[CIFS]

Allow Windows blocking locks to be cancelled via a
CANCEL_LOCK call. TODO - restrict this to servers
that support NT_STATUS codes (Win9x will probably
not support this call).

Signed-off-by: Jeremy Allison <jra@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
(cherry picked from 570d4d2d895569825d0d017d4e76b51138f68864 commit)

1 files changed, 80 insertions, 15 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 52e2e4c8794b..e9c5ba9084fc 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -5,6 +5,7 @@
  * 
  *   Copyright (C) International Business Machines  Corp., 2002,2003
  *   Author(s): Steve French (sfrench@us.ibm.com)
+ *              Jeremy Allison (jra@samba.org)
  *
  *   This library is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU Lesser General Public License as published
@@ -47,6 +48,8 @@ static inline struct cifsFileInfo *cifs_init_private(
         private_data->netfid = netfid;
         private_data->pid = current->tgid;      
         init_MUTEX(&private_data->fh_sem);
+        init_MUTEX(&private_data->lock_sem);
+        INIT_LIST_HEAD(&private_data->llist);
         private_data->pfile = file; /* needed for writepage */
         private_data->pInode = inode;
         private_data->invalidHandle = FALSE;
@@ -473,6 +476,8 @@ int cifs_close(struct inode *inode, struct file *file)
         cifs_sb = CIFS_SB(inode->i_sb);
         pTcon = cifs_sb->tcon;
         if (pSMBFile) {
+                struct cifsLockInfo *li, *tmp;
+
                 pSMBFile->closePend = TRUE;
                 if (pTcon) {
                         /* no sense reconnecting to close a file that is
@@ -496,6 +501,16 @@ int cifs_close(struct inode *inode, struct file *file)
                                                   pSMBFile->netfid);
                         }
                 }
+
+                /* Delete any outstanding lock records.
+                   We'll lose them when the file is closed anyway. */
+                down(&pSMBFile->lock_sem);
+                list_for_each_entry_safe(li, tmp, &pSMBFile->llist, llist) {
+                        list_del(&li->llist);
+                        kfree(li);
+                }
+                up(&pSMBFile->lock_sem);
+
                 write_lock(&GlobalSMBSeslock);
                 list_del(&pSMBFile->flist);
                 list_del(&pSMBFile->tlist);
@@ -570,6 +585,21 @@ int cifs_closedir(struct inode *inode, struct file *file)
         return rc;
 }
 
+static int store_file_lock(struct cifsFileInfo *fid, __u64 len,
+                                __u64 offset, __u8 lockType)
+{
+        struct cifsLockInfo *li = kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
+        if (li == NULL)
+                return -ENOMEM;
+        li->offset = offset;
+        li->length = len;
+        li->type = lockType;
+        down(&fid->lock_sem);
+        list_add(&li->llist, &fid->llist);
+        up(&fid->lock_sem);
+        return 0;
+}
+
 int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
 {
         int rc, xid;
@@ -581,6 +611,7 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
         struct cifsTconInfo *pTcon;
         __u16 netfid;
         __u8 lockType = LOCKING_ANDX_LARGE_FILES;
+        int posix_locking;
 
         length = 1 + pfLock->fl_end - pfLock->fl_start;
         rc = -EACCES;
@@ -639,14 +670,14 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
         }
         netfid = ((struct cifsFileInfo *)file->private_data)->netfid;
 
+        posix_locking = (cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
+                        (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(cifs_sb->tcon->fsUnixInfo.Capability));
 
         /* BB add code here to normalize offset and length to
         account for negative length which we can not accept over the
         wire */
         if (IS_GETLK(cmd)) {
-                if((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
-                   (CIFS_UNIX_FCNTL_CAP & 
-                        le64_to_cpu(cifs_sb->tcon->fsUnixInfo.Capability))) {
+                if(posix_locking) {
                         int posix_lock_type;
                         if(lockType & LOCKING_ANDX_SHARED_LOCK)
                                 posix_lock_type = CIFS_RDLCK;
@@ -682,9 +713,15 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
                 FreeXid(xid);
                 return rc;
         }
-        if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
-                (CIFS_UNIX_FCNTL_CAP &
-                         le64_to_cpu(cifs_sb->tcon->fsUnixInfo.Capability))) {
+
+        if (!numLock && !numUnlock) {
+                /* if no lock or unlock then nothing
+                to do since we do not know what it is */
+                FreeXid(xid);
+                return -EOPNOTSUPP;
+        }
+
+        if (posix_locking) {
                 int posix_lock_type;
                 if(lockType & LOCKING_ANDX_SHARED_LOCK)
                         posix_lock_type = CIFS_RDLCK;
@@ -693,18 +730,46 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
                 
                 if(numUnlock == 1)
                         posix_lock_type = CIFS_UNLCK;
-                else if(numLock == 0) {
-                        /* if no lock or unlock then nothing
-                        to do since we do not know what it is */
-                        FreeXid(xid);
-                        return -EOPNOTSUPP;
-                }
+
                 rc = CIFSSMBPosixLock(xid, pTcon, netfid, 0 /* set */,
                                       length, pfLock,
                                       posix_lock_type, wait_flag);
-        } else
-                rc = CIFSSMBLock(xid, pTcon, netfid, length, pfLock->fl_start,
-                                numUnlock, numLock, lockType, wait_flag);
+        } else {
+                struct cifsFileInfo *fid = (struct cifsFileInfo *)file->private_data;
+
+                if (numLock) {
+                        rc = CIFSSMBLock(xid, pTcon, netfid, length, pfLock->fl_start,
+                                        0, numLock, lockType, wait_flag);
+
+                        if (rc == 0) {
+                                /* For Windows locks we must store them. */
+                                rc = store_file_lock(fid, length,
+                                                pfLock->fl_start, lockType);
+                        }
+                } else if (numUnlock) {
+                        /* For each stored lock that this unlock overlaps
+                           completely, unlock it. */
+                        int stored_rc = 0;
+                        struct cifsLockInfo *li, *tmp;
+
+                        down(&fid->lock_sem);
+                        list_for_each_entry_safe(li, tmp, &fid->llist, llist) {
+                                if (pfLock->fl_start <= li->offset &&
+                                                length >= li->length) {
+                                        stored_rc = CIFSSMBLock(xid, pTcon, netfid,
+                                                        li->length, li->offset,
+                                                        1, 0, li->type, FALSE);
+                                        if (stored_rc)
+                                                rc = stored_rc;
+
+                                        list_del(&li->llist);
+                                        kfree(li);
+                                }
+                        }
+                up(&fid->lock_sem);
+                }
+        }
+
         if (pfLock->fl_flags & FL_POSIX)
                 posix_lock_file_wait(file, pfLock);
         FreeXid(xid);