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authorVishal Verma <vishal.l.verma@intel.com>2016-04-21 15:13:46 -0400
committerVishal Verma <vishal.l.verma@intel.com>2016-05-18 12:16:57 -0600
commit4b0228fa1d753f77fe0e6cf4c41398ec77dfbd2a (patch)
tree323a881d26a983060f82477b8391717fa5b10e9d /fs/dax.c
parent679c8bd3b29428e736eabb7fc66a978f312f0c86 (diff)
downloadlinux-4b0228fa1d753f77fe0e6cf4c41398ec77dfbd2a.tar.bz2
dax: for truncate/hole-punch, do zeroing through the driver if possible
In the truncate or hole-punch path in dax, we clear out sub-page ranges. If these sub-page ranges are sector aligned and sized, we can do the zeroing through the driver instead so that error-clearing is handled automatically. For sub-sector ranges, we still have to rely on clear_pmem and have the possibility of tripping over errors. Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Diffstat (limited to 'fs/dax.c')
-rw-r--r--fs/dax.c30
1 files changed, 25 insertions, 5 deletions
diff --git a/fs/dax.c b/fs/dax.c
index 651d4b18ac29..0b9a16934017 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -947,6 +947,19 @@ int dax_pfn_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
}
EXPORT_SYMBOL_GPL(dax_pfn_mkwrite);
+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, sector_t sector,
unsigned int offset, unsigned int length)
{
@@ -955,11 +968,18 @@ int __dax_zero_page_range(struct block_device *bdev, sector_t sector,
.size = PAGE_SIZE,
};
- if (dax_map_atomic(bdev, &dax) < 0)
- return PTR_ERR(dax.addr);
- clear_pmem(dax.addr + offset, length);
- wmb_pmem();
- dax_unmap_atomic(bdev, &dax);
+ if (dax_range_is_aligned(bdev, offset, length)) {
+ sector_t start_sector = dax.sector + (offset >> 9);
+
+ return blkdev_issue_zeroout(bdev, start_sector,
+ length >> 9, GFP_NOFS, true);
+ } else {
+ if (dax_map_atomic(bdev, &dax) < 0)
+ return PTR_ERR(dax.addr);
+ clear_pmem(dax.addr + offset, length);
+ wmb_pmem();
+ dax_unmap_atomic(bdev, &dax);
+ }
return 0;
}
EXPORT_SYMBOL_GPL(__dax_zero_page_range);