X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fsplice.c;h=4ed0ba44a966ce053cdf11475333f4bdb0bb73b4;hb=7ef0d7377cb287e08f3ae94cebc919448e1f5dff;hp=56b802bfbfa4879021cc2af03f175e69cec621d8;hpb=c43e259cc756ece387faae849af0058b56d78466;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/splice.c b/fs/splice.c index 56b802b..4ed0ba4 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -58,8 +59,8 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe, */ wait_on_page_writeback(page); - if (PagePrivate(page)) - try_to_release_page(page, GFP_KERNEL); + if (PagePrivate(page) && !try_to_release_page(page, GFP_KERNEL)) + goto out_unlock; /* * If we succeeded in removing the mapping, set LRU flag @@ -75,6 +76,7 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe, * Raced with truncate or failed to remove page from current * address space, unlock and return failure. */ +out_unlock: unlock_page(page); return 1; } @@ -254,11 +256,16 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe, } while (page_nr < spd_pages) - page_cache_release(spd->pages[page_nr++]); + spd->spd_release(spd, page_nr++); return ret; } +static void spd_release_page(struct splice_pipe_desc *spd, unsigned int i) +{ + page_cache_release(spd->pages[i]); +} + static int __generic_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, @@ -277,6 +284,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, .partial = partial, .flags = flags, .ops = &page_cache_pipe_buf_ops, + .spd_release = spd_release_page, }; index = *ppos >> PAGE_CACHE_SHIFT; @@ -314,7 +322,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, break; error = add_to_page_cache_lru(page, mapping, index, - GFP_KERNEL); + mapping_gfp_mask(mapping)); if (unlikely(error)) { page_cache_release(page); if (error == -EEXIST) @@ -364,19 +372,30 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, * for an in-flight io page */ if (flags & SPLICE_F_NONBLOCK) { - if (TestSetPageLocked(page)) + if (!trylock_page(page)) { + error = -EAGAIN; break; + } } else lock_page(page); /* - * page was truncated, stop here. if this isn't the - * first page, we'll just complete what we already - * added + * Page was truncated, or invalidated by the + * filesystem. Redo the find/create, but this time the + * page is kept locked, so there's no chance of another + * race with truncate/invalidate. */ if (!page->mapping) { unlock_page(page); - break; + page = find_or_create_page(mapping, index, + mapping_gfp_mask(mapping)); + + if (!page) { + error = -ENOMEM; + break; + } + page_cache_release(pages[page_nr]); + pages[page_nr] = page; } /* * page was already under io and is now done, great @@ -473,9 +492,8 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) { - ssize_t spliced; - int ret; loff_t isize, left; + int ret; isize = i_size_read(in->f_mapping->host); if (unlikely(*ppos >= isize)) @@ -485,29 +503,9 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, if (unlikely(left < len)) len = left; - ret = 0; - spliced = 0; - while (len && !spliced) { - ret = __generic_file_splice_read(in, ppos, pipe, len, flags); - - if (ret < 0) - break; - else if (!ret) { - if (spliced) - break; - if (flags & SPLICE_F_NONBLOCK) { - ret = -EAGAIN; - break; - } - } - + ret = __generic_file_splice_read(in, ppos, pipe, len, flags); + if (ret > 0) *ppos += ret; - len -= ret; - spliced += ret; - } - - if (spliced) - return spliced; return ret; } @@ -734,8 +732,8 @@ ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, }; /* - * The actor worker might be calling ->prepare_write and - * ->commit_write. Most of the time, these expect i_mutex to + * The actor worker might be calling ->write_begin and + * ->write_end. Most of the time, these expect i_mutex to * be held. Since this may result in an ABBA deadlock with * pipe->inode, we have to order lock acquiry here. */ @@ -775,7 +773,7 @@ generic_file_splice_write_nolock(struct pipe_inode_info *pipe, struct file *out, ssize_t ret; int err; - err = remove_suid(out->f_path.dentry); + err = file_remove_suid(out); if (unlikely(err)) return err; @@ -824,24 +822,19 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, { struct address_space *mapping = out->f_mapping; struct inode *inode = mapping->host; - int killsuid, killpriv; + struct splice_desc sd = { + .total_len = len, + .flags = flags, + .pos = *ppos, + .u.file = out, + }; ssize_t ret; - int err = 0; - - killpriv = security_inode_need_killpriv(out->f_path.dentry); - killsuid = should_remove_suid(out->f_path.dentry); - if (unlikely(killsuid || killpriv)) { - mutex_lock(&inode->i_mutex); - if (killpriv) - err = security_inode_killpriv(out->f_path.dentry); - if (!err && killsuid) - err = __remove_suid(out->f_path.dentry, killsuid); - mutex_unlock(&inode->i_mutex); - if (err) - return err; - } - ret = splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_file); + inode_double_lock(inode, pipe->inode); + ret = file_remove_suid(out); + if (likely(!ret)) + ret = __splice_from_pipe(pipe, &sd, pipe_to_file); + inode_double_unlock(inode, pipe->inode); if (ret > 0) { unsigned long nr_pages; @@ -853,6 +846,8 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, * 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); @@ -904,6 +899,9 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, if (unlikely(!