| Message ID | 20240208184913.484340-3-mathieu.desnoyers@efficios.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Introduce cpu_dcache_is_aliasing() to fix DAX regression | expand |
Mathieu Desnoyers wrote: > In preparation for checking whether the architecture has data cache > aliasing within alloc_dax(), modify the error handling of nvdimm/pmem > pmem_attach_disk() to treat alloc_dax() -EOPNOTSUPP failure as non-fatal. > > For the transition, consider that alloc_dax() returning NULL is the > same as returning -EOPNOTSUPP. > > Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches") > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > Cc: Alasdair Kergon <agk@redhat.com> > Cc: Mike Snitzer <snitzer@kernel.org> > Cc: Mikulas Patocka <mpatocka@redhat.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Vishal Verma <vishal.l.verma@intel.com> > Cc: Dave Jiang <dave.jiang@intel.com> > Cc: Matthew Wilcox <willy@infradead.org> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Russell King <linux@armlinux.org.uk> > Cc: linux-arch@vger.kernel.org > Cc: linux-cxl@vger.kernel.org > Cc: linux-fsdevel@vger.kernel.org > Cc: linux-mm@kvack.org > Cc: linux-xfs@vger.kernel.org > Cc: dm-devel@lists.linux.dev > Cc: nvdimm@lists.linux.dev > --- > drivers/nvdimm/pmem.c | 26 ++++++++++++++------------ > 1 file changed, 14 insertions(+), 12 deletions(-) > > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c > index 9fe358090720..f1d9f5c6dbac 100644 > --- a/drivers/nvdimm/pmem.c > +++ b/drivers/nvdimm/pmem.c > @@ -558,19 +558,21 @@ static int pmem_attach_disk(struct device *dev, > disk->bb = &pmem->bb; > > dax_dev = alloc_dax(pmem, &pmem_dax_ops); > - if (IS_ERR(dax_dev)) { > - rc = PTR_ERR(dax_dev); > - goto out; > + if (IS_ERR_OR_NULL(dax_dev)) { alloc_dax() should never return NULL. I.e. the lead in before this patch should fix this misunderstanding: diff --git a/include/linux/dax.h b/include/linux/dax.h index b463502b16e1..df2d52b8a245 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -86,11 +86,7 @@ static inline void *dax_holder(struct dax_device *dax_dev) static inline struct dax_device *alloc_dax(void *private, const struct dax_operations *ops) { - /* - * Callers should check IS_ENABLED(CONFIG_DAX) to know if this - * NULL is an error or expected. - */ - return NULL; + return ERR_PTR(-EOPNOTSUPP); } static inline void put_dax(struct dax_device *dax_dev) { > + rc = IS_ERR(dax_dev) ? PTR_ERR(dax_dev) : -EOPNOTSUPP; Then this ternary can be replaced with just a check of which PTR_ERR() value is being returned.
On 2024-02-08 16:32, Dan Williams wrote: > Mathieu Desnoyers wrote: >> In preparation for checking whether the architecture has data cache >> aliasing within alloc_dax(), modify the error handling of nvdimm/pmem >> pmem_attach_disk() to treat alloc_dax() -EOPNOTSUPP failure as non-fatal. >> >> For the transition, consider that alloc_dax() returning NULL is the >> same as returning -EOPNOTSUPP. >> >> Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches") >> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> >> Cc: Alasdair Kergon <agk@redhat.com> >> Cc: Mike Snitzer <snitzer@kernel.org> >> Cc: Mikulas Patocka <mpatocka@redhat.com> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: Linus Torvalds <torvalds@linux-foundation.org> >> Cc: Dan Williams <dan.j.williams@intel.com> >> Cc: Vishal Verma <vishal.l.verma@intel.com> >> Cc: Dave Jiang <dave.jiang@intel.com> >> Cc: Matthew Wilcox <willy@infradead.org> >> Cc: Arnd Bergmann <arnd@arndb.de> >> Cc: Russell