From 9e680d0ada829f1cd7e2e1bff138d5e3ec32d0fd Mon Sep 17 00:00:00 2001 From: "Yann E. MORIN" Date: Sun, 5 Jan 2014 23:56:18 +0100 Subject: [PATCH] fs/ext2: fix generation of ext4 filesystems cset 7a58a4e (e2fsprogs: bump to version 1.42.9) broke the generation of ext4 filesystems. This is because, in ext4, some metadata are dependent on the UUID. If changing the UUID of an ext4 filesystem, tune2fs now exits with exit-code 1, and prints a message to run fsck, to avoid trashing the filesystem. This condition is of utmost importance on a mounted filesysten (which is not our case) to avoid corruption (yes, it is possible to change the UUID of a mounted filesystem). But the error is not valid for us, since we are working on an unmonted filesystem image in the first place. Since we change the UUID after we convert the filesystem (to ext4), tune2fs just bails out. We can not just ignore the exit code of tune2fs, since we still want to catch any other failure. It turns out that, changing the UUID before converting the filesystem is just the way to go. Fixes #6752. Reported-by: Daniel Mentz Signed-off-by: "Yann E. MORIN" Cc: Daniel Mentz Signed-off-by: Peter Korsgaard --- fs/ext2/genext2fs.sh | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/ext2/genext2fs.sh b/fs/ext2/genext2fs.sh index a6cd7d22b..6f7b07525 100755 --- a/fs/ext2/genext2fs.sh +++ b/fs/ext2/genext2fs.sh @@ -44,19 +44,21 @@ then fi e2tunefsck() { - # Upgrade the file system - if [ $# -ne 0 ]; then - tune2fs "$@" "${IMG}" - fi - # genext2fs does not generate a UUID, but fsck will whine if one is # is missing, so we need to add a UUID. # Of course, this has to happend _before_ we run fsck. + # Also, some ext4 metadata are based on the UUID, so we must + # set it before we can convert the filesystem to ext4. # Although a random UUID may seem bad for reproducibility, there # already are so many things that are not reproducible in a # filesystem: file dates, file ordering, content of the files... tune2fs -U random "${IMG}" + # Upgrade the filesystem + if [ $# -ne 0 ]; then + tune2fs "$@" "${IMG}" + fi + # After changing filesystem options, running fsck is required # (see: man tune2fs). Running e2fsck in other cases will ensure # coherency of the filesystem, although it is not required.