| Message ID | 20170502062619.497-1-suy.fnst@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 02, 2017 at 02:26:19PM +0800, Su Yue wrote: > The repair_inode_backrefs use the backref again after free while iterating over backrefs. > So let it continue to next step after free can fix it. Please enhance the changelog. I'm missing some explanation that the new code is still correct. I can find that out from code after a while but I need to compare my findings with yours. It's for documentation and also to make sure we both agree on the proposed way to fix it. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/cmds-check.c b/cmds-check.c index 5cc84690..c910e520 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -2666,6 +2666,7 @@ static int repair_inode_backrefs(struct btrfs_root *root, repaired++; list_del(&backref->list); free(backref); + continue; } if (!delete && !backref->found_dir_index && @@ -2676,12 +2677,12 @@ static int repair_inode_backrefs(struct btrfs_root *root, break; repaired++; if (backref->found_dir_item && - backref->found_dir_index && backref->found_dir_index) { if (!backref->errors && backref->found_inode_ref) { list_del(&backref->list); free(backref); + continue; } } }
fsck/004-no-dir-index makes valgrinds complaining about Invalid read. ==31890== Invalid read of size 1 ==31890== at 0x453D09: repair_inode_backrefs (cmds-check.c:2690) ==31890== by 0x453D09: check_inode_recs (cmds-check.c:3330) ==31890== by 0x453D09: check_fs_root (cmds-check.c:4012) ==31890== by 0x45E788: check_fs_roots (cmds-check.c:4098) ==31890== by 0x45E788: cmd_check (cmds-check.c:13031) ==31890== by 0x40A88A: main (btrfs.c:246) ==31890== Address 0x5cb7b90 is 16 bytes inside a block of size 50 free'd ==31890== at 0x4C2C14B: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==31890== by 0x453D08: repair_inode_backrefs (cmds-check.c:2684) ==31890== by 0x453D08: check_inode_recs (cmds-check.c:3330) ==31890== by 0x453D08: check_fs_root (cmds-check.c:4012) ==31890== by 0x45E788: check_fs_roots (cmds-check.c:4098) ==31890== by 0x45E788: cmd_check (cmds-check.c:13031) ==31890== by 0x40A88A: main (btrfs.c:246) ==31890== Block was alloc'd at ==31890== at 0x4C2AF1F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==31890== by 0x45055C: get_inode_backref (cmds-check.c:1075) ==31890== by 0x45055C: add_inode_backref (cmds-check.c:1097) ==31890== by 0x45180C: process_dir_item (cmds-check.c:1525) ==31890== by 0x45180C: process_one_leaf (cmds-check.c:1838) ==31890== by 0x45180C: walk_down_tree (cmds-check.c:2134) ==31890== by 0x45180C: check_fs_root (cmds-check.c:3957) ==31890== by 0x45E788: check_fs_roots (cmds-check.c:4098) ==31890== by 0x45E788: cmd_check (cmds-check.c:13031) ==31890== by 0x40A88A: main (btrfs.c:246) ==31890== ==31890== Invalid read of size 8 ==31890== at 0x452D66: repair_inode_backrefs (cmds-check.c:2731) ==31890== by 0x452D66: check_inode_recs (cmds-check.c:3330) ==31890== by 0x452D66: check_fs_root (cmds-check.c:4012) ==31890== by 0x45E788: check_fs_roots (cmds-check.c:4098) ==31890== by 0x45E788: cmd_check (cmds-check.c:13031) ==31890== by 0x40A88A: main (btrfs.c:246) ==31890== Address 0x5cb7b90 is 16 bytes inside a block of size 50 free'd ==31890== at 0x4C2C14B: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==31890== by 0x453D08: repair_inode_backrefs (cmds-check.c:2684) ==31890== by 0x453D08: check_inode_recs (cmds-check.c:3330) ==31890== by 0x453D08: check_fs_root (cmds-check.c:4012) ==31890== by 0x45E788: check_fs_roots (cmds-check.c:4098) ==31890== by 0x45E788: cmd_check (cmds-check.c:13031) ==31890== by 0x40A88A: main (btrfs.c:246) ==31890== Block was alloc'd at ==31890== at 0x4C2AF1F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==31890== by 0x45055C: get_inode_backref (cmds-check.c:1075) ==31890== by 0x45055C: add_inode_backref (cmds-check.c:1097) ==31890== by 0x45180C: process_dir_item (cmds-check.c:1525) ==31890== by 0x45180C: process_one_leaf (cmds-check.c:1838) ==31890== by 0x45180C: walk_down_tree (cmds-check.c:2134) ==31890== by 0x45180C: check_fs_root (cmds-check.c:3957) ==31890== by 0x45E788: check_fs_roots (cmds-check.c:4098) ==31890== by 0x45E788: cmd_check (cmds-check.c:13031) ==31890== by 0x40A88A: main (btrfs.c:246) ==31890== The repair_inode_backrefs use the backref again after free while iterating over backrefs. So let it continue to next step after free can fix it. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> --- cmds-check.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)