diff options
Diffstat (limited to 'fs/splice.c')
| -rw-r--r-- | fs/splice.c | 243 |
1 files changed, 155 insertions, 88 deletions
diff --git a/fs/splice.c b/fs/splice.c index d983d375ff11..218e24b1ac40 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -201,7 +201,8 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe, unsigned int tail = pipe->tail; unsigned int head = pipe->head; unsigned int mask = pipe->ring_size - 1; - int ret = 0, page_nr = 0; + ssize_t ret = 0; + int page_nr = 0; if (!spd_pages) return 0; @@ -673,10 +674,13 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, .u.file = out, }; int nbufs = pipe->max_usage; - struct bio_vec *array = kcalloc(nbufs, sizeof(struct bio_vec), - GFP_KERNEL); + struct bio_vec *array; ssize_t ret; + if (!out->f_op->write_iter) + return -EINVAL; + + array = kcalloc(nbufs, sizeof(struct bio_vec), GFP_KERNEL); if (unlikely(!array)) return -ENOMEM; @@ -684,6 +688,7 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, splice_from_pipe_begin(&sd); while (sd.total_len) { + struct kiocb kiocb; struct iov_iter from; unsigned int head, tail, mask; size_t left; @@ -733,7 +738,10 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, } iov_iter_bvec(&from, ITER_SOURCE, array, n, sd.total_len - left); - ret = vfs_iter_write(out, &from, &sd.pos, 0); + init_sync_kiocb(&kiocb, out); + kiocb.ki_pos = sd.pos; + ret = call_write_iter(out, &kiocb, &from); + sd.pos = kiocb.ki_pos; if (ret <= 0) break; @@ -925,8 +933,8 @@ static int warn_unsupported(struct file *file, const char *op) /* * Attempt to initiate a splice from pipe to file. */ -static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, - loff_t *ppos, size_t len, unsigned int flags) +static ssize_t do_splice_from(struct pipe_inode_info *pipe, struct file *out, + loff_t *ppos, size_t len, unsigned int flags) { if (unlikely(!out->f_op->splice_write)) return warn_unsupported(out, "write"); @@ -944,27 +952,15 @@ static void do_splice_eof(struct splice_desc *sd) sd->splice_eof(sd); } -/** - * vfs_splice_read - Read data from a file and splice it into a pipe - * @in: File to splice from - * @ppos: Input file offset - * @pipe: Pipe to splice to - * @len: Number of bytes to splice - * @flags: Splice modifier flags (SPLICE_F_*) - * - * Splice the requested amount of data from the input file to the pipe. This - * is synchronous as the caller must hold the pipe lock across the entire - * operation. - * - * If successful, it returns the amount of data spliced, 0 if it hit the EOF or - * a hole and a negative error code otherwise. +/* + * Callers already called rw_verify_area() on the entire range. + * No need to call it for sub ranges. */ -long vfs_splice_read(struct file *in, loff_t *ppos, - struct pipe_inode_info *pipe, size_t len, - unsigned int flags) +static ssize_t do_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) { unsigned int p_space; - int ret; if (unlikely(!(in->f_mode & FMODE_READ))) return -EBADF; @@ -975,10 +971,6 @@ long vfs_splice_read(struct file *in, loff_t *ppos, p_space = pipe->max_usage - pipe_occupancy(pipe->head, pipe->tail); len = min_t(size_t, len, p_space << PAGE_SHIFT); - ret = rw_verify_area(READ, in, ppos, len); - if (unlikely(ret < 0)) - return ret; - if (unlikely(len > MAX_RW_COUNT)) len = MAX_RW_COUNT; @@ -992,6 +984,34 @@ long vfs_splice_read(struct file *in, loff_t *ppos, return copy_splice_read(in, ppos, pipe, len, flags); return in->f_op->splice_read(in, ppos, pipe, len, flags); } + +/** + * vfs_splice_read - Read data from a file and splice it into a pipe + * @in: File to splice from + * @ppos: Input file offset + * @pipe: Pipe to splice to + * @len: Number of bytes to splice + * @flags: Splice modifier flags (SPLICE_F_*) + * + * Splice the requested amount of data from the input file to the pipe. This + * is synchronous as the caller must hold the pipe lock across the entire + * operation. + * + * If successful, it returns the amount of data spliced, 0 if it hit the EOF or + * a hole and a negative error code otherwise. + */ +ssize_t vfs_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + ssize_t ret; + + ret = rw_verify_area(READ, in, ppos, len); + if (unlikely(ret < 0)) + return ret; + + return do_splice_read(in, ppos, pipe, len, flags); +} EXPORT_SYMBOL_GPL(vfs_splice_read); /** @@ -1011,7 +1031,7 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, splice_direct_actor *actor) { struct pipe_inode_info *pipe; - long ret, bytes; + ssize_t ret, bytes; size_t len; int i, flags, more; @@ -1066,7 +1086,7 @@ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, size_t read_len; loff_t pos = sd->pos, prev_pos = pos; - ret = vfs_splice_read(in, &pos, pipe, len, flags); + ret = do_splice_read(in, &pos, pipe, len, flags); if (unlikely(ret <= 0)) goto read_failure; @@ -1138,9 +1158,20 @@ static int direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd) { struct file *file = sd->u.file; + long ret; + + file_start_write(file); + ret = do_splice_from(pipe, file, sd->opos, sd->total_len, sd->flags); + file_end_write(file); + return ret; +} + +static int splice_file_range_actor(struct pipe_inode_info *pipe, + struct splice_desc *sd) +{ + struct file *file = sd->u.file; - return