Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull more VFS bits from Al Viro:
"Unfortunately, it looks like xattr series will have to wait until the
next cycle ;-/

This pile contains 9p cleanups and fixes (races in v9fs_fid_add()
etc), fixup for nommu breakage in shmem.c, several cleanups and a bit
more file_inode() work"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
constify path_get/path_put and fs_struct.c stuff
fix nommu breakage in shmem.c
cache the value of file_inode() in struct file
9p: if v9fs_fid_lookup() gets to asking server, it'd better have hashed dentry
9p: make sure ->lookup() adds fid to the right dentry
9p: untangle ->lookup() a bit
9p: double iput() in ->lookup() if d_materialise_unique() fails
9p: v9fs_fid_add() can't fail now
v9fs: get rid of v9fs_dentry
9p: turn fid->dlist into hlist
9p: don't bother with private lock in ->d_fsdata; dentry->d_lock will do just fine
more file_inode() open-coded instances
selinux: opened file can't have NULL or negative ->f_path.dentry

(In the meantime, the hlist traversal macros have changed, so this
required a semantic conflict fixup for the newly hlistified fid->dlist)

arch/s390/hypfs/inode.c

···
 			      unsigned long nr_segs, loff_t offset)
 {
 	int rc;
-	struct super_block *sb;
-	struct hypfs_sb_info *fs_info;
+	struct super_block *sb = file_inode(iocb->ki_filp)->i_sb;
+	struct hypfs_sb_info *fs_info = sb->s_fs_info;
 	size_t count = iov_length(iov, nr_segs);
 
-	sb = iocb->ki_filp->f_path.dentry->d_inode->i_sb;
-	fs_info = sb->s_fs_info;
 	/*
 	 * Currently we only allow one update per second for two reasons:
 	 * 1. diag 204 is VERY expensive

arch/x86/kernel/msr.c

···
 	u32 __user *tmp = (u32 __user *) buf;
 	u32 data[2];
 	u32 reg = *ppos;
-	int cpu = iminor(file->f_path.dentry->d_inode);
+	int cpu = iminor(file_inode(file));
 	int err = 0;
 	ssize_t bytes = 0;
 
···
 	const u32 __user *tmp = (const u32 __user *)buf;
 	u32 data[2];
 	u32 reg = *ppos;
-	int cpu = iminor(file->f_path.dentry->d_inode);
+	int cpu = iminor(file_inode(file));
 	int err = 0;
 	ssize_t bytes = 0;
 
···
 {
 	u32 __user *uregs = (u32 __user *)arg;
 	u32 regs[8];
-	int cpu = iminor(file->f_path.dentry->d_inode);
+	int cpu = iminor(file_inode(file));
 	int err;
 
 	switch (ioc) {
···
 
 static int msr_open(struct inode *inode, struct file *file)
 {
-	unsigned int cpu;
+	unsigned int cpu = iminor(file_inode(file));
 	struct cpuinfo_x86 *c;
 
 	if (!capable(CAP_SYS_RAWIO))
 		return -EPERM;
 
-	cpu = iminor(file->f_path.dentry->d_inode);
 	if (cpu >= nr_cpu_ids || !cpu_online(cpu))
 		return -ENXIO;	/* No such CPU */
 

drivers/staging/comedi/comedi_fops.c

···
 			    struct comedi_devinfo __user *arg,
 			    struct file *file)
 {
-	const unsigned minor = iminor(file->f_dentry->d_inode);
+	const unsigned minor = iminor(file_inode(file));
 	struct comedi_file_info *info = comedi_file_info_from_minor(minor);
 	struct comedi_subdevice *s;
 	struct comedi_devinfo devinfo;
···
 static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
 				  unsigned long arg)
 {
-	const unsigned minor = iminor(file->f_dentry->d_inode);
+	const unsigned minor = iminor(file_inode(file));
 	struct comedi_file_info *info = comedi_file_info_from_minor(minor);
 	struct comedi_device *dev = comedi_dev_from_file_info(info);
 	int rc;
···
 
