[PATCHSET v5.0 5/9] xfs: preparation for realtime allocation groups

[PATCHSET v5.0 5/9] xfs: preparation for realtime allocation groups

[Darrick J. Wong]

Hi all,

Prepare for realtime groups by adding a few bug fixes and generic code
that will be necessary.

If you're going to start using this code, I strongly recommend pulling
from my git trees, which are linked below.

This has been running on the djcloud for months with no problems.  Enjoy!
Comments and questions are, as always, welcome.

--D

kernel git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=rtgroups-prep

xfsprogs git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=rtgroups-prep
---
Commits in this patchset:
 * xfs: fix rt device offset calculations for FITRIM
 * iomap: add a merge boundary flag
---
 fs/iomap/buffered-io.c |    6 ++++++
 fs/xfs/xfs_discard.c   |   19 +++++++++++--------
 include/linux/iomap.h  |    4 ++++
 3 files changed, 21 insertions(+), 8 deletions(-)

[PATCH 1/2] xfs: fix rt device offset calculations for FITRIM

[Darrick J. Wong]

From: Darrick J. Wong <djwong@kernel.org>

FITRIM on xfs has this bizarro uapi where we flatten all the physically
addressable storage across two block devices into a linear address
space.  In this address space, the realtime device comes immediately
after the data device.  Therefore, the xfs_trim_rtdev_extents has to
convert its input parameters from the linear address space to actual
rtdev block addresses on the realtime volume.

Right now the address space conversion is done in units of rtblocks.
However, a future patchset will convert xfs_rtblock_t to be a segmented
address space (group:blkno) like the data device.  Change the conversion
code to be done in units of daddrs since those will never be segmented.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/xfs/xfs_discard.c |   19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)


diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c
index 34fe6bbeb2a76f..83cc68508a7f6c 100644
--- a/fs/xfs/xfs_discard.c
+++ b/fs/xfs/xfs_discard.c
@@ -480,7 +480,7 @@ xfs_discard_rtdev_extents(
 		trace_xfs_discard_rtextent(mp, busyp->bno, busyp->length);
 
 		error = __blkdev_issue_discard(bdev,
-				XFS_FSB_TO_BB(mp, busyp->bno),
+				xfs_rtb_to_daddr(mp, busyp->bno),
 				XFS_FSB_TO_BB(mp, busyp->length),
 				GFP_NOFS, &bio);
 		if (error)
@@ -612,22 +612,25 @@ xfs_trim_rtdev_extents(
 	xfs_rtblock_t		start_rtbno, end_rtbno;
 	xfs_rtxnum_t		start_rtx, end_rtx;
 	xfs_rgnumber_t		start_rgno, end_rgno;
+	xfs_daddr_t		daddr_offset;
 	int			last_error = 0, error;
 	struct xfs_rtgroup	*rtg = NULL;
 
 	/* Shift the start and end downwards to match the rt device. */
+	daddr_offset = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
+	if (start > daddr_offset)
+		start -= daddr_offset;
+	else
+		start = 0;
 	start_rtbno = xfs_daddr_to_rtb(mp, start);
-	if (start_rtbno > mp->m_sb.sb_dblocks)
-		start_rtbno -= mp->m_sb.sb_dblocks;
-	else
-		start_rtbno = 0;
 	start_rtx = xfs_rtb_to_rtx(mp, start_rtbno);
 	start_rgno = xfs_rtb_to_rgno(mp, start_rtbno);
 
+	if (end <= daddr_offset)
+		return 0;
+	else
+		end -= daddr_offset;
 	end_rtbno = xfs_daddr_to_rtb(mp, end);
-	if (end_rtbno <= mp->m_sb.sb_dblocks)
-		return 0;
-	end_rtbno -= mp->m_sb.sb_dblocks;
 	end_rtx = xfs_rtb_to_rtx(mp, end_rtbno + mp->m_sb.sb_rextsize - 1);
 	end_rgno = xfs_rtb_to_rgno(mp, end_rtbno);
 

[PATCH 2/2] iomap: add a merge boundary flag

[Darrick J. Wong]

From: Christoph Hellwig <hch@lst.de>

File systems might have boundaries over which merges aren't possible.
In fact these are very common, although most of the time some kind of
header at the beginning of this region (e.g. XFS alloation groups, ext4
block groups) automatically create a merge barrier.  But if that is
not present, say for a device purely used for data we need to manually
communicate that to iomap.

