From af9313c32c0fa2a0ac3b113669273833d60cc9de Mon Sep 17 00:00:00 2001 From: John Pittman Date: Thu, 21 Jun 2018 17:35:33 -0400 Subject: dm cache: only allow a single io_mode cache feature to be requested More than one io_mode feature can be requested when creating a dm cache device (as is: last one wins). The io_mode selections are incompatible with one another, we should force them to be selected exclusively. Add a counter to check for more than one io_mode selection. Fixes: 629d0a8a1a10 ("dm cache metadata: add "metadata2" feature") Signed-off-by: John Pittman Signed-off-by: Mike Snitzer --- drivers/md/dm-cache-target.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index ce14a3d1f609..44df244807e5 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 = "Duplicate cache io_mode features requested"; + return -EINVAL; + } + return 0; } -- cgit v1.2.3-58-ga151