From: Chunhai Guo guochunhai@vivo.com
[ 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@vivo.com Fixes: 386292919c25 ("erofs: introduce readmore decompression strategy") Reviewed-by: Gao Xiang hsiangkao@linux.alibaba.com Reviewed-by: Yue Hu huyue2@coolpad.com Reviewed-by: Chao Yu chao@kernel.org Link: https://lore.kernel.org/r/20230710042531.28761-1-guochunhai@vivo.com Signed-off-by: Gao Xiang hsiangkao@linux.alibaba.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 92b2e4ddb7ce9..bf6a369f9c696 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -1660,7 +1660,7 @@ 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;