On Thu, Aug 08, 2024 at 03:27:02PM -0400, Josef Bacik wrote: > v1: https://lore.kernel.org/linux-fsdevel/cover.1721931241.git.josef@xxxxxxxxxxxxxx/ > > v1->v2: > - reworked the page fault logic based on Jan's suggestion and turned it into a > helper. > - Added 3 patches per-fs where we need to call the fsnotify helper from their > ->fault handlers. > - Disabled readahead in the case that there's a pre-content watch in place. > - Disabled huge faults when there's a pre-content watch in place (entirely > because it's untested, theoretically it should be straightforward to do). > - Updated the command numbers. > - Addressed the random spelling/grammer mistakes that Jan pointed out. > - Addressed the other random nits from Jan. > > --- Original email --- > > Hello, > > These are the patches for the bare bones pre-content fanotify support. The > majority of this work is Amir's, my contribution to this has solely been around > adding the page fault hooks, testing and validating everything. I'm sending it > because Amir is traveling a bunch, and I touched it last so I'm going to take > all the hate and he can take all the credit. Brave man. :) > There is a PoC that I've been using to validate this work, you can find the git > repo here > > https://github.com/josefbacik/remote-fetch > > This consists of 3 different tools. > > 1. populate. This just creates all the stub files in the directory from the > source directory. Just run ./populate ~/linux ~/hsm-linux and it'll > recursively create all of the stub files and directories. > 2. remote-fetch. This is the actual PoC, you just point it at the source and > destination directory and then you can do whatever. ./remote-fetch ~/linux > ~/hsm-linux. > 3. mmap-validate. This was to validate the pagefault thing, this is likely what > will be turned into the selftest with remote-fetch. It creates a file and > then you can validate the file matches the right pattern with both normal > reads and mmap. Normally I do something like > > ./mmap-validate create ~/src/foo > ./populate ~/src ~/dst > ./rmeote-fetch ~/src ~/dst > ./mmap-validate validate ~/dst/foo This smells like something that should be added to fstests. FWIW, fstests used to have a whole "fake-hsm" infrastructure subsystem in it for testing DMAPI events used by HSMs. They were removed in this commit: commit 6497ede7ad4e9fc8e5a5a121bd600df896b7d9c6 Author: Darrick J. Wong <djwong@xxxxxxxxxx> Date: Thu Feb 11 13:33:38 2021 -0800 fstests: remove DMAPI tests Upstream XFS has never supported DMAPI, so remove the tests for this feature. Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> Acked-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Eryu Guan <guaneryu@xxxxxxxxx> See ./dmapi/src/sample_hsm/ for the HSM test code that was removed in that patchset - it might provide some infrastructure that can be used to test the fanotify HSM event infrastructure without reinventing the entire wheel... -Dave. -- Dave Chinner david@xxxxxxxxxxxxx
