linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Andreas Gruenbacher <agruenba@redhat.com>
To: cluster-devel@redhat.com, Christoph Hellwig <hch@lst.de>
Cc: linux-fsdevel@vger.kernel.org, Andreas Gruenbacher <agruenba@redhat.com>
Subject: [PATCH v6 4/9] iomap: Generic inline data handling
Date: Sat,  2 Jun 2018 11:57:12 +0200	[thread overview]
Message-ID: <20180602095717.31641-5-agruenba@redhat.com> (raw)
In-Reply-To: <20180602095717.31641-1-agruenba@redhat.com>

Add generic inline data handling by adding a pointer to the inline data
region to struct iomap.  When handling a buffered IOMAP_INLINE write,
iomap_write_begin will copy the current inline data from the inline data
region into the page cache, and iomap_write_end will copy the changes in
the page cache back to the inline data region.

This doesn't cover inline data reads and direct I/O yet because so far,
we have no users.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/buffer.c                 | 20 ++++++++-----
 fs/iomap.c                  | 56 ++++++++++++++++++++++++++++++++++---
 include/linux/buffer_head.h |  3 ++
 include/linux/iomap.h       |  1 +
 4 files changed, 69 insertions(+), 11 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index 5220d9efcd18..cfd1ad2a5805 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2112,15 +2112,12 @@ int block_write_end(struct file *file, struct address_space *mapping,
 }
 EXPORT_SYMBOL(block_write_end);
 
-int generic_write_end(struct file *file, struct address_space *mapping,
+void __generic_write_end(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned copied,
-			struct page *page, void *fsdata)
+			struct page *page, void *fsdata, bool dirty_inode)
 {
 	struct inode *inode = mapping->host;
 	loff_t old_size = inode->i_size;
-	int i_size_changed = 0;
-
-	copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
 
 	/*
 	 * No need to use i_size_read() here, the i_size
@@ -2131,7 +2128,7 @@ int generic_write_end(struct file *file, struct address_space *mapping,
 	 */
 	if (pos+copied > inode->i_size) {
 		i_size_write(inode, pos+copied);
-		i_size_changed = 1;
+		dirty_inode = true;
 	}
 
 	unlock_page(page);
@@ -2145,9 +2142,18 @@ int generic_write_end(struct file *file, struct address_space *mapping,
 	 * ordering of page lock and transaction start for journaling
 	 * filesystems.
 	 */
-	if (i_size_changed)
+	if (dirty_inode)
 		mark_inode_dirty(inode);
+}
 
+int generic_write_end(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
+{
+	copied = block_write_end(file, mapping, pos, len, copied,
+				 page, fsdata);
+	__generic_write_end(file, mapping, pos, len, copied,
+			    page, fsdata, false);
 	return copied;
 }
 EXPORT_SYMBOL(generic_write_end);
diff --git a/fs/iomap.c b/fs/iomap.c
index a0d3b7742060..857c4b7b54eb 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -108,6 +108,40 @@ iomap_write_failed(struct inode *inode, loff_t pos, unsigned len)
 		truncate_pagecache_range(inode, max(pos, i_size), pos + len);
 }
 
+static void
+iomap_read_inline_data(struct page *page, struct iomap *iomap, loff_t size)
+{
+	void *data = iomap->inline_data;
+	void *addr;
+
+	if (PageUptodate(page))
+		return;
+
+	BUG_ON(page->index);
+	BUG_ON(size > PAGE_SIZE - offset_in_page(data));
+
+	addr = kmap_atomic(page);
+	memcpy(addr, data, size);
+	memset(addr + size, 0, PAGE_SIZE - size);
+	kunmap_atomic(addr);
+	SetPageUptodate(page);
+}
+
+static void
+iomap_write_inline_data(struct page *page, struct iomap *iomap, off_t pos,
+		unsigned copied)
+{
+	void *data = iomap->inline_data;
+	void *addr;
+
+	BUG_ON(pos + copied > PAGE_SIZE - offset_in_page(data));
+	WARN_ON_ONCE(!PageUptodate(page));
+
+	addr = kmap_atomic(page);
+	memcpy(data + pos, addr + pos, copied);
+	kunmap_atomic(addr);
+}
+
 static int
 iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
 		struct page **pagep, struct iomap *iomap)
@@ -125,6 +159,11 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
 	if (!page)
 		return -ENOMEM;
 
+	if (iomap->type == IOMAP_INLINE) {
+		iomap_read_inline_data(page, iomap, inode->i_size);
+		goto out;
+	}
+
 	status = __block_write_begin_int(page, pos, len, NULL, iomap);
 	if (unlikely(status)) {
 		unlock_page(page);
@@ -134,16 +173,24 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags,
 		iomap_write_failed(inode, pos, len);
 	}
 
