From 8eb4efb091c8d8f70a0e6822288b043f8691ec51 Mon Sep 17 00:00:00 2001 From: majianpeng Date: Thu, 26 Sep 2013 14:42:17 +0800 Subject: [PATCH] ceph: implement readv/preadv for sync operation For readv/preadv sync-operatoin, ceph only do the first iov. Now implement this. Signed-off-by: Jianpeng Ma Reviewed-by: Yan, Zheng --- fs/ceph/file.c | 162 +++++++++++++++++++++++++++++++++++-------------- 1 file changed, 116 insertions(+), 46 deletions(-) diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 5cf034e915bb..c4419e848a4f 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -408,51 +408,92 @@ 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; + 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) - ceph_put_page_vector(pages, num_pages, true); - else + 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 { + 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) - goto out; - 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)); + 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)) - /* 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); + (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)); + + 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;