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81b29a3bf7
From Dave's testing described below, it's possible to drive a file system to have bogus values of discardable_extents and _bytes. As btrfs_discard_calc_delay() is the only user of discardable_extents, we can correct here for any negative discardable_extents/discardable_bytes. The problem is not reliably reproducible. The workload that created it was based on linux git tree, switching between release tags, then everytihng deleted followed by a full rebalance. At this state the values of discardable_bytes was 16K and discardable_extents was -1, expected values 0 and 0. Repeating the workload again did not correct the bogus values so the offset seems to be stable once it happens. Reported-by: David Sterba <dsterba@suse.com> Signed-off-by: Dennis Zhou <dennis@kernel.org> Signed-off-by: David Sterba <dsterba@suse.com>
703 lines
22 KiB
C
703 lines
22 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/jiffies.h>
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#include <linux/kernel.h>
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#include <linux/ktime.h>
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#include <linux/list.h>
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#include <linux/math64.h>
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#include <linux/sizes.h>
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#include <linux/workqueue.h>
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#include "ctree.h"
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#include "block-group.h"
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#include "discard.h"
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#include "free-space-cache.h"
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/*
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* This contains the logic to handle async discard.
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*
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* Async discard manages trimming of free space outside of transaction commit.
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* Discarding is done by managing the block_groups on a LRU list based on free
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* space recency. Two passes are used to first prioritize discarding extents
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* and then allow for trimming in the bitmap the best opportunity to coalesce.
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* The block_groups are maintained on multiple lists to allow for multiple
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* passes with different discard filter requirements. A delayed work item is
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* used to manage discarding with timeout determined by a max of the delay
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* incurred by the iops rate limit, the byte rate limit, and the max delay of
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* BTRFS_DISCARD_MAX_DELAY.
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*
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* Note, this only keeps track of block_groups that are explicitly for data.
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* Mixed block_groups are not supported.
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*
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* The first list is special to manage discarding of fully free block groups.
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* This is necessary because we issue a final trim for a full free block group
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* after forgetting it. When a block group becomes unused, instead of directly
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* being added to the unused_bgs list, we add it to this first list. Then
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* from there, if it becomes fully discarded, we place it onto the unused_bgs
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* list.
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*
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* The in-memory free space cache serves as the backing state for discard.
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* Consequently this means there is no persistence. We opt to load all the
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* block groups in as not discarded, so the mount case degenerates to the
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* crashing case.
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*
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* As the free space cache uses bitmaps, there exists a tradeoff between
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* ease/efficiency for find_free_extent() and the accuracy of discard state.
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* Here we opt to let untrimmed regions merge with everything while only letting
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* trimmed regions merge with other trimmed regions. This can cause
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* overtrimming, but the coalescing benefit seems to be worth it. Additionally,
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* bitmap state is tracked as a whole. If we're able to fully trim a bitmap,
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* the trimmed flag is set on the bitmap. Otherwise, if an allocation comes in,
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* this resets the state and we will retry trimming the whole bitmap. This is a
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* tradeoff between discard state accuracy and the cost of accounting.
