diff mbox series

[v5,3/7] fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero

Message ID 20210511030933.3080921-4-ruansy.fnst@fujitsu.com (mailing list archive)
State New
Headers show
Series fsdax,xfs: Add reflink&dedupe support for fsdax | expand

Commit Message

ruansy.fnst@fujitsu.com May 11, 2021, 3:09 a.m. UTC
Punch hole on a reflinked file needs dax_copy_edge() too.  Otherwise,
data in not aligned area will be not correct.  So, add the srcmap to
dax_iomap_zero() and replace memset() as dax_copy_edge().

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
---
 fs/dax.c               | 25 +++++++++++++++----------
 fs/iomap/buffered-io.c |  2 +-
 include/linux/dax.h    |  3 ++-
 3 files changed, 18 insertions(+), 12 deletions(-)

Comments

Darrick J. Wong May 12, 2021, 1:17 a.m. UTC | #1
On Tue, May 11, 2021 at 11:09:29AM +0800, Shiyang Ruan wrote:
> Punch hole on a reflinked file needs dax_copy_edge() too.  Otherwise,
> data in not aligned area will be not correct.  So, add the srcmap to
> dax_iomap_zero() and replace memset() as dax_copy_edge().
> 
> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
> ---
>  fs/dax.c               | 25 +++++++++++++++----------
>  fs/iomap/buffered-io.c |  2 +-
>  include/linux/dax.h    |  3 ++-
>  3 files changed, 18 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index ef0e564e7904..ee9d28a79bfb 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1186,7 +1186,8 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf,
>  }
>  #endif /* CONFIG_FS_DAX_PMD */
>  
> -s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
> +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
> +		struct iomap *srcmap)
>  {
>  	sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
>  	pgoff_t pgoff;
> @@ -1208,19 +1209,23 @@ s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
>  
>  	if (page_aligned)
>  		rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
> -	else
> +	else {
>  		rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
> -	if (rc < 0) {
> -		dax_read_unlock(id);
> -		return rc;
> -	}
> -
> -	if (!page_aligned) {
> -		memset(kaddr + offset, 0, size);
> +		if (rc < 0)
> +			goto out;
> +		if (iomap->addr != srcmap->addr) {

Why isn't this "if (srcmap->type != IOMAP_HOLE)" ?

I suppose it has the same effect, since @iomap should never be a hole
and we should never have a @srcmap that's the same as @iomap, but
still, we use IOMAP_HOLE checks in most other parts of fs/iomap/.

Other than that, the logic looks decent to me.

