From c2ae7b772ef4e86c5ddf3fd47bf59045ae96a414 Mon Sep 17 00:00:00 2001 From: Naohiro Aota Date: Sat, 9 Jul 2022 08:18:39 +0900 Subject: [PATCH] btrfs: zoned: revive max_zone_append_bytes This patch is basically a revert of commit 5a80d1c6a270 ("btrfs: zoned: remove max_zone_append_size logic"), but without unnecessary ASSERT and check. The max_zone_append_size will be used as a hint to estimate the number of extents to cover delalloc/writeback region in the later commits. The size of a ZONE APPEND bio is also limited by queue_max_segments(), so this commit considers it to calculate max_zone_append_size. Technically, a bio can be larger than queue_max_segments() * PAGE_SIZE if the pages are contiguous. But, it is safe to consider "queue_max_segments() * PAGE_SIZE" as an upper limit of an extent size to calculate the number of extents needed to write data. Reviewed-by: Johannes Thumshirn Signed-off-by: Naohiro Aota Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 2 ++ fs/btrfs/zoned.c | 17 +++++++++++++++++ fs/btrfs/zoned.h | 1 + 3 files changed, 20 insertions(+) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 64c65d0f7d06..b2a161227ac5 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1070,6 +1070,8 @@ struct btrfs_fs_info { */ u64 zone_size; + /* Max size to emit ZONE_APPEND write command */ + u64 max_zone_append_size; struct mutex zoned_meta_io_lock; spinlock_t treelog_bg_lock; u64 treelog_bg; diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index 79a2d48a5251..bdc533fa80ae 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -415,6 +415,16 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache) nr_sectors = bdev_nr_sectors(bdev); zone_info->zone_size_shift = ilog2(zone_info->zone_size); zone_info->nr_zones = nr_sectors >> ilog2(zone_sectors); + /* + * We limit max_zone_append_size also by max_segments * + * PAGE_SIZE. Technically, we can have multiple pages per segment. But, + * since btrfs adds the pages one by one to a bio, and btrfs cannot + * increase the metadata reservation even if it increases the number of + * extents, it is safe to stick with the limit. + */ + zone_info->max_zone_append_size = + min_t(u64, (u64)bdev_max_zone_append_sectors(bdev) << SECTOR_SHIFT, + (u64)bdev_max_segments(bdev) << PAGE_SHIFT); if (!IS_ALIGNED(nr_sectors, zone_sectors)) zone_info->nr_zones++; @@ -640,6 +650,7 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info) u64 zoned_devices = 0; u64 nr_devices = 0; u64 zone_size = 0; + u64 max_zone_append_size = 0; const bool incompat_zoned = btrfs_fs_incompat(fs_info, ZONED); int ret = 0; @@ -674,6 +685,11 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info) ret = -EINVAL; goto out; } + if (!max_zone_append_size || + (zone_info->max_zone_append_size && + zone_info->max_zone_append_size < max_zone_append_size)) + max_zone_append_size = + zone_info->max_zone_append_size; } nr_devices++; } @@ -723,6 +739,7 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info) } fs_info->zone_size = zone_size; + fs_info->max_zone_append_size = max_zone_append_size; fs_info->fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_ZONED; /* diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h index 6b2eec99162b..9caeab07fd38 100644 --- a/fs/btrfs/zoned.h +++ b/fs/btrfs/zoned.h @@ -19,6 +19,7 @@ struct btrfs_zoned_device_info { */ u64 zone_size; u8 zone_size_shift; + u64 max_zone_append_size; u32 nr_zones; unsigned int max_active_zones; atomic_t active_zones_left;