[PATCH] xfs: only reclaim unwritten COW extents periodically

[PATCH] xfs: only reclaim unwritten COW extents periodically

[Christoph Hellwig]

We only want to reclaim preallocations from our periodic work item.
Currenrly this is archived by looking for a diry inode, but that check
is rather fragile.  Instead add flags to the xfs_reflink_cancel_cow_* so
that the caller can ask for just cancelling unwritten extents in the COw
fork.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_aops.c    |  2 +-
 fs/xfs/xfs_icache.c  |  2 +-
 fs/xfs/xfs_inode.c   |  2 +-
 fs/xfs/xfs_reflink.c | 14 +++++++++-----
 fs/xfs/xfs_reflink.h |  5 +++--
 fs/xfs/xfs_super.c   |  2 +-
 6 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index b480647e00e7..290c0fb306e7 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -293,7 +293,7 @@ xfs_end_io(
 			goto done;
 		if (ioend->io_bio->bi_error) {
 			error = xfs_reflink_cancel_cow_range(ip,
-					ioend->io_offset, ioend->io_size);
+					ioend->io_offset, ioend->io_size, 0);
 			goto done;
 		}
 		error = xfs_reflink_end_cow(ip, ioend->io_offset,
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 7234b9748c36..1f7d158266c1 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1608,7 +1608,7 @@ xfs_inode_free_cowblocks(
 	xfs_ilock(ip, XFS_IOLOCK_EXCL);
 	xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
 
-	ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
+	ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, XFS_CC_UNWRITTEN);
 
 	xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
 	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index edfa6a55b064..164e74a511b1 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1615,7 +1615,7 @@ xfs_itruncate_extents(
 
 	/* Remove all pending CoW reservations. */
 	error = xfs_reflink_cancel_cow_blocks(ip, &tp, first_unmap_block,
-			last_block);
+			last_block, 0);
 	if (error)
 		goto out;
 
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 08ca9f81b087..83605af3b135 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -551,7 +551,8 @@ xfs_reflink_cancel_cow_blocks(
 	struct xfs_inode		*ip,
 	struct xfs_trans		**tpp,
 	xfs_fileoff_t			offset_fsb,
-	xfs_fileoff_t			end_fsb)
+	xfs_fileoff_t			end_fsb,
+	unsigned			flags)
 {
 	struct xfs_ifork		*ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
 	struct xfs_bmbt_irec		got, del;
@@ -575,7 +576,8 @@ xfs_reflink_cancel_cow_blocks(
 					&idx, &got, &del);
 			if (error)
 				break;
-		} else {
+		} else if (del.br_state == XFS_EXT_UNWRITTEN ||
+			   !(flags & XFS_CC_UNWRITTEN)) {
 			xfs_trans_ijoin(*tpp, ip, 0);
 			xfs_defer_init(&dfops, &firstfsb);
 
@@ -623,7 +625,8 @@ int
 xfs_reflink_cancel_cow_range(
 	struct xfs_inode	*ip,
 	xfs_off_t		offset,
-	xfs_off_t		count)
+	xfs_off_t		count,
+	unsigned		flags)
 {
 	struct xfs_trans	*tp;
 	xfs_fileoff_t		offset_fsb;
@@ -649,7 +652,8 @@ xfs_reflink_cancel_cow_range(
 	xfs_trans_ijoin(tp, ip, 0);
 
 	/* Scrape out the old CoW reservations */
-	error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb);
+	error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb,
+			flags);
 	if (error)
 		goto out_cancel;
 
@@ -1437,7 +1441,7 @@ xfs_reflink_clear_inode_flag(
 	 * We didn't find any shared blocks so turn off the reflink flag.
 	 * First, get rid of any leftover CoW mappings.
 	 */
-	error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF);
+	error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF, 0);
 	if (error)
 		return error;
 
diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
index 33ac9b8db683..9416279b3c89 100644
--- a/fs/xfs/xfs_reflink.h
+++ b/fs/xfs/xfs_reflink.h
@@ -37,11 +37,12 @@ extern bool xfs_reflink_find_cow_mapping(struct xfs_inode *ip, xfs_off_t offset,
 extern void xfs_reflink_trim_irec_to_next_cow(struct xfs_inode *ip,
 		xfs_fileoff_t offset_fsb, struct xfs_bmbt_irec *imap);
 
