NFS: client needs to maintain list of inodes with active layouts
In particular, server reboot will invalidate all layouts.
Note that in order to have an active layout, we must get a successful response
from the server. To avoid adding that machinery, this patch just includes a
stub that fakes up a successful return. Since the layout is never referenced
for io, this is not a problem.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Dean Hildebrand <dhildebz@umich.edu>
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index c0cd954..891a0c3 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -28,6 +28,7 @@
*/
#include <linux/nfs_fs.h>
+#include "internal.h"
#include "pnfs.h"
#define NFSDBG_FACILITY NFSDBG_PNFS
@@ -183,38 +184,189 @@
lo->refcount--;
if (!lo->refcount) {
dprintk("%s: freeing layout cache %p\n", __func__, lo);
+ BUG_ON(!list_empty(&lo->layouts));
NFS_I(lo->inode)->layout = NULL;
kfree(lo);
}
}
+static void
+put_layout_hdr(struct inode *inode)
+{
+ spin_lock(&inode->i_lock);
+ put_layout_hdr_locked(NFS_I(inode)->layout);
+ spin_unlock(&inode->i_lock);
+}
+
+static void
+init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg)
+{
+ INIT_LIST_HEAD(&lseg->fi_list);
+ kref_init(&lseg->kref);
+ lseg->layout = lo;
+}
+
+/* Called without i_lock held, as the free_lseg call may sleep */
+static void
+destroy_lseg(struct kref *kref)
+{
+ struct pnfs_layout_segment *lseg =
+ container_of(kref, struct pnfs_layout_segment, kref);
+ struct inode *ino = lseg->layout->inode;
+
+ dprintk("--> %s\n", __func__);
+ kfree(lseg);
+ /* Matched by get_layout_hdr_locked in pnfs_insert_layout */
+ put_layout_hdr(ino);
+}
+
+static void
+put_lseg(struct pnfs_layout_segment *lseg)
+{
+ if (!lseg)
+ return;
+
+ dprintk("%s: lseg %p ref %d\n", __func__, lseg,
+ atomic_read(&lseg->kref.refcount));
+ kref_put(&lseg->kref, destroy_lseg);
+}
+
+static void
+pnfs_clear_lseg_list(struct pnfs_layout_hdr *lo, struct list_head *tmp_list)
+{
+ struct pnfs_layout_segment *lseg, *next;
+ struct nfs_client *clp;
+
+ dprintk("%s:Begin lo %p\n", __func__, lo);
+
+ assert_spin_locked(&lo->inode->i_lock);
+ list_for_each_entry_safe(lseg, next, &lo->segs, fi_list) {
+ dprintk("%s: freeing lseg %p\n", __func__, lseg);
+ list_move(&lseg->fi_list, tmp_list);
+ }
+ clp = NFS_SERVER(lo->inode)->nfs_client;
+ spin_lock(&clp->cl_lock);
+ /* List does not take a reference, so no need for put here */
+ list_del_init(&lo->layouts);
+ spin_unlock(&clp->cl_lock);
+
+ dprintk("%s:Return\n", __func__);
+}
+
+static void
+pnfs_free_lseg_list(struct list_head *tmp_list)
+{
+ struct pnfs_layout_segment *lseg;
+
+ while (!list_empty(tmp_list)) {
+ lseg = list_entry(tmp_list->next, struct pnfs_layout_segment,
+ fi_list);
+ dprintk("%s calling put_lseg on %p\n", __func__, lseg);
+ list_del(&lseg->fi_list);
+ put_lseg(lseg);
+ }
+}
+
void
pnfs_destroy_layout(struct nfs_inode *nfsi)
{
struct pnfs_layout_hdr *lo;
+ LIST_HEAD(tmp_list);
spin_lock(&nfsi->vfs_inode.i_lock);
lo = nfsi->layout;
if (lo) {
+ pnfs_clear_lseg_list(lo, &tmp_list);
/* Matched by refcount set to 1 in alloc_init_layout_hdr */
put_layout_hdr_locked(lo);
}
spin_unlock(&nfsi->vfs_inode.i_lock);
+ pnfs_free_lseg_list(&tmp_list);
}
-/* STUB - pretend LAYOUTGET to server failed */
+/*
+ * Called by the state manger to remove all layouts established under an
+ * expired lease.
+ */
+void
+pnfs_destroy_all_layouts(struct nfs_client *clp)
+{
+ struct pnfs_layout_hdr *lo;
+ LIST_HEAD(tmp_list);
+
+ spin_lock(&clp->cl_lock);
+ list_splice_init(&clp->cl_layouts, &tmp_list);
+ spin_unlock(&clp->cl_lock);
+
+ while (!list_empty(&tmp_list)) {
+ lo = list_entry(tmp_list.next, struct pnfs_layout_hdr,
+ layouts);
+ dprintk("%s freeing layout for inode %lu\n", __func__,
+ lo->inode->i_ino);
+ pnfs_destroy_layout(NFS_I(lo->inode));
+ }
+}
+
+static void pnfs_insert_layout(struct pnfs_layout_hdr *lo,
+ struct pnfs_layout_segment *lseg);
+
+/* Get layout from server. */
static struct pnfs_layout_segment *
send_layoutget(struct pnfs_layout_hdr *lo,
struct nfs_open_context *ctx,
u32 iomode)
{
struct inode *ino = lo->inode;
+ struct pnfs_layout_segment *lseg;
- set_bit(lo_fail_bit(iomode), &lo->state);
+ /* Lets pretend we sent LAYOUTGET and got a response */
+ lseg = kzalloc(sizeof(*lseg), GFP_KERNEL);
+ if (!lseg) {
+ set_bit(lo_fail_bit(iomode), &lo->state);
+ spin_lock(&ino->i_lock);
+ put_layout_hdr_locked(lo);
+ spin_unlock(&ino->i_lock);
+ return NULL;
+ }
+ init_lseg(lo, lseg);
+ lseg->iomode = IOMODE_RW;
spin_lock(&ino->i_lock);
+ pnfs_insert_layout(lo, lseg);
put_layout_hdr_locked(lo);
spin_unlock(&ino->i_lock);
- return NULL;
+ return lseg;
+}
+
+static void
+pnfs_insert_layout(struct pnfs_layout_hdr *lo,
+ struct pnfs_layout_segment *lseg)
+{
+ dprintk("%s:Begin\n", __func__);
+
+ assert_spin_locked(&lo->inode->i_lock);
+ if (list_empty(&lo->segs)) {
+ struct nfs_client *clp = NFS_SERVER(lo->inode)->nfs_client;
+
+ spin_lock(&clp->cl_lock);
+ BUG_ON(!list_empty(&lo->layouts));
+ list_add_tail(&lo->layouts, &clp->cl_layouts);
+ spin_unlock(&clp->cl_lock);
+ }
+ get_layout_hdr_locked(lo);
+ /* STUB - add the constructed lseg if necessary */
+ if (list_empty(&lo->segs)) {
+ list_add_tail(&lseg->fi_list, &lo->segs);
+ dprintk("%s: inserted lseg %p iomode %d at tail\n",
+ __func__, lseg, lseg->iomode);
+ } else {
+ /* There is no harm for the moment in calling this
+ * with the lock held, and the call will be removed
+ * with the STUB.
+ */
+ put_lseg(lseg);
+ }
+
+ dprintk("%s:Return\n", __func__);
}
static struct pnfs_layout_hdr *
@@ -226,6 +378,8 @@
if (!lo)
return NULL;
lo->refcount = 1;
+ INIT_LIST_HEAD(&lo->layouts);
+ INIT_LIST_HEAD(&lo->segs);
lo->inode = ino;
return lo;
}