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*/
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/* This is an initial delay to give some chance for block reuse */
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#define BTRFS_DISCARD_DELAY (120ULL * NSEC_PER_SEC)
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#define BTRFS_DISCARD_UNUSED_DELAY (10ULL * NSEC_PER_SEC)
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/* Target completion latency of discarding all discardable extents */
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#define BTRFS_DISCARD_TARGET_MSEC (6 * 60 * 60UL * MSEC_PER_SEC)
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#define BTRFS_DISCARD_MIN_DELAY_MSEC (1UL)
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#define BTRFS_DISCARD_MAX_DELAY_MSEC (1000UL)
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#define BTRFS_DISCARD_MAX_IOPS (10U)
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/* Montonically decreasing minimum length filters after index 0 */
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static int discard_minlen[BTRFS_NR_DISCARD_LISTS] = {
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0,
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BTRFS_ASYNC_DISCARD_MAX_FILTER,
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BTRFS_ASYNC_DISCARD_MIN_FILTER
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};
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static struct list_head *get_discard_list(struct btrfs_discard_ctl *discard_ctl,
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struct btrfs_block_group *block_group)
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{
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return &discard_ctl->discard_list[block_group->discard_index];
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}
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static void __add_to_discard_list(struct btrfs_discard_ctl *discard_ctl,
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struct btrfs_block_group *block_group)
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{
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if (!btrfs_run_discard_work(discard_ctl))
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return;
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if (list_empty(&block_group->discard_list) ||
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block_group->discard_index == BTRFS_DISCARD_INDEX_UNUSED) {
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if (block_group->discard_index == BTRFS_DISCARD_INDEX_UNUSED)
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block_group->discard_index = BTRFS_DISCARD_INDEX_START;
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block_group->discard_eligible_time = (ktime_get_ns() +
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BTRFS_DISCARD_DELAY);
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block_group->discard_state = BTRFS_DISCARD_RESET_CURSOR;
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}
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list_move_tail(&block_group->discard_list,
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get_discard_list(discard_ctl, block_group));
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}
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static void add_to_discard_list(struct btrfs_discard_ctl *discard_ctl,
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struct btrfs_block_group *block_group)
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{
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if (!btrfs_is_block_group_data_only(block_group))
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return;
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spin_lock(&discard_ctl->lock);
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__add_to_discard_list(discard_ctl, block_group);
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spin_unlock(&discard_ctl->lock);
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}
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static void add_to_discard_unused_list(struct btrfs_discard_ctl *discard_ctl,
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struct btrfs_block_group *block_group)
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{
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spin_lock(&discard_ctl->lock);
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if (!btrfs_run_discard_work(discard_ctl)) {
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spin_unlock(&discard_ctl->lock);
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return;
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}
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list_del_init(&block_group->discard_list);
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block_group->discard_index = BTRFS_DISCARD_INDEX_UNUSED;
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block_group->discard_eligible_time = (ktime_get_ns() +
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BTRFS_DISCARD_UNUSED_DELAY);
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block_group->discard_state = BTRFS_DISCARD_RESET_CURSOR;
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list_add_tail(&block_group->discard_list,
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&discard_ctl->discard_list[BTRFS_DISCARD_INDEX_UNUSED]);
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spin_unlock(&discard_ctl->lock);
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}
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static bool remove_from_discard_list(struct btrfs_discard_ctl *discard_ctl,
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struct btrfs_block_group *block_group)
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{
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bool running = false;
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spin_lock(&discard_ctl->lock);
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if (block_group == discard_ctl->block_group) {
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running = true;
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discard_ctl->block_group = NULL;
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}
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block_group->discard_eligible_time = 0;
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list_del_init(&block_group->discard_list);
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spin_unlock(&discard_ctl->lock);
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return running;
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}
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/**
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* find_next_block_group - find block_group that's up next for discarding
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* @discard_ctl: discard control
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* @now: current time
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*
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* Iterate over the discard lists to find the next block_group up for
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* discarding checking the discard_eligible_time of block_group.
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*/
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static struct btrfs_block_group *find_next_block_group(
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struct btrfs_discard_ctl *discard_ctl,
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u64 now)
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{
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struct btrfs_block_group *ret_block_group = NULL, *block_group;
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int i;
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for (i = 0; i < BTRFS_NR_DISCARD_LISTS; i++) {
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struct list_head *discard_list = &discard_ctl->discard_list[i];
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if (!list_empty(discard_list)) {
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block_group = list_first_entry(discard_list,
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struct btrfs_block_group,
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discard_list);
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if (!ret_block_group)
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ret_block_group = block_group;
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if (ret_block_group->discard_eligible_time < now)
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break;
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if (ret_block_group->discard_eligible_time >
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block_group->discard_eligible_time)
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ret_block_group = block_group;
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}
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}
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return ret_block_group;
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}
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/**
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* peek_discard_list - wrap find_next_block_group()
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* @discard_ctl: discard control
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* @discard_state: the discard_state of the block_group after state management
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* @discard_index: the discard_index of the block_group after state management
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*
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* This wraps find_next_block_group() and sets the block_group to be in use.