Add a IOMAP_F_BOUNDARY flag to never merge I/O into a previous mapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/iomap/buffered-io.c |    6 ++++++
 include/linux/iomap.h  |    4 ++++
 2 files changed, 10 insertions(+)


diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 3899169b2cf733..6f7691ef1e4164 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -1657,6 +1657,8 @@ iomap_ioend_can_merge(struct iomap_ioend *ioend, struct iomap_ioend *next)
 {
 	if (ioend->io_bio.bi_status != next->io_bio.bi_status)
 		return false;
+	if (next->io_flags & IOMAP_F_BOUNDARY)
+		return false;
 	if ((ioend->io_flags & IOMAP_F_SHARED) ^
 	    (next->io_flags & IOMAP_F_SHARED))
 		return false;
@@ -1776,6 +1778,8 @@ static struct iomap_ioend *iomap_alloc_ioend(struct iomap_writepage_ctx *wpc,
 	INIT_LIST_HEAD(&ioend->io_list);
 	ioend->io_type = wpc->iomap.type;
 	ioend->io_flags = wpc->iomap.flags;
+	if (pos > wpc->iomap.offset)
+		wpc->iomap.flags &= ~IOMAP_F_BOUNDARY;
 	ioend->io_inode = inode;
 	ioend->io_size = 0;
 	ioend->io_offset = pos;
@@ -1787,6 +1791,8 @@ static struct iomap_ioend *iomap_alloc_ioend(struct iomap_writepage_ctx *wpc,
 
 static bool iomap_can_add_to_ioend(struct iomap_writepage_ctx *wpc, loff_t pos)
 {
+	if (wpc->iomap.offset == pos && (wpc->iomap.flags & IOMAP_F_BOUNDARY))
+		return false;
 	if ((wpc->iomap.flags & IOMAP_F_SHARED) !=
 	    (wpc->ioend->io_flags & IOMAP_F_SHARED))
 		return false;
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index d8a7fc84348c4d..d44c982085a39f 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -53,6 +53,9 @@ struct vm_fault;
  *
  * IOMAP_F_XATTR indicates that the iomap is for an extended attribute extent
  * rather than a file data extent.
+ *
+ * IOMAP_F_BOUNDARY indicates that I/O and I/O completions for this iomap must
+ * never be merged with the mapping before it.
  */
 #define IOMAP_F_NEW		(1U << 0)
 #define IOMAP_F_DIRTY		(1U << 1)
@@ -64,6 +67,7 @@ struct vm_fault;
 #define IOMAP_F_BUFFER_HEAD	0
 #endif /* CONFIG_BUFFER_HEAD */
 #define IOMAP_F_XATTR		(1U << 5)
+#define IOMAP_F_BOUNDARY	(1U << 6)
 
 /*
  * Flags set by the core iomap code during operations:

Re: [PATCH 1/2] xfs: fix rt device offset calculations for FITRIM

[Christoph Hellwig]

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

[PATCH 1/2] xfs: fix rt device offset calculations for FITRIM

[Darrick J. Wong]

From: Darrick J. Wong <djwong@kernel.org>

FITRIM on xfs has this bizarro uapi where we flatten all the physically
addressable storage across two block devices into a linear address
space.  In this address space, the realtime device comes immediately
after the data device.  Therefore, the xfs_trim_rtdev_extents has to
convert its input parameters from the linear address space to actual
rtdev block addresses on the realtime volume.

Right now the address space conversion is done in units of rtblocks.
However, a future patchset will convert xfs_rtblock_t to be a segmented
address space (group:blkno) like the data device.  Change the conversion
code to be done in units of daddrs since those will never be segmented.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_discard.c |   19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)


diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c
index 4f3e4736f13ea6..42b8b5e0e931b7 100644
--- a/fs/xfs/xfs_discard.c
+++ b/fs/xfs/xfs_discard.c
@@ -480,7 +480,7 @@ xfs_discard_rtdev_extents(
 		trace_xfs_discard_rtextent(mp, busyp->bno, busyp->length);
 
 		error = __blkdev_issue_discard(bdev,
-				XFS_FSB_TO_BB(mp, busyp->bno),
+				xfs_rtb_to_daddr(mp, busyp->bno),
 				XFS_FSB_TO_BB(mp, busyp->length),
 				GFP_NOFS, &bio);
 		if (error)
@@ -612,22 +612,25 @@ xfs_trim_rtdev_extents(
 	xfs_rtblock_t		start_rtbno, end_rtbno;
 	xfs_rtxnum_t		start_rtx, end_rtx;
 	xfs_rgnumber_t		start_rgno, end_rgno;
+	xfs_daddr_t		daddr_offset;
 	int			last_error = 0, error;
 	struct xfs_rtgroup	*rtg = NULL;
 
