[Cluster-devel] [PATCH 0/4] gfs2: logd cleanups on for-next

[Cluster-devel] [PATCH 0/4] gfs2: logd cleanups on for-next

[Andreas Gruenbacher]

The following four patches related to gfs2's logd daemon are currently
queued up on our for-next branch, to be submitted upstream in the
upcoming merge window.

https://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2.git/log/?h=for-next

Thanks,
Andreas

Andreas Gruenbacher (4):
  gfs2: Switch to wait_event in gfs2_logd
  gfs2: low-memory forced flush fixes
  gfs2: Fix logd wakeup on I/O error
  gfs2: journal flush threshold fixes and cleanup

 fs/gfs2/aops.c |  4 +++-
 fs/gfs2/log.c  | 60 ++++++++++++++++++++++----------------------------
 2 files changed, 29 insertions(+), 35 deletions(-)

-- 
2.40.1

[Cluster-devel] [PATCH 1/4] gfs2: Switch to wait_event in gfs2_logd

[Andreas Gruenbacher]

In gfs2_logd(), switch from an open-coded wait loop to
wait_event_interruptible_timeout().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/gfs2/log.c | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index aa568796207c..d3da259820e3 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -1301,7 +1301,6 @@ int gfs2_logd(void *data)
 {
 	struct gfs2_sbd *sdp = data;
 	unsigned long t = 1;
-	DEFINE_WAIT(wait);
 
 	while (!kthread_should_stop()) {
 
@@ -1338,17 +1337,11 @@ int gfs2_logd(void *data)
 
 		try_to_freeze();
 
-		do {
-			prepare_to_wait(&sdp->sd_logd_waitq, &wait,
-					TASK_INTERRUPTIBLE);
-			if (!gfs2_ail_flush_reqd(sdp) &&
-			    !gfs2_jrnl_flush_reqd(sdp) &&
-			    !kthread_should_stop())
-				t = schedule_timeout(t);
-		} while(t && !gfs2_ail_flush_reqd(sdp) &&
-			!gfs2_jrnl_flush_reqd(sdp) &&
-			!kthread_should_stop());
-		finish_wait(&sdp->sd_logd_waitq, &wait);
+		t = wait_event_interruptible_timeout(sdp->sd_logd_waitq,
+				gfs2_ail_flush_reqd(sdp) ||
+				gfs2_jrnl_flush_reqd(sdp) ||
+				kthread_should_stop(),
+				t);
 	}
 
 	return 0;
-- 
2.40.1

[Cluster-devel] [PATCH 2/4] gfs2: low-memory forced flush fixes

[Andreas Gruenbacher]

Function gfs2_ail_flush_reqd checks the SDF_FORCE_AIL_FLUSH flag to
determine if an AIL flush should be forced in low-memory situations.
However, it also immediately clears the flag, and when called repeatedly
as in function gfs2_logd, the flag will be lost.  Fix that by pulling
the SDF_FORCE_AIL_FLUSH flag check out of gfs2_ail_flush_reqd.

In addition, in gfs2_writepages, logd needs to be woken up after setting
the SDF_FORCE_AIL_FLUSH flag.

Fixes: b066a4eebd4f ("gfs2: forcibly flush ail to relieve memory pressure")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/gfs2/aops.c | 4 +++-
 fs/gfs2/log.c  | 8 ++++----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 5f02542370c4..d15a10a18962 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -189,8 +189,10 @@ static int gfs2_writepages(struct address_space *mapping,
 	 * pages held in the ail that it can't find.
 	 */
 	ret = iomap_writepages(mapping, wbc, &wpc, &gfs2_writeback_ops);
-	if (ret == 0)
+	if (ret == 0) {
 		set_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
+		wake_up(&sdp->sd_logd_waitq);
+	}
 	return ret;
 }
 
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index d3da259820e3..aaca22f2aa2d 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -1282,9 +1282,6 @@ static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
 {
 	unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
 
-	if (test_and_clear_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags))
-		return 1;
-
 	return used_blocks + atomic_read(&sdp->sd_log_blks_needed) >=
 		atomic_read(&sdp->sd_log_thresh2);
 }
@@ -1325,7 +1322,9 @@ int gfs2_logd(void *data)
 						  GFS2_LFC_LOGD_JFLUSH_REQD);
 		}
 
