* fix a dax/block device attribute registration regression
@ 2021-09-22 18:33 Christoph Hellwig
2021-09-22 18:33 ` [PATCH 1/3] nvdimm/pmem: fix creating the dax group Christoph Hellwig
` (3 more replies)
0 siblings, 4 replies; 13+ messages in thread
From: Christoph Hellwig @ 2021-09-22 18:33 UTC (permalink / raw)
To: Dan Williams, Jens Axboe
Cc: Vishal Verma, Dave Jiang, Ira Weiny, linux-block, nvdimm
Hi Dan and Jens,
this series fixed a regression in how the dax/write_cache attribute of the
pmem devices was registere. It does so by both fixing the API abuse in the
driver and (temporarily) the behavior change in the block layer that made
this API abuse not work anymore.
Diffstat:
block/genhd.c | 3 +-
drivers/dax/super.c | 64 --------------------------------------------------
drivers/nvdimm/pmem.c | 48 ++++++++++++++++++++++++++++++++++---
include/linux/dax.h | 2 -
4 files changed, 46 insertions(+), 71 deletions(-)
^ permalink raw reply [flat|nested] 13+ messages in thread* [PATCH 1/3] nvdimm/pmem: fix creating the dax group 2021-09-22 18:33 fix a dax/block device attribute registration regression Christoph Hellwig @ 2021-09-22 18:33 ` Christoph Hellwig 2021-09-22 18:33 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig ` (2 subsequent siblings) 3 siblings, 0 replies; 13+ messages in thread From: Christoph Hellwig @ 2021-09-22 18:33 UTC (permalink / raw) To: Dan Williams, Jens Axboe Cc: Vishal Verma, Dave Jiang, Ira Weiny, linux-block, nvdimm The recent block layer refactoring broke the way how the pmem driver abused device_add_disk. Fix this by properly passing the attribute groups to device_add_disk. Fixes: 52b85909f85d ("block: fold register_disk into device_add_disk") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> --- drivers/nvdimm/pmem.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 72de88ff0d30d..ef4950f808326 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -380,7 +380,6 @@ static int pmem_attach_disk(struct device *dev, struct nd_pfn_sb *pfn_sb; struct pmem_device *pmem; struct request_queue *q; - struct device *gendev; struct gendisk *disk; void *addr; int rc; @@ -489,10 +488,8 @@ static int pmem_attach_disk(struct device *dev, } dax_write_cache(dax_dev, nvdimm_has_cache(nd_region)); pmem->dax_dev = dax_dev; - gendev = disk_to_dev(disk); - gendev->groups = pmem_attribute_groups; - device_add_disk(dev, disk, NULL); + device_add_disk(dev, disk, pmem_attribute_groups); if (devm_add_action_or_reset(dev, pmem_release_disk, pmem)) return -ENOMEM; -- 2.30.2 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem 2021-09-22 18:33 fix a dax/block device attribute registration regression Christoph Hellwig 2021-09-22 18:33 ` [PATCH 1/3] nvdimm/pmem: fix creating the dax group Christoph Hellwig @ 2021-09-22 18:33 ` Christoph Hellwig 2021-09-22 21:40 ` Ira Weiny 2021-09-22 18:33 ` [PATCH 3/3] block: warn if ->groups is set when calling add_disk Christoph Hellwig 2021-09-27 18:19 ` fix a dax/block device attribute registration regression Dan Williams 3 siblings, 1 reply; 13+ messages in thread From: Christoph Hellwig @ 2021-09-22 18:33 UTC (permalink / raw) To: Dan Williams, Jens Axboe Cc: Vishal Verma, Dave Jiang, Ira Weiny, linux-block, nvdimm dax_attribute_group is only used by the pmem driver, and can avoid the completely pointless lookup by the disk name if moved there. This leaves just a single caller of dax_get_by_host, so move dax_get_by_host into the same ifdef block as that caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> --- drivers/dax/super.c | 100 ++++++++---------------------------------- drivers/nvdimm/pmem.c | 43 ++++++++++++++++++ include/linux/dax.h | 2 - 3 files changed, 61 insertions(+), 84 deletions(-) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index fc89e91beea7c..b882cf8106ea3 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -63,6 +63,24 @@ static int dax_host_hash(const char *host) return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE; } +#ifdef CONFIG_BLOCK +#include <linux/blkdev.h> + +int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, + pgoff_t *pgoff) +{ + sector_t start_sect = bdev ? get_start_sect(bdev) : 0; + phys_addr_t phys_off = (start_sect + sector) * 512; + + if (pgoff) + *pgoff = PHYS_PFN(phys_off); + if (phys_off % PAGE_SIZE || size % PAGE_SIZE) + return -EINVAL; + return 0; +} +EXPORT_SYMBOL(bdev_dax_pgoff); + +#if IS_ENABLED(CONFIG_FS_DAX) /** * dax_get_by_host() - temporary lookup mechanism for filesystem-dax * @host: alternate name for the device registered by a dax driver @@ -94,24 +112,6 @@ static struct dax_device *dax_get_by_host(const char *host) return found; } -#ifdef CONFIG_BLOCK -#include <linux/blkdev.h> - -int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, - pgoff_t *pgoff) -{ - sector_t start_sect = bdev ? get_start_sect(bdev) : 0; - phys_addr_t phys_off = (start_sect + sector) * 512; - - if (pgoff) - *pgoff = PHYS_PFN(phys_off); - if (phys_off % PAGE_SIZE || size % PAGE_SIZE) - return -EINVAL; - return 0; -} -EXPORT_SYMBOL(bdev_dax_pgoff); - -#if IS_ENABLED(CONFIG_FS_DAX) struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) { if (!blk_queue_dax(bdev->bd_disk->queue)) @@ -231,70 +231,6 @@ enum dax_device_flags { DAXDEV_SYNC, }; -static ssize_t write_cache_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); - ssize_t rc; - - WARN_ON_ONCE(!dax_dev); - if (!dax_dev) - return -ENXIO; - - rc = sprintf(buf, "%d\n", !!dax_write_cache_enabled(dax_dev)); - put_dax(dax_dev); - return rc; -} - -static ssize_t write_cache_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) -{ - bool write_cache; - int rc = strtobool(buf, &write_cache); - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); - - WARN_ON_ONCE(!dax_dev); - if (!dax_dev) - return -ENXIO; - - if (rc) - len = rc; - else - dax_write_cache(dax_dev, write_cache); - - put_dax(dax_dev); - return len; -} -static DEVICE_ATTR_RW(write_cache); - -static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) -{ - struct device *dev = container_of(kobj, typeof(*dev), kobj); - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); - - WARN_ON_ONCE(!dax_dev); - if (!dax_dev) - return 0; - -#ifndef CONFIG_ARCH_HAS_PMEM_API - if (a == &dev_attr_write_cache.attr) - return 0; -#endif - return a->mode; -} - -static struct attribute *dax_attributes[] = { - &dev_attr_write_cache.attr, - NULL, -}; - -struct attribute_group dax_attribute_group = { - .name = "dax", - .attrs = dax_attributes, - .is_visible = dax_visible, -}; -EXPORT_SYMBOL_GPL(dax_attribute_group); - /** * dax_direct_access() - translate a device pgoff to an absolute pfn * @dax_dev: a dax_device instance representing the logical memory range diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index ef4950f808326..bbeb3f46db157 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -328,6 +328,49 @@ static const struct dax_operations pmem_dax_ops = { .zero_page_range = pmem_dax_zero_page_range, }; +static ssize_t write_cache_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pmem_device *pmem = dev_to_disk(dev)->private_data; + + return sprintf(buf, "%d\n", !!dax_write_cache_enabled(pmem->dax_dev)); +} + +static ssize_t write_cache_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + struct pmem_device *pmem = dev_to_disk(dev)->private_data; + bool write_cache; + int rc; + + rc = strtobool(buf, &write_cache); + if (rc) + return rc; + dax_write_cache(pmem->dax_dev, write_cache); + return len; +} +static DEVICE_ATTR_RW(write_cache); + +static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) +{ +#ifndef CONFIG_ARCH_HAS_PMEM_API + if (a == &dev_attr_write_cache.attr) + return 0; +#endif + return a->mode; +} + +static struct attribute *dax_attributes[] = { + &dev_attr_write_cache.attr, + NULL, +}; + +static const struct attribute_group dax_attribute_group = { + .name = "dax", + .attrs = dax_attributes, + .is_visible = dax_visible, +}; + static const struct attribute_group *pmem_attribute_groups[] = { &dax_attribute_group, NULL, diff --git a/include/linux/dax.h b/include/linux/dax.h index 2619d94c308d4..8623caa673889 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -38,8 +38,6 @@ struct dax_operations { int (*zero_page_range)(struct dax_device *, pgoff_t, size_t); }; -extern struct attribute_group dax_attribute_group; - #if IS_ENABLED(CONFIG_DAX) struct dax_device *alloc_dax(void *private, const char *host, const struct dax_operations *ops, unsigned long flags); -- 2.30.2 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem 2021-09-22 18:33 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig @ 2021-09-22 21:40 ` Ira Weiny 0 siblings, 0 replies; 13+ messages in thread From: Ira Weiny @ 2021-09-22 21:40 UTC (permalink / raw) To: Christoph Hellwig Cc: Dan Williams, Jens Axboe, Vishal Verma, Dave Jiang, linux-block, nvdimm On Wed, Sep 22, 2021 at 08:33:30PM +0200, Christoph Hellwig wrote: > dax_attribute_group is only used by the pmem driver, and can avoid the > completely pointless lookup by the disk name if moved there. This > leaves just a single caller of dax_get_by_host, so move dax_get_by_host > into the same ifdef block as that caller. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> > --- > drivers/dax/super.c | 100 ++++++++---------------------------------- > drivers/nvdimm/pmem.c | 43 ++++++++++++++++++ > include/linux/dax.h | 2 - > 3 files changed, 61 insertions(+), 84 deletions(-) > > diff --git a/drivers/dax/super.c b/drivers/dax/super.c > index fc89e91beea7c..b882cf8106ea3 100644 > --- a/drivers/dax/super.c > +++ b/drivers/dax/super.c > @@ -63,6 +63,24 @@ static int dax_host_hash(const char *host) > return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE; > } > > +#ifdef CONFIG_BLOCK > +#include <linux/blkdev.h> > + > +int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, > + pgoff_t *pgoff) > +{ > + sector_t start_sect = bdev ? get_start_sect(bdev) : 0; > + phys_addr_t phys_off = (start_sect + sector) * 512; > + > + if (pgoff) > + *pgoff = PHYS_PFN(phys_off); > + if (phys_off % PAGE_SIZE || size % PAGE_SIZE) > + return -EINVAL; > + return 0; > +} > +EXPORT_SYMBOL(bdev_dax_pgoff); > + > +#if IS_ENABLED(CONFIG_FS_DAX) > /** > * dax_get_by_host() - temporary lookup mechanism for filesystem-dax > * @host: alternate name for the device registered