On Jun. 08, 2010, 0:11 +0300, Alexandros Batsakis <batsakis@xxxxxxxxxx> wrote:
> Forgetful client model:
>
> If we receive a CB_LAYOUTRECALL
> - we spawn a thread to handle the recall
> (xxx: now only one recall can be active at a time, else NFS4ERR_DELAY)
> - we check the stateid seqid
> if it does not match we return NFS4ERR_DELAY
> - we check for pending I/O
> if there is we return NFS4ERR_DELAY
> Else we return NO_MATCHING_LAYOUT.
> Note that for whole file layouts there is no need to serialize LAYOUTGETs/LAYOUTRETURNs
> For bulk layouts, if there is a layout active, we return NFS4_OK and we start
> cleaning the layouts asynchronously. At the end we send a bulk LAYOUTRETURN.
> Note that there is no need to prevent any new LAYOUTGETs explicitly as the server should reject them.
>
> Signed-off-by: Alexandros Batsakis <batsakis@xxxxxxxxxx>
> ---
> fs/nfs/callback_proc.c | 146 ++++++++++++++++++++++++++++++++++--------------
> fs/nfs/nfs4_fs.h | 1 +
> fs/nfs/pnfs.c | 70 ++++++++++-------------
> 3 files changed, 136 insertions(+), 81 deletions(-)
>
> diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
> index 3bae785..af7a01d 100644
> --- a/fs/nfs/callback_proc.c
> +++ b/fs/nfs/callback_proc.c
> @@ -129,6 +129,38 @@ int nfs4_validate_delegation_stateid(struct nfs_delegation *delegation, const nf
>
> #if defined(CONFIG_NFS_V4_1)
>
> +static bool
> +pnfs_is_next_layout_stateid(const struct pnfs_layout_type *lo,
> + const nfs4_stateid stateid)
> +{
> + int seqlock;
> + bool res;
> + u32 oldseqid, newseqid;
> +
> + do {
> + seqlock = read_seqbegin(&lo->seqlock);
> + oldseqid = be32_to_cpu(lo->stateid.u.stateid.seqid);
> + newseqid = be32_to_cpu(stateid.u.stateid.seqid);
> + res = !memcmp(lo->stateid.u.stateid.other,
> + stateid.u.stateid.other,
> + NFS4_STATEID_OTHER_SIZE);
> + if (res) { /* comparing layout stateids */
> + if (oldseqid == ~0)
> + res = (newseqid == 1);
> + else
> + res = (newseqid == oldseqid + 1);
> + } else { /* open stateid */
> + res = !memcmp(lo->stateid.u.data,
> + &zero_stateid,
> + NFS4_STATEID_SIZE);
> + if (res)
> + res = (newseqid == 1);
> + }
> + } while (read_seqretry(&lo->seqlock, seqlock));
> +
> + return res;
> +}
> +
> /*
> * Retrieve an inode based on layout recall parameters
> *
> @@ -191,9 +223,10 @@ static int pnfs_recall_layout(void *data)
> struct inode *inode, *ino;
> struct nfs_client *clp;
> struct cb_pnfs_layoutrecallargs rl;
> + struct nfs4_pnfs_layoutreturn *lrp;
> struct recall_layout_threadargs *args =
> (struct recall_layout_threadargs *)data;
> - int status;
> + int status = 0;
>
> daemonize("nfsv4-layoutreturn");
>
> @@ -204,47 +237,59 @@ static int pnfs_recall_layout(void *data)
> clp = args->clp;
> inode = args->inode;
> rl = *args->rl;
> - args->result = 0;
> - complete(&args->started);
> - args = NULL;
> - /* Note: args must not be used after this point!!! */
> -
> -/* FIXME: need barrier here:
> - pause I/O to data servers
> - pause layoutgets
> - drain all outstanding writes to storage devices
> - wait for any outstanding layoutreturns and layoutgets mentioned in
> - cb_sequence.
