On Wed, 15 Apr 2009, Derrick Brashear wrote:
On Wed, Apr 15, 2009 at 5:44 AM, Felix Frank <[email protected]> wrote:
On a hunch, I applied this to 1.4.8:
--- src/afs/LINUX/osi_vm.c.orig 2009-04-15 11:37:49.000000000 +0200
+++ src/afs/LINUX/osi_vm.c 2009-04-15 11:38:56.000000000 +0200
@@ -102,11 +102,6 @@ osi_VM_StoreAllSegments(struct vcache *a
{
struct inode *ip = AFSTOV(avc);
- if (!avc->states & CPageWrite)
- avc->states |= CPageWrite;
- else - return; /* someone already writing */
-
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,5)
/* filemap_fdatasync() only exported in 2.4.5 and above */
ReleaseWriteLock(&avc->lock);
@@ -120,7 +115,6 @@ osi_VM_StoreAllSegments(struct vcache *a
AFS_GLOCK();
ObtainWriteLock(&avc->lock, 121);
#endif
- avc->states &= ~CPageWrite;
}
/* Purge VM for a file when its callback is revoked.
This apparently solved the problem for 1.4.8 w/ disk cache. Will try 1.4.10
as well. BCC'ing openafs-bugs now.
The problem without that is a deadlock as described in RT 120491,
which means either this or that needs to be solved in another way.
Looking through my local pile of things to deal with, I see Chaskiel
commented thus:
"What's there seems like it will prevent recursion, but in a silly
way. The whole point of calling filemap_fdatawrite
is for the kernel to call writepage() on all the dirty pages. But
since osi_VM_StoreAllSegments always sets CPageWrite and CPageWrite
means writepage always returns WRITEPAGE_ACTIVATE, there's no point.
Wouldn't it be better
for a DoPartialWrite-driven StoreAllSegments to not call
osi_VM_StoreAllSegments (and restore the latter to usefulness)?"
If you wish to/can look, please do, otherwise I will as soon as I can.
All right. I'll see what I can do, but I still haven't got my head
around most of the client code.
Felix
