| Message ID | 20220222155156.597597-7-hch@lst.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [01/10] iss-simdisk: use bvec_kmap_local in simdisk_submit_bio | expand |
On Tue, Feb 22, 2022 at 04:51:52PM +0100, Christoph Hellwig wrote: > Using local kmaps slightly reduces the chances to stray writes, and > the bvec interface cleans up the code a little bit. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/nvdimm/btt.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c > index cbd994f7f1fe6..9613e54c7a675 100644 > --- a/drivers/nvdimm/btt.c > +++ b/drivers/nvdimm/btt.c > @@ -1163,17 +1163,15 @@ static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip, > */ > > cur_len = min(len, bv.bv_len); > - mem = kmap_atomic(bv.bv_page); > + mem = bvec_kmap_local(&bv); > if (rw) > - ret = arena_write_bytes(arena, meta_nsoff, > - mem + bv.bv_offset, cur_len, > + ret = arena_write_bytes(arena, meta_nsoff, mem, cur_len, Why drop bv.bv_offset here and below? Ira > NVDIMM_IO_ATOMIC); > else > - ret = arena_read_bytes(arena, meta_nsoff, > - mem + bv.bv_offset, cur_len, > + ret = arena_read_bytes(arena, meta_nsoff, mem, cur_len, > NVDIMM_IO_ATOMIC); > > - kunmap_atomic(mem); > + kunmap_local(mem); > if (ret) > return ret; > > -- > 2.30.2 > >
On Mon, Feb 28, 2022 at 07:59:06PM -0800, Ira Weiny wrote: > On Tue, Feb 22, 2022 at 04:51:52PM +0100, Christoph Hellwig wrote: > > Using local kmaps slightly reduces the chances to stray writes, and > > the bvec interface cleans up the code a little bit. > > > > Signed-off-by: Christoph Hellwig <hch@lst.de> > > --- > > drivers/nvdimm/btt.c | 10 ++++------ > > 1 file changed, 4 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c > > index cbd994f7f1fe6..9613e54c7a675 100644 > > --- a/drivers/nvdimm/btt.c > > +++ b/drivers/nvdimm/btt.c > > @@ -1163,17 +1163,15 @@ static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip, > > */ > > > > cur_len = min(len, bv.bv_len); > > - mem = kmap_atomic(bv.bv_page); > > + mem = bvec_kmap_local(&bv); > > if (rw) > > - ret = arena_write_bytes(arena, meta_nsoff, > > - mem + bv.bv_offset, cur_len, > > + ret = arena_write_bytes(arena, meta_nsoff, mem, cur_len, > > Why drop bv.bv_offset here and below? Because bvec_kmap_local includes bv_offset in the pointer that it returns.
On Tue, Mar 01, 2022 at 01:20:42PM +0100, Christoph Hellwig wrote: > On Mon, Feb 28, 2022 at 07:59:06PM -0800, Ira Weiny wrote: > > On Tue, Feb 22, 2022 at 04:51:52PM +0100, Christoph Hellwig wrote: > > > Using local kmaps slightly reduces the chances to stray writes, and > > > the bvec interface cleans up the code a little bit. > > > > > > Signed-off-by: Christoph Hellwig <hch@lst.de> > > > --- > > > drivers/nvdimm/btt.c | 10 ++++------ > > > 1 file changed, 4 insertions(+), 6 deletions(-) > > > > > > diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c > > > index cbd994f7f1fe6..9613e54c7a675 100644 > > > --- a/drivers/nvdimm/btt.c > > > +++ b/drivers/nvdimm/btt.c > > > @@ -1163,17 +1163,15 @@ static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip, > > > */ > > > > > > cur_len = min(len, bv.bv_len); > > > - mem = kmap_atomic(bv.bv_page); > > > + mem = bvec_kmap_local(&bv); > > > if (rw) > > > - ret = arena_write_bytes(arena, meta_nsoff, > > > - mem + bv.bv_offset, cur_len, > > > + ret = arena_write_bytes(arena, meta_nsoff, mem, cur_len, > > > > Why drop bv.bv_offset here and below? > > Because bvec_kmap_local includes bv_offset in the pointer that it > returns. Ah I missed that. Thanks, Ira
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index cbd994f7f1fe6..9613e54c7a675 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1163,17 +1163,15 @@ static int btt_rw_integrity(struct btt *btt, struct bio_integrity_payload *bip, */ cur_len = min(len, bv.bv_len); - mem = kmap_atomic(bv.bv_page); + mem = bvec_kmap_local(&bv); if (rw) - ret = arena_write_bytes(arena, meta_nsoff, - mem + bv.bv_offset, cur_len, + ret = arena_write_bytes(arena, meta_nsoff, mem, cur_len, NVDIMM_IO_ATOMIC); else - ret = arena_read_bytes(arena, meta_nsoff, - mem + bv.bv_offset, cur_len, + ret = arena_read_bytes(arena, meta_nsoff, mem, cur_len, NVDIMM_IO_ATOMIC); - kunmap_atomic(mem); + kunmap_local(mem); if (ret) return ret;
Using local kmaps slightly reduces the chances to stray writes, and the bvec interface cleans up the code a little bit. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/nvdimm/btt.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)