cifs: add warning about change in default cache semantics in 3.7

Add a warning that will be displayed when there is no cache= option
specified. We want to ensure that users are aware of the change in
defaults coming in 3.7.

Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 34186805e639af24ec37ef5e38f066319ca2e7fe..c49d49438c52ce677ca2cd67d3863afc5c694300 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1244,6 +1244,8 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
        char *string = NULL;
        char *tmp_end, *value;
        char delim;
+       bool cache_specified = false;
+       static bool cache_warned = false;
 
        separator[0] = ',';
        separator[1] = 0;
@@ -1455,6 +1457,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
                        vol->seal = 1;
                        break;
                case Opt_direct:
+                       cache_specified = true;
                        vol->direct_io = true;
                        vol->strict_io = false;
                        cERROR(1, "The \"directio\" option will be removed in "
@@ -1462,6 +1465,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
                                  "option.");
                        break;
                case Opt_strictcache:
+                       cache_specified = true;
                        vol->direct_io = false;
                        vol->strict_io = true;
                        cERROR(1, "The \"strictcache\" option will be removed "
@@ -1888,6 +1892,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
                                goto cifs_parse_mount_err;
                        break;
                case Opt_cache:
+                       cache_specified = true;
                        string = match_strdup(args);
                        if (string == NULL)
                                goto out_nomem;
@@ -1938,6 +1943,14 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
                printk(KERN_NOTICE "CIFS: ignoring forcegid mount option "
                                   "specified with no gid= option.\n");
 
+       /* FIXME: remove this block in 3.7 */
+       if (!cache_specified && !cache_warned) {
+               cache_warned = true;
+               printk(KERN_NOTICE "CIFS: no cache= option specified, using "
+                                  "\"cache=loose\". This default will change "
+                                  "to \"cache=strict\" in 3.7.\n");
+       }
+
        kfree(mountdata_copy);
        return 0;