nfsd grace period open owners
Subsystems (2)
Hi Bruce,
I'm updating my fault injection patches to work with your recent stateid changes, and I had a question about something I'm seeing on the server. When I reboot the server it will enter a grace period and reply to any OPEN requests from the client with NFSERR_GRACE. I used Wireshark to see that NFSERR_GRACE is returned 12 times before the open succeeds, so 13 OPEN requests total. When I send the command to forget all open owners I find that 13 open owners have been forgotten, but I only expecting to find 1. Is this what you would expect the server to do?
I've pasted the code I use to count and delete open owners below. The variable "num" has the value 0, so all open owners should be deleted.
- Bryan
static int nfsd_forget_n_openowners(u64 num)
{
int i, count = 0;
struct nfs4_stateowner *sop, *next;
for (i = 0; i < OPEN_OWNER_HASH_SIZE; i++) {
list_for_each_entry_safe(sop, next, &open_ownerstr_hashtbl[i], so_strhash) {
release_openowner(openowner(sop));
if (++count == num)
return count;
}
}
return count;
}void nfsd_forget_openowners(u64 num)
{
int count;
nfs4_lock_state();
count = nfsd_forget_n_openowners(num);
nfs4_unlock_state();
printk(KERN_INFO "%s %s Forgot %d open owners", __FILE__, __func__, count);
}Quoted 3 lines · Bryan Schumaker
Hi Bruce,
I'm updating my fault injection patches to work with your recent stateid changes, and I had a question about something I'm seeing on the server. When I reboot the server it will enter a grace period and reply to any OPEN requests from the client with
NFSERR_GRACE. I used Wireshark to see thatNFSERR_GRACEis returned 12 times before the open succeeds, so 13 OPEN requests total. When I send the command to forget all open owners I find that 13 open owners have been forgotten, but I only expecting to find 1. Is this what you would expect the server to do?
Huh. No, that doesn't sound right. A failed open doesn't confirm the openowner, and I don't think there's any reason to keep around an unconfirmed openowner.
Out of curiosity, is the client using a different openowner for each open?
--b.
Quoted 30 lines
I've pasted the code I use to count and delete open owners below. The variable "num" has the value 0, so all open owners should be deleted.
- Bryan
static int
nfsd_forget_n_openowners(u64 num){ int i, count = 0; struct nfs4_stateowner *sop, *next; for (i = 0; i < OPEN_OWNER_HASH_SIZE; i++) { list_for_each_entry_safe(sop, next, &open_ownerstr_hashtbl[i], so_strhash) { release_openowner(openowner(sop)); if (++count == num) return count; } } return count; }void
nfsd_forget_openowners(u64 num){ int count; nfs4_lock_state(); count = nfsd_forget_n_openowners(num); nfs4_unlock_state(); printk(KERN_INFO "%s %s Forgot %d open owners", __FILE__, __func__, count); }
Quoted 8 lines · J. Bruce Fields
Quoted 3 lines · Bryan Schumaker
Hi Bruce,
I'm updating my fault injection patches to work with your recent stateid changes, and I had a question about something I'm seeing on the server. When I reboot the server it will enter a grace period and reply to any OPEN requests from the client with
NFSERR_GRACE. I used Wireshark to see thatNFSERR_GRACEis returned 12 times before the open succeeds, so 13 OPEN requests total. When I send the command to forget all open owners I find that 13 open owners have been forgotten, but I only expecting to find 1. Is this what you would expect the server to do?Huh. No, that doesn't sound right. A failed open doesn't confirm the openowner, and I don't think there's any reason to keep around an unconfirmed openowner.
Makes sense to me.
Quoted 3 lines
Out of curiosity, is the client using a different openowner for each open?
Yeah, looks like the client is using a different one for each attempt.
- Bryan
Quoted 33 lines
--b.
Quoted 30 lines
I've pasted the code I use to count and delete open owners below. The variable "num" has the value 0, so all open owners should be deleted.
- Bryan
static int
nfsd_forget_n_openowners(u64 num){ int i, count = 0; struct nfs4_stateowner *sop, *next; for (i = 0; i < OPEN_OWNER_HASH_SIZE; i++) { list_for_each_entry_safe(sop, next, &open_ownerstr_hashtbl[i], so_strhash) { release_openowner(openowner(sop)); if (++count == num) return count; } } return count; }void
nfsd_forget_openowners(u64 num){ int count; nfs4_lock_state(); count = nfsd_forget_n_openowners(num); nfs4_unlock_state(); printk(KERN_INFO "%s %s Forgot %d open owners", __FILE__, __func__, count); }
Quoted 10 lines · Bryan Schumaker
Quoted 8 lines · J. Bruce Fields
Quoted 3 lines · Bryan Schumaker
Hi Bruce,
I'm updating my fault injection patches to work with your recent stateid changes, and I had a question about something I'm seeing on the server. When I reboot the server it will enter a grace period and reply to any OPEN requests from the client with
NFSERR_GRACE. I used Wireshark to see thatNFSERR_GRACEis returned 12 times before the open succeeds, so 13 OPEN requests total. When I send the command to forget all open owners I find that 13 open owners have been forgotten, but I only expecting to find 1. Is this what you would expect the server to do?Huh. No, that doesn't sound right. A failed open doesn't confirm the openowner, and I don't think there's any reason to keep around an unconfirmed openowner.
Quoted 7 lines
Makes sense to me.
Quoted 3 lines
Out of curiosity, is the client using a different openowner for each open?
Yeah, looks like the client is using a different one for each attempt.
Makes sense. Yes, so it's the obvious problem--we create a new openowner early in the OPEN processing but don't clean it up on failure.
I'm not sure how to fix it. By the time we fail later on, we've lost track of whether the openowner is one we created for this open or not.
Well, wait, I suppose in the former case it will still be unconfirmed. So probably we should just free op_openowner on exit from open if it's unconfirmed.
--b.