linux-next: manual merge of the block tree with the ext4 tree

linux-next: manual merge of the block tree with the ext4 tree

[Stephen Rothwell]

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Hi Jens,

Today's linux-next merge of the block tree got a conflict in
fs/fs-writeback.c between commit ef7fdf5e8c87 ("vfs: add support for a
lazytime mount option") from the ext4 tree and commit 9c6ac78eb352
("writeback: fix a subtle race condition in I_DIRTY clearing") from the
block tree.

I fixed it up (I took a guess, plese check - see below) and can carry
the fix as necessary (no action is required).

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

diff --cc fs/fs-writeback.c
index 3d87174408ae,2d609a5fbfea..000000000000
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@@ -482,14 -479,30 +482,30 @@@ __writeback_single_inode(struct inode *
  	 * write_inode()
  	 */
  	spin_lock(&inode->i_lock);
- 	/* Clear I_DIRTY_PAGES if we've written out all dirty pages */
- 	if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
- 		inode->i_state &= ~I_DIRTY_PAGES;
+ 
 -	dirty = inode->i_state & I_DIRTY;
 -	inode->i_state &= ~I_DIRTY;
 +	dirty = inode->i_state & I_DIRTY_INODE;
 +	inode->i_state &= ~I_DIRTY_INODE;
+ 
+ 	/*
+ 	 * Paired with smp_mb() in __mark_inode_dirty().  This allows
+ 	 * __mark_inode_dirty() to test i_state without grabbing i_lock -
+ 	 * either they see the I_DIRTY bits cleared or we see the dirtied
+ 	 * inode.
+ 	 *
+ 	 * I_DIRTY_PAGES is always cleared together above even if @mapping
+ 	 * still has dirty pages.  The flag is reinstated after smp_mb() if
+ 	 * necessary.  This guarantees that either __mark_inode_dirty()
+ 	 * sees clear I_DIRTY_PAGES or we see PAGECACHE_TAG_DIRTY.
+ 	 */
+ 	smp_mb();
+ 
+ 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
+ 		inode->i_state |= I_DIRTY_PAGES;
+ 
  	spin_unlock(&inode->i_lock);
+ 
  	/* Don't write the inode if only I_DIRTY_PAGES was set */
 -	if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
 +	if (dirty) {
  		int err = write_inode(inode, wbc);
  		if (ret == 0)
  			ret = err;

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Re: linux-next: manual merge of the block tree with the ext4 tree

[Christoph Hellwig]

On Thu, Nov 27, 2014 at 02:53:47PM +1100, Stephen Rothwell wrote:
> Hi Jens,
> 
> Today's linux-next merge of the block tree got a conflict in
> fs/fs-writeback.c between commit ef7fdf5e8c87 ("vfs: add support for a
> lazytime mount option")

Mergign that into a branch for linux-next must surely have been a
mistake, as the code isn't anywhere near ready.

I also think it very much should go into through the vfs tree.

Re: linux-next: manual merge of the block tree with the ext4 tree

[Sabrina Dubroca]

Hello,

[adding Jeremiah Mahler to CC]

2014-11-27, 14:53:47 +1100, Stephen Rothwell wrote:
> Hi Jens,
> 
> Today's linux-next merge of the block tree got a conflict in
> fs/fs-writeback.c between commit ef7fdf5e8c87 ("vfs: add support for a
> lazytime mount option") from the ext4 tree and commit 9c6ac78eb352
> ("writeback: fix a subtle race condition in I_DIRTY clearing") from the
> block tree.
> 
> I fixed it up (I took a guess, plese check - see below) and can carry
> the fix as necessary (no action is required).
> 
> -- 
> Cheers,
> Stephen Rothwell                    sfr@canb.auug.org.au
> 
> diff --cc fs/fs-writeback.c
> index 3d87174408ae,2d609a5fbfea..000000000000
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@@ -482,14 -479,30 +482,30 @@@ __writeback_single_inode(struct inode *
>   	 * write_inode()
>   	 */
>   	spin_lock(&inode->i_lock);
> - 	/* Clear I_DIRTY_PAGES if we've written out all dirty pages */
> - 	if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
> - 		inode->i_state &= ~I_DIRTY_PAGES;
> + 
>  -	dirty = inode->i_state & I_DIRTY;
>  -	inode->i_state &= ~I_DIRTY;
>  +	dirty = inode->i_state & I_DIRTY_INODE;
>  +	inode->i_state &= ~I_DIRTY_INODE;
> + 
> + 	/*
> + 	 * Paired with smp_mb() in __mark_inode_dirty().  This allows
> + 	 * __mark_inode_dirty() to test i_state without grabbing i_lock -
> + 	 * either they see the I_DIRTY bits cleared or we see the dirtied
> + 	 * inode.
> + 	 *
> + 	 * I_DIRTY_PAGES is always cleared together above even if @mapping
> + 	 * still has dirty pages.  The flag is reinstated after smp_mb() if
> + 	 * necessary.  This guarantees that either __mark_inode_dirty()
> + 	 * sees clear I_DIRTY_PAGES or we see PAGECACHE_TAG_DIRTY.
> + 	 */
> + 	smp_mb();
> + 
> + 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
> + 		inode->i_state |= I_DIRTY_PAGES;
> + 
>   	spin_unlock(&inode->i_lock);
> + 
>   	/* Don't write the inode if only I_DIRTY_PAGES was set */
>  -	if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
>  +	if (dirty) {
>   		int err = write_inode(inode, wbc);
>   		if (ret == 0)
>   			ret = err;