by a dax driver > @@ -94,24 +112,6 @@ static struct dax_device *dax_get_by_host(const char *host) > return found; > } > > -#ifdef CONFIG_BLOCK > -#include <linux/blkdev.h> > - > -int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, > - pgoff_t *pgoff) > -{ > - sector_t start_sect = bdev ? get_start_sect(bdev) : 0; > - phys_addr_t phys_off = (start_sect + sector) * 512; > - > - if (pgoff) > - *pgoff = PHYS_PFN(phys_off); > - if (phys_off % PAGE_SIZE || size % PAGE_SIZE) > - return -EINVAL; > - return 0; > -} > -EXPORT_SYMBOL(bdev_dax_pgoff); > - > -#if IS_ENABLED(CONFIG_FS_DAX) > struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) > { > if (!blk_queue_dax(bdev->bd_disk->queue)) > @@ -231,70 +231,6 @@ enum dax_device_flags { > DAXDEV_SYNC, > }; > > -static ssize_t write_cache_show(struct device *dev, > - struct device_attribute *attr, char *buf) > -{ > - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); > - ssize_t rc; > - > - WARN_ON_ONCE(!dax_dev); > - if (!dax_dev) > - return -ENXIO; > - > - rc = sprintf(buf, "%d\n", !!dax_write_cache_enabled(dax_dev)); > - put_dax(dax_dev); > - return rc; > -} > - > -static ssize_t write_cache_store(struct device *dev, > - struct device_attribute *attr, const char *buf, size_t len) > -{ > - bool write_cache; > - int rc = strtobool(buf, &write_cache); > - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); > - > - WARN_ON_ONCE(!dax_dev); > - if (!dax_dev) > - return -ENXIO; > - > - if (rc) > - len = rc; > - else > - dax_write_cache(dax_dev, write_cache); > - > - put_dax(dax_dev); > - return len; > -} > -static DEVICE_ATTR_RW(write_cache); > - > -static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) > -{ > - struct device *dev = container_of(kobj, typeof(*dev), kobj); > - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); > - > - WARN_ON_ONCE(!dax_dev); > - if (!dax_dev) > - return 0; > - > -#ifndef CONFIG_ARCH_HAS_PMEM_API > - if (a == &dev_attr_write_cache.attr) > - return 0; > -#endif > - return a->mode; > -} > - > -static struct attribute *dax_attributes[] = { > - &dev_attr_write_cache.attr, > - NULL, > -}; > - > -struct attribute_group dax_attribute_group = { > - .name = "dax", > - .attrs = dax_attributes, > - .is_visible = dax_visible, > -}; > -EXPORT_SYMBOL_GPL(dax_attribute_group); > - > /** > * dax_direct_access() - translate a device pgoff to an absolute pfn > * @dax_dev: a dax_device instance representing the logical memory range > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c > index ef4950f808326..bbeb3f46db157 100644 > --- a/drivers/nvdimm/pmem.c > +++ b/drivers/nvdimm/pmem.c > @@ -328,6 +328,49 @@ static const struct dax_operations pmem_dax_ops = { > .zero_page_range = pmem_dax_zero_page_range, > }; > > +static ssize_t write_cache_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct pmem_device *pmem = dev_to_disk(dev)->private_data; > + > + return sprintf(buf, "%d\n", !!dax_write_cache_enabled(pmem->dax_dev)); > +} > + > +static ssize_t write_cache_store(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t len) > +{ > + struct pmem_device *pmem = dev_to_disk(dev)->private_data; > + bool write_cache; > + int rc; > + > + rc = strtobool(buf, &write_cache); > + if (rc) > + return rc; > + dax_write_cache(pmem->dax_dev, write_cache); > + return len; > +} > +static DEVICE_ATTR_RW(write_cache); > + > +static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) > +{ > +#ifndef CONFIG_ARCH_HAS_PMEM_API > + if (a == &dev_attr_write_cache.attr) > + return 0; > +#endif > + return a->mode; > +} > + > +static struct attribute *dax_attributes[] = { > + &dev_attr_write_cache.attr, > + NULL, > +}; > + > +static const struct attribute_group dax_attribute_group = { > + .name = "dax", > + .attrs = dax_attributes, > + .is_visible = dax_visible, > +}; > + > static const struct attribute_group *pmem_attribute_groups[] = { > &dax_attribute_group, > NULL, > diff --git a/include/linux/dax.h b/include/linux/dax.h > index 2619d94c308d4..8623caa673889 100644 > --- a/include/linux/dax.h > +++ b/include/linux/dax.h > @@ -38,8 +38,6 @@ struct dax_operations { > int (*zero_page_range)(struct dax_device *, pgoff_t, size_t); > }; > > -extern struct attribute_group dax_attribute_group; > - > #if IS_ENABLED(CONFIG_DAX) > struct dax_device *alloc_dax(void *private, const char *host, > const struct dax_operations *ops, unsigned long flags); > -- > 2.30.2 > > ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH 3/3] block: warn if ->groups is set when calling add_disk 2021-09-22 18:33 fix a dax/block device attribute registration regression Christoph Hellwig 2021-09-22 18:33 ` [PATCH 1/3] nvdimm/pmem: fix creating the dax group Christoph Hellwig 2021-09-22 18:33 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig @ 2021-09-22 18:33 ` Christoph Hellwig 2021-09-27 18:19 ` fix a dax/block device attribute registration regression Dan Williams 3 siblings, 0 replies; 13+ messages in thread From: Christoph Hellwig @ 2021-09-22 18:33 UTC (permalink / raw) To: Dan Williams, Jens Axboe Cc: Vishal Verma, Dave Jiang, Ira Weiny, linux-block, nvdimm The proper API is to pass the groups to device_add_disk, but the code used to also allow groups being set before calling *add_disk. Warn about that but keep the group pointer intact for now so that it can be removed again after a grace period. Fixes: 52b85909f85d ("block: fold register_disk into device_add_disk") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> --- block/genhd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/genhd.c b/block/genhd.c index 7b6e5e1cf9564..409cf608cc5bd 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -439,7 +439,8 @@ int device_add_disk(struct device *parent, struct gendisk *disk, dev_set_uevent_suppress(ddev, 1); ddev->parent = parent; - ddev->groups = groups; + if (!WARN_ON_ONCE(ddev->groups)) + ddev->groups = groups; dev_set_name(ddev, "%s", disk->disk_name); if (!