From a19fb380961f209a3a406443686647bcd01bb9a6 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Sat, 26 Mar 2011 09:13:42 +1100 Subject: [PATCH] vmap: flush vmap aliases when mapping fails On 32 bit systems, vmalloc space is limited and XFS can chew through it quickly as the vmalloc space is lazily freed. This can result in failure to map buffers, even when there is apparently large amounts of vmalloc space available. Hence, if we fail to map a buffer, purge the aliases that have not yet been freed to hopefuly free up enough vmalloc space to allow a retry to succeed. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Reviewed-by: Alex Elder --- fs/xfs/linux-2.6/xfs_buf.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index 3cc671c8a67..a5a260fab82 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -455,9 +455,17 @@ _xfs_buf_map_pages( bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset; bp->b_flags |= XBF_MAPPED; } else if (flags & XBF_MAPPED) { - bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, - -1, PAGE_KERNEL); - if (unlikely(bp->b_addr == NULL)) + int retried = 0; + + do { + bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, + -1, PAGE_KERNEL); + if (bp->b_addr) + break; + vm_unmap_aliases(); + } while (retried++ <= 1); + + if (!bp->b_addr) return -ENOMEM; bp->b_addr += bp->b_offset; bp->b_flags |= XBF_MAPPED; -- 2.11.4.GIT