CIFS: Implement cifs_relock_file

that reacquires byte-range locks when a file is reopened.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
This commit is contained in:
Pavel Shilovsky 2012-11-22 17:10:57 +04:00 committed by Steve French
parent b8db928b76
commit f152fd5fff

View File

@ -505,16 +505,36 @@ out:
return rc;
}
static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
/*
* Try to reacquire byte range locks that were released when session
* to server was lost
* to server was lost.
*/
static int cifs_relock_file(struct cifsFileInfo *cifsFile)
static int
cifs_relock_file(struct cifsFileInfo *cfile)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
int rc = 0;
/* BB list all locks open on this file and relock */
/* we are going to update can_cache_brlcks here - need a write access */
down_write(&cinode->lock_sem);
if (cinode->can_cache_brlcks) {
/* can cache locks - no need to push them */
up_write(&cinode->lock_sem);
return rc;
}
if (cap_unix(tcon->ses) &&
(CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
rc = cifs_push_posix_locks(cfile);
else
rc = tcon->ses->server->ops->push_mand_locks(cfile);
up_write(&cinode->lock_sem);
return rc;
}