On 09/03/2013 04:52 PM, majianpeng wrote:
> For readv/preadv sync-operatoin, ceph only do the first iov.
> It don't think other iovs.Now implement this.
>
> Signed-off-by: Jianpeng Ma <majianpeng@xxxxxxxxx>
> ---
> fs/ceph/file.c | 175 ++++++++++++++++++++++++++++++++++++++++-----------------
> 1 file changed, 123 insertions(+), 52 deletions(-)
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index 3de8982..7d6a3ee 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -408,51 +408,95 @@ more:
> *
> * 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 iovec *iov,
> + unsigned long nr_segs, int *checkeof)
> {
> + struct file *file = iocb->ki_filp;
> struct inode *inode = file_inode(file);
> struct page **pages;
> - u64 off = *poff;
> - int num_pages, ret;
> + u64 off = iocb->ki_pos;
> + int num_pages, ret, i;
>
> - 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)iocb->ki_left,
> (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 + iocb->ki_left);
> if (ret < 0)
> - goto done;
> -
> - ret = striped_read(inode, off, len, pages, num_pages, checkeof,
> - file->f_flags & O_DIRECT,
> - (unsigned long)data & ~PAGE_MASK);
> + return ret;
>
> - 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;
> + if (file->f_flags & O_DIRECT) {
> + for (i = 0; i < nr_segs; i++) {
> + void __user *data = iov[i].iov_base;
> + size_t len = iov[i].iov_len;
> +
> + 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);
> +
> + ret = striped_read(inode, off, len,
> + pages, num_pages, checkeof,
> + 1, (unsigned long)data & ~PAGE_MASK);
> + ceph_put_page_vector(pages, num_pages, true);
> +
> + if (ret <= 0)
> + break;
> + off += ret;
> + if (ret < len)
> + break;
> + }
> + if (off > iocb->ki_pos) {
> + ret = off - iocb->ki_pos;
> + iocb->ki_pos = off;
> + iocb->ki_left -= ret;
> + }
> + } else {
> + size_t len = iocb->ki_left;
>
> -done:
> - if (file->f_flags & O_DIRECT)
> - ceph_put_page_vector(pages, 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);
> + ret = striped_read(inode, off, len, pages,
> + num_pages, checkeof, 0, 0);
> + len = ret;
> + if (len) {
> + int i, l, k = 0;
> + size_t left = len;
> +
> + for (i = 0; i < nr_segs && left; i++) {
> + void __user *data = iov[i].iov_base;
> + l = min(left, iov[i].iov_len);
> + ret = ceph_copy_page_vector_to_user(&pages[k],
> + data, off,
> + l);
> + if (ret > 0) {
> + left -= ret;
> + off += ret;
> + k = calc_pages_for(iocb->ki_pos,
> + len - left + 1) - 1;
> + BUG_ON(k >= num_pages && left);
> + } else
> + break;
> + }
> +
> + if (left == 0) {
> + iocb->ki_pos += len;
> + iocb->ki_left -= len;
> + ret = len;
> + }
If user program provides invalid buffer to readv syscall. 'left' can be larger than 0.
For this case, we should return size of data that were successfully copied
> + }
> ceph_release_page_vector(pages, num_pages);
> + }
> +
> dout("sync_read result %d\n", ret);
> return ret;
> }
> @@ -647,55 +691,82 @@ 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_left;
> 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:
> +
> 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)
> - goto out;
> + return ret;
> +
> 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))
> + (fi->flags & CEPH_F_SYNC)) {
> + unsigned long curr_seg = 0;
> + struct iovec *iov_clone;
> +
> + iov_clone = kmalloc(nr_segs * sizeof(struct iovec), GFP_KERNEL);
> + if (iov_clone == NULL) {
> + ret = -ENOMEM;
> + goto out;
> + }
> + memcpy(iov_clone, iov, nr_segs * sizeof(struct iovec));
why do we need to clone the iov ?
Regards
Yan, Zheng
> +again:
> /* 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);
> + ret = ceph_sync_read(iocb, &iov_clone[curr_seg],
> + nr_segs - curr_seg, &checkeof);
> +
> + if (checkeof && ret >= 0) {
> + int statret = ceph_do_getattr(inode,
> + CEPH_STAT_CAP_SIZE);
> +
> + /* hit EOF or hole? */
> + if (statret == 0 && iocb->ki_pos < inode->i_size &&
> + iocb->ki_left) {
> + size_t tmp = 0;
> + dout("%s sync_read hit hole, ppos %lld < size %lld"
> + ", reading more\n", __func__, iocb->ki_pos,
> + inode->i_size);
> +
> + read += ret;
> + for (; curr_seg < nr_segs; curr_seg++) {
> + if ((tmp + iov_clone[curr_seg].iov_len)
> + > ret)
> + break;
> + tmp += iov_clone[curr_seg].iov_len;
> + }
> +
> + BUG_ON(curr_seg == nr_segs);
> + iov_clone[curr_seg].iov_base += ret - tmp;
> + iov_clone[curr_seg].iov_len -= ret - tmp;
> + checkeof = 0;
> + goto again;
> + }
> + }
> + kfree(iov_clone);
>
> + } 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);
> -
> - /* 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);
> - read += ret;
> - base += ret;
> - len -= ret;
> - checkeof = 0;
> - goto again;
> - }
> - }
> if (ret >= 0)
> ret += read;
>
>
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