[14/18] dax: memcpy before zeroing range
diff mbox series

Message ID 20190429172649.8288-15-rgoldwyn@suse.de
State New
Headers show
Series
  • btrfs dax support
Related show

Commit Message

Goldwyn Rodrigues April 29, 2019, 5:26 p.m. UTC
From: Goldwyn Rodrigues <rgoldwyn@suse.com>

However, this needed more iomap fields, so it was easier
to pass iomap and compute inside the function rather
than passing a log of arguments.

Note, there is subtle difference between iomap_sector and
dax_iomap_sector(). Can we replace dax_iomap_sector with
iomap_sector()? It would need pos & PAGE_MASK though or else
bdev_dax_pgoff() return -EINVAL.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
 fs/dax.c              | 17 ++++++++++++-----
 fs/iomap.c            |  9 +--------
 include/linux/dax.h   | 11 +++++------
 include/linux/iomap.h |  6 ++++++
 4 files changed, 24 insertions(+), 19 deletions(-)

Comments

Darrick J. Wong May 21, 2019, 5:27 p.m. UTC | #1
On Mon, Apr 29, 2019 at 12:26:45PM -0500, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> However, this needed more iomap fields, so it was easier
> to pass iomap and compute inside the function rather
> than passing a log of arguments.
> 
> Note, there is subtle difference between iomap_sector and
> dax_iomap_sector(). Can we replace dax_iomap_sector with
> iomap_sector()? It would need pos & PAGE_MASK though or else
> bdev_dax_pgoff() return -EINVAL.
> 
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
> ---
>  fs/dax.c              | 17 ++++++++++++-----
>  fs/iomap.c            |  9 +--------
>  include/linux/dax.h   | 11 +++++------
>  include/linux/iomap.h |  6 ++++++
>  4 files changed, 24 insertions(+), 19 deletions(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index fa9ccbad7c03..82a08b0eec23 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1063,11 +1063,16 @@ static bool dax_range_is_aligned(struct block_device *bdev,
>  	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)
> +int __dax_zero_page_range(struct iomap *iomap, loff_t pos,
> +			  unsigned int offset, unsigned int size)
>  {
> -	if (dax_range_is_aligned(bdev, offset, size)) {
> +	sector_t sector = dax_iomap_sector(iomap, pos & PAGE_MASK);
> +	struct block_device *bdev = iomap->bdev;
> +	struct dax_device *dax_dev = iomap->dax_dev;
> +	int ret = 0;
> +
> +	if (!(iomap->type == IOMAP_DAX_COW) &&
> +	    dax_range_is_aligned(bdev, offset, size)) {
>  		sector_t start_sector = sector + (offset >> 9);
>  
>  		return blkdev_issue_zeroout(bdev, start_sector,
> @@ -1087,11 +1092,13 @@ int __dax_zero_page_range(struct block_device *bdev,
>  			dax_read_unlock(id);
>  			return rc;
>  		}
> +		if (iomap->type == IOMAP_DAX_COW)
> +			ret = memcpy_mcsafe(kaddr, iomap->inline_data, offset);

If the memcpy fails, does it make sense to keep going?

>  		memset(kaddr + offset, 0, size);

Is it ever the case that offset + size isn't the end of the page?  If
so, then don't we need a second memcpy_mcsafe to handle that too?

>  		dax_flush(dax_dev, kaddr + offset, size);
>  		dax_read_unlock(id);
>  	}
> -	return 0;
> +	return ret;
>  }
>  EXPORT_SYMBOL_GPL(__dax_zero_page_range);
>  
> diff --git a/fs/iomap.c b/fs/iomap.c
> index abdd18e404f8..90698c854883 100644
> --- a/fs/iomap.c
> +++ b/fs/iomap.c
> @@ -98,12 +98,6 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags,
>  	return written ? written : ret;
>  }
>  
> -static sector_t
> -iomap_sector(struct iomap *iomap, loff_t pos)
> -{
> -	return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;
> -}
> -
>  static struct iomap_page *
>  iomap_page_create(struct inode *inode, struct page *page)
>  {
> @@ -990,8 +984,7 @@ static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
>  static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes,
>  		struct iomap *iomap)
>  {
> -	return __dax_zero_page_range(iomap->bdev, iomap->dax_dev,
> -			iomap_sector(iomap, pos & PAGE_MASK), offset, bytes);
> +	return __dax_zero_page_range(iomap, pos, offset, bytes);
>  }
>  
>  static loff_t
> diff --git a/include/linux/dax.h b/include/linux/dax.h
> index 1370d39c91b6..c469d9ff54b4 100644
> --- a/include/linux/dax.h
> +++ b/include/linux/dax.h
> @@ -9,6 +9,7 @@
>  
>  typedef unsigned long dax_entry_t;
>  
> +struct iomap;
>  struct iomap_ops;
>  struct dax_device;
>  struct dax_operations {
> @@ -163,13 +164,11 @@ int dax_file_range_compare(struct inode *src, loff_t srcoff,
>  			   const struct iomap_ops *ops);
>  
>  #ifdef CONFIG_FS_DAX
> -int __dax_zero_page_range(struct block_device *bdev,
> -		struct dax_device *dax_dev, sector_t sector,
> -		unsigned int offset, unsigned int length);
> +int __dax_zero_page_range(struct iomap *iomap, loff_t pos,
> +		unsigned int offset, unsigned int size);
>  #else
> -static inline int __dax_zero_page_range(struct block_device *bdev,
> -		struct dax_device *dax_dev, sector_t sector,
> -		unsigned int offset, unsigned int length)
> +static inline int __dax_zero_page_range(struct iomap *iomap, loff_t pos,
> +		unsigned int offset, unsigned int size)
>  {
>  	return -ENXIO;
>  }
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 6e885c5a38a3..fcfce269db3e 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -7,6 +7,7 @@
>  #include <linux/mm.h>
>  #include <linux/types.h>
>  #include <linux/mm_types.h>
> +#include <linux/blkdev.h>
>  
>  struct address_space;
>  struct fiemap_extent_info;
> @@ -120,6 +121,11 @@ static inline struct iomap_page *to_iomap_page(struct page *page)
>  	return NULL;
>  }
>  
> +static inline sector_t iomap_sector(struct iomap *iomap, loff_t pos)
> +{
> +	return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;
> +}

