Re: [PATCH] not overwriting file_lock structure after GET_LK

On Mon, 5 Apr 2010 09:59:14 +0400
[email protected] wrote:

> From: Pavel Shilovsky <[email protected]>
> 
> If we have preventing lock, cifs should overwrite file_lock structure
> with info about preventing lock. If we haven't preventing lock, cifs
> should leave it unchanged except for the lock type (change it to F_UNLCK).
> 
> Signed-off-by: Pavel Shilovsky <[email protected]>
> Reviewed-by: Jeff Layton <[email protected]>
> ---
>  fs/cifs/cifssmb.c |   15 ++++++++++++++-
>  fs/cifs/file.c    |   28 ++++++++++++++++++++++++++--
>  2 files changed, 40 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> index 7cc7f83..b3bbb2b 100644
> --- a/fs/cifs/cifssmb.c
> +++ b/fs/cifs/cifssmb.c
> @@ -1793,8 +1793,21 @@ CIFSSMBPosixLock(const int xid, struct cifsTconInfo *tcon,
>  		}
>  		parm_data = (struct cifs_posix_lock *)
>  			((char *)&pSMBr->hdr.Protocol + data_offset);
> -		if (parm_data->lock_type == cpu_to_le16(CIFS_UNLCK))
> +		if (parm_data->lock_type == __constant_cpu_to_le16(CIFS_UNLCK))
>  			pLockData->fl_type = F_UNLCK;
> +		else {
> +			if (parm_data->lock_type ==
> +					__constant_cpu_to_le16(CIFS_RDLCK))
> +				pLockData->fl_type = F_RDLCK;
> +			else if (parm_data->lock_type ==
> +					__constant_cpu_to_le16(CIFS_WRLCK))
> +				pLockData->fl_type = F_WRLCK;
> +
> +			pLockData->fl_start = parm_data->start;
> +			pLockData->fl_end = parm_data->start +
> +						parm_data->length - 1;
> +			pLockData->fl_pid = parm_data->pid;
> +		}
>  	}
>  
>  plk_err_exit:
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index ca2ba7a..d9e8650 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -838,8 +838,32 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
>  
>  		} else {
>  			/* if rc == ERR_SHARING_VIOLATION ? */
> -			rc = 0;	/* do not change lock type to unlock
> -				   since range in use */
> +			rc = 0;
> +
> +			if (lockType & LOCKING_ANDX_SHARED_LOCK) {
> +				pfLock->fl_type = F_WRLCK;
> +			} else {
> +				rc = CIFSSMBLock(xid, tcon, netfid, length,
> +					pfLock->fl_start, 0, 1,
> +					lockType | LOCKING_ANDX_SHARED_LOCK,
> +					0 /* wait flag */);
> +				if (rc == 0) {
> +					rc = CIFSSMBLock(xid, tcon, netfid,
> +						length, pfLock->fl_start, 1, 0,
> +						lockType |
> +						LOCKING_ANDX_SHARED_LOCK,
> +						0 /* wait flag */);
> +					pfLock->fl_type = F_RDLCK;
> +					if (rc != 0)
> +						cERROR(1, ("Error unlocking "
> +						"previously locked range %d "
> +						"during test of lock", rc));
> +					rc = 0;
> +				} else {
> +					pfLock->fl_type = F_WRLCK;
> +					rc = 0;
> +				}
> +			}
>  		}
>  
>  		FreeXid(xid);

Looks good -- thanks for sticking with this.

Reviewed-by: Jeff Layton <[email protected]>