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ext4: fix warning when submitting superblock in ext4_commit_super()

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We have already check the io_error and uptodate flag before submitting
the superblock buffer, and re-set the uptodate flag if it has been
failed to write out. But it was lockless and could be raced by another
ext4_commit_super(), and finally trigger '!uptodate' WARNING when
marking buffer dirty. Fix it by submit buffer directly.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20220520023216.3065073-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Zhang Yi 2022-05-20 10:32:16 +08:00 committed by Theodore Ts'o
parent 3103084afc
commit 15baa7dcad
1 changed files with 16 additions and 6 deletions
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22
fs/ext4/super.c
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@ -5898,7 +5898,6 @@ static void ext4_update_super(struct super_block *sb)
static int ext4_commit_super(struct super_block *sb)
{
struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
int error = 0;
if (!sbh)
return -EINVAL;
@ -5907,6 +5906,13 @@ static int ext4_commit_super(struct super_block *sb)
ext4_update_super(sb);
lock_buffer(sbh);
/* Buffer got discarded which means block device got invalidated */
if (!buffer_mapped(sbh)) {
unlock_buffer(sbh);
return -EIO;
}
if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
/*
* Oh, dear. A previous attempt to write the
@ -5921,17 +5927,21 @@ static int ext4_commit_super(struct super_block *sb)
clear_buffer_write_io_error(sbh);
set_buffer_uptodate(sbh);
}
BUFFER_TRACE(sbh, "marking dirty");
mark_buffer_dirty(sbh);
error = __sync_dirty_buffer(sbh,
REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
get_bh(sbh);
/* Clear potential dirty bit if it was journalled update */
clear_buffer_dirty(sbh);
sbh->b_end_io = end_buffer_write_sync;
submit_bh(REQ_OP_WRITE,
REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
wait_on_buffer(sbh);
if (buffer_write_io_error(sbh)) {
ext4_msg(sb, KERN_ERR, "I/O error while writing "
"superblock");
clear_buffer_write_io_error(sbh);
set_buffer_uptodate(sbh);
return -EIO;
}
return error;
return 0;
}
/*