leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

shmem: convert shmem_fallocate() to use a folio

Browse Source 
Call shmem_get_folio() and use the folio APIs instead of the page APIs. 
Saves several calls to compound_head() and removes assumptions about the
size of a large folio.

Link: https://lkml.kernel.org/r/20220902194653.1739778-29-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2022-09-02 20:46:24 +01:00 committed by Andrew Morton
parent 4601e2fc8b
commit b0802b22a9
1 changed files with 17 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
mm/shmem.c
View File

@ -2787,7 +2787,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
info->fallocend = end;
for (index = start; index < end; ) {
struct page *page;
struct folio *folio;
/*
* Good, the fallocate(2) manpage permits EINTR: we may have
@ -2798,10 +2798,11 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
else if (shmem_falloc.nr_unswapped > shmem_falloc.nr_falloced)
error = -ENOMEM;
else
error = shmem_getpage(inode, index, &page, SGP_FALLOC);
error = shmem_get_folio(inode, index, &folio,
SGP_FALLOC);
if (error) {
info->fallocend = undo_fallocend;
/* Remove the !PageUptodate pages we added */
/* Remove the !uptodate folios we added */
if (index > start) {
shmem_undo_range(inode,
(loff_t)start << PAGE_SHIFT,
@ -2810,37 +2811,34 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
goto undone;
}
index++;
/*
* Here is a more important optimization than it appears:
* a second SGP_FALLOC on the same huge page will clear it,
* making it PageUptodate and un-undoable if we fail later.
* a second SGP_FALLOC on the same large folio will clear it,
* making it uptodate and un-undoable if we fail later.
*/
if (PageTransCompound(page)) {
index = round_up(index, HPAGE_PMD_NR);
/* Beware 32-bit wraparound */
if (!index)
index--;
}
index = folio_next_index(folio);
/* Beware 32-bit wraparound */
if (!index)
index--;
/*
* Inform shmem_writepage() how far we have reached.
* No need for lock or barrier: we have the page lock.
*/
if (!PageUptodate(page))
if (!folio_test_uptodate(folio))
shmem_falloc.nr_falloced += index - shmem_falloc.next;
shmem_falloc.next = index;
/*
* If !PageUptodate, leave it that way so that freeable pages
* If !uptodate, leave it that way so that freeable folios
* can be recognized if we need to rollback on error later.
* But set_page_dirty so that memory pressure will swap rather
* than free the pages we are allocating (and SGP_CACHE pages
* But mark it dirty so that memory pressure will swap rather
* than free the folios we are allocating (and SGP_CACHE folios
* might still be clean: we now need to mark those dirty too).
*/
set_page_dirty(page);
unlock_page(page);
put_page(page);
folio_mark_dirty(folio);
folio_unlock(folio);
folio_put(folio);
cond_resched();
}