Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.12 110/161] gfs2: fix scheduling while atomic bug in glocks | Date | Tue, 8 Jun 2021 20:27:20 +0200 |
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From: Bob Peterson <rpeterso@redhat.com>
commit 20265d9a67e40eafd39a8884658ca2e36f05985d upstream.
Before this patch, in the unlikely event that gfs2_glock_dq encountered a withdraw, it would do a wait_on_bit to wait for its journal to be recovered, but it never released the glock's spin_lock, which caused a scheduling-while-atomic error.
This patch unlocks the lockref spin_lock before waiting for recovery.
Fixes: 601ef0d52e96 ("gfs2: Force withdraw to replay journals and wait for it to finish") Cc: stable@vger.kernel.org # v5.7+ Reported-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/gfs2/glock.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -1465,9 +1465,11 @@ void gfs2_glock_dq(struct gfs2_holder *g glock_blocked_by_withdraw(gl) && gh->gh_gl != sdp->sd_jinode_gl) { sdp->sd_glock_dqs_held++; + spin_unlock(&gl->gl_lockref.lock); might_sleep(); wait_on_bit(&sdp->sd_flags, SDF_WITHDRAW_RECOVERY, TASK_UNINTERRUPTIBLE); + spin_lock(&gl->gl_lockref.lock); } if (gh->gh_flags & GL_NOCACHE) handle_callback(gl, LM_ST_UNLOCKED, 0, false);
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