 static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
 {
-	const unsigned minor = iminor(file->f_dentry->d_inode);
+	const unsigned minor = iminor(file_inode(file));
 	struct comedi_file_info *info = comedi_file_info_from_minor(minor);
 	struct comedi_device *dev = comedi_dev_from_file_info(info);
 	struct comedi_subdevice *s;
···
 static unsigned int comedi_poll(struct file *file, poll_table *wait)
 {
 	unsigned int mask = 0;
-	const unsigned minor = iminor(file->f_dentry->d_inode);
+	const unsigned minor = iminor(file_inode(file));
 	struct comedi_file_info *info = comedi_file_info_from_minor(minor);
 	struct comedi_device *dev = comedi_dev_from_file_info(info);
 	struct comedi_subdevice *s;
···
 	struct comedi_async *async;
 	int n, m, count = 0, retval = 0;
 	DECLARE_WAITQUEUE(wait, current);
-	const unsigned minor = iminor(file->f_dentry->d_inode);
+	const unsigned minor = iminor(file_inode(file));
 	struct comedi_file_info *info = comedi_file_info_from_minor(minor);
 	struct comedi_device *dev = comedi_dev_from_file_info(info);
 
···
 	struct comedi_async *async;
 	int n, m, count = 0, retval = 0;
 	DECLARE_WAITQUEUE(wait, current);
-	const unsigned minor = iminor(file->f_dentry->d_inode);
+	const unsigned minor = iminor(file_inode(file));
 	struct comedi_file_info *info = comedi_file_info_from_minor(minor);
 	struct comedi_device *dev = comedi_dev_from_file_info(info);
 
···
 
 static int comedi_fasync(int fd, struct file *file, int on)
 {
-	const unsigned minor = iminor(file->f_dentry->d_inode);
+	const unsigned minor = iminor(file_inode(file));
 	struct comedi_device *dev = comedi_dev_from_minor(minor);
 
 	if (!dev)

drivers/tty/tty_io.c

···
 			loff_t *ppos)
 {
 	int i;
-	struct inode *inode = file->f_path.dentry->d_inode;
 	struct tty_struct *tty = file_tty(file);
 	struct tty_ldisc *ld;
 
-	if (tty_paranoia_check(tty, inode, "tty_read"))
+	if (tty_paranoia_check(tty, file_inode(file), "tty_read"))
 		return -EIO;
 	if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
 		return -EIO;
···
 static ssize_t tty_write(struct file *file, const char __user *buf,
 						size_t count, loff_t *ppos)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
 	struct tty_struct *tty = file_tty(file);
  	struct tty_ldisc *ld;
 	ssize_t ret;
 
-	if (tty_paranoia_check(tty, inode, "tty_write"))
+	if (tty_paranoia_check(tty, file_inode(file), "tty_write"))
 		return -EIO;
 	if (!tty || !tty->ops->write ||
 		(test_bit(TTY_IO_ERROR, &tty->flags)))
···
 	struct tty_ldisc *ld;
 	int ret = 0;
 
-	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll"))
+	if (tty_paranoia_check(tty, file_inode(filp), "tty_poll"))
 		return 0;
 
 	ld = tty_ldisc_ref_wait(tty);
···
 	unsigned long flags;
 	int retval = 0;
 
-	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync"))
+	if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync"))
 		goto out;
 
 	retval = fasync_helper(fd, filp, on, &tty->fasync);
···
 	void __user *p = (void __user *)arg;
 	int retval;
 	struct tty_ldisc *ld;
-	struct inode *inode = file->f_dentry->d_inode;
 
-	if (tty_paranoia_check(tty, inode, "tty_ioctl"))
+	if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl"))
 		return -EINVAL;
 
 	real_tty = tty_pair_get_tty(tty);
···
 static long tty_compat_ioctl(struct file *file, unsigned int cmd,
 				unsigned long arg)
 {
-	struct inode *inode = file->f_dentry->d_inode;
 	struct tty_struct *tty = file_tty(file);
 	struct tty_ldisc *ld;
 	int retval = -ENOIOCTLCMD;
 
-	if (tty_paranoia_check(tty, inode, "tty_ioctl"))
+	if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl"))
 		return -EINVAL;
 
 	if (tty->ops->compat_ioctl) {

fs/9p/fid.c

···
  *
  */
 
-int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
+static inline void __add_fid(struct dentry *dentry, struct p9_fid *fid)
 {
-	struct v9fs_dentry *dent;
+	hlist_add_head(&fid->dlist, (struct hlist_head *)&dentry->d_fsdata);
+}
 
