| Message ID | 1408016420-29221-2-git-send-email-guaneryu@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
Eryu,
btrfs dev scan -d option is there for legacy reasons. The new method
is using libblkid to find btrfs devs.
David/Zach, is it time to remove -d option ? or mention deprecated.
But your test case show problem using btrfsck as well. thats nice!
The fix for this is in the kernel, which would return busy
if the device path is being updated when the device is mounted.
Can you try with Chris integration branch ? mainly the patch..
-------------
commit 4e5c146442b23437d23a2bd81b95f13dfeaffe88
Author: Anand Jain <anand.jain@oracle.com>
Date: Thu Jul 3 18:22:05 2014 +0800
Btrfs: device_list_add() should not update list when mounted
-------------
Thanks, Anand
On 14/08/2014 19:40, Eryu Guan wrote:
> A btrfsck or btrfs device scan -d operation could change the device
> name of other mounted btrfs in kernel, if the other btrfs is on lvm
> device.
>
> Assume that we have two btrfs filesystems, kernel is 3.16.0-rc4+
>
> [root@hp-dl388eg8-01 btrfs-progs]# btrfs fi show
> Label: none uuid: 1aba7da5-ce2b-4af0-a716-db732abc60b2
> Total devices 1 FS bytes used 384.00KiB
> devid 1 size 15.00GiB used 2.04GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv1
>
> Label: none uuid: 26ff4f12-f6d9-4cbc-aae2-57febeefde37
> Total devices 2 FS bytes used 112.00KiB
> devid 1 size 15.00GiB used 2.03GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv2
> devid 2 size 15.00GiB used 2.01GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv3
>
> Btrfs v3.14.2
>
> And testlv1 was mounted at /mnt/btrfs
>
> [root@hp-dl388eg8-01 btrfs-progs]# df -TP /mnt/btrfs
> Filesystem Type 1024-blocks Used Available Capacity Mounted on
> /dev/mapper/rhel_hp--dl388eg8--01-testlv1 btrfs 15728640 512 13602560 1% /mnt/btrfs
>
> Now run btrfsck on testlv2 or btrfs device scan -d, which will scan
> all btrfs devices and somehow change the device name.
>
> [root@hp-dl388eg8-01 btrfs-progs]# btrfsck /dev/mapper/rhel_hp--dl388eg8--01-testlv2 >/dev/null 2>&1
>
> [root@hp-dl388eg8-01 btrfs-progs]# df -TP /mnt/btrfs
> Filesystem Type 1024-blocks Used Available Capacity Mounted on
> /dev/dm-3 btrfs 15728640 512 13602560 1% /mnt/btrfs
> [root@hp-dl388eg8-01 btrfs-progs]# btrfs fi show
> Label: none uuid: 1aba7da5-ce2b-4af0-a716-db732abc60b2
> Total devices 1 FS bytes used 384.00KiB
> devid 1 size 15.00GiB used 2.04GiB path /dev/dm-3
>
> Label: none uuid: 26ff4f12-f6d9-4cbc-aae2-57febeefde37
> Total devices 2 FS bytes used 112.00KiB
> devid 1 size 15.00GiB used 2.03GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv2
> devid 2 size 15.00GiB used 2.01GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv3
>
> Btrfs v3.14.2
>
> Now calling btrfs_register_one_device with canonicalized dm device name.
>
> Signed-off-by: Eryu Guan <guaneryu@gmail.com>
> ---
>
> With patch 1 applied, btrfsck won't change the device name,
> but btrfs device scan -d still does.
>
> utils.c | 44 +++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 41 insertions(+), 3 deletions(-)
>
> diff --git a/utils.c b/utils.c
> index f54e749..3567094 100644
> --- a/utils.c
> +++ b/utils.c
> @@ -985,6 +985,32 @@ static int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices,
> }
>
> /*
> + * Convert dm-N device name to /dev/mapper/name
> + */
> +static void canonicalize_dm_name(char *devnode, char *path, int len)
> +{
> + char *buf = NULL;
> + FILE *sysfsp = NULL;
> +
> + buf = malloc(PATH_MAX);
> + if (!buf)
> + return;
> +
> + snprintf(buf, PATH_MAX, "/sys/block/%s/dm/name", devnode);
> + sysfsp = fopen(buf, "r");
> + if (!sysfsp)
> + goto out;
> +
> + if (fgets(buf, PATH_MAX, sysfsp)) {
> + buf[strlen(buf) - 1] = '\0';
> + snprintf(path, len - 1, "/dev/mapper/%s", buf);
> + }
> + fclose(sysfsp);
> +out:
> + free(buf);
> +}
> +
> +/*
> * returns 1 if the device was mounted, < 0 on error or 0 if everything
> * is safe to continue.
> */
> @@ -1189,6 +1215,9 @@ again:
> if (fsid && memcmp(fsid, tmp_devices->fsid, BTRFS_FSID_SIZE))
> continue;
> if (run_ioctl > 0) {
> + if (!strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-")))
> + canonicalize_dm_name(dirent->d_name,
> + fullpath, PATH_MAX);
> btrfs_register_one_device(fullpath);
> }
> close(fd);
> @@ -1475,8 +1504,11 @@ int btrfs_scan_block_devices(u8 *fsid, int run_ioctl)
> int i;
> char buf[1024];
> char fullpath[110];
> + char devnode[64];
> + char *dirname = "/dev/";
> int scans = 0;
> int special;
> + int is_dm;
>
> scan_again:
> proc_partitions = fopen("/proc/partitions","r");
> @@ -1493,9 +1525,11 @@ scan_again:
> return -ENOENT;
> }
>
> - strcpy(fullpath,"/dev/");
> - while(fgets(buf, 1023, proc_partitions)) {
> - i = sscanf(buf," %*d %*d %*d %99s", fullpath+5);
> + strcpy(fullpath, dirname);
> + while (fgets(buf, sizeof(buf) - 1, proc_partitions)) {
> + i = sscanf(buf, " %*d %*d %*d %99s", devnode);
> + strncpy(fullpath + strlen(dirname), devnode,
> + sizeof(fullpath) - strlen(dirname));
>
> /*
> * multipath and MD devices may register as a btrfs filesystem
> @@ -1504,6 +1538,7 @@ scan_again:
> * This scans the special entries last
> */
> special = strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-")) == 0;
> + is_dm = special;
> if (!special)
> special = strncmp(fullpath, "/dev/md", strlen("/dev/md")) == 0;
>
> @@ -1538,6 +1573,9 @@ scan_again:
> if (fsid && memcmp(fsid, tmp_devices->fsid, BTRFS_FSID_SIZE))
> continue;
> if (run_ioctl > 0) {
> + if (is_dm)
> + canonicalize_dm_name(devnode, fullpath,
> + sizeof(fullpath));
> btrfs_register_one_device(fullpath);
> }
> }
>
--
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On Fri, Aug 15, 2014 at 09:50:34AM +0800, Anand Jain wrote: > > Eryu, > > btrfs dev scan -d option is there for legacy reasons. The new method > is using libblkid to find btrfs devs. > > David/Zach, is it time to remove -d option ? or mention deprecated. > > > But your test case show problem using btrfsck as well. thats nice! > The fix for this is in the kernel, which would return busy > if the device path is being updated when the device is mounted. > Can you try with Chris integration branch ? mainly the patch.. > > ------------- > commit 4e5c146442b23437d23a2bd81b95f13dfeaffe88 > Author: Anand Jain <anand.jain@oracle.com> > Date: Thu Jul 3 18:22:05 2014 +0800 > > Btrfs: device_list_add() should not update list when mounted > ------------- Thanks Anand, this patch fixed the issue, btrfsck reports "Device or resource busy" now. [root@hp-dl388g8-01 ~]# btrfsck /dev/mapper/rhel_hp--dl388g8--01-btrfs--2 ERROR: device scan failed '/dev/dm-3' - Device or resource busy Checking filesystem on /dev/mapper/rhel_hp--dl388g8--01-btrfs--2 UUID: 1104d6d6-2653-496b-8d67-184d522dd632 checking extents checking free space cache cache and super generation don't match, space cache will be invalidated checking fs roots checking csums checking root refs found 114688 bytes used err is 0 total csum bytes: 0 total tree bytes: 114688 total fs tree bytes: 32768 total extent tree bytes: 16384 btree space waste bytes: 108436 file data blocks allocated: 0 referenced 0 Btrfs v3.12 But btrfsck is still scanning unrelated devices when checking a btrfs with multiple devices. In my case, I was checking btrfs on lv btrfs-2, but btrfs-1(dm-3) was scanned too. Hope my first patch could fix this issue in an expected way. Thanks, Eryu > > > Thanks, Anand > > > On 14/08/2014 19:40, Eryu Guan wrote: > >A btrfsck or btrfs device scan -d operation could change the device > >name of other mounted btrfs in kernel, if the other btrfs is on lvm > >device. > > > >Assume that we have two btrfs filesystems, kernel is 3.16.0-rc4+ > > > >[root@hp-dl388eg8-01 btrfs-progs]# btrfs fi show > >Label: none uuid: 1aba7da5-ce2b-4af0-a716-db732abc60b2 > > Total devices 1 FS bytes used 384.00KiB > > devid 1 size 15.00GiB used 2.04GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv1 > > > >Label: none uuid: 26ff4f12-f6d9-4cbc-aae2-57febeefde37 > > Total devices 2 FS bytes used 112.00KiB > > devid 1 size 15.00GiB used 2.03GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv2 > > devid 2 size 15.00GiB used 2.01GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv3 > > > >Btrfs v3.14.2 > > > >And testlv1 was mounted at /mnt/btrfs > > > >[root@hp-dl388eg8-01 btrfs-progs]# df -TP /mnt/btrfs > >Filesystem Type 1024-blocks Used Available Capacity Mounted on > >/dev/mapper/rhel_hp--dl388eg8--01-testlv1 btrfs 15728640 512 13602560 1% /mnt/btrfs > > > >Now run btrfsck on testlv2 or btrfs device scan -d, which will scan > >all btrfs devices and somehow change the device name. > > > >[root@hp-dl388eg8-01 btrfs-progs]# btrfsck /dev/mapper/rhel_hp--dl388eg8--01-testlv2 >/dev/null 2>&1 > > > >[root@hp-dl388eg8-01 btrfs-progs]# df -TP /mnt/btrfs > >Filesystem Type 1024-blocks Used Available Capacity Mounted on > >/dev/dm-3 btrfs 15728640 512 13602560 1% /mnt/btrfs > >[root@hp-dl388eg8-01 btrfs-progs]# btrfs fi show > >Label: none uuid: 1aba7da5-ce2b-4af0-a716-db732abc60b2 > > Total devices 1 FS bytes used 384.00KiB > > devid 1 size 15.00GiB used 2.04GiB path /dev/dm-3 > > > >Label: none uuid: 26ff4f12-f6d9-4cbc-aae2-57febeefde37 > > Total devices 2 FS bytes used 112.00KiB > > devid 1 size 15.00GiB used 2.03GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv2 > > devid 2 size 15.00GiB used 2.01GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv3 > > > >Btrfs v3.14.2 > > > >Now calling btrfs_register_one_device with canonicalized dm device name. > > > >Signed-off-by: Eryu Guan <guaneryu@gmail.com> > >--- > > > >With