Messages in this thread | | | Date | Thu, 11 Feb 2010 03:02:54 +0000 | From | Al Viro <> | Subject | Re: [WTF] ... is going on with current->fs->{root,mnt} accesses in pohmelfs |
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On Thu, Feb 11, 2010 at 12:29:33AM +0300, Evgeniy Polyakov wrote: > On Wed, Feb 10, 2010 at 09:02:48PM +0000, Al Viro (viro@ZenIV.linux.org.uk) wrote: > > Which would be... ? E.g. between writepages() and rename(). What serializes > > your write_inode_create() wrt renames? IOW, how can the server decide that > > data from writepages() should go to the same object regardless of the > > rename? > > rename and some other metadata operations as well as write itself > request remote lock (if not grabbed already), acknowledge forces writeback to old path.
Um. You do realize that d_move() happens with none of your locks held, right? It's done in vfs_rename_{other,dir}() and the only thing held is s_vfs_rename_sem and i_mutex on parents. How could your code in writeback be able to distinguish
rename() is done d_move() has happened, we see new pathname in dcache
from
rename() is done d_move() has not yet happened, we see old pathname in dcache
and generate the right on-the-wire traffic in both cases? Note that here server has already seen rename request; as far as server and client are concerned the rename() is over.
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