| Message ID | 20200217181653.4706-3-vgoyal@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | dax/pmem: Provide a dax operation to zero range of memory | expand |
On Mon, Feb 17, 2020 at 01:16:48PM -0500, Vivek Goyal wrote: > Currently pmem_do_write() is written with assumption that all I/O is > sector aligned. Soon I want to use this function in zero_page_range() > where range passed in does not have to be sector aligned. > > Modify this function to be able to deal with an arbitrary range. Which > is specified by pmem_off and len. > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > --- > drivers/nvdimm/pmem.c | 32 +++++++++++++++++++++++--------- > 1 file changed, 23 insertions(+), 9 deletions(-) > > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c > index 075b11682192..fae8f67da9de 100644 > --- a/drivers/nvdimm/pmem.c > +++ b/drivers/nvdimm/pmem.c > @@ -154,15 +154,23 @@ static blk_status_t pmem_do_read(struct pmem_device *pmem, > > static blk_status_t pmem_do_write(struct pmem_device *pmem, > struct page *page, unsigned int page_off, > - sector_t sector, unsigned int len) > + u64 pmem_off, unsigned int len) > { > blk_status_t rc = BLK_STS_OK; > bool bad_pmem = false; > - phys_addr_t pmem_off = sector * 512 + pmem->data_offset; > - void *pmem_addr = pmem->virt_addr + pmem_off; > - > - if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) > - bad_pmem = true; > + phys_addr_t pmem_real_off = pmem_off + pmem->data_offset; > + void *pmem_addr = pmem->virt_addr + pmem_real_off; > + sector_t sector_start, sector_end; > + unsigned nr_sectors; > + > + sector_start = DIV_ROUND_UP(pmem_off, SECTOR_SIZE); > + sector_end = (pmem_off + len) >> SECTOR_SHIFT; > + if (sector_end > sector_start) { > + nr_sectors = sector_end - sector_start; > + if (is_bad_pmem(&pmem->bb, sector_start, > + nr_sectors << SECTOR_SHIFT)) > + bad_pmem = true; > + } > > /* > * Note that we write the data both before and after > @@ -181,7 +189,13 @@ static blk_status_t pmem_do_write(struct pmem_device *pmem, > flush_dcache_page(page); > write_pmem(pmem_addr, page, page_off, len); > if (unlikely(bad_pmem)) { > - rc = pmem_clear_poison(pmem, pmem_off, len); > + /* > + * Pass sector aligned offset and length. That seems > + * to work as of now. Other finer grained alignment > + * cases can be addressed later if need be. > + */ > + rc = pmem_clear_poison(pmem, ALIGN(pmem_real_off, SECTOR_SIZE), > + nr_sectors << SECTOR_SHIFT); > write_pmem(pmem_addr, page, page_off, len); I'm still scared about the as of now commnet. If the interface to clearing poison is page aligned I think we should document that in the actual pmem_clear_poison function, and make that take the unaligned offset. I also think we want some feedback from Dan or other what the official interface is instead of "seems to work".
