cifs: pass instantiated filp back after open call

The current scheme of sticking open files on a list and assuming that
cifs_open will scoop them off of it is broken and leads to "Busy
inodes after umount..." errors at unmount time.

The problem is that there is no guarantee that cifs_open will always
be called after a ->lookup or ->create operation. If there are
permissions or other problems, then it's quite likely that it *won't*
be called.

Fix this by fully instantiating the filp whenever the file is created
and pass that filp back to the VFS. If there is a problem, the VFS
can clean up the references.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>

1 files changed, 2 insertions, 42 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 542e0c874d64..9cbf0f097a39 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -162,38 +162,6 @@ psx_client_can_cache:
 	return 0;
 }
 
-static struct cifsFileInfo *
-cifs_fill_filedata(struct file *file)
-{
-	struct list_head *tmp;
-	struct cifsFileInfo *pCifsFile = NULL;
-	struct cifsInodeInfo *pCifsInode = NULL;
-
-	/* search inode for this file and fill in file->private_data */
-	pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
-	read_lock(&GlobalSMBSeslock);
-	list_for_each(tmp, &pCifsInode->openFileList) {
-		pCifsFile = list_entry(tmp, struct cifsFileInfo, flist);
-		if ((pCifsFile->pfile == NULL) &&
-		    (pCifsFile->pid == current->tgid)) {
-			/* mode set in cifs_create */
-
-			/* needed for writepage */
-			pCifsFile->pfile = file;
-			file->private_data = pCifsFile;
-			break;
-		}
-	}
-	read_unlock(&GlobalSMBSeslock);
-
-	if (file->private_data != NULL) {
-		return pCifsFile;
-	} else if ((file->f_flags & O_CREAT) && (file->f_flags & O_EXCL))
-			cERROR(1, "could not find file instance for "
-				   "new file %p", file);
-	return NULL;
-}
-
 /* all arguments to this function must be checked for validity in caller */
 static inline int cifs_open_inode_helper(struct inode *inode, struct file *file,
 	struct cifsInodeInfo *pCifsInode, struct cifsFileInfo *pCifsFile,
@@ -256,7 +224,7 @@ int cifs_open(struct inode *inode, struct file *file)
 	__u32 oplock;
 	struct cifs_sb_info *cifs_sb;
 	struct cifsTconInfo *tcon;
-	struct cifsFileInfo *pCifsFile;
+	struct cifsFileInfo *pCifsFile = NULL;
 	struct cifsInodeInfo *pCifsInode;
 	char *full_path = NULL;
 	int desiredAccess;
@@ -270,12 +238,6 @@ int cifs_open(struct inode *inode, struct file *file)
 	tcon = cifs_sb->tcon;
 
 	pCifsInode = CIFS_I(file->f_path.dentry->d_inode);
-	pCifsFile = cifs_fill_filedata(file);
-	if (pCifsFile) {
-		rc = 0;
-		FreeXid(xid);
-		return rc;
-	}
 
 	full_path = build_path_from_dentry(file->f_path.dentry);
 	if (full_path == NULL) {
@@ -315,7 +277,6 @@ int cifs_open(struct inode *inode, struct file *file)
 				rc = -ENOMEM;
 				goto out;
 			}
-			file->private_data = pCifsFile;
 
 			cifs_posix_open_inode_helper(inode, file, pCifsInode,
 						     oplock, netfid);
@@ -401,8 +362,7 @@ int cifs_open(struct inode *inode, struct file *file)
 
 	pCifsFile = cifs_new_fileinfo(inode, netfid, file, file->f_path.mnt,
 					file->f_flags);
-	file->private_data = pCifsFile;
-	if (file->private_data == NULL) {
+	if (pCifsFile == NULL) {
 		rc = -ENOMEM;
 		goto out;
 	}