patch 1 applied, btrfsck won't change the device name, > >but btrfs device scan -d still does. > > > > utils.c | 44 +++++++++++++++++++++++++++++++++++++++++--- > > 1 file changed, 41 insertions(+), 3 deletions(-) > > > >diff --git a/utils.c b/utils.c > >index f54e749..3567094 100644 > >--- a/utils.c > >+++ b/utils.c > >@@ -985,6 +985,32 @@ static int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices, > > } > > > > /* > >+ * Convert dm-N device name to /dev/mapper/name > >+ */ > >+static void canonicalize_dm_name(char *devnode, char *path, int len) > >+{ > >+ char *buf = NULL; > >+ FILE *sysfsp = NULL; > >+ > >+ buf = malloc(PATH_MAX); > >+ if (!buf) > >+ return; > >+ > >+ snprintf(buf, PATH_MAX, "/sys/block/%s/dm/name", devnode); > >+ sysfsp = fopen(buf, "r"); > >+ if (!sysfsp) > >+ goto out; > >+ > >+ if (fgets(buf, PATH_MAX, sysfsp)) { > >+ buf[strlen(buf) - 1] = '\0'; > >+ snprintf(path, len - 1, "/dev/mapper/%s", buf); > >+ } > >+ fclose(sysfsp); > >+out: > >+ free(buf); > >+} > >+ > >+/* > > * returns 1 if the device was mounted, < 0 on error or 0 if everything > > * is safe to continue. > > */ > >@@ -1189,6 +1215,9 @@ again: > > if (fsid && memcmp(fsid, tmp_devices->fsid, BTRFS_FSID_SIZE)) > > continue; > > if (run_ioctl > 0) { > >+ if (!strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-"))) > >+ canonicalize_dm_name(dirent->d_name, > >+ fullpath, PATH_MAX); > > btrfs_register_one_device(fullpath); > > } > > close(fd); > >@@ -1475,8 +1504,11 @@ int btrfs_scan_block_devices(u8 *fsid, int run_ioctl) > > int i; > > char buf[1024]; > > char fullpath[110]; > >+ char devnode[64]; > >+ char *dirname = "/dev/"; > > int scans = 0; > > int special; > >+ int is_dm; > > > > scan_again: > > proc_partitions = fopen("/proc/partitions","r"); > >@@ -1493,9 +1525,11 @@ scan_again: > > return -ENOENT; > > } > > > >- strcpy(fullpath,"/dev/"); > >- while(fgets(buf, 1023, proc_partitions)) { > >- i = sscanf(buf," %*d %*d %*d %99s", fullpath+5); > >+ strcpy(fullpath, dirname); > >+ while (fgets(buf, sizeof(buf) - 1, proc_partitions)) { > >+ i = sscanf(buf, " %*d %*d %*d %99s", devnode); > >+ strncpy(fullpath + strlen(dirname), devnode, > >+ sizeof(fullpath) - strlen(dirname)); > > > > /* > > * multipath and MD devices may register as a btrfs filesystem > >@@ -1504,6 +1538,7 @@ scan_again: > > * This scans the special entries last > > */ > > special = strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-")) == 0; > >+ is_dm = special; > > if (!special) > > special = strncmp(fullpath, "/dev/md", strlen("/dev/md")) == 0; > > > >@@ -1538,6 +1573,9 @@ scan_again: > > if (fsid && memcmp(fsid, tmp_devices->fsid, BTRFS_FSID_SIZE)) > > continue; > > if (run_ioctl > 0) { > >+ if (is_dm) > >+ canonicalize_dm_name(devnode, fullpath, > >+ sizeof(fullpath)); > > btrfs_register_one_device(fullpath); > > } > > } > > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 15/08/2014 12:30, Eryu Guan wrote: > On Fri, Aug 15, 2014 at 09:50:34AM +0800, Anand Jain wrote: >> >> Eryu, >> >> btrfs dev scan -d option is there for legacy reasons. The new method >> is using libblkid to find btrfs devs. >> >> David/Zach, is it time to remove -d option ? or mention deprecated. >> >> >> But your test case show problem using btrfsck as well. thats