On Wed, May 22, 2019 at 11:03:17AM +0200, Jan Kara wrote: > ext4_break_layouts() may fail e.g. due to a signal being delivered. > Thus we need to handle its failure gracefully and not by taking the > filesystem down. Currently ext4_break_layouts() failure is rare but it > may become more common once RDMA uses layout leases for handling > long-term page pins for DAX mappings. > > To handle the failure we need to move ext4_break_layouts() earlier > during setattr handling before we do hard to undo changes such as > modifying inode size. To be able to do that we also have to move some > other checks which are better done without holding i_mmap_sem earlier. > > Reported-and-tested-by: Ira Weiny <ira.weiny@xxxxxxxxx> > Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx> > Signed-off-by: Jan Kara <jack@xxxxxxx> When doing some final testing before sending a pull request to Linus, I found a regression. After bisecting, this patch fails reliably under gce-xfstests: TESTRUNID: tytso-20190524230226 KERNEL: kernel 5.1.0-rc3-xfstests-00039-g079f9927c7bf #1016 SMP Fri May 24 23:00:47 EDT 2019 x86_64 CMDLINE: -c 4k generic/092 CPUS: 2 MEM: 7680 ext4/4k: 1 tests, 1 failures, 2 seconds generic/092 Failed 1s Totals: 1 tests, 0 skipped, 1 failures, 0 errors, 1s FSTESTPRJ: gce-xfstests FSTESTVER: fio fio-3.2 (Fri, 3 Nov 2017 15:23:49 -0600) FSTESTVER: quota 62661bd (Tue, 2 Apr 2019 17:04:37 +0200) FSTESTVER: xfsprogs v5.0.0 (Fri, 3 May 2019 12:14:36 -0500) FSTESTVER: xfstests-bld 9582562 (Sun, 12 May 2019 00:38:51 -0400) FSTESTVER: xfstests linux-v3.8-2390-g64233614 (Thu, 16 May 2019 00:12:52 -0400) FSTESTCFG: 4k FSTESTSET: generic/092 FSTESTOPT: aex GCE ID: 343197219467628221 generic/092 0s ... [23:05:07] [23:05:08]- output mismatch (see /results/ext4/results-4k/generic/092 .out.bad) % diff -u /tmp/results-tytso-20190524230226/ext4/results-4k/generic/092.out.bad /usr/projects/xfstests-bld/build-64/xfstests-dev/tests/generic/092.out --- /tmp/results-tytso-20190524230226/ext4/results-4k/generic/092.out.bad 2019-05-24 23:05:08.000000000 -0400 +++ /usr/projects/xfstests-bld/build-64/xfstests-dev/tests/generic/092.out 2018-02-13 23:37:20.330097382 -0500 @@ -2,6 +2,5 @@ wrote 5242880/5242880 bytes at offset 0 XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) 0: [0..10239]: data -1: [10240..20479]: unwritten 0: [0..10239]: data 1: [10240..20479]: unwritten Dropping this patch makes the test failure go away. So I'm going to drop it for now. Jan, can you take a look? Thanks!! - Ted
