Messages in this thread | | | Subject | Re: [PATCH v2 2/5] ext4: call dax_get_unmapped_area() for DAX pmd mappings | From | Toshi Kani <> | Date | Wed, 13 Apr 2016 09:08:36 -0600 |
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On Tue, 2016-04-12 at 23:01 -0400, Matthew Wilcox wrote: > On Tue, Apr 12, 2016 at 02:39:29PM -0600, Toshi Kani wrote: > > > > To support DAX pmd mappings with unmodified applications, > > filesystems need to align an mmap address by the pmd size. > > > > @@ -708,6 +708,9 @@ const struct file_operations ext4_file_operations = > > { > > .open = ext4_file_open, > > .release = ext4_release_file, > > .fsync = ext4_sync_file, > > +#ifdef CONFIG_FS_DAX > > + .get_unmapped_area = dax_get_unmapped_area, > > +#endif > > .splice_read = generic_file_splice_read, > > .splice_write = iter_file_splice_write, > > .fallocate = ext4_fallocate, > > Could you do something like: > > #ifdef CONFIG_FS_DAX > struct page *read_dax_sector(struct block_device *bdev, sector_t n); > +unsigned long dax_get_unmapped_area(struct file *filp, unsigned long > addr, > + unsigned long len, unsigned long pgoff, unsigned long > flags); > #else > static inline struct page *read_dax_sector(struct block_device *bdev, > sector_t n) > { > return ERR_PTR(-ENXIO); > } > +#define dax_get_unmapped_area NULL > #endif > > in patch 1/5. Then there's no need for the ifdefs in each filesystem.
I thought about it, but I do not think we can use an inline function to an entry point.
Thanks, -Toshi
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