pnfs: add pnfs_report_layoutstat helper function

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>

3 files changed, 56 insertions, 0 deletions

diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index a0530418255f..ee0248340a42 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -198,6 +198,10 @@ static void
 nfs42_layoutstat_release(void *calldata)
 {
         struct nfs42_layoutstat_data *data = calldata;
+        struct nfs_server *nfss = NFS_SERVER(data->args.inode);
+
+        if (nfss->pnfs_curr_ld->cleanup_layoutstats)
+                nfss->pnfs_curr_ld->cleanup_layoutstats(data);
 
         pnfs_put_layout_hdr(NFS_I(data->args.inode)->layout);
         nfs_iput_and_deactive(data->inode);
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index d47c188682b1..6279cff7df74 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -35,6 +35,7 @@
 #include "iostat.h"
 #include "nfs4trace.h"
 #include "delegation.h"
+#include "nfs42.h"
 
 #define NFSDBG_FACILITY         NFSDBG_PNFS
 #define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
@@ -2250,3 +2251,51 @@ struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
         }
         return thp;
 }
+
+int
+pnfs_report_layoutstat(struct inode *inode)
+{
+        struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
+        struct nfs_server *server = NFS_SERVER(inode);
+        struct nfs42_layoutstat_data *data;
+        struct pnfs_layout_hdr *hdr;
+        int status = 0;
+
+        if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
+                goto out;
+
+        spin_lock(&inode->i_lock);
+        if (!NFS_I(inode)->layout) {
+                spin_unlock(&inode->i_lock);
+                goto out;
+        }
+        hdr = NFS_I(inode)->layout;
+        pnfs_get_layout_hdr(hdr);
+        spin_unlock(&inode->i_lock);
+
+        data = kzalloc(sizeof(*data), GFP_KERNEL);
+        if (!data) {
+                status = -ENOMEM;
+                goto out_put;
+        }
+
+        data->args.fh = NFS_FH(inode);
+        data->args.inode = inode;
+        nfs4_stateid_copy(&data->args.stateid, &hdr->plh_stateid);
+        status = ld->prepare_layoutstats(&data->args);
+        if (status)
+                goto out_free;
+
+        status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
+
+out:
+        dprintk("%s returns %d\n", __func__, status);
+        return status;
+
+out_free:
+        kfree(data);
+out_put:
+        pnfs_put_layout_hdr(hdr);
+        goto out;
+}
+EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 1e6308f82fc3..0a4723945db2 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -178,6 +178,8 @@ struct pnfs_layoutdriver_type {
         void (*encode_layoutcommit) (struct pnfs_layout_hdr *lo,
                                      struct xdr_stream *xdr,
                                      const struct nfs4_layoutcommit_args *args);
+        int (*prepare_layoutstats) (struct nfs42_layoutstat_args *args);
+        void (*cleanup_layoutstats) (struct nfs42_layoutstat_data *data);
 };
 
 struct pnfs_layout_hdr {
@@ -290,6 +292,7 @@ int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *);
 struct nfs4_threshold *pnfs_mdsthreshold_alloc(void);
 void pnfs_error_mark_layout_for_return(struct inode *inode,
                                        struct pnfs_layout_segment *lseg);
+int pnfs_report_layoutstat(struct inode *inode);
 
 /* nfs4_deviceid_flags */
 enum {