I think there's a problem in your fix, Stephen.

I'm getting hangs at boot (strangely -- in QEMU -- only when booting
via grub, not when using -kernel) and during shutdown.  Jeremiah seems
to have the same problem and his bisection led to the merge commit:
https://lkml.org/lkml/2014/11/29/17

The following solves both issues for me.  I think it makes sense given
the #defines from ef7fdf5e8c87, since Tejun intended to clear
I_DIRTY_PAGES.


diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index b70e45f45afa..6b2510d97a0a 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -484,7 +484,7 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
 	spin_lock(&inode->i_lock);
 
 	dirty = inode->i_state & I_DIRTY_INODE;
-	inode->i_state &= ~I_DIRTY_INODE;
+	inode->i_state &= ~I_DIRTY;
 
 	/*
 	 * Paired with smp_mb() in __mark_inode_dirty().  This allows


-- 
Thanks,
Sabrina

Re: linux-next: manual merge of the block tree with the ext4 tree

[Theodore Ts'o]

Note the relevant changes from the ext4 tree were dropped from the
dev branch, so this shouldn't be an issue moving forward.

    	       	    	      	    	  - Ted

Re: linux-next: manual merge of the block tree with the ext4 tree

[Jeremiah Mahler]

Hi,

On Sat, Nov 29, 2014 at 11:08:33AM +0100, Sabrina Dubroca wrote:
> Hello,
> 
> [adding Jeremiah Mahler to CC]
> 
> 2014-11-27, 14:53:47 +1100, Stephen Rothwell wrote:
> > Hi Jens,
> > 
> > Today's linux-next merge of the block tree got a conflict in
> > fs/fs-writeback.c between commit ef7fdf5e8c87 ("vfs: add support for a
> > lazytime mount option") from the ext4 tree and commit 9c6ac78eb352
> > ("writeback: fix a subtle race condition in I_DIRTY clearing") from the
> > block tree.
> > 
> > I fixed it up (I took a guess, plese check - see below) and can carry
> > the fix as necessary (no action is required).
> > 
> > -- 
> > Cheers,
> > Stephen Rothwell                    sfr@canb.auug.org.au
> > 
> > diff --cc fs/fs-writeback.c
> > index 3d87174408ae,2d609a5fbfea..000000000000
> > --- a/fs/fs-writeback.c
> > +++ b/fs/fs-writeback.c
> > @@@ -482,14 -479,30 +482,30 @@@ __writeback_single_inode(struct inode *
> >   	 * write_inode()
> >   	 */
> >   	spin_lock(&inode->i_lock);
> > - 	/* Clear I_DIRTY_PAGES if we've written out all dirty pages */
> > - 	if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
> > - 		inode->i_state &= ~I_DIRTY_PAGES;
> > + 
> >  -	dirty = inode->i_state & I_DIRTY;
> >  -	inode->i_state &= ~I_DIRTY;
> >  +	dirty = inode->i_state & I_DIRTY_INODE;
> >  +	inode->i_state &= ~I_DIRTY_INODE;
> > + 
> > + 	/*
> > + 	 * Paired with smp_mb() in __mark_inode_dirty().  This allows
> > + 	 * __mark_inode_dirty() to test i_state without grabbing i_lock -
> > + 	 * either they see the I_DIRTY bits cleared or we see the dirtied
> > + 	 * inode.
> > + 	 *
> > + 	 * I_DIRTY_PAGES is always cleared together above even if @mapping
> > + 	 * still has dirty pages.  The flag is reinstated after smp_mb() if
> > + 	 * necessary.  This guarantees that either __mark_inode_dirty()
> > + 	 * sees clear I_DIRTY_PAGES or we see PAGECACHE_TAG_DIRTY.
> > + 	 */
> > + 	smp_mb();
> > + 
> > + 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
> > + 		inode->i_state |= I_DIRTY_PAGES;
> > + 
> >   	spin_unlock(&inode->i_lock);
> > + 
> >   	/* Don't write the inode if only I_DIRTY_PAGES was set */
> >  -	if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
> >  +	if (dirty) {
> >   		int err = write_inode(inode, wbc);
> >   		if (ret == 0)
> >   			ret = err;
> 
> 
> I think there's a problem in your fix, Stephen.
> 
> I'm getting hangs at boot (strangely -- in QEMU -- only when booting
> via grub, not when using -kernel) and during shutdown.  Jeremiah seems
> to have the same problem and his bisection led to the merge commit:
> https://lkml.org/lkml/2014/11/29/17
> 
> The following solves both issues for me.  I think it makes sense given
> the #defines from ef7fdf5e8c87, since Tejun intended to clear
> I_DIRTY_PAGES.
> 
> 
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index b70e45f45afa..6b2510d97a0a 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -484,7 +484,7 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
>  	spin_lock(&inode->i_lock);
>  
>  	dirty = inode->i_state & I_DIRTY_INODE;
> -	inode->i_state &= ~I_DIRTY_INODE;
> +	inode->i_state &= ~I_DIRTY;
>  
>  	/*
>  	 * Paired with smp_mb() in __mark_inode_dirty().  This allows
> 
> 
> -- 
> Thanks,
> Sabrina

