> Index: linux-2.6/mm/memory.c
> ===================================================================
> --- linux-2.6.orig/mm/memory.c
> +++ linux-2.6/mm/memory.c
> @@ -1944,6 +1944,7 @@ static int do_wp_page(struct mm_struct *
> * read-only shared pages can get COWed by
> * get_user_pages(.write=1, .force=1).
> */
> + vfs_check_frozen(old_page->mapping->host->i_sb, SB_FREEZE_WRITE);
> if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
> struct vm_fault vmf;
> int tmp;
it seems strage.
1. it seems to have a race
CPU0 CPU1
----------------------------------------------------
do_wp_page
vfs_check_frozen
ioctl_fsfreeze
freeze_bdev
__fsync_super
process touch mem
vfs_check_frozen only wait to unfreeze, but not prevent new
new freeze request starting.
2. this logic kill multi thread application.
this logic mean mmap_sem grabbing until unfreeze.
it mean othrer thread in the same process can't page-fault although
it don't touch frozen-sb.
it seems strange.
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
