diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/compat.c | 4 | ||||
| -rw-r--r-- | fs/ext3/ioctl.c | 18 | ||||
| -rw-r--r-- | fs/ext3/resize.c | 2 | ||||
| -rw-r--r-- | fs/fuse/dev.c | 35 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 12 | ||||
| -rw-r--r-- | fs/fuse/inode.c | 40 | ||||
| -rw-r--r-- | fs/splice.c | 355 |
7 files changed, 348 insertions, 118 deletions
diff --git a/fs/compat.c b/fs/compat.c index 7f8e26ea427c..2e32bd340474 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -1217,6 +1217,10 @@ static ssize_t compat_do_readv_writev(int type, struct file *file, if (ret < 0) goto out; + ret = security_file_permission(file, type == READ ? MAY_READ:MAY_WRITE); + if (ret) + goto out; + fnv = NULL; if (type == READ) { fn = file->f_op->read; diff --git a/fs/ext3/ioctl.c b/fs/ext3/ioctl.c index aaf1da17b6d4..8c22aa9a7fbb 100644 --- a/fs/ext3/ioctl.c +++ b/fs/ext3/ioctl.c @@ -48,6 +48,7 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd, if (!S_ISDIR(inode->i_mode)) flags &= ~EXT3_DIRSYNC_FL; + mutex_lock(&inode->i_mutex); oldflags = ei->i_flags; /* The JOURNAL_DATA flag is modifiable only by root */ @@ -60,8 +61,10 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd, * This test looks nicer. Thanks to Pauline Middelink */ if ((flags ^ oldflags) & (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL)) { - if (!capable(CAP_LINUX_IMMUTABLE)) + if (!capable(CAP_LINUX_IMMUTABLE)) { + mutex_unlock(&inode->i_mutex); return -EPERM; + } } /* @@ -69,14 +72,18 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd, * the relevant capability. */ if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) { - if (!capable(CAP_SYS_RESOURCE)) + if (!capable(CAP_SYS_RESOURCE)) { + mutex_unlock(&inode->i_mutex); return -EPERM; + } } handle = ext3_journal_start(inode, 1); - if (IS_ERR(handle)) + if (IS_ERR(handle)) { + mutex_unlock(&inode->i_mutex); return PTR_ERR(handle); + } if (IS_SYNC(inode)) handle->h_sync = 1; err = ext3_reserve_inode_write(handle, inode, &iloc); @@ -93,11 +100,14 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd, err = ext3_mark_iloc_dirty(handle, inode, &iloc); flags_err: ext3_journal_stop(handle); - if (err) + if (err) { + mutex_unlock(&inode->i_mutex); return err; + } if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) err = ext3_change_inode_journal_flag(inode, jflag); + mutex_unlock(&inode->i_mutex); return err; } case EXT3_IOC_GETVERSION: diff --git a/fs/ext3/resize.c b/fs/ext3/resize.c index c5ffa8523968..8aac5334680d 100644 --- a/fs/ext3/resize.c +++ b/fs/ext3/resize.c @@ -213,7 +213,7 @@ static int setup_new_group_blocks(struct super_block *sb, goto exit_bh; } lock_buffer(bh); - memcpy(gdb->b_data, sbi->s_group_desc[i], bh->b_size); + memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, bh->b_size); set_buffer_uptodate(gdb); unlock_buffer(bh); ext3_journal_dirty_metadata(handle, gdb); diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index cc750c68fe70..104a62dadb94 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -128,14 +128,24 @@ void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req) } } -void fuse_remove_background(struct fuse_conn *fc, struct fuse_req *req) +/* + * Called with sbput_sem held for read (request_end) or write + * (fuse_put_super). By the time fuse_put_super() is finished, all + * inodes belonging to background requests must be released, so the + * iputs have to be done within the locked region. + */ +void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req) { - list_del_init(&req->bg_entry); + iput(req->inode); + iput(req->inode2); + spin_lock(&fc->lock); + list_del(&req->bg_entry); if (fc->num_background == FUSE_MAX_BACKGROUND) { fc->blocked = 0; wake_up_all(&fc->blocked_waitq); } fc->num_background--; + spin_unlock(&fc->lock); } /* @@ -165,27 +175,22 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req) wake_up(&req->waitq); fuse_put_request(fc, req); } else { - struct inode *inode = req->inode; - struct inode *inode2 = req->inode2; - struct file *file = req->file; void (*end) (struct fuse_conn *, struct fuse_req *) = req->end; req->end = NULL; - req->inode = NULL; - req->inode2 = NULL; - req->file = NULL; - if (!list_empty(&req->bg_entry)) - fuse_remove_background(fc, req); spin_unlock(&fc->lock); + down_read(&fc->sbput_sem); + if (fc->mounted) + fuse_release_background(fc, req); + up_read(&fc->sbput_sem); + + /* fput must go outside sbput_sem, otherwise it can deadlock */ + if (req->file) + fput(req->file); if (end) end(fc, req); else fuse_put_request(fc, req); - - if (file) - fput(file); - iput(inode); - iput(inode2); } } diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 59661c481d9d..0474202cb5dc 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -258,9 +258,15 @@ struct fuse_conn { /** waitq for blocked connection */ wait_queue_head_t blocked_waitq; + /** RW semaphore for exclusion with fuse_put_super() */ + struct rw_semaphore sbput_sem; + /** The next unique request id */ u64 reqctr; + /** Mount is active */ + unsigned mounted; + /** Connection established, cleared on umount, connection abort and device release */ unsigned connected; @@ -471,11 +477,11 @@ void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req); void request_send_background(struct fuse_conn *fc, struct fuse_req *req); /** - * Remove request from the the background list + * Release inodes and file associated with background request */ -void fuse_remove_background(struct fuse_conn *fc, struct fuse_req *req); +void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req); -/** Abort all requests */ +/* Abort all requests */ void fuse_abort_conn(struct fuse_conn *fc); /** diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 43a6fc0db8a7..7627022446b2 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -204,26 +204,17 @@ static void fuse_put_super(struct super_block *sb) { struct fuse_conn *fc = get_fuse_conn_super(sb); + down_write(&fc->sbput_sem); + while (!list_empty(&fc->background)) + fuse_release_background(fc, + list_entry(fc->background.next, + struct fuse_req, bg_entry)); + spin_lock(&fc->lock); + fc->mounted = 0; fc->connected = 0; - while (!list_empty(&fc->background)) { - struct fuse_req *req = list_entry(fc->background.next, - struct fuse_req, bg_entry); - struct inode *inode = req->inode; - struct inode *inode2 = req->inode2; - - /* File would hold a reference to vfsmount */ - BUG_ON(req->file); - req->inode = NULL; - req->inode2 = NULL; - fuse_remove_background(fc, req); - - spin_unlock(&fc->lock); - iput(inode); - iput(inode2); - spin_lock(&fc->lock); - } spin_unlock(&fc->lock); + up_write(&fc->sbput_sem); /* Flush all readers on this fs */ kill_fasync(&fc->fasync, SIGIO, POLL_IN); wake_up_all(&fc->waitq); @@ -395,6 +386,7 @@ static struct fuse_conn *new_conn(void) INIT_LIST_HEAD(&fc->processing); INIT_LIST_HEAD(&fc->io); INIT_LIST_HEAD(&fc->background); + init_rwsem(&fc->sbput_sem); kobj_set_kset_s(fc, connections_subsys); kobject_init(&fc->kobj); atomic_set(&fc->num_waiting, 0); @@ -508,11 +500,6 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) if (file->f_op != &fuse_dev_operations) return -EINVAL; - /* Setting file->private_data can't race with other mount() - instances, since BKL is held for ->get_sb() */ - if (file->private_data) - return -EINVAL; - fc = new_conn(); if (!fc) return -ENOMEM; @@ -548,7 +535,14 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) if (err) goto err_free_req; + /* Setting file->private_data can't race with other mount() + instances, since BKL is held for ->get_sb() */ + err = -EINVAL; + if (file->private_data) + goto err_kobject_del; + sb->s_root = root_dentry; + fc->mounted = 1; fc->connected = 1; kobject_get(&fc->kobj); file->private_data = fc; @@ -563,6 +557,8 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) return 0; + err_kobject_del: + kobject_del(&fc->kobj); err_free_req: fuse_request_free(init_req); err_put_root: diff --git a/fs/splice.c b/fs/splice.c index 0559e7577a04..447ebc0a37f3 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -27,15 +27,22 @@ #include <linux/buffer_head.h> #include <linux/module.h> #include <linux/syscalls.h> +#include <linux/uio.h> + +struct partial_page { + unsigned int offset; + unsigned int len; +}; /* - * Passed to the actors + * Passed to splice_to_pipe */ -struct splice_desc { - unsigned int len, total_len; /* current and remaining length */ +struct splice_pipe_desc { + struct page **pages; /* page map */ + struct partial_page *partial; /* pages[] may not be contig */ + int nr_pages; /* number of pages in map */ unsigned int flags; /* splice flags */ - struct file *file; /* file to read/write */ - loff_t pos; /* file position */ + struct pipe_buf_operations *ops;/* ops associated with output pipe */ }; /* @@ -128,6 +135,19 @@ static void page_cache_pipe_buf_unmap(struct pipe_inode_info *info, 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) { @@ -143,19 +163,33 @@ static struct pipe_buf_operations page_cache_pipe_buf_ops = { .get = page_cache_pipe_buf_get, }; +static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + return 1; +} + +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, + .release = page_cache_pipe_buf_release, + .steal = user_page_pipe_buf_steal, + .get = page_cache_pipe_buf_get, +}; + /* * Pipe output worker. This sets up our pipe format with the page cache * pipe buffer operations. Otherwise very similar to the regular pipe_writev(). */ -static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages, - int nr_pages, unsigned long len, - unsigned int offset, unsigned int flags) +static ssize_t splice_to_pipe(struct pipe_inode_info *pipe, + struct splice_pipe_desc *spd) { - int ret, do_wakeup, i; + int ret, do_wakeup, page_nr; ret = 0; do_wakeup = 0; - i = 0; + page_nr = 0; if (pipe->inode) mutex_lock(&pipe->inode->i_mutex); @@ -171,27 +205,19 @@ static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages, if (pipe->nrbufs < PIPE_BUFFERS) { int newbuf = (pipe->curbuf + pipe->nrbufs) & (PIPE_BUFFERS - 1); struct pipe_buffer *buf = pipe->bufs + newbuf; - struct page *page = pages[i++]; - unsigned long this_len; - this_len = PAGE_CACHE_SIZE - offset; - if (this_len > len) - this_len = len; - - buf->page = page; - buf->offset = offset; - buf->len = this_len; - buf->ops = &page_cache_pipe_buf_ops; + buf->page = spd->pages[page_nr]; + buf->offset = spd->partial[page_nr].offset; + buf->len = spd->partial[page_nr].len; + buf->ops = spd->ops; pipe->nrbufs++; + page_nr++; + ret += buf->len; + if (pipe->inode) do_wakeup = 1; - ret += this_len; - len -= this_len; - offset = 0; - if (!--nr_pages) - break; - if (!len) + if (!--spd->nr_pages) break; if (pipe->nrbufs < PIPE_BUFFERS) continue; @@ -199,7 +225,7 @@ static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages, break; } - if (flags & SPLICE_F_NONBLOCK) { + if (spd->flags & SPLICE_F_NONBLOCK) { if (!ret) ret = -EAGAIN; break; @@ -234,8 +260,8 @@ static ssize_t move_to_pipe(struct pipe_inode_info *pipe, struct page **pages, kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); } - while (i < nr_pages) - page_cache_release(pages[i++]); + while (page_nr < spd->nr_pages) + page_cache_release(spd->pages[page_nr++]); return ret; } @@ -246,17 +272,24 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, unsigned int flags) { struct address_space *mapping = in->f_mapping; - unsigned int loff, offset, nr_pages; + unsigned int loff, nr_pages; struct page *pages[PIPE_BUFFERS]; + struct partial_page partial[PIPE_BUFFERS]; struct page *page; pgoff_t index, end_index; loff_t isize; - size_t bytes; - int i, error; + size_t total_len; + int error; + struct splice_pipe_desc spd = { + .pages = pages, + .partial = partial, + .flags = flags, + .ops = &page_cache_pipe_buf_ops, + }; index = *ppos >> PAGE_CACHE_SHIFT; - loff = offset = *ppos & ~PAGE_CACHE_MASK; - nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + loff = *ppos & ~PAGE_CACHE_MASK; + nr_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; if (nr_pages > PIPE_BUFFERS) nr_pages = PIPE_BUFFERS; @@ -266,15 +299,15 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, * read-ahead if this is a non-zero offset (we are likely doing small * chunk splice and the page is already there) for a single page. */ - if (!offset || nr_pages > 1) - do_page_cache_readahead(mapping, in, index, nr_pages); + if (!loff || spd.nr_pages > 1) + do_page_cache_readahead(mapping, in, index, spd.nr_pages); /* * Now fill in the holes: */ error = 0; - bytes = 0; - for (i = 0; i < nr_pages; i++, index++) { + total_len = 0; + for (spd.nr_pages = 0; spd.nr_pages < nr_pages; spd.nr_pages++, index++) { unsigned int this_len; if (!len) @@ -283,7 +316,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, /* * this_len is the max we'll use from this page */ - this_len = min(len, PAGE_CACHE_SIZE - loff); + this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff); find_page: /* * lookup the page for this index @@ -367,26 +400,29 @@ readpage: */ if (end_index == index) { loff = PAGE_CACHE_SIZE - (isize & ~PAGE_CACHE_MASK); - if (bytes + loff > isize) { + if (total_len + loff > isize) { page_cache_release(page); break; } /* * force quit after adding this page */ - nr_pages = i; + nr_pages = spd.nr_pages; this_len = min(this_len, loff); + loff = 0; } } fill_it: - pages[i] = page; - bytes += this_len; + pages[spd.nr_pages] = page; + partial[spd.nr_pages].offset = loff; + partial[spd.nr_pages].len = this_len; len -= this_len; + total_len += this_len; loff = 0; } - if (i) - return move_to_pipe(pipe, pages, i, bytes, offset, flags); + if (spd.nr_pages) + return splice_to_pipe(pipe, &spd); return error; } @@ -439,14 +475,13 @@ EXPORT_SYMBOL(generic_file_splice_read); /* * Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos' - * using sendpage(). + * using sendpage(). Return the number of bytes sent. */ static int pipe_to_sendpage(struct pipe_inode_info *info, struct pipe_buffer *buf, struct splice_desc *sd) { struct file *file = sd->file; loff_t pos = sd->pos; - unsigned int offset; ssize_t ret; void *ptr; int more; @@ -461,16 +496,13 @@ static int pipe_to_sendpage(struct pipe_inode_info *info, if (IS_ERR(ptr)) return PTR_ERR(ptr); - offset = pos & ~PAGE_CACHE_MASK; more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len; - ret = file->f_op->sendpage(file, buf->page, offset, sd->len, &pos,more); + ret = file->f_op->sendpage(file, buf->page, buf->offset, sd->len, + &pos, more); buf->ops->unmap(info, buf); - if (ret == sd->len) - return 0; - - return -EIO; + return ret; } /* @@ -499,7 +531,7 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf, struct file *file = sd->file; struct address_space *mapping = file->f_mapping; gfp_t gfp_mask = mapping_gfp_mask(mapping); - unsigned int offset; + unsigned int offset, this_len; struct page *page; pgoff_t index; char *src; @@ -515,6 +547,10 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf, index = sd->pos >> PAGE_CACHE_SHIFT; offset = sd->pos & ~PAGE_CACHE_MASK; + this_len = sd->len; + if (this_len + offset > PAGE_CACHE_SIZE) + this_len = PAGE_CACHE_SIZE - offset; + /* * Reuse buf page, if SPLICE_F_MOVE is set. */ @@ -558,7 +594,7 @@ find_page: * the full page. */ if (!PageUptodate(page)) { - if (sd->len < PAGE_CACHE_SIZE) { + if (this_len < PAGE_CACHE_SIZE) { ret = mapping->a_ops->readpage(file, page); if (unlikely(ret)) goto out; @@ -582,7 +618,7 @@ find_page: } } - ret = mapping->a_ops->prepare_write(file, page, 0, sd->len); + ret = mapping->a_ops->prepare_write(file, page, offset, offset+this_len); if (ret == AOP_TRUNCATED_PAGE) { page_cache_release(page); goto find_page; @@ -592,18 +628,22 @@ find_page: if (!