pnfsblock: fix return code confusion

Always return PTR_ERR, not NULL, from nfs4_blk_get_deviceinfo and
nfs4_blk_decode_device.

Check for IS_ERR, not NULL, in bl_set_layoutdriver when calling
nfs4_blk_get_deviceinfo.

Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Cc: stable@kernel.org [3.0]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 20 insertions, 13 deletions

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 9561c8fc8bdb..d2432f0dc40c 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -805,7 +805,7 @@ nfs4_blk_get_deviceinfo(struct nfs_server *server, const struct nfs_fh *fh,
                         struct nfs4_deviceid *d_id)
 {
         struct pnfs_device *dev;
-        struct pnfs_block_dev *rv = NULL;
+        struct pnfs_block_dev *rv;
         u32 max_resp_sz;
         int max_pages;
         struct page **pages = NULL;
@@ -823,18 +823,20 @@ nfs4_blk_get_deviceinfo(struct nfs_server *server, const struct nfs_fh *fh,
         dev = kmalloc(sizeof(*dev), GFP_NOFS);
         if (!dev) {
                 dprintk("%s kmalloc failed\n", __func__);
-                return NULL;
+                return ERR_PTR(-ENOMEM);
         }
 
         pages = kzalloc(max_pages * sizeof(struct page *), GFP_NOFS);
         if (pages == NULL) {
                 kfree(dev);
-                return NULL;
+                return ERR_PTR(-ENOMEM);
         }
         for (i = 0; i < max_pages; i++) {
                 pages[i] = alloc_page(GFP_NOFS);
-                if (!pages[i])
+                if (!pages[i]) {
+                        rv = ERR_PTR(-ENOMEM);
                         goto out_free;
+                }
         }
 
         memcpy(&dev->dev_id, d_id, sizeof(*d_id));
@@ -847,8 +849,10 @@ nfs4_blk_get_deviceinfo(struct nfs_server *server, const struct nfs_fh *fh,
         dprintk("%s: dev_id: %s\n", __func__, dev->dev_id.data);
         rc = nfs4_proc_getdeviceinfo(server, dev);
         dprintk("%s getdevice info returns %d\n", __func__, rc);
-        if (rc)
+        if (rc) {
+                rv = ERR_PTR(rc);
                 goto out_free;
+        }
 
         rv = nfs4_blk_decode_device(server, dev);
  out_free:
@@ -866,7 +870,7 @@ bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
         struct pnfs_devicelist *dlist = NULL;
         struct pnfs_block_dev *bdev;
         LIST_HEAD(block_disklist);
-        int status = 0, i;
+        int status, i;
 
         dprintk("%s enter\n", __func__);
 
@@ -898,8 +902,8 @@ bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
                 for (i = 0; i < dlist->num_devs; i++) {
                         bdev = nfs4_blk_get_deviceinfo(server, fh,
                                                        &dlist->dev_id[i]);
-                        if (!bdev) {
-                                status = -ENODEV;
+                        if (IS_ERR(bdev)) {
+                                status = PTR_ERR(bdev);
                                 goto out_error;
                         }
                         spin_lock(&b_mt_id->bm_lock);
diff --git a/fs/nfs/blocklayout/blocklayoutdev.c b/fs/nfs/blocklayout/blocklayoutdev.c
index a83b393fb01c..0b1fb0e25b93 100644
--- a/fs/nfs/blocklayout/blocklayoutdev.c
+++ b/fs/nfs/blocklayout/blocklayoutdev.c
@@ -131,7 +131,7 @@ struct pnfs_block_dev *
 nfs4_blk_decode_device(struct nfs_server *server,
                        struct pnfs_device *dev)
 {
-        struct pnfs_block_dev *rv = NULL;
+        struct pnfs_block_dev *rv;
         struct block_device *bd = NULL;
         struct rpc_pipe_msg msg;
         struct bl_msg_hdr bl_msg = {
@@ -141,7 +141,7 @@ nfs4_blk_decode_device(struct nfs_server *server,
         uint8_t *dataptr;
         DECLARE_WAITQUEUE(wq, current);
         struct bl_dev_msg *reply = &bl_mount_reply;
-        int offset, len, i;
+        int offset, len, i, rc;
 
         dprintk("%s CREATING PIPEFS MESSAGE\n", __func__);
         dprintk("%s: deviceid: %s, mincount: %d\n", __func__, dev->dev_id.data,
@@ -168,8 +168,10 @@ nfs4_blk_decode_device(struct nfs_server *server,
 
         dprintk("%s CALLING USERSPACE DAEMON\n", __func__);
         add_wait_queue(&bl_wq, &wq);
-        if (rpc_queue_upcall(bl_device_pipe->d_inode, &msg) < 0) {
+        rc = rpc_queue_upcall(bl_device_pipe->d_inode, &msg);
+        if (rc < 0) {
                 remove_wait_queue(&bl_wq, &wq);
+                rv = ERR_PTR(rc);
                 goto out;
         }
 
@@ -187,8 +189,9 @@ nfs4_blk_decode_device(struct nfs_server *server,
 
         bd = nfs4_blkdev_get(MKDEV(reply->major, reply->minor));
         if (IS_ERR(bd)) {
-                dprintk("%s failed to open device : %ld\n",
-                        __func__, PTR_ERR(bd));
+                rc = PTR_ERR(bd);
+                dprintk("%s failed to open device : %d\n", __func__, rc);
+                rv = ERR_PTR(rc);
                 goto out;
         }