fsdax: simplify the pgoff calculation

Replace the two steps of dax_iomap_sector and bdev_dax_pgoff with a
single dax_iomap_pgoff helper that avoids lots of cumbersome sector
conversions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20211129102203.2243509-15-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 90b5733..45d931a 100644 (file)
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -66,20 +66,6 @@ void dax_remove_host(struct gendisk *disk)
 }
 EXPORT_SYMBOL_GPL(dax_remove_host);
 
-int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size,
-               pgoff_t *pgoff)
-{
-       sector_t start_sect = bdev ? get_start_sect(bdev) : 0;
-       phys_addr_t phys_off = (start_sect + sector) * 512;
-
-       if (pgoff)
-               *pgoff = PHYS_PFN(phys_off);
-       if (phys_off % PAGE_SIZE || size % PAGE_SIZE)
-               return -EINVAL;
-       return 0;
-}
-EXPORT_SYMBOL(bdev_dax_pgoff);
-
 /**
  * fs_dax_get_by_bdev() - temporary lookup mechanism for filesystem-dax
  * @bdev: block device to find a dax_device for

diff --git a/fs/dax.c b/fs/dax.c
index e51b412..5364549 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -709,23 +709,22 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
        return __dax_invalidate_entry(mapping, index, false);
 }
 
-static sector_t dax_iomap_sector(const struct iomap *iomap, loff_t pos)
+static pgoff_t dax_iomap_pgoff(const struct iomap *iomap, loff_t pos)
 {
-       return (iomap->addr + (pos & PAGE_MASK) - iomap->offset) >> 9;
+       phys_addr_t paddr = iomap->addr + (pos & PAGE_MASK) - iomap->offset;
+
+       if (iomap->bdev)
+               paddr += (get_start_sect(iomap->bdev) << SECTOR_SHIFT);
+       return PHYS_PFN(paddr);
 }
 
 static int copy_cow_page_dax(struct vm_fault *vmf, const struct iomap_iter *iter)
 {
-       sector_t sector = dax_iomap_sector(&iter->iomap, iter->pos);
+       pgoff_t pgoff = dax_iomap_pgoff(&iter->iomap, iter->pos);
        void *vto, *kaddr;
-       pgoff_t pgoff;
        long rc;
        int id;
 
-       rc = bdev_dax_pgoff(iter->iomap.bdev, sector, PAGE_SIZE, &pgoff);
-       if (rc)
-               return rc;
-
        id = dax_read_lock();
        rc = dax_direct_access(iter->iomap.dax_dev, pgoff, 1, &kaddr, NULL);
        if (rc < 0) {
@@ -1013,14 +1012,10 @@ EXPORT_SYMBOL_GPL(dax_writeback_mapping_range);
 static int dax_iomap_pfn(const struct iomap *iomap, loff_t pos, size_t size,
                         pfn_t *pfnp)
 {
-       const sector_t sector = dax_iomap_sector(iomap, pos);
-       pgoff_t pgoff;
+       pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);
        int id, rc;
        long length;
 
-       rc = bdev_dax_pgoff(iomap->bdev, sector, size, &pgoff);
-       if (rc)
-               return rc;
        id = dax_read_lock();
        length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size),
                                   NULL, pfnp);
@@ -1129,7 +1124,7 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf,
 s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
 {
        sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
-       pgoff_t pgoff;
+       pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);
        long rc, id;
        void *kaddr;
        bool page_aligned = false;
@@ -1140,10 +1135,6 @@ s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
            (size == PAGE_SIZE))
                page_aligned = true;
 
-       rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
-       if (rc)
-               return rc;
-
        id = dax_read_lock();
 
        if (page_aligned)
@@ -1169,7 +1160,6 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
        const struct iomap *iomap = &iomi->iomap;
        loff_t length = iomap_length(iomi);
        loff_t pos = iomi->pos;
-       struct block_device *bdev = iomap->bdev;
        struct dax_device *dax_dev = iomap->dax_dev;
        loff_t end = pos + length, done = 0;
        ssize_t ret = 0;
@@ -1203,9 +1193,8 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
        while (pos < end) {
                unsigned offset = pos & (PAGE_SIZE - 1);
                const size_t size = ALIGN(length + offset, PAGE_SIZE);
-               const sector_t sector = dax_iomap_sector(iomap, pos);
+               pgoff_t pgoff = dax_iomap_pgoff(iomap, pos);
                ssize_t map_len;
-               pgoff_t pgoff;
                void *kaddr;
 
                if (fatal_signal_pending(current)) {
@@ -1213,10 +1202,6 @@ static loff_t dax_iomap_iter(const struct iomap_iter *iomi,
                        break;
                }
 
-               ret = bdev_dax_pgoff(bdev, sector, size, &pgoff);
-               if (ret)
-                       break;
-
                map_len = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size),
                                &kaddr, NULL);
                if (map_len < 0) {

diff --git a/include/linux/dax.h b/include/linux/dax.h
index 439c3c7..324363b 100644 (file)
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -107,7 +107,6 @@ static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
 #endif
 
 struct writeback_control;
-int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
 #if IS_ENABLED(CONFIG_FS_DAX)
 int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk);
 void dax_remove_host(struct gendisk *disk);