libxfs: detect zoned disks and prevent their raw use
PATCH 1/1 libxfs: detect zoned disks and prevent their raw use
Using raw zoned disks by filesystems requires special handling, only f2fs currently supports this. All other filesystems do not support dealing with zoned disks directly.
As such using raw zoned disks is not supported by XFS, to use them you need to use dm-zoned-tools, format them with dzadm, set the scheduler to deadline, and then setup a dmsetup with zoned type, and somehow set this up on every boot to live a semi-happy life for now.
Even if you use dmsetup on every boot, the zoned disk is still exposed, and a user may still think they have to run mkfs.xfs on it instead of the /dev/mapper/ disk, and then mount it by mistake.
In either case you may seem to believe your disk works and only eventually end up with alignmet issues and perhaps lose you data. For instance:
[10869.959501] device-mapper: zoned reclaim: (sda): Align zone 865 wp 28349 to 30842 (wp+2493) blocks failed -5 [10870.014488] sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [10870.016137] sd 0:0:0:0: [sda] tag#0 Sense Key : Illegal Request [current] [10870.017696] sd 0:0:0:0: [sda] tag#0 Add. Sense: Unaligned write command
We have to prevent these mistakes by avoiding mkfs.xfs use on zoned disks.
Note that this not enough yet, if users are on old AHCI controllers, the disks may not be detected as zoned. More work through udev may be required to detect this situation old old parent PCI IDs for zoned disks, and then prevent their use somehow.
If you are stuck on using XFS there a udev rule out there [0], this is far from perfect, and not fully what we want done upstream on Linux distributions long term but it should at least help developers for now enjoy their shiny big fat zoned disks with XFS.
This check should help avoid having folks shoot themselves in the foot for now with zoned disks. If you make the mistake to use mkfs.xfs on a zoned disk, you will now get:
# mkfs.xfs /dev/sda /dev/sda: zoned disk detected, refer to dm-zoned-tools for how to use with XFS
[0] https://lkml.kernel.org/r/[email protected]
--- libxfs/init.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+)
libxfs/init.c +41 -0
@@ -98,6 +98,32 @@ libxfs_device_to_fd(dev_t device)/* NOTREACHED */ } +static int +is_zoned_disk (char *path) +{ +char str[PATH_MAX ]; +char *devname =basename (path); +FILE *file; +int len; + + + len =snprintf (str,sizeof (str),"/sys/block/%s/queue/zoned" , devname); + +/* Indicates truncation */ +if (len >=PATH_MAX ) { + errno =ENAMETOOLONG ; +return -1 ; + } + + file =fopen (str,"r" ); +if (!file) +return 0 ; + +fclose (file); + +return 1 ; +} +/* libxfs_device_open: * open a device and return its device number */
@@ -108,6 +134,7 @@ libxfs_device_open(char *path, int creat, int xflags, int setblksize)int fd, d, flags;int readonly, dio, excl;struct stat statb; +int ret; readonly = (xflags &LIBXFS_ISREADONLY ); excl = (xflags &LIBXFS_EXCLUSIVELY ) && !creat;
@@ -119,6 +146,20 @@ retry: (dio ?O_DIRECT :0 ) | \ (excl ?O_EXCL :0 ); + ret =is_zoned_disk (path); +if (ret <0 ) { +fprintf (stderr,_ ("%s: error opening %s\n" ), + path,strerror (errno)); +exit (1 ); + } + +if (ret ==1 ) { +fprintf (stderr, +_ ("%s: zoned disk detected, refer to dm-zoned-tools for how to use with XFS\n" ), + path); +exit (1 ); + } +if ((fd =open (path, flags,0666 )) <0 ) {if (errno ==EINVAL && --dio ==0 ) goto retry;
Signature · 1 line
2.17.1
libxfs/init.c libxfs_device_to_fd(dev_t device) · line 110
Quoted 10 lines · Luis R. Rodriguez
libxfs/init.c +10
-0+static int +is_zoned_disk (char *path) +{ +char str[PATH_MAX ]; +char *devname =basename (path); +FILE *file; +int len; + + + len =snprintf (str,sizeof (str),"/sys/block/%s/queue/zoned" , devname);
Have you considered to use asprintf() instead of using snprintf() and a fixed size buffer?