That change fixes the problem.

Thanks Sabrina and Stephen!

-- 
- Jeremiah Mahler

Re: linux-next: manual merge of the block tree with the ext4 tree

[Stephen Rothwell]

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Hi all,

On Mon, 26 Jun 2023 13:09:51 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> 
> Today's linux-next merge of the block tree got a conflict in:
> 
>   fs/ext4/super.c
> 
> between commit:
> 
>   ffea255f4052 ("ext4: Fix reusing stale buffer heads from last failed mounting")
> 
> from the ext4 tree and commits:
> 
>   2736e8eeb0cc ("block: use the holder as indication for exclusive opens")
>   a42fb5a75ccc ("ext4: Fix warning in blkdev_put()")
> 
> from the block tree.
> 
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging.  You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
> 
> -- 
> Cheers,
> Stephen Rothwell
> 
> diff --cc fs/ext4/super.c
> index b3819e70093e,64342adcd679..000000000000
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@@ -1128,13 -1133,7 +1133,13 @@@ static void ext4_blkdev_remove(struct e
>   	struct block_device *bdev;
>   	bdev = sbi->s_journal_bdev;
>   	if (bdev) {
>  +		/*
>  +		 * Invalidate the journal device's buffers.  We don't want them
>  +		 * floating about in memory - the physical journal device may
>  +		 * hotswapped, and it breaks the `ro-after' testing code.
>  +		 */
>  +		invalidate_bdev(bdev);
> - 		ext4_blkdev_put(bdev);
> + 		blkdev_put(bdev, sbi->s_sb);
>   		sbi->s_journal_bdev = NULL;
>   	}
>   }

This is now a conflict between the ext4 tree and Linus' tree.

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: manual merge of the block tree with the ext4 tree

[Christoph Hellwig]

Thanks Stephen,

the merge looks good to me.

linux-next: manual merge of the block tree with the ext4 tree

[Stephen Rothwell]

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Hi all,

Today's linux-next merge of the block tree got a conflict in:

  fs/ext4/super.c

between commit:

  ffea255f4052 ("ext4: Fix reusing stale buffer heads from last failed mounting")

from the ext4 tree and commits:

  2736e8eeb0cc ("block: use the holder as indication for exclusive opens")
  a42fb5a75ccc ("ext4: Fix warning in blkdev_put()")

from the block tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc fs/ext4/super.c
index b3819e70093e,64342adcd679..000000000000
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@@ -1128,13 -1133,7 +1133,13 @@@ static void ext4_blkdev_remove(struct e
  	struct block_device *bdev;
  	bdev = sbi->s_journal_bdev;
  	if (bdev) {
 +		/*
 +		 * Invalidate the journal device's buffers.  We don't want them
 +		 * floating about in memory - the physical journal device may
 +		 * hotswapped, and it breaks the `ro-after' testing code.
 +		 */
 +		invalidate_bdev(bdev);
- 		ext4_blkdev_put(bdev);
+ 		blkdev_put(bdev, sbi->s_sb);
  		sbi->s_journal_bdev = NULL;
  	}
  }

