On Tue, Dec 31, 2024 at 5:03 PM Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > On Tue, Dec 31, 2024 at 4:36 AM Prince Kumar <princer@xxxxxxxxxx> wrote: > > > > Thanks Bernd for looking into this! > > > > I think 6.9 added passthrough support. Are you using that? > > > Not yet, but we have plans to try this out. > > > > FOPEN_CACHE_DIR is default when there is no fuse-server open method > > defined - does your implementation have an open/dir_open? > > > Yes, here is the implementation in GCSFuse (internally uses jacobsa/fuse library) - https://github.com/GoogleCloudPlatform/gcsfuse/blob/b0ca9c5b2c0a35aeb8a48fe7a36120d7b33216aa/internal/fs/fs.go#L2328 > > Here, op.CacheDir maps to FOPEN_CACHE_DIR and op.KeepCache maps to > > FOPEN_KEEP_CACHE. > > > > I think the only user of FOPEN_CACHE_DIR is in fs/fuse/readdir.c and > > that always checks if it is set - either the flag gets set or does not > > come into role at all, because passthrough is used? > > > Being honest, I don't have much idea of linux source code. As a user, to me the FOPEN_CACHE_DIR flag is working as expected. > > The problem is with the FOPEN_KEEP_CACHE flags, setting this should > > evict the dir cache, but it's not happening for linux 6.9.x and above. > > Although I see a line in fs/fuse/dir.c > > (https://github.com/torvalds/linux/blob/ccb98ccef0e543c2bd4ef1a72270461957f3d8d0/fs/fuse/dir.c#L718) > > which invalidates the inode pages if FOPEN_KEEP_CACHE is not set. > > > > So my ultimate question would be: > > (1) Do you see such recent changes in fs/fuse which explains the above > > regression? > > (2) If the changes are intentional, what should be the right way for > > fuse-server to evict the dir-cache (other than auto eviction due to > > change in dir-content, e.g., addition of new file inside a dir)? > > > > Hi Prince, > > The change is not international. > It is a regression due to commit > 7de64d521bf92 ("fuse: break up fuse_open_common()") that missed the fact > the fuse_dir_open() may need to clean the page cache. > > Can you test the attached fix patch? > It is only compile tested. > Due to holidays, I had no time to verify the fix. > Miklos, FYI, in case you plan to send a fixes PR, pushed my untested patch to branch fuse-fixes in my github. Prince, if you can, please provide Tested-by. Thanks, Amir.
