diff options
Diffstat (limited to 'drivers/dax/super.c')
| -rw-r--r-- | drivers/dax/super.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/dax/super.c b/drivers/dax/super.c index a0244f6bb44b..aca71d7fccc1 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -13,6 +13,7 @@ #include <linux/uio.h> #include <linux/dax.h> #include <linux/fs.h> +#include <linux/cacheinfo.h> #include "dax-private.h" /** @@ -319,6 +320,11 @@ EXPORT_SYMBOL_GPL(dax_alive); * that any fault handlers or operations that might have seen * dax_alive(), have completed. Any operations that start after * synchronize_srcu() has run will abort upon seeing !dax_alive(). + * + * Note, because alloc_dax() returns an ERR_PTR() on error, callers + * typically store its result into a local variable in order to check + * the result. Therefore, care must be taken to populate the struct + * device dax_dev field make sure the dax_dev is not leaked. */ void kill_dax(struct dax_device *dax_dev) { @@ -446,6 +452,14 @@ struct dax_device *alloc_dax(void *private, const struct dax_operations *ops) dev_t devt; int minor; + /* + * Unavailable on architectures with virtually aliased data caches, + * except for device-dax (NULL operations pointer), which does + * not use aliased mappings from the kernel. + */ + if (ops && cpu_dcache_is_aliasing()) + return ERR_PTR(-EOPNOTSUPP); + if (WARN_ON_ONCE(ops && !ops->zero_page_range)) return ERR_PTR(-EINVAL); |