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/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 @@ pnfs_alloc_init_layoutget_args(struct inode *ino,
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 @@ pnfs_alloc_init_layoutget_args(struct inode *ino,
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);
