UPSTREAM: erofs: allocate extra bvec pages directly instead of retrying

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 <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Link: https://lore.kernel.org/r/20230526201459.128169-2-hsiangkao@linux.alibaba.com

Bug: 318378021
(cherry picked from commit 05b63d2beb8b0f752d1f5cdd051c8bdbf532cedd)
Change-Id: I2ac45a943060406bcbb741c5f7aa1094f783f906
Signed-off-by: Sandeep Dhavale <dhavale@google.com>
This commit is contained in:
Gao Xiang 2023-05-27 04:14:54 +08:00 committed by Treehugger Robot
parent bed20ed1d3
commit 5c1827383a

View file

@ -240,12 +240,17 @@ 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;
@ -872,10 +877,8 @@ 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
@ -1023,24 +1026,13 @@ hitted:
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 */