From patchwork Thu Nov 14 08:04:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Naohiro Aota X-Patchwork-Id: 13874704 Received: from esa3.hgst.iphmx.com (esa3.hgst.iphmx.com [216.71.153.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4DA7D1F6686 for ; Thu, 14 Nov 2024 08:04:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.71.153.141 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731571488; cv=none; b=s4imYc6b6UrKTGYNddnGhzDhOPhg92f+MV0Yctxd3GHXXtJPiJYHu2mwjClUGQFlV3owCaxCdQ3adXQXSSim2GGYQUsiWmGIgABN/vVqhvHF5rfFXfphYK7tTuK1XM8ZVzze69y+8iwgmPcuDYMkRNY4TVTpCq91HoYn2MxsnNU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731571488; c=relaxed/simple; bh=/qKspSoNrijAjosztYEfSEVwQ6+wchTrIuHCfl+DERk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AcCnUX26u/BjoMccHg7BNcx4gsjEKmq8bA9k811dtYnFCliJBTphpyss9452EW/btsqbki89SSoAVwTFrgafoXW3AdjLLxfm5ckC0KwMtxXx9NSNkqE6HqV3fMMnXmSdkSP/6c3L9xbbNCL74KblM0IBFtZu5D39rPc9e1uBOl0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wdc.com; spf=pass smtp.mailfrom=wdc.com; dkim=pass (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b=XQuRrZoq; arc=none smtp.client-ip=216.71.153.141 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wdc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wdc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=wdc.com header.i=@wdc.com header.b="XQuRrZoq" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1731571487; x=1763107487; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=/qKspSoNrijAjosztYEfSEVwQ6+wchTrIuHCfl+DERk=; b=XQuRrZoq7LsjUJHHjNepMO32bPKLKDWq2F67aVTsluSS7m8yFaptBFxU gObReF24youZ1t2nj/ysv6jcPo2kEpdr2lfxQlBO53Wz2kkVyWeunKDRi kDsBh3Ophi70n5epHs9+CiLfe/loSR0O5fzXJxcZZSdr8NvWrybMTGFU9 uJGbOq7wRzOTviWHZOt65m7mXi7ZCeo5CIijkEKjTbq2hfqYky9CFNd1b 0huruaJbSjEXldgl1pvne2Bm6K8eU7HgT4falsmjhDs76YZVKQ6OFdNks DQAicPZ6BcDrIO1zvU5/Dzgo8tL/HEiXWMj72nz/n+RtO8ThYGlxGBj2o w==; X-CSE-ConnectionGUID: FEDbaTLaTs+Qys0my561tg== X-CSE-MsgGUID: 6jJcHgGSQOWcBBaB5BjHXA== X-IronPort-AV: E=Sophos;i="6.12,153,1728921600"; d="scan'208";a="31543764" Received: from h199-255-45-14.hgst.com (HELO uls-op-cesaep01.wdc.com) ([199.255.45.14]) by ob1.hgst.iphmx.com with ESMTP; 14 Nov 2024 16:04:45 +0800 IronPort-SDR: 6735a1db_HcLGGzyyHTrta7pcgAFcrRVNcuEBbX5wG75I2kZB5aR6CH6 3i2e8z5lkXcspMiIStA6MF/dr3Vx6W6dAp2K9KQ== Received: from uls-op-cesaip01.wdc.com ([10.248.3.36]) by uls-op-cesaep01.wdc.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 13 Nov 2024 23:08:12 -0800 WDCIronportException: Internal Received: from unknown (HELO naota-xeon.wdc.com) ([10.225.163.24]) by uls-op-cesaip01.wdc.com with ESMTP; 14 Nov 2024 00:04:43 -0800 From: Naohiro Aota To: linux-btrfs@vger.kernel.org Cc: Naohiro Aota Subject: [PATCH v2 3/3] btrfs: zoned: reclaim unused zone by zone resetting Date: Thu, 14 Nov 2024 17:04:29 +0900 Message-ID: X-Mailer: git-send-email 2.47.