(out->f_mode & FMODE_WRITE))) return -EBADF; + if (unlikely(out->f_flags & O_APPEND)) + return -EINVAL; + ret = rw_verify_area(WRITE, out, ppos, len); if (unlikely(ret < 0)) return ret; @@ -999,7 +997,7 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, while (len) { size_t read_len; - loff_t pos = sd->pos; + loff_t pos = sd->pos, prev_pos = pos; ret = do_splice_to(in, &pos, pipe, len, flags); if (unlikely(ret <= 0)) @@ -1014,18 +1012,24 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, * could get stuck data in the internal pipe: */ ret = actor(pipe, sd); - if (unlikely(ret <= 0)) + if (unlikely(ret <= 0)) { + sd->pos = prev_pos; goto out_release; + } bytes += ret; len -= ret; sd->pos = pos; - if (ret < read_len) + if (ret < read_len) { + sd->pos = prev_pos + ret; goto out_release; + } } +done: pipe->nrbufs = pipe->curbuf = 0; + file_accessed(in); return bytes; out_release: @@ -1041,16 +1045,11 @@ out_release: buf->ops = NULL; } } - pipe->nrbufs = pipe->curbuf = 0; - /* - * If we transferred some data, return the number of bytes: - */ - if (bytes > 0) - return bytes; - - return ret; + if (!bytes) + bytes = ret; + goto done; } EXPORT_SYMBOL(splice_direct_to_actor); @@ -1091,7 +1090,7 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, ret = splice_direct_to_actor(in, &sd, direct_splice_actor); if (ret > 0) - *ppos += ret; + *ppos = sd.pos; return ret; } @@ -1166,33 +1165,6 @@ static long do_splice(struct file *in, loff_t __user *off_in, } /* - * Do a copy-from-user while holding the mmap_semaphore for reading, in a - * manner safe from deadlocking with simultaneous mmap() (grabbing mmap_sem - * for writing) and page faulting on the user memory pointed to by src. - * This assumes that we will very rarely hit the partial != 0 path, or this - * will not be a win. - */ -static int copy_from_user_mmap_sem(void *dst, const void __user *src, size_t n) -{ - int partial; - - pagefault_disable(); - partial = __copy_from_user_inatomic(dst, src, n); - pagefault_enable(); - - /* - * Didn't copy everything, drop the mmap_sem and do a faulting copy - */ - if (unlikely(partial)) { - up_read(¤t->mm->mmap_sem); - partial = copy_from_user(dst, src, n); - down_read(¤t->mm->mmap_sem); - } - - return partial; -} - -/* * 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. @@ -1205,8 +1177,6 @@ static int get_iovec_page_array(const struct iovec __user *iov, { int buffers = 0, error = 0; - down_read(¤t->mm->mmap_sem); - while (nr_vecs) { unsigned long off, npages; struct iovec entry; @@ -1215,7 +1185,7 @@ static int get_iovec_page_array(const struct iovec __user *iov, int i; error = -EFAULT; - if (copy_from_user_mmap_sem(&entry, iov, sizeof(entry))) + if (copy_from_user(&entry, iov, sizeof(entry))) break; base = entry.iov_base; @@ -1228,7 +1198,7 @@ static int get_iovec_page_array(const struct iovec __user *iov, if (unlikely(!len)) break; error = -EFAULT; - if (unlikely(!base)) + if (!access_ok(VERIFY_READ, base, len)) break; /* @@ -1249,9 +1219,8 @@ static int get_iovec_page_array(const struct iovec __user *iov, 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); + error = get_user_pages_fast((unsigned long)base, npages, + 0, &pages[buffers]); if (unlikely(error <= 0)) break; @@ -1290,8 +1259,6 @@ static int get_iovec_page_array(const struct iovec __user *iov, iov++; } - up_read(¤t->mm->mmap_sem); - if (buffers) return buffers; @@ -1384,6 +1351,11 @@ static long vmsplice_to_user(struct file *file, const struct iovec __user *iov, break; } + if (unlikely(!access_ok(VERIFY_WRITE, base, len))) { + error = -EFAULT; + break; + } + sd.len = 0; sd.total_len = len; sd.flags = flags; @@ -1432,6 +1404,7 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov, .partial = partial, .flags = flags, .ops = &user_page_pipe_buf_ops, + .spd_release = spd_release_page, }; pipe = pipe_info(file->f_path.dentry->d_inode); @@ -1462,8 +1435,8 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov, * Currently we punt and implement it as a normal copy, see pipe_to_user(). * */ -asmlinkage long sys_vmsplice(int fd, const struct iovec __user *iov, - unsigned long nr_segs, unsigned int flags) +SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, iov, + unsigned long, nr_segs, unsigned int, flags) { struct file *file; long error; @@ -1488,9 +1461,9 @@ asmlinkage long sys_vmsplice(int fd, const struct iovec __user *iov, 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) +SYSCALL_DEFINE6(splice, int, fd_in, loff_t __user *, off_in, + int, fd_out, loff_t __user *, off_out, + size_t, len, unsigned int, flags) { long error; struct file *in, *out; @@ -1657,6 +1630,13 @@ static int link_pipe(struct pipe_inode_info *ipipe, i++; } while (len); + /* + * return EAGAIN if we have the potential of some data in the + * future, otherwise just return 0 + */ + if (!ret && ipipe->waiting_writers && (flags & SPLICE_F_NONBLOCK)) + ret = -EAGAIN; + inode_double_unlock(ipipe->inode, opipe->inode); /* @@ -1697,18 +1677,15 @@ static long do_tee(struct file *in, struct file *out, size_t len, ret = link_ipipe_prep(ipipe, flags); if (!ret) { ret = link_opipe_prep(opipe, flags); - if (!ret) { + if (!ret) ret = link_pipe(ipipe, opipe, len, flags); - if (!ret && (flags & SPLICE_F_NONBLOCK)) - ret = -EAGAIN; - } } } return ret; } -asmlinkage long sys_tee(int fdin, int fdout, size_t len, unsigned int flags) +SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags) { struct file *in; int error, fput_in;