Message ID | 201309241605181783589@gmail.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
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; > 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. > 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 ? > + 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 ? > 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 ? Regards Yan, Zheng > > return ret; > -- -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
>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; > > >> 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; >> -- >
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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
>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. > Yes, i see. by the way, dout used pos and len so i think we should put dout in different place. > >--- >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; >>>> -- >>> >> >
>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; Because commit 73a7075e3f6ec63dc359064e, remove the "iocb->ki_left = len" in func do_sync_read. So using iocb->ki_nbytes. Thanks! Jianpeng Ma
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; 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; @@ -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; + 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; 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; return ret;
For readv/preadv sync-operatoin, ceph only do the first iov. It don't think other iovs.Now implement this. V5: -before getattr,it must put caps which already holded avoid deadlock. -only do generic_segment_checks for sync-read avoid do again in func generic_file_aio_read V4: -modify one bug. V3: -modify some bug. 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 <majianpeng@gmail.com> --- fs/ceph/file.c | 149 +++++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 107 insertions(+), 42 deletions(-) -- 1.8.4-rc0