diff options
| -rw-r--r-- | fs/pipe.c | 39 | ||||
| -rw-r--r-- | fs/splice.c | 91 | ||||
| -rw-r--r-- | include/linux/pipe_fs_i.h | 21 |
3 files changed, 73 insertions, 78 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index 888f265011b..d9644fd9cc0 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -110,14 +110,14 @@ static void anon_pipe_buf_release(struct pipe_inode_info *pipe, page_cache_release(page); } -static void * anon_pipe_buf_map(struct file *file, struct pipe_inode_info *pipe, - struct pipe_buffer *buf) +void *generic_pipe_buf_map(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) { return kmap(buf->page); } -static void anon_pipe_buf_unmap(struct pipe_inode_info *pipe, - struct pipe_buffer *buf) +void generic_pipe_buf_unmap(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) { kunmap(buf->page); } @@ -135,19 +135,24 @@ static int anon_pipe_buf_steal(struct pipe_inode_info *pipe, return 1; } -static void anon_pipe_buf_get(struct pipe_inode_info *info, - struct pipe_buffer *buf) +void generic_pipe_buf_get(struct pipe_inode_info *info, struct pipe_buffer *buf) { page_cache_get(buf->page); } +int generic_pipe_buf_pin(struct pipe_inode_info *info, struct pipe_buffer *buf) +{ + return 0; +} + static struct pipe_buf_operations anon_pipe_buf_ops = { .can_merge = 1, - .map = anon_pipe_buf_map, - .unmap = anon_pipe_buf_unmap, + .map = generic_pipe_buf_map, + .unmap = generic_pipe_buf_unmap, + .pin = generic_pipe_buf_pin, .release = anon_pipe_buf_release, .steal = anon_pipe_buf_steal, - .get = anon_pipe_buf_get, + .get = generic_pipe_buf_get, }; static ssize_t @@ -183,12 +188,14 @@ pipe_readv(struct file *filp, const struct iovec *_iov, if (chars > total_len) chars = total_len; - addr = ops->map(filp, pipe, buf); - if (IS_ERR(addr)) { + error = ops->pin(pipe, buf); + if (error) { if (!ret) - ret = PTR_ERR(addr); + error = ret; break; } + + addr = ops->map(pipe, buf); error = pipe_iov_copy_to_user(iov, addr + buf->offset, chars); ops->unmap(pipe, buf); if (unlikely(error)) { @@ -300,11 +307,11 @@ pipe_writev(struct file *filp, const struct iovec *_iov, void *addr; int error; - addr = ops->map(filp, pipe, buf); - if (IS_ERR(addr)) { - error = PTR_ERR(addr); + error = ops->pin(pipe, buf); + if (error) goto out; - } + + addr = ops->map(pipe, buf); error = pipe_iov_copy_from_user(offset + addr, iov, chars); ops->unmap(pipe, buf); diff --git a/fs/splice.c b/fs/splice.c index 1633778f365..d7538d83c36 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -90,9 +90,8 @@ static void page_cache_pipe_buf_release(struct pipe_inode_info *info, 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; @@ -118,49 +117,25 @@ 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, @@ -171,11 +146,12 @@ static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, 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, }; /* @@ -517,26 +493,16 @@ 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; + int ret, 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); - - 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 +535,14 @@ 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; @@ -666,11 +631,16 @@ find_page: goto out; if (buf->page != page) { - char *dst = kmap_atomic(page, KM_USER0); + /* + * Careful, ->map() uses KM_USER0! + */ + char *src = buf->ops->map(info, buf); + 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); } ret = mapping->a_ops->commit_write(file, page, offset, offset+this_len); @@ -690,7 +660,6 @@ out: page_cache_release(page); unlock_page(page); out_nomem: - buf->ops->unmap(info, buf); return ret; } diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index 3130977fc6a..b8aae1fc518 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -14,10 +14,23 @@ struct pipe_buffer { unsigned int flags; }; +/* + * Note on the nesting of these functions: + * + * ->pin() + * ->steal() + * ... + * ->map() + * ... + * ->unmap() + * + * That is, ->map() must be called on a pinned buffer, same goes for ->steal(). + */ struct pipe_buf_operations { int can_merge; - void * (*map)(struct file *, struct pipe_inode_info *, struct pipe_buffer *); + void * (*map)(struct pipe_inode_info *, struct pipe_buffer *); void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *); + int (*pin)(struct pipe_inode_info *, struct pipe_buffer *); void (*release)(struct pipe_inode_info *, struct pipe_buffer *); int (*steal)(struct pipe_inode_info *, struct pipe_buffer *); void (*get)(struct pipe_inode_info *, struct pipe_buffer *); @@ -50,6 +63,12 @@ struct pipe_inode_info * alloc_pipe_info(struct inode * inode); void free_pipe_info(struct inode * inode); void __free_pipe_info(struct pipe_inode_info *); +/* Generic pipe buffer ops functions */ +void *generic_pipe_buf_map(struct pipe_inode_info *, struct pipe_buffer *); +void generic_pipe_buf_unmap(struct pipe_inode_info *, struct pipe_buffer *); +void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *); +int generic_pipe_buf_pin(struct pipe_inode_info *, struct pipe_buffer *); + /* * splice is tied to pipes as a transport (at least for now), so we'll just * add the splice flags here. |