From acfa4380efe77e290d3a96b11cd4c9f24f4fbb18 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 4 Dec 2008 10:06:33 -0500
Subject: [PATCH] inode->i_op is never NULL

We used to have rather schizophrenic set of checks for NULL ->i_op even
though it had been eliminated years ago.  You'd need to go out of your
way to set it to NULL explicitly _and_ a bunch of code would die on
such inodes anyway.  After killing two remaining places that still
did that bogosity, all that crap can go away.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/cifs/inode.c      |  2 +-
 fs/ecryptfs/inode.c  |  3 +--
 fs/namei.c           | 32 +++++++++++++-------------------
 fs/nfsd/vfs.c        |  8 ++++----
 fs/open.c            |  2 +-
 fs/stat.c            |  2 +-
 fs/xattr.c           |  2 +-
 mm/memory.c          |  4 ++--
 mm/nommu.c           |  2 +-
 security/commoncap.c |  6 +++---
 10 files changed, 28 insertions(+), 35 deletions(-)

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index f247da9f4ed..5ab9896fdcb 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1641,7 +1641,7 @@ do_expand:
 	i_size_write(inode, offset);
 	spin_unlock(&inode->i_lock);
 out_truncate:
-	if (inode->i_op && inode->i_op->truncate)
+	if (inode->i_op->truncate)
 		inode->i_op->truncate(inode);
 	return 0;
 out_sig:
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 5e78fc17988..0111906a887 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -612,8 +612,7 @@ ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz)
 	struct ecryptfs_crypt_stat *crypt_stat;
 
 	lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	if (!lower_dentry->d_inode->i_op ||
-	    !lower_dentry->d_inode->i_op->readlink) {
+	if (!lower_dentry->d_inode->i_op->readlink) {
 		rc = -EINVAL;
 		goto out;
 	}
diff --git a/fs/namei.c b/fs/namei.c
index dd5c9f0bf82..1f6656c3d1b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -257,7 +257,7 @@ int inode_permission(struct inode *inode, int mask)
 			return -EACCES;
 	}
 
-	if (inode->i_op && inode->i_op->permission)
+	if (inode->i_op->permission)
 		retval = inode->i_op->permission(inode, mask);
 	else
 		retval = generic_permission(inode, mask, NULL);
@@ -432,7 +432,7 @@ static int exec_permission_lite(struct inode *inode)
 {
 	umode_t	mode = inode->i_mode;
 
-	if (inode->i_op && inode->i_op->permission)
+	if (inode->i_op->permission)
 		return -EAGAIN;
 
 	if (current_fsuid() == inode->i_uid)
@@ -908,9 +908,6 @@ static int __link_path_walk(const char *name, struct nameidata *nd)
 		inode = next.dentry->d_inode;
 		if (!inode)
 			goto out_dput;
-		err = -ENOTDIR; 
-		if (!inode->i_op)
-			goto out_dput;
 
 		if (inode->i_op->follow_link) {
 			err = do_follow_link(&next, nd);
@@ -920,9 +917,6 @@ static int __link_path_walk(const char *name, struct nameidata *nd)
 			inode = nd->path.dentry->d_inode;
 			if (!inode)
 				break;
-			err = -ENOTDIR; 
-			if (!inode->i_op)
-				break;
 		} else
 			path_to_nameidata(&next, nd);
 		err = -ENOTDIR; 
@@ -961,7 +955,7 @@ last_component:
 			break;
 		inode = next.dentry->d_inode;
 		if ((lookup_flags & LOOKUP_FOLLOW)
-		    && inode && inode->i_op && inode->i_op->follow_link) {
+		    && inode && inode->i_op->follow_link) {
 			err = do_follow_link(&next, nd);
 			if (err)
 				goto return_err;
@@ -973,7 +967,7 @@ last_component:
 			break;
 		if (lookup_flags & LOOKUP_DIRECTORY) {
 			err = -ENOTDIR; 
-			if (!inode->i_op || !inode->i_op->lookup)
+			if (!inode->i_op->lookup)
 				break;
 		}
 		goto return_base;
@@ -1469,7 +1463,7 @@ int vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 	if (error)
 		return error;
 
