[PATCH] ext4: Fix ext4_bmap to flush the data to the disk with delalloc

[PATCH] ext4: Fix ext4_bmap to flush the data to the disk with delalloc

[Aneesh Kumar K.V]

With delalloc we don't do block allocation in the write_begin/write_end.
So when using bmap we first need to flush data to the disk so that blocks
get allocated and then call generic_block_bmap.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 fs/ext4/inode.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 7035621..cfeb869 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1833,6 +1833,17 @@ sector_t ext4_bmap(struct address_space *mapping, sector_t block)
 	journal_t *journal;
 	int err;
 
+	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
+			test_opt(inode->i_sb, DELALLOC)) {
+		/*
+		 * With delalloc we want to sync the file
+		 * so that we can make sure we allocate
+		 * blocks for file
+		 */
+		filemap_fdatawrite(mapping);
+		filemap_fdatawait(mapping);
+	}
+
 	if (EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
 		/*
 		 * This is a REALLY heavyweight approach, but the use of
-- 
1.5.6.rc2.15.g457bb.dirty

Re: [PATCH] ext4: Fix ext4_bmap to flush the data to the disk with delalloc

[Eric Sandeen]

Aneesh Kumar K.V wrote:
> With delalloc we don't do block allocation in the write_begin/write_end.
> So when using bmap we first need to flush data to the disk so that blocks
> get allocated and then call generic_block_bmap.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
>  fs/ext4/inode.c |   11 +++++++++++
>  1 files changed, 11 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 7035621..cfeb869 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -1833,6 +1833,17 @@ sector_t ext4_bmap(struct address_space *mapping, sector_t block)
>  	journal_t *journal;
>  	int err;
>  
> +	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
> +			test_opt(inode->i_sb, DELALLOC)) {
> +		/*
> +		 * With delalloc we want to sync the file
> +		 * so that we can make sure we allocate
> +		 * blocks for file
> +		 */
> +		filemap_fdatawrite(mapping);
> +		filemap_fdatawait(mapping);
> +	}

This seems fine.

I wonder, does it make any sense at all to only do the flushing if the
block we wish to map is actually in a delalloc state at the moment?

-Eric

> +
>  	if (EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
>  		/*
>  		 * This is a REALLY heavyweight approach, but the use of

Re: [PATCH] ext4: Fix ext4_bmap to flush the data to the disk with delalloc

[Aneesh Kumar K.V]

On Wed, Jun 18, 2008 at 01:03:32PM -0500, Eric Sandeen wrote:
> Aneesh Kumar K.V wrote:
> > With delalloc we don't do block allocation in the write_begin/write_end.
> > So when using bmap we first need to flush data to the disk so that blocks
> > get allocated and then call generic_block_bmap.
> > 
> > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> > ---
> >  fs/ext4/inode.c |   11 +++++++++++
> >  1 files changed, 11 insertions(+), 0 deletions(-)
> > 
> > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> > index 7035621..cfeb869 100644
> > --- a/fs/ext4/inode.c
> > +++ b/fs/ext4/inode.c
> > @@ -1833,6 +1833,17 @@ sector_t ext4_bmap(struct address_space *mapping, sector_t block)
> >  	journal_t *journal;
> >  	int err;
> >  
> > +	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
> > +			test_opt(inode->i_sb, DELALLOC)) {
> > +		/*
> > +		 * With delalloc we want to sync the file
> > +		 * so that we can make sure we allocate
> > +		 * blocks for file
> > +		 */
> > +		filemap_fdatawrite(mapping);
> > +		filemap_fdatawait(mapping);
> > +	}
> 
> This seems fine.
> 
> I wonder, does it make any sense at all to only do the flushing if the
> block we wish to map is actually in a delalloc state at the moment?
> 

I am not sure it is worth the complexity considering bmap is not a
frequently used API. Initially I was even thinking should i be doing
it only for delalloc. That test seems to be a simple one to put.

-aneesh

Re: [PATCH] ext4: Fix ext4_bmap to flush the data to the disk with delalloc

[Mingming]

On Wed, 2008-06-18 at 23:22 +0530, Aneesh Kumar K.V wrote:
> With delalloc we don't do block allocation in the write_begin/write_end.
> So when using bmap we first need to flush data to the disk so that blocks
> get allocated and then call generic_block_bmap.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
>  fs/ext4/inode.c |   11 +++++++++++
>  1 files changed, 11 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 7035621..cfeb869 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -1833,6 +1833,17 @@ sector_t ext4_bmap(struct address_space *mapping, sector_t block)
>  	journal_t *journal;
>  	int err;
> 
> +	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
> +			test_opt(inode->i_sb, DELALLOC)) {
> +		/*
> +		 * With delalloc we want to sync the file
> +		 * so that we can make sure we allocate
> +		 * blocks for file
> +		 */
> +		filemap_fdatawrite(mapping);
> +		filemap_fdatawait(mapping);
> +	}
> +

I would use filemap_write_and_wait(), it is essentially the same as
above two functions, but with a little extra checking.

Mingming
>  	if (EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
>  		/*
>  		 * This is a REALLY heavyweight approach, but the use of

Re: [PATCH] ext4: Fix ext4_bmap to flush the data to the disk with delalloc

[Aneesh Kumar K.V]

On Wed, Jun 18, 2008 at 03:26:25PM -0700, Mingming wrote:
> 
> On Wed, 2008-06-18 at 23:22 +0530, Aneesh Kumar K.V wrote:
> > With delalloc we don't do block allocation in the write_begin/write_end.
> > So when using bmap we first need to flush data to the disk so that blocks
> > get allocated and then call generic_block_bmap.
> > 
> > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> > ---
> >  fs/ext4/inode.c |   11 +++++++++++
> >  1 files changed, 11 insertions(+), 0 deletions(-)
> > 
> > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> > index 7035621..cfeb869 100644
> > --- a/fs/ext4/inode.c
> > +++ b/fs/ext4/inode.c
> > @@ -1833,6 +1833,17 @@ sector_t ext4_bmap(struct address_space *mapping, sector_t block)
> >  	journal_t *journal;
> >  	int err;
> > 
> > +	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
> > +			test_opt(inode->i_sb, DELALLOC)) {
> > +		/*
> > +		 * With delalloc we want to sync the file
> > +		 * so that we can make sure we allocate
> > +		 * blocks for file
> > +		 */
> > +		filemap_fdatawrite(mapping);
> > +		filemap_fdatawait(mapping);
> > +	}
> > +
> 
> I would use filemap_write_and_wait(), it is essentially the same as
> above two functions, but with a little extra checking.
> 

Updated patch below

ext4: Fix ext4_bmap to flush the data to the disk with delalloc

From: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

With delalloc we don't do block allocation in the write_begin/write_end.
So when using bmap we first need to flush data to the disk so that blocks
get allocated and then call generic_block_bmap.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---

 fs/ext4/inode.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)


diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 7035621..f1bd194 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1833,6 +1833,16 @@ sector_t ext4_bmap(struct address_space *mapping, sector_t block)
 	journal_t *journal;
 	int err;
 
+	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
+			test_opt(inode->i_sb, DELALLOC)) {
+		/*
+		 * With delalloc we want to sync the file
+		 * so that we can make sure we allocate
+		 * blocks for file
+		 */
+		filemap_write_and_wait(mapping);
+	}
+
 	if (EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
 		/*
 		 * This is a REALLY heavyweight approach, but the use of