Re: [PATCH 1/5] cramfs: direct memory access support

2017-08-13 Thread Nicolas Pitre
On Sat, 12 Aug 2017, Christoph Hellwig wrote: > Direct physical memory access in a file system is never safe. > Please make sure this goes through struct dax_operations. Well, after having a closer look, I don't think dax might be relevant here for a couple reasons: - cramfs is read-only. No co

Re: [PATCH 1/5] cramfs: direct memory access support

2017-08-12 Thread Christoph Hellwig
Direct physical memory access in a file system is never safe. Please make sure this goes through struct dax_operations.

[PATCH 1/5] cramfs: direct memory access support

2017-08-11 Thread Nicolas Pitre
Small embedded systems typically execute the kernel code in place (XIP) directly from flash to save on precious RAM usage. This adds the ability to consume filesystem data directly from flash to the cramfs filesystem as well. Cramfs is particularly well suited to this feature as it is very simple a