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Re: linux-next: manual merge of the block tree with the ext4 tree

[Christoph Hellwig]

Hi Stephen,

the merge looks good to me, thanks.

linux-next: manual merge of the block tree with the ext4 tree

[Stephen Rothwell]

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Hi all,

Today's linux-next merge of the block tree got a conflict in:

  fs/ext4/super.c

between commit:

  63bc068f0d1a ("ext4: Fix reusing stale buffer heads from last failed mounting")

from the ext4 tree and commit:

  2736e8eeb0cc ("block: use the holder as indication for exclusive opens")

from the block tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc fs/ext4/super.c
index b3819e70093e,94a7b56ed876..000000000000
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@@ -1128,13 -1133,7 +1133,13 @@@ static void ext4_blkdev_remove(struct e
  	struct block_device *bdev;
  	bdev = sbi->s_journal_bdev;
  	if (bdev) {
 +		/*
 +		 * Invalidate the journal device's buffers.  We don't want them
 +		 * floating about in memory - the physical journal device may
 +		 * hotswapped, and it breaks the `ro-after' testing code.
 +		 */
 +		invalidate_bdev(bdev);
- 		ext4_blkdev_put(bdev);
+ 		blkdev_put(bdev, sbi->s_es);
  		sbi->s_journal_bdev = NULL;
  	}
  }

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linux-next: manual merge of the block tree with the ext4 tree

[Stephen Rothwell]

Hi all,

Today's linux-next merge of the block tree got a conflict in:

  fs/ext4/crypto.c

between commit:

  a7550b30ab70 ("ext4 crypto: migrate into vfs's crypto engine")

from the ext4 tree and commits:

  4e49ea4a3d27 ("block/fs/drivers: remove rw argument from submit_bio")
  60a40096a3b2 ("ext4: use bio op helprs in ext4 crypto code")

from the block tree.

I fixed it up (the ext4 tree removed the file, so I did that) and can
carry the fix as necessary. This is now fixed as far as linux-next is
concerned, but any non trivial conflicts should be mentioned to your
upstream maintainer when your tree is submitted for merging.  You may
also want to consider cooperating with the maintainer of the conflicting
tree to minimise any particularly complex conflicts.



-- 
Cheers,
Stephen Rothwell

linux-next: manual merge of the block tree with the ext4 tree

[Stephen Rothwell]

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Hi Jens,

Today's linux-next merge of the block tree got a conflict in
fs/fs-writeback.c between commit 74ba19abbeae ("vfs: add support for a
lazytime mount option") from the ext4 tree and commit 9c6ac78eb352
("writeback: fix a subtle race condition in I_DIRTY clearing") from the
block tree.

I fixed it up (maybe, please check - see below) and can carry the fix
as necessary (no action is required).

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

diff --cc fs/fs-writeback.c
index cab2d6d74828,2d609a5fbfea..000000000000
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@@ -480,12 -479,28 +480,28 @@@ __writeback_single_inode(struct inode *
  	 * write_inode()
  	 */
  	spin_lock(&inode->i_lock);
- 	/* Clear I_DIRTY_PAGES if we've written out all dirty pages */
- 	if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
- 		inode->i_state &= ~I_DIRTY_PAGES;
+ 
  	dirty = inode->i_state & I_DIRTY;
- 	inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_TIME);
 -	inode->i_state &= ~I_DIRTY;
++	inode->i_state &= ~(I_DIRTY | I_DIRTY_TIME);
+ 
+ 	/*
+ 	 * Paired with smp_mb() in __mark_inode_dirty().  This allows
+ 	 * __mark_inode_dirty() to test i_state without grabbing i_lock -
+ 	 * either they see the I_DIRTY bits cleared or we see the dirtied
+ 	 * inode.
+ 	 *
+ 	 * I_DIRTY_PAGES is always cleared together above even if @mapping
+ 	 * still has dirty pages.  The flag is reinstated after smp_mb() if
+ 	 * necessary.  This guarantees that either __mark_inode_dirty()
+ 	 * sees clear I_DIRTY_PAGES or we see PAGECACHE_TAG_DIRTY.
+ 	 */
+ 	smp_mb();
+ 
+ 	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
+ 		inode->i_state |= I_DIRTY_PAGES;
+ 
  	spin_unlock(&inode->i_lock);
+ 
  	/* Don't write the inode if only I_DIRTY_PAGES was set */
  	if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
  		int err = write_inode(inode, wbc);

