// SPDX-License-Identifier: GPL-2.0
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/list.h>
#include <linux/math64.h>
#include <linux/sizes.h>
#include <linux/workqueue.h>
#include "ctree.h"
#include "block-group.h"
#include "discard.h"
#include "free-space-cache.h"
#include "fs.h"
/*
* This contains the logic to handle async discard.
*
* Async discard manages trimming of free space outside of transaction commit.
* Discarding is done by managing the block_groups on a LRU list based on free
* space recency. Two passes are used to first prioritize discarding extents
* and then allow for trimming in the bitmap the best opportunity to coalesce.
* The block_groups are maintained on multiple lists to allow for multiple
* passes with different discard filter requirements. A delayed work item is
* used to manage discarding with timeout determined by a max of the delay
* incurred by the iops rate limit, the byte rate limit, and the max delay of
* BTRFS_DISCARD_MAX_DELAY.
*
* Note, this only keeps track of block_groups that are explicitly for data.
* Mixed block_groups are not supported.
*
* The first list is special to manage discarding of fully free block groups.
* This is necessary because we issue a final trim for a full free block group
* after forgetting it. When a block group becomes unused, instead of directly
* being added to the unused_bgs list, we add it to this first list. Then
* from there, if it becomes fully discarded, we place it onto the unused_bgs
* list.
*
* The in-memory free space cache serves as the backing state for discard.
* Consequently this means there is no persistence. We opt to load all the
* block groups in as not discarded, so the mount case degenerates to the
* crashing case.
*
* As the free space cache uses bitmaps, there exists a tradeoff between
* ease/efficiency for find_free_extent() and the accuracy of discard state.
* Here we opt to let untrimmed regions merge with everything while only letting
* trimmed regions merge with other trimmed regions. This can cause
* overtrimming, but the coalescing benefit seems to be worth it. Additionally,
* bitmap state is tracked as a whole. If we're able to fully trim a bitmap,
* the trimmed flag is set on the bitmap. Otherwise, if an allocation comes in,
* this resets the state and we will retry trimming the whole bitmap. This is a
* tradeoff between discard state accuracy and the cost of accounting.
*/
/* This is an initial delay to give some chance for block reuse */
#define BTRFS_DISCARD_DELAY (120ULL * NSEC_PER_SEC)
#define BTRFS_DISCARD_UNUSED_DELAY (10ULL * NSEC_PER_SEC)
#define BTRFS_DISCARD_MIN_DELAY_MSEC (1UL)
#define BTRFS_DISCARD_MAX_DELAY_MSEC (1000UL)
#define BTRFS_DISCARD_MAX_IOPS (1000U)
/* Monotonically decreasing minimum length filters after index 0 */
static int discard_minlen[BTRFS_NR_DISCARD_LISTS] = {
0,
BTRFS_ASYNC_DISCARD_MAX_FILTER,
BTRFS_ASYNC_DISCARD_MIN_FILTER
};
static struct list_head *get_discard_list(struct btrfs_discard_ctl *discard_ctl,
const struct btrfs_block_group *block_group)
{
return &discard_ctl->discard_list[block_group->discard_index];
}
/*
* Determine if async discard should be running.
*
* @discard_ctl: discard control
*
* Check if the file system is writeable and BTRFS_FS_DISCARD_RUNNING is set.