On Tue, Feb 18, 2020 at 09:09:28AM -0800, Christoph Hellwig wrote: > On Mon, Feb 17, 2020 at 01:16:48PM -0500, Vivek Goyal wrote: > > Currently pmem_do_write() is written with assumption that all I/O is > > sector aligned. Soon I want to use this function in zero_page_range() > > where range passed in does not have to be sector aligned. > > > > Modify this function to be able to deal with an arbitrary range. Which > > is specified by pmem_off and len. > > > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > > --- > > drivers/nvdimm/pmem.c | 32 +++++++++++++++++++++++--------- > > 1 file changed, 23 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c > > index 075b11682192..fae8f67da9de 100644 > > --- a/drivers/nvdimm/pmem.c > > +++ b/drivers/nvdimm/pmem.c > > @@ -154,15 +154,23 @@ static blk_status_t pmem_do_read(struct pmem_device *pmem, > > > > static blk_status_t pmem_do_write(struct pmem_device *pmem, > > struct page *page, unsigned int page_off, > > - sector_t sector, unsigned int len) > > + u64 pmem_off, unsigned int len) > > { > > blk_status_t rc = BLK_STS_OK; > > bool bad_pmem = false; > > - phys_addr_t pmem_off = sector * 512 + pmem->data_offset; > > - void *pmem_addr = pmem->virt_addr + pmem_off; > > - > > - if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) > > - bad_pmem = true; > > + phys_addr_t pmem_real_off = pmem_off + pmem->data_offset; > > + void *pmem_addr = pmem->virt_addr + pmem_real_off; > > + sector_t sector_start, sector_end; > > + unsigned nr_sectors; > > + > > + sector_start = DIV_ROUND_UP(pmem_off, SECTOR_SIZE); > > + sector_end = (pmem_off + len) >> SECTOR_SHIFT; > > + if (sector_end > sector_start) { > > + nr_sectors = sector_end - sector_start; > > + if (is_bad_pmem(&pmem->bb, sector_start, > > + nr_sectors << SECTOR_SHIFT)) > > + bad_pmem = true; > > + } > > > > /* > > * Note that we write the data both before and after > > @@ -181,7 +189,13 @@ static blk_status_t pmem_do_write(struct pmem_device *pmem, > > flush_dcache_page(page); > > write_pmem(pmem_addr, page, page_off, len); > > if (unlikely(bad_pmem)) { > > - rc = pmem_clear_poison(pmem, pmem_off, len); > > + /* > > + * Pass sector aligned offset and length. That seems > > + * to work as of now. Other finer grained alignment > > + * cases can be addressed later if need be. > > + */ > > + rc = pmem_clear_poison(pmem, ALIGN(pmem_real_off, SECTOR_SIZE), > > + nr_sectors << SECTOR_SHIFT); > > write_pmem(pmem_addr, page, page_off, len); > > I'm still scared about the as of now commnet. If the interface to > clearing poison is page aligned I think we should document that in the > actual pmem_clear_poison function, and make that take the unaligned > offset. I also think we want some feedback from Dan or other what the > official interface is instead of "seems to work". Ok, I am adding one more patch to series and enabling pmem_clear_poison() to accept arbitrary offset and length and let it align offset and length to sector boundary. Keeping it in a separate patch so that Dan can have a close look at it and make sure I am doing things correctly. Here is the new patch. I will post the V5 soon with this new patch. Thanks Vivek Subject: drivers/pmem: Allow pmem_clear_poison() to accept arbitrary offset and len Currently pmem_clear_poison() expects offset and len to be sector aligned. Atleast that seems to be the assumption with which code has been written. It is called only from pmem_do_bvec() which is called only from pmem_rw_page() and pmem_make_request() which will only passe sector aligned offset and len. Soon we want use this function from dax_zero_page_range() code path which can try to zero arbitrary range of memory with-in a page. So update this function to assume that offset and length can be arbitrary and do the necessary alignments as needed. nvdimm_clear_poison() seems to assume offset and len to be aligned to clear_err_unit boundary. But this is currently internal detail and is not exported for others to use. So for now, continue to align offset and length to SECTOR_SIZE boundary. Improving it further and to align it to clear_err_unit boundary is a TODO item for future. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- drivers/nvdimm/pmem.