On Tue, 24 Mar 2026 00:39:31 +0000 John Groves <[email protected]> wrote:
> From: John Groves <[email protected]> > > The fs_dax_get() function should be called by fs-dax file systems after > opening a fsdev dax device. This adds holder_operations, which provides > a memory failure callback path and effects exclusivity between callers > of fs_dax_get(). > > fs_dax_get() is specific to fsdev_dax, so it checks the driver type > (which required touching bus.[ch]). fs_dax_get() fails if fsdev_dax is > not bound to the memory. > > This function serves the same role as fs_dax_get_by_bdev(), which dax > file systems call after opening the pmem block device. > > This can't be located in fsdev.c because struct dax_device is opaque > there. > > This will be called by fs/fuse/famfs.c in a subsequent commit. > > Signed-off-by: John Groves <[email protected]> Hi John, Looks like a stray header change - see inline. With that tidied up. Reviewed-by: Jonathan Cameron <[email protected]> > #define dax_driver_register(driver) \ > diff --git a/drivers/dax/super.c b/drivers/dax/super.c > index ba0b4cd18a77..d4ab60c406bf 100644 > --- a/drivers/dax/super.c > +++ b/drivers/dax/super.c > diff --git a/include/linux/dax.h b/include/linux/dax.h > index b19bfe0c2fd1..bf37b9a982f3 100644 > --- a/include/linux/dax.h > +++ b/include/linux/dax.h > #if IS_ENABLED(CONFIG_FS_DAX) > +void fs_put_dax(struct dax_device *dax_dev, void *holder); > +int fs_dax_get(struct dax_device *dax_dev, void *holder, > + const struct dax_holder_operations *hops); > +struct dax_device *inode_dax(struct inode *inode); What's this? Not used in this patch and not stubbed. It's in drivers/dax/dax-private.h already and given I assume code builds before this patch (and it's not used in patch 8) then presumably it doesn't need to be here. I got suspicious due to the lack of stub rather indicating something differnt form the other two. > int dax_writeback_mapping_range(struct address_space *mapping, > struct dax_device *dax_dev, struct writeback_control *wbc); > int dax_folio_reset_order(struct folio *folio); > @@ -164,6 +164,15 @@ dax_entry_t dax_lock_mapping_entry(struct address_space > *mapping, > void dax_unlock_mapping_entry(struct address_space *mapping, > unsigned long index, dax_entry_t cookie); > #else > +static inline void fs_put_dax(struct dax_device *dax_dev, void *holder) > +{ > +} > + > +static inline int fs_dax_get(struct dax_device *dax_dev, void *holder, > + const struct dax_holder_operations *hops) > +{ > + return -EOPNOTSUPP; > +} > static inline struct page *dax_layout_busy_page(struct address_space > *mapping) > { > return NULL;