Quoted 5 lines
libxfs/init.c +5
-0+ +/* Indicates truncation */ +if (len >=PATH_MAX ) { + errno =ENAMETOOLONG ; +return -1 ;
libxfs/init.c libxfs_device_to_fd(dev_t device) · line 125
Quoted 10 lines
libxfs/init.c +10
-0+ } + + file =fopen (str,"r" ); +if (!file) +return 0 ; + +fclose (file); + +return 1 ; +}
I think that you have to read the sysfs file and only return 1 for host-managed drives. Creating a filesystem on top of a host-aware drive should not be forbidden. Please also rename "is_zoned_disk()" into "is_host_managed()" or so.
Thanks,
Bart.
Quoted 68 lines · Luis R. Rodriguez
Using raw zoned disks by filesystems requires special handling, only f2fs currently supports this. All other filesystems do not support dealing with zoned disks directly.
As such using raw zoned disks is not supported by XFS, to use them you need to use dm-zoned-tools, format them with dzadm, set the scheduler to deadline, and then setup a dmsetup with zoned type, and somehow set this up on every boot to live a semi-happy life for now.
Even if you use dmsetup on every boot, the zoned disk is still exposed, and a user may still think they have to run mkfs.xfs on it instead of the
/dev/mapper/disk, and then mount it by mistake.In either case you may seem to believe your disk works and only eventually end up with alignmet issues and perhaps lose you data. For instance:
[10869.959501] device-mapper: zoned reclaim: (sda): Align zone 865 wp 28349 to 30842 (wp+2493) blocks failed -5 [10870.014488] sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [10870.016137] sd 0:0:0:0: [sda] tag#0 Sense Key : Illegal Request [current] [10870.017696] sd 0:0:0:0: [sda] tag#0 Add. Sense: Unaligned write commandWe have to prevent these mistakes by avoiding mkfs.xfs use on zoned disks.
Note that this not enough yet, if users are on old AHCI controllers, the disks may not be detected as zoned. More work through udev may be required to detect this situation old old parent PCI IDs for zoned disks, and then prevent their use somehow.
If you are stuck on using XFS there a udev rule out there [0], this is far from perfect, and not fully what we want done upstream on Linux distributions long term but it should at least help developers for now enjoy their shiny big fat zoned disks with XFS.
This check should help avoid having folks shoot themselves in the foot for now with zoned disks. If you make the mistake to use mkfs.xfs on a zoned disk, you will now get:
# mkfs.xfs /dev/sda /dev/sda: zoned disk detected, refer to dm-zoned-tools for how to use with XFS[0] https://lkml.kernel.org/r/[email protected]
Cc Damien Le Moal <[email protected]>Cc Bart Van Assche <[email protected]>Signed-off-by Luis R. Rodriguez <[email protected]>--- libxfs/init.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+)libxfs/init.c +11
-0@@ -98,6 +98,32 @@ libxfs_device_to_fd(dev_t device)/* NOTREACHED */ } +static int +is_zoned_disk (char *path) +{ +char str[PATH_MAX ]; +char *devname =basename (path); +FILE *file; +int len; + + + len =snprintf (str,sizeof (str),"/sys/block/%s/queue/zoned" , devname); +
libxfs/init.c libxfs_device_to_fd(dev_t device) · line 121
Quoted 10 lines
libxfs/init.c +10
-0+/* Indicates truncation */ +if (len >=PATH_MAX ) { + errno =ENAMETOOLONG ; +return -1 ; + } + + file =fopen (str,"r" ); +if (!file) +return 0 ; +
Shouldn't we read the *file contents and return 0 if the contents are 'none'?
