| Message ID | 20190410074735.GA28842@kadam (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] dm zoned: Silence a static checker warning | expand |
On 2019/04/10 16:48, Dan Carpenter wrote: > My static checker complains about this line from dmz_get_zoned_device() > > aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1); > > The problem is that "aligned_capacity" and "dev->capacity" are sector_t > type (which is a u64) but blk_queue_zone_sectors(q) returns a u32 so the > higher 32 bits in "aligned_capacity" are always cleared to zero. This > patch adds a cast to u64 to address this issue. > > Fixes: 114e025968b5 ("dm zoned: ignore last smaller runt zone") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > v2: In v1 I changed blk_queue_zone_sectors() to return a sector_t type, > but in v2 I just add a cast. The v2 fix would end up going through > different maintainers and reviewers so the CC list has grown... > > Original discussion: https://marc.info/?l=kernel-janitors&m=155487663405737&w=2 > > drivers/md/dm-zoned-target.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c > index 8865c1709e16..b6cb44fa946d 100644 > --- a/drivers/md/dm-zoned-target.c > +++ b/drivers/md/dm-zoned-target.c > @@ -643,7 +643,8 @@ static int dmz_get_zoned_device(struct dm_target *ti, char *path) > > q = bdev_get_queue(dev->bdev); > dev->capacity = i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; > - aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1); > + aligned_capacity = dev->capacity & > + ~((u64)blk_queue_zone_sectors(q) - 1); sector_t is an u64 only if CONFIG_LBDAF is defined (I think this option is going away though). Otherwise it is an unsigned long which would be u32 on 32 bits arch. Not a problem in terms of arithmetic, but why not cast to sector_t directly ? > if (ti->begin || > ((ti->len != dev->capacity) && (ti->len != aligned_capacity))) { > ti->error = "Partial mapping not supported"; >
On Wed, Apr 10, 2019 at 07:56:14AM +0000, Damien Le Moal wrote: > On 2019/04/10 16:48, Dan Carpenter wrote: > > My static checker complains about this line from dmz_get_zoned_device() > > > > aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1); > > > > The problem is that "aligned_capacity" and "dev->capacity" are sector_t > > type (which is a u64) but blk_queue_zone_sectors(q) returns a u32 so the > > higher 32 bits in "aligned_capacity" are always cleared to zero. This > > patch adds a cast to u64 to address this issue. > > > > Fixes: 114e025968b5 ("dm zoned: ignore last smaller runt zone") > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > --- > > v2: In v1 I changed blk_queue_zone_sectors() to return a sector_t type, > > but in v2 I just add a cast. The v2 fix would end up going through > > different maintainers and reviewers so the CC list has grown... > > > > Original discussion: https://marc.info/?l=kernel-janitors&m=155487663405737&w=2 > > > > drivers/md/dm-zoned-target.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c > > index 8865c1709e16..b6cb44fa946d 100644 > > --- a/drivers/md/dm-zoned-target.c > > +++ b/drivers/md/dm-zoned-target.c > > @@ -643,7 +643,8 @@ static int dmz_get_zoned_device(struct dm_target *ti, char *path) > > > > q = bdev_get_queue(dev->bdev); > > dev->capacity = i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; > > - aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1); > > + aligned_capacity = dev->capacity & > > + ~((u64)blk_queue_zone_sectors(q) - 1); > > sector_t is an u64 only if CONFIG_LBDAF is defined (I think this option is going > away though). Otherwise it is an unsigned long which would be u32 on 32 bits > arch. Not a problem in terms of arithmetic, but why not cast to sector_t directly ? > I would have prefered to do that but I didn't have strong feelings either way. I am always slight annoyed when people don't just copy and paste my code when I tell them how to fix a patch so I decided to go with your version... :P regards, dan carpenter
On 2019/04/10 17:03, Dan Carpenter wrote: > On Wed, Apr 10, 2019 at 07:56:14AM +0000, Damien Le Moal wrote: >> On 2019/04/10 16:48, Dan Carpenter wrote: >>> My static checker complains about this line from dmz_get_zoned_device() >>> >>> aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1); >>> >>> The problem is that "aligned_capacity" and "dev->capacity" are sector_t >>> type (which is a u64) but blk_queue_zone_sectors(q) returns a u32 so the >>> higher 32 bits in "aligned_capacity" are always cleared to zero. This >>> patch adds a cast to u64 to address this issue. >>> >>> Fixes: 114e025968b5 ("dm zoned: ignore last smaller runt zone") >>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> >>> --- >>> v2: In v1 I changed blk_queue_zone_sectors() to return a sector_t type, >>> but in v2 I just add a cast. The v2 fix would end up going through >>> different maintainers and reviewers so the CC list has grown... >>> >>> Original discussion: https://marc.info/?l=kernel-janitors&m=155487663405737&w=2 >>> >>> drivers/md/dm-zoned-target.c | 3 ++- >>> 1 file changed, 2 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c >>> index 8865c1709e16..b6cb44fa946d 100644 >>> --- a/drivers/md/dm-zoned-target.c >>> +++ b/drivers/md/dm-zoned-target.c >>> @@ -643,7 +643,8 @@ static int dmz_get_zoned_device(struct dm_target *ti, char *path) >>> >>> q = bdev_get_queue(dev->bdev); >>> dev->capacity = i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; >>> - aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1); >>> + aligned_capacity = dev->capacity & >>> + ~((u64)blk_queue_zone_sectors(q) - 1); >> >> sector_t is an u64 only if CONFIG_LBDAF is defined (I think this option is going >> away though). Otherwise it is an unsigned long which would be u32 on 32 bits >> arch. Not a problem in terms of arithmetic, but why not cast to sector_t directly ? >> > > I would have prefered to do that but I didn't have strong feelings > either way. I am always slight annoyed when people don't just copy and > paste my code when I tell them how to fix a patch so I decided to go > with your version... :P I proposed u64 cast without checking sector_t definition. After doing that, I liked your sector_t cast more than my own misinformed proposal :)
diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c index 8865c1709e16..b6cb44fa946d 100644 --- a/drivers/md/dm-zoned-target.c +++ b/drivers/md/dm-zoned-target.c @@ -643,7 +643,8 @@ static int dmz_get_zoned_device(struct dm_target *ti, char *path) q = bdev_get_queue(dev->bdev); dev->capacity = i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT; - aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1); + aligned_capacity = dev->capacity & + ~((u64)blk_queue_zone_sectors(q) - 1); if (ti->begin || ((ti->len != dev->capacity) && (ti->len != aligned_capacity))) { ti->error = "Partial mapping not supported";
My static checker complains about this line from dmz_get_zoned_device() aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1); The problem is that "aligned_capacity" and "dev->capacity" are sector_t type (which is a u64) but blk_queue_zone_sectors(q) returns a u32 so the higher 32 bits in "aligned_capacity" are always cleared to zero. This patch adds a cast to u64 to address this issue. Fixes: 114e025968b5 ("dm zoned: ignore last smaller runt zone") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- v2: In v1 I changed blk_queue_zone_sectors() to return a sector_t type, but in v2 I just add a cast. The v2 fix would end up going through different maintainers and reviewers so the CC list has grown... Original discussion: https://marc.info/?l=kernel-janitors&m=155487663405737&w=2 drivers/md/dm-zoned-target.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)