[PATCH 07/11] xfs: simplify the b_page_count calculation
From: Christoph Hellwig <hch@lst.de>
Date: 2021-05-19 19:09:34
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
Ever since we stopped using the Linux page cache to back XFS buffes there is no need to take the start sector into account for calculating the number of pages in a buffer, as the data always start from the beginning of the buffer. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/xfs/xfs_buf.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 08c8667e6027fc..76a107e3cb2a22 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c@@ -278,15 +278,14 @@ _xfs_buf_alloc( */ STATIC int _xfs_buf_get_pages( - struct xfs_buf *bp, - int page_count) + struct xfs_buf *bp) { ASSERT(bp->b_pages == NULL); - bp->b_page_count = page_count; - if (page_count > XB_PAGES) { - bp->b_pages = kmem_zalloc(sizeof(struct page *) * page_count, - KM_NOFS); + bp->b_page_count = DIV_ROUND_UP(BBTOB(bp->b_length), PAGE_SIZE); + if (bp->b_page_count > XB_PAGES) { + bp->b_pages = kmem_zalloc(sizeof(struct page *) * + bp->b_page_count, KM_NOFS); if (!bp->b_pages) return -ENOMEM; } else {
@@ -384,8 +383,7 @@ xfs_buf_alloc_pages( uint flags) { gfp_t gfp_mask = xb_to_gfp(flags); - unsigned short page_count, i; - xfs_off_t start, end; + unsigned short i; int error; /*
@@ -394,11 +392,7 @@ xfs_buf_alloc_pages( if (!(flags & XBF_READ)) gfp_mask |= __GFP_ZERO; - start = BBTOB(bp->b_maps[0].bm_bn) >> PAGE_SHIFT; - end = (BBTOB(bp->b_maps[0].bm_bn + bp->b_length) + PAGE_SIZE - 1) - >> PAGE_SHIFT; - page_count = end - start; - error = _xfs_buf_get_pages(bp, page_count); + error = _xfs_buf_get_pages(bp); if (unlikely(error)) return error;
@@ -942,7 +936,6 @@ xfs_buf_get_uncached( int flags, struct xfs_buf **bpp) { - unsigned long page_count; int error, i; struct xfs_buf *bp; DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks);
@@ -954,12 +947,11 @@ xfs_buf_get_uncached( if (error) goto fail; - page_count = PAGE_ALIGN(numblks << BBSHIFT) >> PAGE_SHIFT; - error = _xfs_buf_get_pages(bp, page_count); + error = _xfs_buf_get_pages(bp); if (error) goto fail_free_buf; - for (i = 0; i < page_count; i++) { + for (i = 0; i < bp->b_page_count; i++) { bp->b_pages[i] = alloc_page(xb_to_gfp(flags)); if (!bp->b_pages[i]) { error = -ENOMEM;
--
2.30.2