(buf->flags & PIPE_BUF_FLAG_STOLEN)) { char *dst = kmap_atomic(page, KM_USER0); - memcpy(dst + offset, src + buf->offset, sd->len); + memcpy(dst + offset, src + buf->offset, this_len); flush_dcache_page(page); kunmap_atomic(dst, KM_USER0); } - ret = mapping->a_ops->commit_write(file, page, 0, sd->len); + ret = mapping->a_ops->commit_write(file, page, offset, offset+this_len); 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: @@ -616,17 +656,14 @@ out_nomem: return ret; } -typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, - struct splice_desc *); - /* * Pipe input worker. Most of this logic works like a regular pipe, the * key here is the 'actor' worker passed in that actually moves the data * to the wanted destination. See pipe_to_file/pipe_to_sendpage above. */ -static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, - loff_t *ppos, size_t len, unsigned int flags, - splice_actor *actor) +ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, + loff_t *ppos, size_t len, unsigned int flags, + splice_actor *actor) { int ret, do_wakeup, err; struct splice_desc sd; @@ -652,16 +689,22 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, sd.len = sd.total_len; err = actor(pipe, buf, &sd); - if (err) { + if (err <= 0) { if (!ret && err != -ENODATA) ret = err; break; } - ret += sd.len; - buf->offset += sd.len; - buf->len -= sd.len; + ret += err; + buf->offset += err; + buf->len -= err; + + sd.len -= err; + sd.pos += err; + sd.total_len -= err; + if (sd.len) + continue; if (!buf->len) { buf->ops = NULL; @@ -672,8 +715,6 @@ static ssize_t move_from_pipe(struct pipe_inode_info *pipe, struct file *out, do_wakeup = 1; } - sd.pos += sd.len; - sd.total_len -= sd.len; if (!sd.total_len) break; } @@ -741,7 +782,7 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, struct address_space *mapping = out->f_mapping; ssize_t ret; - ret = move_from_pipe(pipe, out, ppos, len, flags, pipe_to_file); + ret = splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_file); if (ret > 0) { struct inode *inode = mapping->host; @@ -783,7 +824,7 @@ EXPORT_SYMBOL(generic_file_splice_write); ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out, loff_t *ppos, size_t len, unsigned int flags) { - return move_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage); + return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage); } EXPORT_SYMBOL(generic_splice_sendpage); @@ -870,7 +911,7 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, /* * We don't have an immediate reader, but we'll read the stuff - * out of the pipe right after the move_to_pipe(). So set + * out of the pipe right after the splice_to_pipe(). So set * PIPE_READERS appropriately. */ pipe->readers = 1; @@ -1010,6 +1051,174 @@ static long do_splice(struct file *in, loff_t __user *off_in, return -EINVAL; } +/* + * Map an iov into an array of pages and offset/length tupples. With the + * partial_page structure, we can map several non-contiguous ranges into + * our ones pages[] map instead of splitting that operation into pieces. + * Could easily be exported as a generic helper for other users, in which + * case one would probably want to add a 'max_nr_pages' parameter as well. + */ +static int get_iovec_page_array(const struct iovec __user *iov, + unsigned int nr_vecs, struct page **pages, + struct partial_page *partial) +{ + int buffers = 0, error = 0; + + /* + * It's ok to take the mmap_sem for reading, even + * across a "get_user()". + */ + down_read(¤t->mm->mmap_sem); + + while (nr_vecs) { + unsigned long off, npages; + void __user *base; + size_t len; + int i; + + /* + * Get user address base and length for this iovec. + */ + error = get_user(base, &iov->iov_base); + if (unlikely(error)) + break; + error = get_user(len, &iov->iov_len); + if (unlikely(error)) + break; + + /* + * Sanity check this iovec. 