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From 16e6281b6b22b0178eab95c6a82502d7b10f67b8 Mon Sep 17 00:00:00 2001 |
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From: Alexander Aring <aahringo@redhat.com> |
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Date: Sun, 22 Nov 2020 18:10:24 -0500 |
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Subject: [PATCH 108/150] gfs2: Fix deadlock dumping resource group glocks |
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Commit 0e539ca1bbbe ("gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump") |
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introduced additional locking in gfs2_rgrp_go_dump, which is also used for |
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dumping resource group glocks via debugfs. However, on that code path, the |
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glock spin lock is already taken in dump_glock, and taking it again in |
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gfs2_glock2rgrp leads to deadlock. This can be reproduced with: |
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|
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$ mkfs.gfs2 -O -p lock_nolock /dev/FOO |
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$ mount /dev/FOO /mnt/foo |
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$ touch /mnt/foo/bar |
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$ cat /sys/kernel/debug/gfs2/FOO/glocks |
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|
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Fix that by not taking the glock spin lock inside the go_dump callback. |
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|
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Fixes: 0e539ca1bbbe ("gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump") |
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Signed-off-by: Alexander Aring <aahringo@redhat.com> |
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Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> |
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--- |
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fs/gfs2/glops.c | 2 +- |
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1 file changed, 1 insertion(+), 1 deletion(-) |
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|
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diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c |
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index 67f2921ae8d4..6cedeefb7b3f 100644 |
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--- a/fs/gfs2/glops.c |
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+++ b/fs/gfs2/glops.c |
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@@ -245,7 +245,7 @@ static void rgrp_go_inval(struct gfs2_glock *gl, int flags) |
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static void gfs2_rgrp_go_dump(struct seq_file *seq, struct gfs2_glock *gl, |
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const char *fs_id_buf) |
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{ |
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- struct gfs2_rgrpd *rgd = gfs2_glock2rgrp(gl); |
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+ struct gfs2_rgrpd *rgd = gl->gl_object; |
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|
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if (rgd) |
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gfs2_rgrp_dump(seq, rgd, fs_id_buf); |
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-- |
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2.29.2 |
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