| Message ID | 20200219030851.2678-1-surajjs@amazon.com |
|---|---|
| Headers | show |
| Series | ext4: Fix potential races when performing online resizing | expand |
Hi Suraj, All of the patches to fix BZ 206443 are now on the ext4 git tree: https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/log/?h=dev I'm currently giving them a full regression test set using xfstests. Could you run your tests to make sure it looks good for you? I'm hoping to issue a pull request to Linus in time for 5.6-rc3 by this weekend. Also, if you can figure out a way to package up the repro as an xfstests test case, that would be really excellent. I think the challenge is that some of them took a *huge* amount of pounding before they repro'ed, correct? I wasn't actually able to trigger the repro using kvm, but I was only using a 2 CPU configuration. Thanks, - Ted
On Thu, 2020-02-20 at 01:14 -0500, Theodore Y. Ts'o wrote: > Hi Suraj, > > All of the patches to fix BZ 206443 are now on the ext4 git tree: > > https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/log/?h=dev > > I'm currently giving them a full regression test set using xfstests. > Could you run your tests to make sure it looks good for you? Hi, Have run my repo case for 6 hours without issue. Previously this reproduced 100% of the time within <30 mins. > > I'm hoping to issue a pull request to Linus in time for 5.6-rc3 by > this weekend. > > Also, if you can figure out a way to package up the repro as an > xfstests test case, that would be really excellent. I think the > challenge is that some of them took a *huge* amount of pounding > before > they repro'ed, correct? I wasn't actually able to trigger the repro > using kvm, but I was only using a 2 CPU configuration. I will look into this. Thanks, Suraj > > Thanks, > > - Ted >
This patch series fixes 2 additional races between array resizing and array element access when performing online resizing of the arrays s_group_info and s_flex_groups. These patches apply on top of the patch: [PATCH RFC] ext4: fix potential race between online resizing and write operations The macro sbi_array_rcu_deref() is introduced for simplicity but can be removed if undesired. Tested by performing the following: truncate -s 100G /tmp/foo sudo bash -c 'while true; do dd if=/dev/zero of=/mnt/xxx bs=1M count=1; sync; \ rm /mnt/xxx; done' & while true; do mkfs.ext4 -b 1024 -E resize=26213883 /tmp/foo 2096635 -F; \ sudo mount -o loop /tmp/foo /mnt; sudo resize2fs /dev/loop0 26213883; \ sudo umount /mnt; done Suraj Jitindar Singh (3): ext4: introduce macro sbi_array_rcu_deref() to access rcu protected fields ext4: fix potential race between s_group_info online resizing and access ext4: fix potential race between s_flex_groups online resizing and access fs/ext4/balloc.c | 11 +++++----- fs/ext4/ext4.h | 25 +++++++++++++++++---- fs/ext4/ialloc.c | 21 +++++++++++------- fs/ext4/mballoc.c | 19 ++++++++++------ fs/ext4/resize.c | 4 ++-- fs/ext4/super.c | 56 ++++++++++++++++++++++++++++++++--------------- 6 files changed, 91 insertions(+), 45 deletions(-)