[Devel] [PATCH RHEL7 COMMIT] ploop: warning on "disk full" condition

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-123.1.2-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-123.1.2.vz7.5.1
------>
commit b6eb7575242d5e266d231ed53a4f7e03e47b2a68
Author: Andrey Smetanin <asmetanin at virtuozzo.com>
Date:   Tue May 19 08:27:10 2015 +0400

    ploop: warning on "disk full" condition
    
    People complain that it's not always obvious why an app in CT gets
    -ENOSPC while there remains some space on host filesystem.
    
    The patch adds time ratelimited printk about "disk full" condition.
    Maximal rate is 1 per hour.
    
    https://bugzilla.openvz.org/show_bug.cgi?id=3045
    
    Signed-off-by: Maxim Patlasov <MPatlasov at parallels.com>
---
 drivers/block/ploop/dev.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
index 9aaab4a..ab99724 100644
--- a/drivers/block/ploop/dev.c
+++ b/drivers/block/ploop/dev.c
@@ -3533,8 +3533,18 @@ static int ploop_bd_full(struct backing_dev_info *bdi, long long nr, int root)
 
 		current->journal_info = NULL;
 		ret = sb->s_op->statfs(F_DENTRY(file), &buf);
-		if (ret || buf.f_bfree * buf.f_bsize < reserved + nr)
+		if (ret || buf.f_bfree * buf.f_bsize < reserved + nr) {
+			static unsigned long full_warn_time;
+
+			if (printk_timed_ratelimit(&full_warn_time, 60*60*HZ))
+				printk(KERN_WARNING
+				       "ploop%d: host disk is almost full "
+				       "(%llu < %llu); CT sees -ENOSPC !\n",
+				       plo->index, buf.f_bfree * buf.f_bsize,
+				       reserved + nr);
+
 			rc = 1;
+		}
 
 		fput(file);
 		current->journal_info = jctx;