string: factorize skip_spaces and export it to be generally available
[safe/jmp/linux-2.6] / fs / splice.c
index e405cf5..3920866 100644 (file)
@@ -502,14 +502,138 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
                len = left;
 
        ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
-       if (ret > 0)
+       if (ret > 0) {
                *ppos += ret;
+               file_accessed(in);
+       }
 
        return ret;
 }
-
 EXPORT_SYMBOL(generic_file_splice_read);
 
+static const struct pipe_buf_operations default_pipe_buf_ops = {
+       .can_merge = 0,
+       .map = generic_pipe_buf_map,
+       .unmap = generic_pipe_buf_unmap,
+       .confirm = generic_pipe_buf_confirm,
+       .release = generic_pipe_buf_release,
+       .steal = generic_pipe_buf_steal,
+       .get = generic_pipe_buf_get,
+};
+
+static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
+                           unsigned long vlen, loff_t offset)
+{
+       mm_segment_t old_fs;
+       loff_t pos = offset;
+       ssize_t res;
+
+       old_fs = get_fs();
+       set_fs(get_ds());
+       /* The cast to a user pointer is valid due to the set_fs() */
+       res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos);
+       set_fs(old_fs);
+
+       return res;
+}
+
+static ssize_t kernel_write(struct file *file, const char *buf, size_t count,
+                           loff_t pos)
+{
+       mm_segment_t old_fs;
+       ssize_t res;
+
+       old_fs = get_fs();
+       set_fs(get_ds());
+       /* The cast to a user pointer is valid due to the set_fs() */
+       res = vfs_write(file, (const char __user *)buf, count, &pos);
+       set_fs(old_fs);
+
+       return res;
+}
+
+ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
+                                struct pipe_inode_info *pipe, size_t len,
+                                unsigned int flags)
+{
+       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];
+       pgoff_t index;
+       ssize_t res;
+       size_t this_len;
+       int error;
+       int i;
+       struct splice_pipe_desc spd = {
+               .pages = pages,
+               .partial = partial,
+               .flags = flags,
+               .ops = &default_pipe_buf_ops,
+               .spd_release = spd_release_page,
+       };
+
+       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++) {
+               struct page *page;
+
+               page = alloc_page(GFP_USER);
+               error = -ENOMEM;
+               if (!page)
+                       goto err;
+
+               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.nr_pages++;
+               len -= this_len;
+               offset = 0;
+       }
+
+       res = kernel_readv(in, vec, spd.nr_pages, *ppos);
+       if (res < 0) {
+               error = res;
+               goto err;
+       }
+
+       error = 0;
+       if (!res)
+               goto err;
+
+       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;
+               if (!this_len) {
+                       __free_page(pages[i]);
+                       pages[i] = NULL;
+                       nr_freed++;
+               }
+               res -= this_len;
+       }
+       spd.nr_pages -= nr_freed;
+
+       res = splice_to_pipe(pipe, &spd);
+       if (res > 0)
+               *ppos += res;
+
+       return res;
+
+err:
+       for (i = 0; i < spd.nr_pages; i++)
+               __free_page(pages[i]);
+
+       return error;
+}
+EXPORT_SYMBOL(default_file_splice_read);
+
 /*
  * Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos'
  * using sendpage(). Return the number of bytes sent.
@@ -524,9 +648,11 @@ static int pipe_to_sendpage(struct pipe_inode_info *pipe,
        ret = buf->ops->confirm(pipe, 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);
+               if (file->f_op && file->f_op->sendpage)
+                       ret = file->f_op->sendpage(file, buf->page, buf->offset,
+                                                  sd->len, &pos, more);
+               else
+                       ret = -EINVAL;
        }
 
        return ret;
@@ -841,8 +967,10 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
 
                mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
                ret = file_remove_suid(out);
-               if (!ret)
+               if (!ret) {
+                       file_update_time(out);
                        ret = splice_from_pipe_feed(pipe, &sd, pipe_to_file);
+               }
                mutex_unlock(&inode->i_mutex);
        } while (ret > 0);
        splice_from_pipe_end(pipe, &sd);
@@ -854,25 +982,15 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
 
        if (ret > 0) {
                unsigned long nr_pages;
+               int err;
 
