup_ioctl_lock, to avoid
@@ -4655,6 +4667,10 @@ int btrfs_record_squota_delta(struct btrfs_fs_info *fs_info, 
	if (!is_fstree(root))

		return 0;



	/* If the extent predates enabling quotas, don't count it. */

	if (delta->generation < fs_info->qgroup_enable_gen)

		return 0;



	spin_lock(&fs_info->qgroup_lock);

	qgroup = find_qgroup_rb(fs_info, root);

	if (!qgroup) {

fs/btrfs/qgroup.h

+2 −0
Original line number Diff line number Diff line
@@ -276,6 +276,8 @@ struct btrfs_squota_delta { 
	u64 num_bytes;

	/* The number of bytes reserved for this extent. */

	u64 rsv_bytes;

	/* The generation the extent was created in. */

	u64 generation;

	/* Whether we are using or freeing the extent. */

	bool is_inc;

	/* Whether the extent is data or metadata. */