From 611c99468c7aa1a5c2bb6d46e7b5d8e53eecfefd Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 23 Apr 2012 15:59:07 +1000 Subject: xfs: make XBF_MAPPED the default behaviour Rather than specifying XBF_MAPPED for almost all buffers, introduce XBF_UNMAPPED for the couple of users that use unmapped buffers. Signed-off-by: Dave Chinner Reviewed-by: Mark Tinguely Reviewed-by: Christoph Hellwig Signed-off-by: Ben Myers --- fs/xfs/xfs_buf.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) (limited to 'fs/xfs/xfs_buf.c') diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index b2795bab1a0..172d3cc8f8c 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -65,11 +65,11 @@ xfs_buf_is_vmapped( /* * Return true if the buffer is vmapped. * - * The XBF_MAPPED flag is set if the buffer should be mapped, but the - * code is clever enough to know it doesn't have to map a single page, - * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1. + * b_addr is null if the buffer is not mapped, but the code is clever + * enough to know it doesn't have to map a single page, so the check has + * to be both for b_addr and bp->b_page_count > 1. */ - return (bp->b_flags & XBF_MAPPED) && bp->b_page_count > 1; + return bp->b_addr && bp->b_page_count > 1; } static inline int @@ -181,7 +181,7 @@ xfs_buf_alloc( * We don't want certain flags to appear in b_flags unless they are * specifically set by later operations on the buffer. */ - flags &= ~(XBF_MAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD); + flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD); atomic_set(&bp->b_hold, 1); atomic_set(&bp->b_lru_ref, 1); @@ -329,7 +329,7 @@ xfs_buf_allocate_memory( bp->b_pages = bp->b_page_array; bp->b_pages[0] = virt_to_page(bp->b_addr); bp->b_page_count = 1; - bp->b_flags |= XBF_MAPPED | _XBF_KMEM; + bp->b_flags |= _XBF_KMEM; return 0; } @@ -399,8 +399,9 @@ _xfs_buf_map_pages( if (bp->b_page_count == 1) { /* A single page buffer is always mappable */ bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; - bp->b_flags |= XBF_MAPPED; - } else if (flags & XBF_MAPPED) { + } else if (flags & XBF_UNMAPPED) { + bp->b_addr = NULL; + } else { int retried = 0; do { @@ -414,7 +415,6 @@ _xfs_buf_map_pages( if (!bp->b_addr) return -ENOMEM; bp->b_addr += bp->b_offset; - bp->b_flags |= XBF_MAPPED; } return 0; @@ -520,7 +520,7 @@ found: */ if (bp->b_flags & XBF_STALE) { ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0); - bp->b_flags &= XBF_MAPPED | _XBF_KMEM | _XBF_PAGES; + bp->b_flags &= _XBF_KMEM | _XBF_PAGES; } trace_xfs_buf_find(bp, flags, _RET_IP_); @@ -575,7 +575,7 @@ xfs_buf_get( bp->b_io_length = bp->b_length; found: - if (!(bp->b_flags & XBF_MAPPED)) { + if (!bp->b_addr) { error = _xfs_buf_map_pages(bp, flags); if (unlikely(error)) { xfs_warn(target->bt_mount, @@ -707,7 +707,6 @@ xfs_buf_set_empty( bp->b_length = numblks; bp->b_io_length = numblks; bp->b_bn = XFS_BUF_DADDR_NULL; - bp->b_flags &= ~XBF_MAPPED; } static inline struct page * @@ -759,7 +758,6 @@ xfs_buf_associate_memory( bp->b_io_length = BTOBB(len); bp->b_length = BTOBB(buflen); - bp->b_flags |= XBF_MAPPED; return 0; } @@ -790,7 +788,7 @@ xfs_buf_get_uncached( } bp->b_flags |= _XBF_PAGES; - error = _xfs_buf_map_pages(bp, XBF_MAPPED); + error = _xfs_buf_map_pages(bp, 0); if (unlikely(error)) { xfs_warn(target->bt_mount, "%s: failed to map pages\n", __func__); @@ -1287,7 +1285,7 @@ xfs_buf_offset( { struct page *page; - if (bp->b_flags & XBF_MAPPED) + if (bp->b_addr) return bp->b_addr + offset; offset += bp->b_offset; -- cgit v1.2.3