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* discard_state's control flow is managed here. Variables related to
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* discard_state are reset here as needed (eg discard_cursor). @discard_state
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* and @discard_index are remembered as it may change while we're discarding,
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* but we want the discard to execute in the context determined here.
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*/
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static struct btrfs_block_group *peek_discard_list(
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struct btrfs_discard_ctl *discard_ctl,
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enum btrfs_discard_state *discard_state,
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int *discard_index)
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{
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struct btrfs_block_group *block_group;
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const u64 now = ktime_get_ns();
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spin_lock(&discard_ctl->lock);
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again:
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block_group = find_next_block_group(discard_ctl, now);
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if (block_group && now > block_group->discard_eligible_time) {
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if (block_group->discard_index == BTRFS_DISCARD_INDEX_UNUSED &&
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block_group->used != 0) {
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if (btrfs_is_block_group_data_only(block_group))
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__add_to_discard_list(discard_ctl, block_group);
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else
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list_del_init(&block_group->discard_list);
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goto again;
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}
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if (block_group->discard_state == BTRFS_DISCARD_RESET_CURSOR) {
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block_group->discard_cursor = block_group->start;
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block_group->discard_state = BTRFS_DISCARD_EXTENTS;
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}
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discard_ctl->block_group = block_group;
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*discard_state = block_group->discard_state;
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*discard_index = block_group->discard_index;
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} else {
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block_group = NULL;
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}
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spin_unlock(&discard_ctl->lock);
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return block_group;
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}
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/**
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* btrfs_discard_check_filter - updates a block groups filters
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* @block_group: block group of interest
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* @bytes: recently freed region size after coalescing
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*
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* Async discard maintains multiple lists with progressively smaller filters
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* to prioritize discarding based on size. Should a free space that matches
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* a larger filter be returned to the free_space_cache, prioritize that discard
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* by moving @block_group to the proper filter.
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*/
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void btrfs_discard_check_filter(struct btrfs_block_group *block_group,
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u64 bytes)
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{
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struct btrfs_discard_ctl *discard_ctl;
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if (!block_group ||
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!btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
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return;
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discard_ctl = &block_group->fs_info->discard_ctl;
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if (block_group->discard_index > BTRFS_DISCARD_INDEX_START &&
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bytes >= discard_minlen[block_group->discard_index - 1]) {
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int i;
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remove_from_discard_list(discard_ctl, block_group);
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for (i = BTRFS_DISCARD_INDEX_START; i < BTRFS_NR_DISCARD_LISTS;
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i++) {
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if (bytes >= discard_minlen[i]) {
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block_group->discard_index = i;
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add_to_discard_list(discard_ctl, block_group);
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break;
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}
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}
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}
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}
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/**
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* btrfs_update_discard_index - moves a block group along the discard lists
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* @discard_ctl: discard control
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* @block_group: block_group of interest
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*
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* Increment @block_group's discard_index. If it falls of the list, let it be.
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* Otherwise add it back to the appropriate list.
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*/
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static void btrfs_update_discard_index(struct btrfs_discard_ctl *discard_ctl,
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struct btrfs_block_group *block_group)
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{
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block_group->discard_index++;
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if (block_group->discard_index == BTRFS_NR_DISCARD_LISTS) {
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block_group->discard_index = 1;
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return;
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}
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add_to_discard_list(discard_ctl, block_group);
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}
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/**
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* btrfs_discard_cancel_work - remove a block_group from the discard lists
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* @discard_ctl: discard control
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* @block_group: block_group of interest
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*
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* This removes @block_group from the discard lists. If necessary, it waits on
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* the current work and then reschedules the delayed work.
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*/
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void btrfs_discard_cancel_work(struct btrfs_discard_ctl *discard_ctl,
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struct btrfs_block_group *block_group)
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{
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if (remove_from_discard_list(discard_ctl, block_group)) {
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cancel_delayed_work_sync(&discard_ctl->work);
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btrfs_discard_schedule_work(discard_ctl, true);
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}
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}
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/**
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* btrfs_discard_queue_work - handles queuing the block_groups
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* @discard_ctl: discard control
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* @block_group: block_group of interest
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*
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* This maintains the LRU order of the discard lists.
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*/
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void btrfs_discard_queue_work(struct btrfs_discard_ctl *discard_ctl,
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struct btrfs_block_group *block_group)
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{
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if (!block_group || !btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
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return;
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if (block_group->used == 0)
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add_to_discard_unused_list(discard_ctl, block_group);
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else
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add_to_discard_list(discard_ctl, block_group);
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if (!delayed_work_pending(&discard_ctl->work))
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btrfs_discard_schedule_work(discard_ctl, false);
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}
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/**
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* btrfs_discard_schedule_work - responsible for scheduling the discard work
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* @discard_ctl: discard control
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* @override: override the current timer
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*
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* Discards are issued by a delayed workqueue item. @override is used to
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* update the current delay as the baseline delay interval is reevaluated on
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* transaction commit. This is also maxed with any other rate limit.
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*/
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void btrfs_discard_schedule_work(struct btrfs_discard_ctl *discard_ctl,
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bool override)
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{
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struct btrfs_block_group *block_group;
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const u64 now = ktime_get_ns();
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spin_lock(&discard_ctl->lock);
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if (!btrfs_run_discard_work(discard_ctl))
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goto out;
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if (!override && delayed_work_pending(&discard_ctl->work))
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goto out;
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block_group = find_next_block_group(discard_ctl, now);
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if (block_group) {
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unsigned long delay = discard_ctl->delay;
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u32 kbps_limit = READ_ONCE(discard_ctl->kbps_limit);
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/*
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* A single delayed workqueue item is responsible for
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* discarding, so we can manage the bytes rate limit by keeping
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* track of the previous discard.
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*/
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if (kbps_limit && discard_ctl->prev_discard) {
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u64 bps_limit = ((u64)kbps_limit) * SZ_1K;
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u64 bps_delay = div64_u64(discard_ctl->prev_discard *
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MSEC_PER_SEC, bps_limit);
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delay = max(delay, msecs_to_jiffies(bps_delay));
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}
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/*
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* This timeout is to hopefully prevent immediate discarding
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* in a recently allocated block group.
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*/
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if (now < block_group->discard_eligible_time) {
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u64 bg_timeout = block_group->discard_eligible_time - now;
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delay = max(delay, nsecs_to_jiffies(bg_timeout));
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}
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mod_delayed_work(discard_ctl->discard_workers,
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&discard_ctl->work, delay);
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}
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out:
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spin_unlock(&discard_ctl->lock);
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}
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/**
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* btrfs_finish_discard_pass - determine next step of a block_group
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* @discard_ctl: discard control
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* @block_group: block_group of interest
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*
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* This determines the next step for a block group after it's finished going
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* through a pass on a discard list. If it is unused and fully trimmed, we can
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* mark it unused and send it to the unused_bgs path. Otherwise, pass it onto
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* the appropriate filter list or let it fall off.
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*/
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static void btrfs_finish_discard_pass(struct btrfs_discard_ctl *discard_ctl,
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struct btrfs_block_group *block_group)
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{
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remove_from_discard_list(discard_ctl, block_group);
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if (block_group->used == 0) {
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if (btrfs_is_free_space_trimmed(block_group))
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btrfs_mark_bg_unused(block_group);
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else
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add_to_discard_unused_list(discard_ctl, block_group);
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} else {
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btrfs_update_discard_index(discard_ctl, block_group);
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}
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}
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/**
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* btrfs_discard_workfn - discard work function
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* @work: work
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*
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* This finds the next block_group to start discarding and then discards a
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* single region. It does this in a two-pass fashion: first extents and second
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* bitmaps. Completely discarded block groups are sent to the unused_bgs path.
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*/
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static void btrfs_discard_workfn(struct work_struct *work)
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{
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struct btrfs_discard_ctl *discard_ctl;
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struct btrfs_block_group *block_group;
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enum btrfs_discard_state discard_state;
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int discard_index = 0;
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u64 trimmed = 0;
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u64 minlen = 0;
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discard_ctl = container_of(work, struct btrfs_discard_ctl, work.work);
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block_group = peek_discard_list(discard_ctl, &discard_state,
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&discard_index);
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if (!block_group || !btrfs_run_discard_work(discard_ctl))
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return;
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/* Perform discarding */
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minlen = discard_minlen[discard_index];
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if (discard_state == BTRFS_DISCARD_BITMAPS) {
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u64 maxlen = 0;
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/*
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* Use the previous levels minimum discard length as the max
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* length filter. In the case something is added to make a
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* region go beyond the max filter, the entire bitmap is set
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* back to BTRFS_TRIM_STATE_UNTRIMMED.
