On Thu, Jan 28, 2021 at 01:10:21PM -0500, Brian Foster wrote:

On Wed, Jan 27, 2021 at 10:01:38PM -0800, Darrick J. Wong wrote:

quoted

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

Modify xfs_trans_reserve_quota_nblks so that we can reserve data and
realtime blocks from the dquot at the same time.  This change has the
theoretical side effect that for allocations to realtime files we will
reserve from the dquot both the number of rtblocks being allocated and
the number of bmbt blocks that might be needed to add the mapping.
However, since the mount code disables quota if it finds a realtime
device, this should not result in any behavior changes.

This also replaces the flags argument with a force? boolean since we

s/?//

quoted

don't need to distinguish between data and rt quota reservations any
more, and the only other flag being passed in was FORCE_RES.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/xfs/libxfs/xfs_attr.c |    6 +-----
 fs/xfs/libxfs/xfs_bmap.c |    4 +---
 fs/xfs/xfs_bmap_util.c   |   20 +++++++++-----------
 fs/xfs/xfs_iomap.c       |   26 +++++++++++++-------------
 fs/xfs/xfs_quota.h       |   10 +++++-----
 fs/xfs/xfs_reflink.c     |    6 ++----
 fs/xfs/xfs_trans_dquot.c |   42 ++++++++++++++++++++++++++++--------------
 7 files changed, 59 insertions(+), 55 deletions(-)

...

quoted

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index f0a8f3377281..d54d9f02d3dd 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c

...

quoted

@@ -792,18 +792,17 @@ xfs_alloc_file_space(
 		if (unlikely(rt)) {
 			resrtextents = qblocks = resblks;

This looks like the last usage of qblocks in the function.

Oops, yes, that can go away.  Fixed.

quoted

 			resrtextents /= mp->m_sb.sb_rextsize;
-			resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
-			quota_flag = XFS_QMOPT_RES_RTBLKS;
+			dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
+			rblocks = resblks;
 		} else {
-			resrtextents = 0;
-			resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
-			quota_flag = XFS_QMOPT_RES_REGBLKS;
+			dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
+			rblocks = 0;
 		}
 
 		/*
 		 * Allocate and setup the transaction.
 		 */
-		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks,
+		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, dblocks,
 				resrtextents, 0, &tp);
 
 		/*

...

quoted

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index de0e371ba4dd..ef29d44c656a 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c

...

quoted

@@ -235,18 +235,19 @@ xfs_iomap_write_direct(
 	if (IS_DAX(VFS_I(ip))) {
 		bmapi_flags = XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO;
 		if (imap->br_state == XFS_EXT_UNWRITTEN) {
+			force = true;
 			tflags |= XFS_TRANS_RESERVE;
-			resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
+			dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;

I'm a little confused what this hunk of logic is for in the first place,

I think this was to prevent racing write faults to an unwritten extent
in an S_DAX file from clobbering each other.  Looking at the dax write
fault path (__xfs_filemap_fault), we only take MMAPLOCK_SHARED, so the
only way we can serialize the storage zeroing that must be done with
unwritten extent conversion is when we take the ILOCK to do the
conversion, aka BMAPI_ZERO.

xfs_direct_write_iomap_begin accomplishes this by (ab|re)using the
"allocation" path to do the extent conversion.  The space is already
allocated, so we only have to reserve enough free space/quota to handle
the bmbt split.

but doesn't this also adjust down the quota where it previously only
affected the transaction reservation? Is that intentional?

So yes, it does adjust down the quota reservation for this one case, but
I don't think we needed it in the first place.  Still, I'll cut out this
part and make it a separate fix patch so that the conversion is more
straightforward.  Thanks for pointing that out.

--D

Brian

quoted

 		}
 	}
-	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, resrtextents,
+	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, dblocks, resrtextents,
 			tflags, &tp);
 	if (error)
 		return error;
 
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 
-	error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
+	error = xfs_trans_reserve_quota_nblks(tp, ip, dblocks, rblocks, force);
 	if (error)
 		goto out_trans_cancel;
 

@@ -559,8 +560,7 @@ xfs_iomap_write_unwritten(
 		xfs_ilock(ip, XFS_ILOCK_EXCL);
 		xfs_trans_ijoin(tp, ip, 0);
 
-		error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0,
-				XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_FORCE_RES);
+		error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0, true);
 		if (error)
 			goto error_on_bmapi_transaction;
 

diff --git a/fs/xfs/xfs_quota.h b/fs/xfs/xfs_quota.h
index 72f4cfc49048..efd04f84d9b4 100644
--- a/fs/xfs/xfs_quota.h
+++ b/fs/xfs/xfs_quota.h

