[PATCHv2 1/5] ext4: Fix error handling in ext4_restore_inline_data()

From: Ritesh Harjani
Date: Mon Jan 17 2022 - 07:12:20 EST


While running "./check -I 200 generic/475" it sometimes gives below
kernel BUG(). Ideally we should not call ext4_write_inline_data() if
ext4_create_inline_data() has failed.

<log snip>
[73131.453234] kernel BUG at fs/ext4/inline.c:223!

<code snip>
212 static void ext4_write_inline_data(struct inode *inode, struct ext4_iloc *iloc,
213 void *buffer, loff_t pos, unsigned int len)
214 {
<...>
223 BUG_ON(!EXT4_I(inode)->i_inline_off);
224 BUG_ON(pos + len > EXT4_I(inode)->i_inline_size);

This patch handles the error and prints out a emergency msg saying potential
data loss for the given inode (since we couldn't restore the original
inline_data due to some previous error).

[ 9571.070313] EXT4-fs (dm-0): error restoring inline_data for inode -- potential data loss! (inode 1703982, error -30)

Reported-by: Eric Whitney <enwlinux@xxxxxxxxx>
Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
---
fs/ext4/inline.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 39a1ab129fdc..d091133a4b46 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1133,7 +1133,15 @@ static void ext4_restore_inline_data(handle_t *handle, struct inode *inode,
struct ext4_iloc *iloc,
void *buf, int inline_size)
{
- ext4_create_inline_data(handle, inode, inline_size);
+ int ret;
+
+ ret = ext4_create_inline_data(handle, inode, inline_size);
+ if (ret) {
+ ext4_msg(inode->i_sb, KERN_EMERG,
+ "error restoring inline_data for inode -- potential data loss! (inode %lu, error %d)",
+ inode->i_ino, ret);
+ return;
+ }
ext4_write_inline_data(inode, iloc, buf, 0, inline_size);
ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA);
}
--
2.31.1