| Message ID | 20210525212501.226888-1-damien.lemoal@wdc.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | dm: Improve zoned block device support | expand |
On 2021/05/26 6:25, Damien Le Moal wrote: > This series improve device mapper support for zoned block devices and > of targets exposing a zoned device. Mike, Jens, Any feedback regarding this series ? > > The first patch improve support for user requests to reset all zones of > the target device. With the fix, such operation behave similarly to > physical block devices implementation based on the single zone reset > command with the ALL bit set. > > The following 2 patches are preparatory block layer patches. > > Patch 4 and 5 are 2 small fixes to DM core zoned block device support. > > Patch 6 reorganizes DM core code, moving conditionally defined zoned > block device code into the new dm-zone.c file. This avoids sprinkly DM > with zone related code defined under an #ifdef CONFIG_BLK_DEV_ZONED. > > Patch 7 improves DM zone report helper functions for target drivers. > > Patch 8 fixes a potential problem with BIO requeue on zoned target. > > Finally, patch 9 to 11 implement zone append emulation using regular > writes for target drivers that cannot natively support this BIO type. > The only target currently needing this emulation is dm-crypt. With this > change, a zoned dm-crypt device behaves exactly like a regular zoned > block device, correctly executing user zone append BIOs. > > This series passes the following tests: > 1) zonefs tests on top of dm-crypt with a zoned nullblk device > 2) zonefs tests on top of dm-crypt+dm-linear with an SMR HDD > 3) btrfs fstests on top of dm-crypt with zoned nullblk devices. > > Comments are as always welcome. > > Changes from v4: > * Remove useless extra space in variable initialization in patch 1 > * Shorten dm_accept_partial_bio() documentation comment in patch 4 > * Added reviewed-by tags > > Changes from v3: > * Fixed missing variable initialization in > blkdev_zone_reset_all_emulated() in patch 1. > * Rebased on rc3 > * Added reviewed-by tags > > Changes from v2: > * Replace use of spinlock to protect the zone write pointer offset > array in patch 11 with READ_ONCE/WRITE_ONCE as suggested by Hannes. > * Added reviewed-by tags > > Changes from v1: > * Use Christoph proposed approach for patch 1 (split reset all > processing into different functions) > * Changed helpers introduced in patch 2 to remove the request_queue > argument > * Improve patch 3 commit message as suggested by Christoph (explaining > that the flag is a special case that cannot use a REQ_XXX flag) > * Changed DMWARN() into DMDEBUG in patch 11 as suggested by Milan > * Added reviewed-by tags > > Damien Le Moal (11): > block: improve handling of all zones reset operation > block: introduce bio zone helpers > block: introduce BIO_ZONE_WRITE_LOCKED bio flag > dm: Fix dm_accept_partial_bio() > dm: cleanup device_area_is_invalid() > dm: move zone related code to dm-zone.c > dm: Introduce dm_report_zones() > dm: Forbid requeue of writes to zones > dm: rearrange core declarations > dm: introduce zone append emulation > dm crypt: Fix zoned block device support > > block/blk-zoned.c | 119 +++++-- > drivers/md/Makefile | 4 + > drivers/md/dm-core.h | 65 ++++ > drivers/md/dm-crypt.c | 31 +- > drivers/md/dm-flakey.c | 7 +- > drivers/md/dm-linear.c | 7 +- > drivers/md/dm-table.c | 21 +- > drivers/md/dm-zone.c | 654 ++++++++++++++++++++++++++++++++++ > drivers/md/dm.c | 201 +++-------- > drivers/md/dm.h | 30 +- > include/linux/blk_types.h | 1 + > include/linux/blkdev.h | 12 + > include/linux/device-mapper.h | 9 +- > 13 files changed, 954 insertions(+), 207 deletions(-) > create mode 100644 drivers/md/dm-zone.c >
On Tue, Jun 01 2021 at 6:57P -0400, Damien Le Moal <Damien.LeMoal@wdc.com> wrote: > On 2021/05/26 6:25, Damien Le Moal wrote: > > This series improve device mapper support for zoned block devices and > > of targets exposing a zoned device. > > Mike, Jens, > > Any feedback regarding this series ? > > > > > The first patch improve support for user requests to reset all zones of > > the target device. With the fix, such operation behave similarly to > > physical block devices implementation based on the single zone reset > > command with the ALL bit set. > > > > The following 2 patches are preparatory block layer patches. > > > > Patch 4 and 5 are 2 small fixes to DM core zoned block device support. > > > > Patch 6 reorganizes DM core code, moving conditionally defined zoned > > block device code into the new dm-zone.c file. This avoids sprinkly DM > > with zone related code defined under an #ifdef CONFIG_BLK_DEV_ZONED. > > > > Patch 7 improves DM zone report helper functions for target drivers. > > > > Patch 8 fixes a potential problem with BIO requeue on zoned target. > > > > Finally, patch 9 to 11 implement zone append emulation using regular > > writes for target drivers that cannot natively support this BIO type. > > The only target currently needing this emulation is dm-crypt. With this > > change, a zoned dm-crypt device behaves exactly like a regular zoned > > block device, correctly executing user zone append BIOs. > > > > This series passes the following tests: > > 1) zonefs tests on top of dm-crypt with a zoned nullblk device > > 2) zonefs tests on top of dm-crypt+dm-linear with an SMR HDD > > 3) btrfs fstests on top of dm-crypt with zoned nullblk devices. > > > > Comments are as always welcome. I've picked up DM patches 4-8 because they didn't depend on the first 3 block patches. But I'm fine with picking up 1-3 if Jens provides his Acked-by. And then I can pickup the remaining DM patches 9-11. Thanks, Mike