-	if (!dir->i_op || !dir->i_op->create)
+	if (!dir->i_op->create)
 		return -EACCES;	/* shouldn't it be ENOSYS? */
 	mode &= S_IALLUGO;
 	mode |= S_IFREG;
@@ -1752,7 +1746,7 @@ do_last:
 	error = -ENOENT;
 	if (!path.dentry->d_inode)
 		goto exit_dput;
-	if (path.dentry->d_inode->i_op && path.dentry->d_inode->i_op->follow_link)
+	if (path.dentry->d_inode->i_op->follow_link)
 		goto do_link;
 
 	path_to_nameidata(&path, &nd);
@@ -1933,7 +1927,7 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
 	if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD))
 		return -EPERM;
 
-	if (!dir->i_op || !dir->i_op->mknod)
+	if (!dir->i_op->mknod)
 		return -EPERM;
 
 	error = devcgroup_inode_mknod(mode, dev);
@@ -2035,7 +2029,7 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 	if (error)
 		return error;
 
-	if (!dir->i_op || !dir->i_op->mkdir)
+	if (!dir->i_op->mkdir)
 		return -EPERM;
 
 	mode &= (S_IRWXUGO|S_ISVTX);
@@ -2126,7 +2120,7 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry)
 	if (error)
 		return error;
 
-	if (!dir->i_op || !dir->i_op->rmdir)
+	if (!dir->i_op->rmdir)
 		return -EPERM;
 
 	DQUOT_INIT(dir);
@@ -2213,7 +2207,7 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry)
 	if (error)
 		return error;
 
-	if (!dir->i_op || !dir->i_op->unlink)
+	if (!dir->i_op->unlink)
 		return -EPERM;
 
 	DQUOT_INIT(dir);
@@ -2320,7 +2314,7 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname)
 	if (error)
 		return error;
 
-	if (!dir->i_op || !dir->i_op->symlink)
+	if (!dir->i_op->symlink)
 		return -EPERM;
 
 	error = security_inode_symlink(dir, dentry, oldname);
@@ -2401,7 +2395,7 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de
 	 */
 	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 		return -EPERM;
-	if (!dir->i_op || !dir->i_op->link)
+	if (!dir->i_op->link)
 		return -EPERM;
 	if (S_ISDIR(inode->i_mode))
 		return -EPERM;
@@ -2608,7 +2602,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	if (error)
 		return error;
 
-	if (!old_dir->i_op || !old_dir->i_op->rename)
+	if (!old_dir->i_op->rename)
 		return -EPERM;
 
 	DQUOT_INIT(old_dir);
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index d1c5f787b36..5245a396500 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1211,7 +1211,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	dirp = dentry->d_inode;
 
 	err = nfserr_notdir;
-	if(!dirp->i_op || !dirp->i_op->lookup)
+	if (!dirp->i_op->lookup)
 		goto out;
 	/*
 	 * Check whether the response file handle has been verified yet.
@@ -1347,7 +1347,7 @@ nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	/* Get all the sanity checks out of the way before
 	 * we lock the parent. */
 	err = nfserr_notdir;
-	if(!dirp->i_op || !dirp->i_op->lookup)
+	if (!dirp->i_op->lookup)
 		goto out;
 	fh_lock_nested(fhp, I_MUTEX_PARENT);
 
@@ -1482,7 +1482,7 @@ nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
 	inode = dentry->d_inode;
 
 	err = nfserr_inval;
-	if (!inode->i_op || !inode->i_op->readlink)
+	if (!inode->i_op->readlink)
 		goto out;
 
 	touch_atime(fhp->fh_export->ex_path.mnt, dentry);
@@ -2162,7 +2162,7 @@ nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
 	size_t size;
 	int error;
 
