[Cluster-devel] [PATCH 0/3] gfs2: More iomap enablement

[Cluster-devel] [PATCH 0/3] gfs2: More iomap enablement

[Andreas Gruenbacher]

Hi,

here's another forward-looking fix and two enablement patches.  The
patches depend on the following branches:

  xfs-linux/iomap-4.19-merge
  linux-gfs/for-next

The "iomap: add initial support for writes without buffer heads" patch
on 'iomap-4.19-merge' introduces the IOMAP_F_BUFFER_HEAD flag which
needds to be set for gfs2.  I've done that in the merge commit for that
branch so that we don't end up with any broken commits.

An 'iomap-misc' branch with all those changes can be found here:

  https://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2.git/log/?h=iomap-misc

The 'iomap-4.19-merge' branch can be found in the xfs repository:

  https://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git/log/?h=iomap-4.19-merge

Thanks,
Andreas

Andreas Gruenbacher (3):
  gfs2: fallocate_chunk: Always initialize struct iomap
  gfs2: Use iomap for stuffed direct I/O reads
  gfs2: use iomap_readpage for blocksize == PAGE_SIZE

-- 
2.17.1

[Cluster-devel] [PATCH 1/3] gfs2: fallocate_chunk: Always initialize struct iomap

[Andreas Gruenbacher]

In fallocate_chunk, always initialize the iomap before calling
gfs2_iomap_get_alloc: future changes could otherwise cause things like
iomap.flags to leak across calls.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/gfs2/file.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index f3c6d78659b1..6d895d39158a 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -877,7 +877,6 @@ static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
 	struct gfs2_inode *ip = GFS2_I(inode);
 	loff_t end = offset + len;
 	struct buffer_head *dibh;
-	struct iomap iomap = { };
 	int error;
 
 	error = gfs2_meta_inode_buffer(ip, &dibh);
@@ -893,6 +892,8 @@ static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
 	}
 
 	while (offset < end) {
+		struct iomap iomap = { };
+
 		error = gfs2_iomap_get_alloc(inode, offset, end - offset,
 					     &iomap);
 		if (error)
-- 
2.17.1

[Cluster-devel] [PATCH 2/3] gfs2: Use iomap for stuffed direct I/O reads

[Andreas Gruenbacher]

Remove the fallback code from direct to buffered I/O for stuffed reads.

For stuffed writes, we must keep the fallback code: the deferred glock
we are holding under direct I/O doesn't allow to write to the inode or
change the file size.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/gfs2/file.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 6d895d39158a..08369c6cd127 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -706,14 +706,8 @@ static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to)
 	if (ret)
 		goto out_uninit;
 
-	/* fall back to buffered I/O for stuffed files */
-	ret = -ENOTBLK;
-	if (gfs2_is_stuffed(ip))
-		goto out;
-
 	ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL);
 
-out:
 	gfs2_glock_dq(&gh);
 out_uninit:
 	gfs2_holder_uninit(&gh);
-- 
2.17.1

[Cluster-devel] [PATCH 3/3] gfs2: use iomap_readpage for blocksize == PAGE_SIZE

[Andreas Gruenbacher]

We only use iomap_readpage for pages that don't have buffer heads
attached yet: iomap_readpage would otherwise read pages from disk that
are marked buffer_uptodate() but not PageUptodate().  Those pages may
actually contain data more recent than what's on disk.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/gfs2/aops.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index cc80fd71f3dd..31e8270d0b26 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -508,9 +508,13 @@ static int __gfs2_readpage(void *file, struct page *page)
 {
 	struct gfs2_inode *ip = GFS2_I(page->mapping->host);
 	struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
+
 	int error;
 
-	if (gfs2_is_stuffed(ip)) {
+	if (i_blocksize(page->mapping->host) == PAGE_SIZE &&
+	    !page_has_buffers(page)) {
+		error = iomap_readpage(page, &gfs2_iomap_ops);
+	} else if (gfs2_is_stuffed(ip)) {
 		error = stuffed_readpage(ip, page);
 		unlock_page(page);
 	} else {
-- 
2.17.1

[Cluster-devel] [PATCH 0/3] gfs2: More iomap enablement

[Bob Peterson]

Hi Andreas,

----- Original Message -----
> Andreas Gruenbacher (3):
>   gfs2: fallocate_chunk: Always initialize struct iomap
>   gfs2: Use iomap for stuffed direct I/O reads
>   gfs2: use iomap_readpage for blocksize == PAGE_SIZE

These three look good to me. Feel free to add my Reviewed-by.

Bob Peterson