diff mbox

[04/11] ext4: Add ext4_get_block_dax()

Message ID 1438718285-21168-5-git-send-email-matthew.r.wilcox@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wilcox, Matthew R Aug. 4, 2015, 7:57 p.m. UTC
From: Matthew Wilcox <willy@linux.intel.com>

DAX wants different semantics from any currently-existing ext4
get_block callback.  Unlike ext4_get_block_write(), it needs to honour
the 'create' flag, and unlike ext4_get_block(), it needs to be able
to return unwritten extents.  So introduce a new ext4_get_block_dax()
which has those semantics.  We could also change ext4_get_block_write()
to honour the 'create' flag, but that might have consequences on other
users that I do not currently understand.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
 fs/ext4/ext4.h  |  2 ++
 fs/ext4/file.c  |  6 +++---
 fs/ext4/inode.c | 11 +++++++++++
 3 files changed, 16 insertions(+), 3 deletions(-)

Comments

Dave Chinner Aug. 5, 2015, 2:03 a.m. UTC | #1
On Tue, Aug 04, 2015 at 03:57:58PM -0400, Matthew Wilcox wrote:
> From: Matthew Wilcox <willy@linux.intel.com>
> 
> DAX wants different semantics from any currently-existing ext4
> get_block callback.  Unlike ext4_get_block_write(), it needs to honour
> the 'create' flag, and unlike ext4_get_block(), it needs to be able
> to return unwritten extents.  So introduce a new ext4_get_block_dax()
> which has those semantics.  We could also change ext4_get_block_write()
> to honour the 'create' flag, but that might have consequences on other
> users that I do not currently understand.
> 
> Signed-off-by: Matthew Wilcox <willy@linux.intel.com>

Doesn't this make the first patch in the series redundant?

Cheers,

Dave.
Matthew Wilcox Aug. 5, 2015, 3:19 p.m. UTC | #2
On Wed, Aug 05, 2015 at 12:03:57PM +1000, Dave Chinner wrote:
> On Tue, Aug 04, 2015 at 03:57:58PM -0400, Matthew Wilcox wrote:
> > From: Matthew Wilcox <willy@linux.intel.com>
> > 
> > DAX wants different semantics from any currently-existing ext4
> > get_block callback.  Unlike ext4_get_block_write(), it needs to honour
> > the 'create' flag, and unlike ext4_get_block(), it needs to be able
> > to return unwritten extents.  So introduce a new ext4_get_block_dax()
> > which has those semantics.  We could also change ext4_get_block_write()
> > to honour the 'create' flag, but that might have consequences on other
> > users that I do not currently understand.
> > 
> > Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
> 
> Doesn't this make the first patch in the series redundant?

As I explained in the cover letter, patch 1 already went to Ted.  It might
be on its way in, and it might not.  Rather than sending a patch that
applies to current mainline and forcing someone to fix up a conflict
later, better to resend the patch as part of this series, and our tools
will do the right thing no matter which order patches go into Linus' tree.
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diff mbox

Patch

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index d743d93..51c5008 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2274,6 +2274,8 @@  struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
 int ext4_get_block_write(struct inode *inode, sector_t iblock,
 			 struct buffer_head *bh_result, int create);
+int ext4_get_block_dax(struct inode *inode, sector_t iblock,
+			 struct buffer_head *bh_result, int create);
 int ext4_get_block(struct inode *inode, sector_t iblock,
 				struct buffer_head *bh_result, int create);
 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index ca5302a..d5219e4 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -207,19 +207,19 @@  static void ext4_end_io_unwritten(struct buffer_head *bh, int uptodate)
 
 static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-	return dax_fault(vma, vmf, ext4_get_block_write, ext4_end_io_unwritten);
+	return dax_fault(vma, vmf, ext4_get_block_dax, ext4_end_io_unwritten);
 }
 
 static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
 						pmd_t *pmd, unsigned int flags)
 {
-	return dax_pmd_fault(vma, addr, pmd, flags, ext4_get_block_write,
+	return dax_pmd_fault(vma, addr, pmd, flags, ext4_get_block_dax,
 				ext4_end_io_unwritten);
 }
 
 static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-	return dax_mkwrite(vma, vmf, ext4_get_block_write,
+	return dax_mkwrite(vma, vmf, ext4_get_block_dax,
 				ext4_end_io_unwritten);
 }
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 40e6c66..75146d1 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3025,6 +3025,17 @@  static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
 			       EXT4_GET_BLOCKS_NO_LOCK);
 }
 
+int ext4_get_block_dax(struct inode *inode, sector_t iblock,
+		   struct buffer_head *bh_result, int create)
+{
+	int flags = EXT4_GET_BLOCKS_PRE_IO | EXT4_GET_BLOCKS_UNWRIT_EXT;
+	if (create)
+		flags |= EXT4_GET_BLOCKS_CREATE;
+	ext4_debug("ext4_get_block_dax: inode %lu, create flag %d\n",
+		   inode->i_ino, create);
+	return _ext4_get_block(inode, iblock, bh_result, flags);
+}
+
 static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
 			    ssize_t size, void *private)
 {