(disk->flags & GENHD_FL_HIDDEN)) ddev->devt = MKDEV(disk->major, disk->first_minor); -- 2.30.2 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: fix a dax/block device attribute registration regression 2021-09-22 18:33 fix a dax/block device attribute registration regression Christoph Hellwig ` (2 preceding siblings ...) 2021-09-22 18:33 ` [PATCH 3/3] block: warn if ->groups is set when calling add_disk Christoph Hellwig @ 2021-09-27 18:19 ` Dan Williams 3 siblings, 0 replies; 13+ messages in thread From: Dan Williams @ 2021-09-27 18:19 UTC (permalink / raw) To: Christoph Hellwig Cc: Jens Axboe, Vishal Verma, Dave Jiang, Ira Weiny, linux-block, Linux NVDIMM On Wed, Sep 22, 2021 at 11:34 AM Christoph Hellwig <hch@lst.de> wrote: > > Hi Dan and Jens, > > this series fixed a regression in how the dax/write_cache attribute of the > pmem devices was registere. It does so by both fixing the API abuse in the > driver and (temporarily) the behavior change in the block layer that made > this API abuse not work anymore. I took patch1 into for-5.15/libnvdimm, patch2 into for-5.16/libnvdimm, and I'll leave patch3 for Jens. ^ permalink raw reply [flat|nested] 13+ messages in thread
* dax_supported() related cleanups v2 @ 2021-09-22 17:34 Christoph Hellwig 2021-09-22 17:34 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig 0 siblings, 1 reply; 13+ messages in thread From: Christoph Hellwig @ 2021-09-22 17:34 UTC (permalink / raw) To: Dan Williams, Vishal Verma, Dave Jiang Cc: Mike Snitzer, Matthew Wilcox, linux-xfs, nvdimm, linux-fsdevel, linux-ext4 Hi all, this series first clarifies how to use fsdax in the Kconfig help a bit, and then untangles the code path that checks if fsdax is supported. Changes since v1: - improve the FS_DAX Kconfig help text further - write a proper commit log for a patch missing it Diffstat drivers/dax/super.c | 191 +++++++++++++++++++------------------------------- drivers/md/dm-table.c | 9 -- drivers/md/dm.c | 2 fs/Kconfig | 21 ++++- fs/ext2/super.c | 3 fs/ext4/super.c | 3 fs/xfs/xfs_super.c | 16 +++- include/linux/dax.h | 41 +--------- 8 files changed, 117 insertions(+), 169 deletions(-) ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem 2021-09-22 17:34 dax_supported() related cleanups v2 Christoph Hellwig @ 2021-09-22 17:34 ` Christoph Hellwig 0 siblings, 0 replies; 13+ messages in thread From: Christoph Hellwig @ 2021-09-22 17:34 UTC (permalink / raw) To: Dan Williams, Vishal Verma, Dave Jiang Cc: Mike Snitzer, Matthew Wilcox, linux-xfs, nvdimm, linux-fsdevel, linux-ext4 dax_attribute_group is only used by the pmem driver, and can avoid the completely pointless lookup by the disk name if moved there. This leaves just a single caller of dax_get_by_host, so move dax_get_by_host into the same ifdef block as that caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> --- drivers/dax/super.c | 100 ++++++++---------------------------------- drivers/nvdimm/pmem.c | 43 ++++++++++++++++++ include/linux/dax.h | 2 - 3 files changed, 61 insertions(+), 84 deletions(-) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index fc89e91beea7c..b882cf8106ea3 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -63,6 +63,24 @@ static int dax_host_hash(const char *host) return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE; } +#ifdef CONFIG_BLOCK +#include <linux/blkdev.h> + +int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, + pgoff_t *pgoff) +{ + sector_t start_sect = bdev ? get_start_sect(bdev) : 0; + phys_addr_t phys_off = (start_sect + sector) * 512; + + if (pgoff) + *pgoff = PHYS_PFN(phys_off); + if (phys_off % PAGE_SIZE || size % PAGE_SIZE) + return -EINVAL; + return 0; +} +EXPORT_SYMBOL(bdev_dax_pgoff); + +#if IS_ENABLED(CONFIG_FS_DAX) /** * dax_get_by_host() - temporary lookup mechanism for filesystem-dax * @host: alternate name for the device registered by a dax driver @@ -94,24 +112,6 @@ static struct dax_device *dax_get_by_host(const char *host) return found; } -#ifdef CONFIG_BLOCK -#include <linux/blkdev.h> - -int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, - pgoff_t *pgoff) -{ - sector_t start_sect = bdev ? get_start_sect(bdev) : 0; - phys_addr_t phys_off = (start_sect + sector) * 512; - - if (pgoff) - *pgoff = PHYS_PFN(phys_off); - if (phys_off % PAGE_SIZE || size % PAGE_SIZE) - return -EINVAL; - return 0; -} -EXPORT_SYMBOL(bdev_dax_pgoff); - -#if