Re: [RFC][PATCH] inotify 0.10.0

[Mike Waychison <Michael.Waychison@Sun.COM>]

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John McCutchan wrote:
|
| --Why Not dnotify and Why inotify (By Robert Love)--
|

| * inotify has an event that says "the filesystem that the item you were
|   watching is on was unmounted" (this is particularly cool).

| +++ linux/fs/super.c	2004-09-18 02:24:33.000000000 -0400
| @@ -36,6 +36,7 @@
|  #include <linux/writeback.h>		/* for the emergency remount stuff */
|  #include <linux/idr.h>
|  #include <asm/uaccess.h>
| +#include <linux/inotify.h>
|
|
|  void get_filesystem(struct file_system_type *fs);
| @@ -204,6 +205,7 @@
|
|  	if (root) {
|  		sb->s_root = NULL;
| +		inotify_super_block_umount (sb);
|  		shrink_dcache_parent(root);
|  		shrink_dcache_anon(&sb->s_anon);
|  		dput(root);

This doesn't seem right.  generic_shutdown_super is only called when the
last instance of a super is released.  If a system were to have a
filesystem mounted in two locations (for instance, by creating a new
namespace), then the umount and ignore would not get propagated when one
is unmounted.

How about an approach that somehow referenced vfsmounts (without having
a reference count proper)?  That way you could queue messages in
umount_tree and do_umount..

- --
Mike Waychison
Sun Microsystems, Inc.
1 (650) 352-5299 voice
1 (416) 202-8336 voice

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