-	p9_debug(P9_DEBUG_VFS, "fid %d dentry %s\n",
-		 fid->fid, dentry->d_name.name);
-
-	dent = dentry->d_fsdata;
-	if (!dent) {
-		dent = kmalloc(sizeof(struct v9fs_dentry), GFP_KERNEL);
-		if (!dent)
-			return -ENOMEM;
-
-		spin_lock_init(&dent->lock);
-		INIT_LIST_HEAD(&dent->fidlist);
-		dentry->d_fsdata = dent;
-	}
-
-	spin_lock(&dent->lock);
-	list_add(&fid->dlist, &dent->fidlist);
-	spin_unlock(&dent->lock);
-
-	return 0;
+void v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
+{
+	spin_lock(&dentry->d_lock);
+	__add_fid(dentry, fid);
+	spin_unlock(&dentry->d_lock);
 }
 
 /**
···
 
 static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any)
 {
-	struct v9fs_dentry *dent;
 	struct p9_fid *fid, *ret;
 
 	p9_debug(P9_DEBUG_VFS, " dentry: %s (%p) uid %d any %d\n",
 		 dentry->d_name.name, dentry, from_kuid(&init_user_ns, uid),
 		 any);
-	dent = (struct v9fs_dentry *) dentry->d_fsdata;
 	ret = NULL;
-	if (dent) {
-		spin_lock(&dent->lock);
-		list_for_each_entry(fid, &dent->fidlist, dlist) {
+	/* we'll recheck under lock if there's anything to look in */
+	if (dentry->d_fsdata) {
+		struct hlist_head *h = (struct hlist_head *)&dentry->d_fsdata;
+		spin_lock(&dentry->d_lock);
+		hlist_for_each_entry(fid, h, dlist) {
 			if (any || uid_eq(fid->uid, uid)) {
 				ret = fid;
 				break;
 			}
 		}
-		spin_unlock(&dent->lock);
+		spin_unlock(&dentry->d_lock);
 	}
 
 	return ret;
···
 	}
 	kfree(wnames);
 fid_out:
-	if (!IS_ERR(fid))
-		v9fs_fid_add(dentry, fid);
+	if (!IS_ERR(fid)) {
+		spin_lock(&dentry->d_lock);
+		if (d_unhashed(dentry)) {
+			spin_unlock(&dentry->d_lock);
+			p9_client_clunk(fid);
+			fid = ERR_PTR(-ENOENT);
+		} else {
+			__add_fid(dentry, fid);
+			spin_unlock(&dentry->d_lock);
+		}
+	}
 err_out:
 	up_read(&v9ses->rename_sem);
 	return fid;

fs/9p/fid.h

···
 #define FS_9P_FID_H
 #include <linux/list.h>
 
-/**
- * struct v9fs_dentry - 9p private data stored in dentry d_fsdata
- * @lock: protects the fidlist
- * @fidlist: list of FIDs currently associated with this dentry
- *
- * This structure defines the 9p private data associated with
- * a particular dentry.  In particular, this private data is used
- * to lookup which 9P FID handle should be used for a particular VFS
- * operation.  FID handles are associated with dentries instead of
- * inodes in order to more closely map functionality to the Plan 9
- * expected behavior for FID reclaimation and tracking.
- *
- * See Also: Mapping FIDs to Linux VFS model in
- * Design and Implementation of the Linux 9P File System documentation
- */
-struct v9fs_dentry {
-	spinlock_t lock; /* protect fidlist */
-	struct list_head fidlist;
-};
-
 struct p9_fid *v9fs_fid_lookup(struct dentry *dentry);
 struct p9_fid *v9fs_fid_clone(struct dentry *dentry);
-int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid);
+void v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid);
 struct p9_fid *v9fs_writeback_fid(struct dentry *dentry);
 #endif

fs/9p/vfs_dentry.c

···
 
 static void v9fs_dentry_release(struct dentry *dentry)
 {
-	struct v9fs_dentry *dent;
-	struct p9_fid *temp, *current_fid;
-
+	struct hlist_node *p, *n;
 	p9_debug(P9_DEBUG_VFS, " dentry: %s (%p)\n",
 		 dentry->d_name.name, dentry);
-	dent = dentry->d_fsdata;
-	if (dent) {
-		list_for_each_entry_safe(current_fid, temp, &dent->fidlist,
-									dlist) {
-			p9_client_clunk(current_fid);
-		}
-
-		kfree(dent);
-		dentry->d_fsdata = NULL;
-	}
+	hlist_for_each_safe(p, n, (struct hlist_head *)&dentry->d_fsdata)
+		p9_client_clunk(hlist_entry(p, struct p9_fid, dlist));
+	dentry->d_fsdata = NULL;
 }
 
