This is a note to let you know that I've just added the patch titled
ext4: set csum seed in tmp inode while migrating to extents
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-set-csum-seed-in-tmp-inode-while-migrating-to-extents.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e81c9302a6c3c008f5c30beb73b38adb0170ff2d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lu=C3=ADs=20Henriques?= <lhenriques@xxxxxxx>
Date: Tue, 14 Dec 2021 17:50:58 +0000
Subject: ext4: set csum seed in tmp inode while migrating to extents
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From: Luís Henriques <lhenriques@xxxxxxx>
commit e81c9302a6c3c008f5c30beb73b38adb0170ff2d upstream.
When migrating to extents, the temporary inode will have it's own checksum
seed. This means that, when swapping the inodes data, the inode checksums
will be incorrect.
This can be fixed by recalculating the extents checksums again. Or simply
by copying the seed into the temporary inode.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=213357
Reported-by: Jeroen van Wolffelaar <jeroen@xxxxxxxxxxxxx>
Signed-off-by: Luís Henriques <lhenriques@xxxxxxx>
Link: https://lore.kernel.org/r/20211214175058.19511-1-lhenriques@xxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Cc: stable@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/migrate.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -484,6 +484,17 @@ int ext4_ext_migrate(struct inode *inode
ext4_journal_stop(handle);
goto out_unlock;
}
+ /*
+ * Use the correct seed for checksum (i.e. the seed from 'inode'). This
+ * is so that the metadata blocks will have the correct checksum after
+ * the migration.
+ *
+ * Note however that, if a crash occurs during the migration process,
+ * the recovery process is broken because the tmp_inode checksums will
+ * be wrong and the orphans cleanup will fail.
+ */
+ ei = EXT4_I(inode);
+ EXT4_I(tmp_inode)->i_csum_seed = ei->i_csum_seed;
i_size_write(tmp_inode, i_size_read(inode));
/*
* Set the i_nlink to zero so it will be deleted later
@@ -527,7 +538,6 @@ int ext4_ext_migrate(struct inode *inode
goto out_tmp_inode;
}
- ei = EXT4_I(inode);
i_data = ei->i_data;
memset(&lb, 0, sizeof(lb));
Patches currently in stable-queue which might be from lhenriques@xxxxxxx are
queue-4.14/ext4-set-csum-seed-in-tmp-inode-while-migrating-to-extents.patch