+out:
 	*pagep = page;
 	return status;
 }
 
 static int
 iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
-		unsigned copied, struct page *page)
+		unsigned copied, struct page *page, struct iomap *iomap)
 {
 	int ret;
 
+	if (iomap->type == IOMAP_INLINE) {
+		iomap_write_inline_data(page, iomap, pos, copied);
+		__generic_write_end(NULL, inode->i_mapping, pos, len,
+				copied, page, NULL, true);
+		return copied;
+	}
+
 	ret = generic_write_end(NULL, inode->i_mapping, pos, len,
 			copied, page, NULL);
 	if (ret < len)
@@ -200,7 +247,8 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 
 		flush_dcache_page(page);
 
-		status = iomap_write_end(inode, pos, bytes, copied, page);
+		status = iomap_write_end(inode, pos, bytes, copied, page,
+				iomap);
 		if (unlikely(status < 0))
 			break;
 		copied = status;
@@ -294,7 +342,7 @@ iomap_dirty_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 
 		WARN_ON_ONCE(!PageUptodate(page));
 
-		status = iomap_write_end(inode, pos, bytes, bytes, page);
+		status = iomap_write_end(inode, pos, bytes, bytes, page, iomap);
 		if (unlikely(status <= 0)) {
 			if (WARN_ON_ONCE(status == 0))
 				return -EIO;
@@ -346,7 +394,7 @@ static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
 	zero_user(page, offset, bytes);
 	mark_page_accessed(page);
 
-	return iomap_write_end(inode, pos, bytes, bytes, page);
+	return iomap_write_end(inode, pos, bytes, bytes, page, iomap);
 }
 
 static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes,
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 894e5d125de6..c730ae8888a8 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -231,6 +231,9 @@ int __block_write_begin(struct page *page, loff_t pos, unsigned len,
 int block_write_end(struct file *, struct address_space *,
 				loff_t, unsigned, unsigned,
 				struct page *, void *);
+void __generic_write_end(struct file *, struct address_space *,
+			 loff_t, unsigned, unsigned,
+			 struct page *, void *, bool);
 int generic_write_end(struct file *, struct address_space *,
 				loff_t, unsigned, unsigned,
 				struct page *, void *);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 918f14075702..c61113c71a60 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -47,6 +47,7 @@ struct iomap {
 	u64			length;	/* length of mapping, bytes */
 	u16			type;	/* type of mapping */
 	u16			flags;	/* flags for mapping */
+	void			*inline_data;  /* inline data buffer */
 	struct block_device	*bdev;	/* block device for I/O */
 	struct dax_device	*dax_dev; /* dax_dev for dax operations */
 };
-- 
2.17.0

  parent reply	other threads:[~2018-06-02  9:57 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-02  9:57 [PATCH v6 0/9] gfs2 iomap write support Andreas Gruenbacher
2018-06-02  9:57 ` [PATCH v6 1/9] iomap: inline data should be an iomap type, not a flag Andreas Gruenbacher
2018-06-02  9:57 ` [PATCH v6 2/9] iomap: Mark newly allocated buffer heads as new Andreas Gruenbacher
2018-06-02 16:58   ` Christoph Hellwig
2018-06-02  9:57 ` [PATCH v6 3/9] iomap: Complete partial direct I/O writes synchronously Andreas Gruenbacher
2018-06-02 16:58   ` Christoph Hellwig
2018-06-02  9:57 ` Andreas Gruenbacher [this message]
2018-06-02 17:04   ` [PATCH v6 4/9] iomap: Generic inline data handling Christoph Hellwig
2018-06-04 12:02     ` Andreas Grünbacher
2018-06-04 12:12       ` Christoph Hellwig
2018-06-04 17:01         ` Andreas Grünbacher
2018-06-02  9:57 ` [PATCH v6 5/9] iomap: Add write_end iomap operation Andreas Gruenbacher
2018-06-02 17:06   ` Christoph Hellwig
2018-06-04 12:03     ` Andreas Grünbacher
2018-06-02  9:57 ` [PATCH v6 6/9] gfs2: iomap buffered write support Andreas Gruenbacher
2018-06-02  9:57 ` [PATCH v6 7/9] gfs2: gfs2_extent_length cleanup Andreas Gruenbacher
2018-06-02  9:57 ` [PATCH v6 8/9] gfs2: iomap direct I/O support Andreas Gruenbacher
2018-06-02  9:57 ` [PATCH v6 9/9] gfs2: Remove gfs2_write_{begin,end} Andreas Gruenbacher

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180602095717.31641-5-agruenba@redhat.com \
    --to=agruenba@redhat.com \
    --cc=cluster-devel@redhat.com \
    --cc=hch@lst.de \
    --cc=linux-fsdevel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).