Namjae Jeon <linkinj...@gmail.com> writes: > Yes, It is true(current VFAT of -mm tree is not stable). Although we > set lookupcache=none while mounting, ESTALE error can still occur in > rename case. > So there still remain ESTALE error issue from rename case on current -mm tree. > plz See the step as the following > 1. on client write to file. > 2. on client, move/rename file. > 3. on server, do drop_caches. etc to somehow evict indoe number so > that it gets new inode number > 4. on client, resume the program to write to file. write will fail > (write: Stale NFS file handle)
Since rename() will be disabled on stable ino patches, this will be unfixable, so rather maybe it is worse. Did you checked why it returns -ESTALE? Or rename() issue also is unfixable on -mm? > And ...... > If we mount NFS with lookupcache=none, FAT file lookup performance is > severely dropped. > LOOKUP performance is very poor on slow network and slow device. I do > not recommend to disable lookup cache on NFS. > And that is why reconstructing inode is already implemented in other > filesystem (e.g. EXT4, XFS etc..) > Currently lookupcache is enabled by default in NFS, it means users > already have disclosed and experienced ESTALE issues on NFS over VFAT. > > I agree wth you to make NFS over VFAT read-only filesystem to avoid all > issues. > Eventually we can make it writable with rename limitation when we > decide that it is pretty stable in mainline. > So, I suggest to add 'nfs_ro' mount option instead of 'nfs' option. -mm seems to be more stable than I thought. As he said, sounds like rename() is an only known issue on -mm, true? And are you tried https://lkml.org/lkml/2012/6/29/381 patches? It sounds like to improve performance by enabling lookupcache. I'd like to be knowing the critical reason we have to replace it. Thanks. -- OGAWA Hirofumi <hirof...@mail.parknet.co.jp> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
