From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id qASMOp0o218575 for ; Wed, 28 Nov 2012 16:24:51 -0600 Received: from eagdhcp-232-125.americas.sgi.com (eagdhcp-232-125.americas.sgi.com [128.162.232.125]) by relay3.corp.sgi.com (Postfix) with ESMTP id DE2E2AC004 for ; Wed, 28 Nov 2012 14:27:05 -0800 (PST) Received: from eagdhcp-232-125.americas.sgi.com (localhost [127.0.0.1]) by eagdhcp-232-125.americas.sgi.com (8.14.5/8.14.5) with ESMTP id qASMR6J5003587 for ; Wed, 28 Nov 2012 16:27:06 -0600 (CST) (envelope-from tinguely@sgi.com) Message-Id: <20121128222622.688093599@sgi.com> Date: Wed, 28 Nov 2012 16:23:10 -0600 From: Mark Tinguely Subject: [PATCH v2 1/3] xfs: use b_maps[] for discontiguous buffers References: <20121128222309.109033307@.sgi.com> Content-Disposition: inline; filename=1-3-xfs-use-xfs_buf-b_maps.patch List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Commits starting at 77c1a08 introduced a multiple segment support to xfs_buf. xfs_trans_buf_item_match() could not find a multi-segment buffer in the transaction because it was looking at the single segment block number rather than the multi-segment b_maps[0].bm.bn. This results on a recursive buffer lock that can never be satisfied. This patch: 1) Changed the remaining b_map accesses to be b_maps[0] accesses. 2) Renames the single segment b_map structure to __b_map to avoid future confusion. Signed-off-by: Mark Tinguely --- fs/xfs/xfs_buf.c | 12 ++++++------ fs/xfs/xfs_buf.h | 6 +++--- 2 files changed, 9 insertions(+), 9 deletions(-) Index: b/fs/xfs/xfs_buf.c =================================================================== --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -175,7 +175,7 @@ xfs_buf_get_maps( bp->b_map_count = map_count; if (map_count == 1) { - bp->b_maps = &bp->b_map; + bp->b_maps = &bp->__b_map; return 0; } @@ -193,7 +193,7 @@ static void xfs_buf_free_maps( struct xfs_buf *bp) { - if (bp->b_maps != &bp->b_map) { + if (bp->b_maps != &bp->__b_map) { kmem_free(bp->b_maps); bp->b_maps = NULL; } @@ -377,8 +377,8 @@ xfs_buf_allocate_memory( } use_alloc_page: - start = BBTOB(bp->b_map.bm_bn) >> PAGE_SHIFT; - end = (BBTOB(bp->b_map.bm_bn + bp->b_length) + PAGE_SIZE - 1) + 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, flags); @@ -640,7 +640,7 @@ _xfs_buf_read( xfs_buf_flags_t flags) { ASSERT(!(flags & XBF_WRITE)); - ASSERT(bp->b_map.bm_bn != XFS_BUF_DADDR_NULL); + ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL); bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD); bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); @@ -1709,7 +1709,7 @@ xfs_buf_cmp( struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); xfs_daddr_t diff; - diff = ap->b_map.bm_bn - bp->b_map.bm_bn; + diff = ap->b_maps[0].bm_bn - bp->b_maps[0].bm_bn; if (diff < 0) return -1; if (diff > 0) Index: b/fs/xfs/xfs_buf.h =================================================================== --- a/fs/xfs/xfs_buf.h +++ b/fs/xfs/xfs_buf.h @@ -151,7 +151,7 @@ typedef struct xfs_buf { struct page **b_pages; /* array of page pointers */ struct page *b_page_array[XB_PAGES]; /* inline pages */ struct xfs_buf_map *b_maps; /* compound buffer map */ - struct xfs_buf_map b_map; /* inline compound buffer map */ + struct xfs_buf_map __b_map; /* inline compound buffer map */ int b_map_count; int b_io_length; /* IO size in BBs */ atomic_t b_pin_count; /* pin count */ @@ -330,8 +330,8 @@ void xfs_buf_stale(struct xfs_buf *bp); * In future, uncached buffers will pass the block number directly to the io * request function and hence these macros will go away at that point. */ -#define XFS_BUF_ADDR(bp) ((bp)->b_map.bm_bn) -#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_map.bm_bn = (xfs_daddr_t)(bno)) +#define XFS_BUF_ADDR(bp) ((bp)->b_maps[0].bm_bn) +#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno)) static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref) { _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs