Re: [PATCH v4 3/7] CIFS: Add O_DENY* open flags support

[Pavel Shilovsky]

2013/4/8 Jeff Layton :
> On Fri,  5 Apr 2013 20:57:51 +0400
> Pavel Shilovsky  wrote:
> > Construct share_access value from O_DENY* flags and send it to
> > the server.
> > Signed-off-by: Pavel Shilovsky
> >
> > fs/cifs/cifsglob.h | 16 +++++++++++++++-
> >  fs/cifs/dir.c      |  3 +++
> >  fs/cifs/file.c     |  4 ++++
> >  fs/locks.c         |  8 ++++++++
> >  4 files changed, 30 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> > index cd4bbf3..7e876b9 100644
> > --- a/fs/cifs/cifsglob.h
> > +++ b/fs/cifs/cifsglob.h
> > @@ -465,7 +465,7 @@ struct smb_vol {
> >                        CIFS_MOUNT_CIFS_BACKUPUID | CIFS_MOUNT_CIFS_BACKUPGID)
> >
> > #define CIFS_MS_MASK (MS_RDONLY | MS_MANDLOCK | MS_NOEXEC | MS_NOSUID | \
> > -
> >               MS_NODEV | MS_SYNCHRONOUS)
> > -
> >               MS_NODEV | MS_SYNCHRONOUS | MS_SHARELOCK)
> >
> > struct cifs_mnt_data {
> >       struct cifs_sb_info *cifs_sb;
> > @@ -947,6 +947,20 @@ struct cifsFileInfo {
> >       struct work_struct oplock_break; /* work for oplock breaks */
> >  };
> >
> > +static inline int
> > +cifs_get_share_flags(unsigned int flags)
> > +{
> > -
> > int share_access = 0;
> > -
> > -
> > if (!(flags & O_DENYREAD))
> > -
> >         share_access |= FILE_SHARE_READ;
> > -
> > if (!(flags & O_DENYWRITE))
> > -
> >         share_access |= FILE_SHARE_WRITE;
> > -
> > if (!(flags & O_DENYDELETE))
> > -
> >         share_access |= FILE_SHARE_DELETE;
> > -
> > return share_access;
> >
> > +}
> > -
> >
> > struct cifs_io_parms {
> >       __u16 netfid;
> >  #ifdef CONFIG_CIFS_SMB2
> > diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
> > index 267b608..d4331de 100644
> > --- a/fs/cifs/dir.c
> > +++ b/fs/cifs/dir.c
> > @@ -294,6 +294,9 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
> >       else
> >               cFYI(1, "Create flag not set in create function");
> > -
> > if (IS_SHARELOCK(inode))
> > -
> >         share_access = cifs_get_share_flags(oflags);
> > -
> > /*
> >  * BB add processing to set equivalent of mode - e.g. via CreateX with
> >  * ACLs
> >
> > diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> > index 0d524a7..9394b2b 100644
> > --- a/fs/cifs/file.c
> > +++ b/fs/cifs/file.c
> > @@ -210,6 +210,8 @@ cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
> >   *********************************************************************/
> >   disposition = cifs_get_disposition(f_flags);
> > -
> > if (IS_SHARELOCK(inode))
> > -
> >         share_access = cifs_get_share_flags(f_flags);
> >
> > /* BB pass O_SYNC flag through on file attributes .. BB */
> >
> > @@ -645,6 +647,8 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
> >       }
> >   desired_access = cifs_convert_flags(cfile->f_flags);
> > -
> > if (IS_SHARELOCK(inode))
> > -
> >         share_access = cifs_get_share_flags(cfile->f_flags);
> >
> > if (backup_cred(cifs_sb))
> >         create_options |= CREATE_OPEN_BACKUP_INTENT;
> >
> > diff --git a/fs/locks.c b/fs/locks.c
> > index 1eccc75..2184ddd 100644
> > --- a/fs/locks.c
> > +++ b/fs/locks.c
> > @@ -846,10 +846,18 @@ deny_lock_file(struct file *filp)
> >  {
> >       struct file_lock *lock;
> >       int error = 0;
> > -
> > const char *fsname = filp->f_path.dentry->d_inode->i_sb->s_type->name;
> >
> > if (!IS_SHARELOCK(filp->f_path.dentry->d_inode))
> >         return error;
> >
> > -
> > /*
> > -
> >  * Don't set a lock on CIFS file systems because they can process it
> > -
> >  * themselves.
> > -
> >  */
> > -
> > if (!strncmp(fsname, "cifs", 4))
> > -
> >         return error;
> > -
>
> NAK....
>
> This is really nasty. Instead of doing this, you should instead create
> a new file_system_type->fs_flags value. Then, set that flag for cifs
> and nfs4, and test it here.

It seems I missed this fs_flags opportunity. Thank you for pointing it
out - I will fix and repost.

--
Best regards,
Pavel Shilovsky.