> - then return layouts, resume after layoutreturns complete
> - */
>
> /* support whole file layouts only */
> rl.cbl_seg.offset = 0;
> rl.cbl_seg.length = NFS4_MAX_UINT64;
>
> if (rl.cbl_recall_type == RETURN_FILE) {
> - status = pnfs_return_layout(inode, &rl.cbl_seg, &rl.cbl_stateid,
> - RETURN_FILE, true);
> + if (pnfs_is_next_layout_stateid(&NFS_I(inode)->layout,
> + rl.cbl_stateid))
> + status = pnfs_return_layout(inode, &rl.cbl_seg,
> + &rl.cbl_stateid, RETURN_FILE,
> + false);
> + else
> + status = cpu_to_be32(NFS4ERR_DELAY);
> if (status)
> dprintk("%s RETURN_FILE error: %d\n", __func__, status);
> + else
> + status = cpu_to_be32(NFS4ERR_NOMATCHING_LAYOUT);
> + args->result = status;
> + complete(&args->started);
> goto out;
> }
>
> - /* FIXME: This loop is inefficient, running in O(|s_inodes|^2) */
> + status = cpu_to_be32(NFS4_OK);
> + args->result = status;
> + complete(&args->started);
> + args = NULL;
> +
> + /* IMPROVEME: This loop is inefficient, running in O(|s_inodes|^2) */
> while ((ino = nfs_layoutrecall_find_inode(clp, &rl)) != NULL) {
> - /* XXX need to check status on pnfs_return_layout */
> - pnfs_return_layout(ino, &rl.cbl_seg, NULL, RETURN_FILE, true);
> + /* FIXME: need to check status on pnfs_return_layout */
> + pnfs_return_layout(ino, &rl.cbl_seg, NULL, RETURN_FILE, false);
> iput(ino);
> }
>
> + lrp = kzalloc(sizeof(*lrp), GFP_KERNEL);
> + if (!lrp) {
> + dprintk("%s: allocation failed. Cannot send last LAYOUTRETURN\n",
> + __func__);
> + goto out;
> + }
> +
> /* send final layoutreturn */
> - status = pnfs_return_layout(inode, &rl.cbl_seg, NULL,
> - rl.cbl_recall_type, true);
> - if (status)
> - printk(KERN_INFO "%s: ignoring pnfs_return_layout status=%d\n",
> - __func__, status);
> + lrp->args.reclaim = 0;
> + lrp->args.layout_type = rl.cbl_layout_type;
> + lrp->args.return_type = rl.cbl_recall_type;
> + lrp->args.lseg = rl.cbl_seg;
> + lrp->args.inode = inode;
> + lrp->lo = NULL;
> + pnfs4_proc_layoutreturn(lrp, true);
> +
> out:
> - iput(inode);
> + clear_bit(NFS4CLNT_LAYOUT_RECALL, &clp->cl_state);
> + nfs_put_client(clp);
> module_put_and_exit(0);
> dprintk("%s: exit status %d\n", __func__, 0);
> return 0;
> @@ -262,15 +307,18 @@ static int pnfs_async_return_layout(struct nfs_client *clp, struct inode *inode,
> .rl = rl,
> };
> struct task_struct *t;
> - int status;
> -
> - /* should have returned NFS4ERR_NOMATCHING_LAYOUT... */
> - BUG_ON(inode == NULL);
> + int status = -EAGAIN;
>
> dprintk("%s: -->\n", __func__);
>
> + /* FIXME: do not allow two concurrent layout recalls */
> + if (test_and_set_bit(NFS4CLNT_LAYOUT_RECALL, &clp->cl_state))
> + return status;
> +
> init_completion(&data.started);
> __module_get(THIS_MODULE);
> + if (!atomic_inc_not_zero(&clp->cl_count))
> + goto out_put_no_client;
>
> t = kthread_run(pnfs_recall_layout, &data, "%s", "pnfs_recall_layout");
> if (IS_ERR(t)) {
> @@ -284,6 +332,9 @@ static int pnfs_async_return_layout(struct nfs_client *clp, struct inode *inode,
> wait_for_completion(&data.started);
> return data.result;
> out_module_put:
> + nfs_put_client(clp);
> +out_put_no_client:
