| Message ID | 20221222175204.1782061-1-kbusch@meta.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: save user max_sectors limit | expand |
On Thu, Dec 22, 2022 at 09:52:04AM -0800, Keith Busch wrote: > From: Keith Busch <kbusch@kernel.org> > > The user can set the max_sectors limit to any valid value via sysfs > /sys/block/<dev>/queue/max_sectors_kb attribute. If the device limits > are ever rescanned, though, the limit reverts back to the kernel defined > BLK_DEF_MAX_SECTORS limit. > > Preserve the user's setting for the max_sectors limit as long as it's > valid. The user can reset back to defaults by writing 0 to the sysfs > file. > > Signed-off-by: Keith Busch <kbusch@kernel.org> > --- > block/blk-settings.c | 9 +++++++-- > block/blk-sysfs.c | 10 +++++++++- > include/linux/blkdev.h | 1 + > 3 files changed, 17 insertions(+), 3 deletions(-) > > diff --git a/block/blk-settings.c b/block/blk-settings.c > index 0477c4d527fee..e75304f853bd5 100644 > --- a/block/blk-settings.c > +++ b/block/blk-settings.c > @@ -40,7 +40,7 @@ void blk_set_default_limits(struct queue_limits *lim) > lim->virt_boundary_mask = 0; > lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; > lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; > - lim->max_dev_sectors = 0; > + lim->max_user_sectors = lim->max_dev_sectors = 0; > lim->chunk_sectors = 0; > lim->max_write_zeroes_sectors = 0; > lim->max_zone_append_sectors = 0; > @@ -135,7 +135,12 @@ void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_secto > limits->max_hw_sectors = max_hw_sectors; > > max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors); > - max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); > + > + if (limits->max_user_sectors) > + max_sectors = min_not_zero(max_sectors, limits->max_user_sectors); I don't think the min_not_zero here makes sense, as you just checked max_user_sectors for zero above, and max_sectors better not be zero. > + else > + max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); And please make BLK_DEF_MAX_SECTORS an unsigned constant as it should be and drop the min_t here. Instead of working around type mismatches just avoid them from the beginning.. > + if (max_sectors_kb == 0) { > + q->limits.max_user_sectors = 0; > + max_sectors_kb = min_t(unsigned int, max_hw_sectors_kb, > + BLK_DEF_MAX_SECTORS >> 1); .. which will also pay off here. > + } else if (max_sectors_kb > max_hw_sectors_kb || > + max_sectors_kb < page_kb) { > return -EINVAL; And this check should probably move above the old one to keep the sanity checks first. > + } else { > + q->limits.max_user_sectors = max_sectors_kb << 1; > + } i.e. if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) return -EINVAL; q->limits.max_user_sectors = max_sectors_kb << 1; /* reset to default when the user clears max_sectors_kb: */ if (max_sectors_kb == 0) { max_sectors_kb = min(max_hw_sectors_kb, BLK_DEF_MAX_SECTORS >> 1); }
On 12/23/22 02:52, Keith Busch wrote: > From: Keith Busch <kbusch@kernel.org> > > The user can set the max_sectors limit to any valid value via sysfs > /sys/block/<dev>/queue/max_sectors_kb attribute. If the device limits > are ever rescanned, though, the limit reverts back to the kernel defined > BLK_DEF_MAX_SECTORS limit. > > Preserve the user's setting for the max_sectors limit as long as it's > valid. The user can reset back to defaults by writing 0 to the sysfs > file. Updating Documentation/ABI/stable/sysfs-block about this change would be nice too. > > Signed-off-by: Keith Busch <kbusch@kernel.org> > --- > block/blk-settings.c | 9 +++++++-- > block/blk-sysfs.c | 10 +++++++++- > include/linux/blkdev.h | 1 + > 3 files changed, 17 insertions(+), 3 deletions(-) > > diff --git a/block/blk-settings.c b/block/blk-settings.c > index 0477c4d527fee..e75304f853bd5 100644 > --- a/block/blk-settings.c > +++ b/block/blk-settings.c > @@ -40,7 +40,7 @@ void blk_set_default_limits(struct queue_limits *lim) > lim->virt_boundary_mask = 0; > lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; > lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; > - lim->max_dev_sectors = 0; > + lim->max_user_sectors = lim->max_dev_sectors = 0; > lim->chunk_sectors = 0; > lim->max_write_zeroes_sectors = 0; > lim->max_zone_append_sectors = 0; > @@ -135,7 +135,12 @@ void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_secto > limits->max_hw_sectors = max_hw_sectors; > > max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors); > - max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); > + > + if (limits->max_user_sectors) > + max_sectors = min_not_zero(max_sectors, limits->max_user_sectors); > + else > + max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); > + > max_sectors = round_down(max_sectors, > limits->logical_block_size >> SECTOR_SHIFT); > limits->max_sectors = max_sectors; > diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c > index 93d9e9c9a6ea8..db5d1d908f5d9 100644 > --- a/block/blk-sysfs.c > +++ b/block/blk-sysfs.c > @@ -250,8 +250,16 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) > max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long) > q->limits.max_dev_sectors >> 1); > > - if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) > + if (max_sectors_kb == 0) { > + q->limits.max_user_sectors = 0; > + max_sectors_kb = min_t(unsigned int, max_hw_sectors_kb, > + BLK_DEF_MAX_SECTORS >> 1); > + } else if (max_sectors_kb > max_hw_sectors_kb || > + max_sectors_kb < page_kb) { > return -EINVAL; > + } else { > + q->limits.max_user_sectors = max_sectors_kb << 1; > + } > > spin_lock_irq(&q->queue_lock); > q->limits.max_sectors = max_sectors_kb << 1; > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h > index 301cf1cf4f2fa..71e97f0a87264 100644 > --- a/include/linux/blkdev.h > +++ b/include/linux/blkdev.h > @@ -288,6 +288,7 @@ struct queue_limits { > unsigned int max_dev_sectors; > unsigned int chunk_sectors; > unsigned int max_sectors; > + unsigned int max_user_sectors; > unsigned int max_segment_size; > unsigned int physical_block_size; > unsigned int logical_block_size;
On Fri, Dec 23, 2022 at 07:00:09AM +0100, Christoph Hellwig wrote: > On Thu, Dec 22, 2022 at 09:52:04AM -0800, Keith Busch wrote: > > + max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); > > And please make BLK_DEF_MAX_SECTORS an unsigned constant as it should be > and drop the min_t here. Instead of working around type mismatches > just avoid them from the beginning.. Let me just make sure I understand: you don't want BLK_DEF_MAX_SECTORS defined in an enum, and instead want it a 'const unsigned int'? Or #define? > > + } else if (max_sectors_kb > max_hw_sectors_kb || > > + max_sectors_kb < page_kb) { > > return -EINVAL; > > And this check should probably move above the old one to keep the > sanity checks first. > > > + } else { > > + q->limits.max_user_sectors = max_sectors_kb << 1; > > + } > > i.e. > > if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) > return -EINVAL; > > q->limits.max_user_sectors = max_sectors_kb << 1; > > /* reset to default when the user clears max_sectors_kb: */ > if (max_sectors_kb == 0) { We'll never reach here since 0 is < page_kb. But I think I can clean this up a little bit for the next version. > max_sectors_kb = > min(max_hw_sectors_kb, BLK_DEF_MAX_SECTORS >> 1); > }
On Tue, Dec 27, 2022 at 09:49:15AM -0700, Keith Busch wrote: > > and drop the min_t here. Instead of working around type mismatches > > just avoid them from the beginning.. > > Let me just make sure I understand: you don't want BLK_DEF_MAX_SECTORS > defined in an enum, and instead want it a 'const unsigned int'? Or > #define? Just make sure it's marked as unsigned, either and enum or define works, just make sure it has the u suffix. Note that for enums recent gccs enforce the same type over different embers, so you might have to split it from an existing catchall enum into a separate one.
diff --git a/block/blk-settings.c b/block/blk-settings.c index 0477c4d527fee..e75304f853bd5 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -40,7 +40,7 @@ void blk_set_default_limits(struct queue_limits *lim) lim->virt_boundary_mask = 0; lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; - lim->max_dev_sectors = 0; + lim->max_user_sectors = lim->max_dev_sectors = 0; lim->chunk_sectors = 0; lim->max_write_zeroes_sectors = 0; lim->max_zone_append_sectors = 0; @@ -135,7 +135,12 @@ void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_secto limits->max_hw_sectors = max_hw_sectors; max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors); - max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); + + if (limits->max_user_sectors) + max_sectors = min_not_zero(max_sectors, limits->max_user_sectors); + else + max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS); + max_sectors = round_down(max_sectors, limits->logical_block_size >> SECTOR_SHIFT); limits->max_sectors = max_sectors; diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 93d9e9c9a6ea8..db5d1d908f5d9 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -250,8 +250,16 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long) q->limits.max_dev_sectors >> 1); - if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) + if (max_sectors_kb == 0) { + q->limits.max_user_sectors = 0; + max_sectors_kb = min_t(unsigned int, max_hw_sectors_kb, + BLK_DEF_MAX_SECTORS >> 1); + } else if (max_sectors_kb > max_hw_sectors_kb || + max_sectors_kb < page_kb) { return -EINVAL; + } else { + q->limits.max_user_sectors = max_sectors_kb << 1; + } spin_lock_irq(&q->queue_lock); q->limits.max_sectors = max_sectors_kb << 1; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 301cf1cf4f2fa..71e97f0a87264 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -288,6 +288,7 @@ struct queue_limits { unsigned int max_dev_sectors; unsigned int chunk_sectors; unsigned int max_sectors; + unsigned int max_user_sectors; unsigned int max_segment_size; unsigned int physical_block_size; unsigned int logical_block_size;