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| author | Lachlan McIlroy <lachlan@sgi.com> | 2007-11-27 17:01:24 +1100 |
|---|---|---|
| committer | Lachlan McIlroy <lachlan@redback.melbourne.sgi.com> | 2007-12-10 13:46:20 +1100 |
| commit | d1afb678ce77b930334a8a640a05b8e68178a377 (patch) | |
| tree | 155f925fa5fca75e445e10611b3fbe12cfad09f4 /fs/xfs | |
| parent | cd57e594adc624dd9ee4c0ded3949da21ec24b2f (diff) | |
| download | linux-d1afb678ce77b930334a8a640a05b8e68178a377.tar.bz2 | |
[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')
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_buf.c | 33 |
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; |