Re: 2.4 bug: fifo-write causes diskwrites to read-only fs !

[Stephen C. Tweedie (sct@redhat.com)]

Hi,

On Fri, 2003-05-30 at 15:58, Christoph Hellwig wrote:

> Yikes, this looks like devfs code!  Please try to use proper kernel style..

It's pure cut-and-paste from the update_atime immediately above it.  But
sure, we can clean them both up while we're at it if you want.

--Stephen

--- linux-2.4-odirect/fs/inode.c.=K0001=.orig
+++ linux-2.4-odirect/fs/inode.c
@@ -1187,12 +1187,34 @@ void update_atime (struct inode *inode)
 {
 	if (inode->i_atime == CURRENT_TIME)
 		return;
-	if ( IS_NOATIME (inode) ) return;
-	if ( IS_NODIRATIME (inode) && S_ISDIR (inode->i_mode) ) return;
-	if ( IS_RDONLY (inode) ) return;
+	if (IS_NOATIME(inode))
+		return;
+	if (IS_NODIRATIME(inode) && S_ISDIR(inode->i_mode)) 
+		return;
+	if (IS_RDONLY(inode)) 
+		return;
 	inode->i_atime = CURRENT_TIME;
 	mark_inode_dirty_sync (inode);
-}   /*  End Function update_atime  */
+}
+
+/**
+ *	update_mctime	-	update the mtime and ctime
+ *	@inode: inode accessed
+ *
+ *	Update the modified and changed times on an inode for writes to special
+ *	files such as fifos.  No change is forced if the timestamps are already
+ *	up-to-date or if the filesystem is readonly.
+ */
+ 
+void update_mctime (struct inode *inode)
+{
+	if (inode->i_mtime == CURRENT_TIME && inode->i_ctime == CURRENT_TIME)
+		return;
+	if (IS_RDONLY(inode))
+		return;
+	inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+	mark_inode_dirty (inode);
+}
 
 
 /*
--- linux-2.4-odirect/fs/pipe.c.=K0001=.orig
+++ linux-2.4-odirect/fs/pipe.c
@@ -230,8 +230,7 @@ pipe_write(struct file *filp, const char
 	/* Signal readers asynchronously that there is more data.  */
 	wake_up_interruptible(PIPE_WAIT(*inode));
 
-	inode->i_ctime = inode->i_mtime = CURRENT_TIME;
-	mark_inode_dirty(inode);
+	update_mctime(inode);
 
 out:
 	up(PIPE_SEM(*inode));
--- linux-2.4-odirect/include/linux/fs.h.=K0001=.orig
+++ linux-2.4-odirect/include/linux/fs.h
@@ -201,6 +201,7 @@ extern int leases_enable, dir_notify_ena
 #include <asm/byteorder.h>
 
 extern void update_atime (struct inode *);
+extern void update_mctime (struct inode *);
 #define UPDATE_ATIME(inode) update_atime (inode)
 
 extern void buffer_init(unsigned long);