 	/* Shift the start and end downwards to match the rt device. */
+	daddr_offset = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
+	if (start > daddr_offset)
+		start -= daddr_offset;
+	else
+		start = 0;
 	start_rtbno = xfs_daddr_to_rtb(mp, start);
-	if (start_rtbno > mp->m_sb.sb_dblocks)
-		start_rtbno -= mp->m_sb.sb_dblocks;
-	else
-		start_rtbno = 0;
 	start_rtx = xfs_rtb_to_rtx(mp, start_rtbno);
 	start_rgno = xfs_rtb_to_rgno(mp, start_rtbno);
 
+	if (end <= daddr_offset)
+		return 0;
+	else
+		end -= daddr_offset;
 	end_rtbno = xfs_daddr_to_rtb(mp, end);
-	if (end_rtbno <= mp->m_sb.sb_dblocks)
-		return 0;
-	end_rtbno -= mp->m_sb.sb_dblocks;
 	end_rtx = xfs_rtb_to_rtx(mp, end_rtbno + mp->m_sb.sb_rextsize - 1);
 	end_rgno = xfs_rtb_to_rgno(mp, end_rtbno);
 

[PATCH 1/2] xfs: fix rt device offset calculations for FITRIM

[Darrick J. Wong]

From: Darrick J. Wong <djwong@kernel.org>

FITRIM on xfs has this bizarro uapi where we flatten all the physically
addressable storage across two block devices into a linear address
space.  In this address space, the realtime device comes immediately
after the data device.  Therefore, the xfs_trim_rtdev_extents has to
convert its input parameters from the linear address space to actual
rtdev block addresses on the realtime volume.

Right now the address space conversion is done in units of rtblocks.
However, a future patchset will convert xfs_rtblock_t to be a segmented
address space (group:blkno) like the data device.  Change the conversion
code to be done in units of daddrs since those will never be segmented.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_discard.c |   19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)


diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c
index 4f3e4736f13ea6..42b8b5e0e931b7 100644
--- a/fs/xfs/xfs_discard.c
+++ b/fs/xfs/xfs_discard.c
@@ -480,7 +480,7 @@ xfs_discard_rtdev_extents(
 		trace_xfs_discard_rtextent(mp, busyp->bno, busyp->length);
 
 		error = __blkdev_issue_discard(bdev,
-				XFS_FSB_TO_BB(mp, busyp->bno),
+				xfs_rtb_to_daddr(mp, busyp->bno),
 				XFS_FSB_TO_BB(mp, busyp->length),
 				GFP_NOFS, &bio);
 		if (error)
@@ -612,22 +612,25 @@ xfs_trim_rtdev_extents(
 	xfs_rtblock_t		start_rtbno, end_rtbno;
 	xfs_rtxnum_t		start_rtx, end_rtx;
 	xfs_rgnumber_t		start_rgno, end_rgno;
+	xfs_daddr_t		daddr_offset;
 	int			last_error = 0, error;
 	struct xfs_rtgroup	*rtg = NULL;
 
 	/* Shift the start and end downwards to match the rt device. */
+	daddr_offset = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
+	if (start > daddr_offset)
+		start -= daddr_offset;
+	else
+		start = 0;
 	start_rtbno = xfs_daddr_to_rtb(mp, start);
-	if (start_rtbno > mp->m_sb.sb_dblocks)
-		start_rtbno -= mp->m_sb.sb_dblocks;
-	else
-		start_rtbno = 0;
 	start_rtx = xfs_rtb_to_rtx(mp, start_rtbno);
 	start_rgno = xfs_rtb_to_rgno(mp, start_rtbno);
 
+	if (end <= daddr_offset)
+		return 0;
+	else
+		end -= daddr_offset;
 	end_rtbno = xfs_daddr_to_rtb(mp, end);
-	if (end_rtbno <= mp->m_sb.sb_dblocks)
-		return 0;
-	end_rtbno -= mp->m_sb.sb_dblocks;
 	end_rtx = xfs_rtb_to_rtx(mp, end_rtbno + mp->m_sb.sb_rextsize - 1);
 	end_rgno = xfs_rtb_to_rgno(mp, end_rtbno);