Commit 2cbd8064 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher
Browse files

gfs2: Fix freeze consistency check in gfs2_trans_add_meta 



Function gfs2_trans_add_meta() checks for the SDF_FROZEN flag to make
sure that no buffers are added to a transaction while the filesystem is
frozen.  With the recent freeze/thaw rework, the SDF_FROZEN flag is
cleared after thaw_super() is called, which is sufficient for
serializing freeze/thaw.

However, other filesystem operations started after thaw_super() may now
be calling gfs2_trans_add_meta() before the SDF_FROZEN flag is cleared,
which will trigger the SDF_FROZEN check in gfs2_trans_add_meta().  Fix
that by checking the s_writers.frozen state instead.

In addition, make sure not to call gfs2_assert_withdraw() with the
sd_log_lock spin lock held.  Check for a withdrawn filesystem before
checking for a frozen filesystem, and don't pin/add buffers to the
current transaction in case of a failure in either case.

Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
parent 94c76955

fs/gfs2/trans.c

+10 −4
Original line number Diff line number Diff line
@@ -230,9 +230,11 @@ void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh) 
{



	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;

	struct super_block *sb = sdp->sd_vfs;

	struct gfs2_bufdata *bd;

	struct gfs2_meta_header *mh;

	struct gfs2_trans *tr = current->journal_info;

	bool withdraw = false;



	lock_buffer(bh);

	if (buffer_pinned(bh)) {
@@ -266,13 +268,15 @@ void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh) 
		       (unsigned long long)bd->bd_bh->b_blocknr);

		BUG();

	}

	if (unlikely(test_bit(SDF_FROZEN, &sdp->sd_flags))) {

		fs_info(sdp, "GFS2:adding buf while frozen\n");

		gfs2_assert_withdraw(sdp, 0);

	}

	if (unlikely(gfs2_withdrawn(sdp))) {

		fs_info(sdp, "GFS2:adding buf while withdrawn! 0x%llx\n",

			(unsigned long long)bd->bd_bh->b_blocknr);

		goto out_unlock;

	}

	if (unlikely(sb->s_writers.frozen == SB_FREEZE_COMPLETE)) {

		fs_info(sdp, "GFS2:adding buf while frozen\n");

		withdraw = true;

		goto out_unlock;

	}

	gfs2_pin(sdp, bd->bd_bh);

	mh->__pad0 = cpu_to_be64(0);
@@ -281,6 +285,8 @@ void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh) 
	tr->tr_num_buf_new++;

out_unlock:

	gfs2_log_unlock(sdp);

	if (withdraw)

		gfs2_assert_withdraw(sdp, 0);

out:

	unlock_buffer(bh);

}