Hi all, Here's a short patch series that rolls up all my pending fixes for assorted minor problems with ext2, ext4, and jbd2. It then introduces the "metdata_csum_seed" feature which decouples the metadata block checksums from the FS UUID so that said UUID can be changed while the FS is mounted; finally, it replaces all the open coded feature flag functions with a series of helper functions. The first patch fixes a crash in the journal checksumming code where if the journal checksum feature flag gets turned on after the journal loads, a missing checksum function context results in a crash. Generally this only happens if you have bad memory or something overwrites the mounted filesystem. This fixes a bug reported by Nikolay Borisov. Patches 2-3 move ext4 ahead of ext2 in the default probing order and teaches ext2 not to rw mount a filesystem with a journal if ext4 is available. Anyone wishing to force usage of ext2.ko for an ext2 filesystem when ext4 is present must use "mount -t ext2" or "rootfstype=ext2". This fixes a bug reported by Dave Chinner. Patch 4 introduces the metadata_csum_seed feature, which saves the first component of metadata block checksums (specifically, the value of crc32c(~0, FS_UUID)) in the superblock. This enables the administrator to change the UUID on a mounted metadata_csum filesystem. Patches 5-6 change ext4 to return error codes of EFSBADCRC for failed CRC verification and EFSCORRUPTED for data structures that look incorrect. This mimics the behavior of XFS. Patches 7-8 replace open-coded feature flag manipulation code with helper functions. I've hand-checked all the changes to ensure that they are correct. The patchset should apply cleanly against 4.3-rc5. Comments and questions are, as always, welcome. --D -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