*/
static bool btrfs_run_discard_work(const 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));
}
static void __add_to_discard_list(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group)
{
lockdep_assert_held(&discard_ctl->lock);
if (!btrfs_run_discard_work(discard_ctl))
return;
if (list_empty(&block_group->discard_list) ||
block_group->discard_index == BTRFS_DISCARD_INDEX_UNUSED) {
if (block_group->discard_index == BTRFS_DISCARD_INDEX_UNUSED)
block_group->discard_index = BTRFS_DISCARD_INDEX_START;
block_group->discard_eligible_time = (ktime_get_ns() +
BTRFS_DISCARD_DELAY);
block_group->discard_state = BTRFS_DISCARD_RESET_CURSOR;
}
if (list_empty(&block_group->discard_list))
btrfs_get_block_group(block_group);
list_move_tail(&block_group->discard_list,
get_discard_list(discard_ctl, block_group));
}
static void add_to_discard_list(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group)
{
if (!btrfs_is_block_group_data_only(block_group))
return;
spin_lock(&discard_ctl->lock);
__add_to_discard_list(discard_ctl, block_group);
spin_unlock(&discard_ctl->lock);
}
static void add_to_discard_unused_list(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group)
{
bool queued;
spin_lock(&discard_ctl->lock);
queued = !list_empty(&block_group->discard_list);
if (!btrfs_run_discard_work(discard_ctl)) {
spin_unlock(&discard_ctl->lock);
return;
}
list_del_init(&block_group->discard_list);
block_group->discard_index = BTRFS_DISCARD_INDEX_UNUSED;
block_group->discard_eligible_time = (ktime_get_ns() +
BTRFS_DISCARD_UNUSED_DELAY);
block_group->discard_state = BTRFS_DISCARD_RESET_CURSOR;
if (!queued)
btrfs_get_block_group(block_group);
list_add_tail(&block_group->discard_list,
&discard_ctl->discard_list[BTRFS_DISCARD_INDEX_UNUSED]);
spin_unlock(&discard_ctl->lock);
}
static bool remove_from_discard_list(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group)
{
bool running = false;
bool queued = false;
spin_lock(&discard_ctl->lock);
if (block_group == discard_ctl->block_group) {
running = true;
discard_ctl->block_group = NULL;
}
block_group->discard_eligible_time = 0;
queued = !list_empty(&block_group->discard_list);
list_del_init(&block_group->discard_list);
/*
* If the block group is currently running in the discard workfn, we
* don't want to deref it, since it's still being used by the workfn.
* The workfn will notice this case and deref the block group when it is
* finished.
*/
if (queued && !running)
btrfs_put_block_group(block_group);
spin_unlock(&discard_ctl->lock);
return running;
}
/*
* Find block_group that's up next for discarding.
*
* @discard_ctl: discard control
* @now: current time
*
* Iterate over the discard lists to find the next block_group up for
* discarding checking the discard_eligible_time of block_group.
*/
static struct btrfs_block_group *find_next_block_group(
struct btrfs_discard_ctl *discard_ctl,
u64 now)
{
struct btrfs_block_group *ret_block_group = NULL, *block_group;
int i;
for (i = 0; i < BTRFS_NR_DISCARD_LISTS; i++) {
struct list_head *discard_list = &discard_ctl->discard_list[i];
if (!list_empty(discard_list)) {
block_group = list_first_entry(discard_list,
struct btrfs_block_group,
discard_list);
if (!ret_block_group)
ret_block_group = block_group;
if (ret_block_group->discard_eligible_time < now)
break;
if (ret_block_group->discard_eligible_time >
block_group->discard_eligible_time)
ret_block_group = block_group;
}
}
return ret_block_group;
}
/*
* Look up next block group and set it for use.
*
* @discard_ctl: discard control
* @discard_state: the discard_state of the block_group after state management
* @discard_index: the discard_index of the block_group after state management
* @now: time when discard was invoked, in ns
*
* Wrap find_next_block_group() and set the block_group to be in use.
* @discard_state's control flow is managed here. Variables related to
* @discard_state are reset here as needed (eg. @discard_cursor). @discard_state
* and @discard_index are remembered as it may change while we're discarding,
* but we want the discard to execute in the context determined here.
*/
static struct btrfs_block_group *peek_discard_list(
struct btrfs_discard_ctl *discard_ctl,
enum btrfs_discard_state *discard_state,
int *discard_index, u64 now)
{
struct btrfs_block_group *block_group;
spin_lock(&discard_ctl->lock);
again:
block_group = find_next_block_group(discard_ctl, now);
if (block_group && now >= block_group->discard_eligible_time) {
if (block_group->discard_index == BTRFS_DISCARD_INDEX_UNUSED &&
block_group->used != 0) {
if (btrfs_is_block_group_data_only(block_group)) {
__add_to_discard_list(discard_ctl, block_group);
} else {
list_del_init(&block_group->discard_list);
btrfs_put_block_group(block_group);
}
goto again;
}
if (block_group->discard_state == BTRFS_DISCARD_RESET_CURSOR) {
block_group->discard_cursor = block_group->start;
block_group->discard_state = BTRFS_DISCARD_EXTENTS;
}
discard_ctl->block_group = block_group;
}
if (block_group) {
*discard_state = block_group->discard_state;
*discard_index = block_group->discard_index;
}
spin_unlock(&discard_ctl->lock);
return block_group;
}
/*
* Update a block group's filters.