 static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)

fs/9p/vfs_inode.c

···
 				   "inode creation failed %d\n", err);
 			goto error;
 		}
-		err = v9fs_fid_add(dentry, fid);
-		if (err < 0)
-			goto error;
+		v9fs_fid_add(dentry, fid);
 		d_instantiate(dentry, inode);
 	}
 	return ofid;
···
 	struct p9_fid *dfid, *fid;
 	struct inode *inode;
 	char *name;
-	int result = 0;
 
 	p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p flags: %x\n",
 		 dir, dentry->d_name.name, dentry, flags);
···
 	name = (char *) dentry->d_name.name;
 	fid = p9_client_walk(dfid, 1, &name, 1);
 	if (IS_ERR(fid)) {
-		result = PTR_ERR(fid);
-		if (result == -ENOENT) {
-			inode = NULL;
-			goto inst_out;
+		if (fid == ERR_PTR(-ENOENT)) {
+			d_add(dentry, NULL);
+			return NULL;
 		}
-
-		return ERR_PTR(result);
+		return ERR_CAST(fid);
 	}
 	/*
 	 * Make sure we don't use a wrong inode due to parallel
···
 	else
 		inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 	if (IS_ERR(inode)) {
-		result = PTR_ERR(inode);
-		inode = NULL;
-		goto error;
+		p9_client_clunk(fid);
+		return ERR_CAST(inode);
 	}
-	result = v9fs_fid_add(dentry, fid);
-	if (result < 0)
-		goto error_iput;
-inst_out:
 	/*
 	 * If we had a rename on the server and a parallel lookup
 	 * for the new name, then make sure we instantiate with
···
 	 * k/b.
 	 */
 	res = d_materialise_unique(dentry, inode);
-	if (!IS_ERR(res))
-		return res;
-	result = PTR_ERR(res);
-error_iput:
-	iput(inode);
-error:
-	p9_client_clunk(fid);
-
-	return ERR_PTR(result);
+	if (!res)
+		v9fs_fid_add(dentry, fid);
+	else if (!IS_ERR(res))
+		v9fs_fid_add(res, fid);
+	else
+		p9_client_clunk(fid);
+	return res;
 }
 
 static int

fs/9p/vfs_inode_dotl.c

···
 	/* Now set the ACL based on the default value */
 	v9fs_set_create_acl(inode, fid, dacl, pacl);
 
-	err = v9fs_fid_add(dentry, fid);
-	if (err < 0)
-		goto error;
+	v9fs_fid_add(dentry, fid);
 	d_instantiate(dentry, inode);
 
 	v9inode = V9FS_I(inode);
···
 				 err);
 			goto error;
 		}
-		err = v9fs_fid_add(dentry, fid);
-		if (err < 0)
-			goto error;
+		v9fs_fid_add(dentry, fid);
 		v9fs_set_create_acl(inode, fid, dacl, pacl);
 		d_instantiate(dentry, inode);
 		fid = NULL;
+		err = 0;
 	} else {
 		/*
 		 * Not in cached mode. No need to populate
···
 				 err);
 			goto error;
 		}
-		err = v9fs_fid_add(dentry, fid);
-		if (err < 0)
-			goto error;
+		v9fs_fid_add(dentry, fid);
 		d_instantiate(dentry, inode);
 		fid = NULL;
+		err = 0;
 	} else {
 		/* Not in cached mode. No need to populate inode with stat */
 		inode = v9fs_get_inode(dir->i_sb, S_IFLNK, 0);
···
 			goto error;
 		}
 		v9fs_set_create_acl(inode, fid, dacl, pacl);
-		err = v9fs_fid_add(dentry, fid);
-		if (err < 0)
-			goto error;
+		v9fs_fid_add(dentry, fid);
 		d_instantiate(dentry, inode);
 		fid = NULL;
+		err = 0;
 	} else {
 		/*
 		 * Not in cached mode. No need to populate inode with stat.

