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)

Author: torvalds

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

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 */
 

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 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
 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 @@ static int comedi_open(struct inode *inode, struct file *file)
 
 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

@@ -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) {

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;

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

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)