NFS: Fix double d_drop in nfs_instantiate() error path
If the LOOKUP or GETATTR in nfs_instantiate fail, nfs_instantiate will do a
d_drop before returning. But some callers already do a d_drop in the case
of an error return. Make certain we do only one d_drop in all error paths.
This issue was introduced because over time, the symlink proc API diverged
slightly from the create/mkdir/mknod proc API. To prevent other coding
mistakes of this type, change the symlink proc API to be more like
create/mkdir/mknod and move the nfs_instantiate call into the symlink proc
routines so it is used in exactly the same way for create, mkdir, mknod,
and symlink.
Test plan:
Connectathon, all versions of NFS.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index 5a8b940..0b507bf 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -425,14 +425,15 @@
}
static int
-nfs_proc_symlink(struct inode *dir, struct qstr *name, struct qstr *path,
- struct iattr *sattr, struct nfs_fh *fhandle,
- struct nfs_fattr *fattr)
+nfs_proc_symlink(struct inode *dir, struct dentry *dentry, struct qstr *path,
+ struct iattr *sattr)
{
+ struct nfs_fh fhandle;
+ struct nfs_fattr fattr;
struct nfs_symlinkargs arg = {
.fromfh = NFS_FH(dir),
- .fromname = name->name,
- .fromlen = name->len,
+ .fromname = dentry->d_name.name,
+ .fromlen = dentry->d_name.len,
.topath = path->name,
.tolen = path->len,
.sattr = sattr
@@ -445,11 +446,23 @@
if (path->len > NFS2_MAXPATHLEN)
return -ENAMETOOLONG;
- dprintk("NFS call symlink %s -> %s\n", name->name, path->name);
- nfs_fattr_init(fattr);
- fhandle->size = 0;
+
+ dprintk("NFS call symlink %s -> %s\n", dentry->d_name.name,
+ path->name);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
+
+ /*
+ * V2 SYMLINK requests don't return any attributes. Setting the
+ * filehandle size to zero indicates to nfs_instantiate that it
+ * should fill in the data with a LOOKUP call on the wire.
+ */
+ if (status == 0) {
+ nfs_fattr_init(&fattr);
+ fhandle.size = 0;
+ status = nfs_instantiate(dentry, &fhandle, &fattr);
+ }
+
dprintk("NFS reply symlink: %d\n", status);
return status;
}