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)

26 files changed, 108 insertions, 171 deletions

diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
index 280ded8b79ba..8538015ed4a0 100644
--- a/arch/s390/hypfs/inode.c
+++ b/arch/s390/hypfs/inode.c
@@ -171,12 +171,10 @@ static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov,
                               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
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index 4929502c1372..ce130493b802 100644
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -71,7 +71,7 @@ static ssize_t msr_read(struct file *file, char __user *buf,
         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;
 
@@ -99,7 +99,7 @@ static ssize_t msr_write(struct file *file, const char __user *buf,
         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;
 
@@ -125,7 +125,7 @@ static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg)
 {
         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) {
@@ -171,13 +171,12 @@ static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg)
 
 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 */
 
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 195d56d8a1ee..e336b281b847 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -580,7 +580,7 @@ static int do_devinfo_ioctl(struct comedi_device *dev,
                             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;
@@ -1615,7 +1615,7 @@ static int do_poll_ioctl(struct comedi_device *dev, unsigned int arg,
 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;
@@ -1743,7 +1743,7 @@ static struct vm_operations_struct comedi_vm_ops = {
 
 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;
@@ -1823,7 +1823,7 @@ done:
 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;
@@ -1869,7 +1869,7 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
         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);
 
@@ -1964,7 +1964,7 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes,
         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);
 
@@ -2133,7 +2133,7 @@ ok:
 
 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)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index fd473639ab70..05400acbc456 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -960,11 +960,10 @@ static ssize_t tty_read(struct file *file, char __user *buf, size_t count,
                         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;
@@ -1132,12 +1131,11 @@ void tty_write_message(struct tty_struct *tty, char *msg)
 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)))
@@ -2047,7 +2045,7 @@ static unsigned int tty_poll(struct file *filp, poll_table *wait)
         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);
@@ -2063,7 +2061,7 @@ static int __tty_fasync(int fd, struct file *filp, int on)
         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);
@@ -2637,9 +2635,8 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
         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);
@@ -2780,12 +2777,11 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 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) {
diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index afd4724b2d92..d51ec9fafcc8 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 bb0b6e7f58fc..2b6787fcb626 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 9ad68628522c..f039b104a98e 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 b5340c829de1..d86edc8d3fd0 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 61e4fa70a6fa..53687bbf2296 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 c541ab8b64dd..b505a145a593 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 b7a053d4c6d3..958a46da19ae 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 aa07d3684a2e..cd4d87a82951 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 fe6ca583bbc0..d8ac61d0c932 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 e9bdec0b16d9..11dfa0c3fb46 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 c8071768b950..34b80ba95bad 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 2f6af7f645eb..507141fceb99 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 dc984fee5532..961bc1268366 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 e3441f58d2e1..68354466879f 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 15c6304bab71..38bb59f3f2ad 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.
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4e686a099465..74a907b8b950 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -769,6 +769,7 @@ struct file {
         } f_u;
         struct path             f_path;
 #define f_dentry        f_path.dentry
+        struct inode            *f_inode;       /* cached value */
         const struct file_operations    *f_op;
 
         /*
@@ -2217,7 +2218,7 @@ static inline bool execute_ok(struct inode *inode)
 
 static inline struct inode *file_inode(struct file *f)
 {
-        return f->f_path.dentry->d_inode;
+        return f->f_inode;
 }
 
 /*
diff --git a/include/linux/fs_struct.h b/include/linux/fs_struct.h
index d0ae3a84bcfb..729eded4b24f 100644
--- a/include/linux/fs_struct.h
+++ b/include/linux/fs_struct.h
@@ -17,8 +17,8 @@ struct fs_struct {
 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);
diff --git a/include/linux/path.h b/include/linux/path.h
index edc98dec6266..d1372186f431 100644
--- a/include/linux/path.h
+++ b/include/linux/path.h
@@ -9,8 +9,8 @@ struct path {
         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)
 {
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index 5ff70f433e87..4c7c01a73911 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -192,7 +192,7 @@ struct p9_fid {
         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 */
 };
 
 /**
diff --git a/kernel/futex.c b/kernel/futex.c
index fbc07a29ec53..f0090a993dab 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -226,7 +226,7 @@ static void drop_futex_key_refs(union futex_key *key)
  * 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.
  *
diff --git a/mm/shmem.c b/mm/shmem.c
index ed2befb4952e..1c44af71fcf5 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2932,9 +2932,8 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
         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
 
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 84b591711eec..2fa28c88900c 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3135,11 +3135,6 @@ static int selinux_file_fcntl(struct file *file, unsigned int cmd,
 
         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;
@@ -3162,10 +3157,6 @@ static int selinux_file_fcntl(struct file *file, unsigned int cmd,
         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;
         }