nfs41: add NFS_LAYOUT_RETRY_LAYOUTGET to layout header flags

Use it to indicate that LD wants to retry layoutget. LD can set
it whenever it wants the common pnfs code to return and retry
pnfs path through a new layout.

The bit gets cleared when client does a new layoutget, when client
closes the file (ROC case), or when kernel needs to evict the inode
(non-ROC case).

Signed-off-by: Peng Tao <tao.peng@primarydata.com>

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 108a619861e50bdb48845af4bdb5340d6384275a..893f6b5afe6a55f74e94e1e7ffd027964a4b0bbc 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -615,6 +615,7 @@ pnfs_destroy_layout(struct nfs_inode *nfsi)
                pnfs_get_layout_hdr(lo);
                pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
                pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
+               pnfs_clear_retry_layoutget(lo);
                spin_unlock(&nfsi->vfs_inode.i_lock);
                pnfs_free_lseg_list(&tmp_list);
                pnfs_put_layout_hdr(lo);
@@ -1066,6 +1067,7 @@ bool pnfs_roc(struct inode *ino)
        if (!lo || !test_and_clear_bit(NFS_LAYOUT_ROC, &lo->plh_flags) ||
            test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
                goto out_nolayout;
+       pnfs_clear_retry_layoutget(lo);
        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);
@@ -1491,6 +1493,7 @@ lookup_again:
                arg.length = PAGE_CACHE_ALIGN(arg.length);
 
        lseg = send_layoutget(lo, ctx, &arg, gfp_flags);
+       pnfs_clear_retry_layoutget(lo);
        atomic_dec(&lo->plh_outstanding);
 out_put_layout_hdr:
        if (first) {

diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 080bf90498d4ac2ffbcd9864bd19c784b436fbd6..fed6ae067acba584bdecfd03e657aaa1aee537b8 100644 (file)
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -99,6 +99,7 @@ enum {
        NFS_LAYOUT_RETURN_BEFORE_CLOSE, /* Return this layout before close */
        NFS_LAYOUT_INVALID_STID,        /* layout stateid id is invalid */
        NFS_LAYOUT_FIRST_LAYOUTGET,     /* Serialize first layoutget */
+       NFS_LAYOUT_RETRY_LAYOUTGET,     /* Retry layoutget */
 };
 
 enum layoutdriver_policy_flags {
@@ -350,6 +351,23 @@ nfs4_get_deviceid(struct nfs4_deviceid_node *d)
        return d;
 }
 
+static inline void pnfs_set_retry_layoutget(struct pnfs_layout_hdr *lo)
+{
+       if (!test_and_set_bit(NFS_LAYOUT_RETRY_LAYOUTGET, &lo->plh_flags))
+               atomic_inc(&lo->plh_refcount);
+}
+
+static inline void pnfs_clear_retry_layoutget(struct pnfs_layout_hdr *lo)
+{
+       if (test_and_clear_bit(NFS_LAYOUT_RETRY_LAYOUTGET, &lo->plh_flags))
+               atomic_dec(&lo->plh_refcount);
+}
+
+static inline bool pnfs_should_retry_layoutget(struct pnfs_layout_hdr *lo)
+{
+       return test_bit(NFS_LAYOUT_RETRY_LAYOUTGET, &lo->plh_flags);
+}
+
 static inline struct pnfs_layout_segment *
 pnfs_get_lseg(struct pnfs_layout_segment *lseg)
 {