2024-03-05 09:15:08

by Gao Xiang

Subject: [PATCH 3/6] erofs: get rid of `justfound` debugging tag

`justfound` is introduced to identify cached folios that are just added
to compressed bvecs so that more checks can be applied in the I/O
submission path.

EROFS is quite now stable compared to the codebase at that stage.
`justfound` becomes a burden for upcoming features. Drop it.

Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/zdata.c | 20 +++-----------------
1 file changed, 3 insertions(+), 17 deletions(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index c25074657708..75b05990b571 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -565,17 +565,13 @@ static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe)

for (i = 0; i < pclusterpages; ++i) {
struct page *page, *newpage;
- void *t; /* mark pages just found for debugging */

/* Inaccurate check w/o locking to avoid unneeded lookups */
if (READ_ONCE(pcl->compressed_bvecs[i].page))
continue;

page = find_get_page(mc, pcl->obj.index + i);
- if (page) {
- t = (void *)((unsigned long)page | 1);
- newpage = NULL;
- } else {
+ if (!page) {
/* I/O is needed, no possible to decompress directly */
standalone = false;
if (!shouldalloc)
@@ -589,11 +585,10 @@ static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe)
if (!newpage)
continue;
set_page_private(newpage, Z_EROFS_PREALLOCATED_PAGE);
- t = (void *)((unsigned long)newpage | 1);
}
spin_lock(&pcl->obj.lockref.lock);
if (!pcl->compressed_bvecs[i].page) {
- pcl->compressed_bvecs[i].page = t;
+ pcl->compressed_bvecs[i].page = page ? page : newpage;
spin_unlock(&pcl->obj.lockref.lock);
continue;
}
@@ -1423,7 +1418,7 @@ static void z_erofs_fill_bio_vec(struct bio_vec *bvec,
struct z_erofs_bvec zbv;
struct address_space *mapping;
struct page *page;
- int justfound, bs = i_blocksize(f->inode);
+ int bs = i_blocksize(f->inode);

/* Except for inplace pages, the entire page can be used for I/Os */
bvec->bv_offset = 0;
@@ -1432,9 +1427,6 @@ static void z_erofs_fill_bio_vec(struct bio_vec *bvec,
spin_lock(&pcl->obj.lockref.lock);
zbv = pcl->compressed_bvecs[nr];
page = zbv.page;
- justfound = (unsigned long)page & 1UL;
- page = (struct page *)((unsigned long)page & ~1UL);
- pcl->compressed_bvecs[nr].page = page;
spin_unlock(&pcl->obj.lockref.lock);
if (!page)
goto out_allocpage;
@@ -1465,9 +1457,6 @@ static void z_erofs_fill_bio_vec(struct bio_vec *bvec,
}

lock_page(page);
- /* only true if page reclaim goes wrong, should never happen */
- DBG_BUGON(justfound && PagePrivate(page));
-
/* the cached page is still in managed cache */
if (page->mapping == mc) {
/*
@@ -1475,7 +1464,6 @@ static void z_erofs_fill_bio_vec(struct bio_vec *bvec,
* `->private` pcluster hint. Let's reconnect them.
*/
if (!PagePrivate(page)) {
- DBG_BUGON(!justfound);
/* compressed_bvecs[] already takes a ref */
attach_page_private(page, pcl);
put_page(page);
@@ -1494,8 +1482,6 @@ static void z_erofs_fill_bio_vec(struct bio_vec *bvec,
* allocate a new page for compressed data.
*/
DBG_BUGON(page->mapping);
- DBG_BUGON(!justfound);
-
tocache = true;
unlock_page(page);
put_page(page);
--
2.39.3

2024-03-10 01:05:55

by Chao Yu

Subject: Re: [PATCH 3/6] erofs: get rid of `justfound` debugging tag

On 2024/3/5 17:14, Gao Xiang wrote:
> `justfound` is introduced to identify cached folios that are just added
> to compressed bvecs so that more checks can be applied in the I/O
> submission path.
>
> EROFS is quite now stable compared to the codebase at that stage.
> `justfound` becomes a burden for upcoming features. Drop it.
>
> Signed-off-by: Gao Xiang <[email protected]>

Reviewed-by: Chao Yu <[email protected]>

Thanks,