--D

> +			rc = dax_iomap_cow_copy(offset, size, PAGE_SIZE, srcmap,
> +						kaddr);
> +			if (rc < 0)
> +				goto out;
> +		} else
> +			memset(kaddr + offset, 0, size);
>  		dax_flush(iomap->dax_dev, kaddr + offset, size);
>  	}
> +
> +out:
>  	dax_read_unlock(id);
> -	return size;
> +	return rc < 0 ? rc : size;
>  }
>  
>  static loff_t
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index f2cd2034a87b..2734955ea67f 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -933,7 +933,7 @@ static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,
>  		s64 bytes;
>  
>  		if (IS_DAX(inode))
> -			bytes = dax_iomap_zero(pos, length, iomap);
> +			bytes = dax_iomap_zero(pos, length, iomap, srcmap);
>  		else
>  			bytes = iomap_zero(inode, pos, length, iomap, srcmap);
>  		if (bytes < 0)
> diff --git a/include/linux/dax.h b/include/linux/dax.h
> index b52f084aa643..3275e01ed33d 100644
> --- a/include/linux/dax.h
> +++ b/include/linux/dax.h
> @@ -237,7 +237,8 @@ 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);
> -s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap);
> +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
> +		struct iomap *srcmap);
>  static inline bool dax_mapping(struct address_space *mapping)
>  {
>  	return mapping->host && IS_DAX(mapping->host);
> -- 
> 2.31.1
> 
> 
>
ruansy.fnst@fujitsu.com May 12, 2021, 1:37 a.m. UTC | #2
> -----Original Message-----
> From: Darrick J. Wong <djwong@kernel.org>
> Subject: Re: [PATCH v5 3/7] fsdax: Add dax_iomap_cow_copy() for
> dax_iomap_zero
> 
> On Tue, May 11, 2021 at 11:09:29AM +0800, Shiyang Ruan wrote:
> > Punch hole on a reflinked file needs dax_copy_edge() too.  Otherwise,
> > data in not aligned area will be not correct.  So, add the srcmap to
> > dax_iomap_zero() and replace memset() as dax_copy_edge().
> >
> > Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> > Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
> > ---
> >  fs/dax.c               | 25 +++++++++++++++----------
> >  fs/iomap/buffered-io.c |  2 +-
> >  include/linux/dax.h    |  3 ++-
> >  3 files changed, 18 insertions(+), 12 deletions(-)
> >
> > diff --git a/fs/dax.c b/fs/dax.c
> > index ef0e564e7904..ee9d28a79bfb 100644
> > --- a/fs/dax.c
> > +++ b/fs/dax.c
> > @@ -1186,7 +1186,8 @@ static vm_fault_t dax_pmd_load_hole(struct
> > xa_state *xas, struct vm_fault *vmf,  }  #endif /* CONFIG_FS_DAX_PMD
> > */
> >
> > -s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
> > +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
> > +		struct iomap *srcmap)
> >  {
> >  	sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
> >  	pgoff_t pgoff;
> > @@ -1208,19 +1209,23 @@ s64 dax_iomap_zero(loff_t pos, u64 length,
> > struct iomap *iomap)
> >
> >  	if (page_aligned)
> >  		rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
> > -	else
> > +	else {
> >  		rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
> > -	if (rc < 0) {
> > -		dax_read_unlock(id);
> > -		return rc;
> > -	}
> > -
> > -	if (!page_aligned) {
> > -		memset(kaddr + offset, 0, size);
> > +		if (rc < 0)
> > +			goto out;
> > +		if (iomap->addr != srcmap->addr) {
> 
> Why isn't this "if (srcmap->type != IOMAP_HOLE)" ?
> 
> I suppose it has the same effect, since @iomap should never be a hole and we
> should never have a @srcmap that's the same as @iomap, but still, we use
> IOMAP_HOLE checks in most other parts of fs/iomap/.

According to its caller `iomap_zero_range_actor()`, whether srcmap->type is IOMAP_HOLE has already been checked before `dax_iomap_zero()`.  So the check you suggested will always be true...


--
Thanks,
Ruan Shiyang.

> 
> Other than that, the logic looks decent to me.
> 
> --D
> 
> > +			rc = dax_iomap_cow_copy(offset, size, PAGE_SIZE, srcmap,
> > +						kaddr);
> > +			if (rc < 0)
> > +				goto out;
> > +		} else
> > +			memset(kaddr + offset, 0, size);
> >  		dax_flush(iomap->dax_dev, kaddr + offset, size);
> >  	}
> > +
> > +out:
> >  	dax_read_unlock(id);
> > -	return size;
> > +	return rc < 0 ? rc : size;
> >  }
> >
> >  static loff_t
> > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index
> > f2cd2034a87b..2734955ea67f 100644
> > --- a/fs/iomap/buffered-io.c
> > +++ b/fs/iomap/buffered-io.c
> > @@ -933,7 +933,7 @@ static loff_t iomap_zero_range_actor(struct inode
> *inode, loff_t pos,
> >  		s64 bytes;
> >
> >  		if (IS_DAX(inode))
> > -			bytes = dax_iomap_zero(pos, length, iomap);
> > +			bytes = dax_iomap_zero(pos, length, iomap, srcmap);
> >  		else
> >  			bytes = iomap_zero(inode, pos, length, iomap, srcmap);
> >  		if (bytes < 0)
> > diff --git a/include/linux/dax.h b/include/linux/dax.h index
> > b52f084aa643..3275e01ed33d 100644
> > --- a/include/linux/dax.h
> > +++ b/include/linux/dax.h
> > @@ -237,7 +237,8 @@ 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);
> > -s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap);
> > +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
> > +		struct iomap *srcmap);
> >  static inline bool dax_mapping(struct address_space *mapping)  {
> >  	return mapping->host && IS_DAX(mapping->host);
> > --
> > 2.31.1
> >
> >
> >
>
Mika Penttilä May 12, 2021, 2:27 a.m. UTC | #3
Hi,

On 11.5.2021 6.09, Shiyang Ruan wrote:
> Punch hole on a reflinked file needs dax_copy_edge() too.  Otherwise,
> data in not aligned area will be not correct.  So, add the srcmap to
> dax_iomap_zero() and replace memset() as dax_copy_edge().
>
> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
> ---
>   fs/dax.c               | 25 +++++++++++++++----------
>   fs/iomap/buffered-io.c |  2 +-
>   include/linux/dax.h    |  3 ++-
>   3 files changed, 18 insertions(+), 12 deletions(-)
>
> diff --git a/fs/dax.c b/fs/dax.c
> index ef0e564e7904..ee9d28a79bfb 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1186,7 +1186,8 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf,
>   }
>   #endif /* CONFIG_FS_DAX_PMD */
>   
> -s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
> +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
> +		struct iomap *srcmap)
>   {
>   	sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
>   	pgoff_t pgoff;
> @@ -1208,19 +1209,23 @@ s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
>   
>   	if (page_aligned)
>   		rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
> -	else
> +	else {
>   		rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
> -	if (rc < 0) {
> -		dax_read_unlock(id);
> -		return rc;
> -	}
> -
> -	if (!page_aligned) {
> -		memset(kaddr + offset, 0, size);
> +		if (rc < 0)
> +			goto out;
> +		if (iomap->addr != srcmap->addr) {
> +			rc = dax_iomap_cow_copy(offset, size, PAGE_SIZE, srcmap,
> +						kaddr);

offset above is offset in page, think dax_iomap_cow_copy() expects 
absolute pos

> +			if (rc < 0)
> +				goto out;
> +		} else
> +			memset(kaddr + offset, 0, size);
>   		dax_flush(iomap->dax_dev, kaddr + offset, size);
>   	}
> +
> +out:
>   	dax_read_unlock(id);
> -	return size;
> +	return rc < 0 ? rc : size;
>   }
>   
>   static loff_t
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index f2cd2034a87b..2734955ea67f 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -933,7 +933,7 @@ static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,
>   		s64 bytes;
>   
>   		if (IS_DAX(inode))
> -			bytes = dax_iomap_zero(pos, length, iomap);
> +			bytes = dax_iomap_zero(pos, length, iomap, srcmap);
>   		else
>   			bytes = iomap_zero(inode, pos, length, iomap, srcmap);
>   		if (bytes < 0)
> diff --git a/include/linux/dax.h b/include/linux/dax.h
> index b52f084aa643..3275e01ed33d 100644
> --- a/include/linux/dax.h
> +++ b/include/linux/dax.h
> @@ -237,7 +237,8 @@ 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);
> -s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap);
> +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
> +		struct iomap *srcmap);
>   static inline bool dax_mapping(struct address_space *mapping)
>   {
>   	return mapping->host && IS_DAX(mapping->host);
ruansy.fnst@fujitsu.com May 13, 2021, 7:48 a.m. UTC | #4
> -----Original Message-----
> From: Mika Penttilä <mika.penttila@nextfour.com>
> Subject: Re: [PATCH v5 3/7] fsdax: Add dax_iomap_cow_copy() for
> dax_iomap_zero
> 
> Hi,
> 
> On 11.5.2021 6.09, Shiyang Ruan wrote:
> > Punch hole on a reflinked file needs dax_copy_edge() too.  Otherwise,
> > data in not aligned area will be not correct.  So, add the srcmap to
> > dax_iomap_zero() and replace memset() as dax_copy_edge().
> >
> > Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> > Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
> > ---
> >   fs/dax.c               | 25 +++++++++++++++----------
> >   fs/iomap/buffered-io.c |  2 +-
> >   include/linux/dax.h    |  3 ++-
> >   3 files changed, 18 insertions(+), 12 deletions(-)
> >
> > diff --git a/fs/dax.c b/fs/dax.c
> > index ef0e564e7904..ee9d28a79bfb 100644
> > --- a/fs/dax.c
> > +++ b/fs/dax.c
> > @@ -1186,7 +1186,8 @@ static vm_fault_t dax_pmd_load_hole(struct
> xa_state *xas, struct vm_fault *vmf,
> >   }
> >   #endif /* CONFIG_FS_DAX_PMD */
> >
> > -s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
> > +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
> > +		struct iomap *srcmap)
> >   {
> >   	sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
> >   	pgoff_t pgoff;
> > @@ -1208,19 +1209,23 @@ s64 dax_iomap_zero(loff_t pos, u64 length,
> > struct iomap *iomap)
> >
> >   	if (page_aligned)
> >   		rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
> > -	else
> > +	else {
> >   		rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
> > -	if (rc < 0) {
> > -		dax_read_unlock(id);
> > -		return rc;
> > -	}
> > -
> > -	if (!page_aligned) {
> > -		memset(kaddr + offset, 0, size);
> > +		if (rc < 0)
> > +			goto out;
> > +		if (iomap->addr != srcmap->addr) {
> > +			rc = dax_iomap_cow_copy(offset, size, PAGE_SIZE, srcmap,
> > +						kaddr);
> 
> offset above is offset in page, think dax_iomap_cow_copy() expects absolute pos

You are right.  Should pass pos here.  Thanks for pointing out.