$ lsscsi [0:0:0:0] disk ATA Samsung SSD 850 1B6Q /dev/sda $ cat /sys/block/sda/queue/zoned none
--D
Quoted 44 lines
libxfs/init.c +20
-0+fclose (file); + +return 1 ; +} +/* libxfs_device_open: * open a device and return its device number */ @@ -108,6 +134,7 @@ libxfs_device_open(char *path, int creat, int xflags, int setblksize)int fd, d, flags;int readonly, dio, excl;struct stat statb; +int ret; readonly = (xflags &LIBXFS_ISREADONLY ); excl = (xflags &LIBXFS_EXCLUSIVELY ) && !creat;@@ -119,6 +146,20 @@ retry: (dio ?O_DIRECT :0 ) | \ (excl ?O_EXCL :0 ); + ret =is_zoned_disk (path); +if (ret <0 ) { +fprintf (stderr,_ ("%s: error opening %s\n" ), + path,strerror (errno)); +exit (1 ); + } + +if (ret ==1 ) { +fprintf (stderr, +_ ("%s: zoned disk detected, refer to dm-zoned-tools for how to use with XFS\n" ), + path); +exit (1 ); + } +if ((fd =open (path, flags,0666 )) <0 ) {if (errno ==EINVAL && --dio ==0 ) goto retry;Signature · 6 lines
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libxfs/init.c retry: · line 160
Quoted 5 lines · Luis R. Rodriguez
libxfs/init.c +5
-0+if (ret ==1 ) { +fprintf (stderr, +_ ("%s: zoned disk detected, refer to dm-zoned-tools for how to use with XFS\n" ), + path); +exit (1 );
Sorry for not sending this before V2, but is "dm-zoned-tools" established enough in the ecosystem at this point to embed it in help text of utilities like this?
(It's not in debian or in fedora, so that message might lead to some head-scratching, I think)
-Eric
Quoted 12 lines · Eric Sandeen
libxfs/init.c retry: · line 160
Quoted 5 lines · Luis R. Rodriguez
libxfs/init.c +5
-0+if (ret ==1 ) { +fprintf (stderr, +_ ("%s: zoned disk detected, refer to dm-zoned-tools for how to use with XFS\n" ), + path); +exit (1 );Sorry for not sending this before V2, but is "dm-zoned-tools" established enough in the ecosystem at this point to embed it in help text of utilities like this?
Quoted 2 lines
(It's not in debian or in fedora, so that message might lead to some head-scratching, I think)
It *should*, I'll help up clean that project up a bit now with some meta crap which Debian police may want, but yeah not sure. You're call. Whatever you wish to print I'm fine with.
AFAICT dmzadm *should* be packaged at least. Long term perhaps lvm2 may re-implement it, but I can't see why folks should wait for such lofty vaporware.
Luis
Quoted 33 lines · Luis R. Rodriguez
Using raw zoned disks by filesystems requires special handling, only f2fs currently supports this. All other filesystems do not support dealing with zoned disks directly.
As such using raw zoned disks is not supported by XFS, to use them you need to use dm-zoned-tools, format them with dzadm, set the scheduler to deadline, and then setup a dmsetup with zoned type, and somehow set this up on every boot to live a semi-happy life for now.
Even if you use dmsetup on every boot, the zoned disk is still exposed, and a user may still think they have to run mkfs.xfs on it instead of the
/dev/mapper/disk, and then mount it by mistake.In either case you may seem to believe your disk works and only eventually end up with alignmet issues and perhaps lose you data. For instance:
[10869.959501] device-mapper: zoned reclaim: (sda): Align zone 865 wp 28349 to 30842 (wp+2493) blocks failed -5 [10870.014488] sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [10870.016137] sd 0:0:0:0: [sda] tag#0 Sense Key : Illegal Request [current] [10870.017696] sd 0:0:0:0: [sda] tag#0 Add. Sense: Unaligned write commandWe have to prevent these mistakes by avoiding mkfs.xfs use on zoned disks.
Note that this not enough yet, if users are on old AHCI controllers, the disks may not be detected as zoned. More work through udev may be required to detect this situation old old parent PCI IDs for zoned disks, and then prevent their use somehow.
If you are stuck on using XFS there a udev rule out there [0], this is far from perfect, and not fully what we want done upstream on Linux distributions long term but it should at least help developers for now enjoy their shiny big fat zoned disks with XFS.
Quoted 6 lines
This check should help avoid having folks shoot themselves in the foot for now with zoned disks. If you make the mistake to use mkfs.xfs on a zoned disk, you will now get:
# mkfs.xfs /dev/sda /dev/sda: zoned disk detected, refer to dm-zoned-tools for how to use with XFS
Shouldn't this code be put in libblkid() so it's available to all filesystem tools, not just XFS?
Cheers,
Dave.
Signature · 2 lines
Dave Chinner [email protected]