From f59c0347d4be22dad5812b5b14bf94ac0efd371a Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 12 Dec 2017 15:34:24 +0800 Subject: [PATCH] btrfs: qgroup: Introduce helpers to update and access new qgroup rsv Introduce helpers to: 1) Get total reserved space For limit calculation 2) Add/release reserved space for given type With underflow detection and warning 3) Add/release reserved space according to child qgroup Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/qgroup.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index d6ab07f40f82..252af87340cc 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -47,6 +47,74 @@ * - check all ioctl parameters */ +/* + * Helpers to access qgroup reservation + * + * Callers should ensure the lock context and type are valid + */ + +static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup) +{ + u64 ret = 0; + int i; + + for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) + ret += qgroup->rsv.values[i]; + + return ret; +} + +#ifdef CONFIG_BTRFS_DEBUG +static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type) +{ + if (type == BTRFS_QGROUP_RSV_DATA) + return "data"; + if (type == BTRFS_QGROUP_RSV_META) + return "meta"; + return NULL; +} +#endif + +static void qgroup_rsv_add(struct btrfs_qgroup *qgroup, u64 num_bytes, + enum btrfs_qgroup_rsv_type type) +{ + qgroup->rsv.values[type] += num_bytes; +} + +static void qgroup_rsv_release(struct btrfs_qgroup *qgroup, u64 num_bytes, + enum btrfs_qgroup_rsv_type type) +{ + if (qgroup->rsv.values[type] >= num_bytes) { + qgroup->rsv.values[type] -= num_bytes; + return; + } +#ifdef CONFIG_BTRFS_DEBUG + WARN_RATELIMIT(1, + "qgroup %llu %s reserved space underflow, have %llu to free %llu", + qgroup->qgroupid, qgroup_rsv_type_str(type), + qgroup->rsv.values[type], num_bytes); +#endif + qgroup->rsv.values[type] = 0; +} + +static void qgroup_rsv_add_by_qgroup(struct btrfs_qgroup *dest, + struct btrfs_qgroup *src) +{ + int i; + + for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) + qgroup_rsv_add(dest, src->rsv.values[i], i); +} + +static void qgroup_rsv_release_by_qgroup(struct btrfs_qgroup *dest, + struct btrfs_qgroup *src) +{ + int i; + + for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) + qgroup_rsv_release(dest, src->rsv.values[i], i); +} + static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq, int mod) { -- 2.30.2