The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 16beac87e95e2fb278b552397c8260637f8a63f7 Mon Sep 17 00:00:00 2001 From: Naohiro Aota naohiro.aota@wdc.com Date: Thu, 11 Nov 2021 14:14:38 +0900 Subject: [PATCH] btrfs: zoned: cache reported zone during mount
When mounting a device, we are reporting the zones twice: once for checking the zone attributes in btrfs_get_dev_zone_info and once for loading block groups' zone info in btrfs_load_block_group_zone_info(). With a lot of block groups, that leads to a lot of REPORT ZONE commands and slows down the mount process.
This patch introduces a zone info cache in struct btrfs_zoned_device_info. The cache is populated while in btrfs_get_dev_zone_info() and used for btrfs_load_block_group_zone_info() to reduce the number of REPORT ZONE commands. The zone cache is then released after loading the block groups, as it will not be much effective during the run time.
Benchmark: Mount an HDD with 57,007 block groups Before patch: 171.368 seconds After patch: 64.064 seconds
While it still takes a minute due to the slowness of loading all the block groups, the patch reduces the mount time by 1/3.
Link: https://lore.kernel.org/linux-btrfs/CAHQ7scUiLtcTqZOMMY5kbWUBOhGRwKo6J6wYPT5... Fixes: 5b316468983d ("btrfs: get zone information of zoned block devices") CC: stable@vger.kernel.org Signed-off-by: Naohiro Aota naohiro.aota@wdc.com Signed-off-by: David Sterba dsterba@suse.com
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 82769f1c17ee..66fa61cb3f23 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -322,7 +322,7 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info, set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE); device->fs_devices = fs_info->fs_devices;
- ret = btrfs_get_dev_zone_info(device); + ret = btrfs_get_dev_zone_info(device, false); if (ret) goto error;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 6408948b3e2c..67533b13e1eb 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3570,6 +3570,8 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device goto fail_sysfs; }
+ btrfs_free_zone_cache(fs_info); + if (!sb_rdonly(sb) && fs_info->fs_devices->missing_devices && !btrfs_check_rw_degradable(fs_info, NULL)) { btrfs_warn(fs_info, diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 53753e04af14..cafd490da072 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2669,7 +2669,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path device->fs_info = fs_info; device->bdev = bdev;
- ret = btrfs_get_dev_zone_info(device); + ret = btrfs_get_dev_zone_info(device, false); if (ret) goto error_free_device;
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index 678a29469511..b06059a5db2a 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -5,6 +5,7 @@ #include <linux/blkdev.h> #include <linux/sched/mm.h> #include <linux/atomic.h> +#include <linux/vmalloc.h> #include "ctree.h" #include "volumes.h" #include "zoned.h" @@ -213,6 +214,8 @@ static int emulate_report_zones(struct btrfs_device *device, u64 pos, static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos, struct blk_zone *zones, unsigned int *nr_zones) { + struct btrfs_zoned_device_info *zinfo = device->zone_info; + u32 zno; int ret;
if (!*nr_zones) @@ -224,6 +227,34 @@ static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos, return 0; }
+ /* Check cache */ + if (zinfo->zone_cache) { + unsigned int i; + + ASSERT(IS_ALIGNED(pos, zinfo->zone_size)); + zno = pos >> zinfo->zone_size_shift; + /* + * We cannot report zones beyond the zone end. So, it is OK to + * cap *nr_zones to at the end. + */ + *nr_zones = min_t(u32, *nr_zones, zinfo->nr_zones - zno); + + for (i = 0; i < *nr_zones; i++) { + struct blk_zone *zone_info; + + zone_info = &zinfo->zone_cache[zno + i]; + if (!zone_info->len) + break; + } + + if (i == *nr_zones) { + /* Cache hit on all the zones */ + memcpy(zones, zinfo->zone_cache + zno, + sizeof(*zinfo->zone_cache) * *nr_zones); + return 0; + } + } + ret = blkdev_report_zones(device->bdev, pos >> SECTOR_SHIFT, *nr_zones, copy_zone_info_cb, zones); if (ret < 0) { @@ -237,6 +268,11 @@ static int btrfs_get_dev_zones(struct btrfs_device *device, u64 pos, if (!ret) return -EIO;
+ /* Populate cache */ + if (zinfo->zone_cache) + memcpy(zinfo->zone_cache + zno, zones, + sizeof(*zinfo->zone_cache) * *nr_zones); + return 0; }
@@ -300,7 +336,7 @@ int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info) if (!device->bdev) continue;
- ret = btrfs_get_dev_zone_info(device); + ret = btrfs_get_dev_zone_info(device, true); if (ret) break; } @@ -309,7 +345,7 @@ int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info) return ret; }
