pnfs: Add barrier to prevent lgopen using LAYOUTGET during recall
Since the LAYOUTGET on OPEN can be sent without prior inode information,
existing methods to prevent LAYOUTGET from being sent while processing
CB_LAYOUTRECALL don't work. Track if a recall occurred while LAYOUTGET
was being sent, and if so ignore the results.
Signed-off-by: Fred Isaman <fred.isaman@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 3dfe9fa..a29fdea 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1017,6 +1017,7 @@ pnfs_alloc_init_layoutget_args(struct inode *ino,
nfs4_stateid_copy(&lgp->args.stateid, stateid);
lgp->gfp_flags = gfp_flags;
lgp->cred = get_rpccred(ctx->cred);
+ lgp->callback_count = raw_seqcount_begin(&server->nfs_client->cl_callback_count);
return lgp;
}
@@ -2101,6 +2102,7 @@ void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
{
struct pnfs_layout_hdr *lo;
struct pnfs_layout_segment *lseg;
+ struct nfs_server *srv = NFS_SERVER(ino);
u32 iomode;
if (!lgp)
@@ -2116,7 +2118,7 @@ void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
/* FIXME - Any error not listed above permanently
* halts lgopen attempts.
*/
- NFS_SERVER(ino)->caps &= ~NFS_CAP_LGOPEN;
+ srv->caps &= ~NFS_CAP_LGOPEN;
}
return;
}
@@ -2129,6 +2131,9 @@ void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
lo = NFS_I(lgp->args.inode)->layout;
pnfs_get_layout_hdr(lo);
+ if (read_seqcount_retry(&srv->nfs_client->cl_callback_count,
+ lgp->callback_count))
+ goto out;
lseg = pnfs_layout_process(lgp);
atomic_dec(&lo->plh_outstanding);
if (IS_ERR(lseg)) {
@@ -2139,6 +2144,7 @@ void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
pnfs_put_lseg(lseg);
}
+out:
pnfs_clear_first_layoutget(lo);
pnfs_put_layout_hdr(lo);
}