[086/264] pnfsblock: fix return code confusion

From: Greg KH
Date: Wed Nov 09 2011 - 22:39:21 EST


3.1-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jim Rees <rees@xxxxxxxxx>

commit 516f2e24faa7548a61d9ba790958528469c2e284 upstream.

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@xxxxxxxxx>
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
fs/nfs/blocklayout/blocklayout.c | 20 ++++++++++++--------
fs/nfs/blocklayout/blocklayoutdev.c | 13 ++++++++-----
2 files changed, 20 insertions(+), 13 deletions(-)

--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -805,7 +805,7 @@ nfs4_blk_get_deviceinfo(struct nfs_serve
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_serve
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_serve
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 *s
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 *s
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);
--- 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
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

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

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;
}



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