On 6/2/21 12:32 PM, Mike Snitzer wrote: > On Tue, Jun 01 2021 at 6:57P -0400, > Damien Le Moal <Damien.LeMoal@wdc.com> wrote: > >> On 2021/05/26 6:25, Damien Le Moal wrote: >>> This series improve device mapper support for zoned block devices and >>> of targets exposing a zoned device. >> >> Mike, Jens, >> >> Any feedback regarding this series ? >> >>> >>> The first patch improve support for user requests to reset all zones of >>> the target device. With the fix, such operation behave similarly to >>> physical block devices implementation based on the single zone reset >>> command with the ALL bit set. >>> >>> The following 2 patches are preparatory block layer patches. >>> >>> Patch 4 and 5 are 2 small fixes to DM core zoned block device support. >>> >>> Patch 6 reorganizes DM core code, moving conditionally defined zoned >>> block device code into the new dm-zone.c file. This avoids sprinkly DM >>> with zone related code defined under an #ifdef CONFIG_BLK_DEV_ZONED. >>> >>> Patch 7 improves DM zone report helper functions for target drivers. >>> >>> Patch 8 fixes a potential problem with BIO requeue on zoned target. >>> >>> Finally, patch 9 to 11 implement zone append emulation using regular >>> writes for target drivers that cannot natively support this BIO type. >>> The only target currently needing this emulation is dm-crypt. With this >>> change, a zoned dm-crypt device behaves exactly like a regular zoned >>> block device, correctly executing user zone append BIOs. >>> >>> This series passes the following tests: >>> 1) zonefs tests on top of dm-crypt with a zoned nullblk device >>> 2) zonefs tests on top of dm-crypt+dm-linear with an SMR HDD >>> 3) btrfs fstests on top of dm-crypt with zoned nullblk devices. >>> >>> Comments are as always welcome. > > I've picked up DM patches 4-8 because they didn't depend on the first > 3 block patches. > > But I'm fine with picking up 1-3 if Jens provides his Acked-by. > And then I can pickup the remaining DM patches 9-11. I'm fine with 1-3, you can add my Acked-by to those.
On Thu, Jun 03 2021 at 1:46P -0400, Jens Axboe <axboe@kernel.dk> wrote: > On 6/2/21 12:32 PM, Mike Snitzer wrote: > > On Tue, Jun 01 2021 at 6:57P -0400, > > Damien Le Moal <Damien.LeMoal@wdc.com> wrote: > > > >> On 2021/05/26 6:25, Damien Le Moal wrote: > >>> This series improve device mapper support for zoned block devices and > >>> of targets exposing a zoned device. > >> > >> Mike, Jens, > >> > >> Any feedback regarding this series ? > >> > >>> > >>> The first patch improve support for user requests to reset all zones of > >>> the target device. With the fix, such operation behave similarly to > >>> physical block devices implementation based on the single zone reset > >>> command with the ALL bit set. > >>> > >>> The following 2 patches are preparatory block layer patches. > >>> > >>> Patch 4 and 5 are 2 small fixes to DM core zoned block device support. > >>> > >>> Patch 6 reorganizes DM core code, moving conditionally defined zoned > >>> block device code into the new dm-zone.c file. This avoids sprinkly DM > >>> with zone related code defined under an #ifdef CONFIG_BLK_DEV_ZONED. > >>> > >>> Patch 7 improves DM zone report helper functions for target drivers. > >>> > >>> Patch 8 fixes a potential problem with BIO requeue on zoned target. > >>> > >>> Finally, patch 9 to 11 implement zone append emulation using regular > >>> writes for target drivers that cannot natively support this BIO type. > >>> The only target currently needing this emulation is dm-crypt. With this > >>> change, a zoned dm-crypt device behaves exactly like a regular zoned > >>> block device, correctly executing user zone append BIOs. > >>> > >>> This series passes the following tests: > >>> 1) zonefs tests on top of dm-crypt with a zoned nullblk device > >>> 2) zonefs tests on top of dm-crypt+dm-linear with an SMR HDD > >>> 3) btrfs fstests on top of dm-crypt with zoned nullblk devices. > >>> > >>> Comments are as always welcome. > > > > I've picked up DM patches 4-8 because they didn't depend on the first > > 3 block patches. > > > > But I'm fine with picking up 1-3 if Jens provides his Acked-by. > > And then I can pickup the remaining DM patches 9-11. > > I'm fine with 1-3, you can add my Acked-by to those. Thanks, did so. Damien: I've staged this patchset in linux-next via the dm-5.14 branch of linux-dm.git Might look at optimizing the fast-path of __map_bio further, e.g. this leaves something to be desired considering how niche this all is: /* * Check if the IO needs a special mapping due to zone append emulation * on zoned target. In this case, dm_zone_map_bio() calls the target * map operation. */ if (dm_emulate_zone_append(io->md)) r = dm_zone_map_bio(tio); else r = ti->type->map(ti, clone); Does it make sense to split out a new CONFIG_ that encapsulates legacy zoned devices?