> + clear_bit(NFS4CLNT_LAYOUT_RECALL, &clp->cl_state);
> module_put(THIS_MODULE);
> return status;
> }
> @@ -294,35 +345,46 @@ __be32 pnfs_cb_layoutrecall(struct cb_pnfs_layoutrecallargs *args,
> struct nfs_client *clp;
> struct inode *inode = NULL;
> __be32 res;
> + int status;
> unsigned int num_client = 0;
>
> dprintk("%s: -->\n", __func__);
>
> - res = htonl(NFS4ERR_INVAL);
> - clp = nfs_find_client(args->cbl_addr, 4);
> + res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
> + clp = nfs_find_client(args->cbl_addr, 4);
> if (clp == NULL) {
> dprintk("%s: no client for addr %u.%u.%u.%u\n",
> __func__, NIPQUAD(args->cbl_addr));
> goto out;
> }
>
> - res = htonl(NFS4ERR_NOMATCHING_LAYOUT);
> + res = cpu_to_be32(NFS4ERR_NOMATCHING_LAYOUT);
> do {
> struct nfs_client *prev = clp;
> num_client++;
> - inode = nfs_layoutrecall_find_inode(clp, args);
> - if (inode != NULL) {
> - if (PNFS_LD(&NFS_I(inode)->layout)->id ==
> - args->cbl_layout_type) {
> - /* Set up a helper thread to actually
> - * return the delegation */
> - res = pnfs_async_return_layout(clp, inode, args);
> - if (res != 0)
> - res = htonl(NFS4ERR_RESOURCE);
> - break;
> + /* the callback must come from the MDS personality */
> + if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
> + goto loop;
> + if (args->cbl_recall_type == RETURN_FILE) {
> + inode = nfs_layoutrecall_find_inode(clp, args);
> + if (inode != NULL) {
> + status = pnfs_async_return_layout(clp, inode,
> + args);
> + if (status == -EAGAIN)
> + res = cpu_to_be32(NFS4ERR_DELAY);
what about other errors?
> + iput(inode);
> }
> + } else { /* _ALL or _FSID */
> + /* we need the inode to get the nfs_server struct */
> + inode = nfs_layoutrecall_find_inode(clp, args);
> + if (!inode)
> + goto loop;
> + status = pnfs_async_return_layout(clp, inode, args);
> + if (status == -EAGAIN)
> + res = cpu_to_be32(NFS4ERR_DELAY);
ditto
> iput(inode);
> }
> +loop:
> clp = nfs_find_client_next(prev);
> nfs_put_client(prev);
> } while (clp != NULL);
> diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
> index ebc9b3b..2f7974b 100644
> --- a/fs/nfs/nfs4_fs.h
> +++ b/fs/nfs/nfs4_fs.h
> @@ -47,6 +47,7 @@ enum nfs4_client_state {
> NFS4CLNT_SESSION_RESET,
> NFS4CLNT_SESSION_DRAINING,
> NFS4CLNT_RECALL_SLOT,
> + NFS4CLNT_LAYOUT_RECALL,
> };
>
> /*
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index d0b45bf..2006926 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -709,6 +709,8 @@ return_layout(struct inode *ino, struct nfs4_pnfs_layout_segment *range,
>
> dprintk("--> %s\n", __func__);
>
> + BUG_ON(type != RETURN_FILE);
> +
> lrp = kzalloc(sizeof(*lrp), GFP_KERNEL);
> if (lrp == NULL) {
> if (lo && (type == RETURN_FILE))
> @@ -745,13 +747,11 @@ _pnfs_return_layout(struct inode *ino, struct nfs4_pnfs_layout_segment *range,
>
> dprintk("--> %s type %d\n", __func__, type);
>
> - if (range)
> - arg = *range;
> - else {
> - arg.iomode = IOMODE_ANY;
> - arg.offset = 0;
> - arg.length = NFS4_MAX_UINT64;
> - }
> +
> + arg.iomode = range ? range->iomode : IOMODE_ANY;
> + arg.offset = 0;
> + arg.length = NFS4_MAX_UINT64;
> +
> if (type == RETURN_FILE) {
