On Fri, Oct 30, 2020 at 10:51:19PM +0900, Naohiro Aota wrote:
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1416,6 +1416,14 @@ static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
> return false;
> }
>
> +static inline u64 dev_extent_search_start_zoned(struct btrfs_device *device,
> + u64 start)
> +{
> + start = max_t(u64, start,
> + max_t(u64, device->zone_info->zone_size, SZ_1M));
Can you rewrite that as ifs?
> + return btrfs_zone_align(device, start);
> +}
> +
> static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
> {
> switch (device->fs_devices->chunk_alloc_policy) {
> @@ -1426,11 +1434,57 @@ static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
> * make sure to start at an offset of at least 1MB.
> */
> return max_t(u64, start, SZ_1M);
> + case BTRFS_CHUNK_ALLOC_ZONED:
> + return dev_extent_search_start_zoned(device, start);
> default:
> BUG();
> }
> }
>
> +static bool dev_extent_hole_check_zoned(struct btrfs_device *device,
> + u64 *hole_start, u64 *hole_size,
> + u64 num_bytes)
> +{
> + u64 zone_size = device->zone_info->zone_size;
> + u64 pos;
> + int ret;
> + int changed = 0;
> +
> + ASSERT(IS_ALIGNED(*hole_start, zone_size));
> +
> + while (*hole_size > 0) {
> + pos = btrfs_find_allocatable_zones(device, *hole_start,
> + *hole_start + *hole_size,
> + num_bytes);
> + if (pos != *hole_start) {
> + *hole_size = *hole_start + *hole_size - pos;
> + *hole_start = pos;
> + changed = 1;
> + if (*hole_size < num_bytes)
> + break;
> + }
> +
> + ret = btrfs_ensure_empty_zones(device, pos, num_bytes);
> +
> + /* range is ensured to be empty */
/* Range ... */
> + if (!ret)
> + return changed;
> +
> + /* given hole range was invalid (outside of device) */
/* Given ... */
> + if (ret == -ERANGE) {
> + *hole_start += *hole_size;
> + *hole_size = 0;
> + return 1;
> + }
> +
> + *hole_start += zone_size;
> + *hole_size -= zone_size;
> + changed = 1;
> + }
> +
> + return changed;
> +}
> +
> /**
> * dev_extent_hole_check - check if specified hole is suitable for allocation
> * @device: the device which we have the hole
> @@ -1463,6 +1517,10 @@ static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start,
> case BTRFS_CHUNK_ALLOC_REGULAR:
> /* No extra check */
> break;
> + case BTRFS_CHUNK_ALLOC_ZONED:
> + changed |= dev_extent_hole_check_zoned(device, hole_start,
> + hole_size, num_bytes);
> + break;
> default:
> BUG();
> }
> @@ -1517,6 +1575,9 @@ static int find_free_dev_extent_start(struct btrfs_device *device,
>
> search_start = dev_extent_search_start(device, search_start);
>
> + WARN_ON(device->zone_info &&
> + !IS_ALIGNED(num_bytes, device->zone_info->zone_size));
> +
> path = btrfs_alloc_path();
> if (!path)
> return -ENOMEM;
> @@ -4907,6 +4968,37 @@ static void init_alloc_chunk_ctl_policy_regular(
> ctl->dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
> }
>
> +static void
> +init_alloc_chunk_ctl_policy_zoned(struct btrfs_fs_devices *fs_devices,
> + struct alloc_chunk_ctl *ctl)
static void init_alloc_chunk_ctl_policy_zoned(
Ie. type and name on one line
> +{
> + u64 zone_size = fs_devices->fs_info->zone_size;
> + u64 limit;
> + int min_num_stripes = ctl->devs_min * ctl->dev_stripes;
> + int min_data_stripes = (min_num_stripes - ctl->nparity) / ctl->ncopies;
> + u64 min_chunk_size = min_data_stripes * zone_size;
> + u64 type = ctl->type;
> +
> + ctl->max_stripe_size = zone_size;
> + if (type & BTRFS_BLOCK_GROUP_DATA) {
> + ctl->max_chunk_size = round_down(BTRFS_MAX_DATA_CHUNK_SIZE,
> + zone_size);
> + } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
> + ctl->max_chunk_size = ctl->max_stripe_size;
> + } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
> + ctl->max_chunk_size = 2 * ctl->max_stripe_size;
> + ctl->devs_max = min_t(int, ctl->devs_max,
> + BTRFS_MAX_DEVS_SYS_CHUNK);
> + }
> +
