Commit ed17545d authored May 05, 2017 by Bob Peterson

GFS2: Allow glocks to be unlocked after withdraw



This bug fixes a regression introduced by patch 0d1c7ae9.

The intent of the patch was to stop promoting glocks after a
file system is withdrawn due to a variety of errors, because doing
so results in a BUG(). (You should be able to unmount after a
withdraw rather than having the kernel panic.)

Unfortunately, it also stopped demotions, so glocks could not be
unlocked after withdraw, which means the unmount would hang.

This patch allows function do_xmote to demote locks to an
unlocked state after a withdraw, but not promote them.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>

parent d552a2b9

fs/gfs2/glock.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -449,7 +449,8 @@ __acquires(&gl->gl_lockref.lock)
		unsigned int lck_flags = (unsigned int)(gh ? gh->gh_flags : 0);
		int ret;

		if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
		if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
		target != LM_ST_UNLOCKED)
		return;
		lck_flags &= (LM_FLAG_TRY \| LM_FLAG_TRY_1CB \| LM_FLAG_NOEXP \|
		LM_FLAG_PRIORITY);
		@@ -486,7 +487,8 @@ __acquires(&gl->gl_lockref.lock)
		}
		else if (ret) {
		pr_err("lm_lock ret %d\n", ret);
		GLOCK_BUG_ON(gl, 1);
		GLOCK_BUG_ON(gl, !test_bit(SDF_SHUTDOWN,
		&sdp->sd_flags));
		}
		} else { /* lock_nolock */
		finish_xmote(gl, target);

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