IS_ENABLED(CONFIG_FS_DAX) struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) { if (!blk_queue_dax(bdev->bd_disk->queue)) @@ -231,70 +231,6 @@ enum dax_device_flags { DAXDEV_SYNC, }; -static ssize_t write_cache_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); - ssize_t rc; - - WARN_ON_ONCE(!dax_dev); - if (!dax_dev) - return -ENXIO; - - rc = sprintf(buf, "%d\n", !!dax_write_cache_enabled(dax_dev)); - put_dax(dax_dev); - return rc; -} - -static ssize_t write_cache_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) -{ - bool write_cache; - int rc = strtobool(buf, &write_cache); - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); - - WARN_ON_ONCE(!dax_dev); - if (!dax_dev) - return -ENXIO; - - if (rc) - len = rc; - else - dax_write_cache(dax_dev, write_cache); - - put_dax(dax_dev); - return len; -} -static DEVICE_ATTR_RW(write_cache); - -static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) -{ - struct device *dev = container_of(kobj, typeof(*dev), kobj); - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); - - WARN_ON_ONCE(!dax_dev); - if (!dax_dev) - return 0; - -#ifndef CONFIG_ARCH_HAS_PMEM_API - if (a == &dev_attr_write_cache.attr) - return 0; -#endif - return a->mode; -} - -static struct attribute *dax_attributes[] = { - &dev_attr_write_cache.attr, - NULL, -}; - -struct attribute_group dax_attribute_group = { - .name = "dax", - .attrs = dax_attributes, - .is_visible = dax_visible, -}; -EXPORT_SYMBOL_GPL(dax_attribute_group); - /** * dax_direct_access() - translate a device pgoff to an absolute pfn * @dax_dev: a dax_device instance representing the logical memory range diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index ef4950f808326..bbeb3f46db157 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -328,6 +328,49 @@ static const struct dax_operations pmem_dax_ops = { .zero_page_range = pmem_dax_zero_page_range, }; +static ssize_t write_cache_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pmem_device *pmem = dev_to_disk(dev)->private_data; + + return sprintf(buf, "%d\n", !!dax_write_cache_enabled(pmem->dax_dev)); +} + +static ssize_t write_cache_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + struct pmem_device *pmem = dev_to_disk(dev)->private_data; + bool write_cache; + int rc; + + rc = strtobool(buf, &write_cache); + if (rc) + return rc; + dax_write_cache(pmem->dax_dev, write_cache); + return len; +} +static DEVICE_ATTR_RW(write_cache); + +static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) +{ +#ifndef CONFIG_ARCH_HAS_PMEM_API + if (a == &dev_attr_write_cache.attr) + return 0; +#endif + return a->mode; +} + +static struct attribute *dax_attributes[] = { + &dev_attr_write_cache.attr, + NULL, +}; + +static const struct attribute_group dax_attribute_group = { + .name = "dax", + .attrs = dax_attributes, + .is_visible = dax_visible, +}; + static const struct attribute_group *pmem_attribute_groups[] = { &dax_attribute_group, NULL, diff --git a/include/linux/dax.h b/include/linux/dax.h index 2619d94c308d4..8623caa673889 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -38,8 +38,6 @@ struct dax_operations { int (*zero_page_range)(struct dax_device *, pgoff_t, size_t); }; -extern struct attribute_group dax_attribute_group; - #if IS_ENABLED(CONFIG_DAX) struct dax_device *alloc_dax(void *private, const char *host, const struct dax_operations *ops, unsigned long flags); -- 2.30.2 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* fix a dax/block device attribute registration regression @ 2021-09-20 7:27 Christoph Hellwig 2021-09-20 7:27 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig 0 siblings, 1 reply; 13+ messages in thread From: Christoph Hellwig @ 2021-09-20 7:27 UTC (permalink / raw) To: Dan Williams, Jens Axboe Cc: Vishal Verma, Dave Jiang, Ira Weiny, linux-block, nvdimm Hi Dan and Jens, this series fixed a regression in how the dax/write_cache attribute of the pmem devices was registere. It does so by both fixing the API abuse in the driver and (temporarily) the behavior change in the block layer that made this API abuse not work anymore. Diffstat: block/genhd.c | 3 +- drivers/dax/super.c | 64 -------------------------------------------------- drivers/nvdimm/pmem.c | 48 ++++++++++++++++++++++++++++++++++--- include/linux/dax.h | 2 - 4 files changed, 46 insertions(+), 71 deletions(-) ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem 2021-09-20 7:27 fix a dax/block device attribute registration regression Christoph Hellwig @ 2021-09-20 7:27 ` Christoph Hellwig 2021-09-20 18:00 ` kernel test robot ` (2 more replies) 0 siblings, 3 replies; 13+ messages in thread From: Christoph Hellwig @ 2021-09-20 7:27 UTC (permalink / raw) To: Dan Williams, Jens Axboe Cc: Vishal Verma, Dave Jiang, Ira Weiny, linux-block, nvdimm dax_attribute_group is only used by the pmem driver, and can avoid the completely pointless lookup by the disk name if moved there. