For readv/preadv sync-operatoin, ceph only do the first iov. It don't think other iovs.Now implement this.
V2: -add generic_segment_checks -using struct iov_iter replace cloning the iovs. -return previous successfully copied if ceph_copy_page_vector_to_user met error. Signed-off-by: Jianpeng Ma <majianp...@gmail.com> --- fs/ceph/file.c | 174 ++++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 123 insertions(+), 51 deletions(-) diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 3de8982..1c28c52 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -408,51 +408,109 @@ 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; - int num_pages, ret; + u64 off = iocb->ki_pos; + int num_pages, ret, n; - 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; + 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) { + for (n = 0; n < i->nr_segs; n++) { + void __user *data = i->iov[n].iov_base; + size_t len = i->iov[n].iov_len; + + if (n == 0) { + len -= i->iov_offset; + data += 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; + if (ret < len) + break; + } - 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 (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 l, k = 0; + size_t left = len; + + for (n = 0; n < i->nr_segs && left; n++) { + void __user *data = i->iov[n].iov_base; + l = min(left, i->iov[n].iov_len); + + if (n == 0) { + data += 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) { + left -= ret; + off += ret; + k = calc_pages_for(iocb->ki_pos, + len - left + 1) - 1; + BUG_ON(k >= num_pages && left); + } else + break; + } + + len -= left; + if (len > 0) { + iocb->ki_pos += len; + iocb->ki_left -= len; + ret = len; + } + } ceph_release_page_vector(pages, num_pages); + } + dout("sync_read result %d\n", ret); return ret; } @@ -647,55 +705,69 @@ 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; 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: + + ret = generic_segment_checks(iov, &nr_segs, &len, VERIFY_WRITE); + if (ret) + return ret; + 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)) { + struct iov_iter i; + + iocb->ki_left = len; + iov_iter_init(&i, iov, nr_segs, len, 0); +again: /* hmm, this isn't really async... */ - ret = ceph_sync_read(filp, base, len, ppos, &checkeof); - else + ret = ceph_sync_read(iocb, &i, &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) { + dout("sync_read hit hole, ppos %lld < size %lld" + ", reading more\n", iocb->ki_pos, + inode->i_size); + + read += ret; + iov_iter_advance(&i, ret); + checkeof = 0; + goto again; + } + } + + } 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; -- 1.8.1.2