search for: daxdev_mapping_supported

On Wed 10-04-19 09:38:24, Pankaj Gupta wrote: > This patch introduces 'daxdev_mapping_supported' helper > which checks if 'MAP_SYNC' is supported with filesystem > mapping. It also checks if corresponding dax_device is > synchronous. Virtio pmem device is asynchronous and > does not not support VM_SYNC. > > Suggested-by: Jan Kara <jack at suse.cz> > Si...

This patch introduces 'daxdev_mapping_supported' helper which checks if 'MAP_SYNC' is supported with filesystem mapping. It also checks if corresponding dax_device is synchronous. Virtio pmem device is asynchronous and does not not support VM_SYNC. Suggested-by: Jan Kara <jack at suse.cz> Signed-off-by: Pankaj Gupta <pagup...

This patch introduces 'daxdev_mapping_supported' helper which checks if 'MAP_SYNC' is supported with filesystem mapping. It also checks if corresponding dax_device is synchronous. Virtio pmem device is asynchronous and does not not support VM_SYNC. Suggested-by: Jan Kara <jack at suse.cz> Signed-off-by: Pankaj Gupta <pagup...

This patch introduces 'daxdev_mapping_supported' helper which checks if 'MAP_SYNC' is supported with filesystem mapping. It also checks if corresponding dax_device is synchronous. Virtio pmem device is asynchronous and does not not support VM_SYNC. Suggested-by: Jan Kara <jack at suse.cz> Signed-off-by: Pankaj Gupta <pagup...

...a sensible use case. > + * We don't support synchronous mappings for non-DAX files and > + * for DAX files if underneath dax_device is not synchronous. > */ > - if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC)) > + if (!daxdev_mapping_supported(vma, dax_dev)) > return -EOPNOTSUPP; > > file_accessed(filp); > -- > 2.20.1 >

...a sensible use case. > + * We don't support synchronous mappings for non-DAX files and > + * for DAX files if underneath dax_device is not synchronous. > */ > - if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC)) > + if (!daxdev_mapping_supported(vma, dax_dev)) > return -EOPNOTSUPP; > > file_accessed(filp); > -- > 2.20.1 >

From: Pankaj Gupta <pagupta at redhat.com> Date: Thu, Apr 25, 2019 at 10:00 PM > +static inline bool daxdev_mapping_supported(struct vm_area_struct *vma, > + struct dax_device *dax_dev) > +{ > + return !(vma->flags & VM_SYNC); > +} Shouldn't it be rather `return !(vma->vm_flags & VM_SYNC);`? There is no field named `flags` in `struct vm_area_struct`. Than...

From: Pankaj Gupta <pagupta at redhat.com> Date: Thu, Apr 25, 2019 at 10:00 PM > +static inline bool daxdev_mapping_supported(struct vm_area_struct *vma, > + struct dax_device *dax_dev) > +{ > + return !(vma->flags & VM_SYNC); > +} Shouldn't it be rather `return !(vma->vm_flags & VM_SYNC);`? There is no field named `flags` in `struct vm_area_struct`. Than...

...ny change? Changes from PATCH v5: [1] Changes suggested in by - [Cornelia, Yuval] - Remove assignment chaining in virtio driver - Better error message and remove not required free - Check nd_region before use Changes suggested by - [Jan Kara] - dax_synchronous() for !CONFIG_DAX - Correct 'daxdev_mapping_supported' comment and non-dax implementation Changes suggested by - [Dan Williams] - Pass meaningful flag 'DAXDEV_F_SYNC' to alloc_dax - Gate nvdimm_flush instead of additional async parameter - Move block chaining logic to flush callback than common nvdimm_flush - Use NULL flush callback for...

...- * until someone comes with a sensible use case. > + /* We don't support synchronous mappings for non-DAX files and > + * for DAX files if underneath dax_device is not synchronous. > */ > - if (!IS_DAX(file_inode(file)) && (vma->vm_flags & VM_SYNC)) > + if (!daxdev_mapping_supported(vma, dax_dev)) > return -EOPNOTSUPP; > > file_accessed(file); > -- > 2.20.1 > -- Jan Kara <jack at suse.com> SUSE Labs, CR

...unction in "fs.h" it > > will be compiled for every filesystem, even for those don't need it. > > > > Sample patch below, does below patch is near to what you have in mind? > > So I would put the helper in include/linux/dax.h and have it like: > > bool daxdev_mapping_supported(struct vm_area_struct *vma, > struct dax_device *dax_dev) > { > if (!(vma->vm_flags & VM_SYNC)) > return true; > if (!IS_DAX(file_inode(vma->vm_file))) > return false; > return dax_synchronous(dax_dev); > } Sure. This is much better. I was also not...