-		if (gfs2_ail_flush_reqd(sdp)) {
+		if (test_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags) ||
+		    gfs2_ail_flush_reqd(sdp)) {
+			clear_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags);
 			gfs2_ail1_start(sdp);
 			gfs2_ail1_wait(sdp);
 			gfs2_ail1_empty(sdp, 0);
@@ -1338,6 +1337,7 @@ int gfs2_logd(void *data)
 		try_to_freeze();
 
 		t = wait_event_interruptible_timeout(sdp->sd_logd_waitq,
+				test_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags) ||
 				gfs2_ail_flush_reqd(sdp) ||
 				gfs2_jrnl_flush_reqd(sdp) ||
 				kthread_should_stop(),
-- 
2.40.1

[Cluster-devel] [PATCH 3/4] gfs2: Fix logd wakeup on I/O error

[Andreas Gruenbacher]

When quotad detects an I/O error, it sets sd_log_error and then it wakes
up logd to withdraw the filesystem.  However, logd doesn't wake up when
sd_log_error is set.  Fix that.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/gfs2/log.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index aaca22f2aa2d..abe4397dc59b 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -1340,6 +1340,7 @@ int gfs2_logd(void *data)
 				test_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags) ||
 				gfs2_ail_flush_reqd(sdp) ||
 				gfs2_jrnl_flush_reqd(sdp) ||
+				sdp->sd_log_error ||
 				kthread_should_stop(),
 				t);
 	}
-- 
2.40.1

[Cluster-devel] [PATCH 4/4] gfs2: journal flush threshold fixes and cleanup

[Andreas Gruenbacher]

Commit f07b35202148 ("GFS2: Made logd daemon take into account log
demand") changed gfs2_ail_flush_reqd() and gfs2_jrnl_flush_reqd() to
take sd_log_blks_needed into account, but the checks in
gfs2_log_commit() were not updated correspondingly.

Once that is fixed, gfs2_jrnl_flush_reqd() and gfs2_ail_flush_reqd() can
be used in gfs2_log_commit().  Make those two helpers available to
gfs2_log_commit() by defining them above gfs2_log_commit().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/gfs2/log.c | 34 ++++++++++++++++------------------
 1 file changed, 16 insertions(+), 18 deletions(-)

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index abe4397dc59b..addf4ce0bedd 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -1227,6 +1227,21 @@ static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 	gfs2_log_unlock(sdp);
 }
 
+static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
+{
+	return atomic_read(&sdp->sd_log_pinned) +
+	       atomic_read(&sdp->sd_log_blks_needed) >=
+	       atomic_read(&sdp->sd_log_thresh1);
+}
+
+static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
+{
+	return sdp->sd_jdesc->jd_blocks -
+	       atomic_read(&sdp->sd_log_blks_free) +
+	       atomic_read(&sdp->sd_log_blks_needed) >=
+	       atomic_read(&sdp->sd_log_thresh2);
+}
+
 /**
  * gfs2_log_commit - Commit a transaction to the log
  * @sdp: the filesystem
@@ -1246,9 +1261,7 @@ void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 {
 	log_refund(sdp, tr);
 
-	if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
-	    ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
-	    atomic_read(&sdp->sd_log_thresh2)))
+	if (gfs2_ail_flush_reqd(sdp) || gfs2_jrnl_flush_reqd(sdp))
 		wake_up(&sdp->sd_logd_waitq);
 }
 
@@ -1271,21 +1284,6 @@ static void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 	gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
 }
 
-static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
-{
-	return (atomic_read(&sdp->sd_log_pinned) +
-		atomic_read(&sdp->sd_log_blks_needed) >=
-		atomic_read(&sdp->sd_log_thresh1));
-}
-
-static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
-{
-	unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
-
-	return used_blocks + atomic_read(&sdp->sd_log_blks_needed) >=
-		atomic_read(&sdp->sd_log_thresh2);
-}
-
 /**
  * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
  * @data: Pointer to GFS2 superblock
-- 
2.40.1