On 2024/5/16 16:55, sunshijie wrote:
When thread A calls kill_f2fs_super, Thread A first executes the code
sbi->node_inode = NULL;
Then thread A may submit a bio to the function iput(sbi->meta_inode);
Then thread A enters the process D state,
Now that the bio submitted by thread A is complete, it calls f2fs_write_end_io
and may trigger null-ptr-deref in NODE_MAPPING.
I didn't get it, if there is no cp_err, f2fs_write_checkpoint() in
f2fs_put_super() will flush all dirty pages of node_inode, if there is
cp_err, below flow will keep all dirty pages being truncated, and
there is sanity check on all types of dirty pages.
/* our cp_error case, we can wait for any writeback page */
f2fs_flush_merged_writes(sbi);
f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA);
if (err || f2fs_cp_error(sbi)) {
truncate_inode_pages_final(NODE_MAPPING(sbi));
truncate_inode_pages_final(META_MAPPING(sbi));
}
for (i = 0; i < NR_COUNT_TYPE; i++) {
if (!get_pages(sbi, i))
continue;
f2fs_err(sbi, "detect filesystem reference count leak during "
"umount, type: %d, count: %lld", i, get_pages(sbi, i));
f2fs_bug_on(sbi, 1);
}
So, is there any missing case that dirty page of node_inode is missed by
f2fs_put_super()?
Thanks,
Thread A IRQ context
- f2fs_put_super
- sbi->node_inode = NULL;
- iput(sbi->meta_inode);
- iput_final
- write_inode_now
- writeback_single_inode
- __writeback_single_inode
- filemap_fdatawait
- filemap_fdatawait_range
- __kcfi_typeid_free_transhuge_page
- __filemap_fdatawait_range
- wait_on_page_writeback
- folio_wait_writeback
- folio_wait_bit
- folio_wait_bit_common
- io_schedule
- __handle_irq_event_percpu
- ufs_qcom_mcq_esi_handler
-
ufshcd_mcq_poll_cqe_nolock
- ufshcd_compl_one_cqe
- scsi_done
- scsi_done_internal
-
blk_mq_complete_request
- scsi_complete
- scsi_finish_command
- scsi_io_completion
- scsi_end_request
-
blk_update_request
- bio_endio
-
f2fs_write_end_io
-
NODE_MAPPING(sbi)
Signed-off-by: sunshijie <sunshi...@xiaomi.com>
---
fs/f2fs/super.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index adffc9b80a9c..aeb085e11f9a 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1641,12 +1641,12 @@ static void f2fs_put_super(struct super_block *sb)
f2fs_destroy_compress_inode(sbi);
- iput(sbi->node_inode);
- sbi->node_inode = NULL;
-
iput(sbi->meta_inode);
sbi->meta_inode = NULL;
+ iput(sbi->node_inode);
+ sbi->node_inode = NULL;
+
mutex_unlock(&sbi->umount_mutex);
/*
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