> + /* We don't want a chunk larger than 10% of writable space */
> + limit = max(round_down(div_factor(fs_devices->total_rw_bytes, 1),
> + zone_size),
> + min_chunk_size);
> + ctl->max_chunk_size = min(limit, ctl->max_chunk_size);
> + ctl->dev_extent_min = zone_size * ctl->dev_stripes;
> +}
> +
> static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
> struct alloc_chunk_ctl *ctl)
> {
> @@ -4927,6 +5019,9 @@ static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
> case BTRFS_CHUNK_ALLOC_REGULAR:
> init_alloc_chunk_ctl_policy_regular(fs_devices, ctl);
> break;
> + case BTRFS_CHUNK_ALLOC_ZONED:
> + init_alloc_chunk_ctl_policy_zoned(fs_devices, ctl);
> + break;
> default:
> BUG();
> }
> @@ -5053,6 +5148,40 @@ static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl,
> return 0;
> }
>
> +static int decide_stripe_size_zoned(struct alloc_chunk_ctl *ctl,
> + struct btrfs_device_info *devices_info)
> +{
> + u64 zone_size = devices_info[0].dev->zone_info->zone_size;
> + /* number of stripes that count for block group size */
/* Number ... */
> + int data_stripes;
> +
> + /*
> + * It should hold because:
> + * dev_extent_min == dev_extent_want == zone_size * dev_stripes
> + */
> + ASSERT(devices_info[ctl->ndevs - 1].max_avail == ctl->dev_extent_min);
> +
> + ctl->stripe_size = zone_size;
> + ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
> + data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
> +
> + /*
> + * stripe_size is fixed in ZONED. Reduce ndevs instead.
/* One line comment if it fits to 80 cols */
> + */
> + if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) {
> + ctl->ndevs = div_u64(div_u64(ctl->max_chunk_size * ctl->ncopies,
> + ctl->stripe_size) + ctl->nparity,
> + ctl->dev_stripes);
> + ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
> + data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
> + ASSERT(ctl->stripe_size * data_stripes <= ctl->max_chunk_size);
> + }
> +
> + ctl->chunk_size = ctl->stripe_size * data_stripes;
> +
> + return 0;
> +}
> +
> static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
> struct alloc_chunk_ctl *ctl,
> struct btrfs_device_info *devices_info)
> --- a/fs/btrfs/zoned.c
> +++ b/fs/btrfs/zoned.c
> @@ -607,3 +610,126 @@ int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror)
> sb_zone << zone_sectors_shift, zone_sectors * 2,
> GFP_NOFS);
> }
> +
> +/*
> + * btrfs_check_allocatable_zones - find allocatable zones within give region
> + * @device: the device to allocate a region
> + * @hole_start: the position of the hole to allocate the region
> + * @num_bytes: the size of wanted region
> + * @hole_size: the size of hole
> + *
> + * Allocatable region should not contain any superblock locations.
> + */
> +u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
> + u64 hole_end, u64 num_bytes)
> +{
> + struct btrfs_zoned_device_info *zinfo = device->zone_info;
> + u8 shift = zinfo->zone_size_shift;
> + u64 nzones = num_bytes >> shift;
> + u64 pos = hole_start;
> + u64 begin, end;
> + u64 sb_pos;
> + bool have_sb;
> + int i;
> +
> + ASSERT(IS_ALIGNED(hole_start, zinfo->zone_size));
> + ASSERT(IS_ALIGNED(num_bytes, zinfo->zone_size));
> +
> + while (pos < hole_end) {
> + begin = pos >> shift;
> + end = begin + nzones;
> +
> + if (end > zinfo->nr_zones)
> + return hole_end;
> +
> + /* check if zones in the region are all empty */
/* Check ... */
> + if (btrfs_dev_is_sequential(device, pos) &&
> + find_next_zero_bit(zinfo->empty_zones, end, begin) != end) {
> + pos += zinfo->zone_size;
> + continue;
> + }
> +
> + have_sb = false;
> + for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
> + sb_pos = sb_zone_number(zinfo->zone_size, i);
> + if (!(end < sb_pos || sb_pos + 1 < begin)) {
> + have_sb = true;
> + pos = (sb_pos + 2) << shift;
> + break;
> + }
> + }
> + if (!have_sb)
> + break;
> + }
> +
> + return pos;
> +}
