[093/115] xfs: make xfs_bmapi_convert_delalloc() to allocate the target offset

Commit Message

Darrick J. Wong July 30, 2024, 12:48 a.m. UTC

From: Zhang Yi <[e-mail]>

Source kernel commit: 2e08371a83f1c06fd85eea8cd37c87a224cc4cc4

Since xfs_bmapi_convert_delalloc() only attempts to allocate the entire
delalloc extent and require multiple invocations to allocate the target
offset. So xfs_convert_blocks() add a loop to do this job and we call it
in the write back path, but xfs_convert_blocks() isn't a common helper.
Let's do it in xfs_bmapi_convert_delalloc() and drop
xfs_convert_blocks(), preparing for the post EOF delalloc blocks
converting in the buffered write begin path.

Signed-off-by: Zhang Yi <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
Reviewed-by: "Darrick J. Wong" <[e-mail]>
Signed-off-by: Chandan Babu R <[e-mail]>
---
 libxfs/libxfs_priv.h |    5 ++++-
 libxfs/xfs_bmap.c    |   34 ++++++++++++++++++++++++++++++++--
 2 files changed, 36 insertions(+), 3 deletions(-)

Patch

diff --git a/libxfs/libxfs_priv.h b/libxfs/libxfs_priv.h
index 023444082..90b2db091 100644
--- a/libxfs/libxfs_priv.h
+++ b/libxfs/libxfs_priv.h
@@ -79,7 +79,10 @@  extern struct kmem_cache *xfs_trans_cache;
 #define crc32c(c,p,l)	crc32c_le((c),(unsigned char const *)(p),(l))
 
 /* fake up kernel's iomap, (not) used in xfs_bmap.[ch] */
-struct iomap;
+struct iomap {
+	unsigned long long	offset;	/* do not use */
+	unsigned long long	length;	/* do not use */
+};
 
 #define cancel_delayed_work_sync(work) do { } while(0)
 
diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c
index 33d0764a0..9fce05e1f 100644
--- a/libxfs/xfs_bmap.c
+++ b/libxfs/xfs_bmap.c
@@ -4584,8 +4584,8 @@  xfs_bmapi_write(
  * invocations to allocate the target offset if a large enough physical extent
  * is not available.
  */
-int
-xfs_bmapi_convert_delalloc(
+static int
+xfs_bmapi_convert_one_delalloc(
 	struct xfs_inode	*ip,
 	int			whichfork,
 	xfs_off_t		offset,
@@ -4718,6 +4718,36 @@  xfs_bmapi_convert_delalloc(
 	return error;
 }
 
+/*
+ * Pass in a dellalloc extent and convert it to real extents, return the real
+ * extent that maps offset_fsb in iomap.
+ */
+int
+xfs_bmapi_convert_delalloc(
+	struct xfs_inode	*ip,
+	int			whichfork,
+	loff_t			offset,
+	struct iomap		*iomap,
+	unsigned int		*seq)
+{
+	int			error;
+
+	/*
+	 * Attempt to allocate whatever delalloc extent currently backs offset
+	 * and put the result into iomap.  Allocate in a loop because it may
+	 * take several attempts to allocate real blocks for a contiguous
+	 * delalloc extent if free space is sufficiently fragmented.
+	 */
+	do {
+		error = xfs_bmapi_convert_one_delalloc(ip, whichfork, offset,
+					iomap, seq);
+		if (error)
+			return error;
+	} while (iomap->offset + iomap->length <= offset);
+
+	return 0;
+}
+
 int
 xfs_bmapi_remap(
 	struct xfs_trans	*tp,