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Re: linux-next: manual merge of the block tree with the ext4 tree

[Stephen Rothwell]

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Hi Ted,

On Tue, 21 Sep 2010 14:04:10 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Today's linux-next merge of the block tree got a conflict in
> fs/ext4/mballoc.c between commit 9c543072a9dd7cf60cbf472914a6480ffda50b27
> ("ext4: Check for negative error code from sb_issue_discard") from the
> ext4 tree and commit 2cf6d26a354ab6362e301b5a323832b02867df47 ("block:
> pass gfp_mask and flags to sb_issue_discard") from the block tree.
> 
> Just context changes.  I fixed it up (see below) and can carry the fix as
> necessary.
> 
> diff --cc fs/ext4/mballoc.c
> index e4f4dae,19aa0d4..0000000
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@@ -2612,8 -2566,8 +2612,8 @@@ static inline void ext4_issue_discard(s
>   	discard_block = block + ext4_group_first_block_no(sb, block_group);
>   	trace_ext4_discard_blocks(sb,
>   			(unsigned long long) discard_block, count);
> - 	ret = sb_issue_discard(sb, discard_block, count);
> + 	ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
>  -	if (ret == EOPNOTSUPP) {
>  +	if (ret == -EOPNOTSUPP) {
>   		ext4_warning(sb, "discard not supported, disabling");
>   		clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
>   	}

This merge fix will now be necessary when merging with Linus' current tree.
-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

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linux-next: manual merge of the block tree with the ext4 tree

[Stephen Rothwell]

Hi Jens,

Today's linux-next merge of the block tree got a conflict in
fs/ext4/mballoc.c between commit 9c543072a9dd7cf60cbf472914a6480ffda50b27
("ext4: Check for negative error code from sb_issue_discard") from the
ext4 tree and commit 2cf6d26a354ab6362e301b5a323832b02867df47 ("block:
pass gfp_mask and flags to sb_issue_discard") from the block tree.

Just context changes.  I fixed it up (see below) and can carry the fix as
necessary.
-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

diff --cc fs/ext4/mballoc.c
index e4f4dae,19aa0d4..0000000
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@@ -2612,8 -2566,8 +2612,8 @@@ static inline void ext4_issue_discard(s
  	discard_block = block + ext4_group_first_block_no(sb, block_group);
  	trace_ext4_discard_blocks(sb,
  			(unsigned long long) discard_block, count);
- 	ret = sb_issue_discard(sb, discard_block, count);
+ 	ret = sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0);
 -	if (ret == EOPNOTSUPP) {
 +	if (ret == -EOPNOTSUPP) {
  		ext4_warning(sb, "discard not supported, disabling");
  		clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
  	}

linux-next: manual merge of the block tree with the ext4 tree

[Stephen Rothwell]

Hi Jens,

Today's linux-next merge of the block tree got a conflict in
fs/ext4/fsync.c between commit a68513a1c88248ee9167a25e32ee8164c3dde02b
("ext4: check missed return value in ext4_sync_file()") from the ext4
tree and commit fbd9b09a177a481eda256447c881f014f29034fe ("blkdev:
generalize flags for blkdev_issue_fn functions") from the block tree.

Just context changes.  I fixed it up (see below) and can carry the fix as
necessary.
-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

diff --cc fs/ext4/fsync.c
index 42bd94a,ef3d980e6..0000000
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@@ -100,9 -100,11 +100,11 @@@ int ext4_sync_file(struct file *file, s
  		if (ext4_should_writeback_data(inode) &&
  		    (journal->j_fs_dev != journal->j_dev) &&
  		    (journal->j_flags & JBD2_BARRIER))
- 			blkdev_issue_flush(inode->i_sb->s_bdev, NULL);
+ 			blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL,
+ 					NULL, BLKDEV_IFL_WAIT);
 -		jbd2_log_wait_commit(journal, commit_tid);
 +		ret = jbd2_log_wait_commit(journal, commit_tid);
  	} else if (journal->j_flags & JBD2_BARRIER)
- 		blkdev_issue_flush(inode->i_sb->s_bdev, NULL);
+ 		blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
+ 			BLKDEV_IFL_WAIT);
  	return ret;
  }