On Wed, Nov 07, 2018 at 07:09:42AM +0200, Amir Goldstein wrote:
On Mon, Nov 5, 2018 at 7:57 PM Amir Goldstein amir73il@gmail.com wrote:
On Sat, Nov 3, 2018 at 7:15 PM Amir Goldstein amir73il@gmail.com wrote:
From: Brian Foster bfoster@redhat.com
The truncate transaction does not ever modify the inode btree, but includes an associated log reservation. Update xfs_calc_itruncate_reservation() to remove the reservation associated with inobt updates.
[Amir: This commit was merged for kernel v4.16 and a twin commit was merged for xfsprogs v4.16. As a result, a small xfs filesystem formatted with features -m rmapbt=1,reflink=1 using mkfs.xfs version >= v4.16 cannot be mounted with kernel < v4.16.
For example, xfstests generic/17{1,2,3} format a small fs and when trying to mount it, they fail with an assert on this very demonic line:XFS (vdc): Log size 3075 blocks too small, minimum size is 3717 blocks XFS (vdc): AAIEEE! Log failed size checks. Abort! XFS: Assertion failed: 0, file: src/linux/fs/xfs/xfs_log.c, line: 666
The simple solution for stable kernels is to apply this patch, because mkfs.xfs v4.16 is already in the wild, so we have to assume that xfs filesystems with a "too small" log exist. Regardless, xfsprogs maintainers should also consider reverting the twin patch to stop creating those filesystems for the sake of users with unpatched kernels.]Signed-off-by: Brian Foster bfoster@redhat.com Reviewed-by: Dave Chinner dchinner@redhat.com Reviewed-by: Darrick J. Wong darrick.wong@oracle.com Signed-off-by: Darrick J. Wong darrick.wong@oracle.com Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Amir Goldstein amir73il@gmail.com
Darrick/Dave,
It took me a while to figure out what was going on with my test systems when small test partitions (10G) stopped working with older kernels.
Please bless this change for stable and consider the remedie for mkfs.xfs I verified that patch cleanly applies to stable kernels 4.14.y and 4.9.y and that I can mount a filsystem created with new mkfs.xfs.
I am now running quick tests on stable 4.14.y with configs 4k, 1k, reflink,reflink+overlay to verify no regressions from this patch.
FYI no regressions detected.
Thoughts?
Maybe you'd want to chalk it up to reflink/rmapbt being Experimental before kernel 4.16? so the change in "minimum log size" is an on-disk format change prior to removing the Experimental label??
TBH nobody should be using reflink/rmap on 4.14 kernels, ever. :D
That said... does it change the minimum log size for (finobt, !reflink, !rmap) filesystems? That might be a bigger worry. I /think/ the transaction reservation change is fine, though I defer to Amir on testing... :)
--D
Thanks, Amir.