+#define XFS_CC_UNWRITTEN	0x01
 extern int xfs_reflink_cancel_cow_blocks(struct xfs_inode *ip,
 		struct xfs_trans **tpp, xfs_fileoff_t offset_fsb,
-		xfs_fileoff_t end_fsb);
+		xfs_fileoff_t end_fsb, unsigned flags);
 extern int xfs_reflink_cancel_cow_range(struct xfs_inode *ip, xfs_off_t offset,
-		xfs_off_t count);
+		xfs_off_t count, unsigned flags);
 extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset,
 		xfs_off_t count);
 extern int xfs_reflink_recover_cow(struct xfs_mount *mp);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 890862f2447c..9136854030d5 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -953,7 +953,7 @@ xfs_fs_destroy_inode(
 	XFS_STATS_INC(ip->i_mount, vn_remove);
 
 	if (xfs_is_reflink_inode(ip)) {
-		error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
+		error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, 0);
 		if (error && !XFS_FORCED_SHUTDOWN(ip->i_mount))
 			xfs_warn(ip->i_mount,
 "Error %d while evicting CoW blocks for inode %llu.",
-- 
2.11.0

Re: [PATCH] xfs: only reclaim unwritten COW extents periodically

[Darrick J. Wong]

On Mon, Feb 27, 2017 at 04:49:10PM -0800, Christoph Hellwig wrote:
> We only want to reclaim preallocations from our periodic work item.
> Currenrly this is archived by looking for a diry inode, but that check
> is rather fragile.  Instead add flags to the xfs_reflink_cancel_cow_* so
> that the caller can ask for just cancelling unwritten extents in the COw
> fork.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/xfs/xfs_aops.c    |  2 +-
>  fs/xfs/xfs_icache.c  |  2 +-
>  fs/xfs/xfs_inode.c   |  2 +-
>  fs/xfs/xfs_reflink.c | 14 +++++++++-----
>  fs/xfs/xfs_reflink.h |  5 +++--
>  fs/xfs/xfs_super.c   |  2 +-
>  6 files changed, 16 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> index b480647e00e7..290c0fb306e7 100644
> --- a/fs/xfs/xfs_aops.c
> +++ b/fs/xfs/xfs_aops.c
> @@ -293,7 +293,7 @@ xfs_end_io(
>  			goto done;
>  		if (ioend->io_bio->bi_error) {
>  			error = xfs_reflink_cancel_cow_range(ip,
> -					ioend->io_offset, ioend->io_size);
> +					ioend->io_offset, ioend->io_size, 0);
>  			goto done;
>  		}
>  		error = xfs_reflink_end_cow(ip, ioend->io_offset,
> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index 7234b9748c36..1f7d158266c1 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
> @@ -1608,7 +1608,7 @@ xfs_inode_free_cowblocks(
>  	xfs_ilock(ip, XFS_IOLOCK_EXCL);
>  	xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
>  
> -	ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
> +	ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, XFS_CC_UNWRITTEN);

Ok, so the periodic work item leaves real cow extents alone now, which
is good since real extents now represent pending cow operations.  Good.

