* [PATCH] btrfs-progs: mkfs: use path_canonicalize for input device
@ 2025-05-15 14:16 Anand Jain
2025-05-16 1:43 ` Qu Wenruo
0 siblings, 1 reply; 3+ messages in thread
From: Anand Jain @ 2025-05-15 14:16 UTC (permalink / raw)
To: linux-btrfs
Canonicalize the input device's path before using it.
So that we show the device path that matches with the /proc/fs/
Before:
$ mkfs.btrfs -fq /dev/vg_fstests/lv1 /dev/sdb > /dev/null
$ blkid --uuid c3bf2107-292d-4c7f-a288-0fa922ebd71a
/dev/mapper/vg_fstests-lv1
$ mount --verbose /dev/vg_fstests/lv1 /mnt/scratch
mount: /dev/mapper/vg_fstests-lv1 mounted on /mnt/scratch.
$ cat /proc/self/mounts | grep scratch
/dev/vg_fstests/lv1 /mnt/scratch btrfs rw,relatime,space_cache=v2,subvolid=5,subvol=/ 0 0
After:
$ mkfs.btrfs -fq /dev/vg_fstests/lv1 /dev/sdb > /dev/null
$ blkid --uuid c774b4a6-3ad2-4b15-834a-894dfc898aa9
/dev/mapper/vg_fstests-lv1
$ mount --verbose /dev/vg_fstests/lv1 /mnt/scratch
mount: /dev/mapper/vg_fstests-lv1 mounted on /mnt/scratch.
$ cat /proc/self/mounts | grep scratch
/dev/mapper/vg_fstests-lv1 /mnt/scratch btrfs rw,relatime,space_cache=v2,subvolid=5,subvol=/ 0 0
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Link: https://lore.kernel.org/linux-btrfs/5f401c48-29f5-403e-8c39-50188028ad00@oracle.com/
---
mkfs/main.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/mkfs/main.c b/mkfs/main.c
index 4c2ce98c784c..e6466d88313a 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -1537,7 +1537,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
}
for (i = 0; i < device_count; i++) {
- file = argv[optind++];
+ file = path_canonicalize(argv[optind++]);
if (source_dir && path_exists(file) == 0)
ret = 0;
@@ -1553,7 +1553,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
optind = saved_optind;
device_count = argc - optind;
- file = argv[optind++];
+ file = path_canonicalize(argv[optind++]);
ssd = device_get_rotational(file);
if (opt_zoned) {
if (!zone_size(file)) {
@@ -1752,7 +1752,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
for (i = saved_optind; i < saved_optind + device_count; i++) {
char *path;
- path = argv[i];
+ path = path_canonicalize(argv[i]);
ret = test_minimum_size(path, min_dev_size);
if (ret < 0) {
error("failed to check size for %s: %m", path);
@@ -1816,7 +1816,8 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
opt_oflags = O_RDWR;
for (i = 0; i < device_count; i++) {
if (opt_zoned &&
- zoned_model(argv[optind + i - 1]) == ZONED_HOST_MANAGED) {
+ zoned_model(path_canonicalize(argv[optind + i - 1])) ==
+ ZONED_HOST_MANAGED) {
opt_oflags |= O_DIRECT;
break;
}
@@ -1824,7 +1825,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
/* Start threads */
for (i = 0; i < device_count; i++) {
- prepare_ctx[i].file = argv[optind + i - 1];
+ prepare_ctx[i].file = path_canonicalize(argv[optind + i - 1]);
prepare_ctx[i].byte_count = byte_count;
prepare_ctx[i].dev_byte_count = byte_count;
ret = pthread_create(&t_prepare[i], NULL, prepare_one_device,
@@ -2198,7 +2199,7 @@ out:
optind = saved_optind;
device_count = argc - optind;
while (device_count-- > 0) {
- file = argv[optind++];
+ file = path_canonicalize(argv[optind++]);
if (path_is_block_device(file) == 1)
btrfs_register_one_device(file);
}
--
2.49.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] btrfs-progs: mkfs: use path_canonicalize for input device
2025-05-15 14:16 [PATCH] btrfs-progs: mkfs: use path_canonicalize for input device Anand Jain
@ 2025-05-16 1:43 ` Qu Wenruo
2025-05-20 10:53 ` Anand Jain
0 siblings, 1 reply; 3+ messages in thread
From: Qu Wenruo @ 2025-05-16 1:43 UTC (permalink / raw)
To: Anand Jain, linux-btrfs
在 2025/5/15 23:46, Anand Jain 写道:
> Canonicalize the input device's path before using it.
> So that we show the device path that matches with the /proc/fs/
>
> Before:
> $ mkfs.btrfs -fq /dev/vg_fstests/lv1 /dev/sdb > /dev/null
>
> $ blkid --uuid c3bf2107-292d-4c7f-a288-0fa922ebd71a
> /dev/mapper/vg_fstests-lv1
>
> $ mount --verbose /dev/vg_fstests/lv1 /mnt/scratch
> mount: /dev/mapper/vg_fstests-lv1 mounted on /mnt/scratch.
>
> $ cat /proc/self/mounts | grep scratch
> /dev/vg_fstests/lv1 /mnt/scratch btrfs rw,relatime,space_cache=v2,subvolid=5,subvol=/ 0 0
>
> After:
> $ mkfs.btrfs -fq /dev/vg_fstests/lv1 /dev/sdb > /dev/null
>
> $ blkid --uuid c774b4a6-3ad2-4b15-834a-894dfc898aa9
> /dev/mapper/vg_fstests-lv1
>
> $ mount --verbose /dev/vg_fstests/lv1 /mnt/scratch
> mount: /dev/mapper/vg_fstests-lv1 mounted on /mnt/scratch.
>
> $ cat /proc/self/mounts | grep scratch
> /dev/mapper/vg_fstests-lv1 /mnt/scratch btrfs rw,relatime,space_cache=v2,subvolid=5,subvol=/ 0 0
I do not think this is the correct way to go.
It looks more like a bug in libblkid.
Please explain why the problem happens, not workaround it without any
reasons.
Thanks,
Qu
>
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> Link: https://lore.kernel.org/linux-btrfs/5f401c48-29f5-403e-8c39-50188028ad00@oracle.com/
> ---
> mkfs/main.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/mkfs/main.c b/mkfs/main.c
> index 4c2ce98c784c..e6466d88313a 100644
> --- a/mkfs/main.c
> +++ b/mkfs/main.c
> @@ -1537,7 +1537,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
> }
>
> for (i = 0; i < device_count; i++) {
> - file = argv[optind++];
> + file = path_canonicalize(argv[optind++]);
>
> if (source_dir && path_exists(file) == 0)
> ret = 0;
> @@ -1553,7 +1553,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
> optind = saved_optind;
> device_count = argc - optind;
>
> - file = argv[optind++];
> + file = path_canonicalize(argv[optind++]);
> ssd = device_get_rotational(file);
> if (opt_zoned) {
> if (!zone_size(file)) {
> @@ -1752,7 +1752,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
> for (i = saved_optind; i < saved_optind + device_count; i++) {
> char *path;
>
> - path = argv[i];
> + path = path_canonicalize(argv[i]);
> ret = test_minimum_size(path, min_dev_size);
> if (ret < 0) {
> error("failed to check size for %s: %m", path);
> @@ -1816,7 +1816,8 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
> opt_oflags = O_RDWR;
> for (i = 0; i < device_count; i++) {
> if (opt_zoned &&
> - zoned_model(argv[optind + i - 1]) == ZONED_HOST_MANAGED) {
> + zoned_model(path_canonicalize(argv[optind + i - 1])) ==
> + ZONED_HOST_MANAGED) {
> opt_oflags |= O_DIRECT;
> break;
> }
> @@ -1824,7 +1825,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
>
> /* Start threads */
> for (i = 0; i < device_count; i++) {
> - prepare_ctx[i].file = argv[optind + i - 1];
> + prepare_ctx[i].file = path_canonicalize(argv[optind + i - 1]);
> prepare_ctx[i].byte_count = byte_count;
> prepare_ctx[i].dev_byte_count = byte_count;
> ret = pthread_create(&t_prepare[i], NULL, prepare_one_device,
> @@ -2198,7 +2199,7 @@ out:
> optind = saved_optind;
> device_count = argc - optind;
> while (device_count-- > 0) {
> - file = argv[optind++];
> + file = path_canonicalize(argv[optind++]);
> if (path_is_block_device(file) == 1)
> btrfs_register_one_device(file);
> }
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] btrfs-progs: mkfs: use path_canonicalize for input device
2025-05-16 1:43 ` Qu Wenruo
@ 2025-05-20 10:53 ` Anand Jain
0 siblings, 0 replies; 3+ messages in thread
From: Anand Jain @ 2025-05-20 10:53 UTC (permalink / raw)
To: Qu Wenruo, linux-btrfs
On 16/5/25 09:43, Qu Wenruo wrote:
>
>
> 在 2025/5/15 23:46, Anand Jain 写道:
>> Canonicalize the input device's path before using it.
>> So that we show the device path that matches with the /proc/fs/
>>
>> Before:
>> $ mkfs.btrfs -fq /dev/vg_fstests/lv1 /dev/sdb > /dev/null
>>
>> $ blkid --uuid c3bf2107-292d-4c7f-a288-0fa922ebd71a
>> /dev/mapper/vg_fstests-lv1
>>
>> $ mount --verbose /dev/vg_fstests/lv1 /mnt/scratch
>> mount: /dev/mapper/vg_fstests-lv1 mounted on /mnt/scratch.
>>
>> $ cat /proc/self/mounts | grep scratch
>> /dev/vg_fstests/lv1 /mnt/scratch btrfs
>> rw,relatime,space_cache=v2,subvolid=5,subvol=/ 0 0
>>
>> After:
>> $ mkfs.btrfs -fq /dev/vg_fstests/lv1 /dev/sdb > /dev/null
>>
>> $ blkid --uuid c774b4a6-3ad2-4b15-834a-894dfc898aa9
>> /dev/mapper/vg_fstests-lv1
>>
>> $ mount --verbose /dev/vg_fstests/lv1 /mnt/scratch
>> mount: /dev/mapper/vg_fstests-lv1 mounted on /mnt/scratch.
>>
>> $ cat /proc/self/mounts | grep scratch
>> /dev/mapper/vg_fstests-lv1 /mnt/scratch btrfs
>> rw,relatime,space_cache=v2,subvolid=5,subvol=/ 0 0
>
> I do not think this is the correct way to go.
>
> It looks more like a bug in libblkid.
This is a bug in util-linux, as I've already reported in the Link below.
Before kernel patch 2e8b6bc0ab41 ("btrfs: avoid unnecessary device path
update for the same device"), the mount command could update the device
path. After this patch, such updates are blocked — the path set at
mkfs.btrfs time is now retained. Meanwhile, mount still resolves /dev/
dm-0 to its equivalent /dev/mapper/..., which matches what tools like
findmnt report. So idea in this patch to register with the mapper
device path.
In util-linux 2.37.4, if findmnt's path doesn't match what
show_devname() returns, mount -a (by UUID) fails with -EBUSY. In 2.40.2,
the failure is avoided — but verbose is misleadingly reports
"successfully mounted" even when the device is already mounted. By
contrast, ext4 and xfs behave correctly — they return "already mounted",
which is accurate and expected.
Thanks, Anand
>
> Please explain why the problem happens, not workaround it without any
> reasons.
>
> Thanks,
> Qu
>
>>
>> Signed-off-by: Anand Jain <anand.jain@oracle.com>
>> Link: https://lore.kernel.org/linux-
>> btrfs/5f401c48-29f5-403e-8c39-50188028ad00@oracle.com/
>> ---
>> mkfs/main.c | 13 +++++++------
>> 1 file changed, 7 insertions(+), 6 deletions(-)
>>
>> diff --git a/mkfs/main.c b/mkfs/main.c
>> index 4c2ce98c784c..e6466d88313a 100644
>> --- a/mkfs/main.c
>> +++ b/mkfs/main.c
>> @@ -1537,7 +1537,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
>> }
>> for (i = 0; i < device_count; i++) {
>> - file = argv[optind++];
>> + file = path_canonicalize(argv[optind++]);
>> if (source_dir && path_exists(file) == 0)
>> ret = 0;
>> @@ -1553,7 +1553,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
>> optind = saved_optind;
>> device_count = argc - optind;
>> - file = argv[optind++];
>> + file = path_canonicalize(argv[optind++]);
>> ssd = device_get_rotational(file);
>> if (opt_zoned) {
>> if (!zone_size(file)) {
>> @@ -1752,7 +1752,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
>> for (i = saved_optind; i < saved_optind + device_count; i++) {
>> char *path;
>> - path = argv[i];
>> + path = path_canonicalize(argv[i]);
>> ret = test_minimum_size(path, min_dev_size);
>> if (ret < 0) {
>> error("failed to check size for %s: %m", path);
>> @@ -1816,7 +1816,8 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
>> opt_oflags = O_RDWR;
>> for (i = 0; i < device_count; i++) {
>> if (opt_zoned &&
>> - zoned_model(argv[optind + i - 1]) == ZONED_HOST_MANAGED) {
>> + zoned_model(path_canonicalize(argv[optind + i - 1])) ==
>> + ZONED_HOST_MANAGED) {
>> opt_oflags |= O_DIRECT;
>> break;
>> }
>> @@ -1824,7 +1825,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
>> /* Start threads */
>> for (i = 0; i < device_count; i++) {
>> - prepare_ctx[i].file = argv[optind + i - 1];
>> + prepare_ctx[i].file = path_canonicalize(argv[optind + i - 1]);
>> prepare_ctx[i].byte_count = byte_count;
>> prepare_ctx[i].dev_byte_count = byte_count;
>> ret = pthread_create(&t_prepare[i], NULL, prepare_one_device,
>> @@ -2198,7 +2199,7 @@ out:
>> optind = saved_optind;
>> device_count = argc - optind;
>> while (device_count-- > 0) {
>> - file = argv[optind++];
>> + file = path_canonicalize(argv[optind++]);
>> if (path_is_block_device(file) == 1)
>> btrfs_register_one_device(file);
>> }
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2025-05-20 10:53 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-05-15 14:16 [PATCH] btrfs-progs: mkfs: use path_canonicalize for input device Anand Jain
2025-05-16 1:43 ` Qu Wenruo
2025-05-20 10:53 ` Anand Jain
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox