nfs42: serialize LAYOUTSTATS calls of the same file
There is no need to report concurrently.
Reviewed-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 6279cff..5b52243 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -2257,6 +2257,7 @@
{
struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
struct nfs_server *server = NFS_SERVER(inode);
+ struct nfs_inode *nfsi = NFS_I(inode);
struct nfs42_layoutstat_data *data;
struct pnfs_layout_hdr *hdr;
int status = 0;
@@ -2264,6 +2265,9 @@
if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
goto out;
+ if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
+ goto out;
+
spin_lock(&inode->i_lock);
if (!NFS_I(inode)->layout) {
spin_unlock(&inode->i_lock);
@@ -2296,6 +2300,9 @@
kfree(data);
out_put:
pnfs_put_layout_hdr(hdr);
+ smp_mb__before_atomic();
+ clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
+ smp_mb__after_atomic();
goto out;
}
EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
