Messages in this thread |  | | Date | Tue, 31 Mar 2020 12:05:26 +0200 | From | Greg KH <> | Subject | Re: [PATCH v4] mtd: clear cache_state to avoid writing to bad blocks repeatedly |
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On Tue, Mar 31, 2020 at 09:31:59AM +0800, Xiaoming Ni wrote: > The function call process is as follows: > mtd_blktrans_work() > while (1) > do_blktrans_request() > mtdblock_writesect() > do_cached_write() > write_cached_data() /*if cache_state is STATE_DIRTY*/ > erase_write() > > write_cached_data() returns failure without modifying cache_state > and cache_offset. So when do_cached_write() is called again, > write_cached_data() will be called again to perform erase_write() > on the same cache_offset. > > But if this cache_offset points to a bad block, erase_write() will > always return -EIO. Writing to this mtdblk is equivalent to losing > the current data, and repeatedly writing to the bad block. > > Repeatedly writing a bad block has no real benefits, > but brings some negative effects: > 1 Lost subsequent data > 2 Loss of flash device life > 3 erase_write() bad blocks are very time-consuming. For example: > the function do_erase_oneblock() in chips/cfi_cmdset_0020.c or > chips/cfi_cmdset_0002.c may take more than 20 seconds to return > > Therefore, when erase_write() returns -EIO in write_cached_data(), > clear cache_state to avoid writing to bad blocks repeatedly. > > Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> > Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> > --- > drivers/mtd/mtdblock.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-)
$ ./scripts/get_maintainer.pl --file drivers/mtd/mtdblock.c Miquel Raynal <miquel.raynal@bootlin.com> (maintainer:MEMORY TECHNOLOGY DEVICES (MTD)) Richard Weinberger <richard@nod.at> (maintainer:MEMORY TECHNOLOGY DEVICES (MTD)) Vignesh Raghavendra <vigneshr@ti.com> (maintainer:MEMORY TECHNOLOGY DEVICES (MTD)) linux-mtd@lists.infradead.org (open list:MEMORY TECHNOLOGY DEVICES (MTD)) linux-kernel@vger.kernel.org (open list)
No where on there is my name/email, so why am I getting these?
confused,
greg k-h
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