Re: ramfs and directory modification time

Re: ramfs and directory modification time

[Chuck Ebbert]

In-Reply-To: <20060224040400.2f093523.akpm@osdl.org>

On Fri, 24 Feb 2006 at 04:04:00 -0800, Andrew Morton wrote:

> --- devel/fs/ramfs/inode.c~ramfs-update-dir-mtime-and-ctime   2006-02-24 03:53:46.000000000 -0800
> +++ devel-akpm/fs/ramfs/inode.c       2006-02-24 03:54:29.000000000 -0800
> @@ -27,6 +27,7 @@
>  #include <linux/fs.h>
>  #include <linux/pagemap.h>
>  #include <linux/highmem.h>
> +#include <linux/time.h>
>  #include <linux/init.h>
>  #include <linux/string.h>
>  #include <linux/smp_lock.h>
> @@ -104,6 +105,7 @@ ramfs_mknod(struct inode *dir, struct de
>               d_instantiate(dentry, inode);
>               dget(dentry);   /* Extra count - pin the dentry in core */
>               error = 0;
> +             dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
>       }
>       return error;
>  }


 Shouldn't that be CURRENT_TIME?

[me@tu ramfs]$ grep -i current_time *
inode.c:                inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;


-- 
Chuck
"Equations are the Devil's sentences."  --Stephen Colbert

Re: ramfs and directory modification time

[Andrew Morton]

"Ph. Marek" <philipp.marek@bmlv.gv.at> wrote:
>
> I believe that I found a problem regarding ramfs and directory modification 
>  times.
> 
> 
> 
>  Observe:
>  	$ /tmp# mkdir newdir
>  	$ /tmp# mount -t ramfs none newdir
>  	$ /tmp# cd newdir/
>  	$ /tmp/newdir# mkdir sub
>  	$ /tmp/newdir# cd sub
>  	$ /tmp/newdir/sub# ls -la --full-time
>  	total 0
>  	drwxr-xr-x 2 root root 0 2006-02-23 14:01:37.573655160 +0100 .
>  	drwxr-xr-x 3 root root 0 2006-02-23 14:01:33.221316816 +0100 ..
>  	$ /tmp/newdir/sub# touch a-new-file
>  	$ /tmp/newdir/sub# ls -la --full-time
>  	total 0
>  	drwxr-xr-x 2 root root 0 2006-02-23 14:01:37.573655160 +0100 .
>  	drwxr-xr-x 3 root root 0 2006-02-23 14:01:33.221316816 +0100 ..
>  	-rw-r--r-- 1 root root 0 2006-02-23 14:01:48.019067216 +0100 a-new-file
> 
>  On a tmpfs or other (disk-based) filesystems (ext3) it works correctly.

Yes, bug.  Thanks.


--- devel/fs/ramfs/inode.c~ramfs-update-dir-mtime-and-ctime	2006-02-24 03:53:46.000000000 -0800
+++ devel-akpm/fs/ramfs/inode.c	2006-02-24 03:54:29.000000000 -0800
@@ -27,6 +27,7 @@
 #include <linux/fs.h>
 #include <linux/pagemap.h>
 #include <linux/highmem.h>
+#include <linux/time.h>
 #include <linux/init.h>
 #include <linux/string.h>
 #include <linux/smp_lock.h>
@@ -104,6 +105,7 @@ ramfs_mknod(struct inode *dir, struct de
 		d_instantiate(dentry, inode);
 		dget(dentry);	/* Extra count - pin the dentry in core */
 		error = 0;
+		dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
 	}
 	return error;
 }
_

ramfs and directory modification time

[Ph. Marek]

Hello everybody,

I believe that I found a problem regarding ramfs and directory modification 
times.



Observe:
	$ /tmp# mkdir newdir
	$ /tmp# mount -t ramfs none newdir
	$ /tmp# cd newdir/
	$ /tmp/newdir# mkdir sub
	$ /tmp/newdir# cd sub
	$ /tmp/newdir/sub# ls -la --full-time
	total 0
	drwxr-xr-x 2 root root 0 2006-02-23 14:01:37.573655160 +0100 .
	drwxr-xr-x 3 root root 0 2006-02-23 14:01:33.221316816 +0100 ..
	$ /tmp/newdir/sub# touch a-new-file
	$ /tmp/newdir/sub# ls -la --full-time
	total 0
	drwxr-xr-x 2 root root 0 2006-02-23 14:01:37.573655160 +0100 .
	drwxr-xr-x 3 root root 0 2006-02-23 14:01:33.221316816 +0100 ..
	-rw-r--r-- 1 root root 0 2006-02-23 14:01:48.019067216 +0100 a-new-file

On a tmpfs or other (disk-based) filesystems (ext3) it works correctly.
Is that a design wish, that ramfs is kept as simple as possible?

Nevertheless I believe that should be fixed, as everything that relies on the 
directory mtime won't work on an ramfs.


This is 2.6.26-rc4, btw, on x86.


Please CC me as I'm not subscribed (although I surely will have a look in the 
archives, too).


Regards,

Phil