NFSv4.1: Optimise layout return-on-close

Optimise the layout return on close code by ensuring that

1) Add a check for whether we hold a layout before taking any spinlocks
2) Only take the spin lock once
3) Use nfs_state->state to speed up open file checks

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 66befb0..0f75b92 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2714,45 +2714,10 @@ static const struct rpc_call_ops nfs4_close_ops = {
        .rpc_release = nfs4_free_closedata,
 };
 
-static bool nfs4_state_has_opener(struct nfs4_state *state)
-{
-       /* first check existing openers */
-       if (test_bit(NFS_O_RDONLY_STATE, &state->flags) != 0 &&
-           state->n_rdonly != 0)
-               return true;
-
-       if (test_bit(NFS_O_WRONLY_STATE, &state->flags) != 0 &&
-           state->n_wronly != 0)
-               return true;
-
-       if (test_bit(NFS_O_RDWR_STATE, &state->flags) != 0 &&
-           state->n_rdwr != 0)
-               return true;
-
-       return false;
-}
-
 static bool nfs4_roc(struct inode *inode)
 {
-       struct nfs_inode *nfsi = NFS_I(inode);
-       struct nfs_open_context *ctx;
-       struct nfs4_state *state;
-
-       spin_lock(&inode->i_lock);
-       list_for_each_entry(ctx, &nfsi->open_files, list) {
-               state = ctx->state;
-               if (state == NULL)
-                       continue;
-               if (nfs4_state_has_opener(state)) {
-                       spin_unlock(&inode->i_lock);
-                       return false;
-               }
-       }
-       spin_unlock(&inode->i_lock);
-
-       if (nfs4_check_delegation(inode, FMODE_READ))
+       if (!nfs_have_layout(inode))
                return false;
-
        return pnfs_roc(inode);
 }
 

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 0a5dda4..4d69076 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -34,6 +34,7 @@
 #include "pnfs.h"
 #include "iostat.h"
 #include "nfs4trace.h"
+#include "delegation.h"
 
 #define NFSDBG_FACILITY                NFSDBG_PNFS
 #define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
@@ -954,30 +955,45 @@ pnfs_commit_and_return_layout(struct inode *inode)
 
 bool pnfs_roc(struct inode *ino)
 {
+       struct nfs_inode *nfsi = NFS_I(ino);
+       struct nfs_open_context *ctx;
+       struct nfs4_state *state;
        struct pnfs_layout_hdr *lo;
        struct pnfs_layout_segment *lseg, *tmp;
        LIST_HEAD(tmp_list);
        bool found = false;
 
        spin_lock(&ino->i_lock);
-       lo = NFS_I(ino)->layout;
+       lo = nfsi->layout;
        if (!lo || !test_and_clear_bit(NFS_LAYOUT_ROC, &lo->plh_flags) ||
            test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
-               goto out_nolayout;
+               goto out_noroc;
+
+       /* Don't return layout if we hold a delegation */
+       if (nfs4_check_delegation(ino, FMODE_READ))
+               goto out_noroc;
+
+       list_for_each_entry(ctx, &nfsi->open_files, list) {
+               state = ctx->state;
+               /* Don't return layout if there is open file state */
+               if (state != NULL && state->state != 0)
+                       goto out_noroc;
+       }
+
        list_for_each_entry_safe(lseg, tmp, &lo->plh_segs, pls_list)
                if (test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
                        mark_lseg_invalid(lseg, &tmp_list);
                        found = true;
                }
        if (!found)
-               goto out_nolayout;
+               goto out_noroc;
        lo->plh_block_lgets++;
        pnfs_get_layout_hdr(lo); /* matched in pnfs_roc_release */
        spin_unlock(&ino->i_lock);
        pnfs_free_lseg_list(&tmp_list);
        return true;
 
-out_nolayout:
+out_noroc:
        spin_unlock(&ino->i_lock);
        return false;
 }

diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 9ae5b76..a98d8fd 100644 (file)
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -275,6 +275,11 @@ void nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node);
 bool nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node);
 void nfs4_deviceid_purge_client(const struct nfs_client *);
 
+static inline bool nfs_have_layout(struct inode *inode)
+{
+       return NFS_I(inode)->layout != NULL;
+}
+
 static inline struct nfs4_deviceid_node *
 nfs4_get_deviceid(struct nfs4_deviceid_node *d)
 {
@@ -427,6 +432,11 @@ static inline void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id)
 #endif /* NFS_DEBUG */
 #else  /* CONFIG_NFS_V4_1 */
 
+static inline bool nfs_have_layout(struct inode *inode)
+{
+       return false;
+}
+
 static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
 {
 }