From d1afb678ce77b930334a8a640a05b8e68178a377 Mon Sep 17 00:00:00 2001 From: Lachlan McIlroy Date: Tue, 27 Nov 2007 17:01:24 +1100 Subject: [PATCH] [XFS] Fixed a few bugs in xfs_buf_associate_memory() - calculation of 'page_count' was incorrect as it did not consider the offset of 'mem' into the first page. The logic to bump 'page_count' didn't work if 'len' was <= PAGE_CACHE_SIZE (ie offset = 3k, len = 2k). - setting b_buffer_length to 'len' is incorrect if 'offset' is > 0. Set it to the total length of the buffer. - I suspect that passing a non-aligned address into mem_to_page() for the first page may have been causing issues - don't know but just tidy up that code anyway. SGI-PV: 971596 SGI-Modid: xfs-linux-melb:xfs-kern:30143a Signed-off-by: Lachlan McIlroy Signed-off-by: Christoph Hellwig --- fs/xfs/linux-2.6/xfs_buf.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index b9c8589e05c..48bf477cbca 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -725,15 +725,15 @@ xfs_buf_associate_memory( { int rval; int i = 0; - size_t ptr; - size_t end, end_cur; - off_t offset; + unsigned long pageaddr; + unsigned long offset; + size_t buflen; int page_count; - page_count = PAGE_CACHE_ALIGN(len) >> PAGE_CACHE_SHIFT; - offset = (off_t) mem - ((off_t)mem & PAGE_CACHE_MASK); - if (offset && (len > PAGE_CACHE_SIZE)) - page_count++; + pageaddr = (unsigned long)mem & PAGE_CACHE_MASK; + offset = (unsigned long)mem - pageaddr; + buflen = PAGE_CACHE_ALIGN(len + offset); + page_count = buflen >> PAGE_CACHE_SHIFT; /* Free any previous set of page pointers */ if (bp->b_pages) @@ -747,22 +747,15 @@ xfs_buf_associate_memory( return rval; bp->b_offset = offset; - ptr = (size_t) mem & PAGE_CACHE_MASK; - end = PAGE_CACHE_ALIGN((size_t) mem + len); - end_cur = end; - /* set up first page */ - bp->b_pages[0] = mem_to_page(mem); - - ptr += PAGE_CACHE_SIZE; - bp->b_page_count = ++i; - while (ptr < end) { - bp->b_pages[i] = mem_to_page((void *)ptr); - bp->b_page_count = ++i; - ptr += PAGE_CACHE_SIZE; + + for (i = 0; i < bp->b_page_count; i++) { + bp->b_pages[i] = mem_to_page((void *)pageaddr); + pageaddr += PAGE_CACHE_SIZE; } bp->b_locked = 0; - bp->b_count_desired = bp->b_buffer_length = len; + bp->b_count_desired = len; + bp->b_buffer_length = buflen; bp->b_flags |= XBF_MAPPED; return 0; -- 2.41.1