return false;
}
+/*
+ * Allocate & map buffers for page given the extent map. Write it out.
+ * except for the original page of a writepage, this is called on
+ * delalloc/unwritten pages only, for the original page it is possible
+ * that the page has no mapping at all.
+ */
+STATIC int
+xfs_convert_page(
+ struct inode *inode,
+ struct page *page,
+ loff_t tindex,
+ struct xfs_writepage_ctx *wpc,
+ struct writeback_control *wbc)
+{
+ struct buffer_head *bh, *head;
+ xfs_off_t end_offset;
+ unsigned long p_offset;
+ int len, page_dirty;
+ int count = 0, done = 0, uptodate = 1;
+ xfs_off_t offset = page_offset(page);
+
+ if (page->index != tindex)
+ goto fail;
+ if (!trylock_page(page))
+ goto fail;
+ if (PageWriteback(page))
+ goto fail_unlock_page;
+ if (page->mapping != inode->i_mapping)
+ goto fail_unlock_page;
+ if (!xfs_check_page_type(page, wpc->ioend->io_type, false))
+ goto fail_unlock_page;
+
+ /*
+ * page_dirty is initially a count of buffers on the page before
+ * EOF and is decremented 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));
+
+ /*
+ * If the current map does not span the entire page we are about to try
+ * to write, then give up. The only way we can write a page that spans
+ * multiple mappings in a single writeback iteration is via the
+ * xfs_vm_writepage() function. Data integrity writeback requires the
+ * entire page to be written in a single attempt, otherwise the part of
+ * the page we don't write here doesn't get written as part of the data
+ * integrity sync.
+ *
+ * For normal writeback, we also don't attempt to write partial pages
+ * here as it simply means that write_cache_pages() will see it under
+ * writeback and ignore the page until some point in the future, at
+ * which time this will be the only page in the file that needs
+ * writeback. Hence for more optimal IO patterns, we should always
+ * avoid partial page writeback due to multiple mappings on a page here.
+ */
+ if (!xfs_imap_valid(inode, &wpc->imap, end_offset))
+ goto fail_unlock_page;
+
+ len = 1 << inode->i_blkbits;
+ 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;
+
+ /*
+ * The moment we find a buffer that doesn't match our current type
+ * specification or can't be written, abort the loop and start
+ * writeback. As per the above xfs_imap_valid() check, only
+ * xfs_vm_writepage() can handle partial page writeback fully - we are
+ * limited here to the buffers that are contiguous with the current
+ * ioend, and hence a buffer we can't write breaks that contiguity and
+ * we have to defer the rest of the IO to xfs_vm_writepage().
+ */
+ bh = head = page_buffers(page);
+ do {
+ if (offset >= end_offset)
+ break;
+ if (!buffer_uptodate(bh))
+ uptodate = 0;
+ if (!(PageUptodate(page) || buffer_uptodate(bh))) {
+ done = 1;
+ break;
+ }
+
+ if (buffer_unwritten(bh) || buffer_delay(bh) ||
+ buffer_mapped(bh)) {
+ if (buffer_unwritten(bh))
+ wpc->io_type = XFS_IO_UNWRITTEN;
+ else if (buffer_delay(bh))
+ wpc->io_type = XFS_IO_DELALLOC;
+ else
+ wpc->io_type = XFS_IO_OVERWRITE;
+
+ /*
+ * imap should always be valid because of the above
+ * partial page end_offset check on the imap.
+ */
+ ASSERT(xfs_imap_valid(inode, &wpc->imap, offset));
+
+ lock_buffer(bh);
+ if (wpc->io_type != XFS_IO_OVERWRITE)
+ xfs_map_at_offset(inode, bh, &wpc->imap, offset);
+ xfs_add_to_ioend(inode, bh, offset, wpc);
+
+ page_dirty--;
+ count++;
+ } else {
+ done = 1;
+ break;
+ }
+ } while (offset += len, (bh = bh->b_this_page) != head);
+
+ if (uptodate && bh == head)
+ SetPageUptodate(page);
+
+ if (count) {
+ if (--wbc->nr_to_write <= 0 &&
+ wbc->sync_mode == WB_SYNC_NONE)
+ done = 1;
+ }
+ xfs_start_page_writeback(page, !page_dirty, count);
+
+ return done;
+ fail_unlock_page:
+ unlock_page(page);
+ fail:
+ return 1;
+}
+
+/*
+ * Convert & write out a cluster of pages in the same extent as defined
+ * by mp and following the start page.
+ */
+STATIC void
+xfs_cluster_write(
+ struct inode *inode,
+ pgoff_t tindex,
+ struct xfs_writepage_ctx *wpc,
+ struct writeback_control *wbc,
+ pgoff_t tlast)
+{
+ struct pagevec pvec;
+ int done = 0, i;
+
+ pagevec_init(&pvec, 0);
+ while (!done && tindex <= tlast) {
+ unsigned len = min_t(pgoff_t, PAGEVEC_SIZE, tlast - tindex + 1);
+
+ if (!pagevec_lookup(&pvec, inode->i_mapping, tindex, len))
+ break;
+
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ done = xfs_convert_page(inode, pvec.pages[i], tindex++,
+ wpc, wbc);
+ if (done)
+ break;
+ }
+
+ pagevec_release(&pvec);
+ cond_resched();
+ }
+}
+
STATIC void
xfs_vm_invalidatepage(
struct page *page,
struct buffer_head *bh, *head;
loff_t offset;
__uint64_t end_offset;
- pgoff_t end_index;
+ pgoff_t end_index, last_index;
ssize_t len;
int err, uptodate = 1;
int count = 0;
if (WARN_ON_ONCE(current->flags & PF_FSTRANS))
goto redirty;
+ /* Is this page beyond the end of the file? */
+ offset = i_size_read(inode);
+ end_index = offset >> PAGE_CACHE_SHIFT;
+ last_index = (offset - 1) >> PAGE_CACHE_SHIFT;
+
/*
- * Is this page beyond the end of the file?
- *
* The page index is less than the end_index, adjust the end_offset
* to the highest offset that this page should represent.
* -----------------------------------------------------
* | desired writeback range | see else |
* ---------------------------------^------------------|
*/
- offset = i_size_read(inode);
- end_index = offset >> PAGE_CACHE_SHIFT;
if (page->index < end_index)
end_offset = (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT;
else {
xfs_start_page_writeback(page, 1, count);
- ASSERT(wpc->iohead || !count);
+ /* if there is no IO to be submitted for this page, we are done */
+ if (!count)
+ return 0;
+
+ ASSERT(wpc->iohead);
+ ASSERT(err == 0);
+
+ /*
+ * Any errors from this point onwards need tobe reported through the IO
+ * completion path as we have marked the initial page as under writeback
+ * and unlocked it.
+ */
+ if (wpc->imap_valid) {
+ xfs_off_t end_index;
+
+ end_index = wpc->imap.br_startoff + wpc->imap.br_blockcount;
+
+ /* to bytes */
+ end_index <<= inode->i_blkbits;
+
+ /* to pages */
+ end_index = (end_index - 1) >> PAGE_CACHE_SHIFT;
+
+ /* check against file size */
+ if (end_index > last_index)
+ end_index = last_index;
+
+ xfs_cluster_write(inode, page->index + 1, wpc, wbc, end_index);
+ }
return 0;
error:
projects / users / jedix / linux-maple.git / commitdiff