Linux FAT File Creation/Birth Time Reporting, Proposal For Statx I/O Alignment Info

Back in 2017 for the Linux 4.11 kernel the statx system call was added for allowing enhanced file information reporting. Since then various file-systems began adding Statx support and worked its way up into Glibc and the like in user-space for Linux finally having file creation time reporting and other attributes. Two separate statx-related additions are now working their way to the kernel.

First up, queued into Andrew Morton's patch queue is creation time reporting for FAT file-systems. This is for proper file creation/birth time handling for FAT16/FAT32 file-systems on Linux. The Linux driver has reported a creation time "ctime" previously but ultimately muddled as the change time for a file as well.

With this patch expected to be merged for the upcoming Linux 5.19 cycle, FAT creation time is properly reported via statx now just like the creation/birth time reporting for the various other file-systems added in the years since this system call was introduced.

Separately, Google's Eric Biggers has proposed extending statx to be able to report I/O alignment information. The statx reporting for I/O alignment can be used by user-space for determining when a file supports direct I/O and the involved alignment details. This also allows ensuring user-space uses proper I/O alignment for a file. His "RFC" patch series adds the I/O alignment information to statx and wires it up for EXT4 and F2FS file-systems.