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| author | Alexander Aring <aahringo@redhat.com> | 2020-11-23 02:10:24 +0300 |
|---|---|---|
| committer | Andreas Gruenbacher <agruenba@redhat.com> | 2020-11-25 01:45:58 +0300 |
| commit | 16e6281b6b22b0178eab95c6a82502d7b10f67b8 (patch) | |
| tree | 48ca6ba8ee370a7c40b7a5e99d84c394341d39a0 /fs/gfs2/glops.c | |
| parent | 418baf2c28f3473039f2f7377760bd8f6897ae18 (diff) | |
| download | linux-16e6281b6b22b0178eab95c6a82502d7b10f67b8.tar.xz | |
gfs2: Fix deadlock dumping resource group glocks
Commit 0e539ca1bbbe ("gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump")
introduced additional locking in gfs2_rgrp_go_dump, which is also used for
dumping resource group glocks via debugfs. However, on that code path, the
glock spin lock is already taken in dump_glock, and taking it again in
gfs2_glock2rgrp leads to deadlock. This can be reproduced with:
$ mkfs.gfs2 -O -p lock_nolock /dev/FOO
$ mount /dev/FOO /mnt/foo
$ touch /mnt/foo/bar
$ cat /sys/kernel/debug/gfs2/FOO/glocks
Fix that by not taking the glock spin lock inside the go_dump callback.
Fixes: 0e539ca1bbbe ("gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Diffstat (limited to 'fs/gfs2/glops.c')
| -rw-r--r-- | fs/gfs2/glops.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c index 67f2921ae8d4..6cedeefb7b3f 100644 --- a/fs/gfs2/glops.c +++ b/fs/gfs2/glops.c @@ -245,7 +245,7 @@ static void rgrp_go_inval(struct gfs2_glock *gl, int flags) static void gfs2_rgrp_go_dump(struct seq_file *seq, struct gfs2_glock *gl, const char *fs_id_buf) { - struct gfs2_rgrpd *rgd = gfs2_glock2rgrp(gl); + struct gfs2_rgrpd *rgd = gl->gl_object; if (rgd) gfs2_rgrp_dump(seq, rgd, fs_id_buf); |