From 7e34bc524ecae3a04d8cc427ee76ddad826a937b Mon Sep 17 00:00:00 2001
From: Julia Lawall <julia@diku.dk>
Date: Sat, 22 May 2010 12:01:14 +0200
Subject: [PATCH] fs/ceph: Use ERR_CAST

Use ERR_CAST(x) rather than ERR_PTR(PTR_ERR(x)).  The former makes more
clear what is the purpose of the operation, which otherwise looks like a
no-op.

In the case of fs/ceph/inode.c, ERR_CAST is not needed, because the type of
the returned value is the same as the type of the enclosing function.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
type T;
T x;
identifier f;
@@

T f (...) { <+...
- ERR_PTR(PTR_ERR(x))
+ x
 ...+> }

@@
expression x;
@@

- ERR_PTR(PTR_ERR(x))
+ ERR_CAST(x)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Sage Weil <sage@newdream.net>
---
 fs/ceph/dir.c    | 2 +-
 fs/ceph/export.c | 2 +-
 fs/ceph/file.c   | 2 +-
 fs/ceph/inode.c  | 2 +-
 fs/ceph/osdmap.c | 2 +-
 fs/ceph/super.c  | 2 +-
 6 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 4fd3090..a86c1d5 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -587,7 +587,7 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 		CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
 	req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
 	if (IS_ERR(req))
-		return ERR_PTR(PTR_ERR(req));
+		return ERR_CAST(req);
 	req->r_dentry = dget(dentry);
 	req->r_num_caps = 2;
 	/* we only need inode linkage */
diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index 1744764..4480cb1 100644
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -133,7 +133,7 @@ static struct dentry *__cfh_to_dentry(struct super_block *sb,
 		req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPHASH,
 					       USE_ANY_MDS);
 		if (IS_ERR(req))
-			return ERR_PTR(PTR_ERR(req));
+			return ERR_CAST(req);
 
 		req->r_ino1 = vino;
 		req->r_ino2.ino = cfh->parent_ino;
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 0611ec3..f06f902 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -230,7 +230,7 @@ struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
 	/* do the open */
 	req = prepare_open_request(dir->i_sb, flags, mode);
 	if (IS_ERR(req))
-		return ERR_PTR(PTR_ERR(req));
+		return ERR_CAST(req);
 	req->r_dentry = dget(dentry);
 	req->r_num_caps = 2;
 	if (flags & O_CREAT) {
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index a81b8b6..226f5a5 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -69,7 +69,7 @@ struct inode *ceph_get_snapdir(struct inode *parent)
 
 	BUG_ON(!S_ISDIR(parent->i_mode));
 	if (IS_ERR(inode))
-		return ERR_PTR(PTR_ERR(inode));
+		return inode;
 	inode->i_mode = parent->i_mode;
 	inode->i_uid = parent->i_uid;
 	inode->i_gid = parent->i_gid;
diff --git a/fs/ceph/osdmap.c b/fs/ceph/osdmap.c
index cfdd8f4..ddc656f 100644
--- a/fs/ceph/osdmap.c
+++ b/fs/ceph/osdmap.c
@@ -706,7 +706,7 @@ struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end,
 		     len, *p, end);
 		newcrush = crush_decode(*p, min(*p+len, end));
 		if (IS_ERR(newcrush))
-			return ERR_PTR(PTR_ERR(newcrush));
+			return ERR_CAST(newcrush);
 	}
 
 	/* new flags? */
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index bac1389..9b46bb9 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -738,7 +738,7 @@ static struct dentry *open_root_dentry(struct ceph_client *client,
 	dout("open_root_inode opening '%s'\n", path);
 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);
 	if (IS_ERR(req))
-		return ERR_PTR(PTR_ERR(req));
+		return ERR_CAST(req);
 	req->r_path1 = kstrdup(path, GFP_NOFS);
 	req->r_ino1.ino = CEPH_INO_ROOT;
 	req->r_ino1.snap = CEPH_NOSNAP;
-- 
1.8.2.3