2023-11-28 17:59:44

by Gao Xiang

Subject: [PATCH] erofs: fix memory leak on short-lived bounced pages

Both MicroLZMA and DEFLATE algorithms can use short-lived pages on
demand for overlap inplace I/O decompression.

However, those short-lived pages are actually added to
`be->decompressed_pages`. Thus, it should be checked instead of
`pcl->compressed_bvecs`.

The LZ4 algorithm doesn't work like this, so it won't be impacted.

Fixes: 67139e36d970 ("erofs: introduce `z_erofs_parse_in_bvecs'")
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/zdata.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index a7e6847f6f8f..e5e44f926692 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1309,12 +1309,11 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
put_page(page);
} else {
for (i = 0; i < pclusterpages; ++i) {
- page = pcl->compressed_bvecs[i].page;
+ /* consider shortlived pages added when decompressing */
+ page = be->decompressed_pages[i];

if (erofs_page_is_managed(sbi, page))
continue;
-
- /* recycle all individual short-lived pages */
(void)z_erofs_put_shortlivedpage(be->pagepool, page);
WRITE_ONCE(pcl->compressed_bvecs[i].page, NULL);
}
--
2.39.3

2023-11-28 18:04:52

by Gao Xiang

Subject: [PATCH v2] erofs: fix memory leak on short-lived bounced pages

Both MicroLZMA and DEFLATE algorithms can use short-lived pages on
demand for overlap inplace I/O decompression.

However, those short-lived pages are actually added to
`be->compressed_pages`. Thus, it should be checked instead of
`pcl->compressed_bvecs`.

The LZ4 algorithm doesn't work like this, so it won't be impacted.

Fixes: 67139e36d970 ("erofs: introduce `z_erofs_parse_in_bvecs'")
Signed-off-by: Gao Xiang <[email protected]>
---
v2:
- should be `be->compressed_pages`.

fs/erofs/zdata.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index a7e6847f6f8f..a33cd6757f98 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1309,12 +1309,11 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
put_page(page);
} else {
for (i = 0; i < pclusterpages; ++i) {
- page = pcl->compressed_bvecs[i].page;
+ /* consider shortlived pages added when decompressing */
+ page = be->compressed_pages[i];

if (erofs_page_is_managed(sbi, page))
continue;
-
- /* recycle all individual short-lived pages */
(void)z_erofs_put_shortlivedpage(be->pagepool, page);
WRITE_ONCE(pcl->compressed_bvecs[i].page, NULL);
}
--
2.39.3

2023-11-29 05:39:36

by Yue Hu

Subject: Re: [PATCH v2] erofs: fix memory leak on short-lived bounced pages

On Wed, 29 Nov 2023 02:04:31 +0800
Gao Xiang <[email protected]> wrote:

> Both MicroLZMA and DEFLATE algorithms can use short-lived pages on
> demand for overlap inplace I/O decompression.
>
> However, those short-lived pages are actually added to
> `be->compressed_pages`. Thus, it should be checked instead of
> `pcl->compressed_bvecs`.
>
> The LZ4 algorithm doesn't work like this, so it won't be impacted.
>
> Fixes: 67139e36d970 ("erofs: introduce `z_erofs_parse_in_bvecs'")
> Signed-off-by: Gao Xiang <[email protected]>

Reviewed-by: Yue Hu <[email protected]>

2023-12-14 15:02:03

by Chao Yu

Subject: Re: [PATCH v2] erofs: fix memory leak on short-lived bounced pages

On 2023/11/29 2:04, Gao Xiang wrote:
> Both MicroLZMA and DEFLATE algorithms can use short-lived pages on
> demand for overlap inplace I/O decompression.
>
> However, those short-lived pages are actually added to
> `be->compressed_pages`. Thus, it should be checked instead of
> `pcl->compressed_bvecs`.
>
> The LZ4 algorithm doesn't work like this, so it won't be impacted.
>
> Fixes: 67139e36d970 ("erofs: introduce `z_erofs_parse_in_bvecs'")
> Signed-off-by: Gao Xiang <[email protected]>

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

Thanks,