Commit 4a7d2729 authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

smb: client: fix atomic open with O_DIRECT & O_SYNC 



When user application requests O_DIRECT|O_SYNC along with O_CREAT on
open(2), CREATE_NO_BUFFER and CREATE_WRITE_THROUGH bits were missed in
CREATE request when performing an atomic open, thus leading to
potentially data integrity issues.

Fix this by setting those missing bits in CREATE request when
O_DIRECT|O_SYNC has been specified in cifs_do_create().

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarPaulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarHenrique Carvalho <henrique.carvalho@suse.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 1f318b96

fs/smb/client/cifsglob.h

+11 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/utsname.h>

#include <linux/sched/mm.h>

#include <linux/netfs.h>

#include <linux/fcntl.h>

#include "cifs_fs_sb.h"

#include "cifsacl.h"

#include <crypto/internal/hash.h>
@@ -2375,4 +2376,14 @@ static inline bool cifs_forced_shutdown(const struct cifs_sb_info *sbi) 
	return cifs_sb_flags(sbi) & CIFS_MOUNT_SHUTDOWN;

}



static inline int cifs_open_create_options(unsigned int oflags, int opts)

{

	/* O_SYNC also has bit for O_DSYNC so following check picks up either */

	if (oflags & O_SYNC)

		opts |= CREATE_WRITE_THROUGH;

	if (oflags & O_DIRECT)

		opts |= CREATE_NO_BUFFER;

	return opts;

}



#endif	/* _CIFS_GLOB_H */

fs/smb/client/dir.c

+1 −0
Original line number Diff line number Diff line
@@ -308,6 +308,7 @@ static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned 
		goto out;

	}



	create_options |= cifs_open_create_options(oflags, create_options);

	/*

	 * if we're not using unix extensions, see if we need to set

	 * ATTR_READONLY on the create call

fs/smb/client/file.c

+3 −15
Original line number Diff line number Diff line
@@ -584,15 +584,8 @@ static int cifs_nt_open(const char *full_path, struct inode *inode, struct cifs_ 
 *********************************************************************/



	disposition = cifs_get_disposition(f_flags);



	/* BB pass O_SYNC flag through on file attributes .. BB */



	/* O_SYNC also has bit for O_DSYNC so following check picks up either */

	if (f_flags & O_SYNC)

		create_options |= CREATE_WRITE_THROUGH;



	if (f_flags & O_DIRECT)

		create_options |= CREATE_NO_BUFFER;

	create_options |= cifs_open_create_options(f_flags, create_options);



retry_open:

	oparms = (struct cifs_open_parms) {
@@ -1314,13 +1307,8 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush) 
		rdwr_for_fscache = 1;



	desired_access = cifs_convert_flags(cfile->f_flags, rdwr_for_fscache);



	/* O_SYNC also has bit for O_DSYNC so following check picks up either */

	if (cfile->f_flags & O_SYNC)

		create_options |= CREATE_WRITE_THROUGH;



	if (cfile->f_flags & O_DIRECT)

		create_options |= CREATE_NO_BUFFER;

	create_options |= cifs_open_create_options(cfile->f_flags,

						   create_options);



	if (server->ops->get_lease_key)

		server->ops->get_lease_key(inode, &cfile->fid);