1 files changed, 71 insertions, 0 deletions

diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index 4215278c9c76..cd999af504d9 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -20,6 +20,7 @@
 #include "../nfs4trace.h"
 #include "../iostat.h"
 #include "../nfs.h"
+#include "../nfs42.h"
 
 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
 
@@ -1659,6 +1660,75 @@ out:
         dprintk("%s: Return\n", __func__);
 }
 
+static bool
+ff_layout_mirror_prepare_stats(struct nfs42_layoutstat_args *args,
+                               struct pnfs_layout_segment *pls,
+                               int *dev_count, int dev_limit)
+{
+        struct nfs4_ff_layout_mirror *mirror;
+        struct nfs4_deviceid_node *dev;
+        struct nfs42_layoutstat_devinfo *devinfo;
+        int i;
+
+        for (i = 0; i <= FF_LAYOUT_MIRROR_COUNT(pls); i++) {
+                if (*dev_count >= dev_limit)
+                        break;
+                mirror = FF_LAYOUT_COMP(pls, i);
+                dev = FF_LAYOUT_DEVID_NODE(pls, i);
+                devinfo = &args->devinfo[*dev_count];
+                memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
+                devinfo->offset = pls->pls_range.offset;
+                devinfo->length = pls->pls_range.length;
+                /* well, we don't really know if IO is continuous or not! */
+                devinfo->read_count = mirror->read_stat.io_stat.bytes_completed;
+                devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
+                devinfo->write_count = mirror->write_stat.io_stat.bytes_completed;
+                devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
+                devinfo->layout_type = LAYOUT_FLEX_FILES;
+                devinfo->layoutstats_encode = NULL;
+                devinfo->layout_private = NULL;
+
+                ++(*dev_count);
+        }
+
+        return *dev_count < dev_limit;
+}
+
+static int
+ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
+{
+        struct pnfs_layout_segment *pls;
+        int dev_count = 0;
+
+        spin_lock(&args->inode->i_lock);
+        list_for_each_entry(pls, &NFS_I(args->inode)->layout->plh_segs, pls_list) {
+                dev_count += FF_LAYOUT_MIRROR_COUNT(pls);
+        }
+        spin_unlock(&args->inode->i_lock);
+        /* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
+        if (dev_count > PNFS_LAYOUTSTATS_MAXDEV) {
+                dprintk("%s: truncating devinfo to limit (%d:%d)\n",
+                        __func__, dev_count, PNFS_LAYOUTSTATS_MAXDEV);
+                dev_count = PNFS_LAYOUTSTATS_MAXDEV;
+        }
+        args->devinfo = kmalloc(dev_count * sizeof(*args->devinfo), GFP_KERNEL);
+        if (!args->devinfo)
+                return -ENOMEM;
+
+        dev_count = 0;
+        spin_lock(&args->inode->i_lock);
+        list_for_each_entry(pls, &NFS_I(args->inode)->layout->plh_segs, pls_list) {
+                if (!ff_layout_mirror_prepare_stats(args, pls, &dev_count,
+                                                    PNFS_LAYOUTSTATS_MAXDEV)) {
+                        break;
+                }
+        }
+        spin_unlock(&args->inode->i_lock);
+        args->num_dev = dev_count;
+
+        return 0;
+}
+
 static struct pnfs_layoutdriver_type flexfilelayout_type = {
         .id                     = LAYOUT_FLEX_FILES,
         .name                   = "LAYOUT_FLEX_FILES",
@@ -1681,6 +1751,7 @@ static struct pnfs_layoutdriver_type flexfilelayout_type = {
         .alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
         .encode_layoutreturn    = ff_layout_encode_layoutreturn,
         .sync                   = pnfs_nfs_generic_sync,
+        .prepare_layoutstats    = ff_layout_prepare_layoutstats,
 };
 
 static int __init nfs4flexfilelayout_init(void)