-               *ppos += ret;
                nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 
-               /*
-                * If file or inode is SYNC and we actually wrote some data,
-                * sync it.
-                */
-               if (unlikely((out->f_flags & O_SYNC) || IS_SYNC(inode))) {
-                       int err;
-
-                       mutex_lock(&inode->i_mutex);
-                       err = generic_osync_inode(inode, mapping,
-                                                 OSYNC_METADATA|OSYNC_DATA);
-                       mutex_unlock(&inode->i_mutex);
-
-                       if (err)
-                               ret = err;
-               }
+               err = generic_write_sync(out, *ppos, ret);
+               if (err)
+                       ret = err;
+               else
+                       *ppos += ret;
                balance_dirty_pages_ratelimited_nr(mapping, nr_pages);
        }
 
@@ -881,6 +999,36 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
 
 EXPORT_SYMBOL(generic_file_splice_write);
 
+static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
+                         struct splice_desc *sd)
+{
+       int ret;
+       void *data;
+
+       ret = buf->ops->confirm(pipe, buf);
+       if (ret)
+               return ret;
+
+       data = buf->ops->map(pipe, buf, 0);
+       ret = kernel_write(sd->u.file, data + buf->offset, sd->len, sd->pos);
+       buf->ops->unmap(pipe, buf, data);
+
+       return ret;
+}
+
+static ssize_t default_file_splice_write(struct pipe_inode_info *pipe,
+                                        struct file *out, loff_t *ppos,
+                                        size_t len, unsigned int flags)
+{
+       ssize_t ret;
+
+       ret = splice_from_pipe(pipe, out, ppos, len, flags, write_pipe_buf);
+       if (ret > 0)
+               *ppos += ret;
+
+       return ret;
+}
+
 /**
  * generic_splice_sendpage - splice data from a pipe to a socket
  * @pipe:      pipe to splice from
@@ -908,11 +1056,10 @@ EXPORT_SYMBOL(generic_splice_sendpage);
 static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
                           loff_t *ppos, size_t len, unsigned int flags)
 {
+       ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
+                               loff_t *, size_t, unsigned int);
        int ret;
 
-       if (unlikely(!out->f_op || !out->f_op->splice_write))
-               return -EINVAL;
-
        if (unlikely(!(out->f_mode & FMODE_WRITE)))
                return -EBADF;
 
@@ -923,7 +1070,12 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
        if (unlikely(ret < 0))
                return ret;
 
-       return out->f_op->splice_write(pipe, out, ppos, len, flags);
+       if (out->f_op && out->f_op->splice_write)
+               splice_write = out->f_op->splice_write;
+       else
+               splice_write = default_file_splice_write;
+
+       return splice_write(pipe, out, ppos, len, flags);
 }
 
 /*
@@ -933,11 +1085,10 @@ static long do_splice_to(struct file *in, loff_t *ppos,
                         struct pipe_inode_info *pipe, size_t len,
                         unsigned int flags)
 {
+       ssize_t (*splice_read)(struct file *, loff_t *,
+                              struct pipe_inode_info *, size_t, unsigned int);
        int ret;
 
-       if (unlikely(!in->f_op || !in->f_op->splice_read))
-               return -EINVAL;
-
        if (unlikely(!(in->f_mode & FMODE_READ)))
                return -EBADF;
 
@@ -945,7 +1096,12 @@ static long do_splice_to(struct file *in, loff_t *ppos,
        if (unlikely(ret < 0))
                return ret;
 
-       return in->f_op->splice_read(in, ppos, pipe, len, flags);
+       if (in->f_op && in->f_op->splice_read)
+               splice_read = in->f_op->splice_read;
+       else
+               splice_read = default_file_splice_read;
+
+       return splice_read(in, ppos, pipe, len, flags);
 }
 
 /**
@@ -1164,7 +1320,8 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                if (off_in)
                        return -ESPIPE;
                if (off_out) {
-                       if (out->f_op->llseek == no_llseek)
+                       if (!out->f_op || !out->f_op->llseek ||
+                           out->f_op->llseek == no_llseek)
                                return -EINVAL;
                        if (copy_from_user(&offset, off_out, sizeof(loff_t)))
                                return -EFAULT;
@@ -1184,7 +1341,8 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                if (off_out)
                        return -ESPIPE;
                if (off_in) {
-                       if (in->f_op->llseek == no_llseek)
+                       if (!in->f_op || !in->f_op->llseek ||
+                           in->f_op->llseek == no_llseek)
                                return -EINVAL;
                        if (copy_from_user(&offset, off_in, sizeof(loff_t)))
                                return -EFAULT;