...unction in "fs.h" it > > will be compiled for every filesystem, even for those don't need it. > > > > Sample patch below, does below patch is near to what you have in mind? > > So I would put the helper in include/linux/dax.h and have it like: > > bool daxdev_mapping_supported(struct vm_area_struct *vma, > struct dax_device *dax_dev) > { > if (!(vma->vm_flags & VM_SYNC)) > return true; > if (!IS_DAX(file_inode(vma->vm_file))) > return false; > return dax_synchronous(dax_dev); > } Sure. This is much better. I was also not...

...& patch 5 Changes from PATCH v5: Changes suggested in by - [Cornelia, Yuval] - Remove assignment chaining in virtio driver - Better error message and remove not required free - Check nd_region before use Changes suggested by - [Jan Kara] - dax_synchronous() for !CONFIG_DAX - Correct 'daxdev_mapping_supported' comment and non-dax implementation Changes suggested by - [Dan Williams] - Pass meaningful flag 'DAXDEV_F_SYNC' to alloc_dax - Gate nvdimm_flush instead of additional async parameter - Move block chaining logic to flush callback than common nvdimm_flush - Use NULL flush callback for...

...& patch 5 Changes from PATCH v5: Changes suggested in by - [Cornelia, Yuval] - Remove assignment chaining in virtio driver - Better error message and remove not required free - Check nd_region before use Changes suggested by - [Jan Kara] - dax_synchronous() for !CONFIG_DAX - Correct 'daxdev_mapping_supported' comment and non-dax implementation Changes suggested by - [Dan Williams] - Pass meaningful flag 'DAXDEV_F_SYNC' to alloc_dax - Gate nvdimm_flush instead of additional async parameter - Move block chaining logic to flush callback than common nvdimm_flush - Use NULL flush callback for...

This patch series has implementation for "virtio pmem". "virtio pmem" is fake persistent memory(nvdimm) in guest which allows to bypass the guest page cache. This also implements a VIRTIO based asynchronous flush mechanism. Sharing guest kernel driver in this patchset with the changes suggested in v4. Tested with Qemu side device emulation [6] for virtio-pmem.

...& patch 5 Changes from PATCH v5: Changes suggested in by - [Cornelia, Yuval] - Remove assignment chaining in virtio driver - Better error message and remove not required free - Check nd_region before use Changes suggested by - [Jan Kara] - dax_synchronous() for !CONFIG_DAX - Correct 'daxdev_mapping_supported' comment and non-dax implementation Changes suggested by - [Dan Williams] - Pass meaningful flag 'DAXDEV_F_SYNC' to alloc_dax - Gate nvdimm_flush instead of additional async parameter - Move block chaining logic to flush callback than common nvdimm_flush - Use NULL flush callback for...

...& patch 5 Changes from PATCH v5: Changes suggested in by - [Cornelia, Yuval] - Remove assignment chaining in virtio driver - Better error message and remove not required free - Check nd_region before use Changes suggested by - [Jan Kara] - dax_synchronous() for !CONFIG_DAX - Correct 'daxdev_mapping_supported' comment and non-dax implementation Changes suggested by - [Dan Williams] - Pass meaningful flag 'DAXDEV_F_SYNC' to alloc_dax - Gate nvdimm_flush instead of additional async parameter - Move block chaining logic to flush callback than common nvdimm_flush - Use NULL flush callback for...

...& patch 5 Changes from PATCH v5: Changes suggested in by - [Cornelia, Yuval] - Remove assignment chaining in virtio driver - Better error message and remove not required free - Check nd_region before use Changes suggested by - [Jan Kara] - dax_synchronous() for !CONFIG_DAX - Correct 'daxdev_mapping_supported' comment and non-dax implementation Changes suggested by - [Dan Williams] - Pass meaningful flag 'DAXDEV_F_SYNC' to alloc_dax - Gate nvdimm_flush instead of additional async parameter - Move block chaining logic to flush callback than common nvdimm_flush - Use NULL flush callback for...

...p; patch 5 Changes from PATCH v5: [2] Changes suggested in by - [Cornelia, Yuval] - Remove assignment chaining in virtio driver - Better error message and remove not required free - Check nd_region before use Changes suggested by - [Jan Kara] - dax_synchronous() for !CONFIG_DAX - Correct 'daxdev_mapping_supported' comment and non-dax implementation Changes suggested by - [Dan Williams] - Pass meaningful flag 'DAXDEV_F_SYNC' to alloc_dax - Gate nvdimm_flush instead of additional async parameter - Move block chaining logic to flush callback than common nvdimm_flush - Use NULL flush callback for...

> > On Thu, Apr 04, 2019 at 09:09:12AM +1100, Dave Chinner wrote: > > > On Wed, Apr 03, 2019 at 04:10:18PM +0530, Pankaj Gupta wrote: > > > > Virtio pmem provides asynchronous host page cache flush > > > > mechanism. we don't support 'MAP_SYNC' with virtio pmem > > > > and xfs. > > > > > > > > Signed-off-by: