From: Bryan Schumaker <[email protected]>
I put the client into an open recovery loop by:
Client: Open file
read half
Server: Expire client (echo 0 > /sys/kernel/debug/nfsd/forget_clients)
Client: Drop vm cache (echo 3 > /proc/sys/vm/drop_caches)
finish reading file
This causes a loop because the client never updates the nfs4_state after
discovering that the delegation is invalid. This means it will keep
trying to read using the bad delegation rather than attempting to re-open
the file.
Signed-off-by: Bryan Schumaker <[email protected]>
CC: [email protected] [3.4+]
---
fs/nfs/nfs4proc.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1e50326..1d49168 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1774,7 +1774,11 @@ static void nfs41_clear_delegation_stateid(struct nfs4_state *state)
* informs us the stateid is unrecognized. */
if (status != -NFS4ERR_BAD_STATEID)
nfs41_free_stateid(server, stateid);
+ nfs_remove_bad_delegation(state->inode);
+ write_seqlock(&state->seqlock);
+ nfs4_stateid_copy(&state->stateid, &state->open_stateid);
+ write_sequnlock(&state->seqlock);
clear_bit(NFS_DELEGATED_STATE, &state->flags);
}
}
--
1.7.12.1
On Wed, Sep 26, 2012 at 9:25 PM, <[email protected]> wrote:
> This causes a loop because the client never updates the nfs4_state after
> discovering that the delegation is invalid. This means it will keep
> trying to read using the bad delegation rather than attempting to re-open
> the file.
Oh, I already encountered this bug but never found the time to debug
it / report it.
Thanks a lot! I'll try to test it soon.
--
William
On Thu, Sep 27, 2012 at 2:35 PM, Bryan Schumaker <[email protected]> wrote:
> Awesome! Let me know how your tests go, thanks.
Oh I didn't saw it was nfs4.1 specific since the header shows "NFS:
Remove bad delegations during open recovery"
Sorry, I thought about a general nfs bug.
Regards,
--
William
From: Bryan Schumaker <[email protected]>
If we are reading through a delegation, and the delegation is OK then
state->stateid will still point to a delegation stateid and not an open
stateid.
Signed-off-by: Bryan Schumaker <[email protected]>
---
fs/nfs/nfs4proc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1d49168..f35c243 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1794,7 +1794,7 @@ static void nfs41_clear_delegation_stateid(struct nfs4_state *state)
static int nfs41_check_open_stateid(struct nfs4_state *state)
{
struct nfs_server *server = NFS_SERVER(state->inode);
- nfs4_stateid *stateid = &state->stateid;
+ nfs4_stateid *stateid = &state->open_stateid;
int status;
/* If a state reset has been done, test_stateid is unneeded */
--
1.7.12.1
On 09/26/2012 06:19 PM, William Dauchy wrote:
> On Wed, Sep 26, 2012 at 9:25 PM, <[email protected]> wrote:
>> This causes a loop because the client never updates the nfs4_state after
>> discovering that the delegation is invalid. This means it will keep
>> trying to read using the bad delegation rather than attempting to re-open
>> the file.
>
> Oh, I already encountered this bug but never found the time to debug
> it / report it.
>
> Thanks a lot! I'll try to test it soon.
>
Awesome! Let me know how your tests go, thanks.
- Bryan