fs/ext4/indirect.c

···
 
 int ext4_ind_punch_hole(struct file *file, loff_t offset, loff_t length)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	struct super_block *sb = inode->i_sb;
 	ext4_lblk_t first_block, stop_block;
 	struct address_space *mapping = inode->i_mapping;

fs/f2fs/file.c

···
 						struct vm_fault *vmf)
 {
 	struct page *page = vmf->page;
-	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(vma->vm_file);
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	block_t old_blk_addr;
 	struct dnode_of_data dn;
···
 static long f2fs_fallocate(struct file *file, int mode,
 				loff_t offset, loff_t len)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	long ret;
 
 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
···
 
 long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
-	struct inode *inode = filp->f_dentry->d_inode;
+	struct inode *inode = file_inode(filp);
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 	unsigned int flags;
 	int ret;

fs/file_table.c

···
 		return file;
 
 	file->f_path = *path;
+	file->f_inode = path->dentry->d_inode;
 	file->f_mapping = path->dentry->d_inode->i_mapping;
 	file->f_mode = mode;
 	file->f_op = fop;
···
 		drop_file_write_access(file);
 	file->f_path.dentry = NULL;
 	file->f_path.mnt = NULL;
+	file->f_inode = NULL;
 	file_free(file);
 	dput(dentry);
 	mntput(mnt);

fs/fs_struct.c

···
  * Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values.
  * It can block.
  */
-void set_fs_root(struct fs_struct *fs, struct path *path)
+void set_fs_root(struct fs_struct *fs, const struct path *path)
 {
 	struct path old_root;
 
···
  * Replace the fs->{pwdmnt,pwd} with {mnt,dentry}. Put the old values.
  * It can block.
  */
-void set_fs_pwd(struct fs_struct *fs, struct path *path)
+void set_fs_pwd(struct fs_struct *fs, const struct path *path)
 {
 	struct path old_pwd;
 
···
 	return 1;
 }
 
-void chroot_fs_refs(struct path *old_root, struct path *new_root)
+void chroot_fs_refs(const struct path *old_root, const struct path *new_root)
 {
 	struct task_struct *g, *p;
 	struct fs_struct *fs;

fs/fuse/dev.c

···
 
 void fuse_force_forget(struct file *file, u64 nodeid)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_req *req;
 	struct fuse_forget_in inarg;

fs/fuse/file.c

···
 
 static int fuse_flush(struct file *file, fl_owner_t id)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_file *ff = file->private_data;
 	struct fuse_req *req;
···
 				  unsigned long nr_segs, loff_t *ppos)
 {
 	ssize_t res;
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 
 	if (is_bad_inode(inode))
 		return -EIO;
···
 static ssize_t __fuse_direct_write(struct file *file, const struct iovec *iov,
 				   unsigned long nr_segs, loff_t *ppos)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	size_t count = iov_length(iov, nr_segs);
 	ssize_t res;
 
···
 				 size_t count, loff_t *ppos)
 {
 	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	ssize_t res;
 
 	if (is_bad_inode(inode))
···
 static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) {
-		struct inode *inode = file->f_dentry->d_inode;
+		struct inode *inode = file_inode(file);
 		struct fuse_conn *fc = get_fuse_conn(inode);
 		struct fuse_inode *fi = get_fuse_inode(inode);
 		struct fuse_file *ff = file->private_data;
···
 			 const struct file_lock *fl, int opcode, pid_t pid,
 			 int flock)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_file *ff = file->private_data;
 	struct fuse_lk_in *arg = &req->misc.lk_in;
···
 
 static int fuse_getlk(struct file *file, struct file_lock *fl)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_req *req;
 	struct fuse_lk_out outarg;
···
 
 static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_req *req;
 	int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
···
 
 static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	int err;
 
···
 
 static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	int err;
 
···
 static loff_t fuse_file_llseek(struct file *file, loff_t offset, int whence)
 {
 	loff_t retval;
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 
 	/* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */
 	if (whence == SEEK_CUR || whence == SEEK_SET)
···
 long fuse_ioctl_common(struct file *file, unsigned int cmd,
 		       unsigned long arg, unsigned int flags)
 {
-	struct inode *inode = file->f_dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	struct fuse_conn *fc = get_fuse_conn(inode);
 
 	if (!fuse_allow_current_process(fc))

fs/internal.h

···
 /*
  * fs_struct.c
  */
-extern void chroot_fs_refs(struct path *, struct path *);
+extern void chroot_fs_refs(const struct path *, const struct path *);
 
