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authorLachlan McIlroy <lachlan@sgi.com>2007-11-27 17:01:24 +1100
committerLachlan McIlroy <lachlan@redback.melbourne.sgi.com>2007-12-10 13:46:20 +1100
commitd1afb678ce77b930334a8a640a05b8e68178a377 (patch)
tree155f925fa5fca75e445e10611b3fbe12cfad09f4 /fs/xfs/linux-2.6/xfs_buf.c
parentcd57e594adc624dd9ee4c0ded3949da21ec24b2f (diff)
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[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 <lachlan@sgi.com> Signed-off-by: Christoph Hellwig <hch@infradead.org>
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_buf.c')
-rw-r--r--fs/xfs/linux-2.6/xfs_buf.c33
1 files 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 b9c8589e05c2..48bf477cbca5 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;