[PATCH 16/15] xfs: only call xfs_setsize_buftarg once per buffer target

["Darrick J. Wong" <djwong@kernel.org>]

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

It's silly to call xfs_setsize_buftarg from xfs_alloc_buftarg with the
block device LBA size because we don't need to ask the block layer to
validate a geometry number that it provided us.  Instead, set the
preliminary bt_meta_sector* fields to the LBA size in preparation for
reading the primary super.

It's ok to lose the sync_blockdev call at buftarg creation time for the
external log and rt devices because we don't read from them until after
calling xfs_setup_devices.  We do need an explicit sync for the data
device because we read the primary super before calling
xfs_setup_devices.

This will enable the next patch to validate hw atomic write geometry
against the filesystem geometry.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
 fs/xfs/xfs_buf.h   |    5 +++++
 fs/xfs/xfs_buf.c   |    8 ++++----
 fs/xfs/xfs_super.c |    6 +++++-
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 6f691779887f77..2f809e33ec66da 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -384,6 +384,11 @@ int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops);
 bool xfs_verify_magic(struct xfs_buf *bp, __be32 dmagic);
 bool xfs_verify_magic16(struct xfs_buf *bp, __be16 dmagic);
 
+static inline int xfs_buftarg_sync(struct xfs_buftarg *btp)
+{
+	return sync_blockdev(btp->bt_bdev);
+}
+
 /* for xfs_buf_mem.c only: */
 int xfs_init_buftarg(struct xfs_buftarg *btp, size_t logical_sectorsize,
 		const char *descr);
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index c1bd5654c3afa8..437fef08b7cf7b 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1837,10 +1837,10 @@ xfs_alloc_buftarg(
 	 * When allocating the buftargs we have not yet read the super block and
 	 * thus don't know the file system sector size yet.
 	 */
-	if (xfs_setsize_buftarg(btp, bdev_logical_block_size(btp->bt_bdev)))
-		goto error_free;
-	if (xfs_init_buftarg(btp, bdev_logical_block_size(btp->bt_bdev),
-			mp->m_super->s_id))
+	btp->bt_meta_sectorsize = bdev_logical_block_size(btp->bt_bdev);
+	btp->bt_meta_sectormask = btp->bt_meta_sectorsize - 1;
+
+	if (xfs_init_buftarg(btp, btp->bt_meta_sectorsize, mp->m_super->s_id))
 		goto error_free;
 
 	return btp;
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index f021bdf8d0b592..b6b6fb4ce8ca65 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -507,7 +507,11 @@ xfs_open_devices(
 			bdev_fput(logdev_file);
 	}
 
-	return 0;
+	/*
+	 * Flush and invalidate the data device pagecache before reading the
+	 * primary super because XFS doesn't use the bdev pagecache.
+	 */
+	return xfs_buftarg_sync(mp->m_ddev_targp);
 
  out_free_rtdev_targ:
 	if (mp->m_rtdev_targp)