--
Thanks,
Ruan Shiyang.

> 
> > +			if (rc < 0)
> > +				goto out;
> > +		} else
> > +			memset(kaddr + offset, 0, size);
> >   		dax_flush(iomap->dax_dev, kaddr + offset, size);
> >   	}
> > +
> > +out:
> >   	dax_read_unlock(id);
> > -	return size;
> > +	return rc < 0 ? rc : size;
> >   }
> >
> >   static loff_t
> > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index
> > f2cd2034a87b..2734955ea67f 100644
> > --- a/fs/iomap/buffered-io.c
> > +++ b/fs/iomap/buffered-io.c
> > @@ -933,7 +933,7 @@ static loff_t iomap_zero_range_actor(struct inode
> *inode, loff_t pos,
> >   		s64 bytes;
> >
> >   		if (IS_DAX(inode))
> > -			bytes = dax_iomap_zero(pos, length, iomap);
> > +			bytes = dax_iomap_zero(pos, length, iomap, srcmap);
> >   		else
> >   			bytes = iomap_zero(inode, pos, length, iomap, srcmap);
> >   		if (bytes < 0)
> > diff --git a/include/linux/dax.h b/include/linux/dax.h index
> > b52f084aa643..3275e01ed33d 100644
> > --- a/include/linux/dax.h
> > +++ b/include/linux/dax.h
> > @@ -237,7 +237,8 @@ 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);
> > -s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap);
> > +s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
> > +		struct iomap *srcmap);
> >   static inline bool dax_mapping(struct address_space *mapping)
> >   {
> >   	return mapping->host && IS_DAX(mapping->host);
diff mbox series

Patch

diff --git a/fs/dax.c b/fs/dax.c
index ef0e564e7904..ee9d28a79bfb 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1186,7 +1186,8 @@  static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf,
 }
 #endif /* CONFIG_FS_DAX_PMD */
 
-s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
+s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
+		struct iomap *srcmap)
 {
 	sector_t sector = iomap_sector(iomap, pos & PAGE_MASK);
 	pgoff_t pgoff;
@@ -1208,19 +1209,23 @@  s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap)
 
 	if (page_aligned)
 		rc = dax_zero_page_range(iomap->dax_dev, pgoff, 1);
-	else
+	else {
 		rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
-	if (rc < 0) {
-		dax_read_unlock(id);
-		return rc;
-	}
-
-	if (!page_aligned) {
-		memset(kaddr + offset, 0, size);
+		if (rc < 0)
+			goto out;
+		if (iomap->addr != srcmap->addr) {
+			rc = dax_iomap_cow_copy(offset, size, PAGE_SIZE, srcmap,
+						kaddr);
+			if (rc < 0)
+				goto out;
+		} else
+			memset(kaddr + offset, 0, size);
 		dax_flush(iomap->dax_dev, kaddr + offset, size);
 	}
+
+out:
 	dax_read_unlock(id);
-	return size;
+	return rc < 0 ? rc : size;
 }
 
 static loff_t
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index f2cd2034a87b..2734955ea67f 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -933,7 +933,7 @@  static loff_t iomap_zero_range_actor(struct inode *inode, loff_t pos,
 		s64 bytes;
 
 		if (IS_DAX(inode))
-			bytes = dax_iomap_zero(pos, length, iomap);
+			bytes = dax_iomap_zero(pos, length, iomap, srcmap);
 		else
 			bytes = iomap_zero(inode, pos, length, iomap, srcmap);
 		if (bytes < 0)
diff --git a/include/linux/dax.h b/include/linux/dax.h
index b52f084aa643..3275e01ed33d 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -237,7 +237,8 @@  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);
-s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap);
+s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap,
+		struct iomap *srcmap);
 static inline bool dax_mapping(struct address_space *mapping)
 {
 	return mapping->host && IS_DAX(mapping->host);