Messages in this thread |  | | Date | Sun, 1 Sep 2002 21:40:32 +0200 | Subject | Re: [PATCH] Initial support for struct vfs_cred [0/1] | From | Trond Myklebust <> |
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>>>>> " " == Luca Barbieri <ldb@ldb.ods.org> writes:
> And, in the common case of open, why do you need to copy the > structure to check permissions? I think that open should just > check the current values. open might want to copy credentials
Because, as has been explained to you, we have things like Coda, Intermezzo, NFS, for which this is insufficient.
> in case you want to do the inode lookup asynchronously but then > it doesn't make sense to optimize for this since you already > have the huge disk read penalty. BTW, the 2.5.32 open does the > check in vfs_permission without copying anything. Anyway it's > just a 3 long copy plus an atomic inc vs. 1 long copy and > atomic inc. And if you don't need the groups array, it's just > a 2 longs copy that on some architectures with very slow atomic > operations (e.g. sparc) is much better.
But we we do need to check the groups array in the VFS. And as Linus pointed out, there is a good case for passing info from the user_struct too (crypto), etc...
Cheers, Trond - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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