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*/
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if (discard_index != BTRFS_DISCARD_INDEX_UNUSED)
|
|
maxlen = discard_minlen[discard_index - 1];
|
|
|
|
btrfs_trim_block_group_bitmaps(block_group, &trimmed,
|
|
block_group->discard_cursor,
|
|
btrfs_block_group_end(block_group),
|
|
minlen, maxlen, true);
|
|
discard_ctl->discard_bitmap_bytes += trimmed;
|
|
} else {
|
|
btrfs_trim_block_group_extents(block_group, &trimmed,
|
|
block_group->discard_cursor,
|
|
btrfs_block_group_end(block_group),
|
|
minlen, true);
|
|
discard_ctl->discard_extent_bytes += trimmed;
|
|
}
|
|
|
|
discard_ctl->prev_discard = trimmed;
|
|
|
|
/* Determine next steps for a block_group */
|
|
if (block_group->discard_cursor >= btrfs_block_group_end(block_group)) {
|
|
if (discard_state == BTRFS_DISCARD_BITMAPS) {
|
|
btrfs_finish_discard_pass(discard_ctl, block_group);
|
|
} else {
|
|
block_group->discard_cursor = block_group->start;
|
|
spin_lock(&discard_ctl->lock);
|
|
if (block_group->discard_state !=
|
|
BTRFS_DISCARD_RESET_CURSOR)
|
|
block_group->discard_state =
|
|
BTRFS_DISCARD_BITMAPS;
|
|
spin_unlock(&discard_ctl->lock);
|
|
}
|
|
}
|
|
|
|
spin_lock(&discard_ctl->lock);
|
|
discard_ctl->block_group = NULL;
|
|
spin_unlock(&discard_ctl->lock);
|
|
|
|
btrfs_discard_schedule_work(discard_ctl, false);
|
|
}
|
|
|
|
/**
|
|
* btrfs_run_discard_work - determines if async discard should be running
|
|
* @discard_ctl: discard control
|
|
*
|
|
* Checks if the file system is writeable and BTRFS_FS_DISCARD_RUNNING is set.
|
|
*/
|
|
bool btrfs_run_discard_work(struct btrfs_discard_ctl *discard_ctl)
|
|
{
|
|
struct btrfs_fs_info *fs_info = container_of(discard_ctl,
|
|
struct btrfs_fs_info,
|
|
discard_ctl);
|
|
|
|
return (!(fs_info->sb->s_flags & SB_RDONLY) &&
|
|
test_bit(BTRFS_FS_DISCARD_RUNNING, &fs_info->flags));
|
|
}
|
|
|
|
/**
|
|
* btrfs_discard_calc_delay - recalculate the base delay
|
|
* @discard_ctl: discard control
|
|
*
|
|
* Recalculate the base delay which is based off the total number of
|
|
* discardable_extents. Clamp this between the lower_limit (iops_limit or 1ms)
|
|
* and the upper_limit (BTRFS_DISCARD_MAX_DELAY_MSEC).
|
|
*/
|
|
void btrfs_discard_calc_delay(struct btrfs_discard_ctl *discard_ctl)
|
|
{
|
|
s32 discardable_extents;
|
|
s64 discardable_bytes;
|
|
u32 iops_limit;
|
|
unsigned long delay;
|
|
unsigned long lower_limit = BTRFS_DISCARD_MIN_DELAY_MSEC;
|
|
|
|
discardable_extents = atomic_read(&discard_ctl->discardable_extents);
|
|
if (!discardable_extents)
|
|
return;
|
|
|
|
spin_lock(&discard_ctl->lock);
|
|
|
|
/*
|
|
* The following is to fix a potential -1 discrepenancy that we're not
|
|
* sure how to reproduce. But given that this is the only place that
|
|
* utilizes these numbers and this is only called by from
|
|
* btrfs_finish_extent_commit() which is synchronized, we can correct
|
|
* here.
