This is needed for swapon(2) files in the union.
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
---
fs/unionfs/mmap.c | 23 +++++++++++++++++++++++
1 files changed, 23 insertions(+), 0 deletions(-)
diff --git a/fs/unionfs/mmap.c b/fs/unionfs/mmap.c
index 3f65e52..fa358ef 100644
--- a/fs/unionfs/mmap.c
+++ b/fs/unionfs/mmap.c
@@ -304,10 +304,33 @@ out:
return err; /* assume all is ok */
}
+/*
+ * Although unionfs isn't a block-based file system, it may stack on one.
+ * ->bmap is needed, for example, to swapon(2) files.
+ */
+sector_t unionfs_bmap(struct address_space *mapping, sector_t block)
+{
+ int err = -EINVAL;
+ struct inode *inode, *lower_inode;
+ sector_t (*bmap)(struct address_space *, sector_t);
+
+ inode = (struct inode *)mapping->host;
+ lower_inode = unionfs_lower_inode(inode);
+ if (!lower_inode)
+ goto out;
+ bmap = lower_inode->i_mapping->a_ops->bmap;
+ if (bmap)
+ err = bmap(lower_inode->i_mapping, block);
+out:
+ return err;
+}
+
+
struct address_space_operations unionfs_aops = {
.writepage = unionfs_writepage,
.writepages = unionfs_writepages,
.readpage = unionfs_readpage,
.prepare_write = unionfs_prepare_write,
.commit_write = unionfs_commit_write,
+ .bmap = unionfs_bmap,
};
--
1.5.2.2
-
