Commit fe2c8d05 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher
Browse files

gfs2: add some missing log locking 



Function gfs2_logd() calls the log flushing functions gfs2_ail1_start(),
gfs2_ail1_wait(), and gfs2_ail1_empty() without holding sdp->sd_log_flush_lock,
but these functions require exclusion against concurrent transactions.

To fix that, add a non-locking __gfs2_log_flush() function.  Then, in
gfs2_logd(), take sdp->sd_log_flush_lock before calling the above mentioned log
flushing functions and __gfs2_log_flush().

Fixes: 5e4c7632 ("gfs2: Issue revokes more intelligently")
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
parent f4e4c4e6

fs/gfs2/log.c

+20 −8
Original line number Diff line number Diff line
@@ -1053,14 +1053,15 @@ void gfs2_remove_from_journal(struct buffer_head *bh, int meta) 
}



/**

 * gfs2_log_flush - flush incore transaction(s)

 * __gfs2_log_flush - flush incore transaction(s)

 * @sdp: The filesystem

 * @gl: The glock structure to flush.  If NULL, flush the whole incore log

 * @flags: The log header flags: GFS2_LOG_HEAD_FLUSH_* and debug flags

 *

 */



void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags)

static void __gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl,

			     u32 flags)

{

	struct gfs2_trans *tr = NULL;

	unsigned int reserved_blocks = 0, used_blocks = 0;
@@ -1068,7 +1069,6 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) 
	unsigned int first_log_head;

	unsigned int reserved_revokes = 0;



	down_write(&sdp->sd_log_flush_lock);

	trace_gfs2_log_flush(sdp, 1, flags);



repeat:
@@ -1180,7 +1180,6 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) 
		gfs2_assert_withdraw(sdp, used_blocks < reserved_blocks);

		gfs2_log_release(sdp, reserved_blocks - used_blocks);

	}

	up_write(&sdp->sd_log_flush_lock);

	gfs2_trans_free(sdp, tr);

	trace_gfs2_log_flush(sdp, 0, flags);

	return;
@@ -1201,6 +1200,13 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) 
	goto out_end;

}



void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags)

{

	down_write(&sdp->sd_log_flush_lock);

	__gfs2_log_flush(sdp, gl, flags);

	up_write(&sdp->sd_log_flush_lock);

}



/**

 * gfs2_merge_trans - Merge a new transaction into a cached transaction

 * @sdp: the filesystem
@@ -1332,19 +1338,25 @@ int gfs2_logd(void *data) 
			break;



		if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {

			down_write(&sdp->sd_log_flush_lock);

			gfs2_ail1_empty(sdp, 0);

			gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |

			__gfs2_log_flush(sdp, NULL,

					 GFS2_LOG_HEAD_FLUSH_NORMAL |

					 GFS2_LFC_LOGD_JFLUSH_REQD);

			up_write(&sdp->sd_log_flush_lock);

		}



		if (test_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags) ||

		    gfs2_ail_flush_reqd(sdp)) {

			clear_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);

			down_write(&sdp->sd_log_flush_lock);

			gfs2_ail1_start(sdp);

			gfs2_ail1_wait(sdp);

			gfs2_ail1_empty(sdp, 0);

			gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |

			__gfs2_log_flush(sdp, NULL,

					 GFS2_LOG_HEAD_FLUSH_NORMAL |

					 GFS2_LFC_LOGD_AIL_FLUSH_REQD);

			up_write(&sdp->sd_log_flush_lock);

		}



		t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;