On 09/24/2013 04:54 PM, majianpeng wrote: >> On 09/24/2013 04:05 PM, majianpeng wrote: >>> diff --git a/fs/ceph/file.c b/fs/ceph/file.c >>> index 3de8982..5422d8e 100644 >>> --- a/fs/ceph/file.c >>> +++ b/fs/ceph/file.c >>> @@ -408,51 +408,94 @@ 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 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; >>> >>> - 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) { >>> + 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; >>> + >>> + 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; >>> + iov_iter_advance(i, ret); >>> + if (ret < len) >>> + break; >>> + } >>> + } 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); >>> + 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; >>> + iocb->ki_left -= ret; >>> + } >>> + >>> dout("sync_read result %d\n", ret); >>> return ret; >>> } >>> @@ -647,17 +690,16 @@ 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 = 0; >> >> len = iocb->ki_left; > Yes, the dout need this. > >> >>> 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; >>> >> >> I think we should put label 'again' here. > Ok > >> >>> 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; >>> @@ -665,38 +707,61 @@ again: >>> 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)) { >>> + struct iov_iter i; >>> + >>> + if (!read) { >>> + ret = generic_segment_checks(iov, &nr_segs, >>> + &len, VERIFY_WRITE); >>> + if (ret) >>> + goto out; >>> + } >>> + >>> + iocb->ki_left = len; >> >> iocb->ki_left = len - read ? > Before goto again, i let 'len -= ret'. > len mean the left size. >> >> >>> + iov_iter_init(&i, iov, nr_segs, len, read); >>> /* hmm, this isn't really async... */ >>> - ret = ceph_sync_read(filp, base, len, ppos, &checkeof); >>> - else >>> + 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; >> >> forget to set 'read' to 0 ? > When define read, i set read = 0. > >int checkeof = 0, read = 0; I mean you need to reset 'read' to 0 here, because 'read' is used for calculating the return value. --- if (read) { iocb->ki_pos = pos; read = 0; } >> >> >>> 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 && >>> + iocb->ki_left) { >>> + 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) >>> + >>> + if (ret > 0) >>> ret += read; >> >> what is the purpose of this change ? > Sorry, i make a mistake. > >> >> Regards >> Yan, Zheng >>> >>> return ret; >>> -- >> > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html