md/raid: only permit hot-add of compatible integrity profiles
It is not safe for an integrity profile to be changed while i/o is
in-flight in the queue. Prevent adding new disks or otherwise online
spares to an array if the device has an incompatible integrity profile.
The original change to the blk_integrity_unregister implementation in
md, commmit c7bfced9a671 "md: suspend i/o during runtime
blk_integrity_unregister" introduced an immediate hang regression.
This policy of disallowing changes the integrity profile once one has
been established is shared with DM.
Here is an abbreviated log from a test run that:
1/ Creates a degraded raid1 with an integrity-enabled device (pmem0s) [ 59.076127]
2/ Tries to add an integrity-disabled device (pmem1m) [ 90.489209]
3/ Retries with an integrity-enabled device (pmem1s) [ 205.671277]
[ 59.076127] md/raid1:md0: active with 1 out of 2 mirrors
[ 59.078302] md: data integrity enabled on md0
[..]
[ 90.489209] md0: incompatible integrity profile for pmem1m
[..]
[ 205.671277] md: super_written gets error=-5
[ 205.677386] md/raid1:md0: Disk failure on pmem1m, disabling device.
[ 205.677386] md/raid1:md0: Operation continuing on 1 devices.
[ 205.683037] RAID1 conf printout:
[ 205.684699] --- wd:1 rd:2
[ 205.685972] disk 0, wo:0, o:1, dev:pmem0s
[ 205.687562] disk 1, wo:1, o:1, dev:pmem1s
[ 205.691717] md: recovery of RAID array md0
Fixes: c7bfced9a671 ("md: suspend i/o during runtime blk_integrity_unregister")
Cc: <stable@vger.kernel.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Reported-by: NeilBrown <neilb@suse.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.com>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8753dee..2cf0e1c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2010,28 +2010,32 @@
}
EXPORT_SYMBOL(md_integrity_register);
-/* Disable data integrity if non-capable/non-matching disk is being added */
-void md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
+/*
+ * Attempt to add an rdev, but only if it is consistent with the current
+ * integrity profile
+ */
+int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
{
struct blk_integrity *bi_rdev;
struct blk_integrity *bi_mddev;
+ char name[BDEVNAME_SIZE];
if (!mddev->gendisk)
- return;
+ return 0;
bi_rdev = bdev_get_integrity(rdev->bdev);
bi_mddev = blk_get_integrity(mddev->gendisk);
if (!bi_mddev) /* nothing to do */
- return;
- if (rdev->raid_disk < 0) /* skip spares */
- return;
- if (bi_rdev && blk_integrity_compare(mddev->gendisk,
- rdev->bdev->bd_disk) >= 0)
- return;
- WARN_ON_ONCE(!mddev->suspended);
- printk(KERN_NOTICE "disabling data integrity on %s\n", mdname(mddev));
- blk_integrity_unregister(mddev->gendisk);
+ return 0;
+
+ if (blk_integrity_compare(mddev->gendisk, rdev->bdev->bd_disk) != 0) {
+ printk(KERN_NOTICE "%s: incompatible integrity profile for %s\n",
+ mdname(mddev), bdevname(rdev->bdev, name));
+ return -ENXIO;
+ }
+
+ return 0;
}
EXPORT_SYMBOL(md_integrity_add_rdev);