From 0a2c984222d03d940c52c3675849dd6398b34e64 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Thu, 9 Aug 2018 22:45:26 +0200 Subject: [PATCH] kernel: ext4: fix check to prevent initializing reserved inodes The broken check would detect a newly generated root filesystem as corrupt under certain circumstances, in some cases actually currupting the it while trying to handle the error condition. This is a regression introduced in kernel 4.4.140. The 4.14.y stable series has already received this fix, while it is still pending for 4.4.y and 4.9.y. Signed-off-by: Matthias Schiffer --- ...o-prevent-initializing-reserved-inod.patch | 68 +++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 target/linux/generic/patches-4.4/005-ext4-fix-check-to-prevent-initializing-reserved-inod.patch diff --git a/target/linux/generic/patches-4.4/005-ext4-fix-check-to-prevent-initializing-reserved-inod.patch b/target/linux/generic/patches-4.4/005-ext4-fix-check-to-prevent-initializing-reserved-inod.patch new file mode 100644 index 0000000000..4d11892ce9 --- /dev/null +++ b/target/linux/generic/patches-4.4/005-ext4-fix-check-to-prevent-initializing-reserved-inod.patch @@ -0,0 +1,68 @@ +From 7cb53d379df849d843cfd658f351b79b41b09051 Mon Sep 17 00:00:00 2001 +Message-Id: <7cb53d379df849d843cfd658f351b79b41b09051.1533837011.git.mschiffer@universe-factory.net> +From: Theodore Ts'o +Date: Sat, 28 Jul 2018 08:12:04 -0400 +Subject: [PATCH] ext4: fix check to prevent initializing reserved inodes + +Commit 5012284700775a4e6e3fbe7eac4c543c4874b559 upstream. + +Commit 8844618d8aa7: "ext4: only look at the bg_flags field if it is +valid" will complain if block group zero does not have the +EXT4_BG_INODE_ZEROED flag set. Unfortunately, this is not correct, +since a freshly created file system has this flag cleared. It gets +almost immediately after the file system is mounted read-write --- but +the following somewhat unlikely sequence will end up triggering a +false positive report of a corrupted file system: + + mkfs.ext4 /dev/vdc + mount -o ro /dev/vdc /vdc + mount -o remount,rw /dev/vdc + +Instead, when initializing the inode table for block group zero, test +to make sure that itable_unused count is not too large, since that is +the case that will result in some or all of the reserved inodes +getting cleared. + +This fixes the failures reported by Eric Whiteney when running +generic/230 and generic/231 in the the nojournal test case. + +Fixes: 8844618d8aa7 ("ext4: only look at the bg_flags field if it is valid") +Reported-by: Eric Whitney +Signed-off-by: Theodore Ts'o +--- + fs/ext4/ialloc.c | 5 ++++- + fs/ext4/super.c | 8 +------- + 2 files changed, 5 insertions(+), 8 deletions(-) + +--- a/fs/ext4/ialloc.c ++++ b/fs/ext4/ialloc.c +@@ -1308,7 +1308,10 @@ int ext4_init_inode_table(struct super_b + ext4_itable_unused_count(sb, gdp)), + sbi->s_inodes_per_block); + +- if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group)) { ++ if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group) || ++ ((group == 0) && ((EXT4_INODES_PER_GROUP(sb) - ++ ext4_itable_unused_count(sb, gdp)) < ++ EXT4_FIRST_INO(sb)))) { + ext4_error(sb, "Something is wrong with group %u: " + "used itable blocks: %d; " + "itable unused count: %u", +--- a/fs/ext4/super.c ++++ b/fs/ext4/super.c +@@ -2875,14 +2875,8 @@ static ext4_group_t ext4_has_uninit_itab + if (!gdp) + continue; + +- if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)) +- continue; +- if (group != 0) ++ if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED))) + break; +- ext4_error(sb, "Inode table for bg 0 marked as " +- "needing zeroing"); +- if (sb->s_flags & MS_RDONLY) +- return ngroups; + } + + return group; -- 2.25.1