cifs: keep dentry reference in cifsFileInfo instead of inode reference

cifsFileInfo is a bit problematic. It contains a reference back to the
struct file itself. This makes it difficult for a cifsFileInfo to exist
without a corresponding struct file.

It would be better instead of the cifsFileInfo just held info pertaining
to the open file on the server instead without any back refrences to the
struct file. This would allow it to exist after the filp to which it was
originally attached was closed.

Much of the use of the file pointer in this struct is to get at the
dentry.  Begin divorcing the cifsFileInfo from the struct file by
keeping a reference to the dentry. Since the dentry will have a
reference to the inode, we can eliminate the "pInode" field too and
convert the igrab/iput to dget/dput.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index e249b561ce8f..6887c412c61a 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -135,6 +135,7 @@ cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle, struct file *file,
                   struct vfsmount *mnt, struct tcon_link *tlink,
                   unsigned int oflags, __u32 oplock)
 {
+        struct dentry *dentry = file->f_path.dentry;
         struct cifsFileInfo *pCifsFile;
         struct cifsInodeInfo *pCifsInode;
 
@@ -145,7 +146,7 @@ cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle, struct file *file,
         pCifsFile->netfid = fileHandle;
         pCifsFile->pid = current->tgid;
         pCifsFile->uid = current_fsuid();
-        pCifsFile->pInode = igrab(newinode);
+        pCifsFile->dentry = dget(dentry);
         pCifsFile->mnt = mnt;
         pCifsFile->pfile = file;
         pCifsFile->invalidHandle = false;