1 files changed, 31 insertions, 19 deletions

diff --git a/fs/pipe.c b/fs/pipe.c
index b1626f269a34..f8b6bdcb879a 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -222,7 +222,7 @@ pipe_read(struct kiocb *iocb, const struct iovec *_iov,
 	   unsigned long nr_segs, loff_t pos)
 {
 	struct file *filp = iocb->ki_filp;
-	struct inode *inode = filp->f_dentry->d_inode;
+	struct inode *inode = filp->f_path.dentry->d_inode;
 	struct pipe_inode_info *pipe;
 	int do_wakeup;
 	ssize_t ret;
@@ -335,7 +335,7 @@ pipe_write(struct kiocb *iocb, const struct iovec *_iov,
 	    unsigned long nr_segs, loff_t ppos)
 {
 	struct file *filp = iocb->ki_filp;
-	struct inode *inode = filp->f_dentry->d_inode;
+	struct inode *inode = filp->f_path.dentry->d_inode;
 	struct pipe_inode_info *pipe;
 	ssize_t ret;
 	int do_wakeup;
@@ -520,7 +520,7 @@ static int
 pipe_ioctl(struct inode *pino, struct file *filp,
 	   unsigned int cmd, unsigned long arg)
 {
-	struct inode *inode = filp->f_dentry->d_inode;
+	struct inode *inode = filp->f_path.dentry->d_inode;
 	struct pipe_inode_info *pipe;
 	int count, buf, nrbufs;
 
@@ -548,7 +548,7 @@ static unsigned int
 pipe_poll(struct file *filp, poll_table *wait)
 {
 	unsigned int mask;
-	struct inode *inode = filp->f_dentry->d_inode;
+	struct inode *inode = filp->f_path.dentry->d_inode;
 	struct pipe_inode_info *pipe = inode->i_pipe;
 	int nrbufs;
 
@@ -601,7 +601,7 @@ pipe_release(struct inode *inode, int decr, int decw)
 static int
 pipe_read_fasync(int fd, struct file *filp, int on)
 {
-	struct inode *inode = filp->f_dentry->d_inode;
+	struct inode *inode = filp->f_path.dentry->d_inode;
 	int retval;
 
 	mutex_lock(&inode->i_mutex);
@@ -618,7 +618,7 @@ pipe_read_fasync(int fd, struct file *filp, int on)
 static int
 pipe_write_fasync(int fd, struct file *filp, int on)
 {
-	struct inode *inode = filp->f_dentry->d_inode;
+	struct inode *inode = filp->f_path.dentry->d_inode;
 	int retval;
 
 	mutex_lock(&inode->i_mutex);
@@ -635,7 +635,7 @@ pipe_write_fasync(int fd, struct file *filp, int on)
 static int
 pipe_rdwr_fasync(int fd, struct file *filp, int on)
 {
-	struct inode *inode = filp->f_dentry->d_inode;
+	struct inode *inode = filp->f_path.dentry->d_inode;
 	struct pipe_inode_info *pipe = inode->i_pipe;
 	int retval;
 
@@ -830,7 +830,14 @@ void free_pipe_info(struct inode *inode)
 static struct vfsmount *pipe_mnt __read_mostly;
 static int pipefs_delete_dentry(struct dentry *dentry)
 {
-	return 1;
+	/*
+	 * At creation time, we pretended this dentry was hashed
+	 * (by clearing DCACHE_UNHASHED bit in d_flags)
+	 * At delete time, we restore the truth : not hashed.
+	 * (so that dput() can proceed correctly)
+	 */
+	dentry->d_flags |= DCACHE_UNHASHED;
+	return 0;
 }
 
 static struct dentry_operations pipefs_dentry_operations = {
@@ -891,19 +898,24 @@ struct file *create_write_pipe(void)
 	if (!inode)
 		goto err_file;
 
-	sprintf(name, "[%lu]", inode->i_ino);
+	this.len = sprintf(name, "[%lu]", inode->i_ino);
 	this.name = name;
-	this.len = strlen(name);
-	this.hash = inode->i_ino; /* will go */
+	this.hash = 0;
 	err = -ENOMEM;
 	dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &this);
 	if (!dentry)
 		goto err_inode;
 
 	dentry->d_op = &pipefs_dentry_operations;
-	d_add(dentry, inode);
-	f->f_vfsmnt = mntget(pipe_mnt);
-	f->f_dentry = dentry;
+	/*
+	 * We dont want to publish this dentry into global dentry hash table.
+	 * We pretend dentry is already hashed, by unsetting DCACHE_UNHASHED
+	 * This permits a working /proc/$pid/fd/XXX on pipes
+	 */
+	dentry->d_flags &= ~DCACHE_UNHASHED;
+	d_instantiate(dentry, inode);
+	f->f_path.mnt = mntget(pipe_mnt);
+	f->f_path.dentry = dentry;
 	f->f_mapping = inode->i_mapping;
 
 	f->f_flags = O_WRONLY;
@@ -923,8 +935,8 @@ struct file *create_write_pipe(void)
 
 void free_write_pipe(struct file *f)
 {
-	mntput(f->f_vfsmnt);
-	dput(f->f_dentry);
+	mntput(f->f_path.mnt);
+	dput(f->f_path.dentry);
 	put_filp(f);
 }
 
@@ -935,9 +947,9 @@ struct file *create_read_pipe(struct file *wrf)
 		return ERR_PTR(-ENFILE);
 
 	/* Grab pipe from the writer */
-	f->f_vfsmnt = mntget(wrf->f_vfsmnt);
-	f->f_dentry = dget(wrf->f_dentry);
-	f->f_mapping = wrf->f_dentry->d_inode->i_mapping;
+	f->f_path.mnt = mntget(wrf->f_path.mnt);
+	f->f_path.dentry = dget(wrf->f_path.dentry);
+	f->f_mapping = wrf->f_path.dentry->d_inode->i_mapping;
 
 	f->f_pos = 0;
 	f->f_flags = O_RDONLY;