> +
> +int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
> + u64 length, u64 *bytes)
> +{
> + int ret;
> +
> + *bytes = 0;
> + ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_RESET,
> + physical >> SECTOR_SHIFT, length >> SECTOR_SHIFT,
> + GFP_NOFS);
> + if (ret)
> + return ret;
> +
> + *bytes = length;
> + while (length) {
> + btrfs_dev_set_zone_empty(device, physical);
> + physical += device->zone_info->zone_size;
> + length -= device->zone_info->zone_size;
> + }
> +
> + return 0;
> +}
> +
> +int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size)
> +{
> + struct btrfs_zoned_device_info *zinfo = device->zone_info;
> + u8 shift = zinfo->zone_size_shift;
> + unsigned long begin = start >> shift;
> + unsigned long end = (start + size) >> shift;
> + u64 pos;
> + int ret;
> +
> + ASSERT(IS_ALIGNED(start, zinfo->zone_size));
> + ASSERT(IS_ALIGNED(size, zinfo->zone_size));
> +
> + if (end > zinfo->nr_zones)
> + return -ERANGE;
> +
> + /* all the zones are conventional */
/* All ... */
> + if (find_next_bit(zinfo->seq_zones, begin, end) == end)
> + return 0;
> +
> + /* all the zones are sequential and empty */
/* All ... */
> + if (find_next_zero_bit(zinfo->seq_zones, begin, end) == end &&
> + find_next_zero_bit(zinfo->empty_zones, begin, end) == end)
> + return 0;
> +
> + for (pos = start; pos < start + size; pos += zinfo->zone_size) {
> + u64 reset_bytes;
> +
> + if (!btrfs_dev_is_sequential(device, pos) ||
> + btrfs_dev_is_empty_zone(device, pos))
> + continue;
> +
> + /* free regions should be empty */
/* Free ... */
> + btrfs_warn_in_rcu(
> + device->fs_info,
> + "resetting device %s zone %llu for allocation",
"zoned: resetting device %s (devid %llu) zone %llu for allocation
> + rcu_str_deref(device->name), pos >> shift);
> + WARN_ON_ONCE(1);
> +
> + ret = btrfs_reset_device_zone(device, pos, zinfo->zone_size,
> + &reset_bytes);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h
> index 447c4e5ffcbb..24dd0c9561f9 100644
> --- a/fs/btrfs/zoned.h
> +++ b/fs/btrfs/zoned.h
> @@ -34,6 +34,11 @@ int btrfs_sb_log_location(struct btrfs_device *device, int mirror, int rw,
> u64 *bytenr_ret);
> void btrfs_advance_sb_log(struct btrfs_device *device, int mirror);
> int btrfs_reset_sb_log_zones(struct block_device *bdev, int mirror);
> +u64 btrfs_find_allocatable_zones(struct btrfs_device *device, u64 hole_start,
> + u64 hole_end, u64 num_bytes);
> +int btrfs_reset_device_zone(struct btrfs_device *device, u64 physical,
> + u64 length, u64 *bytes);
> +int btrfs_ensure_empty_zones(struct btrfs_device *device, u64 start, u64 size);
> #else /* CONFIG_BLK_DEV_ZONED */
> static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos,
> struct blk_zone *zone)
> @@ -77,6 +82,23 @@ static inline int btrfs_reset_sb_log_zones(struct block_device *bdev,
> {
> return 0;
> }
newline
> +static inline u64 btrfs_find_allocatable_zones(struct btrfs_device *device,
> + u64 hole_start, u64 hole_end,
> + u64 num_bytes)
> +{
> + return hole_start;
> +}
newline
> +static inline int btrfs_reset_device_zone(struct btrfs_device *device,
> + u64 physical, u64 length, u64 *bytes)
> +{
> + *bytes = 0;
> + return 0;
> +}
newline
> +static inline int btrfs_ensure_empty_zones(struct btrfs_device *device,
> + u64 start, u64 size)
> +{
> + return 0;
> +}
newline
> #endif
>
> static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)
> @@ -155,4 +177,12 @@ static inline bool btrfs_check_super_location(struct btrfs_device *device,
> !btrfs_dev_is_sequential(device, pos);
> }
>
> +static inline u64 btrfs_zone_align(struct btrfs_device *device, u64 pos)
I can't tell from the name what it does, something like
btrfs_align_offset_to_zone would be more clear.
> +{
> + if (!device->zone_info)
> + return pos;
> +
> + return ALIGN(pos, device->zone_info->zone_size);
> +}
> +
> #endif
> --
> 2.27.0
