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Commit 8eb4efb0 authored by majianpeng's avatar majianpeng Committed by Sage Weil
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ceph: implement readv/preadv for sync operation 



For readv/preadv sync-operatoin, ceph only do the first iov.
Now implement this.

Signed-off-by: default avatarJianpeng Ma <majianpeng@gmail.com>
Reviewed-by: default avatarYan, Zheng <zheng.z.yan@intel.com>
parent e8344e66

fs/ceph/file.c

+116 −46
Original line number Diff line number Diff line
@@ -408,51 +408,92 @@ static int striped_read(struct inode *inode, 
 *

 * If the read spans object boundary, just do multiple reads.

 */

static ssize_t ceph_sync_read(struct file *file, char __user *data,

			      unsigned len, loff_t *poff, int *checkeof)

static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *i,

				int *checkeof)

{

	struct file *file = iocb->ki_filp;

	struct inode *inode = file_inode(file);

	struct page **pages;

	u64 off = *poff;

	u64 off = iocb->ki_pos;

	int num_pages, ret;

	size_t len = i->count;



	dout("sync_read on file %p %llu~%u %s\n", file, off, len,

	dout("sync_read on file %p %llu~%u %s\n", file, off,

	     (unsigned)len,

	     (file->f_flags & O_DIRECT) ? "O_DIRECT" : "");



	if (file->f_flags & O_DIRECT) {

		num_pages = calc_pages_for((unsigned long)data, len);

		pages = ceph_get_direct_page_vector(data, num_pages, true);

	} else {

		num_pages = calc_pages_for(off, len);

		pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);

	}

	if (IS_ERR(pages))

		return PTR_ERR(pages);



	/*

	 * flush any page cache pages in this range.  this

	 * will make concurrent normal and sync io slow,

	 * but it will at least behave sensibly when they are

	 * in sequence.

	 */

	ret = filemap_write_and_wait(inode->i_mapping);

	ret = filemap_write_and_wait_range(inode->i_mapping, off,

						off + len);

	if (ret < 0)

		goto done;

		return ret;



	ret = striped_read(inode, off, len, pages, num_pages, checkeof,

			   file->f_flags & O_DIRECT,

			   (unsigned long)data & ~PAGE_MASK);

	if (file->f_flags & O_DIRECT) {

		while (iov_iter_count(i)) {

			void __user *data = i->iov[0].iov_base + i->iov_offset;

			size_t len = i->iov[0].iov_len - i->iov_offset;



	if (ret >= 0 && (file->f_flags & O_DIRECT) == 0)

		ret = ceph_copy_page_vector_to_user(pages, data, off, ret);

	if (ret >= 0)

		*poff = off + ret;

			num_pages = calc_pages_for((unsigned long)data, len);

			pages = ceph_get_direct_page_vector(data,

							    num_pages, true);

			if (IS_ERR(pages))

				return PTR_ERR(pages);



done:

	if (file->f_flags & O_DIRECT)

			ret = striped_read(inode, off, len,

					   pages, num_pages, checkeof,

					   1, (unsigned long)data & ~PAGE_MASK);

			ceph_put_page_vector(pages, num_pages, true);

	else



			if (ret <= 0)

				break;

			off += ret;

			iov_iter_advance(i, ret);

			if (ret < len)

				break;

		}

	} else {

		num_pages = calc_pages_for(off, len);

		pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);

		if (IS_ERR(pages))

			return PTR_ERR(pages);

		ret = striped_read(inode, off, len, pages,

					num_pages, checkeof, 0, 0);

		if (ret > 0) {

			int l, k = 0;

			size_t left = len = ret;



			while (left) {

				void __user *data = i->iov[0].iov_base

							+ i->iov_offset;

				l = min(i->iov[0].iov_len - i->iov_offset,

					left);



				ret = ceph_copy_page_vector_to_user(&pages[k],

								    data, off,

								    l);

				if (ret > 0) {

					iov_iter_advance(i, ret);

					left -= ret;

					off += ret;

					k = calc_pages_for(iocb->ki_pos,

							   len - left + 1) - 1;

					BUG_ON(k >= num_pages && left);

				} else

					break;

			}

		}

		ceph_release_page_vector(pages, num_pages);

	}



	if (off > iocb->ki_pos) {

		ret = off - iocb->ki_pos;

		iocb->ki_pos = off;

	}



	dout("sync_read result %d\n", ret);

	return ret;

}
@@ -758,55 +799,84 @@ static ssize_t ceph_aio_read(struct kiocb *iocb, const struct iovec *iov, 
{

	struct file *filp = iocb->ki_filp;

	struct ceph_file_info *fi = filp->private_data;

	loff_t *ppos = &iocb->ki_pos;

	size_t len = iov->iov_len;

	size_t len = iocb->ki_nbytes;

	struct inode *inode = file_inode(filp);

	struct ceph_inode_info *ci = ceph_inode(inode);

	void __user *base = iov->iov_base;

	ssize_t ret;

	int want, got = 0;

	int checkeof = 0, read = 0;



	dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",

	     inode, ceph_vinop(inode), pos, (unsigned)len, inode);

again:

	dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",

	     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len, inode);



	if (fi->fmode & CEPH_FILE_MODE_LAZY)

		want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;

	else

		want = CEPH_CAP_FILE_CACHE;

	ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want, &got, -1);

	if (ret < 0)

		return ret;



	if ((got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0 ||

	    (iocb->ki_filp->f_flags & O_DIRECT) ||

	    (fi->flags & CEPH_F_SYNC)) {

		struct iov_iter i;



		dout("aio_sync_read %p %llx.%llx %llu~%u got cap refs on %s\n",

		     inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,

		     ceph_cap_string(got));



		if (!read) {

			ret = generic_segment_checks(iov, &nr_segs,

							&len, VERIFY_WRITE);

			if (ret)

				goto out;

		}



		iov_iter_init(&i, iov, nr_segs, len, read);



		/* hmm, this isn't really async... */

		ret = ceph_sync_read(iocb, &i, &checkeof);

	} else {

		/*

		 * We can't modify the content of iov,

		 * so we only read from beginning.

		 */

		if (read) {

			iocb->ki_pos = pos;

			len = iocb->ki_nbytes;

			read = 0;

		}

		dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n",

		     inode, ceph_vinop(inode), pos, (unsigned)len,

		     ceph_cap_string(got));



	if ((got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0 ||

	    (iocb->ki_filp->f_flags & O_DIRECT) ||

	    (fi->flags & CEPH_F_SYNC))

		/* hmm, this isn't really async... */

		ret = ceph_sync_read(filp, base, len, ppos, &checkeof);

	else

		ret = generic_file_aio_read(iocb, iov, nr_segs, pos);



	}

out:

	dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n",

	     inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret);

	ceph_put_cap_refs(ci, got);



	if (checkeof && ret >= 0) {

		int statret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);

		int statret = ceph_do_getattr(inode,

					      CEPH_STAT_CAP_SIZE);



		/* hit EOF or hole? */

		if (statret == 0 && *ppos < inode->i_size) {

			dout("aio_read sync_read hit hole, ppos %lld < size %lld, reading more\n", *ppos, inode->i_size);

		if (statret == 0 && iocb->ki_pos < inode->i_size &&

			ret < len) {

			dout("sync_read hit hole, ppos %lld < size %lld"

			     ", reading more\n", iocb->ki_pos,

			     inode->i_size);



			read += ret;

			base += ret;

			len -= ret;

			checkeof = 0;

			goto again;

		}

	}



	if (ret >= 0)

		ret += read;