-int btrfs_get_dev_zone_info(struct btrfs_device *device) +int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache) { struct btrfs_fs_info *fs_info = device->fs_info; struct btrfs_zoned_device_info *zone_info = NULL; @@ -339,6 +375,8 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device) if (!zone_info) return -ENOMEM;
+ device->zone_info = zone_info; + if (!bdev_is_zoned(bdev)) { if (!fs_info->zone_size) { ret = calculate_emulated_zone_size(fs_info); @@ -407,6 +445,23 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device) goto out; }
+ /* + * Enable zone cache only for a zoned device. On a non-zoned device, we + * fill the zone info with emulated CONVENTIONAL zones, so no need to + * use the cache. + */ + if (populate_cache && bdev_is_zoned(device->bdev)) { + zone_info->zone_cache = vzalloc(sizeof(struct blk_zone) * + zone_info->nr_zones); + if (!zone_info->zone_cache) { + btrfs_err_in_rcu(device->fs_info, + "zoned: failed to allocate zone cache for %s", + rcu_str_deref(device->name)); + ret = -ENOMEM; + goto out; + } + } + /* Get zones type */ nactive = 0; while (sector < nr_sectors) { @@ -505,8 +560,6 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
kfree(zones);
- device->zone_info = zone_info; - switch (bdev_zoned_model(bdev)) { case BLK_ZONED_HM: model = "host-managed zoned"; @@ -539,11 +592,7 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device) out: kfree(zones); out_free_zone_info: - bitmap_free(zone_info->active_zones); - bitmap_free(zone_info->empty_zones); - bitmap_free(zone_info->seq_zones); - kfree(zone_info); - device->zone_info = NULL; + btrfs_destroy_dev_zone_info(device);
return ret; } @@ -558,6 +607,7 @@ void btrfs_destroy_dev_zone_info(struct btrfs_device *device) bitmap_free(zone_info->active_zones); bitmap_free(zone_info->seq_zones); bitmap_free(zone_info->empty_zones); + vfree(zone_info->zone_cache); kfree(zone_info); device->zone_info = NULL; } @@ -1975,3 +2025,21 @@ void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg) fs_info->data_reloc_bg = 0; spin_unlock(&fs_info->relocation_bg_lock); } + +void btrfs_free_zone_cache(struct btrfs_fs_info *fs_info) +{ + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_device *device; + + if (!btrfs_is_zoned(fs_info)) + return; + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry(device, &fs_devices->devices, dev_list) { + if (device->zone_info) { + vfree(device->zone_info->zone_cache); + device->zone_info->zone_cache = NULL; + } + } + mutex_unlock(&fs_devices->device_list_mutex); +} diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h index e53ab7b96437..4344f4818389 100644 --- a/fs/btrfs/zoned.h +++ b/fs/btrfs/zoned.h @@ -28,6 +28,7 @@ struct btrfs_zoned_device_info { unsigned long *seq_zones; unsigned long *empty_zones; unsigned long *active_zones; + struct blk_zone *zone_cache; struct blk_zone sb_zones[2 * BTRFS_SUPER_MIRROR_MAX]; };
@@ -35,7 +36,7 @@ struct btrfs_zoned_device_info { int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos, struct blk_zone *zone); int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_info); -int btrfs_get_dev_zone_info(struct btrfs_device *device); +int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache); void btrfs_destroy_dev_zone_info(struct btrfs_device *device); int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info); int btrfs_check_mountopts_zoned(struct btrfs_fs_info *info); @@ -76,6 +77,7 @@ bool btrfs_can_activate_zone(struct btrfs_fs_devices *fs_devices, void btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info, u64 logical, u64 length); void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg); +void btrfs_free_zone_cache(struct btrfs_fs_info *fs_info); #else /* CONFIG_BLK_DEV_ZONED */ static inline int btrfs_get_dev_zone(struct btrfs_device *device, u64 pos, struct blk_zone *zone) @@ -88,7 +90,8 @@ static inline int btrfs_get_dev_zone_info_all_devices(struct btrfs_fs_info *fs_i return 0; }
-static inline int btrfs_get_dev_zone_info(struct btrfs_device *device) +static inline int btrfs_get_dev_zone_info(struct btrfs_device *device, + bool populate_cache) { return 0; } @@ -232,6 +235,7 @@ static inline void btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info,
static inline void btrfs_clear_data_reloc_bg(struct btrfs_block_group *bg) { }
+static inline void btrfs_free_zone_cache(struct btrfs_fs_info *fs_info) { } #endif
static inline bool btrfs_dev_is_sequential(struct btrfs_device *device, u64 pos)