|
|
*/
|
|
if (discardable_extents < 0)
|
|
atomic_add(-discardable_extents,
|
|
&discard_ctl->discardable_extents);
|
|
|
|
discardable_bytes = atomic64_read(&discard_ctl->discardable_bytes);
|
|
if (discardable_bytes < 0)
|
|
atomic64_add(-discardable_bytes,
|
|
&discard_ctl->discardable_bytes);
|
|
|
|
if (discardable_extents <= 0) {
|
|
spin_unlock(&discard_ctl->lock);
|
|
return;
|
|
}
|
|
|
|
iops_limit = READ_ONCE(discard_ctl->iops_limit);
|
|
if (iops_limit)
|
|
lower_limit = max_t(unsigned long, lower_limit,
|
|
MSEC_PER_SEC / iops_limit);
|
|
|
|
delay = BTRFS_DISCARD_TARGET_MSEC / discardable_extents;
|
|
delay = clamp(delay, lower_limit, BTRFS_DISCARD_MAX_DELAY_MSEC);
|
|
discard_ctl->delay = msecs_to_jiffies(delay);
|
|
|
|
spin_unlock(&discard_ctl->lock);
|
|
}
|
|
|
|
/**
|
|
* btrfs_discard_update_discardable - propagate discard counters
|
|
* @block_group: block_group of interest
|
|
* @ctl: free_space_ctl of @block_group
|
|
*
|
|
* This propagates deltas of counters up to the discard_ctl. It maintains a
|
|
* current counter and a previous counter passing the delta up to the global
|
|
* stat. Then the current counter value becomes the previous counter value.
|
|
*/
|
|
void btrfs_discard_update_discardable(struct btrfs_block_group *block_group,
|
|
struct btrfs_free_space_ctl *ctl)
|
|
{
|
|
struct btrfs_discard_ctl *discard_ctl;
|
|
s32 extents_delta;
|
|
s64 bytes_delta;
|
|
|
|
if (!block_group ||
|
|
!btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC) ||
|
|
!btrfs_is_block_group_data_only(block_group))
|
|
return;
|
|
|
|
discard_ctl = &block_group->fs_info->discard_ctl;
|
|
|
|
extents_delta = ctl->discardable_extents[BTRFS_STAT_CURR] -
|
|
ctl->discardable_extents[BTRFS_STAT_PREV];
|
|
if (extents_delta) {
|
|
atomic_add(extents_delta, &discard_ctl->discardable_extents);
|
|
ctl->discardable_extents[BTRFS_STAT_PREV] =
|
|
ctl->discardable_extents[BTRFS_STAT_CURR];
|
|
}
|
|
|
|
bytes_delta = ctl->discardable_bytes[BTRFS_STAT_CURR] -
|
|
ctl->discardable_bytes[BTRFS_STAT_PREV];
|
|
if (bytes_delta) {
|
|
atomic64_add(bytes_delta, &discard_ctl->discardable_bytes);
|
|
ctl->discardable_bytes[BTRFS_STAT_PREV] =
|
|
ctl->discardable_bytes[BTRFS_STAT_CURR];
|
|
}
|
|
}
|
|
|
|
/**
|
|
* btrfs_discard_punt_unused_bgs_list - punt unused_bgs list to discard lists
|
|
* @fs_info: fs_info of interest
|
|
*
|
|
* The unused_bgs list needs to be punted to the discard lists because the
|
|
* order of operations is changed. In the normal sychronous discard path, the
|
|
* block groups are trimmed via a single large trim in transaction commit. This
|
|
* is ultimately what we are trying to avoid with asynchronous discard. Thus,
|
|
* it must be done before going down the unused_bgs path.
|
|
*/
|
|
void btrfs_discard_punt_unused_bgs_list(struct btrfs_fs_info *fs_info)
|
|
{
|
|
struct btrfs_block_group *block_group, *next;
|
|
|
|
spin_lock(&fs_info->unused_bgs_lock);
|
|
/* We enabled async discard, so punt all to the queue */
|
|
list_for_each_entry_safe(block_group, next, &fs_info->unused_bgs,
|
|
bg_list) {
|
|
list_del_init(&block_group->bg_list);
|
|
btrfs_discard_queue_work(&fs_info->discard_ctl, block_group);
|
|
}
|
|
spin_unlock(&fs_info->unused_bgs_lock);
|
|
}
|
|
|
|
/**
|
|
* btrfs_discard_purge_list - purge discard lists
|
|
* @discard_ctl: discard control
|
|
*
|
|
* If we are disabling async discard, we may have intercepted block groups that
|
|
* are completely free and ready for the unused_bgs path. As discarding will
|
|
* now happen in transaction commit or not at all, we can safely mark the
|
|
* corresponding block groups as unused and they will be sent on their merry
|
|
* way to the unused_bgs list.
|
|
*/
|
|
static void btrfs_discard_purge_list(struct btrfs_discard_ctl *discard_ctl)
|
|
{
|
|
struct btrfs_block_group *block_group, *next;
|
|
int i;
|
|
|
|
spin_lock(&discard_ctl->lock);
|
|
for (i = 0; i < BTRFS_NR_DISCARD_LISTS; i++) {
|
|
list_for_each_entry_safe(block_group, next,
|
|
&discard_ctl->discard_list[i],
|
|
discard_list) {
|
|
list_del_init(&block_group->discard_list);
|
|
spin_unlock(&discard_ctl->lock);
|
|
if (block_group->used == 0)
|
|
btrfs_mark_bg_unused(block_group);
|
|
spin_lock(&discard_ctl->lock);
|
|
}
|
|
}
|
|
spin_unlock(&discard_ctl->lock);
|
|
}
|
|
|
|
void btrfs_discard_resume(struct btrfs_fs_info *fs_info)
|
|
{
|
|
if (!btrfs_test_opt(fs_info, DISCARD_ASYNC)) {
|
|
btrfs_discard_cleanup(fs_info);
|
|
return;
|
|
}
|
|
|
|
btrfs_discard_punt_unused_bgs_list(fs_info);
|
|
|
|
set_bit(BTRFS_FS_DISCARD_RUNNING, &fs_info->flags);
|
|
}
|
|
|
|
void btrfs_discard_stop(struct btrfs_fs_info *fs_info)
|
|
{
|
|
clear_bit(BTRFS_FS_DISCARD_RUNNING, &fs_info->flags);
|
|
}
|
|
|
|
void btrfs_discard_init(struct btrfs_fs_info *fs_info)
|
|
{
|
|
struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
|
|
int i;
|
|
|
|
spin_lock_init(&discard_ctl->lock);
|
|
INIT_DELAYED_WORK(&discard_ctl->work, btrfs_discard_workfn);
|
|
|
|
for (i = 0; i < BTRFS_NR_DISCARD_LISTS; i++)
|
|
INIT_LIST_HEAD(&discard_ctl->discard_list[i]);
|
|
|
|
discard_ctl->prev_discard = 0;
|
|
atomic_set(&discard_ctl->discardable_extents, 0);
|
|
atomic64_set(&discard_ctl->discardable_bytes, 0);
|
|
discard_ctl->max_discard_size = BTRFS_ASYNC_DISCARD_DEFAULT_MAX_SIZE;
|
|
discard_ctl->delay = BTRFS_DISCARD_MAX_DELAY_MSEC;
|
|
discard_ctl->iops_limit = BTRFS_DISCARD_MAX_IOPS;
|
|
discard_ctl->kbps_limit = 0;
|
|
discard_ctl->discard_extent_bytes = 0;
|
|
discard_ctl->discard_bitmap_bytes = 0;
|
|
atomic64_set(&discard_ctl->discard_bytes_saved, 0);
|
|
}
|
|
|
|
void btrfs_discard_cleanup(struct btrfs_fs_info *fs_info)
|
|
{
|
|
btrfs_discard_stop(fs_info);
|
|
cancel_delayed_work_sync(&fs_info->discard_ctl.work);
|
|
btrfs_discard_purge_list(&fs_info->discard_ctl);
|
|
}
|