2.4.22-rc1 FIFO bug still present

From: Rob van Nieuwkerk (robn@verdi.et.tudelft.nl)
Date: Wed Aug 06 2003 - 12:23:06 EST


Hi Marcelo,

FYI:
I see that the "FIFO inode time-stamps are updated on a *readonly* fs"
bug is still not fixed in 2.4.22-rc1.

(this bug is a efficient way to destroy your CompactFlash devices in
certain applications ..)

Stephen C. Tweedie made a fix (see below) for it in May.
It has been in the Alan's -ac series since then and it works fine.

for more info see:

        http://www.ussg.iu.edu/hypermail/linux/kernel/0305.3/1132.html
        http://www.ussg.iu.edu/hypermail/linux/kernel/0305.3/1604.html

        greetings,
        Rob van Nieuwkerk

The patch:
(http://www.ussg.iu.edu/hypermail/linux/kernel/0305.3/att-1604/01-4202-vfs-mctime-rofs.patch):
###################################################################

--- 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);

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This archive was generated by hypermail 2b29 : Thu Aug 07 2003 - 22:00:34 EST