nice! >> The fix for this is in the kernel, which would return busy >> if the device path is being updated when the device is mounted. >> Can you try with Chris integration branch ? mainly the patch.. >> >> ------------- >> commit 4e5c146442b23437d23a2bd81b95f13dfeaffe88 >> Author: Anand Jain <anand.jain@oracle.com> >> Date: Thu Jul 3 18:22:05 2014 +0800 >> >> Btrfs: device_list_add() should not update list when mounted >> ------------- > > Thanks Anand, this patch fixed the issue, btrfsck reports "Device or > resource busy" now. Thanks for testing. > [root@hp-dl388g8-01 ~]# btrfsck /dev/mapper/rhel_hp--dl388g8--01-btrfs--2 > ERROR: device scan failed '/dev/dm-3' - Device or resource busy > Checking filesystem on /dev/mapper/rhel_hp--dl388g8--01-btrfs--2 > UUID: 1104d6d6-2653-496b-8d67-184d522dd632 > checking extents > checking free space cache > cache and super generation don't match, space cache will be invalidated > checking fs roots > checking csums > checking root refs > found 114688 bytes used err is 0 > total csum bytes: 0 > total tree bytes: 114688 > total fs tree bytes: 32768 > total extent tree bytes: 16384 > btree space waste bytes: 108436 > file data blocks allocated: 0 > referenced 0 > Btrfs v3.12 > > But btrfsck is still scanning unrelated devices when checking a btrfs > with multiple devices. In my case, I was checking btrfs on lv btrfs-2, > but btrfs-1(dm-3) was scanned too. That's expected, as of now the only way to find a partner device is by scanning the available devices. Anand > Hope my first patch could fix this issue in an expected way. > > Thanks, > Eryu >> >> >> Thanks, Anand >> >> >> On 14/08/2014 19:40, Eryu Guan wrote: >>> A btrfsck or btrfs device scan -d operation could change the device >>> name of other mounted btrfs in kernel, if the other btrfs is on lvm >>> device. >>> >>> Assume that we have two btrfs filesystems, kernel is 3.16.0-rc4+ >>> >>> [root@hp-dl388eg8-01 btrfs-progs]# btrfs fi show >>> Label: none uuid: 1aba7da5-ce2b-4af0-a716-db732abc60b2 >>> Total devices 1 FS bytes used 384.00KiB >>> devid 1 size 15.00GiB used 2.04GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv1 >>> >>> Label: none uuid: 26ff4f12-f6d9-4cbc-aae2-57febeefde37 >>> Total devices 2 FS bytes used 112.00KiB >>> devid 1 size 15.00GiB used 2.03GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv2 >>> devid 2 size 15.00GiB used 2.01GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv3 >>> >>> Btrfs v3.14.2 >>> >>> And testlv1 was mounted at /mnt/btrfs >>> >>> [root@hp-dl388eg8-01 btrfs-progs]# df -TP /mnt/btrfs >>> Filesystem Type 1024-blocks Used Available Capacity Mounted on >>> /dev/mapper/rhel_hp--dl388eg8--01-testlv1 btrfs 15728640 512 13602560 1% /mnt/btrfs >>> >>> Now run btrfsck on testlv2 or btrfs device scan -d, which will scan >>> all btrfs devices and somehow change the device name. >>> >>> [root@hp-dl388eg8-01 btrfs-progs]# btrfsck /dev/mapper/rhel_hp--dl388eg8--01-testlv2 >/dev/null 2>&1 >>> >>> [root@hp-dl388eg8-01 btrfs-progs]# df -TP /mnt/btrfs >>> Filesystem Type 1024-blocks Used Available Capacity Mounted on >>> /dev/dm-3 btrfs 15728640 512 13602560 1% /mnt/btrfs >>> [root@hp-dl388eg8-01 btrfs-progs]# btrfs fi show >>> Label: none uuid: 1aba7da5-ce2b-4af0-a716-db732abc60b2 >>> Total devices 