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ext4: prevent partial update of the extents path

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In ext4_ext_rm_idx() and ext4_ext_correct_indexes(), there is no proper
rollback of already executed updates when updating a level of the extents
path fails, so we may get an inconsistent extents tree, which may trigger
some bad things in errors=continue mode.

Hence clear the verified bit of modified extents buffers if the tree fails
to be updated in ext4_ext_rm_idx() or ext4_ext_correct_indexes(), which
forces the extents buffers to be checked in ext4_valid_extent_entries(),
ensuring that the extents tree is consistent.

Signed-off-by: zhanchengbin <zhanchengbin1@huawei.com>
Link: https://lore.kernel.org/r/20230213080514.535568-3-zhanchengbin1@huawei.com/
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20240822023545.1994557-3-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Baokun Li
2024-08-22 10:35:22 +08:00
committed by Theodore Ts'o
parent edfa71dbe8
commit 3e8a584c82
1 changed files with 27 additions and 4 deletions
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31
fs/ext4/extents.c
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@@ -1749,12 +1749,23 @@ static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
break;
err = ext4_ext_get_access(handle, inode, path + k);
if (err)
break;
goto clean;
path[k].p_idx->ei_block = border;
err = ext4_ext_dirty(handle, inode, path + k);
if (err)
break;
goto clean;
}
return 0;
clean:
/*
* The path[k].p_bh is either unmodified or with no verified bit
* set (see ext4_ext_get_access()). So just clear the verified bit
* of the successfully modified extents buffers, which will force
* these extents to be checked to avoid using inconsistent data.
*/
while (++k < depth)
clear_buffer_verified(path[k].p_bh);
return err;
}
@@ -2312,12 +2323,24 @@ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
break;
err = ext4_ext_get_access(handle, inode, path + k);
if (err)
break;
goto clean;
path[k].p_idx->ei_block = path[k + 1].p_idx->ei_block;
err = ext4_ext_dirty(handle, inode, path + k);
if (err)
break;
goto clean;
}
return 0;
clean:
/*
* The path[k].p_bh is either unmodified or with no verified bit
* set (see ext4_ext_get_access()). So just clear the verified bit
* of the successfully modified extents buffers, which will force
* these extents to be checked to avoid using inconsistent data.
*/
while (++k < depth)
clear_buffer_verified(path[k].p_bh);
return err;
}