From 05afcb77eb4713f46e7ebaa3cb54bc465c5d516e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 23 Jan 2015 01:08:07 -0500 Subject: [PATCH 1/2] new helper: iov_iter_bvec() similar to iov_iter_kvec(), for ITER_BVEC ones Signed-off-by: Al Viro --- fs/splice.c | 7 ++----- include/linux/uio.h | 4 +++- mm/iov_iter.c | 17 +++++++++++++++-- mm/page_io.c | 9 ++------- 4 files changed, 22 insertions(+), 15 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index 75c6058eabf2..7c7176f2d1e7 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1006,11 +1006,8 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, } /* ... iov_iter */ - from.type = ITER_BVEC | WRITE; - from.bvec = array; - from.nr_segs = n; - from.count = sd.total_len - left; - from.iov_offset = 0; + iov_iter_bvec(&from, ITER_BVEC | WRITE, array, n, + sd.total_len - left); /* ... and iocb */ init_sync_kiocb(&kiocb, out); diff --git a/include/linux/uio.h b/include/linux/uio.h index 1c5e453f7ea9..b447402d9737 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -88,7 +88,9 @@ size_t iov_iter_zero(size_t bytes, struct iov_iter *); unsigned long iov_iter_alignment(const struct iov_iter *i); void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov, unsigned long nr_segs, size_t count); -void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *iov, +void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *kvec, + unsigned long nr_segs, size_t count); +void iov_iter_bvec(struct iov_iter *i, int direction, const struct bio_vec *bvec, unsigned long nr_segs, size_t count); ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, size_t *start); diff --git a/mm/iov_iter.c b/mm/iov_iter.c index a1599ca4ab0e..827732047da1 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -501,18 +501,31 @@ size_t iov_iter_single_seg_count(const struct iov_iter *i) EXPORT_SYMBOL(iov_iter_single_seg_count); void iov_iter_kvec(struct iov_iter *i, int direction, - const struct kvec *iov, unsigned long nr_segs, + const struct kvec *kvec, unsigned long nr_segs, size_t count) { BUG_ON(!(direction & ITER_KVEC)); i->type = direction; - i->kvec = (struct kvec *)iov; + i->kvec = kvec; i->nr_segs = nr_segs; i->iov_offset = 0; i->count = count; } EXPORT_SYMBOL(iov_iter_kvec); +void iov_iter_bvec(struct iov_iter *i, int direction, + const struct bio_vec *bvec, unsigned long nr_segs, + size_t count) +{ + BUG_ON(!(direction & ITER_BVEC)); + i->type = direction; + i->bvec = bvec; + i->nr_segs = nr_segs; + i->iov_offset = 0; + i->count = count; +} +EXPORT_SYMBOL(iov_iter_bvec); + unsigned long iov_iter_alignment(const struct iov_iter *i) { unsigned long res = 0; diff --git a/mm/page_io.c b/mm/page_io.c index 955db8b0d497..e6045804c8d8 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -269,14 +269,9 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc, .bv_len = PAGE_SIZE, .bv_offset = 0 }; - struct iov_iter from = { - .type = ITER_BVEC | WRITE, - .count = PAGE_SIZE, - .iov_offset = 0, - .nr_segs = 1, - }; - from.bvec = &bv; /* older gcc versions are broken */ + struct iov_iter from; + iov_iter_bvec(&from, ITER_BVEC | WRITE, &bv, 1, PAGE_SIZE); init_sync_kiocb(&kiocb, swap_file); kiocb.ki_pos = page_file_offset(page); kiocb.ki_nbytes = PAGE_SIZE; From dbe4e192a234cd6133d86fffb965d0f032c12ccc Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 25 Jan 2015 21:11:59 +0100 Subject: [PATCH 2/2] fs: add vfs_iter_{read,write} helpers Simple helpers that pass an arbitrary iov_iter to filesystems. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/read_write.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ fs/splice.c | 16 ++-------------- include/linux/fs.h | 3 +++ 3 files changed, 51 insertions(+), 14 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index c0805c93b6fa..ab4f26a7d5cb 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -333,6 +333,52 @@ out_putf: } #endif +ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos) +{ + struct kiocb kiocb; + ssize_t ret; + + if (!file->f_op->read_iter) + return -EINVAL; + + init_sync_kiocb(&kiocb, file); + kiocb.ki_pos = *ppos; + kiocb.ki_nbytes = iov_iter_count(iter); + + iter->type |= READ; + ret = file->f_op->read_iter(&kiocb, iter); + if (ret == -EIOCBQUEUED) + ret = wait_on_sync_kiocb(&kiocb); + + if (ret > 0) + *ppos = kiocb.ki_pos; + return ret; +} +EXPORT_SYMBOL(vfs_iter_read); + +ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos) +{ + struct kiocb kiocb; + ssize_t ret; + + if (!file->f_op->write_iter) + return -EINVAL; + + init_sync_kiocb(&kiocb, file); + kiocb.ki_pos = *ppos; + kiocb.ki_nbytes = iov_iter_count(iter); + + iter->type |= WRITE; + ret = file->f_op->write_iter(&kiocb, iter); + if (ret == -EIOCBQUEUED) + ret = wait_on_sync_kiocb(&kiocb); + + if (ret > 0) + *ppos = kiocb.ki_pos; + return ret; +} +EXPORT_SYMBOL(vfs_iter_write); + /* * rw_verify_area doesn't like huge counts. We limit * them to something that fits in "int" so that others diff --git a/fs/splice.c b/fs/splice.c index 7c7176f2d1e7..7968da96bebb 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -961,7 +961,6 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, splice_from_pipe_begin(&sd); while (sd.total_len) { struct iov_iter from; - struct kiocb kiocb; size_t left; int n, idx; @@ -1005,26 +1004,15 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, left -= this_len; } - /* ... iov_iter */ iov_iter_bvec(&from, ITER_BVEC | WRITE, array, n, sd.total_len - left); - - /* ... and iocb */ - init_sync_kiocb(&kiocb, out); - kiocb.ki_pos = sd.pos; - kiocb.ki_nbytes = sd.total_len - left; - - /* now, send it */ - ret = out->f_op->write_iter(&kiocb, &from); - if (-EIOCBQUEUED == ret) - ret = wait_on_sync_kiocb(&kiocb); - + ret = vfs_iter_write(out, &from, &sd.pos); if (ret <= 0) break; sd.num_spliced += ret; sd.total_len -= ret; - *ppos = sd.pos = kiocb.ki_pos; + *ppos = sd.pos; /* dismiss the fully eaten buffers, adjust the partial one */ while (ret) { diff --git a/include/linux/fs.h b/include/linux/fs.h index 42efe13077b6..1f3c43952540 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2494,6 +2494,9 @@ extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t l extern ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos); extern ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos); +ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos); +ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos); + /* fs/block_dev.c */ extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to); extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from);