-	if (!IS_POSIXACL(inode) || !inode->i_op ||
+	if (!IS_POSIXACL(inode) ||
 	    !inode->i_op->setxattr || !inode->i_op->removexattr)
 		return -EOPNOTSUPP;
 	switch(type) {
diff --git a/fs/open.c b/fs/open.c
index 1cd7d40e999..d882fd2351d 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -412,7 +412,7 @@ asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len)
 	if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
 		goto out_fput;
 
-	if (inode->i_op && inode->i_op->fallocate)
+	if (inode->i_op->fallocate)
 		ret = inode->i_op->fallocate(inode, mode, offset, len);
 	else
 		ret = -EOPNOTSUPP;
diff --git a/fs/stat.c b/fs/stat.c
index 7c46fbeb8b7..7e12a6f8279 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -305,7 +305,7 @@ asmlinkage long sys_readlinkat(int dfd, const char __user *pathname,
 		struct inode *inode = path.dentry->d_inode;
 
 		error = -EINVAL;
-		if (inode->i_op && inode->i_op->readlink) {
+		if (inode->i_op->readlink) {
 			error = security_inode_readlink(path.dentry);
 			if (!error) {
 				touch_atime(path.mnt, path.dentry);
diff --git a/fs/xattr.c b/fs/xattr.c
index 468377e6653..237804cd6b5 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -175,7 +175,7 @@ vfs_listxattr(struct dentry *d, char *list, size_t size)
 	if (error)
 		return error;
 	error = -EOPNOTSUPP;
-	if (d->d_inode->i_op && d->d_inode->i_op->listxattr) {
+	if (d->d_inode->i_op->listxattr) {
 		error = d->d_inode->i_op->listxattr(d, list, size);
 	} else {
 		error = security_inode_listsecurity(d->d_inode, list, size);
diff --git a/mm/memory.c b/mm/memory.c
index 0a2010a9518..7b9db658aca 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2266,7 +2266,7 @@ int vmtruncate(struct inode * inode, loff_t offset)
 		unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
 	}
 
-	if (inode->i_op && inode->i_op->truncate)
+	if (inode->i_op->truncate)
 		inode->i_op->truncate(inode);
 	return 0;
 
@@ -2286,7 +2286,7 @@ int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
 	 * a way to truncate a range of blocks (punch a hole) -
 	 * we should return failure right now.
 	 */
-	if (!inode->i_op || !inode->i_op->truncate_range)
+	if (!inode->i_op->truncate_range)
 		return -ENOSYS;
 
 	mutex_lock(&inode->i_mutex);
diff --git a/mm/nommu.c b/mm/nommu.c
index 7695dc85078..1c28ea3a4e9 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -86,7 +86,7 @@ do_expand:
 	i_size_write(inode, offset);
 
 out_truncate:
-	if (inode->i_op && inode->i_op->truncate)
+	if (inode->i_op->truncate)
 		inode->i_op->truncate(inode);
 	return 0;
 out_sig:
diff --git a/security/commoncap.c b/security/commoncap.c
index 79713545cd6..69fc9952650 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -238,7 +238,7 @@ int cap_inode_need_killpriv(struct dentry *dentry)
 	struct inode *inode = dentry->d_inode;
 	int error;
 
-	if (!inode->i_op || !inode->i_op->getxattr)
+	if (!inode->i_op->getxattr)
 	       return 0;
 
 	error = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0);
@@ -259,7 +259,7 @@ int cap_inode_killpriv(struct dentry *dentry)
 {
 	struct inode *inode = dentry->d_inode;
 
-	if (!inode->i_op || !inode->i_op->removexattr)
+	if (!inode->i_op->removexattr)
 	       return 0;
 
 	return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS);
@@ -317,7 +317,7 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data
 
 	memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data));
 
-	if (!inode || !inode->i_op || !inode->i_op->getxattr)
+	if (!inode || !inode->i_op->getxattr)
 		return -ENODATA;
 
 	size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps,
-- 
2.41.1