Messages in this thread | | | Subject | Re: [PATCH v4] mtd: clear cache_state to avoid writing to bad blocks repeatedly | From | Xiaoming Ni <> | Date | Tue, 31 Mar 2020 19:06:28 +0800 |
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On 2020/3/31 18:05, Greg KH wrote: > 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
At v3, I added Cc: stable@vger.kernel.org and emailed you, At v4, Cc: stable@vger.kernel.org was deleted, but forgot to remove you from the recipient list I'm very sorry to bother you Thanks Xiaoming Ni
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