1 FS bytes used 384.00KiB >>> devid 1 size 15.00GiB used 2.04GiB path /dev/dm-3 >>> >>> Label: none uuid: 26ff4f12-f6d9-4cbc-aae2-57febeefde37 >>> Total devices 2 FS bytes used 112.00KiB >>> devid 1 size 15.00GiB used 2.03GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv2 >>> devid 2 size 15.00GiB used 2.01GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv3 >>> >>> Btrfs v3.14.2 >>> >>> Now calling btrfs_register_one_device with canonicalized dm device name. >>> >>> Signed-off-by: Eryu Guan <guaneryu@gmail.com> >>> --- >>> >>> With patch 1 applied, btrfsck won't change the device name, >>> but btrfs device scan -d still does. >>> >>> utils.c | 44 +++++++++++++++++++++++++++++++++++++++++--- >>> 1 file changed, 41 insertions(+), 3 deletions(-) >>> >>> diff --git a/utils.c b/utils.c >>> index f54e749..3567094 100644 >>> --- a/utils.c >>> +++ b/utils.c >>> @@ -985,6 +985,32 @@ static int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices, >>> } >>> >>> /* >>> + * Convert dm-N device name to /dev/mapper/name >>> + */ >>> +static void canonicalize_dm_name(char *devnode, char *path, int len) >>> +{ >>> + char *buf = NULL; >>> + FILE *sysfsp = NULL; >>> + >>> + buf = malloc(PATH_MAX); >>> + if (!buf) >>> + return; >>> + >>> + snprintf(buf, PATH_MAX, "/sys/block/%s/dm/name", devnode); >>> + sysfsp = fopen(buf, "r"); >>> + if (!sysfsp) >>> + goto out; >>> + >>> + if (fgets(buf, PATH_MAX, sysfsp)) { >>> + buf[strlen(buf) - 1] = '\0'; >>> + snprintf(path, len - 1, "/dev/mapper/%s", buf); >>> + } >>> + fclose(sysfsp); >>> +out: >>> + free(buf); >>> +} >>> + >>> +/* >>> * returns 1 if the device was mounted, < 0 on error or 0 if everything >>> * is safe to continue. >>> */ >>> @@ -1189,6 +1215,9 @@ again: >>> if (fsid && memcmp(fsid, tmp_devices->fsid, BTRFS_FSID_SIZE)) >>> continue; >>> if (run_ioctl > 0) { >>> + if (!strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-"))) >>> + canonicalize_dm_name(dirent->d_name, >>> + fullpath, PATH_MAX); >>> btrfs_register_one_device(fullpath); >>> } >>> close(fd); >>> @@ -1475,8 +1504,11 @@ int btrfs_scan_block_devices(u8 *fsid, int run_ioctl) >>> int i; >>> char buf[1024]; >>> char fullpath[110]; >>> + char devnode[64]; >>> + char *dirname = "/dev/"; >>> int scans = 0; >>> int special; >>> + int is_dm; >>> >>> scan_again: >>> proc_partitions = fopen("/proc/partitions","r"); >>> @@ -1493,9 +1525,11 @@ scan_again: >>> return -ENOENT; >>> } >>> >>> - strcpy(fullpath,"/dev/"); >>> - while(fgets(buf, 1023, proc_partitions)) { >>> - i = sscanf(buf," %*d %*d %*d %99s", fullpath+5); >>> + strcpy(fullpath, dirname); >>> + while (fgets(buf, sizeof(buf) - 1, proc_partitions)) { >>> + i = sscanf(buf, " %*d %*d %*d %99s", devnode); >>> + strncpy(fullpath + strlen(dirname), devnode, >>> + sizeof(fullpath) - strlen(dirname)); >>> >>> /* >>> * multipath and MD devices may register as a btrfs filesystem >>> @@ -1504,6 +1538,7 @@ scan_again: >>> * This scans the special entries last >>> */ >>> special = strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-")) == 0; >>> + is_dm = special; >>> if (!special) >>> special = strncmp(fullpath, "/dev/md", strlen("/dev/md")) == 0; >>> >>> @@ -1538,6 +1573,9 @@ scan_again: >>> if (fsid && memcmp(fsid, tmp_devices->fsid, BTRFS_FSID_SIZE)) >>> continue; >>> if (run_ioctl > 0) { >>> + if (is_dm) >>> + canonicalize_dm_name(devnode, fullpath, >>> + sizeof(fullpath)); >>> btrfs_register_one_device(fullpath); >>> } >>> } >>> > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Aug 14, 2014 at 07:40:20PM +0800, Eryu Guan wrote: > [root@hp-dl388eg8-01 btrfs-progs]# btrfs fi show > Label: none uuid: 1aba7da5-ce2b-4af0-a716-db732abc60b2 > Total devices 1 FS bytes used 384.00KiB > devid 1 size 15.00GiB used 2.04GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv1 > > Label: none uuid: 26ff4f12-f6d9-4cbc-aae2-57febeefde37 > Total devices 2 FS bytes used 112.00KiB > devid 1 size 15.00GiB used 2.03GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv2 > devid 2 size 15.00GiB used 2.01GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv3 > > Btrfs v3.14.2 The commit b276e4bc50b6ca99056a45315ea859c68d58fc1b "canonicalize pathnames for device commands" supposedly fixes the same problem, added in 3.16. Can you please test that it works in your case as well? Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Sep 02, 2014 at 01:32:34PM +0200, David Sterba wrote: > On Thu, Aug 14, 2014 at 07:40:20PM +0800, Eryu Guan wrote: > > [root@hp-dl388eg8-01 btrfs-progs]# btrfs fi show > > Label: none uuid: 1aba7da5-ce2b-4af0-a716-db732abc60b2 > > Total devices 1 FS bytes used 384.00KiB > > devid 1 size 15.00GiB used 2.04GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv1 > > > > Label: none uuid: 26ff4f12-f6d9-4cbc-aae2-57febeefde37 > > Total devices 2 FS bytes used 112.00KiB > > devid 1 size 15.00GiB used 2.03GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv2 > > devid 2 size 15.00GiB used 2.01GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv3 > > > > Btrfs v3.14.2 > > The commit b276e4bc50b6ca99056a45315ea859c68d58fc1b > "canonicalize pathnames for device commands" supposedly fixes the same > problem, added in 3.16. Can you please test that it works in your case > as well? Thanks. Yes, confirmed v3.16 fixes the issue, the device name didn't change after btrfsck and btrfs device scan -d Thanks, Eryu -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/utils.c b/utils.c index f54e749..3567094 100644 --- a/utils.c +++ b/utils.c @@ -985,6 +985,32 @@ static int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices, } /* + * Convert dm-N device name to /dev/mapper/name + */ +static void canonicalize_dm_name(char *devnode, char *path, int len) +{ + char *buf = NULL; + FILE *sysfsp = NULL; + + buf = malloc(PATH_MAX); + if (!buf) + return; + + snprintf(buf, PATH_MAX, "/sys/block/%s/dm/name", devnode); + sysfsp = fopen(buf, "r"); + if (!sysfsp) + goto out; + + if (fgets(buf, PATH_MAX, sysfsp)) { + buf[strlen(buf) - 1] = '\0'; + snprintf(path, len - 1, "/dev/mapper/%s", buf); + } + fclose(sysfsp); +out: + free(buf); +} + +/* * returns 1 if the device was mounted, < 0 on error or 0 if everything * is safe to continue. */ @@ -1189,6 +1215,9 @@ again: if (fsid && memcmp(fsid, tmp_devices->fsid, BTRFS_FSID_SIZE)) continue; if (run_ioctl > 0) { + if (!strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-"))) + canonicalize_dm_name(dirent->d_name, + fullpath, PATH_MAX); btrfs_register_one_device(fullpath); } close(fd); @@ -1475,8 +1504,11 @@ int btrfs_scan_block_devices(u8 *fsid, int