Messages in this thread | | | Date | Tue, 21 Nov 2023 23:28:56 -0800 | From | Christoph Hellwig <> | Subject | Re: [PATCH v3 2/3] block: introduce new field bd_flags in block_device |
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> + if (partno && bdev_flagged(disk->part0, BD_FLAG_HAS_SUBMIT_BIO)) > + bdev_set_flag(bdev, BD_FLAG_HAS_SUBMIT_BIO); > else > + bdev_clear_flag(bdev, BD_FLAG_HAS_SUBMIT_BIO);
While the block layer has a bit of history of using wrappers for testing, setting and clearing flags, I have to say I always find them rather confusing when reading the code.
> +#define BD_FLAG_READ_ONLY 0 /* read-only-policy */
I know this is copied from the existing field, but can you expand it a bit?
> +#define BD_FLAG_WRITE_HOLDER 1 > +#define BD_FLAG_HAS_SUBMIT_BIO 2 > +#define BD_FLAG_MAKE_IT_FAIL 3
And also write comments for these.
> + > struct block_device { > sector_t bd_start_sect; > sector_t bd_nr_sectors; > @@ -44,10 +49,8 @@ struct block_device { > struct request_queue * bd_queue; > struct disk_stats __percpu *bd_stats; > unsigned long bd_stamp; > - bool bd_read_only; /* read-only policy */ > + unsigned short bd_flags;
I suspect you really need an unsigned long and atomic bit ops here. Even a lock would probably not work on alpha as it could affect the other fields in the same 32-bit alignment.
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