In the past it either used to be NULL or the "older" backend. Now we also return -Exx error codes. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> --- drivers/staging/zcache/zcache-main.c | 5 ++++- drivers/xen/tmem.c | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c index 288c841..79c10af 100644 --- a/drivers/staging/zcache/zcache-main.c +++ b/drivers/staging/zcache/zcache-main.c @@ -1826,8 +1826,11 @@ static int zcache_init(void) namestr, frontswap_has_exclusive_gets, !disable_frontswap_ignore_nonactive); #endif - if (old_ops != NULL) + if (IS_ERR(old_ops) || old_ops) { + if (IS_ERR(old_ops)) + return PTR_RET(old_ops); pr_warn("%s: frontswap_ops overridden\n", namestr); + } } if (ramster_enabled) ramster_init(!disable_cleancache, !disable_frontswap, diff --git a/drivers/xen/tmem.c b/drivers/xen/tmem.c index 9a4a9ec..2f939e5 100644 --- a/drivers/xen/tmem.c +++ b/drivers/xen/tmem.c @@ -395,8 +395,11 @@ static int xen_tmem_init(void) frontswap_register_ops(&tmem_frontswap_ops); tmem_frontswap_poolid = -1; - if (old_ops) + if (IS_ERR(old_ops) || old_ops) { + if (IS_ERR(old_ops)) + return PTR_ERR(old_ops); s = " (WARNING: frontswap_ops overridden)"; + } printk(KERN_INFO "frontswap enabled, RAM provided by " "Xen Transcendent Memory\n"); } -- 1.7.11.7 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>