| Message ID | 20190309120721.21416-1-aneesh.kumar@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] fs/dax: deposit pagetable even when installing zero page | expand |
Hi Dan/Andrew/Jan, "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes: > Architectures like ppc64 use the deposited page table to store hardware > page table slot information. Make sure we deposit a page table when > using zero page at the pmd level for hash. > > Without this we hit > > Unable to handle kernel paging request for data at address 0x00000000 > Faulting instruction address: 0xc000000000082a74 > Oops: Kernel access of bad area, sig: 11 [#1] > .... > > NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0 > LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0 > Call Trace: > hash_page_mm+0x43c/0x740 > do_hash_page+0x2c/0x3c > copy_from_iter_flushcache+0xa4/0x4a0 > pmem_copy_from_iter+0x2c/0x50 [nd_pmem] > dax_copy_from_iter+0x40/0x70 > dax_iomap_actor+0x134/0x360 > iomap_apply+0xfc/0x1b0 > dax_iomap_rw+0xac/0x130 > ext4_file_write_iter+0x254/0x460 [ext4] > __vfs_write+0x120/0x1e0 > vfs_write+0xd8/0x220 > SyS_write+0x6c/0x110 > system_call+0x3c/0x130 > > Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") > Reviewed-by: Jan Kara <jack@suse.cz> > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Any suggestion on which tree this patch should got to? Also since this fix a kernel crash, we may want to get this to 5.1? > --- > Changes from v1: > * Add reviewed-by: > * Add Fixes: > > fs/dax.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/fs/dax.c b/fs/dax.c > index 6959837cc465..01bfb2ac34f9 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -33,6 +33,7 @@ > #include <linux/sizes.h> > #include <linux/mmu_notifier.h> > #include <linux/iomap.h> > +#include <asm/pgalloc.h> > #include "internal.h" > > #define CREATE_TRACE_POINTS > @@ -1410,7 +1411,9 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, > { > struct address_space *mapping = vmf->vma->vm_file->f_mapping; > unsigned long pmd_addr = vmf->address & PMD_MASK; > + struct vm_area_struct *vma = vmf->vma; > struct inode *inode = mapping->host; > + pgtable_t pgtable = NULL; > struct page *zero_page; > spinlock_t *ptl; > pmd_t pmd_entry; > @@ -1425,12 +1428,22 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, > *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, > DAX_PMD | DAX_ZERO_PAGE, false); > > + if (arch_needs_pgtable_deposit()) { > + pgtable = pte_alloc_one(vma->vm_mm); > + if (!pgtable) > + return VM_FAULT_OOM; > + } > + > ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); > if (!pmd_none(*(vmf->pmd))) { > spin_unlock(ptl); > goto fallback; > } > > + if (pgtable) { > + pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); > + mm_inc_nr_ptes(vma->vm_mm); > + } > pmd_entry = mk_pmd(zero_page, vmf->vma->vm_page_prot); > pmd_entry = pmd_mkhuge(pmd_entry); > set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry); > @@ -1439,6 +1452,8 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, > return VM_FAULT_NOPAGE; > > fallback: > + if (pgtable) > + pte_free(vma->vm_mm, pgtable); > trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, *entry); > return VM_FAULT_FALLBACK; > } > -- > 2.20.1 -aneesh
On Wed 13-03-19 10:17:17, Aneesh Kumar K.V wrote: > > Hi Dan/Andrew/Jan, > > "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes: > > > Architectures like ppc64 use the deposited page table to store hardware > > page table slot information. Make sure we deposit a page table when > > using zero page at the pmd level for hash. > > > > Without this we hit > > > > Unable to handle kernel paging request for data at address 0x00000000 > > Faulting instruction address: 0xc000000000082a74 > > Oops: Kernel access of bad area, sig: 11 [#1] > > .... > > > > NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0 > > LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0 > > Call Trace: > > hash_page_mm+0x43c/0x740 > > do_hash_page+0x2c/0x3c > > copy_from_iter_flushcache+0xa4/0x4a0 > > pmem_copy_from_iter+0x2c/0x50 [nd_pmem] > > dax_copy_from_iter+0x40/0x70 > > dax_iomap_actor+0x134/0x360 > > iomap_apply+0xfc/0x1b0 > > dax_iomap_rw+0xac/0x130 > > ext4_file_write_iter+0x254/0x460 [ext4] > > __vfs_write+0x120/0x1e0 > > vfs_write+0xd8/0x220 > > SyS_write+0x6c/0x110 > > system_call+0x3c/0x130 > > > > Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") > > Reviewed-by: Jan Kara <jack@suse.cz> > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > > Any suggestion on which tree this patch should got to? Also since this > fix a kernel crash, we may want to get this to 5.1? I think this should go through Dan's tree... Honza > > --- > > Changes from v1: > > * Add reviewed-by: > > * Add Fixes: > > > > fs/dax.c | 15 +++++++++++++++ > > 1 file changed, 15 insertions(+) > > > > diff --git a/fs/dax.c b/fs/dax.c > > index 6959837cc465..01bfb2ac34f9 100644 > > --- a/fs/dax.c > > +++ b/fs/dax.c > > @@ -33,6 +33,7 @@ > > #include <linux/sizes.h> > > #include <linux/mmu_notifier.h> > > #include <linux/iomap.h> > > +#include <asm/pgalloc.h> > > #include "internal.h" > > > > #define CREATE_TRACE_POINTS > > @@ -1410,7 +1411,9 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, > > { > > struct address_space *mapping = vmf->vma->vm_file->f_mapping; > > unsigned long pmd_addr = vmf->address & PMD_MASK; > > + struct vm_area_struct *vma = vmf->vma; > > struct inode *inode = mapping->host; > > + pgtable_t pgtable = NULL; > > struct page *zero_page; > > spinlock_t *ptl; > > pmd_t pmd_entry; > > @@ -1425,12 +1428,22 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, > > *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, > > DAX_PMD | DAX_ZERO_PAGE, false); > > > > + if (arch_needs_pgtable_deposit()) { > > + pgtable = pte_alloc_one(vma->vm_mm); > > + if (!pgtable) > > + return VM_FAULT_OOM; > > + } > > + > > ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); > > if (!pmd_none(*(vmf->pmd))) { > > spin_unlock(ptl); > > goto fallback; > > } > > > > + if (pgtable) { > > + pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); > > + mm_inc_nr_ptes(vma->vm_mm); > > + } > > pmd_entry = mk_pmd(zero_page, vmf->vma->vm_page_prot); > > pmd_entry = pmd_mkhuge(pmd_entry); > > set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry); > > @@ -1439,6 +1452,8 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, > > return VM_FAULT_NOPAGE; > > > > fallback: > > + if (pgtable) > > + pte_free(vma->vm_mm, pgtable); > > trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, *entry); > > return VM_FAULT_FALLBACK; > > } > > -- > > 2.20.1 > > -aneesh >
On Wed, Mar 13, 2019 at 2:58 AM Jan Kara <jack@suse.cz> wrote: > > On Wed 13-03-19 10:17:17, Aneesh Kumar K.V wrote: > > > > Hi Dan/Andrew/Jan, > > > > "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes: > > > > > Architectures like ppc64 use the deposited page table to store hardware > > > page table slot information. Make sure we deposit a page table when > > > using zero page at the pmd level for hash. > > > > > > Without this we hit > > > > > > Unable to handle kernel paging request for data at address 0x00000000 > > > Faulting instruction address: 0xc000000000082a74 > > > Oops: Kernel access of bad area, sig: 11 [#1] > > > .... > > > > > > NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0 > > > LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0 > > > Call Trace: > > > hash_page_mm+0x43c/0x740 > > > do_hash_page+0x2c/0x3c > > > copy_from_iter_flushcache+0xa4/0x4a0 > > > pmem_copy_from_iter+0x2c/0x50 [nd_pmem] > > > dax_copy_from_iter+0x40/0x70 > > > dax_iomap_actor+0x134/0x360 > > > iomap_apply+0xfc/0x1b0 > > > dax_iomap_rw+0xac/0x130 > > > ext4_file_write_iter+0x254/0x460 [ext4] > > > __vfs_write+0x120/0x1e0 > > > vfs_write+0xd8/0x220 > > > SyS_write+0x6c/0x110 > > > system_call+0x3c/0x130 > > > > > > Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") > > > Reviewed-by: Jan Kara <jack@suse.cz> > > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > > > > Any suggestion on which tree this patch should got to? Also since this > > fix a kernel crash, we may want to get this to 5.1? > > I think this should go through Dan's tree... I'll merge this and let it soak in -next for a week and then submit for 5.1-rc2.
