Due to commit 629d0a8a1a10 ("dm cache metadata: add "metadata2" feature"),
when creating a dm cache device, more than one io_mode can be selected.
As the io_mode selections are incompatible with one another, we should
force them to be selected exclusively. Add simple ctr to check for
more than one io_mode selection.
Signed-off-by: John Pittman <jpittman@xxxxxxxxxx>
---
drivers/md/dm-cache-target.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index ce14a3d..45e3bed 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -2250,7 +2250,7 @@ static int parse_features(struct cache_args *ca, struct dm_arg_set *as,
{0, 2, "Invalid number of cache feature arguments"},
};
- int r;
+ int r, mode_ctr = 0;
unsigned argc;
const char *arg;
struct cache_features *cf = &ca->features;
@@ -2264,14 +2264,20 @@ static int parse_features(struct cache_args *ca, struct dm_arg_set *as,
while (argc--) {
arg = dm_shift_arg(as);
- if (!strcasecmp(arg, "writeback"))
+ if (!strcasecmp(arg, "writeback")) {
cf->io_mode = CM_IO_WRITEBACK;
+ mode_ctr++;
+ }
- else if (!strcasecmp(arg, "writethrough"))
+ else if (!strcasecmp(arg, "writethrough")) {
cf->io_mode = CM_IO_WRITETHROUGH;
+ mode_ctr++;
+ }
- else if (!strcasecmp(arg, "passthrough"))
+ else if (!strcasecmp(arg, "passthrough")) {
cf->io_mode = CM_IO_PASSTHROUGH;
+ mode_ctr++;
+ }
else if (!strcasecmp(arg, "metadata2"))
cf->metadata_version = 2;
@@ -2282,6 +2288,11 @@ static int parse_features(struct cache_args *ca, struct dm_arg_set *as,
}
}
+ if (mode_ctr > 1) {
+ *error = "Invalid number of cache io_mode features requested";
+ return -EINVAL;
+ }
+
return 0;
}
--
2.7.5
--
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