>  	xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
>  	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index edfa6a55b064..164e74a511b1 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -1615,7 +1615,7 @@ xfs_itruncate_extents(
>  
>  	/* Remove all pending CoW reservations. */
>  	error = xfs_reflink_cancel_cow_blocks(ip, &tp, first_unmap_block,
> -			last_block);
> +			last_block, 0);
>  	if (error)
>  		goto out;
>  
> diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> index 08ca9f81b087..83605af3b135 100644
> --- a/fs/xfs/xfs_reflink.c
> +++ b/fs/xfs/xfs_reflink.c
> @@ -551,7 +551,8 @@ xfs_reflink_cancel_cow_blocks(
>  	struct xfs_inode		*ip,
>  	struct xfs_trans		**tpp,
>  	xfs_fileoff_t			offset_fsb,
> -	xfs_fileoff_t			end_fsb)
> +	xfs_fileoff_t			end_fsb,
> +	unsigned			flags)
>  {
>  	struct xfs_ifork		*ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
>  	struct xfs_bmbt_irec		got, del;
> @@ -575,7 +576,8 @@ xfs_reflink_cancel_cow_blocks(
>  					&idx, &got, &del);
>  			if (error)
>  				break;
> -		} else {
> +		} else if (del.br_state == XFS_EXT_UNWRITTEN ||
> +			   !(flags & XFS_CC_UNWRITTEN)) {
>  			xfs_trans_ijoin(*tpp, ip, 0);
>  			xfs_defer_init(&dfops, &firstfsb);
>  
> @@ -623,7 +625,8 @@ int
>  xfs_reflink_cancel_cow_range(
>  	struct xfs_inode	*ip,
>  	xfs_off_t		offset,
> -	xfs_off_t		count)
> +	xfs_off_t		count,
> +	unsigned		flags)
>  {
>  	struct xfs_trans	*tp;
>  	xfs_fileoff_t		offset_fsb;
> @@ -649,7 +652,8 @@ xfs_reflink_cancel_cow_range(
>  	xfs_trans_ijoin(tp, ip, 0);
>  
>  	/* Scrape out the old CoW reservations */
> -	error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb);
> +	error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb,
> +			flags);
>  	if (error)
>  		goto out_cancel;
>  
> @@ -1437,7 +1441,7 @@ xfs_reflink_clear_inode_flag(
>  	 * We didn't find any shared blocks so turn off the reflink flag.
>  	 * First, get rid of any leftover CoW mappings.
>  	 */
> -	error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF);
> +	error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF, 0);
>  	if (error)
>  		return error;
>  
> diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
> index 33ac9b8db683..9416279b3c89 100644
> --- a/fs/xfs/xfs_reflink.h
> +++ b/fs/xfs/xfs_reflink.h
> @@ -37,11 +37,12 @@ extern bool xfs_reflink_find_cow_mapping(struct xfs_inode *ip, xfs_off_t offset,
>  extern void xfs_reflink_trim_irec_to_next_cow(struct xfs_inode *ip,
>  		xfs_fileoff_t offset_fsb, struct xfs_bmbt_irec *imap);
>  
> +#define XFS_CC_UNWRITTEN	0x01

Could we have a comment here about what CC_UNWRITTEN means?

I /think/ it means "don't remove real extents", since when it's specified
delalloc reservations still get removed by _reflink_cancel_cow_*, correct?

Somewhere we ought to record the fact that flags == 0 removes everything.

--D

>  extern int xfs_reflink_cancel_cow_blocks(struct xfs_inode *ip,
>  		struct xfs_trans **tpp, xfs_fileoff_t offset_fsb,
> -		xfs_fileoff_t end_fsb);
> +		xfs_fileoff_t end_fsb, unsigned flags);
>  extern int xfs_reflink_cancel_cow_range(struct xfs_inode *ip, xfs_off_t offset,
> -		xfs_off_t count);
> +		xfs_off_t count, unsigned flags);
>  extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset,
>  		xfs_off_t count);
>  extern int xfs_reflink_recover_cow(struct xfs_mount *mp);
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 890862f2447c..9136854030d5 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -953,7 +953,7 @@ xfs_fs_destroy_inode(
>  	XFS_STATS_INC(ip->i_mount, vn_remove);
>  
>  	if (xfs_is_reflink_inode(ip)) {
> -		error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
> +		error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, 0);
>  		if (error && !XFS_FORCED_SHUTDOWN(ip->i_mount))
>  			xfs_warn(ip->i_mount,
>  "Error %d while evicting CoW blocks for inode %llu.",
> -- 
> 2.11.0
> 
> --
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> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] xfs: only reclaim unwritten COW extents periodically

[Darrick J. Wong]

