If non-bootstrap bvecs cannot be kept in place (very rarely), an extra
short-lived page is allocated.
Let's just allocate it immediately rather than do unnecessary -EAGAIN
return first and retry as a cleanup. Also it's unnecessary to use
__GFP_NOFAIL here since we could gracefully fail out this case instead.
Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
fs/erofs/zdata.c | 32 ++++++++++++--------------------
1 file changed, 12 insertions(+), 20 deletions(-)
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 45f21db2303a..5f11362d617d 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -243,12 +243,17 @@ static int z_erofs_bvec_enqueue(struct z_erofs_bvec_iter
*iter,
struct z_erofs_bvec *bvec,
struct page **candidate_bvpage)
{
- if (iter->cur == iter->nr) {
- if (!*candidate_bvpage)
- return -EAGAIN;
-
+ if (iter->cur >= iter->nr) {
+ struct page *nextpage = *candidate_bvpage;
+
+ if (!nextpage) {
+ nextpage = alloc_page(GFP_NOFS);
+ if (!nextpage)
+ return -ENOMEM;
+ set_page_private(nextpage, Z_EROFS_SHORTLIVED_PAGE);
+ }
DBG_BUGON(iter->bvset->nextpage);
- iter->bvset->nextpage = *candidate_bvpage;
+ iter->bvset->nextpage = nextpage;
z_erofs_bvset_flip(iter);
iter->bvset->nextpage = NULL;
@@ -910,10 +915,8 @@ static bool z_erofs_collector_end(struct
z_erofs_decompress_frontend *fe)
z_erofs_bvec_iter_end(&fe->biter);
mutex_unlock(&pcl->lock);
- if (fe->candidate_bvpage) {
- DBG_BUGON(z_erofs_is_shortlived_page(fe->candidate_bvpage));
+ if (fe->candidate_bvpage)
fe->candidate_bvpage = NULL;
- }
/*
* if all pending pages are added, don't hold its reference
@@ -1058,24 +1061,13 @@ static int z_erofs_do_read_page(struct
z_erofs_decompress_frontend *fe,
if (cur)
tight &= (fe->mode >= Z_EROFS_PCLUSTER_FOLLOWED);
-retry:
err = z_erofs_attach_page(fe, &((struct z_erofs_bvec) {
.page = page,
.offset = offset - map->m_la,
.end = end,
}), exclusive);
- /* should allocate an additional short-lived page for bvset */
- if (err == -EAGAIN && !fe->candidate_bvpage) {
- fe->candidate_bvpage = alloc_page(GFP_NOFS | __GFP_NOFAIL);
- set_page_private(fe->candidate_bvpage,
- Z_EROFS_SHORTLIVED_PAGE);
- goto retry;
- }
-
- if (err) {
- DBG_BUGON(err == -EAGAIN && fe->candidate_bvpage);
+ if (err)
goto out;
- }
z_erofs_onlinepage_split(page);
/* bump up the number of spiltted parts of a page */
--
2.24.4