@@ -81,8 +81,8 @@ extern void xfs_trans_mod_dquot_byino(struct xfs_trans *, struct xfs_inode *,
 		uint, int64_t);
 extern void xfs_trans_apply_dquot_deltas(struct xfs_trans *);
 extern void xfs_trans_unreserve_and_mod_dquots(struct xfs_trans *);
-extern int xfs_trans_reserve_quota_nblks(struct xfs_trans *,
-		struct xfs_inode *, int64_t, long, uint);
+int xfs_trans_reserve_quota_nblks(struct xfs_trans *tp, struct xfs_inode *ip,
+		int64_t dblocks, int64_t rblocks, bool force);
 extern int xfs_trans_reserve_quota_bydquots(struct xfs_trans *,
 		struct xfs_mount *, struct xfs_dquot *,
 		struct xfs_dquot *, struct xfs_dquot *, int64_t, long, uint);

@@ -114,8 +114,7 @@ extern void xfs_qm_unmount_quotas(struct xfs_mount *);
 static inline int
 xfs_quota_reserve_blkres(struct xfs_inode *ip, int64_t dblocks)
 {
-	return xfs_trans_reserve_quota_nblks(NULL, ip, dblocks, 0,
-			XFS_QMOPT_RES_REGBLKS);
+	return xfs_trans_reserve_quota_nblks(NULL, ip, dblocks, 0, false);
 }
 #else
 static inline int

@@ -134,7 +133,8 @@ xfs_qm_vop_dqalloc(struct xfs_inode *ip, kuid_t kuid, kgid_t kgid,
 #define xfs_trans_apply_dquot_deltas(tp)
 #define xfs_trans_unreserve_and_mod_dquots(tp)
 static inline int xfs_trans_reserve_quota_nblks(struct xfs_trans *tp,
-		struct xfs_inode *ip, int64_t nblks, long ninos, uint flags)
+		struct xfs_inode *ip, int64_t dblocks, int64_t rblocks,
+		bool force)
 {
 	return 0;
 }

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 15435229bc1f..0778b5810c26 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c

@@ -398,8 +398,7 @@ xfs_reflink_allocate_cow(
 		goto convert;
 	}
 
-	error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0,
-			XFS_QMOPT_RES_REGBLKS);
+	error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0, false);
 	if (error)
 		goto out_trans_cancel;
 

@@ -1090,8 +1089,7 @@ xfs_reflink_remap_extent(
 	if (!smap_real && dmap_written)
 		qres += dmap->br_blockcount;
 	if (qres > 0) {
-		error = xfs_trans_reserve_quota_nblks(tp, ip, qres, 0,
-				XFS_QMOPT_RES_REGBLKS);
+		error = xfs_trans_reserve_quota_nblks(tp, ip, qres, 0, false);
 		if (error)
 			goto out_cancel;
 	}

diff --git a/fs/xfs/xfs_trans_dquot.c b/fs/xfs/xfs_trans_dquot.c
index 22aa875b84f7..a1a72b7900c5 100644
--- a/fs/xfs/xfs_trans_dquot.c
+++ b/fs/xfs/xfs_trans_dquot.c

@@ -780,28 +780,42 @@ int
 xfs_trans_reserve_quota_nblks(
 	struct xfs_trans	*tp,
 	struct xfs_inode	*ip,
-	int64_t			nblks,
-	long			ninos,
-	uint			flags)
+	int64_t			dblocks,
+	int64_t			rblocks,
+	bool			force)
 {
 	struct xfs_mount	*mp = ip->i_mount;
+	unsigned int		qflags = 0;
+	int			error;
 
 	if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
 		return 0;
 
 	ASSERT(!xfs_is_quota_inode(&mp->m_sb, ip->i_ino));
-
 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
-	ASSERT((flags & ~(XFS_QMOPT_FORCE_RES)) == XFS_TRANS_DQ_RES_RTBLKS ||
-	       (flags & ~(XFS_QMOPT_FORCE_RES)) == XFS_TRANS_DQ_RES_BLKS);
-
-	/*
-	 * Reserve nblks against these dquots, with trans as the mediator.
-	 */
-	return xfs_trans_reserve_quota_bydquots(tp, mp,
-						ip->i_udquot, ip->i_gdquot,
-						ip->i_pdquot,
-						nblks, ninos, flags);
+
+	if (force)
+		qflags |= XFS_QMOPT_FORCE_RES;
+
+	/* Reserve data device quota against the inode's dquots. */
+	error = xfs_trans_reserve_quota_bydquots(tp, mp, ip->i_udquot,
+			ip->i_gdquot, ip->i_pdquot, dblocks, 0,
+			XFS_QMOPT_RES_REGBLKS | qflags);
+	if (error)
+		return error;
+
+	/* Do the same but for realtime blocks. */
+	error = xfs_trans_reserve_quota_bydquots(tp, mp, ip->i_udquot,
+			ip->i_gdquot, ip->i_pdquot, rblocks, 0,
+			XFS_QMOPT_RES_RTBLKS | qflags);
+	if (error) {
+		xfs_trans_reserve_quota_bydquots(tp, mp, ip->i_udquot,
+				ip->i_gdquot, ip->i_pdquot, -dblocks, 0,
+				XFS_QMOPT_RES_REGBLKS);
+		return error;
+	}
+
+	return 0;
 }
 
 /* Change the quota reservations for an inode creation activity. */