Ejemplo n.º 1
0
STATIC ssize_t
xfs_file_buffered_aio_write(
	struct kiocb		*iocb,
	struct iov_iter		*from)
{
	struct file		*file = iocb->ki_filp;
	struct address_space	*mapping = file->f_mapping;
	struct inode		*inode = mapping->host;
	struct xfs_inode	*ip = XFS_I(inode);
	ssize_t			ret;
	int			enospc = 0;
	int			iolock;

	if (iocb->ki_flags & IOCB_NOWAIT)
		return -EOPNOTSUPP;

write_retry:
	iolock = XFS_IOLOCK_EXCL;
	xfs_ilock(ip, iolock);

	ret = xfs_file_aio_write_checks(iocb, from, &iolock);
	if (ret)
		goto out;

	/* We can write back this queue in page reclaim */
	current->backing_dev_info = inode_to_bdi(inode);

	trace_xfs_file_buffered_write(ip, iov_iter_count(from), iocb->ki_pos);
	ret = iomap_file_buffered_write(iocb, from, &xfs_iomap_ops);
	if (likely(ret >= 0))
		iocb->ki_pos += ret;

	/*
	 * If we hit a space limit, try to free up some lingering preallocated
	 * space before returning an error. In the case of ENOSPC, first try to
	 * write back all dirty inodes to free up some of the excess reserved
	 * metadata space. This reduces the chances that the eofblocks scan
	 * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
	 * also behaves as a filter to prevent too many eofblocks scans from
	 * running at the same time.
	 */
	if (ret == -EDQUOT && !enospc) {
		xfs_iunlock(ip, iolock);
		enospc = xfs_inode_free_quota_eofblocks(ip);
		if (enospc)
			goto write_retry;
		enospc = xfs_inode_free_quota_cowblocks(ip);
		if (enospc)
			goto write_retry;
		iolock = 0;
	} else if (ret == -ENOSPC && !enospc) {
		struct xfs_eofblocks eofb = {0};

		enospc = 1;
		xfs_flush_inodes(ip->i_mount);

		xfs_iunlock(ip, iolock);
		eofb.eof_flags = XFS_EOF_FLAGS_SYNC;
		xfs_icache_free_eofblocks(ip->i_mount, &eofb);
		xfs_icache_free_cowblocks(ip->i_mount, &eofb);
		goto write_retry;
	}

	current->backing_dev_info = NULL;
out:
	if (iolock)
		xfs_iunlock(ip, iolock);
	return ret;
}
Ejemplo n.º 2
0
static int gfs2_write_jdata_pagevec(struct address_space *mapping,
				    struct writeback_control *wbc,
				    struct pagevec *pvec,
				    int nr_pages, pgoff_t end,
				    pgoff_t *done_index)
{
	struct inode *inode = mapping->host;
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	unsigned nrblocks = nr_pages * (PAGE_CACHE_SIZE/inode->i_sb->s_blocksize);
	int i;
	int ret;

	ret = gfs2_trans_begin(sdp, nrblocks, nrblocks);
	if (ret < 0)
		return ret;

	for(i = 0; i < nr_pages; i++) {
		struct page *page = pvec->pages[i];

		/*
		 * At this point, the page may be truncated or
		 * invalidated (changing page->mapping to NULL), or
		 * even swizzled back from swapper_space to tmpfs file
		 * mapping. However, page->index will not change
		 * because we have a reference on the page.
		 */
		if (page->index > end) {
			/*
			 * can't be range_cyclic (1st pass) because
			 * end == -1 in that case.
			 */
			ret = 1;
			break;
		}

		*done_index = page->index;

		lock_page(page);

		if (unlikely(page->mapping != mapping)) {
continue_unlock:
			unlock_page(page);
			continue;
		}

		if (!PageDirty(page)) {
			/* someone wrote it for us */
			goto continue_unlock;
		}

		if (PageWriteback(page)) {
			if (wbc->sync_mode != WB_SYNC_NONE)
				wait_on_page_writeback(page);
			else
				goto continue_unlock;
		}

		BUG_ON(PageWriteback(page));
		if (!clear_page_dirty_for_io(page))
			goto continue_unlock;

		trace_wbc_writepage(wbc, inode_to_bdi(inode));

		ret = __gfs2_jdata_writepage(page, wbc);
		if (unlikely(ret)) {
			if (ret == AOP_WRITEPAGE_ACTIVATE) {
				unlock_page(page);
				ret = 0;
			} else {

				/*
				 * done_index is set past this page,
				 * so media errors will not choke
				 * background writeout for the entire
				 * file. This has consequences for
				 * range_cyclic semantics (ie. it may
				 * not be suitable for data integrity
				 * writeout).
				 */
				*done_index = page->index + 1;
				ret = 1;
				break;
			}
		}

		/*
		 * We stop writing back only if we are not doing
		 * integrity sync. In case of integrity sync we have to
		 * keep going until we have written all the pages
		 * we tagged for writeback prior to entering this loop.
		 */
		if (--wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) {
			ret = 1;
			break;
		}

	}
	gfs2_trans_end(sdp);
	return ret;
}