erofs: fix memory leak on short-lived bounced pages

[ Upstream commit 93d6fda7f926451a0fa1121b9558d75ca47e861e ]

Both MicroLZMA and DEFLATE algorithms can use short-lived pages on
demand for the overlapped 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'")
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20231128180431.4116991-1-hsiangkao@linux.alibaba.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index a7e6847..a33cd67 100644 (file)
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1309,12 +1309,11 @@ out:
                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);
                }