From d23cd508d37c0fed10ff47b96b390e8711e5d0ce Mon Sep 17 00:00:00 2001
From: Stefan Metzmacher <metze@samba.org>
Date: Mon, 15 Dec 2008 10:53:10 +0100
Subject: [PATCH] HOSTFS: Pass fcntl locks down to the hostfs


Signed-off-by: Stefan Metzmacher <metze@samba.org>
---
 fs/hostfs/hostfs.h      |    7 +++++++
 fs/hostfs/hostfs_kern.c |   36 ++++++++++++++++++++++++++++++++++++
 fs/hostfs/hostfs_user.c |   45 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 0 deletions(-)

diff --git a/fs/hostfs/hostfs.h b/fs/hostfs/hostfs.h
index 2f34f8f..3f6fd35 100644
--- a/fs/hostfs/hostfs.h
+++ b/fs/hostfs/hostfs.h
@@ -88,5 +88,12 @@ extern int do_statfs(char *root, long *bsize_out, long long *blocks_out,
 		     long long *files_out, long long *ffree_out,
 		     void *fsid_out, int fsid_size, long *namelen_out,
 		     long *spare_out);
+extern int getlk_file(int fd, unsigned char *type,
+		      unsigned long long *start,
+		      unsigned long long *end,
+		      unsigned int *pid);
+extern int setlk_file(int fd, unsigned char type,
+		      unsigned long long start,
+		      unsigned long long end);
 
 #endif
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 3a31451..8e61611 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -415,6 +415,41 @@ int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync)
 	return fsync_file(HOSTFS_I(dentry->d_inode)->fd, datasync);
 }
 
+int hostfs_lock(struct file *filp, int cmd, struct file_lock *fl)
+{
+	struct inode *inode = filp->f_mapping->host;
+	int ret = -ENOLCK;
+
+	printk("HOSTFS: lock(%s/%s, t=%x, fl=%x, r=%lld:%lld)\n",
+			filp->f_path.dentry->d_parent->d_name.name,
+			filp->f_path.dentry->d_name.name,
+			fl->fl_type, fl->fl_flags,
+			(long long)fl->fl_start, (long long)fl->fl_end);
+
+	if (IS_GETLK(cmd)) {
+		unsigned char type;
+		unsigned long long start;
+		unsigned long long end;
+		unsigned int pid;
+		ret = getlk_file(HOSTFS_I(inode)->fd,
+				 &type, &start, &end, &pid);
+		fl->fl_type = type;
+		if (type != F_UNLCK) {
+			fl->fl_flags = 0;/*???*/
+			fl->fl_start = start;
+			fl->fl_end = end;
+			fl->fl_pid = pid;
+		}
+	} else {
+		ret = setlk_file(HOSTFS_I(inode)->fd,
+				 fl->fl_type,
+				 fl->fl_start,
+				 fl->fl_end);
+	}
+
+	return ret;
+}
+
 static const struct file_operations hostfs_file_fops = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
@@ -426,6 +461,7 @@ static const struct file_operations hostfs_file_fops = {
 	.open		= hostfs_file_open,
 	.release	= NULL,
 	.fsync		= hostfs_fsync,
+	.lock		= hostfs_lock,
 };
 
 static const struct file_operations hostfs_dir_fops = {
diff --git a/fs/hostfs/hostfs_user.c b/fs/hostfs/hostfs_user.c
index b79424f..da5122b 100644
--- a/fs/hostfs/hostfs_user.c
+++ b/fs/hostfs/hostfs_user.c
@@ -429,3 +429,48 @@ int do_statfs(char *root, long *bsize_out, long long *blocks_out,
 	spare_out[4] = buf.f_spare[4];
 	return 0;
 }
+
+int getlk_file(int fd, unsigned char *type,
+	       unsigned long long *start,
+	       unsigned long long *end,
+	       unsigned int *pid)
+{
+	struct flock lock;
+	int err;
+
+	err = fcntl(fd, F_GETLK64, &lock);
+	if (err < 0) {
+		return -errno;
+	}
+
+	*type = lock.l_type;
+	if (lock.l_type != F_UNLCK) {
+		*start = lock.l_start;
+		*end = lock.l_start + lock.l_len;
+		*pid = lock.l_pid;
+	}
+
+	return 0;
+}
+
+int setlk_file(int fd, unsigned char type,
+	       unsigned long long start,
+	       unsigned long long end)
+{
+	struct flock lock;
+	int err;
+
+	lock.l_type = type;
+	lock.l_whence = SEEK_SET;
+	lock.l_start = start;
+	lock.l_len = end - start;
+	lock.l_pid = 0;
+
+	err = fcntl(fd, F_SETLK64, &lock);
+	if (err < 0) {
+		return -errno;
+	}
+
+	return 0;
+}
+
-- 
1.5.4.3