0 read succeeds. + */ + if (unlikely(!len)) + break; + error = -EFAULT; + if (unlikely(!base)) + break; + + /* + * Get this base offset and number of pages, then map + * in the user pages. + */ + off = (unsigned long) base & ~PAGE_MASK; + npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT; + if (npages > PIPE_BUFFERS - buffers) + npages = PIPE_BUFFERS - buffers; + + error = get_user_pages(current, current->mm, + (unsigned long) base, npages, 0, 0, + &pages[buffers], NULL); + + if (unlikely(error <= 0)) + break; + + /* + * Fill this contiguous range into the partial page map. + */ + for (i = 0; i < error; i++) { + const int plen = min_t(size_t, len, PAGE_SIZE) - off; + + partial[buffers].offset = off; + partial[buffers].len = plen; + + off = 0; + len -= plen; + buffers++; + } + + /* + * We didn't complete this iov, stop here since it probably + * means we have to move some of this into a pipe to + * be able to continue. + */ + if (len) + break; + + /* + * Don't continue if we mapped fewer pages than we asked for, + * or if we mapped the max number of pages that we have + * room for. + */ + if (error < npages || buffers == PIPE_BUFFERS) + break; + + nr_vecs--; + iov++; + } + + up_read(¤t->mm->mmap_sem); + + if (buffers) + return buffers; + + return error; +} + +/* + * vmsplice splices a user address range into a pipe. It can be thought of + * as splice-from-memory, where the regular splice is splice-from-file (or + * to file). In both cases the output is a pipe, naturally. + * + * Note that vmsplice only supports splicing _from_ user memory to a pipe, + * not the other way around. Splicing from user memory is a simple operation + * that can be supported without any funky alignment restrictions or nasty + * vm tricks. We simply map in the user memory and fill them into a pipe. + * The reverse isn't quite as easy, though. There are two possible solutions + * for that: + * + * - memcpy() the data internally, at which point we might as well just + * do a regular read() on the buffer anyway. + * - Lots of nasty vm tricks, that are neither fast nor flexible (it + * has restriction limitations on both ends of the pipe). + * + * Alas, it isn't here. + * + */ +static long do_vmsplice(struct file *file, const struct iovec __user *iov, + unsigned long nr_segs, unsigned int flags) +{ + struct pipe_inode_info *pipe = file->f_dentry->d_inode->i_pipe; + struct page *pages[PIPE_BUFFERS]; + struct partial_page partial[PIPE_BUFFERS]; + struct splice_pipe_desc spd = { + .pages = pages, + .partial = partial, + .flags = flags, + .ops = &user_page_pipe_buf_ops, + }; + + if (unlikely(!pipe)) + return -EBADF; + if (unlikely(nr_segs > UIO_MAXIOV)) + return -EINVAL; + else if (unlikely(!nr_segs)) + return 0; + + spd.nr_pages = get_iovec_page_array(iov, nr_segs, pages, partial); + if (spd.nr_pages <= 0) + return spd.nr_pages; + + return splice_to_pipe(pipe, &spd); +} + +asmlinkage long sys_vmsplice(int fd, const struct iovec __user *iov, + unsigned long nr_segs, unsigned int flags) +{ + struct file *file; + long error; + int fput; + + error = -EBADF; + file = fget_light(fd, &fput); + if (file) { + if (file->f_mode & FMODE_WRITE) + error = do_vmsplice(file, iov, nr_segs, flags); + + fput_light(file, fput); + } + + return error; +} + asmlinkage long sys_splice(int fd_in, loff_t __user *off_in, int fd_out, loff_t __user *off_out, size_t len, unsigned int flags) |