Re: [V3 PATCH 1/2] tmpfs: add fallocate support

From: Cong Wang
Date: Wed Nov 23 2011 - 22:18:40 EST


ä 2011å11æ24æ 03:07, Hugh Dickins åé:
On Wed, 23 Nov 2011, Cong Wang wrote:
+
+ while (index< end) {
+ ret = shmem_getpage(inode, index,&page, SGP_WRITE, NULL);
+ if (ret) {
+ if (ret == -ENOSPC)
+ goto undo;
...
+undo:
+ while (index> start) {
+ shmem_truncate_page(inode, index);
+ index--;
+ }

As I said before, I won't actually be reviewing and testing this for
a week or two; but before this goes any further, must point out how
wrong it is. Here you'll be deleting any pages in the range that were
already present before the failing fallocate().

Ah, I totally missed this. So, is there any way to tell if the page
gotten from shmem_getpage() is newly allocated or not?

I will dig the code...

Thanks.
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