default to simple_setattr

With the new truncate sequence every filesystem that wants to support file
size changes on disk needs to implement its own ->setattr.  So instead
of calling inode_setattr which supports size changes call into a simple
method that doesn't support this.  simple_setattr is almost what we
want except that it does not mark the inode dirty after changes.  Given
that marking the inode dirty is a no-op for the simple in-memory filesystems
that use simple_setattr currently just add the mark_inode_dirty call.

Also add a WARN_ON for the presence of a truncate method to simple_setattr
to catch new instances of it during the transition period.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/attr.c b/fs/attr.c
index 1f6a895e24e9f641cb41343918e67bd794fadff6..aeac826f4774c185b5e60e0c1d1b4e516755b2ff 100644 (file)
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -237,13 +237,10 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
        if (ia_valid & ATTR_SIZE)
                down_write(&dentry->d_inode->i_alloc_sem);
 
-       if (inode->i_op && inode->i_op->setattr) {
+       if (inode->i_op->setattr)
                error = inode->i_op->setattr(dentry, attr);
-       } else {
-               error = inode_change_ok(inode, attr);
-               if (!error)
-                       error = inode_setattr(inode, attr);
-       }
+       else
+               error = simple_setattr(dentry, attr);
 
        if (ia_valid & ATTR_SIZE)
                up_write(&dentry->d_inode->i_alloc_sem);

diff --git a/fs/libfs.c b/fs/libfs.c
index 861a88797716071efa859b2de01a2b798a1ab3bb..40562224b71899c12377eb6b572f2bcac672f57c 100644 (file)
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -370,21 +370,26 @@ int simple_setsize(struct inode *inode, loff_t newsize)
 EXPORT_SYMBOL(simple_setsize);
 
 /**
- * simple_setattr - setattr for simple in-memory filesystem
+ * simple_setattr - setattr for simple filesystem
  * @dentry: dentry
  * @iattr: iattr structure
  *
  * Returns 0 on success, -error on failure.
  *
- * simple_setattr implements setattr for an in-memory filesystem which
- * does not store its own file data or metadata (eg. uses the page cache
- * and inode cache as its data store).
+ * simple_setattr is a simple ->setattr implementation without a proper
+ * implementation of size changes.
+ *
+ * It can either be used for in-memory filesystems or special files
+ * on simple regular filesystems.  Anything that needs to change on-disk
+ * or wire state on size changes needs its own setattr method.
  */
 int simple_setattr(struct dentry *dentry, struct iattr *iattr)
 {
        struct inode *inode = dentry->d_inode;
        int error;
 
+       WARN_ON_ONCE(inode->i_op->truncate);
+
        error = inode_change_ok(inode, iattr);
        if (error)
                return error;
@@ -396,7 +401,8 @@ int simple_setattr(struct dentry *dentry, struct iattr *iattr)
        }
 
        setattr_copy(inode, iattr);
-       return error;
+       mark_inode_dirty(inode);
+       return 0;
 }
 EXPORT_SYMBOL(simple_setattr);