Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
[pandora-kernel.git] / fs / splice.c
index 9313b61..ac22b00 100644 (file)
@@ -193,8 +193,8 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
                        break;
                }
 
-               if (pipe->nrbufs < PIPE_BUFFERS) {
-                       int newbuf = (pipe->curbuf + pipe->nrbufs) & (PIPE_BUFFERS - 1);
+               if (pipe->nrbufs < pipe->buffers) {
+                       int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
                        struct pipe_buffer *buf = pipe->bufs + newbuf;
 
                        buf->page = spd->pages[page_nr];
@@ -214,7 +214,7 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
 
                        if (!--spd->nr_pages)
                                break;
-                       if (pipe->nrbufs < PIPE_BUFFERS)
+                       if (pipe->nrbufs < pipe->buffers)
                                continue;
 
                        break;
@@ -265,6 +265,36 @@ static void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
        page_cache_release(spd->pages[i]);
 }
 
+/*
+ * Check if we need to grow the arrays holding pages and partial page
+ * descriptions.
+ */
+int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
+{
+       if (pipe->buffers <= PIPE_DEF_BUFFERS)
+               return 0;
+
+       spd->pages = kmalloc(pipe->buffers * sizeof(struct page *), GFP_KERNEL);
+       spd->partial = kmalloc(pipe->buffers * sizeof(struct partial_page), GFP_KERNEL);
+
+       if (spd->pages && spd->partial)
+               return 0;
+
+       kfree(spd->pages);
+       kfree(spd->partial);
+       return -ENOMEM;
+}
+
+void splice_shrink_spd(struct pipe_inode_info *pipe,
+                      struct splice_pipe_desc *spd)
+{
+       if (pipe->buffers <= PIPE_DEF_BUFFERS)
+               return;
+
+       kfree(spd->pages);
+       kfree(spd->partial);
+}
+
 static int
 __generic_file_splice_read(struct file *in, loff_t *ppos,
                           struct pipe_inode_info *pipe, size_t len,
@@ -272,8 +302,8 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 {
        struct address_space *mapping = in->f_mapping;
        unsigned int loff, nr_pages, req_pages;
-       struct page *pages[PIPE_BUFFERS];
-       struct partial_page partial[PIPE_BUFFERS];
+       struct page *pages[PIPE_DEF_BUFFERS];
+       struct partial_page partial[PIPE_DEF_BUFFERS];
        struct page *page;
        pgoff_t index, end_index;
        loff_t isize;
@@ -286,15 +316,18 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
                .spd_release = spd_release_page,
        };
 
+       if (splice_grow_spd(pipe, &spd))
+               return -ENOMEM;
+
        index = *ppos >> PAGE_CACHE_SHIFT;
        loff = *ppos & ~PAGE_CACHE_MASK;
        req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-       nr_pages = min(req_pages, (unsigned)PIPE_BUFFERS);
+       nr_pages = min(req_pages, pipe->buffers);
 
        /*
         * Lookup the (hopefully) full range of pages we need.
         */
-       spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, pages);
+       spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, spd.pages);
        index += spd.nr_pages;
 
        /*
@@ -335,7 +368,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
                        unlock_page(page);
                }
 
-               pages[spd.nr_pages++] = page;
+               spd.pages[spd.nr_pages++] = page;
                index++;
        }
 
@@ -356,7 +389,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
                 * this_len is the max we'll use from this page
                 */
                this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff);
-               page = pages[page_nr];
+               page = spd.pages[page_nr];
 
                if (PageReadahead(page))
                        page_cache_async_readahead(mapping, &in->f_ra, in,
@@ -393,8 +426,8 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
                                        error = -ENOMEM;
                                        break;
                                }
-                               page_cache_release(pages[page_nr]);
-                               pages[page_nr] = page;
+                               page_cache_release(spd.pages[page_nr]);
+                               spd.pages[page_nr] = page;
                        }
                        /*
                         * page was already under io and is now done, great
@@ -451,8 +484,8 @@ fill_it:
                        len = this_len;
                }
 
-               partial[page_nr].offset = loff;
-               partial[page_nr].len = this_len;
+               spd.partial[page_nr].offset = loff;
+               spd.partial[page_nr].len = this_len;
                len -= this_len;
                loff = 0;
                spd.nr_pages++;
@@ -464,12 +497,13 @@ fill_it:
         * we got, 'nr_pages' is how many pages are in the map.
         */
        while (page_nr < nr_pages)
-               page_cache_release(pages[page_nr++]);
+               page_cache_release(spd.pages[page_nr++]);
        in->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
 
        if (spd.nr_pages)
-               return splice_to_pipe(pipe, &spd);
+               error = splice_to_pipe(pipe, &spd);
 
+       splice_shrink_spd(pipe, &spd);
        return error;
 }
 
@@ -560,9 +594,9 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
        unsigned int nr_pages;
        unsigned int nr_freed;
        size_t offset;
-       struct page *pages[PIPE_BUFFERS];
-       struct partial_page partial[PIPE_BUFFERS];
-       struct iovec vec[PIPE_BUFFERS];
+       struct page *pages[PIPE_DEF_BUFFERS];
+       struct partial_page partial[PIPE_DEF_BUFFERS];
+       struct iovec *vec, __vec[PIPE_DEF_BUFFERS];
        pgoff_t index;
        ssize_t res;
        size_t this_len;
@@ -576,11 +610,22 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
                .spd_release = spd_release_page,
        };
 
+       if (splice_grow_spd(pipe, &spd))
+               return -ENOMEM;
+
+       res = -ENOMEM;
+       vec = __vec;
+       if (pipe->buffers > PIPE_DEF_BUFFERS) {
+               vec = kmalloc(pipe->buffers * sizeof(struct iovec), GFP_KERNEL);
+               if (!vec)
+                       goto shrink_ret;
+       }
+
        index = *ppos >> PAGE_CACHE_SHIFT;
        offset = *ppos & ~PAGE_CACHE_MASK;
        nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 
-       for (i = 0; i < nr_pages && i < PIPE_BUFFERS && len; i++) {
+       for (i = 0; i < nr_pages && i < pipe->buffers && len; i++) {
                struct page *page;
 
                page = alloc_page(GFP_USER);
@@ -591,7 +636,7 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
                this_len = min_t(size_t, len, PAGE_CACHE_SIZE - offset);
                vec[i].iov_base = (void __user *) page_address(page);
                vec[i].iov_len = this_len;
-               pages[i] = page;
+               spd.pages[i] = page;
                spd.nr_pages++;
                len -= this_len;
                offset = 0;
@@ -610,11 +655,11 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
        nr_freed = 0;
        for (i = 0; i < spd.nr_pages; i++) {
                this_len = min_t(size_t, vec[i].iov_len, res);
-               partial[i].offset = 0;
-               partial[i].len = this_len;
+               spd.partial[i].offset = 0;
+               spd.partial[i].len = this_len;
                if (!this_len) {
-                       __free_page(pages[i]);
-                       pages[i] = NULL;
+                       __free_page(spd.pages[i]);
+                       spd.pages[i] = NULL;
                        nr_freed++;
                }
                res -= this_len;
@@ -625,13 +670,18 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
        if (res > 0)
                *ppos += res;
 
+shrink_ret:
+       if (vec != __vec)
+               kfree(vec);
+       splice_shrink_spd(pipe, &spd);
        return res;
 
 err:
        for (i = 0; i < spd.nr_pages; i++)
-               __free_page(pages[i]);
+               __free_page(spd.pages[i]);
 
-       return error;
+       res = error;
+       goto shrink_ret;
 }
 EXPORT_SYMBOL(default_file_splice_read);
 
@@ -784,7 +834,7 @@ int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd,
                if (!buf->len) {
                        buf->ops = NULL;
                        ops->release(pipe, buf);
-                       pipe->curbuf = (pipe->curbuf + 1) & (PIPE_BUFFERS - 1);
+                       pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
                        pipe->nrbufs--;
                        if (pipe->inode)
                                sd->need_wakeup = true;
@@ -1211,7 +1261,7 @@ out_release:
         * If we did an incomplete transfer we must release
         * the pipe buffers in question:
         */
-       for (i = 0; i < PIPE_BUFFERS; i++) {
+       for (i = 0; i < pipe->buffers; i++) {
                struct pipe_buffer *buf = pipe->bufs + i;
 
                if (buf->ops) {
@@ -1371,7 +1421,8 @@ 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, int aligned)
+                               struct partial_page *partial, int aligned,
+                               unsigned int pipe_buffers)
 {
        int buffers = 0, error = 0;
 
