pNFS: Don't allocate more pages than we need to fit a layoutget response
For the 'files' and 'flexfiles' layout types, we do not expect the reply
to be any larger than 4k. The block and scsi layout types are a little more
greedy, so we keep allocating the maximum response size for now.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
index d175724..61f46fa 100644
--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -1164,6 +1164,7 @@
.id = LAYOUT_NFSV4_1_FILES,
.name = "LAYOUT_NFSV4_1_FILES",
.owner = THIS_MODULE,
+ .max_layoutget_response = 4096, /* 1 page or so... */
.alloc_layout_hdr = filelayout_alloc_layout_hdr,
.free_layout_hdr = filelayout_free_layout_hdr,
.alloc_lseg = filelayout_alloc_lseg,
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index cae4333..86bcba4 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -2356,6 +2356,7 @@
.name = "LAYOUT_FLEX_FILES",
.owner = THIS_MODULE,
.flags = PNFS_LAYOUTGET_ON_OPEN,
+ .max_layoutget_response = 4096, /* 1 page or so... */
.set_layoutdriver = ff_layout_set_layoutdriver,
.alloc_layout_hdr = ff_layout_alloc_layout_hdr,
.free_layout_hdr = ff_layout_free_layout_hdr,
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 6b5b2d3..c5672c0 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -991,6 +991,7 @@
gfp_t gfp_flags)
{
struct nfs_server *server = pnfs_find_server(ino, ctx);
+ size_t max_reply_sz = server->pnfs_curr_ld->max_layoutget_response;
size_t max_pages = max_response_pages(server);
struct nfs4_layoutget *lgp;
@@ -1000,6 +1001,12 @@
if (lgp == NULL)
return NULL;
+ if (max_reply_sz) {
+ size_t npages = (max_reply_sz + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ if (npages < max_pages)
+ max_pages = npages;
+ }
+
lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
if (!lgp->args.layout.pages) {
kfree(lgp);
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index ece367e..e2e9fcd 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -125,6 +125,7 @@
struct module *owner;
unsigned flags;
unsigned max_deviceinfo_size;
+ unsigned max_layoutget_response;
int (*set_layoutdriver) (struct nfs_server *, const struct nfs_fh *);
int (*clear_layoutdriver) (struct nfs_server *);