From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Tue, 4 Sep 2012 22:52:36 +0000 (-0700)
Subject: Switch KM_SLEEP to KM_PUSHPAGE
X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=commitdiff_plain;h=0ef0ff546eeab2f85690d59ee23fe30fa634dd38;p=zfs.git

Switch KM_SLEEP to KM_PUSHPAGE

This warning indicates the incorrect use of KM_SLEEP in a call
path which must use KM_PUSHPAGE to avoid deadlocking in direct
reclaim.  See commit b8d06fca089fae4680c3a552fc55c512bfb02202
for additional details.

  SPL: Fixing allocation for task txg_sync (6093) which
  used GFP flags 0x297bda7c with PF_NOFS set

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #917
---

diff --git a/include/sys/zfs_context.h b/include/sys/zfs_context.h
index 98b216f..8982c00 100644
--- a/include/sys/zfs_context.h
+++ b/include/sys/zfs_context.h
@@ -391,6 +391,7 @@ typedef struct taskq_ent {
 
 #define	TQ_SLEEP	KM_SLEEP	/* Can block for memory */
 #define	TQ_NOSLEEP	KM_NOSLEEP	/* cannot block for memory; may fail */
+#define	TQ_PUSHPAGE	KM_PUSHPAGE	/* Cannot perform I/O */
 #define	TQ_NOQUEUE	0x02		/* Do not enqueue if can't dispatch */
 #define	TQ_FRONT	0x08		/* Queue in front */
 
diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
index 755d057..7561434 100644
--- a/module/zfs/zfs_vnops.c
+++ b/module/zfs/zfs_vnops.c
@@ -868,7 +868,7 @@ iput_async(struct inode *ip, taskq_t *taskq)
 {
 	ASSERT(atomic_read(&ip->i_count) > 0);
 	if (atomic_read(&ip->i_count) == 1)
-		taskq_dispatch(taskq, (task_func_t *)iput, ip, TQ_SLEEP);
+		taskq_dispatch(taskq, (task_func_t *)iput, ip, TQ_PUSHPAGE);
 	else
 		iput(ip);
 }
@@ -934,7 +934,7 @@ zfs_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
 		return (ENOENT);
 	}
 
-	zgd = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
+	zgd = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_PUSHPAGE);
 	zgd->zgd_zilog = zsb->z_log;
 	zgd->zgd_private = zp;