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    SubjectRe: [PATCH RFC v3] vfs: make fstatat retry once on ESTALE errors from getattr call
    Chuck Lever <> writes:

    > On Apr 23, 2012, at 10:51 AM, Miklos Szeredi wrote:
    >> "J. Bruce Fields" <> writes:
    >>> I also wonder whether it would be making too many assumptions about the
    >>> server or filesystem: just because ordinary posix interfaces don't allow
    >>> atomic replacement of a whole directory tree doesn't mean the server
    >>> might not have some way to do it.
    >> Exactly because posix limits the atomic replacement to empty directories
    >> is that this feature is not useful and is why linux can get away with
    >> the dead directory behavior in this case. And thinking about fixing
    >> this in NFS is completely pointless since no one will rely on the atomic
    >> replacement behavior. Fixing local filesystems is also pointless for
    >> the same reason.
    >> Atomic replacement of whole directory trees would indeed be more useful,
    >> but it's highly unlikely to be used anywhere since applications relying
    >> on this feature would be limited to special filesystems that allow this.
    > The cases I can think of have to do with file system restore, file
    > system and block device snapshots, and so on. This type of use case
    > may not practical on today's Linux server, but they are a reality for
    > anyone using high-end NFS storage.

    Problem with this is: if some directory file handles are stale (e.g. due
    to directories being removed, recreated, moved around) and on the client
    there are cwd-s referring to these handles, then they are going to
    become stale no matter what you do, even if the same path does exist
    after the restore on the server.


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      Last update: 2012-04-23 17:27    [W:0.024 / U:2.684 seconds]
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