King <linux@armlinux.org.uk> >> Cc: linux-arch@vger.kernel.org >> Cc: linux-cxl@vger.kernel.org >> Cc: linux-fsdevel@vger.kernel.org >> Cc: linux-mm@kvack.org >> Cc: linux-xfs@vger.kernel.org >> Cc: dm-devel@lists.linux.dev >> Cc: nvdimm@lists.linux.dev >> --- >> drivers/nvdimm/pmem.c | 26 ++++++++++++++------------ >> 1 file changed, 14 insertions(+), 12 deletions(-) >> >> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c >> index 9fe358090720..f1d9f5c6dbac 100644 >> --- a/drivers/nvdimm/pmem.c >> +++ b/drivers/nvdimm/pmem.c >> @@ -558,19 +558,21 @@ static int pmem_attach_disk(struct device *dev, >> disk->bb = &pmem->bb; >> >> dax_dev = alloc_dax(pmem, &pmem_dax_ops); >> - if (IS_ERR(dax_dev)) { >> - rc = PTR_ERR(dax_dev); >> - goto out; >> + if (IS_ERR_OR_NULL(dax_dev)) { > > alloc_dax() should never return NULL. I.e. the lead in before this patch > should fix this misunderstanding: > > diff --git a/include/linux/dax.h b/include/linux/dax.h > index b463502b16e1..df2d52b8a245 100644 > --- a/include/linux/dax.h > +++ b/include/linux/dax.h > @@ -86,11 +86,7 @@ static inline void *dax_holder(struct dax_device *dax_dev) > static inline struct dax_device *alloc_dax(void *private, > const struct dax_operations *ops) > { > - /* > - * Callers should check IS_ENABLED(CONFIG_DAX) to know if this > - * NULL is an error or expected. > - */ > - return NULL; > + return ERR_PTR(-EOPNOTSUPP); > } > static inline void put_dax(struct dax_device *dax_dev) > { > >> + rc = IS_ERR(dax_dev) ? PTR_ERR(dax_dev) : -EOPNOTSUPP; > > Then this ternary can be replaced with just a check of which PTR_ERR() > value is being returned. As you noted, I've introduced this as cleanups in later patches. I don't mind folding these into their respective per-driver commits and moving the alloc_dax() hunk earlier in the series. Thanks, Mathieu
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 9fe358090720..f1d9f5c6dbac 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -558,19 +558,21 @@ static int pmem_attach_disk(struct device *dev, disk->bb = &pmem->bb; dax_dev = alloc_dax(pmem, &pmem_dax_ops); - if (IS_ERR(dax_dev)) { - rc = PTR_ERR(dax_dev); - goto out; + if (IS_ERR_OR_NULL(dax_dev)) { + rc = IS_ERR(dax_dev) ? PTR_ERR(dax_dev) : -EOPNOTSUPP; + if (rc != -EOPNOTSUPP) + goto out; + } else { + set_dax_nocache(dax_dev); + set_dax_nomc(dax_dev); + if (is_nvdimm_sync(nd_region)) + set_dax_synchronous(dax_dev); + pmem->dax_dev = dax_dev; + rc = dax_add_host(dax_dev, disk); + if (rc) + goto out_cleanup_dax; + dax_write_cache(dax_dev, nvdimm_has_cache(nd_region)); } - set_dax_nocache(dax_dev); - set_dax_nomc(dax_dev); - if (is_nvdimm_sync(nd_region)) - set_dax_synchronous(dax_dev); - pmem->dax_dev = dax_dev; - rc = dax_add_host(dax_dev, disk); - if (rc) - goto out_cleanup_dax; - dax_write_cache(dax_dev, nvdimm_has_cache(nd_region)); rc = device_add_disk(dev, disk, pmem_attribute_groups); if (rc) goto out_remove_host;
In preparation for checking whether the architecture has data cache aliasing within alloc_dax(), modify the error handling of nvdimm/pmem pmem_attach_disk() to treat alloc_dax() -EOPNOTSUPP failure as non-fatal. For the transition, consider that alloc_dax() returning NULL is the same as returning -EOPNOTSUPP. Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: linux-arch@vger.kernel.org Cc: linux-cxl@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: dm-devel@lists.linux.dev Cc: nvdimm@lists.linux.dev --- drivers/nvdimm/pmem.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-)