On Thu, Sep 05, 2002 at 09:06:00PM +0200, Andrea Arcangeli wrote:
> On Thu, Sep 05, 2002 at 07:48:24PM +0100, Christoph Hellwig wrote:
> > On Thu, Sep 05, 2002 at 08:41:25PM +0200, Andrea Arcangeli wrote:
> > > other fs, if you're not holding the i_sem (and you certainly aren't
> > > holding the i_sem that frequently, you don't even for writes).
> >
> > Except of O_DIRECT writes we _do_ hold i_sem, btw.
>
> can't you end with this?
>
> O_DIRECT write
> write finishes
> truncate drops the write
> truncate set i_sem to 0
> write set i_sem to something
s/i_sem/i_size/g ?
> and the fs is then corrupt? (very minor corruption of course and
> extremely hard to trigger, trivially solvable by an fsck, ext[23] had
> similar issues too with the get_block failures with < PAGE_SIZE
> softblocksize, fixed around 2.4.19, that was certainly easier to
> reproduce btw)
Won't happen:
O_DIRECT write starts
+ takes XFS iolock exclusive
- invalidates pagecache
+ downgrades iolock to shared
- perform write
xfs_setattr for truncate called
+ takes XFS iolock shared
-> blocks
- write i_size to something
+ releases iolock
-> gets woken
-
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This archive was generated by hypermail 2b29 : Sat Sep 07 2002 - 22:00:26 EST