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)

15 files changed, 79 insertions, 126 deletions

diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index afd4724..d51ec9f 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -41,29 +41,16 @@
  *
  */
 
-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;
-
-	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);
+	hlist_add_head(&fid->dlist, (struct hlist_head *)&dentry->d_fsdata);
+}
 
-	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);
 }
 
 /**
@@ -76,23 +63,23 @@ int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid)
 
 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;
@@ -215,8 +202,17 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
 	}
 	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;
diff --git a/fs/9p/fid.h b/fs/9p/fid.h
index bb0b6e7..2b6787f 100644
--- a/fs/9p/fid.h
+++ b/fs/9p/fid.h
@@ -23,28 +23,8 @@
 #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
diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c
index 9ad6862..f039b10 100644
--- a/fs/9p/vfs_dentry.c
+++ b/fs/9p/vfs_dentry.c
@@ -83,21 +83,12 @@ static int v9fs_cached_dentry_delete(const struct dentry *dentry)
 
 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)
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index b5340c8..d86edc8 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -692,9 +692,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 				   "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;
@@ -790,7 +788,6 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 	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);
@@ -808,13 +805,11 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 	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
@@ -826,14 +821,9 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 	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
@@ -842,15 +832,13 @@ inst_out:
 	 * 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
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 61e4fa7..53687bb 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -333,9 +333,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
 	/* 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);
@@ -453,12 +451,11 @@ static int v9fs_vfs_mkdir_dotl(struct inode *dir,
 				 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
@@ -747,11 +744,10 @@ v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
 				 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);
@@ -900,11 +896,10 @@ v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
 			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.
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index c541ab8..b505a14 100644
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -1606,7 +1606,7 @@ err:
 
 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;
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index b7a053d..958a46d 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -29,7 +29,7 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
 						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;
@@ -544,7 +544,7 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
 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))
@@ -577,7 +577,7 @@ static inline __u32 f2fs_mask_flags(umode_t mode, __u32 flags)
 
 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;
diff --git a/fs/file_table.c b/fs/file_table.c
index aa07d36..cd4d87a 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -176,6 +176,7 @@ struct file *alloc_file(struct path *path, fmode_t mode,
 		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;
@@ -258,6 +259,7 @@ static void __fput(struct file *file)
 		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);
diff --git a/fs/fs_struct.c b/fs/fs_struct.c
index fe6ca58..d8ac61d 100644
--- a/fs/fs_struct.c
+++ b/fs/fs_struct.c
@@ -10,7 +10,7 @@
  * 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;
 
@@ -29,7 +29,7 @@ void set_fs_root(struct fs_struct *fs, struct path *path)
  * 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;
 
@@ -53,7 +53,7 @@ static inline int replace_path(struct path *p, const struct path *old, const str
 	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;
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index e9bdec0..11dfa0c 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -532,7 +532,7 @@ void fuse_request_send_background_locked(struct fuse_conn *fc,
 
 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;
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index c807176..34b80ba 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -355,7 +355,7 @@ static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index)
 
 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;
@@ -1215,7 +1215,7 @@ static ssize_t __fuse_direct_read(struct file *file, const struct iovec *iov,
 				  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;
@@ -1238,7 +1238,7 @@ static ssize_t fuse_direct_read(struct file *file, char __user *buf,
 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;
 
@@ -1258,7 +1258,7 @@ static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
 				 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))
@@ -1485,7 +1485,7 @@ static const struct vm_operations_struct fuse_file_vm_ops = {
 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;
@@ -1543,7 +1543,7 @@ static void fuse_lk_fill(struct fuse_req *req, struct file *file,
 			 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;
@@ -1565,7 +1565,7 @@ static void fuse_lk_fill(struct fuse_req *req, struct file *file,
 
 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;
@@ -1590,7 +1590,7 @@ static int fuse_getlk(struct file *file, struct file_lock *fl)
 
 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;
@@ -1622,7 +1622,7 @@ static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
 
 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;
 
@@ -1645,7 +1645,7 @@ static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
 
 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;
 
@@ -1702,7 +1702,7 @@ static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
 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)
@@ -2079,7 +2079,7 @@ EXPORT_SYMBOL_GPL(fuse_do_ioctl);
 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))
diff --git a/fs/internal.h b/fs/internal.h
index 2f6af7f..507141f 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -69,7 +69,7 @@ extern void __mnt_drop_write_file(struct file *);
 /*
  * 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
diff --git a/fs/namei.c b/fs/namei.c
index dc984fe..961bc12 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -451,7 +451,7 @@ int inode_permission(struct inode *inode, int mask)
  *
  * 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);
@@ -464,7 +464,7 @@ EXPORT_SYMBOL(path_get);
  *
  * 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);
diff --git a/fs/open.c b/fs/open.c
index e3441f5..6835446 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -704,7 +704,7 @@ static int do_dentry_open(struct file *f,
 		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)
@@ -767,6 +767,7 @@ cleanup_file:
 	path_put(&f->f_path);
 	f->f_path.mnt = NULL;
 	f->f_path.dentry = NULL;
+	f->f_inode = NULL;
 	return error;
 }
 
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 15c6304..38bb59f 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -339,7 +339,7 @@ EXPORT_SYMBOL(seq_lseek);
 /**
  *	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.