X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Ftxg.c;fp=module%2Fzfs%2Ftxg.c;h=340c42ae84a395333d314507616ec4eb6deba848;hb=eec8164771bee067c3cd55ed0a16dadeeba276de;hp=00c1c7d26abe64dbf96d27ececd1be5d8f542817;hpb=7cb67b45f33fd7a61af24c675c7347eb5264b38c;p=zfs.git

diff --git a/module/zfs/txg.c b/module/zfs/txg.c
index 00c1c7d..340c42a 100644
--- a/module/zfs/txg.c
+++ b/module/zfs/txg.c
@@ -372,6 +372,19 @@ txg_sync_thread(dsl_pool_t *dp)
 	callb_cpr_t cpr;
 	uint64_t start, delta;
 
+#ifdef _KERNEL
+	/*
+	 * Disable the normal reclaim path for the txg_sync thread.  This
+	 * ensures the thread will never enter dmu_tx_assign() which can
+	 * otherwise occur due to direct reclaim.  If this is allowed to
+	 * happen the system can deadlock.  Direct reclaim call path:
+	 *
+	 *   ->shrink_icache_memory->prune_icache->dispose_list->
+	 *   clear_inode->zpl_clear_inode->zfs_inactive->dmu_tx_assign
+	 */
+	current->flags |= PF_MEMALLOC;
+#endif /* _KERNEL */
+
 	txg_thread_enter(tx, &cpr);
 
 	start = delta = 0;