diff options
Diffstat (limited to 'fs/splice.c')
-rw-r--r-- | fs/splice.c | 166 |
1 files changed, 83 insertions, 83 deletions
diff --git a/fs/splice.c b/fs/splice.c index a46ddd28561..b150493b6fc 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -78,7 +78,7 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *info, return 1; } - buf->flags |= PIPE_BUF_FLAG_STOLEN | PIPE_BUF_FLAG_LRU; + buf->flags |= PIPE_BUF_FLAG_LRU; return 0; } @@ -87,12 +87,11 @@ static void page_cache_pipe_buf_release(struct pipe_inode_info *info, { page_cache_release(buf->page); buf->page = NULL; - buf->flags &= ~(PIPE_BUF_FLAG_STOLEN | PIPE_BUF_FLAG_LRU); + buf->flags &= ~PIPE_BUF_FLAG_LRU; } -static void *page_cache_pipe_buf_map(struct file *file, - struct pipe_inode_info *info, - struct pipe_buffer *buf) +static int page_cache_pipe_buf_pin(struct pipe_inode_info *info, + struct pipe_buffer *buf) { struct page *page = buf->page; int err; @@ -118,64 +117,44 @@ static void *page_cache_pipe_buf_map(struct file *file, } /* - * Page is ok afterall, fall through to mapping. + * Page is ok afterall, we are done. */ unlock_page(page); } - return kmap(page); + return 0; error: unlock_page(page); - return ERR_PTR(err); -} - -static void page_cache_pipe_buf_unmap(struct pipe_inode_info *info, - struct pipe_buffer *buf) -{ - kunmap(buf->page); -} - -static void *user_page_pipe_buf_map(struct file *file, - struct pipe_inode_info *pipe, - struct pipe_buffer *buf) -{ - return kmap(buf->page); -} - -static void user_page_pipe_buf_unmap(struct pipe_inode_info *pipe, - struct pipe_buffer *buf) -{ - kunmap(buf->page); -} - -static void page_cache_pipe_buf_get(struct pipe_inode_info *info, - struct pipe_buffer *buf) -{ - page_cache_get(buf->page); + return err; } static struct pipe_buf_operations page_cache_pipe_buf_ops = { .can_merge = 0, - .map = page_cache_pipe_buf_map, - .unmap = page_cache_pipe_buf_unmap, + .map = generic_pipe_buf_map, + .unmap = generic_pipe_buf_unmap, + .pin = page_cache_pipe_buf_pin, .release = page_cache_pipe_buf_release, .steal = page_cache_pipe_buf_steal, - .get = page_cache_pipe_buf_get, + .get = generic_pipe_buf_get, }; static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { - return 1; + if (!(buf->flags & PIPE_BUF_FLAG_GIFT)) + return 1; + + return 0; } static struct pipe_buf_operations user_page_pipe_buf_ops = { .can_merge = 0, - .map = user_page_pipe_buf_map, - .unmap = user_page_pipe_buf_unmap, + .map = generic_pipe_buf_map, + .unmap = generic_pipe_buf_unmap, + .pin = generic_pipe_buf_pin, .release = page_cache_pipe_buf_release, .steal = user_page_pipe_buf_steal, - .get = page_cache_pipe_buf_get, + .get = generic_pipe_buf_get, }; /* @@ -210,6 +189,9 @@ static ssize_t splice_to_pipe(struct pipe_inode_info *pipe, buf->offset = spd->partial[page_nr].offset; buf->len = spd->partial[page_nr].len; buf->ops = spd->ops; + if (spd->flags & SPLICE_F_GIFT) + buf->flags |= PIPE_BUF_FLAG_GIFT; + pipe->nrbufs++; page_nr++; ret += buf->len; @@ -326,6 +308,12 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, page = find_get_page(mapping, index); if (!page) { /* + * Make sure the read-ahead engine is notified + * about this failure. + */ + handle_ra_miss(mapping, &in->f_ra, index); + + /* * page didn't exist, allocate one. */ page = page_cache_alloc_cold(mapping); @@ -517,26 +505,16 @@ static int pipe_to_sendpage(struct pipe_inode_info *info, { struct file *file = sd->file; loff_t pos = sd->pos; - ssize_t ret; - void *ptr; - int more; - - /* - * Sub-optimal, but we are limited by the pipe ->map. We don't - * need a kmap'ed buffer here, we just want to make sure we - * have the page pinned if the pipe page originates from the - * page cache. - */ - ptr = buf->ops->map(file, info, buf); - if (IS_ERR(ptr)) - return PTR_ERR(ptr); + int ret, more; - more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len; + ret = buf->ops->pin(info, buf); + if (!ret) { + more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len; - ret = file->f_op->sendpage(file, buf->page, buf->offset, sd->len, - &pos, more); + ret = file->f_op->sendpage(file, buf->page, buf->offset, + sd->len, &pos, more); + } - buf->ops->unmap(info, buf); return ret; } @@ -569,15 +547,14 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf, unsigned int offset, this_len; struct page *page; pgoff_t index; - char *src; int ret; /* * make sure the data in this buffer is uptodate */ - src = buf->ops->map(file, info, buf); - if (IS_ERR(src)) - return PTR_ERR(src); + ret = buf->ops->pin(info, buf); + if (unlikely(ret)) + return ret; index = sd->pos >> PAGE_CACHE_SHIFT; offset = sd->pos & ~PAGE_CACHE_MASK; @@ -587,9 +564,10 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf, this_len = PAGE_CACHE_SIZE - offset; /* - * Reuse buf page, if SPLICE_F_MOVE is set. + * Reuse buf page, if SPLICE_F_MOVE is set and we are doing a full + * page. */ - if (sd->flags & SPLICE_F_MOVE) { + if ((sd->flags & SPLICE_F_MOVE) && this_len == PAGE_CACHE_SIZE) { /* * If steal succeeds, buf->page is now pruned from the vm * side (LRU and page cache) and we can reuse it. The page @@ -599,8 +577,12 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf, goto find_page; page = buf->page; - if (add_to_page_cache(page, mapping, index, gfp_mask)) + if (add_to_page_cache(page, mapping, index, gfp_mask)) { + unlock_page(page); goto find_page; + } + + page_cache_get(page); if (!(buf->flags & PIPE_BUF_FLAG_LRU)) lru_cache_add(page); @@ -660,34 +642,36 @@ find_page: } else if (ret) goto out; - if (!(buf->flags & PIPE_BUF_FLAG_STOLEN)) { - char *dst = kmap_atomic(page, KM_USER0); + if (buf->page != page) { + /* + * Careful, ->map() uses KM_USER0! + */ + char *src = buf->ops->map(info, buf, 1); + char *dst = kmap_atomic(page, KM_USER1); memcpy(dst + offset, src + buf->offset, this_len); flush_dcache_page(page); - kunmap_atomic(dst, KM_USER0); + kunmap_atomic(dst, KM_USER1); + buf->ops->unmap(info, buf, src); } ret = mapping->a_ops->commit_write(file, page, offset, offset+this_len); - if (ret == AOP_TRUNCATED_PAGE) { + if (!ret) { + /* + * Return the number of bytes written and mark page as + * accessed, we are now done! + */ + ret = this_len; + mark_page_accessed(page); + balance_dirty_pages_ratelimited(mapping); + } else if (ret == AOP_TRUNCATED_PAGE) { page_cache_release(page); goto find_page; - } else if (ret) - goto out; - - /* - * Return the number of bytes written. - */ - ret = this_len; - mark_page_accessed(page); - balance_dirty_pages_ratelimited(mapping); + } out: - if (!(buf->flags & PIPE_BUF_FLAG_STOLEN)) - page_cache_release(page); - + page_cache_release(page); unlock_page(page); out_nomem: - buf->ops->unmap(info, buf); return ret; } @@ -1095,7 +1079,7 @@ static long do_splice(struct file *in, loff_t __user *off_in, */ static int get_iovec_page_array(const struct iovec __user *iov, unsigned int nr_vecs, struct page **pages, - struct partial_page *partial) + struct partial_page *partial, int aligned) { int buffers = 0, error = 0; @@ -1135,6 +1119,15 @@ static int get_iovec_page_array(const struct iovec __user *iov, * in the user pages. */ off = (unsigned long) base & ~PAGE_MASK; + + /* + * If asked for alignment, the offset must be zero and the + * length a multiple of the PAGE_SIZE. + */ + error = -EINVAL; + if (aligned && (off || len & ~PAGE_MASK)) + break; + npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT; if (npages > PIPE_BUFFERS - buffers) npages = PIPE_BUFFERS - buffers; @@ -1228,7 +1221,8 @@ static long do_vmsplice(struct file *file, const struct iovec __user *iov, else if (unlikely(!nr_segs)) return 0; - spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial); + spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial, + flags & SPLICE_F_GIFT); if (spd.nr_pages <= 0) return spd.nr_pages; @@ -1336,6 +1330,12 @@ static int link_pipe(struct pipe_inode_info *ipipe, obuf = opipe->bufs + nbuf; *obuf = *ibuf; + /* + * Don't inherit the gift flag, we need to + * prevent multiple steals of this page. + */ + obuf->flags &= ~PIPE_BUF_FLAG_GIFT; + if (obuf->len > len) obuf->len = len; |