On 04/02/2014 06:38 AM, Konstantin Khlebnikov wrote: > On Wed, Mar 19, 2014 at 11:06 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 explicitly allows 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() does not create a front-FD, but instead returns the raw >> shmem file, so calls like ftruncate() can be used. Also calls like fstat() >> will return proper information and mark the file as regular file. Sealing >> is explicitly supported on memfds. >> >> Compared to O_TMPFILE, it does not require a tmpfs mount-point and is not >> subject to quotas and alike. > > Instead of adding new syscall we can extend existing openat() a little > bit more: > > openat(AT_FDSHM, "name", O_TMPFILE | O_RDWR, 0666) Please don't. O_TMPFILE is a messy enough API, and the last thing we need to do is to extend it. If we want a fancy API for creating new inodes with no corresponding dentry, let's create one. Otherwise, let's just stick with a special-purpose API for these shm files. --Andy -- 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>