 /*
  * file_table.c

fs/namei.c

···
  *
  * Given a path increment the reference count to the dentry and the vfsmount.
  */
-void path_get(struct path *path)
+void path_get(const struct path *path)
 {
 	mntget(path->mnt);
 	dget(path->dentry);
···
  *
  * Given a path decrement the reference count to the dentry and the vfsmount.
  */
-void path_put(struct path *path)
+void path_put(const struct path *path)
 {
 	dput(path->dentry);
 	mntput(path->mnt);

fs/open.c

···
 		f->f_mode = FMODE_PATH;
 
 	path_get(&f->f_path);
-	inode = file_inode(f);
+	inode = f->f_inode = f->f_path.dentry->d_inode;
 	if (f->f_mode & FMODE_WRITE) {
 		error = __get_file_write_access(inode, f->f_path.mnt);
 		if (error)
···
 	path_put(&f->f_path);
 	f->f_path.mnt = NULL;
 	f->f_path.dentry = NULL;
+	f->f_inode = NULL;
 	return error;
 }
 

fs/seq_file.c

···
 /**
  *	seq_release -	free the structures associated with sequential file.
  *	@file: file in question
- *	@inode: file->f_path.dentry->d_inode
+ *	@inode: its inode
  *
  *	Frees the structures associated with sequential file; can be used
  *	as ->f_op->release() if you don't have private data to destroy.

include/linux/fs.h

···
 	} f_u;
 	struct path		f_path;
 #define f_dentry	f_path.dentry
+	struct inode		*f_inode;	/* cached value */
 	const struct file_operations	*f_op;
 
 	/*
···
 
 static inline struct inode *file_inode(struct file *f)
 {
-	return f->f_path.dentry->d_inode;
+	return f->f_inode;
 }
 
 /*

include/linux/fs_struct.h

···
 extern struct kmem_cache *fs_cachep;
 
 extern void exit_fs(struct task_struct *);
-extern void set_fs_root(struct fs_struct *, struct path *);
-extern void set_fs_pwd(struct fs_struct *, struct path *);
+extern void set_fs_root(struct fs_struct *, const struct path *);
+extern void set_fs_pwd(struct fs_struct *, const struct path *);
 extern struct fs_struct *copy_fs_struct(struct fs_struct *);
 extern void free_fs_struct(struct fs_struct *);
 extern int unshare_fs_struct(void);

include/linux/path.h

···
 	struct dentry *dentry;
 };
 
-extern void path_get(struct path *);
-extern void path_put(struct path *);
+extern void path_get(const struct path *);
+extern void path_put(const struct path *);
 
 static inline int path_equal(const struct path *path1, const struct path *path2)
 {

include/net/9p/client.h

···
 	void *rdir;
 
 	struct list_head flist;
-	struct list_head dlist;	/* list of all fids attached to a dentry */
+	struct hlist_node dlist;	/* list of all fids attached to a dentry */
 };
 
 /**

kernel/futex.c

···
  * Returns a negative error code or 0
  * The key words are stored in *key on success.
  *
- * For shared mappings, it's (page->index, vma->vm_file->f_path.dentry->d_inode,
+ * For shared mappings, it's (page->index, file_inode(vma->vm_file),
  * offset_within_page).  For private mappings, it's (uaddr, current->mm).
  * We can usually work out the index without swapping in the page.
  *

mm/shmem.c

···
 	inode->i_size = size;
 	clear_nlink(inode);	/* It is unlinked */
 #ifndef CONFIG_MMU
-	error = ramfs_nommu_expand_for_mapping(inode, size);
-	res = ERR_PTR(error);
-	if (error)
+	res = ERR_PTR(ramfs_nommu_expand_for_mapping(inode, size));
+	if (IS_ERR(res))
 		goto put_dentry;
 #endif
 

security/selinux/hooks.c

···
 
 	switch (cmd) {
 	case F_SETFL:
-		if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
-			err = -EINVAL;
-			break;
-		}
-
 		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
 			err = file_has_perm(cred, file, FILE__WRITE);
 			break;
···
 	case F_SETLK64:
 	case F_SETLKW64:
 #endif
-		if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
-			err = -EINVAL;
-			break;
-		}
 		err = file_has_perm(cred, file, FILE__LOCK);
 		break;
 	}