2 files changed, 8 insertions, 1 deletions

diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index 97c4b3284329..b716d33912d8 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -90,6 +90,10 @@ will itself start writeback.
 If dirty_bytes is written, dirty_ratio becomes a function of its value
 (dirty_bytes / the amount of dirtyable system memory).
 
+Note: the minimum value allowed for dirty_bytes is two pages (in bytes); any
+value lower than this limit will be ignored and the old configuration will be
+retained.
+
 ==============================================================
 
 dirty_expire_centisecs
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index e3d2c7dd59b9..ea78fa101ad6 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -103,6 +103,9 @@ static unsigned long one_ul = 1;
 static int one_hundred = 100;
 static int one_thousand = 1000;
 
+/* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
+static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
+
 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 static int maxolduid = 65535;
 static int minolduid;
@@ -1006,7 +1009,7 @@ static struct ctl_table vm_table[] = {
                 .mode           = 0644,
                 .proc_handler   = &dirty_bytes_handler,
                 .strategy       = &sysctl_intvec,
-                .extra1         = &one_ul,
+                .extra1         = &dirty_bytes_min,
         },
         {
                 .procname       = "dirty_writeback_centisecs",