pnfs: add CB_LAYOUTRECALL handling

This is the heart of the wave 2 submission.  Add the code to trigger
drain and forget of any afected layouts.  In addition, we set a
"barrier", below which any LAYOUTGET reply is ignored.  This is to
compensate for the fact that we do not wait for outstanding LAYOUTGETs
to complete as per section 12.5.5.2.1 of RFC 5661.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 118 insertions, 1 deletions

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index c1bb157e94bd..6619c05b55a0 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -12,6 +12,7 @@
 #include "callback.h"
 #include "delegation.h"
 #include "internal.h"
+#include "pnfs.h"
 
 #ifdef NFS_DEBUG
 #define NFSDBG_FACILITY NFSDBG_CALLBACK
@@ -107,10 +108,126 @@ int nfs4_validate_delegation_stateid(struct nfs_delegation *delegation, const nf
 
 #if defined(CONFIG_NFS_V4_1)
 
+static u32 initiate_file_draining(struct nfs_client *clp,
+                                  struct cb_layoutrecallargs *args)
+{
+        struct pnfs_layout_hdr *lo;
+        struct inode *ino;
+        bool found = false;
+        u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
+        LIST_HEAD(free_me_list);
+
+        spin_lock(&clp->cl_lock);
+        list_for_each_entry(lo, &clp->cl_layouts, plh_layouts) {
+                if (nfs_compare_fh(&args->cbl_fh,
+                                   &NFS_I(lo->plh_inode)->fh))
+                        continue;
+                ino = igrab(lo->plh_inode);
+                if (!ino)
+                        continue;
+                found = true;
+                /* Without this, layout can be freed as soon
+                 * as we release cl_lock.
+                 */
+                get_layout_hdr(lo);
+                break;
+        }
+        spin_unlock(&clp->cl_lock);
+        if (!found)
+                return NFS4ERR_NOMATCHING_LAYOUT;
+
+        spin_lock(&ino->i_lock);
+        if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
+            mark_matching_lsegs_invalid(lo, &free_me_list,
+                                        args->cbl_range.iomode))
+                rv = NFS4ERR_DELAY;
+        else
+                rv = NFS4ERR_NOMATCHING_LAYOUT;
+        pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
+        spin_unlock(&ino->i_lock);
+        pnfs_free_lseg_list(&free_me_list);
+        put_layout_hdr(lo);
+        iput(ino);
+        return rv;
+}
+
+static u32 initiate_bulk_draining(struct nfs_client *clp,
+                                  struct cb_layoutrecallargs *args)
+{
+        struct pnfs_layout_hdr *lo;
+        struct inode *ino;
+        u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
+        struct pnfs_layout_hdr *tmp;
+        LIST_HEAD(recall_list);
+        LIST_HEAD(free_me_list);
+        struct pnfs_layout_range range = {
+                .iomode = IOMODE_ANY,
+                .offset = 0,
+                .length = NFS4_MAX_UINT64,
+        };
+
+        spin_lock(&clp->cl_lock);
+        list_for_each_entry(lo, &clp->cl_layouts, plh_layouts) {
+                if ((args->cbl_recall_type == RETURN_FSID) &&
+                    memcmp(&NFS_SERVER(lo->plh_inode)->fsid,
+                           &args->cbl_fsid, sizeof(struct nfs_fsid)))
+                        continue;
+                if (!igrab(lo->plh_inode))
+                        continue;
+                get_layout_hdr(lo);
+                BUG_ON(!list_empty(&lo->plh_bulk_recall));
+                list_add(&lo->plh_bulk_recall, &recall_list);
+        }
+        spin_unlock(&clp->cl_lock);
+        list_for_each_entry_safe(lo, tmp,
+                                 &recall_list, plh_bulk_recall) {
+                ino = lo->plh_inode;
+                spin_lock(&ino->i_lock);
+                set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
+                if (mark_matching_lsegs_invalid(lo, &free_me_list, range.iomode))
+                        rv = NFS4ERR_DELAY;
+                list_del_init(&lo->plh_bulk_recall);
+                spin_unlock(&ino->i_lock);
+                put_layout_hdr(lo);
+                iput(ino);
+        }
+        pnfs_free_lseg_list(&free_me_list);
+        return rv;
+}
+
+static u32 do_callback_layoutrecall(struct nfs_client *clp,
+                                    struct cb_layoutrecallargs *args)
+{
+        u32 res = NFS4ERR_DELAY;
+
+        dprintk("%s enter, type=%i\n", __func__, args->cbl_recall_type);
+        if (test_and_set_bit(NFS4CLNT_LAYOUTRECALL, &clp->cl_state))
+                goto out;
+        if (args->cbl_recall_type == RETURN_FILE)
+                res = initiate_file_draining(clp, args);
+        else
+                res = initiate_bulk_draining(clp, args);
+        clear_bit(NFS4CLNT_LAYOUTRECALL, &clp->cl_state);
+out:
+        dprintk("%s returning %i\n", __func__, res);
+        return res;
+
+}
+
 __be32 nfs4_callback_layoutrecall(struct cb_layoutrecallargs *args,
                                   void *dummy, struct cb_process_state *cps)
 {
-        return cpu_to_be32(NFS4ERR_NOTSUPP); /* STUB */
+        u32 res;
+
+        dprintk("%s: -->\n", __func__);
+
+        if (cps->clp)
+                res = do_callback_layoutrecall(cps->clp, args);
+        else
+                res = NFS4ERR_OP_NOT_IN_SESSION;
+
+        dprintk("%s: exit with status = %d\n", __func__, res);
+        return cpu_to_be32(res);
 }
 
 int nfs41_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid)