nfsd: add SCSI layout support
This is a simple extension to the block layout driver to use SCSI
persistent reservations for access control and fencing, as well as
SCSI VPD pages for device identification.
For this we need to pass the nfs4_client to the proc_getdeviceinfo method
to generate the reservation key, and add a new fence_client method
to allow for fence actions in the layout driver.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
index 4e4def7..825c7bc 100644
--- a/fs/nfsd/nfs4layouts.c
+++ b/fs/nfsd/nfs4layouts.c
@@ -1,6 +1,7 @@
/*
* Copyright (c) 2014 Christoph Hellwig.
*/
+#include <linux/blkdev.h>
#include <linux/kmod.h>
#include <linux/file.h>
#include <linux/jhash.h>
@@ -29,6 +30,9 @@
#ifdef CONFIG_NFSD_BLOCKLAYOUT
[LAYOUT_BLOCK_VOLUME] = &bl_layout_ops,
#endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+ [LAYOUT_SCSI] = &scsi_layout_ops,
+#endif
};
/* pNFS device ID to export fsid mapping */
@@ -123,12 +127,24 @@
if (!(exp->ex_flags & NFSEXP_PNFS))
return;
+ /*
+ * Check if the file system supports exporting a block-like layout.
+ * If the block device supports reservations prefer the SCSI layout,
+ * otherwise advertise the block layout.
+ */
#ifdef CONFIG_NFSD_BLOCKLAYOUT
if (sb->s_export_op->get_uuid &&
sb->s_export_op->map_blocks &&
sb->s_export_op->commit_blocks)
exp->ex_layout_type = LAYOUT_BLOCK_VOLUME;
#endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+ /* overwrite block layout selection if needed */
+ if (sb->s_export_op->map_blocks &&
+ sb->s_export_op->commit_blocks &&
+ sb->s_bdev && sb->s_bdev->bd_disk->fops->pr_ops)
+ exp->ex_layout_type = LAYOUT_SCSI;
+#endif
}
static void
@@ -594,8 +610,6 @@
rpc_ntop((struct sockaddr *)&clp->cl_addr, addr_str, sizeof(addr_str));
- trace_layout_recall_fail(&ls->ls_stid.sc_stateid);
-
printk(KERN_WARNING
"nfsd: client %s failed to respond to layout recall. "
" Fencing..\n", addr_str);
@@ -630,6 +644,7 @@
container_of(cb, struct nfs4_layout_stateid, ls_recall);
struct nfsd_net *nn;
ktime_t now, cutoff;
+ const struct nfsd4_layout_ops *ops;
LIST_HEAD(reaplist);
@@ -665,7 +680,13 @@
/*
* Unknown error or non-responding client, we'll need to fence.
*/
- nfsd4_cb_layout_fail(ls);
+ trace_layout_recall_fail(&ls->ls_stid.sc_stateid);
+
+ ops = nfsd4_layout_ops[ls->ls_layout_type];
+ if (ops->fence_client)
+ ops->fence_client(ls);
+ else
+ nfsd4_cb_layout_fail(ls);
return -1;
}
}