NFS: Fix handful of compiler warnings in direct.c

This patch fixes a couple of signage issues that were causing an Oops
when running the LTP diotest4 test. get_user_pages() returns a signed
error, hence we need to be careful when comparing with the unsigned
number of pages from data->npages.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 16 insertions, 10 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 345aa5c0f382..6c588ec84d1c 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -122,9 +122,9 @@ ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_
         return -EINVAL;
 }
 
-static void nfs_direct_dirty_pages(struct page **pages, int npages)
+static void nfs_direct_dirty_pages(struct page **pages, unsigned int npages)
 {
-        int i;
+        unsigned int i;
         for (i = 0; i < npages; i++) {
                 struct page *page = pages[i];
                 if (!PageCompound(page))
@@ -132,9 +132,9 @@ static void nfs_direct_dirty_pages(struct page **pages, int npages)
         }
 }
 
-static void nfs_direct_release_pages(struct page **pages, int npages)
+static void nfs_direct_release_pages(struct page **pages, unsigned int npages)
 {
-        int i;
+        unsigned int i;
         for (i = 0; i < npages; i++)
                 page_cache_release(pages[i]);
 }
@@ -279,9 +279,12 @@ static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned lo
                 result = get_user_pages(current, current->mm, user_addr,
                                         data->npages, 1, 0, data->pagevec, NULL);
                 up_read(&current->mm->mmap_sem);
-                if (unlikely(result < data->npages)) {
-                        if (result > 0)
-                                nfs_direct_release_pages(data->pagevec, result);
+                if (result < 0) {
+                        nfs_readdata_release(data);
+                        break;
+                }
+                if ((unsigned)result < data->npages) {
+                        nfs_direct_release_pages(data->pagevec, result);
                         nfs_readdata_release(data);
                         break;
                 }
@@ -610,9 +613,12 @@ static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned l
                 result = get_user_pages(current, current->mm, user_addr,
                                         data->npages, 0, 0, data->pagevec, NULL);
                 up_read(&current->mm->mmap_sem);
-                if (unlikely(result < data->npages)) {
-                        if (result > 0)
-                                nfs_direct_release_pages(data->pagevec, result);
+                if (result < 0) {
+                        nfs_writedata_release(data);
+                        break;
+                }
+                if ((unsigned)result < data->npages) {
+                        nfs_direct_release_pages(data->pagevec, result);
                         nfs_writedata_release(data);
                         break;
                 }