From 00e45efaf9ff8fdf9f66c69307f9dd133f33809f Mon Sep 17 00:00:00 2001 From: Zhe Li Date: Fri, 29 May 2020 11:37:11 +0800 Subject: [PATCH] jffs2: Fix GC exit abnormally commit 9afc9a8a4909fece0e911e72b1060614ba2f7969 upstream. The log of this problem is: jffs2: Error garbage collecting node at 0x***! jffs2: No space for garbage collection. Aborting GC thread This is because GC believe that it do nothing, so it abort. After going over the image of jffs2, I find a scene that can trigger this problem stably. The scene is: there is a normal dirent node at summary-area, but abnormal at corresponding not-summary-area with error name_crc. The reason that GC exit abnormally is because it find that abnormal dirent node to GC, but when it goes to function jffs2_add_fd_to_list, it cannot meet the condition listed below: if ((*prev)->nhash == new->nhash && !strcmp((*prev)->name, new->name)) So no node is marked obsolete, statistical information of erase_block do not change, which cause GC exit abnormally. The root cause of this problem is: we do not check the name_crc of the abnormal dirent node with summary is enabled. Noticed that in function jffs2_scan_dirent_node, we use function jffs2_scan_dirty_space to deal with the dirent node with error name_crc. So this patch add a checking code in function read_direntry to ensure the correctness of dirent node. If checked failed, the dirent node will be marked obsolete so GC will pass this node and this problem will be fixed. Cc: Signed-off-by: Zhe Li Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman --- fs/jffs2/readinode.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c index bccfc40b3a74..d19483fa1fe8 100644 --- a/fs/jffs2/readinode.c +++ b/fs/jffs2/readinode.c @@ -672,6 +672,22 @@ static inline int read_direntry(struct jffs2_sb_info *c, struct jffs2_raw_node_r jffs2_free_full_dirent(fd); return -EIO; } + +#ifdef CONFIG_JFFS2_SUMMARY + /* + * we use CONFIG_JFFS2_SUMMARY because without it, we + * have checked it while mounting + */ + crc = crc32(0, fd->name, rd->nsize); + if (unlikely(crc != je32_to_cpu(rd->name_crc))) { + JFFS2_NOTICE("name CRC failed on dirent node at" + "%#08x: read %#08x,calculated %#08x\n", + ref_offset(ref), je32_to_cpu(rd->node_crc), crc); + jffs2_mark_node_obsolete(c, ref); + jffs2_free_full_dirent(fd); + return 0; + } +#endif } fd->nhash = full_name_hash(NULL, fd->name, rd->nsize);