btrfs: qgroup: remove ASYNC_COMMIT mechanism in favor of reserve retry-after-EDQUOT

commit a514d63882c3 ("btrfs: qgroup: Commit transaction in advance to
reduce early EDQUOT") tries to reduce the early EDQUOT problems by
checking the qgroup free against threshold and tries to wake up commit
kthread to free some space.

The problem of that mechanism is, it can only free qgroup per-trans
metadata space, can't do anything to data, nor prealloc qgroup space.

Now since we have the ability to flush qgroup space, and implemented
retry-after-EDQUOT behavior, such mechanism can be completely replaced.

So this patch will cleanup such mechanism in favor of
retry-after-EDQUOT.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 13a0524cc048c796328636f2eec3d1c7051ba128..050760dfc56db8cef45ed0d557e9724ba92232eb 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -545,11 +545,6 @@ enum {
         * (device replace, resize, device add/delete, balance)
         */
        BTRFS_FS_EXCL_OP,
-       /*
-        * To info transaction_kthread we need an immediate commit so it
-        * doesn't need to wait for commit_interval
-        */
-       BTRFS_FS_NEED_ASYNC_COMMIT,
        /*
         * Indicate that balance has been set up from the ioctl and is in the
         * main phase. The fs_info::balance_ctl is initialized.

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 4360937acc2f77a3ad851c68ddbe4438216af014..c850d7f44fbe82be15d37dad2bda72963e37ac22 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1810,7 +1810,6 @@ static int transaction_kthread(void *arg)
 
                now = ktime_get_seconds();
                if (cur->state < TRANS_STATE_COMMIT_START &&
-                   !test_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags) &&
                    (now < cur->start_time ||
                     now - cur->start_time < fs_info->commit_interval)) {
                        spin_unlock(&fs_info->trans_lock);

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 23579dc39fa6973aaa5aeb3b7e7918a39b538813..c0f350c3a0cf478da93836005bb4818f9f2a0af4 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -11,7 +11,6 @@
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 #include <linux/btrfs.h>
-#include <linux/sizes.h>
 
 #include "ctree.h"
 #include "transaction.h"
@@ -2895,20 +2894,8 @@ out:
        return ret;
 }
 
-/*
- * Two limits to commit transaction in advance.
- *
- * For RATIO, it will be 1/RATIO of the remaining limit as threshold.
- * For SIZE, it will be in byte unit as threshold.
- */
-#define QGROUP_FREE_RATIO              32
-#define QGROUP_FREE_SIZE               SZ_32M
-static bool qgroup_check_limits(struct btrfs_fs_info *fs_info,
-                               const struct btrfs_qgroup *qg, u64 num_bytes)
+static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes)
 {
-       u64 free;
-       u64 threshold;
-
        if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
            qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer)
                return false;
@@ -2917,32 +2904,6 @@ static bool qgroup_check_limits(struct btrfs_fs_info *fs_info,
            qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl)
                return false;
 
-       /*
-        * Even if we passed the check, it's better to check if reservation
-        * for meta_pertrans is pushing us near limit.
-        * If there is too much pertrans reservation or it's near the limit,
-        * let's try commit transaction to free some, using transaction_kthread
-        */
-       if ((qg->lim_flags & (BTRFS_QGROUP_LIMIT_MAX_RFER |
-                             BTRFS_QGROUP_LIMIT_MAX_EXCL))) {
-               if (qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) {
-                       free = qg->max_excl - qgroup_rsv_total(qg) - qg->excl;
-                       threshold = min_t(u64, qg->max_excl / QGROUP_FREE_RATIO,
-                                         QGROUP_FREE_SIZE);
-               } else {
-                       free = qg->max_rfer - qgroup_rsv_total(qg) - qg->rfer;
-                       threshold = min_t(u64, qg->max_rfer / QGROUP_FREE_RATIO,
-                                         QGROUP_FREE_SIZE);
-               }
-
-               /*
-                * Use transaction_kthread to commit transaction, so we no
-                * longer need to bother nested transaction nor lock context.
-                */
-               if (free < threshold)
-                       btrfs_commit_transaction_locksafe(fs_info);
-       }
-
        return true;
 }
 
@@ -2990,7 +2951,7 @@ static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce,
 
                qg = unode_aux_to_qgroup(unode);
 
-               if (enforce && !qgroup_check_limits(fs_info, qg, num_bytes)) {
+               if (enforce && !qgroup_check_limits(qg, num_bytes)) {
                        ret = -EDQUOT;
                        goto out;
                }

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3a7c392fbcc90b2c53e321603b8554516c3c67e1..efafc286323c189d19bac9046ce6d29c938a8a64 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -2351,7 +2351,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
         */
        cur_trans->state = TRANS_STATE_COMPLETED;
        wake_up(&cur_trans->commit_wait);
-       clear_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags);
 
        spin_lock(&fs_info->trans_lock);
        list_del_init(&cur_trans->list);

diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 98f7860af5e99ebc524ea0e704ca90c19e3185b9..d60b055b8695a9e8b41534077d9448d63668bb28 100644 (file)
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -210,20 +210,6 @@ int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root);
 int btrfs_commit_transaction(struct btrfs_trans_handle *trans);
 int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
                                   int wait_for_unblock);
-
-/*
- * Try to commit transaction asynchronously, so this is safe to call
- * even holding a spinlock.
- *
- * It's done by informing transaction_kthread to commit transaction without
- * waiting for commit interval.
- */
-static inline void btrfs_commit_transaction_locksafe(
-               struct btrfs_fs_info *fs_info)
-{
-       set_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags);
-       wake_up_process(fs_info->transaction_kthread);
-}
 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans);
 int btrfs_should_end_transaction(struct btrfs_trans_handle *trans);
 void btrfs_throttle(struct btrfs_fs_info *fs_info);