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/dax/super.c | 64 ------------------------------------------- drivers/nvdimm/pmem.c | 43 +++++++++++++++++++++++++++++ include/linux/dax.h | 2 -- 3 files changed, 43 insertions(+), 66 deletions(-) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index fc89e91beea7c..e03d94bdc0449 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -231,70 +231,6 @@ enum dax_device_flags { DAXDEV_SYNC, }; -static ssize_t write_cache_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); - ssize_t rc; - - WARN_ON_ONCE(!dax_dev); - if (!dax_dev) - return -ENXIO; - - rc = sprintf(buf, "%d\n", !!dax_write_cache_enabled(dax_dev)); - put_dax(dax_dev); - return rc; -} - -static ssize_t write_cache_store(struct device *dev, - struct device_attribute *attr, const char *buf, size_t len) -{ - bool write_cache; - int rc = strtobool(buf, &write_cache); - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); - - WARN_ON_ONCE(!dax_dev); - if (!dax_dev) - return -ENXIO; - - if (rc) - len = rc; - else - dax_write_cache(dax_dev, write_cache); - - put_dax(dax_dev); - return len; -} -static DEVICE_ATTR_RW(write_cache); - -static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) -{ - struct device *dev = container_of(kobj, typeof(*dev), kobj); - struct dax_device *dax_dev = dax_get_by_host(dev_name(dev)); - - WARN_ON_ONCE(!dax_dev); - if (!dax_dev) - return 0; - -#ifndef CONFIG_ARCH_HAS_PMEM_API - if (a == &dev_attr_write_cache.attr) - return 0; -#endif - return a->mode; -} - -static struct attribute *dax_attributes[] = { - &dev_attr_write_cache.attr, - NULL, -}; - -struct attribute_group dax_attribute_group = { - .name = "dax", - .attrs = dax_attributes, - .is_visible = dax_visible, -}; -EXPORT_SYMBOL_GPL(dax_attribute_group); - /** * dax_direct_access() - translate a device pgoff to an absolute pfn * @dax_dev: a dax_device instance representing the logical memory range diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index ef4950f808326..bbeb3f46db157 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -328,6 +328,49 @@ static const struct dax_operations pmem_dax_ops = { .zero_page_range = pmem_dax_zero_page_range, }; +static ssize_t write_cache_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pmem_device *pmem = dev_to_disk(dev)->private_data; + + return sprintf(buf, "%d\n", !!dax_write_cache_enabled(pmem->dax_dev)); +} + +static ssize_t write_cache_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + struct pmem_device *pmem = dev_to_disk(dev)->private_data; + bool write_cache; + int rc; + + rc = strtobool(buf, &write_cache); + if (rc) + return rc; + dax_write_cache(pmem->dax_dev, write_cache); + return len; +} +static DEVICE_ATTR_RW(write_cache); + +static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n) +{ +#ifndef CONFIG_ARCH_HAS_PMEM_API + if (a == &dev_attr_write_cache.attr) + return 0; +#endif + return a->mode; +} + +static struct attribute *dax_attributes[] = { + &dev_attr_write_cache.attr, + NULL, +}; + +static const struct attribute_group dax_attribute_group = { + .name = "dax", + .attrs = dax_attributes, + .is_visible = dax_visible, +}; + static const struct attribute_group *pmem_attribute_groups[] = { &dax_attribute_group, NULL, diff --git a/include/linux/dax.h b/include/linux/dax.h index 2619d94c308d4..8623caa673889 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -38,8 +38,6 @@ struct dax_operations { int (*zero_page_range)(struct dax_device *, pgoff_t, size_t); }; -extern struct attribute_group dax_attribute_group; - #if IS_ENABLED(CONFIG_DAX) struct dax_device *alloc_dax(void *private, const char *host, const struct dax_operations *ops, unsigned long flags); -- 2.30.2 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem 2021-09-20 7:27 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig @ 2021-09-20 18:00 ` kernel test robot 2021-09-20 23:29 ` Dan Williams 2021-09-20 22:51 ` Ira Weiny 2021-09-20 23:37 ` Dan Williams 2 siblings, 1 reply; 13+ messages in thread From: kernel test robot @ 2021-09-20 18:00 UTC (permalink / raw) To: Christoph Hellwig, Dan Williams, Jens Axboe Cc: kbuild-all, Vishal Verma, Dave Jiang, Ira Weiny, linux-block, nvdimm [-- Attachment #1: Type: text/plain, Size: 4375 bytes --] Hi Christoph, I love your patch! Yet something to improve: [auto build test ERROR on axboe-block/for-next] [also build test ERROR on linus/master v5.15-rc2 next-20210920] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Christoph-Hellwig/nvdimm-pmem-fix-creating-the-dax-group/20210920-162804 base: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next config: riscv-buildonly-randconfig-r006-20210920 (attached as .config) compiler: riscv64-linux-gcc (GCC) 11.2.