On Mon, Feb 27, 2017 at 09:26:51PM -0800, Darrick J. Wong wrote:
> On Mon, Feb 27, 2017 at 04:49:10PM -0800, Christoph Hellwig wrote:
> > We only want to reclaim preallocations from our periodic work item.
> > Currenrly this is archived by looking for a diry inode, but that check
> > is rather fragile.  Instead add flags to the xfs_reflink_cancel_cow_* so
> > that the caller can ask for just cancelling unwritten extents in the COw
> > fork.
> > 
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > ---
> >  fs/xfs/xfs_aops.c    |  2 +-
> >  fs/xfs/xfs_icache.c  |  2 +-
> >  fs/xfs/xfs_inode.c   |  2 +-
> >  fs/xfs/xfs_reflink.c | 14 +++++++++-----
> >  fs/xfs/xfs_reflink.h |  5 +++--
> >  fs/xfs/xfs_super.c   |  2 +-
> >  6 files changed, 16 insertions(+), 11 deletions(-)
> > 
> > diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> > index b480647e00e7..290c0fb306e7 100644
> > --- a/fs/xfs/xfs_aops.c
> > +++ b/fs/xfs/xfs_aops.c
> > @@ -293,7 +293,7 @@ xfs_end_io(
> >  			goto done;
> >  		if (ioend->io_bio->bi_error) {
> >  			error = xfs_reflink_cancel_cow_range(ip,
> > -					ioend->io_offset, ioend->io_size);
> > +					ioend->io_offset, ioend->io_size, 0);
> >  			goto done;
> >  		}
> >  		error = xfs_reflink_end_cow(ip, ioend->io_offset,
> > diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> > index 7234b9748c36..1f7d158266c1 100644
> > --- a/fs/xfs/xfs_icache.c
> > +++ b/fs/xfs/xfs_icache.c
> > @@ -1608,7 +1608,7 @@ xfs_inode_free_cowblocks(
> >  	xfs_ilock(ip, XFS_IOLOCK_EXCL);
> >  	xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
> >  
> > -	ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
> > +	ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, XFS_CC_UNWRITTEN);
> 
> Ok, so the periodic work item leaves real cow extents alone now, which
> is good since real extents now represent pending cow operations.  Good.
> 
> >  	xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
> >  	xfs_iunlock(ip, XFS_IOLOCK_EXCL);
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> > index edfa6a55b064..164e74a511b1 100644
> > --- a/fs/xfs/xfs_inode.c
> > +++ b/fs/xfs/xfs_inode.c
> > @@ -1615,7 +1615,7 @@ xfs_itruncate_extents(
> >  
> >  	/* Remove all pending CoW reservations. */
> >  	error = xfs_reflink_cancel_cow_blocks(ip, &tp, first_unmap_block,
> > -			last_block);
> > +			last_block, 0);
> >  	if (error)
> >  		goto out;
> >  
> > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> > index 08ca9f81b087..83605af3b135 100644
> > --- a/fs/xfs/xfs_reflink.c
> > +++ b/fs/xfs/xfs_reflink.c
> > @@ -551,7 +551,8 @@ xfs_reflink_cancel_cow_blocks(
> >  	struct xfs_inode		*ip,
> >  	struct xfs_trans		**tpp,
> >  	xfs_fileoff_t			offset_fsb,
> > -	xfs_fileoff_t			end_fsb)
> > +	xfs_fileoff_t			end_fsb,
> > +	unsigned			flags)
> >  {
> >  	struct xfs_ifork		*ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
> >  	struct xfs_bmbt_irec		got, del;
> > @@ -575,7 +576,8 @@ xfs_reflink_cancel_cow_blocks(
> >  					&idx, &got, &del);
> >  			if (error)
> >  				break;
> > -		} else {
> > +		} else if (del.br_state == XFS_EXT_UNWRITTEN ||
> > +			   !(flags & XFS_CC_UNWRITTEN)) {
> >  			xfs_trans_ijoin(*tpp, ip, 0);
> >  			xfs_defer_init(&dfops, &firstfsb);
> >  
> > @@ -623,7 +625,8 @@ int
> >  xfs_reflink_cancel_cow_range(
> >  	struct xfs_inode	*ip,
> >  	xfs_off_t		offset,
> > -	xfs_off_t		count)
> > +	xfs_off_t		count,
> > +	unsigned		flags)
> >  {
> >  	struct xfs_trans	*tp;
> >  	xfs_fileoff_t		offset_fsb;
> > @@ -649,7 +652,8 @@ xfs_reflink_cancel_cow_range(
> >  	xfs_trans_ijoin(tp, ip, 0);
> >  
> >  	/* Scrape out the old CoW reservations */
> > -	error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb);
> > +	error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb,
> > +			flags);
> >  	if (error)
> >  		goto out_cancel;
> >  
> > @@ -1437,7 +1441,7 @@ xfs_reflink_clear_inode_flag(
> >  	 * We didn't find any shared blocks so turn off the reflink flag.
> >  	 * First, get rid of any leftover CoW mappings.
> >  	 */
> > -	error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF);
> > +	error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF, 0);
> >  	if (error)
> >  		return error;
> >  
> > diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
> > index 33ac9b8db683..9416279b3c89 100644
> > --- a/fs/xfs/xfs_reflink.h
> > +++ b/fs/xfs/xfs_reflink.h
> > @@ -37,11 +37,12 @@ extern bool xfs_reflink_find_cow_mapping(struct xfs_inode *ip, xfs_off_t offset,
> >  extern void xfs_reflink_trim_irec_to_next_cow(struct xfs_inode *ip,
> >  		xfs_fileoff_t offset_fsb, struct xfs_bmbt_irec *imap);
> >  
> > +#define XFS_CC_UNWRITTEN	0x01
> 
> Could we have a comment here about what CC_UNWRITTEN means?
> 
> I /think/ it means "don't remove real extents", since when it's specified
> delalloc reservations still get removed by _reflink_cancel_cow_*, correct?
> 
> Somewhere we ought to record the fact that flags == 0 removes everything.

