From: Chunhai Guo <guochunhai@xxxxxxxx>
[ Upstream commit 936aa701d82d397c2d1afcd18ce2c739471d978d ]
z_erofs_pcluster_readmore() may take a long time to loop when the page
offset is large enough, which is unnecessary should be prevented.
For example, when the following case is encountered, it will loop 4691368
times, taking about 27 seconds:
- offset = 19217289215
- inode_size = 1442672
Signed-off-by: Chunhai Guo <guochunhai@xxxxxxxx>
Fixes: 386292919c25 ("erofs: introduce readmore decompression strategy")
Reviewed-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Reviewed-by: Yue Hu <huyue2@xxxxxxxxxxx>
Reviewed-by: Chao Yu <chao@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230710042531.28761-1-guochunhai@xxxxxxxx
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/erofs/zdata.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 502893e3da010..bedfff5d45faf 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1807,7 +1807,7 @@ static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f,
}
cur = map->m_la + map->m_llen - 1;
- while (cur >= end) {
+ while ((cur >= end) && (cur < i_size_read(inode))) {
pgoff_t index = cur >> PAGE_SHIFT;
struct page *page;
--
2.39.2