FWIW the iomap changes seem fine to me.

--D

> +
>  ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
>  		const struct iomap_ops *ops);
>  int iomap_readpage(struct page *page, const struct iomap_ops *ops);
> -- 
> 2.16.4
>

Patch
diff mbox series

diff --git a/fs/dax.c b/fs/dax.c
index fa9ccbad7c03..82a08b0eec23 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1063,11 +1063,16 @@  static bool dax_range_is_aligned(struct block_device *bdev,
 	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)
+int __dax_zero_page_range(struct iomap *iomap, loff_t pos,
+			  unsigned int offset, unsigned int size)
 {
-	if (dax_range_is_aligned(bdev, offset, size)) {
+	sector_t sector = dax_iomap_sector(iomap, pos & PAGE_MASK);
+	struct block_device *bdev = iomap->bdev;
+	struct dax_device *dax_dev = iomap->dax_dev;
+	int ret = 0;
+
+	if (!(iomap->type == IOMAP_DAX_COW) &&
+	    dax_range_is_aligned(bdev, offset, size)) {
 		sector_t start_sector = sector + (offset >> 9);
 
 		return blkdev_issue_zeroout(bdev, start_sector,
@@ -1087,11 +1092,13 @@  int __dax_zero_page_range(struct block_device *bdev,
 			dax_read_unlock(id);
 			return rc;
 		}
+		if (iomap->type == IOMAP_DAX_COW)
+			ret = memcpy_mcsafe(kaddr, iomap->inline_data, offset);
 		memset(kaddr + offset, 0, size);
 		dax_flush(dax_dev, kaddr + offset, size);
 		dax_read_unlock(id);
 	}
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(__dax_zero_page_range);
 
diff --git a/fs/iomap.c b/fs/iomap.c
index abdd18e404f8..90698c854883 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -98,12 +98,6 @@  iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags,
 	return written ? written : ret;
 }
 
-static sector_t
-iomap_sector(struct iomap *iomap, loff_t pos)
-{
-	return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;
-}
-
 static struct iomap_page *
 iomap_page_create(struct inode *inode, struct page *page)
 {
@@ -990,8 +984,7 @@  static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
 static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes,
 		struct iomap *iomap)
 {
-	return __dax_zero_page_range(iomap->bdev, iomap->dax_dev,
-			iomap_sector(iomap, pos & PAGE_MASK), offset, bytes);
+	return __dax_zero_page_range(iomap, pos, offset, bytes);
 }
 
 static loff_t
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 1370d39c91b6..c469d9ff54b4 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -9,6 +9,7 @@ 
 
 typedef unsigned long dax_entry_t;
 
+struct iomap;
 struct iomap_ops;
 struct dax_device;
 struct dax_operations {
@@ -163,13 +164,11 @@  int dax_file_range_compare(struct inode *src, loff_t srcoff,
 			   const struct iomap_ops *ops);
 
 #ifdef CONFIG_FS_DAX
-int __dax_zero_page_range(struct block_device *bdev,
-		struct dax_device *dax_dev, sector_t sector,
-		unsigned int offset, unsigned int length);
+int __dax_zero_page_range(struct iomap *iomap, loff_t pos,
+		unsigned int offset, unsigned int size);
 #else
-static inline int __dax_zero_page_range(struct block_device *bdev,
-		struct dax_device *dax_dev, sector_t sector,
-		unsigned int offset, unsigned int length)
+static inline int __dax_zero_page_range(struct iomap *iomap, loff_t pos,
+		unsigned int offset, unsigned int size)
 {
 	return -ENXIO;
 }
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 6e885c5a38a3..fcfce269db3e 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -7,6 +7,7 @@ 
 #include <linux/mm.h>
 #include <linux/types.h>
 #include <linux/mm_types.h>
+#include <linux/blkdev.h>
 
 struct address_space;
 struct fiemap_extent_info;
@@ -120,6 +121,11 @@  static inline struct iomap_page *to_iomap_page(struct page *page)
 	return NULL;
 }
 
+static inline sector_t iomap_sector(struct iomap *iomap, loff_t pos)
+{
+	return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;
+}
+
 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
 		const struct iomap_ops *ops);
 int iomap_readpage(struct page *page, const struct iomap_ops *ops);