Skip to content

Commit

Permalink
btrfs: scrub: introduce helper to queue a stripe for scrub
Browse files Browse the repository at this point in the history 
The new helper, queue_scrub_stripe(), would try to queue a stripe for
scrub.  If all stripes are already in use, we will submit all the
existing ones and wait for them to finish.

Currently we would queue up to 8 stripes, to enlarge the blocksize to
512KiB to improve the performance. Sectors repaired on zoned need to be
relocated instead of in-place fix.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
  • Loading branch information
Qu Wenruo authored and David Sterba committed Apr 17, 2023
1 parent 0096580 commit 5476539
Show file tree
Hide file tree
Showing 2 changed files with 181 additions and 17 deletions.
185 changes: 177 additions & 8 deletions fs/btrfs/scrub.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@ struct scrub_ctx;
*/
#define SCRUB_SECTORS_PER_BIO 32 /* 128KiB per bio for 4KiB pages */
#define SCRUB_BIOS_PER_SCTX 64 /* 8MiB per device in flight for 4KiB pages */
#define SCRUB_STRIPES_PER_SCTX 8 /* That would be 8 64K stripe per-device. */

/*
* The following value times PAGE_SIZE needs to be large enough to match the
Expand Down Expand Up @@ -277,9 +278,11 @@ struct scrub_parity {

struct scrub_ctx {
struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
struct scrub_stripe stripes[SCRUB_STRIPES_PER_SCTX];
struct btrfs_fs_info *fs_info;
int first_free;
int curr;
int cur_stripe;
atomic_t bios_in_flight;
atomic_t workers_pending;
spinlock_t list_lock;
Expand Down Expand Up @@ -389,7 +392,8 @@ static void release_scrub_stripe(struct scrub_stripe *stripe)
stripe->state = 0;
}

int init_scrub_stripe(struct btrfs_fs_info *fs_info, struct scrub_stripe *stripe)
static int init_scrub_stripe(struct btrfs_fs_info *fs_info,
struct scrub_stripe *stripe)
{
int ret;

Expand Down Expand Up @@ -895,6 +899,9 @@ static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
kfree(sbio);
}

for (i = 0; i < SCRUB_STRIPES_PER_SCTX; i++)
release_scrub_stripe(&sctx->stripes[i]);

kfree(sctx->wr_curr_bio);
scrub_free_csums(sctx);
kfree(sctx);
Expand Down Expand Up @@ -939,6 +946,14 @@ static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
else
sctx->bios[i]->next_free = -1;
}
for (i = 0; i < SCRUB_STRIPES_PER_SCTX; i++) {
int ret;

ret = init_scrub_stripe(fs_info, &sctx->stripes[i]);
if (ret < 0)
goto nomem;
sctx->stripes[i].sctx = sctx;
}
sctx->first_free = 0;
atomic_set(&sctx->bios_in_flight, 0);
atomic_set(&sctx->workers_pending, 0);
Expand Down Expand Up @@ -2668,7 +2683,7 @@ static void scrub_stripe_read_repair_worker(struct work_struct *work)
wake_up(&stripe->repair_wait);
}

void scrub_read_endio(struct btrfs_bio *bbio)
static void scrub_read_endio(struct btrfs_bio *bbio)
{
struct scrub_stripe *stripe = bbio->private;

Expand Down Expand Up @@ -2725,8 +2740,8 @@ static void scrub_write_endio(struct btrfs_bio *bbio)
*
* - Handle dev-replace and read-repair writeback differently
*/
void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *stripe,
unsigned long write_bitmap, bool dev_replace)
static void scrub_write_sectors(struct scrub_ctx *sctx, struct scrub_stripe *stripe,
unsigned long write_bitmap, bool dev_replace)
{
struct btrfs_fs_info *fs_info = stripe->bg->fs_info;
struct btrfs_bio *bbio = NULL;
Expand Down Expand Up @@ -4294,10 +4309,11 @@ static void scrub_stripe_reset_bitmaps(struct scrub_stripe *stripe)
* Return >0 if there is no such stripe in the specified range.
* Return <0 for error.
*/
int scrub_find_fill_first_stripe(struct btrfs_block_group *bg,
struct btrfs_device *dev, u64 physical,
int mirror_num, u64 logical_start,
u32 logical_len, struct scrub_stripe *stripe)
static int scrub_find_fill_first_stripe(struct btrfs_block_group *bg,
struct btrfs_device *dev, u64 physical,
int mirror_num, u64 logical_start,
u32 logical_len,
struct scrub_stripe *stripe)
{
struct btrfs_fs_info *fs_info = bg->fs_info;
struct btrfs_root *extent_root = btrfs_extent_root(fs_info, bg->start);
Expand Down Expand Up @@ -4406,6 +4422,159 @@ int scrub_find_fill_first_stripe(struct btrfs_block_group *bg,
return ret;
}

static void scrub_reset_stripe(struct scrub_stripe *stripe)
{
scrub_stripe_reset_bitmaps(stripe);

stripe->nr_meta_extents = 0;
stripe->nr_data_extents = 0;
stripe->state = 0;

for (int i = 0; i < stripe->nr_sectors; i++) {
stripe->sectors[i].is_metadata = false;
stripe->sectors[i].csum = NULL;
stripe->sectors[i].generation = 0;
}
}

static void scrub_submit_initial_read(struct scrub_ctx *sctx,
struct scrub_stripe *stripe)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_bio *bbio;
int mirror = stripe->mirror_num;

ASSERT(stripe->bg);
ASSERT(stripe->mirror_num > 0);
ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &stripe->state));

bbio = btrfs_bio_alloc(SCRUB_STRIPE_PAGES, REQ_OP_READ, fs_info,
scrub_read_endio, stripe);

/* Read the whole stripe. */
bbio->bio.bi_iter.bi_sector = stripe->logical >> SECTOR_SHIFT;
for (int i = 0; i < BTRFS_STRIPE_LEN >> PAGE_SHIFT; i++) {
int ret;

ret = bio_add_page(&bbio->bio, stripe->pages[i], PAGE_SIZE, 0);
/* We should have allocated enough bio vectors. */
ASSERT(ret == PAGE_SIZE);
}
atomic_inc(&stripe->pending_io);

/*
* For dev-replace, either user asks to avoid the source dev, or
* the device is missing, we try the next mirror instead.
*/
if (sctx->is_dev_replace &&
(fs_info->dev_replace.cont_reading_from_srcdev_mode ==
BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID ||
!stripe->dev->bdev)) {
int num_copies = btrfs_num_copies(fs_info, stripe->bg->start,
stripe->bg->length);

mirror = calc_next_mirror(mirror, num_copies);
}
btrfs_submit_bio(bbio, mirror);
}

static void flush_scrub_stripes(struct scrub_ctx *sctx)
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct scrub_stripe *stripe;
const int nr_stripes = sctx->cur_stripe;

if (!nr_stripes)
return;

ASSERT(test_bit(SCRUB_STRIPE_FLAG_INITIALIZED, &sctx->stripes[0].state));
for (int i = 0; i < nr_stripes; i++) {
stripe = &sctx->stripes[i];
scrub_submit_initial_read(sctx, stripe);
}

for (int i = 0; i < nr_stripes; i++) {
stripe = &sctx->stripes[i];

wait_event(stripe->repair_wait,
test_bit(SCRUB_STRIPE_FLAG_REPAIR_DONE, &stripe->state));
}

/*
* Submit the repaired sectors. For zoned case, we cannot do repair
* in-place, but queue the bg to be relocated.
*/
if (btrfs_is_zoned(fs_info)) {
for (int i = 0; i < nr_stripes; i++) {
stripe = &sctx->stripes[i];

if (!bitmap_empty(&stripe->error_bitmap, stripe->nr_sectors)) {
btrfs_repair_one_zone(fs_info,
sctx->stripes[0].bg->start);
break;
}
}
} else {
for (int i = 0; i < nr_stripes; i++) {
unsigned long repaired;

stripe = &sctx->stripes[i];

bitmap_andnot(&repaired, &stripe->init_error_bitmap,
&stripe->error_bitmap, stripe->nr_sectors);
scrub_write_sectors(sctx, stripe, repaired, false);
}
}

/* Submit for dev-replace. */
if (sctx->is_dev_replace) {
for (int i = 0; i < nr_stripes; i++) {
unsigned long good;

stripe = &sctx->stripes[i];

ASSERT(stripe->dev == fs_info->dev_replace.srcdev);

bitmap_andnot(&good, &stripe->extent_sector_bitmap,
&stripe->error_bitmap, stripe->nr_sectors);
scrub_write_sectors(sctx, stripe, good, true);
}
}

/* Wait for the above writebacks to finish. */
for (int i = 0; i < nr_stripes; i++) {
stripe = &sctx->stripes[i];

wait_scrub_stripe_io(stripe);
scrub_reset_stripe(stripe);
}
sctx->cur_stripe = 0;
}

int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *bg,
struct btrfs_device *dev, int mirror_num,
u64 logical, u32 length, u64 physical)
{
struct scrub_stripe *stripe;
int ret;

/* No available slot, submit all stripes and wait for them. */
if (sctx->cur_stripe >= SCRUB_STRIPES_PER_SCTX)
flush_scrub_stripes(sctx);

stripe = &sctx->stripes[sctx->cur_stripe];

/* We can queue one stripe using the remaining slot. */
scrub_reset_stripe(stripe);
ret = scrub_find_fill_first_stripe(bg, dev, physical, mirror_num,
logical, length, stripe);
/* Either >0 as no more extents or <0 for error. */
if (ret)
return ret;
sctx->cur_stripe++;
return 0;
}

/*
* Scrub one range which can only has simple mirror based profile.
* (Including all range in SINGLE/DUP/RAID1/RAID1C*, and each stripe in
Expand Down
13 changes: 4 additions & 9 deletions fs/btrfs/scrub.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,14 +18,9 @@ int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
* static functions.
*/
struct scrub_stripe;
int init_scrub_stripe(struct btrfs_fs_info *fs_info, struct scrub_stripe *stripe);
int scrub_find_fill_first_stripe(struct btrfs_block_group *bg,
struct btrfs_device *dev, u64 physical,
int mirror_num, u64 logical_start,
u32 logical_len, struct scrub_stripe *stripe);
void scrub_read_endio(struct btrfs_bio *bbio);
void scrub_write_sectors(struct scrub_ctx *sctx,
struct scrub_stripe *stripe,
unsigned long write_bitmap, bool dev_replace);
int queue_scrub_stripe(struct scrub_ctx *sctx,
struct btrfs_block_group *bg,
struct btrfs_device *dev, int mirror_num,
u64 logical, u32 length, u64 physical);

#endif

0 comments on commit 5476539

Please sign in to comment.