1 files changed, 29 insertions, 6 deletions

diff --git a/fs/open.c b/fs/open.c
index 48afc5c139d2..14a51de01f54 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -669,11 +669,16 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
                                         int (*open)(struct inode *, struct file *),
                                         const struct cred *cred)
 {
+        static const struct file_operations empty_fops = {};
         struct inode *inode;
         int error;
 
         f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK |
                                 FMODE_PREAD | FMODE_PWRITE;
+
+        if (unlikely(f->f_flags & O_PATH))
+                f->f_mode = FMODE_PATH;
+
         inode = dentry->d_inode;
         if (f->f_mode & FMODE_WRITE) {
                 error = __get_file_write_access(inode, mnt);
@@ -687,9 +692,15 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
         f->f_path.dentry = dentry;
         f->f_path.mnt = mnt;
         f->f_pos = 0;
-        f->f_op = fops_get(inode->i_fop);
         file_sb_list_add(f, inode->i_sb);
 
+        if (unlikely(f->f_mode & FMODE_PATH)) {
+                f->f_op = &empty_fops;
+                return f;
+        }
+
+        f->f_op = fops_get(inode->i_fop);
+
         error = security_dentry_open(f, cred);
         if (error)
                 goto cleanup_all;
@@ -911,9 +922,18 @@ static inline int build_open_flags(int flags, int mode, struct open_flags *op)
         if (flags & __O_SYNC)
                 flags |= O_DSYNC;
 
-        op->open_flag = flags;
+        /*
+         * If we have O_PATH in the open flag. Then we
+         * cannot have anything other than the below set of flags
+         */
+        if (flags & O_PATH) {
+                flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH;
+                acc_mode = 0;
+        } else {
+                acc_mode = MAY_OPEN | ACC_MODE(flags);
+        }
 
-        acc_mode = MAY_OPEN | ACC_MODE(flags);
+        op->open_flag = flags;
 
         /* O_TRUNC implies we need access checks for write permissions */
         if (flags & O_TRUNC)
@@ -926,7 +946,8 @@ static inline int build_open_flags(int flags, int mode, struct open_flags *op)
 
         op->acc_mode = acc_mode;
 
-        op->intent = LOOKUP_OPEN;
+        op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN;
+
         if (flags & O_CREAT) {
                 op->intent |= LOOKUP_CREATE;
                 if (flags & O_EXCL)
@@ -1053,8 +1074,10 @@ int filp_close(struct file *filp, fl_owner_t id)
         if (filp->f_op && filp->f_op->flush)
                 retval = filp->f_op->flush(filp, id);
 
-        dnotify_flush(filp, id);
-        locks_remove_posix(filp, id);
+        if (likely(!(filp->f_mode & FMODE_PATH))) {
+                dnotify_flush(filp, id);
+                locks_remove_posix(filp, id);
+        }
         fput(filp);
         return retval;
 }