Hi On Fri, Jun 13, 2014 at 4:20 PM, Michael Kerrisk (man-pages) <mtk.manpages@xxxxxxxxx> wrote: > Hi David, > > On Fri, Jun 13, 2014 at 2:41 PM, David Herrmann <dh.herrmann@xxxxxxxxx> wrote: >> Hi >> >> On Fri, Jun 13, 2014 at 2:27 PM, Michael Kerrisk (man-pages) >> <mtk.manpages@xxxxxxxxx> wrote: >>> Hi David, >>> >>> On Fri, Jun 13, 2014 at 12:36 PM, David Herrmann <dh.herrmann@xxxxxxxxx> wrote: >>>> memfd_create() is similar to mmap(MAP_ANON), but returns a file-descriptor >>>> that you can pass to mmap(). It can support sealing and avoids any >>>> connection to user-visible mount-points. Thus, it's not subject to quotas >>>> on mounted file-systems, but can be used like malloc()'ed memory, but >>>> with a file-descriptor to it. >>>> >>>> memfd_create() returns the raw shmem file, so calls like ftruncate() can >>>> be used to modify the underlying inode. Also calls like fstat() >>>> will return proper information and mark the file as regular file. If you >>>> want sealing, you can specify MFD_ALLOW_SEALING. Otherwise, sealing is not >>>> supported (like on all other regular files). >>>> >>>> Compared to O_TMPFILE, it does not require a tmpfs mount-point and is not >>>> subject to quotas and alike. It is still properly accounted to memcg >>>> limits, though. >>> >>> Where do I find / is there detailed documentation (ideally, a man >>> page) for this new system call? >> >> I did write a man-page proposal for memfd_create() and a patch for >> fcntl() for v1, > > Ahh -- that's why I had a recollection of such a page ;-). > >> however, the API changed several times so I didn't >> keep them up to date (the man-page patches are on LKML). However, I >> wrote a short introduction to memfd+sealing v3, that I recommend >> reading first: >> http://dvdhrm.wordpress.com/2014/06/10/memfd_create2/ > > Yes, I saw it already. (It's good, but I want more.) Sorry, totally forgot about that one. I now pushed the man-pages out. They're available here: http://cgit.freedesktop.org/~dvdhrm/man-pages/log/?h=memfd Thanks! David -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