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 075b11682192..e72959203253 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -74,14 +74,28 @@ static blk_status_t pmem_clear_poison(struct pmem_device *pmem, sector_t sector; long cleared; blk_status_t rc = BLK_STS_OK; + phys_addr_t start_aligned, end_aligned; + unsigned int len_aligned; - sector = (offset - pmem->data_offset) / 512; + /* + * Callers can pass arbitrary offset and len. But nvdimm_clear_poison() + * expects memory offset and length to meet certain alignment + * restrction (clear_err_unit). Currently nvdimm does not export + * required alignment. So align offset and length to sector boundary + * before passing it to nvdimm_clear_poison(). + */ + start_aligned = ALIGN(offset, SECTOR_SIZE); + end_aligned = ALIGN_DOWN((offset + len), SECTOR_SIZE) - 1; + len_aligned = end_aligned - start_aligned + 1; + + sector = (start_aligned - pmem->data_offset) / 512; - cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len); - if (cleared < len) + cleared = nvdimm_clear_poison(dev, pmem->phys_addr + start_aligned, + len_aligned); + if (cleared < len_aligned) rc = BLK_STS_IOERR; if (cleared > 0 && cleared / 512) { - hwpoison_clear(pmem, pmem->phys_addr + offset, cleared); + hwpoison_clear(pmem, pmem->phys_addr + start_aligned, cleared); cleared /= 512; dev_dbg(dev, "%#llx clear %ld sector%s\n", (unsigned long long) sector, cleared,
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 075b11682192..fae8f67da9de 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -154,15 +154,23 @@ static blk_status_t pmem_do_read(struct pmem_device *pmem, static blk_status_t pmem_do_write(struct pmem_device *pmem, struct page *page, unsigned int page_off, - sector_t sector, unsigned int len) + u64 pmem_off, unsigned int len) { blk_status_t rc = BLK_STS_OK; bool bad_pmem = false; - phys_addr_t pmem_off = sector * 512 + pmem->data_offset; - void *pmem_addr = pmem->virt_addr + pmem_off; - - if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) - bad_pmem = true; + phys_addr_t pmem_real_off = pmem_off + pmem->data_offset; + void *pmem_addr = pmem->virt_addr + pmem_real_off; + sector_t sector_start, sector_end; + unsigned nr_sectors; + + sector_start = DIV_ROUND_UP(pmem_off, SECTOR_SIZE); + sector_end = (pmem_off + len) >> SECTOR_SHIFT; + if (sector_end > sector_start) { + nr_sectors = sector_end - sector_start; + if (is_bad_pmem(&pmem->bb, sector_start, + nr_sectors << SECTOR_SHIFT)) + bad_pmem = true; + } /* * Note that we write the data both before and after @@ -181,7 +189,13 @@ static blk_status_t pmem_do_write(struct pmem_device *pmem, flush_dcache_page(page); write_pmem(pmem_addr, page, page_off, len); if (unlikely(bad_pmem)) { - rc = pmem_clear_poison(pmem, pmem_off, len); + /* + * Pass sector aligned offset and length. That seems + * to work as of now. Other finer grained alignment + * cases can be addressed later if need be. + */ + rc = pmem_clear_poison(pmem, ALIGN(pmem_real_off, SECTOR_SIZE), + nr_sectors << SECTOR_SHIFT); write_pmem(pmem_addr, page, page_off, len); } @@ -206,7 +220,7 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) bio_for_each_segment(bvec, bio, iter) { if (op_is_write(bio_op(bio))) rc = pmem_do_write(pmem, bvec.bv_page, bvec.bv_offset, - iter.bi_sector, bvec.bv_len); + iter.bi_sector << SECTOR_SHIFT, bvec.bv_len); else rc = pmem_do_read(pmem, bvec.bv_page, bvec.bv_offset, iter.bi_sector, bvec.bv_len); @@ -235,7 +249,7 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector, blk_status_t rc; if (op_is_write(op)) - rc = pmem_do_write(pmem, page, 0, sector, + rc = pmem_do_write(pmem, page, 0, sector << SECTOR_SHIFT, hpage_nr_pages(page) * PAGE_SIZE); else rc = pmem_do_read(pmem, page, 0, sector,
Currently pmem_do_write() is written with assumption that all I/O is sector aligned. Soon I want to use this function in zero_page_range() where range passed in does not have to be sector aligned. Modify this function to be able to deal with an arbitrary range. Which is specified by pmem_off and len. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- drivers/nvdimm/pmem.c | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-)