Re: [BUG] ext3/ext4 migration problem with dir_nlink feature flag
From: Akira Fujita <hidden>
Date: 2011-01-21 07:34:46
Attachments
- dir_nlink.sh [application/x-shellscript] 1313 bytes · preview
From: Akira Fujita <hidden>
Date: 2011-01-21 07:34:46
Hi, Unfortunately, this bug still exists in 2.6.38-rc1 with e2fsprogs-1.41.13. Attached test program can reproduce this bug easily. Please have a look and try. Regards, Akira Fujita (2010/10/06 11:44), Akira Fujita wrote:
Hi, I found a bug which returns EIO by file access on ext3 (was ext4) whose dir_nlink feature flag is removed and has more than 64000 directories. Kernel: 2.6.36-rc6, e2fsprogs: 1.41.2 Steps to reproduce are as follows: 1. Create ext4 which does not have extent and flex_bg feature flags (Because this fs will be mounted as ext3 in step 3), then create more than 64000 directories. Therefore dir_nlink feature flag is set and link count becomes 1. 2. Remove dir_nlink feature flag with tune2fs command (e.g. tune2fs -O ^dir_nlink /dev/sdx). 3. Mount ext4 as ext3, then remove subdir (Link: 1->0). We cannot access parent directory, because link count goes wrong. We should disallow tune2fs command to remove dir_nlink feature flag. Regards, Akira Fujita -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html