diff mbox series

[v2,9/9] iomap: Change calling convention for zeroing

Message ID 20200910234707.5504-10-willy@infradead.org (mailing list archive)
State Accepted
Commit 81ee8e52a71c712dbe04994f1430cb4c88b87ad6
Headers show
Series THP iomap patches for 5.10 | expand

Commit Message

Matthew Wilcox Sept. 10, 2020, 11:47 p.m. UTC 
Pass the full length to iomap_zero() and dax_iomap_zero(), and have
them return how many bytes they actually handled.  This is preparatory
work for handling THP, although it looks like DAX could actually take
advantage of it if there's a larger contiguous area.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/dax.c               | 13 ++++++-------
 fs/iomap/buffered-io.c | 33 +++++++++++++++------------------
 include/linux/dax.h    |  3 +--
 3 files changed, 22 insertions(+), 27 deletions(-)

Comments

Christoph Hellwig Sept. 11, 2020, 6:42 a.m. UTC | #1 
On Fri, Sep 11, 2020 at 12:47:07AM +0100, Matthew Wilcox (Oracle) wrote:
> Pass the full length to iomap_zero() and dax_iomap_zero(), and have
> them return how many bytes they actually handled.  This is preparatory
> work for handling THP, although it looks like DAX could actually take
> advantage of it if there's a larger contiguous area.

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
Darrick J. Wong Sept. 17, 2020, 10:05 p.m. UTC | #2 
On Fri, Sep 11, 2020 at 12:47:07AM +0100, Matthew Wilcox (Oracle) wrote:
> Pass the full length to iomap_zero() and dax_iomap_zero(), and have
> them return how many bytes they actually handled.  This is preparatory
> work for handling THP, although it looks like DAX could actually take
> advantage of it if there's a larger contiguous area.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  fs/dax.c               | 13 ++++++-------
>  fs/iomap/buffered-io.c | 33 +++++++++++++++------------------
>  include/linux/dax.h    |  3 +--
>  3 files changed, 22 insertions(+), 27 deletions(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index 994ab66a9907..6ad346352a8c 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1037,18 +1037,18 @@ static vm_fault_t dax_load_hole(struct xa_state *xas,
>  	return ret;
>  }
>  
> -int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
> -		   struct iomap *iomap)
> +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
>  {
>  	sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
>  	pgoff_t pgoff;
>  	long rc, id;
>  	void *kaddr;
>  	bool page_aligned = false;
> -
> +	unsigned offset = offset_in_page(pos);
> +	unsigned size = min_t(u64, PAGE_SIZE - offset, length);
>  
>  	if (IS_ALIGNED(sector << SECTOR_SHIFT, PAGE_SIZE) &&
> -	    IS_ALIGNED(size, PAGE_SIZE))
> +	    (size == PAGE_SIZE))
>  		page_aligned = true;
>  
>  	rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
> @@ -1058,8 +1058,7 @@ int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
>  	id = dax_read_lock();
>  
>  	if (page_aligned)
> -		rc = dax_zero_page_range(iomap->dax_dev, pgoff,
> -					 size >> PAGE_SHIFT);
> +		rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
>  	else
>  		rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
>  	if (rc < 0) {
> @@ -1072,7 +1071,7 @@ int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
>  		dax_flush(iomap->dax_dev, kaddr + offset, size);
>  	}
>  	dax_read_unlock(id);
> -	return 0;
> +	return size;
>  }
>  
>  static loff_t
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index cb25a7b70401..3e1eb40a73fd 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -898,11 +898,13 @@ iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,
>  }
>  EXPORT_SYMBOL_GPL(iomap_file_unshare);
>  
> -static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
> -		unsigned bytes, struct iomap *iomap, struct iomap *srcmap)
> +static s64 iomap_zero(struct inode *inode, loff_t pos, u64 length,
> +		struct iomap *iomap, struct iomap *srcmap)
>  {
>  	struct page *page;
>  	int status;
> +	unsigned offset = offset_in_page(pos);
> +	unsigned bytes = min_t(u64, PAGE_SIZE - offset, length);
>  
>  	status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap, srcmap);
>  	if (status)
> @@ -914,38 +916,33 @@ static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
>  	return iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap);
>  }
>  
> -static loff_t
> -iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
> -		void *data, struct iomap *iomap, struct iomap *srcmap)
> +static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,
> +		loff_t length, void *data, struct iomap *iomap,

Any reason not to change @length and the return value to s64?

--D

> +		struct iomap *srcmap)
>  {
>  	bool *did_zero = data;
>  	loff_t written = 0;
> -	int status;
>  
>  	/* already zeroed?  we're done. */
>  	if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN)
> -		return count;
> +		return length;
>  
>  	do {
> -		unsigned offset, bytes;
> -
> -		offset = offset_in_page(pos);
> -		bytes = min_t(loff_t, PAGE_SIZE - offset, count);
> +		s64 bytes;
>  
>  		if (IS_DAX(inode))
> -			status = dax_iomap_zero(pos, offset, bytes, iomap);
> +			bytes = dax_iomap_zero(pos, length, iomap);
>  		else
> -			status = iomap_zero(inode, pos, offset, bytes, iomap,
> -					srcmap);
> -		if (status < 0)
> -			return status;
> +			bytes = iomap_zero(inode, pos, length, iomap, srcmap);
> +		if (bytes < 0)
> +			return bytes;
>  
>  		pos += bytes;
> -		count -= bytes;
> +		length -= bytes;
>  		written += bytes;
>  		if (did_zero)
>  			*did_zero = true;
> -	} while (count > 0);
> +	} while (length > 0);
>  
>  	return written;
>  }
> diff --git a/include/linux/dax.h b/include/linux/dax.h
> index 6904d4e0b2e0..951a851a0481 100644
> --- a/include/linux/dax.h
> +++ b/include/linux/dax.h
> @@ -214,8 +214,7 @@ vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
>  int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
>  int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
>  				      pgoff_t index);
> -int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
> -			struct iomap *iomap);
> +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap);
>  static inline bool dax_mapping(struct address_space *mapping)
>  {
>  	return mapping->host && IS_DAX(mapping->host);
> -- 
> 2.28.0
>
Matthew Wilcox Sept. 17, 2020, 10:11 p.m. UTC | #3 
On Thu, Sep 17, 2020 at 03:05:00PM -0700, Darrick J. Wong wrote:
> > -static loff_t
> > -iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
> > -		void *data, struct iomap *iomap, struct iomap *srcmap)
> > +static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,
> > +		loff_t length, void *data, struct iomap *iomap,
> 
> Any reason not to change @length and the return value to s64?

