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FAILED: patch "[PATCH] btrfs: zoned: cache reported zone during mount" failed to apply to 5.15-stable tree

PATCH [email protected] 1 participant 1 message Jan 23, 2022

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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 <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 16beac87e95e2fb278b552397c8260637f8a63f7 Mon Sep 17 00:00:00 2001
From: Naohiro Aota <[email protected]>
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/CAHQ7scUiLtcTqZOMMY5kbWUBOhGRwKo6J6wYPT5WY+C=cD49nQ@mail.gmail.com/ open here
Fixes 5b316468983d ("btrfs: get zone information of zoned block devices")
CC [email protected]
Signed-off-by Naohiro Aota <[email protected]>
Signed-off-by David Sterba <[email protected]>
fs/btrfs/dev-replace.c +1 -1
index 82769f1c17ee..66fa61cb3f23 100644
@@ -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;
fs/btrfs/disk-io.c +2 -0
index 6408948b3e2c..67533b13e1eb 100644
@@ -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,
fs/btrfs/volumes.c +1 -1
index 53753e04af14..cafd490da072 100644
@@ -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;
fs/btrfs/zoned.c +77 -9

155 lines not on this page · raw message

fs/btrfs/zoned.h +6 -2
index e53ab7b96437..4344f4818389 100644
@@ -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)