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Commit 6ca9f3ba authored by Jeff Layton's avatar Jeff Layton
Browse files

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: default avatarJeff Layton <jlayton@redhat.com>
Reviewed-and-Tested-by: default avatarSuresh Jayaraman <sjayaraman@suse.de>
parent 2422f676

fs/cifs/dir.c

+27 −8
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/slab.h>

#include <linux/namei.h>

#include <linux/mount.h>

#include <linux/file.h>

#include "cifsfs.h"

#include "cifspdu.h"

#include "cifsglob.h"
@@ -184,6 +185,8 @@ cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle, 
	}

	write_unlock(&GlobalSMBSeslock);



	file->private_data = pCifsFile;



	return pCifsFile;

}
@@ -463,14 +466,22 @@ cifs_create_set_dentry: 


	if (newinode && nd && (nd->flags & LOOKUP_OPEN)) {

		struct cifsFileInfo *pfile_info;

		/*

		 * cifs_fill_filedata() takes care of setting cifsFileInfo

		 * pointer to file->private_data.

		 */

		pfile_info = cifs_new_fileinfo(newinode, fileHandle, NULL,

		struct file *filp;



		filp = lookup_instantiate_filp(nd, direntry, generic_file_open);

		if (IS_ERR(filp)) {

			rc = PTR_ERR(filp);

			CIFSSMBClose(xid, tcon, fileHandle);

			goto cifs_create_out;

		}



		pfile_info = cifs_new_fileinfo(newinode, fileHandle, filp,

					       nd->path.mnt, oflags);

		if (pfile_info == NULL)

		if (pfile_info == NULL) {

			fput(filp);

			CIFSSMBClose(xid, tcon, fileHandle);

			rc = -ENOMEM;

		}

	} else {

		CIFSSMBClose(xid, tcon, fileHandle);

	}
@@ -717,15 +728,23 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, 
			direntry->d_op = &cifs_dentry_ops;

		d_add(direntry, newInode);

		if (posix_open) {

			cfile = cifs_new_fileinfo(newInode, fileHandle, NULL,

			filp = lookup_instantiate_filp(nd, direntry,

						       generic_file_open);

			if (IS_ERR(filp)) {

				rc = PTR_ERR(filp);

				CIFSSMBClose(xid, pTcon, fileHandle);

				goto lookup_out;

			}



			cfile = cifs_new_fileinfo(newInode, fileHandle, filp,

						  nd->path.mnt,

						  nd->intent.open.flags);

			if (cfile == NULL) {

				fput(filp);

				CIFSSMBClose(xid, pTcon, fileHandle);

				rc = -ENOMEM;

				goto lookup_out;

			}

			filp = lookup_instantiate_filp(nd, direntry, NULL);

		}

		/* since paths are not looked up by component - the parent

		   directories are presumed to be good here */

fs/cifs/file.c

+2 −42
Original line number Diff line number Diff line
@@ -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;

	}