Hi trond, Because My mail system cant receive nfs mail list’s mails, I reply your patch here. I have some question for the patch. >No. Basic O_DIRECT does not guarantee atomicity of requests, which is >why we do not have generic locking at the VFS level when reading and >writing. The only guarantee being offered is that O_DIRECT and buffered >writes do not collide. Do you mean other fs also cant guarantee atomicity of O_DIRECT request or just nfs? >IOW: I think the basic premise for this test is just broken (as I >commented in the patch series I sent) because it is assuming a >behaviour that is simply not guaranteed. So the generic/465 of xfstests can’t apply to nfs for now, am I right? >BTW: note that buffered writes have the same property. They are ordered >when being written into the page cache, meaning that reads on the same >client will see no holes, however if you try to read from another >client, then you will see the same behaviour, with temporary holes >magically appearing in the file. As you say, nfs buffered write also has the hole problem with multiple r/w on different clients. I want to know if the problem exists in other local fs such as xfs,ext4? Thanks in advance.