run_ioctl) int i; char buf[1024]; char fullpath[110]; + char devnode[64]; + char *dirname = "/dev/"; int scans = 0; int special; + int is_dm; scan_again: proc_partitions = fopen("/proc/partitions","r"); @@ -1493,9 +1525,11 @@ scan_again: return -ENOENT; } - strcpy(fullpath,"/dev/"); - while(fgets(buf, 1023, proc_partitions)) { - i = sscanf(buf," %*d %*d %*d %99s", fullpath+5); + strcpy(fullpath, dirname); + while (fgets(buf, sizeof(buf) - 1, proc_partitions)) { + i = sscanf(buf, " %*d %*d %*d %99s", devnode); + strncpy(fullpath + strlen(dirname), devnode, + sizeof(fullpath) - strlen(dirname)); /* * multipath and MD devices may register as a btrfs filesystem @@ -1504,6 +1538,7 @@ scan_again: * This scans the special entries last */ special = strncmp(fullpath, "/dev/dm-", strlen("/dev/dm-")) == 0; + is_dm = special; if (!special) special = strncmp(fullpath, "/dev/md", strlen("/dev/md")) == 0; @@ -1538,6 +1573,9 @@ scan_again: if (fsid && memcmp(fsid, tmp_devices->fsid, BTRFS_FSID_SIZE)) continue; if (run_ioctl > 0) { + if (is_dm) + canonicalize_dm_name(devnode, fullpath, + sizeof(fullpath)); btrfs_register_one_device(fullpath); } }
A btrfsck or btrfs device scan -d operation could change the device name of other mounted btrfs in kernel, if the other btrfs is on lvm device. Assume that we have two btrfs filesystems, kernel is 3.16.0-rc4+ [root@hp-dl388eg8-01 btrfs-progs]# btrfs fi show Label: none uuid: 1aba7da5-ce2b-4af0-a716-db732abc60b2 Total devices 1 FS bytes used 384.00KiB devid 1 size 15.00GiB used 2.04GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv1 Label: none uuid: 26ff4f12-f6d9-4cbc-aae2-57febeefde37 Total devices 2 FS bytes used 112.00KiB devid 1 size 15.00GiB used 2.03GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv2 devid 2 size 15.00GiB used 2.01GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv3 Btrfs v3.14.2 And testlv1 was mounted at /mnt/btrfs [root@hp-dl388eg8-01 btrfs-progs]# df -TP /mnt/btrfs Filesystem Type 1024-blocks Used Available Capacity Mounted on /dev/mapper/rhel_hp--dl388eg8--01-testlv1 btrfs 15728640 512 13602560 1% /mnt/btrfs Now run btrfsck on testlv2 or btrfs device scan -d, which will scan all btrfs devices and somehow change the device name. [root@hp-dl388eg8-01 btrfs-progs]# btrfsck /dev/mapper/rhel_hp--dl388eg8--01-testlv2 >/dev/null 2>&1 [root@hp-dl388eg8-01 btrfs-progs]# df -TP /mnt/btrfs Filesystem Type 1024-blocks Used Available Capacity Mounted on /dev/dm-3 btrfs 15728640 512 13602560 1% /mnt/btrfs [root@hp-dl388eg8-01 btrfs-progs]# btrfs fi show Label: none uuid: 1aba7da5-ce2b-4af0-a716-db732abc60b2 Total devices 1 FS bytes used 384.00KiB devid 1 size 15.00GiB used 2.04GiB path /dev/dm-3 Label: none uuid: 26ff4f12-f6d9-4cbc-aae2-57febeefde37 Total devices 2 FS bytes used 112.00KiB devid 1 size 15.00GiB used 2.03GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv2 devid 2 size 15.00GiB used 2.01GiB path /dev/mapper/rhel_hp--dl388eg8--01-testlv3 Btrfs v3.14.2 Now calling btrfs_register_one_device with canonicalized dm device name. Signed-off-by: Eryu Guan <guaneryu@gmail.com> --- With patch 1 applied, btrfsck won't change the device name, but btrfs device scan -d still does. utils.c | 44 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 41 insertions(+), 3 deletions(-)