*
* @block_group: block group of interest
* @bytes: recently freed region size after coalescing
*
* Async discard maintains multiple lists with progressively smaller filters
* to prioritize discarding based on size. Should a free space that matches
* a larger filter be returned to the free_space_cache, prioritize that discard
* by moving @block_group to the proper filter.
*/
void btrfs_discard_check_filter(struct btrfs_block_group *block_group,
u64 bytes)
{
struct btrfs_discard_ctl *discard_ctl;
if (!block_group ||
!btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
return;
discard_ctl = &block_group->fs_info->discard_ctl;
if (block_group->discard_index > BTRFS_DISCARD_INDEX_START &&
bytes >= discard_minlen[block_group->discard_index - 1]) {
int i;
remove_from_discard_list(discard_ctl, block_group);
for (i = BTRFS_DISCARD_INDEX_START; i < BTRFS_NR_DISCARD_LISTS;
i++) {
if (bytes >= discard_minlen[i]) {
block_group->discard_index = i;
add_to_discard_list(discard_ctl, block_group);
break;
}
}
}
}
/*
* Move a block group along the discard lists.
*
* @discard_ctl: discard control
* @block_group: block_group of interest
*
* Increment @block_group's discard_index. If it falls of the list, let it be.
* Otherwise add it back to the appropriate list.
*/
static void btrfs_update_discard_index(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group)
{
block_group->discard_index++;
if (block_group->discard_index == BTRFS_NR_DISCARD_LISTS) {
block_group->discard_index = 1;
return;
}
add_to_discard_list(discard_ctl, block_group);
}
/*
* Remove a block_group from the discard lists.
*
* @discard_ctl: discard control
* @block_group: block_group of interest
*
* Remove @block_group from the discard lists. If necessary, wait on the
* current work and then reschedule the delayed work.
*/
void btrfs_discard_cancel_work(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group)
{
if (remove_from_discard_list(discard_ctl, block_group)) {
cancel_delayed_work_sync(&discard_ctl->work);
btrfs_discard_schedule_work(discard_ctl, true);
}
}
/*
* Handles queuing the block_groups.
*
* @discard_ctl: discard control
* @block_group: block_group of interest
*
* Maintain the LRU order of the discard lists.
*/
void btrfs_discard_queue_work(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group)
{
if (!block_group || !btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
return;
if (block_group->used == 0)
add_to_discard_unused_list(discard_ctl, block_group);
else
add_to_discard_list(discard_ctl, block_group);
if (!delayed_work_pending(&discard_ctl->work))
btrfs_discard_schedule_work(discard_ctl, false);
}
static void __btrfs_discard_schedule_work(struct btrfs_discard_ctl *discard_ctl,
u64 now, bool override)
{
struct btrfs_block_group *block_group;
if (!btrfs_run_discard_work(discard_ctl))
return;
if (!override && delayed_work_pending(&discard_ctl->work))
return;
block_group = find_next_block_group(discard_ctl, now);
if (block_group) {
u64 delay = discard_ctl->delay_ms * NSEC_PER_MSEC;
u32 kbps_limit = READ_ONCE(discard_ctl->kbps_limit);
/*
* A single delayed workqueue item is responsible for
* discarding, so we can manage the bytes rate limit by keeping
* track of the previous discard.
*/
if (kbps_limit && discard_ctl->prev_discard) {
u64 bps_limit = ((u64)kbps_limit) * SZ_1K;
u64 bps_delay = div64_u64(discard_ctl->prev_discard *
NSEC_PER_SEC, bps_limit);
delay = max(delay, bps_delay);
}
/*
* This timeout is to hopefully prevent immediate discarding
* in a recently allocated block group.
*/
if (now < block_group->discard_eligible_time) {
u64 bg_timeout = block_group->discard_eligible_time - now;
delay = max(delay, bg_timeout);
}
if (override && discard_ctl->prev_discard) {
u64 elapsed = now - discard_ctl->prev_discard_time;
if (delay > elapsed)
delay -= elapsed;
else
delay = 0;
}
mod_delayed_work(discard_ctl->discard_workers,
&discard_ctl->work, nsecs_to_jiffies(delay));
}
}
/*
* Responsible for scheduling the discard work.
*
* @discard_ctl: discard control
* @override: override the current timer
*
* Discards are issued by a delayed workqueue item. @override is used to
* update the current delay as the baseline delay interval is reevaluated on
* transaction commit. This is also maxed with any other rate limit.
*/
void btrfs_discard_schedule_work(struct btrfs_discard_ctl *discard_ctl,
bool override)
{
const u64 now = ktime_get_ns();
spin_lock(&discard_ctl->lock);
__btrfs_discard_schedule_work(discard_ctl, now, override);
spin_unlock(&discard_ctl->lock);
}
/*
* Determine next step of a block_group.
*
* @discard_ctl: discard control
* @block_group: block_group of interest
*
* Determine the next step for a block group after it's finished going through
* a pass on a discard list. If it is unused and fully trimmed, we can mark it
* unused and send it to the unused_bgs path. Otherwise, pass it onto the
* appropriate filter list or let it fall off.
*/
static void btrfs_finish_discard_pass(struct btrfs_discard_ctl *discard_ctl,
struct btrfs_block_group *block_group)
{
remove_from_discard_list(discard_ctl, block_group);
if (block_group->used == 0) {
if (btrfs_is_free_space_trimmed(block_group))
btrfs_mark_bg_unused(block_group);
else
add_to_discard_unused_list(discard_ctl, block_group);
} else {
btrfs_update_discard_index(discard_ctl, block_group);
}
}
/*
* Discard work queue callback
*
* @work: work
*
* Find the next block_group to start discarding and then discard a single
* region. It does this in a two-pass fashion: first extents and second
* bitmaps. Completely discarded block groups are sent to the unused_bgs path.
*/
static void btrfs_discard_workfn(struct work_struct *work)
{
struct btrfs_discard_ctl *discard_ctl;
struct btrfs_block_group *block_group;
enum btrfs_discard_state discard_state;
int discard_index = 0;
u64 trimmed = 0;
u64 minlen = 0;
u64 now = ktime_get_ns();
discard_ctl = container_of(work, struct btrfs_discard_ctl, work.work);
block_group = peek_discard_list(discard_ctl, &discard_state,
&discard_index, now);
if (!block_group || !btrfs_run_discard_work(discard_ctl))
return;
if (now < block_group->discard_eligible_time) {
btrfs_discard_schedule_work(discard_ctl, false);
return;
}
/* Perform discarding */
minlen = discard_minlen[discard_index];
if (discard_state == BTRFS_DISCARD_BITMAPS) {
u64 maxlen = 0;
/*
* Use the previous levels minimum discard length as the max
* length filter. In the case something is added to make a
* region go beyond the max filter, the entire bitmap is set
* back to BTRFS_TRIM_STATE_UNTRIMMED.
*/
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;
}
/* 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);
}
}
now = ktime_get_ns();
spin_lock(&discard_ctl->lock);
discard_ctl->prev_discard = trimmed;
discard_ctl->prev_discard_time = now;
/*
* If the block group was removed from the discard list while it was
* running in this workfn, then we didn't deref it, since this function
* still owned that reference. But we set the discard_ctl->block_group
* back to NULL, so we can use that condition to know that now we need
* to deref the block_group.
*/
if (discard_ctl->block_group == NULL)
btrfs_put_block_group(block_group);
discard_ctl->block_group = NULL;
__btrfs_discard_schedule_work(discard_ctl, now, false);
spin_unlock(&discard_ctl->lock);
}
/*
* 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 min_delay = BTRFS_DISCARD_MIN_DELAY_MSEC;
unsigned long delay;
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 discrepancy 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) {
delay = MSEC_PER_SEC / iops_limit;
} else {
/*
* Unset iops_limit means go as fast as possible, so allow a
* delay of 0.
*/
delay = 0;
min_delay = 0;
}
delay = clamp(delay, min_delay, BTRFS_DISCARD_MAX_DELAY_MSEC);
discard_ctl->delay_ms = delay;
spin_unlock(&discard_ctl->lock);
}
/*
* Propagate discard counters.
*
* @block_group: block_group of interest
*
* Propagate 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;
ctl = block_group->free_space_ctl;
discard_ctl = &block_group->fs_info->discard_ctl;
lockdep_assert_held(&ctl->tree_lock);
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];
}
}
/*
* 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 synchronous 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);
/*
* This put is for the get done by btrfs_mark_bg_unused.
* Queueing discard incremented it for discard's reference.
*/
btrfs_put_block_group(block_group);
}
spin_unlock(&fs_info->unused_bgs_lock);
}
/*
* 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);
btrfs_put_block_group(block_group);
}
}
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;
discard_ctl->prev_discard_time = 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_ms = 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);
}
Codebase Browser
linux