Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...

1 files changed, 36 insertions, 25 deletions

diff --git a/fs/open.c b/fs/open.c
index e0250bdcc440..e33dab287fa0 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -51,8 +51,10 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
                 newattrs.ia_valid |= ATTR_FILE;
         }
 
-        /* Remove suid/sgid on truncate too */
-        ret = should_remove_suid(dentry);
+        /* Remove suid, sgid, and file capabilities on truncate too */
+        ret = dentry_needs_remove_privs(dentry);
+        if (ret < 0)
+                return ret;
         if (ret)
                 newattrs.ia_valid |= ret | ATTR_FORCE;
 
@@ -678,18 +680,18 @@ int open_check_o_direct(struct file *f)
 }
 
 static int do_dentry_open(struct file *f,
+                          struct inode *inode,
                           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;
 
         path_get(&f->f_path);
-        inode = f->f_inode = f->f_path.dentry->d_inode;
+        f->f_inode = inode;
         f->f_mapping = inode->i_mapping;
 
         if (unlikely(f->f_flags & O_PATH)) {
@@ -793,7 +795,8 @@ int finish_open(struct file *file, struct dentry *dentry,
         BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
 
         file->f_path.dentry = dentry;
-        error = do_dentry_open(file, open, current_cred());
+        error = do_dentry_open(file, d_backing_inode(dentry), open,
+                               current_cred());
         if (!error)
                 *opened |= FILE_OPENED;
 
@@ -822,6 +825,34 @@ int finish_no_open(struct file *file, struct dentry *dentry)
 }
 EXPORT_SYMBOL(finish_no_open);
 
+char *file_path(struct file *filp, char *buf, int buflen)
+{
+        return d_path(&filp->f_path, buf, buflen);
+}
+EXPORT_SYMBOL(file_path);
+
+/**
+ * vfs_open - open the file at the given path
+ * @path: path to open
+ * @file: newly allocated file with f_flag initialized
+ * @cred: credentials to use
+ */
+int vfs_open(const struct path *path, struct file *file,
+             const struct cred *cred)
+{
+        struct dentry *dentry = path->dentry;
+        struct inode *inode = dentry->d_inode;
+
+        file->f_path = *path;
+        if (dentry->d_flags & DCACHE_OP_SELECT_INODE) {
+                inode = dentry->d_op->d_select_inode(dentry, file->f_flags);
+                if (IS_ERR(inode))
+                        return PTR_ERR(inode);
+        }
+
+        return do_dentry_open(file, inode, NULL, cred);
+}
+
 struct file *dentry_open(const struct path *path, int flags,
                          const struct cred *cred)
 {
@@ -853,26 +884,6 @@ struct file *dentry_open(const struct path *path, int flags,
 }
 EXPORT_SYMBOL(dentry_open);
 
-/**
- * vfs_open - open the file at the given path
- * @path: path to open
- * @filp: newly allocated file with f_flag initialized
- * @cred: credentials to use
- */
-int vfs_open(const struct path *path, struct file *filp,
-             const struct cred *cred)
-{
-        struct inode *inode = path->dentry->d_inode;
-
-        if (inode->i_op->dentry_open)
-                return inode->i_op->dentry_open(path->dentry, filp, cred);
-        else {
-                filp->f_path = *path;
-                return do_dentry_open(filp, NULL, cred);
-        }
-}
-EXPORT_SYMBOL(vfs_open);
-
 static inline int build_open_flags(int flags, umode_t mode, struct open_flags *op)
 {
         int lookup_flags = 0;