ocfs2: POSIX file locks support
This is actually pretty easy since fs/dlm already handles the bulk of the
work. The Ocfs2 userspace cluster stack module already uses fs/dlm as the
underlying lock manager, so I only had to add the right calls.
Cluster-aware POSIX locks ("plocks") can be turned off by the same means at
UNIX locks - mount with 'noflocks', or create a local-only Ocfs2 volume.
Internally, the file system uses two sets of file_operations, depending on
whether cluster aware plocks is required. This turns out to be easier than
implementing local-only versions of ->lock.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 7e9e4c7..99f012a 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -219,6 +219,7 @@
struct super_block *sb;
struct ocfs2_super *osb;
int status = -EINVAL;
+ int use_plocks = 1;
mlog_entry("(0x%p, size:%llu)\n", inode,
(unsigned long long)le64_to_cpu(fe->i_size));
@@ -226,6 +227,10 @@
sb = inode->i_sb;
osb = OCFS2_SB(sb);
+ if ((osb->s_mount_opt & OCFS2_MOUNT_LOCALFLOCKS) ||
+ ocfs2_mount_local(osb) || !ocfs2_stack_supports_plocks())
+ use_plocks = 0;
+
/* this means that read_inode cannot create a superblock inode
* today. change if needed. */
if (!OCFS2_IS_VALID_DINODE(fe) ||
@@ -295,13 +300,19 @@
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
- inode->i_fop = &ocfs2_fops;
+ if (use_plocks)
+ inode->i_fop = &ocfs2_fops;
+ else
+ inode->i_fop = &ocfs2_fops_no_plocks;
inode->i_op = &ocfs2_file_iops;
i_size_write(inode, le64_to_cpu(fe->i_size));
break;
case S_IFDIR:
inode->i_op = &ocfs2_dir_iops;
- inode->i_fop = &ocfs2_dops;
+ if (use_plocks)
+ inode->i_fop = &ocfs2_dops;
+ else
+ inode->i_fop = &ocfs2_dops_no_plocks;
i_size_write(inode, le64_to_cpu(fe->i_size));
break;
case S_IFLNK: