[PATCH 7/9] xfs: refactor xfs_bmapi_allocate

Christoph Hellwig
2019-10-30T18:05:05Z

Avoid duplicate userdata and data fork checks by restructuring the code
so we only have a helper for userdata allocations that combines these
checks in a straight foward way. That also helps to obsoletes the
comments explaining what the code does as it is now clearly obvious.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_bmap.c | 93 +++++++++++++++++++---------------------
1 file changed, 45 insertions(+), 48 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 392a809c13e8..1e319a4830be 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -3641,20 +3641,6 @@ xfs_bmap_btalloc(
return 0;
}

-/*
- * xfs_bmap_alloc is called by xfs_bmapi to allocate an extent for a file.
- * It figures out where to ask the underlying allocator to put the new extent.
- */
-STATIC int
-xfs_bmap_alloc(
- struct xfs_bmalloca *ap) /* bmap alloc argument struct */
-{
- if (XFS_IS_REALTIME_INODE(ap->ip) &&
- xfs_alloc_is_userdata(ap->datatype))
- return xfs_bmap_rtalloc(ap);
- return xfs_bmap_btalloc(ap);
-}
-
/* Trim extent to fit a logical block range. */
void
xfs_trim_extent(
@@ -4010,6 +3996,42 @@ xfs_bmapi_reserve_delalloc(
return error;
}

+static int
+xfs_bmap_alloc_userdata(
+ struct xfs_bmalloca *bma)
+{
+ struct xfs_mount *mp = bma->ip->i_mount;
+ int whichfork = xfs_bmapi_whichfork(bma->flags);
+ int error;
+
+ /*
+ * Set the data type being allocated. For the data fork, the first data
+ * in the file is treated differently to all other allocations. For the
+ * attribute fork, we only need to ensure the allocated range is not on
+ * the busy list.
+ */
+ bma->datatype = XFS_ALLOC_NOBUSY;
+ if (bma->flags & XFS_BMAPI_ZERO)
+ bma->datatype |= XFS_ALLOC_USERDATA_ZERO;
+ if (whichfork == XFS_DATA_FORK) {
+ if (bma->offset == 0)
+ bma->datatype |= XFS_ALLOC_INITIAL_USER_DATA;
+ else
+ bma->datatype |= XFS_ALLOC_USERDATA;
+
+ if (mp->m_dalign && bma->length >= mp->m_dalign) {
+ error = xfs_bmap_isaeof(bma, whichfork);
+ if (error)
+ return error;
+ }
+
+ if (XFS_IS_REALTIME_INODE(bma->ip))
+ return xfs_bmap_rtalloc(bma);
+ }
+
+ return xfs_bmap_btalloc(bma);
+}
+
static int
xfs_bmapi_allocate(
struct xfs_bmalloca *bma)
@@ -4037,43 +4059,18 @@ xfs_bmapi_allocate(
bma->got.br_startoff - bma->offset);
}

- /*
- * Set the data type being allocated. For the data fork, the first data
- * in the file is treated differently to all other allocations. For the
- * attribute fork, we only need to ensure the allocated range is not on
- * the busy list.
- */
- if (!(bma->flags & XFS_BMAPI_METADATA)) {
- bma->datatype = XFS_ALLOC_NOBUSY;
- if (whichfork == XFS_DATA_FORK) {
- if (bma->offset == 0)
- bma->datatype |= XFS_ALLOC_INITIAL_USER_DATA;
- else
- bma->datatype |= XFS_ALLOC_USERDATA;
- }
- if (bma->flags & XFS_BMAPI_ZERO)
- bma->datatype |= XFS_ALLOC_USERDATA_ZERO;
- }
-
- bma->minlen = (bma->flags & XFS_BMAPI_CONTIG) ? bma->length : 1;
-
- /*
- * Only want to do the alignment at the eof if it is userdata and
- * allocation length is larger than a stripe unit.
- */
- if (mp->m_dalign && bma->length >= mp->m_dalign &&
- !(bma->flags & XFS_BMAPI_METADATA) && whichfork == XFS_DATA_FORK) {
- error = xfs_bmap_isaeof(bma, whichfork);
- if (error)
- return error;
- }
+ if (bma->flags & XFS_BMAPI_CONTIG)
+ bma->minlen = bma->length;
+ else
+ bma->minlen = 1;

- error = xfs_bmap_alloc(bma);
- if (error)
+ if (bma->flags & XFS_BMAPI_METADATA)
+ error = xfs_bmap_btalloc(bma);
+ else
+ error = xfs_bmap_alloc_userdata(bma);
+ if (error || bma->blkno == NULLFSBLOCK)
return error;

- if (bma->blkno == NULLFSBLOCK)
- return 0;
if ((ifp->if_flags & XFS_IFBROOT) && !bma->cur)
bma->cur = xfs_bmbt_init_cursor(mp, bma->tp, bma->ip, whichfork);
/*
--
2.20.1