Skip to content

L
linux
Switch branch/tag
  1. 08 Feb, 2021 1 commit
  3. 05 Feb, 2021 2 commits
    • Bob Peterson's avatar
      gfs2: Don't skip dlm unlock if glock has an lvb · 78178ca8
      Bob Peterson authored 
      Patch fb6791d1 was designed to allow gfs2 to unmount quicker by
skipping the step where it tells dlm to unlock glocks in EX with lvbs.
This was done because when gfs2 unmounts a file system, it destroys the
dlm lockspace shortly after it destroys the glocks so it doesn't need to
unlock them all: the unlock is implied when the lockspace is destroyed
by dlm.

However, that patch introduced a use-after-free in dlm: as part of its
normal dlm_recoverd process, it can call ls_recovery to recover dead
locks. In so doing, it can call recover_rsbs which calls recover_lvb for
any mastered rsbs. Func recover_lvb runs through the list of lkbs queued
to the given rsb (if the glock is cached but unlocked, it will still be
queued to the lkb, but in NL--Unlocked--mode) and if it has an lvb,
copies it to the rsb, thus trying to preserve the lkb. However, when
gfs2 skips the dlm unlock step, it frees the glock and its lvb, which
means dlm's function recover_lvb references the now freed lvb pointer,
copying the freed lvb memory to the rsb.

This patch changes the check in gdlm_put_lock so that it calls
dlm_unlock for all glocks that contain an lvb pointer.

Fixes: fb6791d1 ("GFS2: skip dlm_unlock calls in unmount")
Cc: stable@vger.kernel.org # v3.8+
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
      78178ca8
    • Andreas Gruenbacher's avatar
      gfs2: Lock imbalance on error path in gfs2_recover_one · 834ec3e1
      Andreas Gruenbacher authored 
      In gfs2_recover_one, fix a sd_log_flush_lock imbalance when a recovery
pass fails.

Fixes: c9ebc4b7 ("gfs2: allow journal replay to hold sd_log_flush_lock")
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
      834ec3e1
  5. 25 Jan, 2021 4 commits
  7. 22 Jan, 2021 1 commit
  9. 31 Dec, 2020 1 commit
  11. 22 Dec, 2020 2 commits
    • Bob Peterson's avatar
      gfs2: move freeze glock outside the make_fs_rw and _ro functions · 96b1454f
      Bob Peterson authored 
      Before this patch, sister functions gfs2_make_fs_rw and gfs2_make_fs_ro locked
(held) the freeze glock by calling gfs2_freeze_lock and gfs2_freeze_unlock.
The problem is, not all the callers of gfs2_make_fs_ro should be doing this.
The three callers of gfs2_make_fs_ro are: remount (gfs2_reconfigure),
signal_our_withdraw, and unmount (gfs2_put_super). But when unmounting the
file system we can get into the following circular lock dependency:

deactivate_super
   down_write(&s->s_umount); <-------------------------------------- s_umount
   deactivate_locked_super
      gfs2_kill_sb
         kill_block_super
            generic_shutdown_super
               gfs2_put_super
                  gfs2_make_fs_ro
                     gfs2_glock_nq_init sd_freeze_gl
                        freeze_go_sync
                           if (freeze glock in SH)
                              freeze_super (vfs)
                                 down_write(&sb->s_umount); <------- s_umount

This patch moves the hold of the freeze glock outside the two sister rw/ro
functions to their callers, but it doesn't request the glock from
gfs2_put_super, thus eliminating the circular dependency.
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
      96b1454f
    • Bob Peterson's avatar
      gfs2: Add common helper for holding and releasing the freeze glock · c77b52c0
      Bob Peterson authored 
      Many places in the gfs2 code queued and dequeued the freeze glock.
Almost all of them acquire it in SHARED mode, and need to specify the
same LM_FLAG_NOEXP and GL_EXACT flags.

This patch adds common helper functions gfs2_freeze_lock and gfs2_freeze_unlock
to make the code more readable, and to prepare for the next patch.
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
      c77b52c0
  13. 20 Dec, 2020 2 commits
  15. 19 Dec, 2020 27 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7