On 2021/06/04 7:16, Mike Snitzer wrote: > On Thu, Jun 03 2021 at 1:46P -0400, > Jens Axboe <axboe@kernel.dk> wrote: > >> On 6/2/21 12:32 PM, Mike Snitzer wrote: >>> On Tue, Jun 01 2021 at 6:57P -0400, >>> Damien Le Moal <Damien.LeMoal@wdc.com> wrote: >>> >>>> On 2021/05/26 6:25, Damien Le Moal wrote: >>>>> This series improve device mapper support for zoned block devices and >>>>> of targets exposing a zoned device. >>>> >>>> Mike, Jens, >>>> >>>> Any feedback regarding this series ? >>>> >>>>> >>>>> The first patch improve support for user requests to reset all zones of >>>>> the target device. With the fix, such operation behave similarly to >>>>> physical block devices implementation based on the single zone reset >>>>> command with the ALL bit set. >>>>> >>>>> The following 2 patches are preparatory block layer patches. >>>>> >>>>> Patch 4 and 5 are 2 small fixes to DM core zoned block device support. >>>>> >>>>> Patch 6 reorganizes DM core code, moving conditionally defined zoned >>>>> block device code into the new dm-zone.c file. This avoids sprinkly DM >>>>> with zone related code defined under an #ifdef CONFIG_BLK_DEV_ZONED. >>>>> >>>>> Patch 7 improves DM zone report helper functions for target drivers. >>>>> >>>>> Patch 8 fixes a potential problem with BIO requeue on zoned target. >>>>> >>>>> Finally, patch 9 to 11 implement zone append emulation using regular >>>>> writes for target drivers that cannot natively support this BIO type. >>>>> The only target currently needing this emulation is dm-crypt. With this >>>>> change, a zoned dm-crypt device behaves exactly like a regular zoned >>>>> block device, correctly executing user zone append BIOs. >>>>> >>>>> This series passes the following tests: >>>>> 1) zonefs tests on top of dm-crypt with a zoned nullblk device >>>>> 2) zonefs tests on top of dm-crypt+dm-linear with an SMR HDD >>>>> 3) btrfs fstests on top of dm-crypt with zoned nullblk devices. >>>>> >>>>> Comments are as always welcome. >>> >>> I've picked up DM patches 4-8 because they didn't depend on the first >>> 3 block patches. >>> >>> But I'm fine with picking up 1-3 if Jens provides his Acked-by. >>> And then I can pickup the remaining DM patches 9-11. >> >> I'm fine with 1-3, you can add my Acked-by to those. > > Thanks, did so. > > Damien: I've staged this patchset in linux-next via the dm-5.14 branch of linux-dm.git Thanks ! > Might look at optimizing the fast-path of __map_bio further, e.g. this > leaves something to be desired considering how niche this all is: > > /* > * Check if the IO needs a special mapping due to zone append emulation > * on zoned target. In this case, dm_zone_map_bio() calls the target > * map operation. > */ > if (dm_emulate_zone_append(io->md)) > r = dm_zone_map_bio(tio); > else > r = ti->type->map(ti, clone); > > Does it make sense to split out a new CONFIG_ that encapsulates legacy > zoned devices? Well, the problem is that there are no "legacy" zoned devices: they all support zone append commands, either natively (for zns and nullblk) or emulated in their respective drivers (scsi sd for SMR drives). So I do not think that a new CONFIG_XXX can be used. What we could do is have this conditional on either: (1) the DM targets that need it: dm-crypt only for now (CONFIG_DM_CRYPT) (2) Zone append command users: btrfs and zonefs only for now (CONFIG_FS_BTRFS and CONFIG_FS_ZONEFS) (1) would be the nicest as we can keep this contained in DM and define something in KConfig. However, given that most distros (if not all) enable dm-crypt, I am not convinced this will do any good. Note that for the !CONFIG_BLK_DEV_ZONED case, the "if (dm_emulate_zone_append(io->md))" is compiled out, resulting in the same code as without the emulation.