[XFS] various fixes for xfs_convert_page fix various bogusities in
handling offets From David Chinner and Christoph Hellwig
SGI-PV: 947118
SGI-Modid: xfs-linux-melb:xfs-kern:203826a
Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index b306e25..64c909e 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -624,12 +624,13 @@
int all_bh)
{
struct buffer_head *bh, *head;
- unsigned long p_offset, end_offset;
+ xfs_off_t end_offset;
+ unsigned long p_offset;
unsigned int type;
int bbits = inode->i_blkbits;
int len, page_dirty;
int count = 0, done = 0, uptodate = 1;
- xfs_off_t f_offset = page_offset(page);
+ xfs_off_t offset = page_offset(page);
if (page->index != tindex)
goto fail;
@@ -642,21 +643,33 @@
if (!xfs_is_delayed_page(page, (*ioendp)->io_type))
goto fail_unlock_page;
- end_offset = (i_size_read(inode) & (PAGE_CACHE_SIZE - 1));
-
/*
* page_dirty is initially a count of buffers on the page before
* EOF and is decrememted as we move each into a cleanable state.
+ *
+ * Derivation:
+ *
+ * End offset is the highest offset that this page should represent.
+ * If we are on the last page, (end_offset & (PAGE_CACHE_SIZE - 1))
+ * will evaluate non-zero and be less than PAGE_CACHE_SIZE and
+ * hence give us the correct page_dirty count. On any other page,
+ * it will be zero and in that case we need page_dirty to be the
+ * count of buffers on the page.
*/
+ end_offset = min_t(unsigned long long,
+ (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT,
+ i_size_read(inode));
+
len = 1 << inode->i_blkbits;
- end_offset = max(end_offset, PAGE_CACHE_SIZE);
- end_offset = roundup(end_offset, len);
- page_dirty = end_offset / len;
+ p_offset = min_t(unsigned long, end_offset & (PAGE_CACHE_SIZE - 1),
+ PAGE_CACHE_SIZE);
+ p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE;
+ page_dirty = p_offset / len;
p_offset = 0;
bh = head = page_buffers(page);
do {
- if (p_offset >= end_offset)
+ if (offset >= end_offset)
break;
if (!buffer_uptodate(bh))
uptodate = 0;
@@ -665,43 +678,45 @@
continue;
}
- if (buffer_unwritten(bh))
- type = IOMAP_UNWRITTEN;
- else if (buffer_delay(bh))
- type = IOMAP_DELAY;
- else {
- type = 0;
- if (!(buffer_mapped(bh) && all_bh && startio)) {
+ if (buffer_unwritten(bh) || buffer_delay(bh)) {
+ if (buffer_unwritten(bh))
+ type = IOMAP_UNWRITTEN;
+ else
+ type = IOMAP_DELAY;
+
+ if (!xfs_iomap_valid(mp, offset)) {
done = 1;
- } else if (startio) {
+ continue;
+ }
+
+ ASSERT(!(mp->iomap_flags & IOMAP_HOLE));
+ ASSERT(!(mp->iomap_flags & IOMAP_DELAY));
+
+ xfs_map_at_offset(bh, offset, bbits, mp);
+ if (startio) {
+ xfs_add_to_ioend(inode, bh, p_offset,
+ type, ioendp, done);
+ } else {
+ set_buffer_dirty(bh);
+ unlock_buffer(bh);
+ mark_buffer_dirty(bh);
+ }
+ page_dirty--;
+ count++;
+ } else {
+ type = 0;
+ if (buffer_mapped(bh) && all_bh && startio) {
lock_buffer(bh);
xfs_add_to_ioend(inode, bh, p_offset,
type, ioendp, done);
count++;
page_dirty--;
+ } else {
+ done = 1;
}
- continue;
}
-
- if (!xfs_iomap_valid(mp, f_offset + p_offset)) {
- done = 1;
- continue;
- }
- ASSERT(!(mp->iomap_flags & IOMAP_HOLE));
- ASSERT(!(mp->iomap_flags & IOMAP_DELAY));
-
- xfs_map_at_offset(bh, f_offset + p_offset, bbits, mp);
- if (startio) {
- xfs_add_to_ioend(inode, bh, p_offset,
- type, ioendp, done);
- count++;
- } else {
- set_buffer_dirty(bh);
- unlock_buffer(bh);
- mark_buffer_dirty(bh);
- }
- page_dirty--;
- } while (p_offset += len, (bh = bh->b_this_page) != head);
+ } while (offset += len, p_offset += len,
+ (bh = bh->b_this_page) != head);
if (uptodate && bh == head)
SetPageUptodate(page);