btrfs-progs: fix duplicate missing device

Commit Message

Anand Jain July 3, 2023, 7:53 a.m. UTC

btrfs_read_sys_array() adds a device with only devid, but without the
device UUID. As a result, any subsequent
btrfs_find_device(..devid, uuid) calls will still fail, resulting in the
addition of another struct btrfs_device to the list, as shown below.

open_ctree_fd()
::
 btrfs_setup_chunk_tree_and_device_map()
  btrfs_read_sys_array()
   read_one_chunk()
    btrfs_find_device()
    fill_missing_device() <--- dev_uuid wasn't updated
    list_add()
  btrfs_read_chunk_tree
    read_one_dev()
       btrfs_find_device(..,devid, dev_uuid,..); <-- fails
       list_add
       fill_device_from_item(leaf, dev_item, device);

This ends up having two btrfs_device for the same missing devid.

Before:

There are two device with devid 1.

$ ./btrfstune -m --noscan  /tdev/disk4.raw
warning, device 1 is missing
[fsid: 95bbc163-671a-4a0a-bd34-03a65e4b338c]
	size:			120
	metadata_uuid:		95bbc163-671a-4a0a-bd34-03a65e4b338c
	fs_devs_addr:		0xdb64e0
	total_rw_bytes:		1048576000
	[[UUID: 703a4cac-bca0-47e4-98f6-55e530800172]]
		sb_flags: 0x0
		sb_incompact_flags: 0x0
		dev_addr:	0xdb69a0
		device:		(null)
		devid:		1
		generation:	0
		total_bytes:	524288000
		bytes_used:	127926272
		type:		0
		io_align:	4096
		io_width:	4096
		sector_size:	4096
	[[UUID: 00000000-0000-0000-0000-000000000000]]
		sb_flags: 0x0
		sb_incompact_flags: 0x0
		dev_addr:	0xdb3060
		device:		(null)
		devid:		1
		generation:	0
		total_bytes:	0
		bytes_used:	0
		type:		0
		io_align:	0
		io_width:	0
		sector_size:	0
	[[UUID: 1db7564f-e53b-46ff-8a33-a8b2d00d86d1]]
		sb_flags: 0x1000000001
		sb_incompact_flags: 0x141
		dev_addr:	0xdb6e90
		device:		/tdev/disk4.raw
		devid:		2
		generation:	6
		total_bytes:	524288000
		bytes_used:	127926272
		type:		0
		io_align:	4096
		io_width:	4096
		sector_size:	4096

Fix this issue by adding the UUID to the missing device created in
fill_missing_device().

After:

$ ./btrfstune -m --noscan  /tdev/disk4.raw
warning, device 1 is missing
[fsid: 95bbc163-671a-4a0a-bd34-03a65e4b338c]
        size:                   120
        metadata_uuid:          95bbc163-671a-4a0a-bd34-03a65e4b338c
        fs_devs_addr:           0x161f380
        total_rw_bytes:         1048576000
        [[UUID: 703a4cac-bca0-47e4-98f6-55e530800172]]
                sb_flags: 0x0
                sb_incompact_flags: 0x0
                dev_addr:       0x161c060
                device:         (null)
                devid:          1
                generation:     0
                total_bytes:    524288000
                bytes_used:     127926272
                type:           0
                io_align:       4096
                io_width:       4096
                sector_size:    4096
        [[UUID: 1db7564f-e53b-46ff-8a33-a8b2d00d86d1]]
                sb_flags: 0x1000000001
                sb_incompact_flags: 0x141
                dev_addr:       0x161fe90
                device:         /tdev/disk4.raw
                devid:          2
                generation:     6
                total_bytes:    524288000
                bytes_used:     127926272
                type:           0
                io_align:       4096
                io_width:       4096
                sector_size:    4096

Signed-off-by: Anand Jain <[e-mail]>
---
 kernel-shared/volumes.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Anand Jain July 7, 2023, 5:58 a.m. UTC | #1

Please ignore this patch, as it has been added to an upcoming
patch set that fixes the incomplete fsid change.

Thanks, Anand

Patch

diff --git a/kernel-shared/volumes.c b/kernel-shared/volumes.c
index 88d13e047379..4347acfe95e1 100644
--- a/kernel-shared/volumes.c
+++ b/kernel-shared/volumes.c
@@ -2079,12 +2079,13 @@  int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset)
 	return readonly;
 }
 
-static struct btrfs_device *fill_missing_device(u64 devid)
+static struct btrfs_device *fill_missing_device(u64 devid, u8 *uuid)
 {
 	struct btrfs_device *device;
 
 	device = kzalloc(sizeof(*device), GFP_NOFS);
 	device->devid = devid;
+	memcpy(device->uuid, uuid, BTRFS_UUID_SIZE);
 	device->fd = -1;
 	return device;
 }
@@ -2152,7 +2153,7 @@  static int read_one_chunk(struct btrfs_fs_info *fs_info, struct btrfs_key *key,
 		map->stripes[i].dev = btrfs_find_device(fs_info, devid, uuid,
 							NULL);
 		if (!map->stripes[i].dev) {
-			map->stripes[i].dev = fill_missing_device(devid);
+			map->stripes[i].dev = fill_missing_device(devid, uuid);
 			printf("warning, device %llu is missing\n",
 			       (unsigned long long)devid);
 			list_add(&map->stripes[i].dev->dev_list,