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author | Vivek Goyal <vgoyal@redhat.com> | 2020-02-28 11:34:55 -0500 |
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committer | Dan Williams <dan.j.williams@intel.com> | 2020-04-02 19:15:03 -0700 |
commit | 0a23f9ffa5ac20d3c95a6e850f4ee68e4034f781 (patch) | |
tree | 60d1e8e0819b3fb1c58ef8992794e1ba526873f0 /fs/dax.c | |
parent | cdf6cdcd3b99a99ea9ecc1b05d1d040d5a69a134 (diff) | |
download | lwn-0a23f9ffa5ac20d3c95a6e850f4ee68e4034f781.tar.gz lwn-0a23f9ffa5ac20d3c95a6e850f4ee68e4034f781.zip |
dax: Use new dax zero page method for zeroing a page
Use new dax native zero page method for zeroing page if I/O is page
aligned. Otherwise fall back to direct_access() + memcpy().
This gets rid of one of the depenendency on block device in dax path.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Link: https://lore.kernel.org/r/20200228163456.1587-6-vgoyal@redhat.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'fs/dax.c')
-rw-r--r-- | fs/dax.c | 53 |
1 files changed, 23 insertions, 30 deletions
@@ -1038,47 +1038,40 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, return ret; } -static bool dax_range_is_aligned(struct block_device *bdev, - unsigned int offset, unsigned int length) -{ - unsigned short sector_size = bdev_logical_block_size(bdev); - - if (!IS_ALIGNED(offset, sector_size)) - return false; - if (!IS_ALIGNED(length, sector_size)) - return false; - - return true; -} - int __dax_zero_page_range(struct block_device *bdev, struct dax_device *dax_dev, sector_t sector, unsigned int offset, unsigned int size) { - if (dax_range_is_aligned(bdev, offset, size)) { - sector_t start_sector = sector + (offset >> 9); + pgoff_t pgoff; + long rc, id; + void *kaddr; + bool page_aligned = false; - return blkdev_issue_zeroout(bdev, start_sector, - size >> 9, GFP_NOFS, 0); - } else { - pgoff_t pgoff; - long rc, id; - void *kaddr; - rc = bdev_dax_pgoff(bdev, sector, PAGE_SIZE, &pgoff); - if (rc) - return rc; + if (IS_ALIGNED(sector << SECTOR_SHIFT, PAGE_SIZE) && + IS_ALIGNED(size, PAGE_SIZE)) + page_aligned = true; + + rc = bdev_dax_pgoff(bdev, sector, PAGE_SIZE, &pgoff); + if (rc) + return rc; - id = dax_read_lock(); + id = dax_read_lock(); + + if (page_aligned) + rc = dax_zero_page_range(dax_dev, pgoff, size >> PAGE_SHIFT); + else rc = dax_direct_access(dax_dev, pgoff, 1, &kaddr, NULL); - if (rc < 0) { - dax_read_unlock(id); - return rc; - } + if (rc < 0) { + dax_read_unlock(id); + return rc; + } + + if (!page_aligned) { memset(kaddr + offset, 0, size); dax_flush(dax_dev, kaddr + offset, size); - dax_read_unlock(id); } + dax_read_unlock(id); return 0; } EXPORT_SYMBOL_GPL(__dax_zero_page_range); |