On 2023/11/11 01:09, Matthew Wilcox wrote:
On Thu, Nov 09, 2023 at 10:50:45PM +0100, Andreas Gruenbacher wrote:
On Tue, Nov 7, 2023 at 10:27 PM Matthew Wilcox (Oracle)
<willy@xxxxxxxxxxxxx> wrote:
+static inline void folio_fill_tail(struct folio *folio, size_t offset,
+ const char *from, size_t len)
+{
+ char *to = kmap_local_folio(folio, offset);
+
+ VM_BUG_ON(offset + len > folio_size(folio));
+
+ if (folio_test_highmem(folio)) {
+ size_t max = PAGE_SIZE - offset_in_page(offset);
+
+ while (len > max) {
+ memcpy(to, from, max);
+ kunmap_local(to);
+ len -= max;
+ from += max;
+ offset += max;
+ max = PAGE_SIZE;
+ to = kmap_local_folio(folio, offset);
+ }
+ }
+
+ memcpy(to, from, len);
+ to = folio_zero_tail(folio, offset, to);
This needs to be:
to = folio_zero_tail(folio, offset + len, to + len);
Oh, wow, that was stupid of me. I only ran an xfstests against ext4,
which doesn't exercise this code, not gfs2 or erofs. Thanks for
fixing this up.
Assuming that is for the next cycle (no rush), I will also test
this patch and feedback later since I'm now working on other
stuffs.
Thanks,
Gao Xiang