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On the zoned mode, once used and freed region is still not reusable after the freeing. The underlying zone needs to be reset before reusing. Btrfs resets a zone when it removes a block group, and then new block group is allocated on the zones to reuse the zones. But, it is sometime too late to catch up with a write side. This commit introduces a new space-info reclaim method ZONE_RESET. That will pick a block group from the unused list and reset its zone to reuse the zone_unusable space. It is faster than removing the block group and re-creating a new block group on the same zones. For the first implementation, the ZONE_RESET is only applied to a block group whose region is fully zone_unusable. Reclaiming partial zone_unusable block group could be implemented later. Signed-off-by: Naohiro Aota --- fs/btrfs/space-info.c | 28 +++++++- fs/btrfs/space-info.h | 5 ++ fs/btrfs/zoned.c | 124 +++++++++++++++++++++++++++++++++++ fs/btrfs/zoned.h | 7 ++ include/trace/events/btrfs.h | 3 +- 5 files changed, 164 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c index 7b3c514eb6f9..981da9e1b009 100644 --- a/fs/btrfs/space-info.c +++ b/fs/btrfs/space-info.c @@ -14,6 +14,7 @@ #include "fs.h" #include "accessors.h" #include "extent-tree.h" +#include "zoned.h" /* * HOW DOES SPACE RESERVATION WORK @@ -127,6 +128,14 @@ * churn a lot and we can avoid making some extent tree modifications if we * are able to delay for as long as possible. * + * RESET_ZONES + * This state works only for the zoned mode. On the zoned mode, we cannot + * reuse once allocated then freed region until we reset the zone, due to + * the sequential write zone requirement. The RESET_ZONES state resets the + * zones of an unused block group and let btrfs reuse the space. The reusing + * is faster than removing the block group and allocating another block + * group on the zones. + * * ALLOC_CHUNK * We will skip this the first time through space reservation, because of * overcommit and we don't want to have a lot of useless metadata space when @@ -832,6 +841,9 @@ static void flush_space(struct btrfs_fs_info *fs_info, */ ret = btrfs_commit_current_transaction(root); break; + case RESET_ZONES: + ret = btrfs_reset_unused_block_groups(space_info, num_bytes); + break; default: ret = -ENOSPC; break; @@ -1084,9 +1096,14 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work) enum btrfs_flush_state flush_state; int commit_cycles = 0; u64 last_tickets_id; + enum btrfs_flush_state final_state; fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work); space_info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); + if (btrfs_is_zoned(fs_info)) + final_state = RESET_ZONES; + else + final_state = COMMIT_TRANS; spin_lock(&space_info->lock); to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info, space_info); @@ -1139,7 +1156,7 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work) if (flush_state == ALLOC_CHUNK_FORCE && !commit_cycles) flush_state++; - if (flush_state > COMMIT_TRANS) { + if (flush_state > final_state) { commit_cycles++; if (commit_cycles > 2) { if (maybe_fail_all_tickets(fs_info, space_info)) { @@ -1153,7 +1170,7 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work) } } spin_unlock(&space_info->lock); - } while (flush_state <= COMMIT_TRANS); + } while (flush_state <= final_state); } /* @@ -1284,6 +1301,10 @@ static void btrfs_preempt_reclaim_metadata_space(struct work_struct *work) * This is where we reclaim all of the pinned space generated by running the * iputs * + * RESET_ZONES + * This state works only for the zoned mode. We scan the unused block + * group list and reset the zones and reuse the block group. + * * ALLOC_CHUNK_FORCE * For data we start with alloc chunk force, however we could have been full * before, and then the transaction commit