@@ -1414,8 +1465,8 @@ static int get_iovec_page_array(const struct iovec __user *iov,
                        break;
 
                npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-               if (npages > PIPE_BUFFERS - buffers)
-                       npages = PIPE_BUFFERS - buffers;
+               if (npages > pipe_buffers - buffers)
+                       npages = pipe_buffers - buffers;
 
                error = get_user_pages_fast((unsigned long)base, npages,
                                        0, &pages[buffers]);
@@ -1450,7 +1501,7 @@ static int get_iovec_page_array(const struct iovec __user *iov,
                 * or if we mapped the max number of pages that we have
                 * room for.
                 */
-               if (error < npages || buffers == PIPE_BUFFERS)
+               if (error < npages || buffers == pipe_buffers)
                        break;
 
                nr_vecs--;
@@ -1593,8 +1644,8 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
                             unsigned long nr_segs, unsigned int flags)
 {
        struct pipe_inode_info *pipe;
-       struct page *pages[PIPE_BUFFERS];
-       struct partial_page partial[PIPE_BUFFERS];
+       struct page *pages[PIPE_DEF_BUFFERS];
+       struct partial_page partial[PIPE_DEF_BUFFERS];
        struct splice_pipe_desc spd = {
                .pages = pages,
                .partial = partial,
@@ -1602,17 +1653,25 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
                .ops = &user_page_pipe_buf_ops,
                .spd_release = spd_release_page,
        };
+       long ret;
 
        pipe = pipe_info(file->f_path.dentry->d_inode);
        if (!pipe)
                return -EBADF;
 
-       spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial,
-                                           flags & SPLICE_F_GIFT);
+       if (splice_grow_spd(pipe, &spd))
+               return -ENOMEM;
+
+       spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages,
+                                           spd.partial, flags & SPLICE_F_GIFT,
+                                           pipe->buffers);
        if (spd.nr_pages <= 0)
-               return spd.nr_pages;
+               ret = spd.nr_pages;
+       else
+               ret = splice_to_pipe(pipe, &spd);
 
-       return splice_to_pipe(pipe, &spd);
+       splice_shrink_spd(pipe, &spd);
+       return ret;
 }
 
 /*
@@ -1738,13 +1797,13 @@ static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
         * Check ->nrbufs without the inode lock first. This function
         * is speculative anyways, so missing one is ok.
         */
-       if (pipe->nrbufs < PIPE_BUFFERS)
+       if (pipe->nrbufs < pipe->buffers)
                return 0;
 
        ret = 0;
        pipe_lock(pipe);
 
-       while (pipe->nrbufs >= PIPE_BUFFERS) {
+       while (pipe->nrbufs >= pipe->buffers) {
                if (!pipe->readers) {
                        send_sig(SIGPIPE, current, 0);
                        ret = -EPIPE;
@@ -1810,7 +1869,7 @@ retry:
                 * Cannot make any progress, because either the input
                 * pipe is empty or the output pipe is full.
                 */
-               if (!ipipe->nrbufs || opipe->nrbufs >= PIPE_BUFFERS) {
+               if (!ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) {
                        /* Already processed some buffers, break */
                        if (ret)
                                break;
@@ -1831,7 +1890,7 @@ retry:
                }
 
                ibuf = ipipe->bufs + ipipe->curbuf;
-               nbuf = (opipe->curbuf + opipe->nrbufs) % PIPE_BUFFERS;
+               nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
                obuf = opipe->bufs + nbuf;
 
                if (len >= ibuf->len) {
@@ -1841,7 +1900,7 @@ retry:
                        *obuf = *ibuf;
                        ibuf->ops = NULL;
                        opipe->nrbufs++;
-                       ipipe->curbuf = (ipipe->curbuf + 1) % PIPE_BUFFERS;
+                       ipipe->curbuf = (ipipe->curbuf + 1) & (ipipe->buffers - 1);
                        ipipe->nrbufs--;
                        input_wakeup = true;
                } else {
@@ -1914,11 +1973,11 @@ static int link_pipe(struct pipe_inode_info *ipipe,
                 * If we have iterated all input buffers or ran out of
                 * output room, break.
                 */
-               if (i >= ipipe->nrbufs || opipe->nrbufs >= PIPE_BUFFERS)
+               if (i >= ipipe->nrbufs || opipe->nrbufs >= opipe->buffers)
                        break;
 
-               ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (PIPE_BUFFERS - 1));
-               nbuf = (opipe->curbuf + opipe->nrbufs) & (PIPE_BUFFERS - 1);
+               ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (ipipe->buffers-1));
+               nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
 
                /*
                 * Get a reference to this pipe buffer,