Because it's an actor, passed to iomap_apply, so its types have to match.
I can change that, but it'll be a separate patch series.
Darrick J. Wong Sept. 17, 2020, 10:18 p.m. UTC | #4 
On Thu, Sep 17, 2020 at 11:11:15PM +0100, Matthew Wilcox wrote:
> On Thu, Sep 17, 2020 at 03:05:00PM -0700, Darrick J. Wong wrote:
> > > -static loff_t
> > > -iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
> > > -		void *data, struct iomap *iomap, struct iomap *srcmap)
> > > +static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,
> > > +		loff_t length, void *data, struct iomap *iomap,
> > 
> > Any reason not to change @length and the return value to s64?
> 
> Because it's an actor, passed to iomap_apply, so its types have to match.
> I can change that, but it'll be a separate patch series.

Ah, right.  I seemingly forgot that. :(

Carry on.
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D
diff mbox series

Patch

diff --git a/fs/dax.c b/fs/dax.c
index 994ab66a9907..6ad346352a8c 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1037,18 +1037,18 @@  static vm_fault_t dax_load_hole(struct xa_state *xas,
 	return ret;
 }
 
-int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
-		   struct iomap *iomap)
+s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
 {
 	sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
 	pgoff_t pgoff;
 	long rc, id;
 	void *kaddr;
 	bool page_aligned = false;
-
+	unsigned offset = offset_in_page(pos);
+	unsigned size = min_t(u64, PAGE_SIZE - offset, length);
 
 	if (IS_ALIGNED(sector << SECTOR_SHIFT, PAGE_SIZE) &&
-	    IS_ALIGNED(size, PAGE_SIZE))
+	    (size == PAGE_SIZE))
 		page_aligned = true;
 
 	rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
@@ -1058,8 +1058,7 @@  int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
 	id = dax_read_lock();
 
 	if (page_aligned)
-		rc = dax_zero_page_range(iomap->dax_dev, pgoff,
-					 size >> PAGE_SHIFT);
+		rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
 	else
 		rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
 	if (rc < 0) {
@@ -1072,7 +1071,7 @@  int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
 		dax_flush(iomap->dax_dev, kaddr + offset, size);
 	}
 	dax_read_unlock(id);
-	return 0;
+	return size;
 }
 
 static loff_t
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index cb25a7b70401..3e1eb40a73fd 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -898,11 +898,13 @@  iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,
 }
 EXPORT_SYMBOL_GPL(iomap_file_unshare);
 
-static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
-		unsigned bytes, struct iomap *iomap, struct iomap *srcmap)
+static s64 iomap_zero(struct inode *inode, loff_t pos, u64 length,
+		struct iomap *iomap, struct iomap *srcmap)
 {
 	struct page *page;
 	int status;
+	unsigned offset = offset_in_page(pos);
+	unsigned bytes = min_t(u64, PAGE_SIZE - offset, length);
 
 	status = iomap_write_begin(inode, pos, bytes, 0, &page, iomap, srcmap);
 	if (status)
@@ -914,38 +916,33 @@  static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
 	return iomap_write_end(inode, pos, bytes, bytes, page, iomap, srcmap);
 }
 
-static loff_t
-iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count,
-		void *data, struct iomap *iomap, struct iomap *srcmap)
+static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,
+		loff_t length, void *data, struct iomap *iomap,
+		struct iomap *srcmap)
 {
 	bool *did_zero = data;
 	loff_t written = 0;
-	int status;
 
 	/* already zeroed?  we're done. */
 	if (srcmap->type == IOMAP_HOLE || srcmap->type == IOMAP_UNWRITTEN)
-		return count;
+		return length;
 
 	do {
-		unsigned offset, bytes;
-
-		offset = offset_in_page(pos);
-		bytes = min_t(loff_t, PAGE_SIZE - offset, count);
+		s64 bytes;
 
 		if (IS_DAX(inode))
-			status = dax_iomap_zero(pos, offset, bytes, iomap);
+			bytes = dax_iomap_zero(pos, length, iomap);
 		else
-			status = iomap_zero(inode, pos, offset, bytes, iomap,
-					srcmap);
-		if (status < 0)
-			return status;
+			bytes = iomap_zero(inode, pos, length, iomap, srcmap);
+		if (bytes < 0)
+			return bytes;
 
 		pos += bytes;
-		count -= bytes;
+		length -= bytes;
 		written += bytes;
 		if (did_zero)
 			*did_zero = true;
-	} while (count > 0);
+	} while (length > 0);
 
 	return written;
 }
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 6904d4e0b2e0..951a851a0481 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -214,8 +214,7 @@  vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
 int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
 int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
 				      pgoff_t index);
-int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
-			struct iomap *iomap);
+s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap);
 static inline bool dax_mapping(struct address_space *mapping)
 {
 	return mapping->host && IS_DAX(mapping->host);