Messages in this thread | | | Date | Thu, 12 Jan 2023 22:03:27 -0500 | Subject | Re: [PATCH v5 09/23] cifs: Convert wdata_alloc_and_fillpages() to use filemap_get_folios_tag() | From | Tom Talpey <> |
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This code would be a lot more readable if it had fewer goto's. The goto out's are ok but the again and add_more are easily eliminated.
Two possibilities...
On 1/12/2023 12:19 PM, Vishal Moola wrote: > On Wed, Jan 4, 2023 at 1:15 PM Vishal Moola (Oracle) > <vishal.moola@gmail.com> wrote: >> >> This is in preparation for the removal of find_get_pages_range_tag(). Now also >> supports the use of large folios. >> >> Since tofind might be larger than the max number of folios in a >> folio_batch (15), we loop through filling in wdata->pages pulling more >> batches until we either reach tofind pages or run out of folios. >> >> This function may not return all pages in the last found folio before >> tofind pages are reached. >> >> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> >> --- >> fs/cifs/file.c | 32 +++++++++++++++++++++++++++++--- >> 1 file changed, 29 insertions(+), 3 deletions(-) >> >> diff --git a/fs/cifs/file.c b/fs/cifs/file.c >> index 22dfc1f8b4f1..8cdd2f67af24 100644 >> --- a/fs/cifs/file.c >> +++ b/fs/cifs/file.c >> @@ -2527,14 +2527,40 @@ wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping, >> unsigned int *found_pages) >> { >> struct cifs_writedata *wdata; >> - >> + struct folio_batch fbatch; >> + unsigned int i, idx, p, nr; >> wdata = cifs_writedata_alloc((unsigned int)tofind, >> cifs_writev_complete); >> if (!wdata) >> return NULL; >> >> - *found_pages = find_get_pages_range_tag(mapping, index, end, >> - PAGECACHE_TAG_DIRTY, tofind, wdata->pages); >> + folio_batch_init(&fbatch); >> + *found_pages = 0; >> +
This is really just the top of a while loop:
while (nr = filemap_get_folios_tag(...)) {
>> +again: >> + nr = filemap_get_folios_tag(mapping, index, end, >> + PAGECACHE_TAG_DIRTY, &fbatch); >> + if (!nr) >> + goto out; /* No dirty pages left in the range */ >> + >> + for (i = 0; i < nr; i++) { >> + struct folio *folio = fbatch.folios[i]; >> + >> + idx = 0; >> + p = folio_nr_pages(folio);
And this is a "do {"
>> +add_more: >> + wdata->pages[*found_pages] = folio_page(folio, idx); >> + folio_get(folio); >> + if (++*found_pages == tofind) { >> + folio_batch_release(&fbatch); >> + goto out; >> + } >> + if (++idx < p) >> + goto add_more;
To here "} while (++idx < p);"
>> + } >> + folio_batch_release(&fbatch); >> + goto again;
End while "}"
>> +out: >> return wdata; >> } >> >> -- >> 2.38.1 >> > > Could someone review this cifs patch, please? This is one of the > 2 remaining patches that need to be looked at in the series.
It's otherwise ok.
Tom. >
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