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See http://www.infradead.org/rpr.html On Mon, Mar 02, 2026 at 10:51:03AM +0800, Jiucheng Xu via B4 Relay wrote: > From: Jiucheng Xu > > When current->bio_list is non-NULL in submit_bio_wait(), > submit_bio_noacct_nocheck appends bio to bio_list but skips IO > submission, causing submit_bio_wait() to hang indefinitely. > > Fix this by temporarily backup bio_list, setting bio_list to > NULL before calling submit_bio(), then restoring bio_list > after submit_bio() returns. No. Fix this by not doing something that is a bad idea. > I've trimmed down the call stack, as follows: > > f2fs_submit_read_io > submit_bio > mmc_blk_mq_recovery > z_erofs_endio > vm_map_ram ->bi_end_io code really should not be having random in_atomic() checks that make it completely different, but even if they have that need to use GFP_NOIO.