Hi Dan, Dan Williams <dan.j.williams@intel.com> writes: > On Wed, Mar 13, 2019 at 2:58 AM Jan Kara <jack@suse.cz> wrote: >> >> On Wed 13-03-19 10:17:17, Aneesh Kumar K.V wrote: >> > >> > Hi Dan/Andrew/Jan, >> > >> > "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes: >> > >> > > Architectures like ppc64 use the deposited page table to store hardware >> > > page table slot information. Make sure we deposit a page table when >> > > using zero page at the pmd level for hash. >> > > >> > > Without this we hit >> > > >> > > Unable to handle kernel paging request for data at address 0x00000000 >> > > Faulting instruction address: 0xc000000000082a74 >> > > Oops: Kernel access of bad area, sig: 11 [#1] >> > > .... >> > > >> > > NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0 >> > > LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0 >> > > Call Trace: >> > > hash_page_mm+0x43c/0x740 >> > > do_hash_page+0x2c/0x3c >> > > copy_from_iter_flushcache+0xa4/0x4a0 >> > > pmem_copy_from_iter+0x2c/0x50 [nd_pmem] >> > > dax_copy_from_iter+0x40/0x70 >> > > dax_iomap_actor+0x134/0x360 >> > > iomap_apply+0xfc/0x1b0 >> > > dax_iomap_rw+0xac/0x130 >> > > ext4_file_write_iter+0x254/0x460 [ext4] >> > > __vfs_write+0x120/0x1e0 >> > > vfs_write+0xd8/0x220 >> > > SyS_write+0x6c/0x110 >> > > system_call+0x3c/0x130 >> > > >> > > Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") >> > > Reviewed-by: Jan Kara <jack@suse.cz> >> > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> >> > >> > Any suggestion on which tree this patch should got to? Also since this >> > fix a kernel crash, we may want to get this to 5.1? >> >> I think this should go through Dan's tree... > > I'll merge this and let it soak in -next for a week and then submit for 5.1-rc2. Any update on this? Did you get to merge this? -aneesh
On Mon, Apr 8, 2019 at 2:39 AM Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> wrote: > > > Hi Dan, > > Dan Williams <dan.j.williams@intel.com> writes: > > > On Wed, Mar 13, 2019 at 2:58 AM Jan Kara <jack@suse.cz> wrote: > >> > >> On Wed 13-03-19 10:17:17, Aneesh Kumar K.V wrote: > >> > > >> > Hi Dan/Andrew/Jan, > >> > > >> > "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> writes: > >> > > >> > > Architectures like ppc64 use the deposited page table to store hardware > >> > > page table slot information. Make sure we deposit a page table when > >> > > using zero page at the pmd level for hash. > >> > > > >> > > Without this we hit > >> > > > >> > > Unable to handle kernel paging request for data at address 0x00000000 > >> > > Faulting instruction address: 0xc000000000082a74 > >> > > Oops: Kernel access of bad area, sig: 11 [#1] > >> > > .... > >> > > > >> > > NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0 > >> > > LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0 > >> > > Call Trace: > >> > > hash_page_mm+0x43c/0x740 > >> > > do_hash_page+0x2c/0x3c > >> > > copy_from_iter_flushcache+0xa4/0x4a0 > >> > > pmem_copy_from_iter+0x2c/0x50 [nd_pmem] > >> > > dax_copy_from_iter+0x40/0x70 > >> > > dax_iomap_actor+0x134/0x360 > >> > > iomap_apply+0xfc/0x1b0 > >> > > dax_iomap_rw+0xac/0x130 > >> > > ext4_file_write_iter+0x254/0x460 [ext4] > >> > > __vfs_write+0x120/0x1e0 > >> > > vfs_write+0xd8/0x220 > >> > > SyS_write+0x6c/0x110 > >> > > system_call+0x3c/0x130 > >> > > > >> > > Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") > >> > > Reviewed-by: Jan Kara <jack@suse.cz> > >> > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> > >> > > >> > Any suggestion on which tree this patch should got to? Also since this > >> > fix a kernel crash, we may want to get this to 5.1? > >> > >> I think this should go through Dan's tree... > > > > I'll merge this and let it soak in -next for a week and then submit for 5.1-rc2. > > Any update on this? Did you get to merge this? Thanks for the reminder. Will send this week along with some other libnvdimm related fixes.
diff --git a/fs/dax.c b/fs/dax.c index 6959837cc465..01bfb2ac34f9 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -33,6 +33,7 @@ #include <linux/sizes.h> #include <linux/mmu_notifier.h> #include <linux/iomap.h> +#include <asm/pgalloc.h> #include "internal.h" #define CREATE_TRACE_POINTS @@ -1410,7 +1411,9 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, { struct address_space *mapping = vmf->vma->vm_file->f_mapping; unsigned long pmd_addr = vmf->address & PMD_MASK; + struct vm_area_struct *vma = vmf->vma; struct inode *inode = mapping->host; + pgtable_t pgtable = NULL; struct page *zero_page; spinlock_t *ptl; pmd_t pmd_entry; @@ -1425,12 +1428,22 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, DAX_PMD | DAX_ZERO_PAGE, false); + if (arch_needs_pgtable_deposit()) { + pgtable = pte_alloc_one(vma->vm_mm); + if (!pgtable) + return VM_FAULT_OOM; + } + ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); if (!pmd_none(*(vmf->pmd))) { spin_unlock(ptl); goto fallback; } + if (pgtable) { + pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); + mm_inc_nr_ptes(vma->vm_mm); + } pmd_entry = mk_pmd(zero_page, vmf->vma->vm_page_prot); pmd_entry = pmd_mkhuge(pmd_entry); set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry); @@ -1439,6 +1452,8 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, return VM_FAULT_NOPAGE; fallback: + if (pgtable) + pte_free(vma->vm_mm, pgtable); trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, *entry); return VM_FAULT_FALLBACK; }
Architectures like ppc64 use the deposited page table to store hardware page table slot information. Make sure we deposit a page table when using zero page at the pmd level for hash. Without this we hit Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc000000000082a74 Oops: Kernel access of bad area, sig: 11 [#1] .... NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0 LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0 Call Trace: hash_page_mm+0x43c/0x740 do_hash_page+0x2c/0x3c copy_from_iter_flushcache+0xa4/0x4a0 pmem_copy_from_iter+0x2c/0x50 [nd_pmem] dax_copy_from_iter+0x40/0x70 dax_iomap_actor+0x134/0x360 iomap_apply+0xfc/0x1b0 dax_iomap_rw+0xac/0x130 ext4_file_write_iter+0x254/0x460 [ext4] __vfs_write+0x120/0x1e0 vfs_write+0xd8/0x220 SyS_write+0x6c/0x110 system_call+0x3c/0x130 Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> --- Changes from v1: * Add reviewed-by: * Add Fixes: fs/dax.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)