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/1a16d0f32f70bcd159a9f8cf32794f4024e8711e git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Christoph-Hellwig/nvdimm-pmem-fix-creating-the-dax-group/20210920-162804 git checkout 1a16d0f32f70bcd159a9f8cf32794f4024e8711e # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=riscv If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@intel.com> All errors (new ones prefixed by >>): drivers/dax/super.c:375:6: error: no previous prototype for 'run_dax' [-Werror=missing-prototypes] 375 | void run_dax(struct dax_device *dax_dev) | ^~~~~~~ >> drivers/dax/super.c:70:27: error: 'dax_get_by_host' defined but not used [-Werror=unused-function] 70 | static struct dax_device *dax_get_by_host(const char *host) | ^~~~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +/dax_get_by_host +70 drivers/dax/super.c 1b7646014e0d838b Christoph Hellwig 2021-08-26 65 1b7646014e0d838b Christoph Hellwig 2021-08-26 66 /** 1b7646014e0d838b Christoph Hellwig 2021-08-26 67 * dax_get_by_host() - temporary lookup mechanism for filesystem-dax 1b7646014e0d838b Christoph Hellwig 2021-08-26 68 * @host: alternate name for the device registered by a dax driver 1b7646014e0d838b Christoph Hellwig 2021-08-26 69 */ 1b7646014e0d838b Christoph Hellwig 2021-08-26 @70 static struct dax_device *dax_get_by_host(const char *host) 1b7646014e0d838b Christoph Hellwig 2021-08-26 71 { 1b7646014e0d838b Christoph Hellwig 2021-08-26 72 struct dax_device *dax_dev, *found = NULL; 1b7646014e0d838b Christoph Hellwig 2021-08-26 73 int hash, id; 1b7646014e0d838b Christoph Hellwig 2021-08-26 74 1b7646014e0d838b Christoph Hellwig 2021-08-26 75 if (!host) 1b7646014e0d838b Christoph Hellwig 2021-08-26 76 return NULL; 1b7646014e0d838b Christoph Hellwig 2021-08-26 77 1b7646014e0d838b Christoph Hellwig 2021-08-26 78 hash = dax_host_hash(host); 1b7646014e0d838b Christoph Hellwig 2021-08-26 79 1b7646014e0d838b Christoph Hellwig 2021-08-26 80 id = dax_read_lock(); 1b7646014e0d838b Christoph Hellwig 2021-08-26 81 spin_lock(&dax_host_lock); 1b7646014e0d838b Christoph Hellwig 2021-08-26 82 hlist_for_each_entry(dax_dev, &dax_host_list[hash], list) { 1b7646014e0d838b Christoph Hellwig 2021-08-26 83 if (!dax_alive(dax_dev) 1b7646014e0d838b Christoph Hellwig 2021-08-26 84 || strcmp(host, dax_dev->host) != 0) 1b7646014e0d838b Christoph Hellwig 2021-08-26 85 continue; 1b7646014e0d838b Christoph Hellwig 2021-08-26 86 1b7646014e0d838b Christoph Hellwig 2021-08-26 87 if (igrab(&dax_dev->inode)) 1b7646014e0d838b Christoph Hellwig 2021-08-26 88 found = dax_dev; 1b7646014e0d838b Christoph Hellwig 2021-08-26 89 break; 1b7646014e0d838b Christoph Hellwig 2021-08-26 90 } 1b7646014e0d838b Christoph Hellwig 2021-08-26 91 spin_unlock(&dax_host_lock); 1b7646014e0d838b Christoph Hellwig 2021-08-26 92 dax_read_unlock(id); 1b7646014e0d838b Christoph Hellwig 2021-08-26 93 1b7646014e0d838b Christoph Hellwig 2021-08-26 94 return found; 1b7646014e0d838b Christoph Hellwig 2021-08-26 95 } 1b7646014e0d838b Christoph Hellwig 2021-08-26 96 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org [-- Attachment #2: .config.gz --] [-- Type: application/gzip, Size: 28763 bytes --] ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem 2021-09-20 18:00 ` kernel test robot @ 2021-09-20 23:29 ` Dan Williams 0 siblings, 0 replies; 13+ messages in thread From: Dan Williams @ 2021-09-20 23:29 UTC (permalink / raw) To: kernel test robot Cc: Christoph Hellwig, Jens Axboe, kbuild-all, Vishal Verma, Dave Jiang, Ira Weiny, linux-block, Linux NVDIMM On Mon, Sep 20, 2021 at 11:01 AM kernel test robot <lkp@intel.com> wrote: > > Hi Christoph, > > I love your patch! Yet something to improve: > > [auto build test ERROR on axboe-block/for-next] > [also build test ERROR on linus/master v5.15-rc2 next-20210920] > [If your patch is applied to the wrong git tree, kindly drop us a note. > And when submitting patch, we suggest to use '--base' as documented in > https://git-scm.com/docs/git-format-patch] > > url: https://github.com/0day-ci/linux/commits/Christoph-Hellwig/nvdimm-pmem-fix-creating-the-dax-group/20210920-162804 > base: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next > config: riscv-buildonly-randconfig-r006-20210920 (attached as .config) > compiler: riscv64-linux-gcc (GCC) 11.2.0 > reproduce (this is a W=1 build): > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > # https://github.com/0day-ci/linux/commit/1a16d0f32f70bcd159a9f8cf32794f4024e8711e > git remote add linux-review https://github.com/0day-ci/linux > git fetch --no-tags linux-review Christoph-Hellwig/nvdimm-pmem-fix-creating-the-dax-group/20210920-162804 > git checkout 1a16d0f32f70bcd159a9f8cf32794f4024e8711e > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=riscv > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@intel.com> > > All errors (new ones prefixed by >>): > > drivers/dax/super.c:375:6: error: no previous prototype for 'run_dax' [-Werror=missing-prototypes] > 375 | void run_dax(struct dax_device *dax_dev) > | ^~~~~~~ In this new -Werror world drivers/dax/bus.c needs: #include "bus.h" > >> drivers/dax/super.c:70:27: error: 'dax_get_by_host' defined but not used [-Werror=unused-function] > 70 | static struct dax_device *dax_get_by_host(const char *host) > | ^~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors Nice additional cleanup that now fs_dax_get_by_bdev() is the only caller of dax_get_by_host(). ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem 2021-09-20 7:27 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig 2021-09-20 18:00 ` kernel test robot @ 2021-09-20 22:51 ` Ira Weiny 2021-09-20 23:36 ` Dan Williams 2021-09-20 23:37 ` Dan Williams 2 siblings, 1 reply; 13+ messages in thread From: Ira Weiny @ 2021-09-20 22:51 UTC (permalink / raw) To: Christoph Hellwig, Dan Williams Cc: Dan Williams, Jens Axboe, Vishal Verma, Dave Jiang, linux-block, nvdimm On Mon, Sep 20, 2021 at 09:27:25AM +0200, Christoph Hellwig wrote: ... > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c > index ef4950f808326..bbeb3f46db157 100644 > --- a/drivers/nvdimm/pmem.c > +++ b/drivers/nvdimm/pmem.c > @@ -328,6 +328,49 @@ static const struct dax_operations pmem_dax_ops = { > .zero_page_range = pmem_dax_zero_page_range, > }; > > +static ssize_t write_cache_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct pmem_device *pmem = dev_to_disk(dev)->private_data; I want to say this should be dax_get_private()... However, looking at the use of dax_get_private() not a single caller checks for NULL! :-( So now I wonder why dax_get_private() exists... :-/ A quick history search does not make anything apparent. When the DAXDEV_ALIVE check was added to dax_get_private() no callers were changed to account for a potential NULL return. Dan? > + > + return sprintf(buf, "%d\n", !!dax_write_cache_enabled(pmem->dax_dev)); > +} > + > +static ssize_t write_cache_store(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t len) > +{ > + struct pmem_device *pmem = dev_to_disk(dev)->private_data; Same here... Ira ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem 2021-09-20 22:51 ` Ira Weiny @ 2021-09-20 23:36 ` Dan Williams 0 siblings, 0 replies; 13+ messages in thread From: Dan Williams @ 2021-09-20 23:36 UTC (permalink / raw) To: Ira Weiny Cc: Christoph Hellwig, Jens Axboe, Vishal Verma, Dave Jiang, linux-block, Linux NVDIMM On Mon, Sep 20, 2021 at 3:51 PM Ira Weiny <ira.weiny@intel.com> wrote: > > On Mon, Sep 20, 2021 at 09:27:25AM +0200, Christoph Hellwig wrote: > > ... > > > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c > > index ef4950f808326..bbeb3f46db157 100644 > > --- a/drivers/nvdimm/pmem.c > > +++ b/drivers/nvdimm/pmem.c > > @@ -328,6 +328,49 @@ static const struct dax_operations pmem_dax_ops = { > > .zero_page_range = pmem_dax_zero_page_range, > > }; > > > > +static ssize_t write_cache_show(struct device *dev, > > + struct device_attribute *attr, char *buf) > > +{ > > + struct pmem_device *pmem = dev_to_disk(dev)->private_data; > > I want to say this should be dax_get_private()... However, looking at the use No, this wants to do from @dev to @dax_dev. dax_get_private() assumes that @dax_dev is already known. Also, in this case @dev is the gendisk device, so this is a gendisk-to-dax-device with special knowledge that the gendisk is for a pmem device. > of dax_get_private() not a single caller checks for NULL! :-( All the callers are correctly assuming that their usage is before kill_dax(). > > So now I wonder why dax_get_private() exists... :-/ It exists so that the definition of 'struct dax_device' can remain private, as no one should be directly mucking with dax_device internals outside of the provided APIs. > A quick history search does not make anything apparent. When the DAXDEV_ALIVE > check was added to dax_get_private() no callers were changed to account for a > potential NULL return. > > Dan? I double checked, but this all looks ok to me. ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem 2021-09-20 7:27 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig 2021-09-20 18:00 ` kernel test robot 2021-09-20 22:51 ` Ira Weiny @ 2021-09-20 23:37 ` Dan Williams 2 siblings, 0 replies; 13+ messages in thread From: Dan Williams @ 2021-09-20 23:37 UTC (permalink / raw) To: Christoph Hellwig Cc: Jens Axboe, Vishal Verma, Dave Jiang, Ira Weiny, linux-block, Linux NVDIMM On Mon, Sep 20, 2021 at 12:29 AM Christoph Hellwig <hch@lst.de> wrote: > > dax_attribute_group is only used by the pmem driver, and can avoid the > completely pointless lookup by the disk name if moved there. After the additional fixups that 0day-robot found, you can add: Reviewed-by: Dan Williams <dan.j.williams@intel.com> ^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2021-09-27 18:19 UTC | newest] Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-09-22 18:33 fix a dax/block device attribute registration regression Christoph Hellwig 2021-09-22 18:33 ` [PATCH 1/3] nvdimm/pmem: fix creating the dax group Christoph Hellwig 2021-09-22 18:33 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig 2021-09-22 21:40 ` Ira Weiny 2021-09-22 18:33 ` [PATCH 3/3] block: warn if ->groups is set when calling add_disk Christoph Hellwig 2021-09-27 18:19 ` fix a dax/block device attribute registration regression Dan Williams -- strict thread matches above, loose matches on Subject: below -- 2021-09-22 17:34 dax_supported() related cleanups v2 Christoph Hellwig 2021-09-22 17:34 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig 2021-09-20 7:27 fix a dax/block device attribute registration regression Christoph Hellwig 2021-09-20 7:27 ` [PATCH 2/3] nvdimm/pmem: move dax_attribute_group from dax to pmem Christoph Hellwig 2021-09-20 18:00 ` kernel test robot 2021-09-20 23:29 ` Dan Williams 2021-09-20 22:51 ` Ira Weiny 2021-09-20 23:36 ` Dan Williams 2021-09-20 23:37 ` Dan Williams
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