From d8ae4601a4b7ea1fa17fa395c3468c0e144d1275 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 28 Feb 2009 09:50:01 -0500 Subject: ext4: Reorder fs/Makefile so that ext2 root fs's are mounted using ext2 In fs/Makefile, ext3 was placed before ext2 so that a root filesystem that possessed a journal, it would be mounted as ext3 instead of ext2. This was necessary because a cleanly unmounted ext3 filesystem was fully backwards compatible with ext2, and could be mounted by ext2 --- but it was desirable that it be mounted with ext3 so that the journaling would be enabled. The ext4 filesystem supports new incompatible features, so there is no danger of an ext4 filesystem being mistaken for an ext2 filesystem. At that point, the relative ordering of ext4 with respect to ext2 didn't matter until ext4 gained the ability to mount filesystems without a journal starting in 2.6.29-rc1. Now that this is the case, given that ext4 is before ext2, it means that root filesystems that were using the plain-jane ext2 format are getting mounted using the ext4 filesystem driver, which is a change in behavior which could be surprising to users. It's doubtful that there are that many ext2-only root filesystem users that would also have ext4 compiled into the kernel, but to adhere to the principle of least surprise, the correct ordering in fs/Makefile is ext3, followed by ext2, and finally ext4. Signed-off-by: "Theodore Ts'o" --- fs/Makefile | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'fs/Makefile') diff --git a/fs/Makefile b/fs/Makefile index 38bc735c67a..dc20db34867 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -69,10 +69,12 @@ obj-$(CONFIG_DLM) += dlm/ # Do not add any filesystems before this line obj-$(CONFIG_REISERFS_FS) += reiserfs/ obj-$(CONFIG_EXT3_FS) += ext3/ # Before ext2 so root fs can be ext3 -obj-$(CONFIG_EXT4_FS) += ext4/ # Before ext2 so root fs can be ext4 +obj-$(CONFIG_EXT2_FS) += ext2/ +# We place ext4 after ext2 so plain ext2 root fs's are mounted using ext2 +# unless explicitly requested by rootfstype +obj-$(CONFIG_EXT4_FS) += ext4/ obj-$(CONFIG_JBD) += jbd/ obj-$(CONFIG_JBD2) += jbd2/ -obj-$(CONFIG_EXT2_FS) += ext2/ obj-$(CONFIG_CRAMFS) += cramfs/ obj-$(CONFIG_SQUASHFS) += squashfs/ obj-y += ramfs/ -- cgit v1.2.3-18-g5258