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authorFred Isaman2011-01-06 11:36:25 +0000
committerTrond Myklebust2011-01-06 14:46:31 -0500
commitcf7d63f1f9895713551df2e6d18b006f8af26e91 (patch)
treefc3dbfc12332878a832c11b5ae47ff259bb1bc32 /fs/nfs
parentc31663d4a1fac5ce1954d656cbcf80eb883b814a (diff)
pnfs: serialize LAYOUTGET(openstateid)
We shouldn't send a LAYOUTGET(openstateid) unless all outstanding RPCs using the previous stateid are completed. This requires choosing the stateid to encode earlier, so we can abort if one is not available (we want to use the open stateid, but a LAYOUTGET is already out using it), and adding a count of the number of outstanding rpc calls using layout state (which for now consist solely of LAYOUTGETs). Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/nfs4proc.c7
-rw-r--r--fs/nfs/nfs4xdr.c5
-rw-r--r--fs/nfs/pnfs.c24
-rw-r--r--fs/nfs/pnfs.h1
4 files changed, 27 insertions, 10 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 5bee453d36d6..a3549ce72ab2 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5304,6 +5304,12 @@ nfs4_layoutget_prepare(struct rpc_task *task, void *calldata)
if (nfs4_setup_sequence(server, &lgp->args.seq_args,
&lgp->res.seq_res, 0, task))
return;
+ if (pnfs_choose_layoutget_stateid(&lgp->args.stateid,
+ NFS_I(lgp->args.inode)->layout,
+ lgp->args.ctx->state)) {
+ rpc_exit(task, NFS4_OK);
+ return;
+ }
rpc_call_start(task);
}
@@ -5338,7 +5344,6 @@ static void nfs4_layoutget_release(void *calldata)
struct nfs4_layoutget *lgp = calldata;
dprintk("--> %s\n", __func__);
- put_layout_hdr(lgp->args.inode);
if (lgp->res.layout.buf != NULL)
free_page((unsigned long) lgp->res.layout.buf);
put_nfs_open_context(lgp->args.ctx);
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 4e28242360d6..3cbdd0c80a2d 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1787,7 +1787,6 @@ encode_layoutget(struct xdr_stream *xdr,
const struct nfs4_layoutget_args *args,
struct compound_hdr *hdr)
{
- nfs4_stateid stateid;
__be32 *p;
p = reserve_space(xdr, 44 + NFS4_STATEID_SIZE);
@@ -1798,9 +1797,7 @@ encode_layoutget(struct xdr_stream *xdr,
p = xdr_encode_hyper(p, args->range.offset);
p = xdr_encode_hyper(p, args->range.length);
p = xdr_encode_hyper(p, args->minlength);
- pnfs_choose_layoutget_stateid(&stateid, NFS_I(args->inode)->layout,
- args->ctx->state);
- p = xdr_encode_opaque_fixed(p, &stateid.data, NFS4_STATEID_SIZE);
+ p = xdr_encode_opaque_fixed(p, &args->stateid.data, NFS4_STATEID_SIZE);
*p = cpu_to_be32(args->maxcount);
dprintk("%s: 1st type:0x%x iomode:%d off:%lu len:%lu mc:%d\n",
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 212cbc22c59d..59ed68bf79fa 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -371,6 +371,14 @@ pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
memcpy(&lo->plh_stateid, &new->stateid, sizeof(new->stateid));
}
+/* lget is set to 1 if called from inside send_layoutget call chain */
+static bool
+pnfs_layoutgets_blocked(struct pnfs_layout_hdr *lo, int lget)
+{
+ return (list_empty(&lo->plh_segs) &&
+ (atomic_read(&lo->plh_outstanding) > lget));
+}
+
int
pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
struct nfs4_state *open_state)
@@ -379,7 +387,9 @@ pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
dprintk("--> %s\n", __func__);
spin_lock(&lo->plh_inode->i_lock);
- if (list_empty(&lo->plh_segs)) {
+ if (pnfs_layoutgets_blocked(lo, 1)) {
+ status = -EAGAIN;
+ } else if (list_empty(&lo->plh_segs)) {
int seq;
do {
@@ -414,10 +424,8 @@ send_layoutget(struct pnfs_layout_hdr *lo,
BUG_ON(ctx == NULL);
lgp = kzalloc(sizeof(*lgp), GFP_KERNEL);
- if (lgp == NULL) {
- put_layout_hdr(lo->plh_inode);
+ if (lgp == NULL)
return NULL;
- }
lgp->args.minlength = NFS4_MAX_UINT64;
lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
lgp->args.range.iomode = iomode;
@@ -613,10 +621,16 @@ pnfs_update_layout(struct inode *ino,
if (test_bit(lo_fail_bit(iomode), &nfsi->layout->plh_flags))
goto out_unlock;
- get_layout_hdr_locked(lo); /* Matched in nfs4_layoutget_release */
+ if (pnfs_layoutgets_blocked(lo, 0))
+ goto out_unlock;
+ atomic_inc(&lo->plh_outstanding);
+
+ get_layout_hdr_locked(lo);
spin_unlock(&ino->i_lock);
lseg = send_layoutget(lo, ctx, iomode);
+ atomic_dec(&lo->plh_outstanding);
+ put_layout_hdr(ino);
out:
dprintk("%s end, state 0x%lx lseg %p\n", __func__,
nfsi->layout->plh_flags, lseg);
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 787253e6fca3..698380da24cc 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -69,6 +69,7 @@ struct pnfs_layout_hdr {
struct list_head plh_layouts; /* other client layouts */
struct list_head plh_segs; /* layout segments list */
nfs4_stateid plh_stateid;
+ atomic_t plh_outstanding; /* number of RPCs out */
unsigned long plh_flags;
struct inode *plh_inode;
};