could have freed new block groups, @@ -1293,6 +1314,7 @@ static const enum btrfs_flush_state data_flush_states[] = { FLUSH_DELALLOC_FULL, RUN_DELAYED_IPUTS, COMMIT_TRANS, + RESET_ZONES, ALLOC_CHUNK_FORCE, }; @@ -1384,6 +1406,7 @@ void btrfs_init_async_reclaim_work(struct btrfs_fs_info *fs_info) static const enum btrfs_flush_state priority_flush_states[] = { FLUSH_DELAYED_ITEMS_NR, FLUSH_DELAYED_ITEMS, + RESET_ZONES, ALLOC_CHUNK, }; @@ -1397,6 +1420,7 @@ static const enum btrfs_flush_state evict_flush_states[] = { FLUSH_DELALLOC_FULL, ALLOC_CHUNK, COMMIT_TRANS, + RESET_ZONES, }; static void priority_reclaim_metadata_space(struct btrfs_fs_info *fs_info, diff --git a/fs/btrfs/space-info.h b/fs/btrfs/space-info.h index 69071afc0d47..a96efdb5e681 100644 --- a/fs/btrfs/space-info.h +++ b/fs/btrfs/space-info.h @@ -79,6 +79,10 @@ enum btrfs_reserve_flush_enum { BTRFS_RESERVE_FLUSH_EMERGENCY, }; +/* + * Please be aware that the order of enum values will be the order of the reclaim + * process in btrfs_async_reclaim_metadata_space(). + */ enum btrfs_flush_state { FLUSH_DELAYED_ITEMS_NR = 1, FLUSH_DELAYED_ITEMS = 2, @@ -91,6 +95,7 @@ enum btrfs_flush_state { ALLOC_CHUNK_FORCE = 9, RUN_DELAYED_IPUTS = 10, COMMIT_TRANS = 11, + RESET_ZONES = 12, }; struct btrfs_space_info { diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index cb32966380f5..a294617dc25d 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -2648,3 +2648,127 @@ void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info) } spin_unlock(&fs_info->zone_active_bgs_lock); } + +/* + * Reset the zones of unused block groups from @space_info->bytes_zone_unusable. + * + * This one resets the zones of a block group, so we can reuse the region + * without removing the block group. On the other hand, btrfs_delete_unused_bgs() + * just removes a block group and frees up the underlying zones. So, we still + * need to allocate a new block group to reuse the zones. + * + * Resetting is faster than deleting/recreating a block group. It is similar + * to freeing the logical space on the regular mode. However, we cannot change + * the block group's profile with this operation. + * + * @space_info: the space to work on + * @num_bytes: targeting reclaim bytes + */ +int btrfs_reset_unused_block_groups(struct btrfs_space_info *space_info, u64 num_bytes) +{ + struct btrfs_fs_info *fs_info = space_info->fs_info; + const sector_t zone_size_sectors = fs_info->zone_size >> SECTOR_SHIFT; + + if (!btrfs_is_zoned(fs_info)) + return 0; + + while (num_bytes > 0) { + struct btrfs_chunk_map *map; + struct btrfs_block_group *bg = NULL; + bool found = false; + u64 reclaimed = 0; + + /* + * Here, we choose a fully zone_unusable block group. It's + * technically possible to reset a partly zone_unusable block + * group, which still has some free space left. However, + * handling that needs to cope with the allocation side, which + * makes the logic more complex. So, let's handle the easy case + * for now. + */ + spin_lock(&fs_info->unused_bgs_lock); + list_for_each_entry(bg, &fs_info->unused_bgs, bg_list) { + if ((bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK) != space_info->flags) + continue; + + /* + * Use trylock to avoid locking order violation. In + * btrfs_reclaim_bgs_work(), the lock order is + * &bg->lock -> &fs_info->unused_bgs_lock. We skips a + * block group, if we cannot take its lock. + */ + if (!spin_trylock(&bg->lock)) + continue; + if (btrfs_is_block_group_used(bg) || bg->zone_unusable < bg->length) { + spin_unlock(&bg->lock); + continue; + } + spin_unlock(&bg->lock); + found = true; + break; + } + if (!found) { + spin_unlock(&fs_info->unused_bgs_lock); + return 0; + } + + list_del_init(&bg->bg_list); + btrfs_put_block_group(bg); + spin_unlock(&fs_info->unused_bgs_lock); + + /* + * Since the block group is fully zone_unusable and we cannot + * allocate anymore from this block group, we don't need to set + * this block group read-only. + */ + + down_read(&fs_info->dev_replace.rwsem); + map = bg->physical_map; + for (int i = 0; i < map->num_stripes; i++) { + struct btrfs_io_stripe *stripe = &map->stripes[i]; + unsigned int nofs_flags; + int ret; + + nofs_flags = memalloc_nofs_save(); + ret = blkdev_zone_mgmt(stripe->dev->bdev, REQ_OP_ZONE_RESET, + stripe->physical >> SECTOR_SHIFT, + zone_size_sectors); + memalloc_nofs_restore(nofs_flags); + + if (ret) { + up_read(&fs_info->dev_replace.rwsem); + return ret; + } + } + up_read(&fs_info->dev_replace.rwsem); + + spin_lock(&space_info->lock); + spin_lock(&bg->lock); + ASSERT(!btrfs_is_block_group_used(bg)); + if (bg->ro) { + spin_unlock(&bg->lock); + spin_unlock(&space_info->lock); + continue; + } + + reclaimed = bg->alloc_offset; + bg->zone_unusable = bg->length - bg->zone_capacity; + bg->alloc_offset = 0; + /* + * This holds because we currently reset fully used then freed + * block group. + */ + ASSERT(reclaimed == bg->zone_capacity); + bg->free_space_ctl->free_space += reclaimed; + space_info->bytes_zone_unusable -= reclaimed; + spin_unlock(&bg->lock); + btrfs_return_free_space(space_info, reclaimed); + spin_unlock(&space_info->lock); + + if (num_bytes <= reclaimed) + break; + num_bytes -= reclaimed; + } + + return 0; +} diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h index 7612e6572605..9672bf4c3335 100644 --- a/fs/btrfs/zoned.h +++ b/fs/btrfs/zoned.h @@ -96,6 +96,7 @@ int btrfs_zone_finish_one_bg(struct btrfs_fs_info *fs_info); int btrfs_zoned_activate_one_bg(struct btrfs_fs_info *fs_info, struct btrfs_space_info *space_info, bool do_finish); void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info); +int btrfs_reset_unused_block_groups(struct btrfs_space_info *space_info, u64 num_bytes); #else /* CONFIG_BLK_DEV_ZONED */ static inline int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info) @@ -265,6 +266,12 @@ static inline int btrfs_zoned_activate_one_bg(struct btrfs_fs_info *fs_info, static inline void btrfs_check_active_zone_reservation(struct btrfs_fs_info *fs_info) { } +static inline int btrfs_reset_unused_block_groups(struct btrfs_space_info *space_info, + u64 num_bytes) +{ + return 0; +} + #endif static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos) diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h index 4df93ca9b7a8..549ab3b41961 100644 --- a/include/trace/events/btrfs.h +++ b/include/trace/events/btrfs.h @@ -100,7 +100,8 @@ struct find_free_extent_ctl; EM( ALLOC_CHUNK, "ALLOC_CHUNK") \ EM( ALLOC_CHUNK_FORCE, "ALLOC_CHUNK_FORCE") \ EM( RUN_DELAYED_IPUTS, "RUN_DELAYED_IPUTS") \ - EMe(COMMIT_TRANS, "COMMIT_TRANS") + EM( COMMIT_TRANS, "COMMIT_TRANS") \ + EMe(RESET_ZONES, "RESET_ZONES") /* * First define the enums in the above macros to be exported to userspace via