> lo = get_lock_current_layout(nfsi);
> if (lo && !has_layout_to_return(lo, &arg)) {
> @@ -760,11 +760,7 @@ _pnfs_return_layout(struct inode *ino, struct nfs4_pnfs_layout_segment *range,
> }
> if (!lo) {
> dprintk("%s: no layout segments to return\n", __func__);
> - /* must send the LAYOUTRETURN in response to recall */
> - if (stateid)
> - goto send_return;
> - else
> - goto out;
> + goto out;
> }
>
> /* unlock w/o put rebalanced by eventual call to
> @@ -773,12 +769,23 @@ _pnfs_return_layout(struct inode *ino, struct nfs4_pnfs_layout_segment *range,
> unlock_current_layout(nfsi);
>
> if (pnfs_return_layout_barrier(nfsi, &arg)) {
> + if (stateid) { /* callback */
> + status = -EAGAIN;
> + lock_current_layout(nfsi);
> + put_unlock_current_layout(lo);
> + goto out;
> + }
> dprintk("%s: waiting\n", __func__);
> wait_event(nfsi->lo_waitq,
> - !pnfs_return_layout_barrier(nfsi, &arg));
> + !pnfs_return_layout_barrier(nfsi, &arg));
> }
>
> if (layoutcommit_needed(nfsi)) {
> + if (stateid && !wait) { /* callback */
> + dprintk("%s: layoutcommit pending\n", __func__);
> + status = -EAGAIN;
> + goto out;
> + }
> status = pnfs_layoutcommit_inode(ino, wait);
> if (status) {
> dprintk("%s: layoutcommit failed, status=%d. "
> @@ -787,9 +794,13 @@ _pnfs_return_layout(struct inode *ino, struct nfs4_pnfs_layout_segment *range,
> status = 0;
> }
> }
> +
> + if (stateid && wait)
> + status = return_layout(ino, &arg, stateid, type,
> + lo, wait);
> + else
> + pnfs_layout_release(lo, &arg);
> }
> -send_return:
> - status = return_layout(ino, &arg, stateid, type, lo, wait);
> out:
> dprintk("<-- %s status: %d\n", __func__, status);
> return status;
> @@ -1044,7 +1055,7 @@ pnfs_update_layout(struct inode *ino,
> struct nfs4_pnfs_layout_segment arg = {
> .iomode = iomode,
> .offset = 0,
> - .length = ~0
> + .length = NFS4_MAX_UINT64,
why do you have to ask for whole file layouts?
Isn't it enough to always return the whole layout
but potentially having more than one layout segment?
Benny
> };
> struct nfs_inode *nfsi = NFS_I(ino);
> struct pnfs_layout_type *lo;
> @@ -1063,31 +1074,12 @@ pnfs_update_layout(struct inode *ino,
> /* Check to see if the layout for the given range already exists */
> lseg = pnfs_has_layout(lo, &arg, take_ref, !take_ref);
> if (lseg && !lseg->valid) {
> - unlock_current_layout(nfsi);
> if (take_ref)
> put_lseg(lseg);
> - for (;;) {
> - prepare_to_wait(&nfsi->lo_waitq, &__wait,
> - TASK_KILLABLE);
> - lock_current_layout(nfsi);
> - lseg = pnfs_has_layout(lo, &arg, take_ref, !take_ref);
> - if (!lseg || lseg->valid)
> - break;
> - dprintk("%s: invalid lseg %p ref %d\n", __func__,
> - lseg, atomic_read(&lseg->kref.refcount)-1);
> - if (take_ref)
> - put_lseg(lseg);
> - if (signal_pending(current)) {
> - lseg = NULL;
> - result = -ERESTARTSYS;
> - break;
> - }
> - unlock_current_layout(nfsi);
> - schedule();
> - }
> - finish_wait(&nfsi->lo_waitq, &__wait);
> - if (result)
> - goto out_put;
> +
> + /* someone is cleaning the layout */
> + result = -EAGAIN;
> + goto out_put;
> }
>
> if (lseg) {
--
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