It's been a week; ping?  (Or: did anyone receive this reply at all?)

--D

> 
> --D
> 
> >  extern int xfs_reflink_cancel_cow_blocks(struct xfs_inode *ip,
> >  		struct xfs_trans **tpp, xfs_fileoff_t offset_fsb,
> > -		xfs_fileoff_t end_fsb);
> > +		xfs_fileoff_t end_fsb, unsigned flags);
> >  extern int xfs_reflink_cancel_cow_range(struct xfs_inode *ip, xfs_off_t offset,
> > -		xfs_off_t count);
> > +		xfs_off_t count, unsigned flags);
> >  extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset,
> >  		xfs_off_t count);
> >  extern int xfs_reflink_recover_cow(struct xfs_mount *mp);
> > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> > index 890862f2447c..9136854030d5 100644
> > --- a/fs/xfs/xfs_super.c
> > +++ b/fs/xfs/xfs_super.c
> > @@ -953,7 +953,7 @@ xfs_fs_destroy_inode(
> >  	XFS_STATS_INC(ip->i_mount, vn_remove);
> >  
> >  	if (xfs_is_reflink_inode(ip)) {
> > -		error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
> > +		error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, 0);
> >  		if (error && !XFS_FORCED_SHUTDOWN(ip->i_mount))
> >  			xfs_warn(ip->i_mount,
> >  "Error %d while evicting CoW blocks for inode %llu.",
> > -- 
> > 2.11.0
> > 
> > --
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Re: [PATCH] xfs: only reclaim unwritten COW extents periodically

[Christoph Hellwig]

On Mon, Mar 06, 2017 at 04:17:02PM -0800, Darrick J. Wong wrote:
> > Could we have a comment here about what CC_UNWRITTEN means?
> > 
> > I /think/ it means "don't remove real extents", since when it's specified
> > delalloc reservations still get removed by _reflink_cancel_cow_*, correct?
> > 
> > Somewhere we ought to record the fact that flags == 0 removes everything.
> 
> It's been a week; ping?  (Or: did anyone receive this reply at all?)

I've been travelling and fairly busy.  But I'll try to prepare a new
version ASAP, especially as this something that should go into 4.11,
unlike the rest of the series.