do_splice_from(pipe, file, sd->opos, sd->total_len, - sd->flags); + return do_splice_from(pipe, file, sd->opos, sd->total_len, sd->flags); } static void direct_file_splice_eof(struct splice_desc *sd) @@ -1151,24 +1182,10 @@ static void direct_file_splice_eof(struct splice_desc *sd) file->f_op->splice_eof(file); } -/** - * do_splice_direct - splices data directly between two files - * @in: file to splice from - * @ppos: input file offset - * @out: file to splice to - * @opos: output file offset - * @len: number of bytes to splice - * @flags: splice modifier flags - * - * Description: - * For use by do_sendfile(). splice can easily emulate sendfile, but - * doing it in the application would incur an extra system call - * (splice in + splice out, as compared to just sendfile()). So this helper - * can splice directly through a process-private pipe. - * - */ -long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, - loff_t *opos, size_t len, unsigned int flags) +static ssize_t do_splice_direct_actor(struct file *in, loff_t *ppos, + struct file *out, loff_t *opos, + size_t len, unsigned int flags, + splice_direct_actor *actor) { struct splice_desc sd = { .len = len, @@ -1179,7 +1196,7 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, .splice_eof = direct_file_splice_eof, .opos = opos, }; - long ret; + ssize_t ret; if (unlikely(!(out->f_mode & FMODE_WRITE))) return -EBADF; @@ -1187,18 +1204,63 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, if (unlikely(out->f_flags & O_APPEND)) return -EINVAL; - ret = rw_verify_area(WRITE, out, opos, len); - if (unlikely(ret < 0)) - return ret; - - ret = splice_direct_to_actor(in, &sd, direct_splice_actor); + ret = splice_direct_to_actor(in, &sd, actor); if (ret > 0) *ppos = sd.pos; return ret; } +/** + * do_splice_direct - splices data directly between two files + * @in: file to splice from + * @ppos: input file offset + * @out: file to splice to + * @opos: output file offset + * @len: number of bytes to splice + * @flags: splice modifier flags + * + * Description: + * For use by do_sendfile(). splice can easily emulate sendfile, but + * doing it in the application would incur an extra system call + * (splice in + splice out, as compared to just sendfile()). So this helper + * can splice directly through a process-private pipe. + * + * Callers already called rw_verify_area() on the entire range. + */ +ssize_t do_splice_direct(struct file *in, loff_t *ppos, struct file *out, + loff_t *opos, size_t len, unsigned int flags) +{ + return do_splice_direct_actor(in, ppos, out, opos, len, flags, + direct_splice_actor); +} EXPORT_SYMBOL(do_splice_direct); +/** + * splice_file_range - splices data between two files for copy_file_range() + * @in: file to splice from + * @ppos: input file offset + * @out: file to splice to + * @opos: output file offset + * @len: number of bytes to splice + * + * Description: + * For use by ->copy_file_range() methods. + * Like do_splice_direct(), but vfs_copy_file_range() already holds + * start_file_write() on @out file. + * + * Callers already called rw_verify_area() on the entire range. + */ +ssize_t splice_file_range(struct file *in, loff_t *ppos, struct file *out, + loff_t *opos, size_t len) +{ + lockdep_assert(file_write_started(out)); + + return do_splice_direct_actor(in, ppos, out, opos, + min_t(size_t, len, MAX_RW_COUNT), + 0, splice_file_range_actor); +} +EXPORT_SYMBOL(splice_file_range); + static int wait_for_space(struct pipe_inode_info *pipe, unsigned flags) { for (;;) { @@ -1220,17 +1282,17 @@ static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe, struct pipe_inode_info *opipe, size_t len, unsigned int flags); -long splice_file_to_pipe(struct file *in, - struct pipe_inode_info *opipe, - loff_t *offset, - size_t len, unsigned int flags) +ssize_t splice_file_to_pipe(struct file *in, + struct pipe_inode_info *opipe, + loff_t *offset, + size_t len, unsigned int flags) { - long ret; + ssize_t ret; pipe_lock(opipe); ret = wait_for_space(opipe, flags); if (!ret) - ret = vfs_splice_read(in, offset, opipe, len, flags); + ret = do_splice_read(in, offset, opipe, len, flags); pipe_unlock(opipe); if (ret > 0) wakeup_pipe_readers(opipe); @@ -1240,13 +1302,13 @@ long splice_file_to_pipe(struct file *in, /* * Determine where to splice to/from. */ -long do_splice(struct file *in, loff_t *off_in, struct file *out, - loff_t *off_out, size_t len, unsigned int flags) +ssize_t do_splice(struct file *in, loff_t *off_in, struct file *out, + loff_t *off_out, size_t len, unsigned int flags) { struct pipe_inode_info *ipipe; struct pipe_inode_info *opipe; loff_t offset; - long ret; + ssize_t ret; if (unlikely(!(in->f_mode & FMODE_READ) || !(out->f_mode & FMODE_WRITE))) @@ -1307,6 +1369,10 @@ long do_splice(struct file *in, loff_t *off_in, struct file *out, offset = in->f_pos; } + ret = rw_verify_area(READ, in, &offset, len); + if (unlikely(ret < 0)) + return ret; + if (out->f_flags & O_NONBLOCK) flags |= SPLICE_F_NONBLOCK; @@ -1333,14 +1399,14 @@ long do_splice(struct file *in, loff_t *off_in, struct file *out, return ret; } -static long __do_splice(struct file *in, loff_t __user *off_in, - struct file *out, loff_t __user *off_out, - size_t len, unsigned int flags) +static ssize_t __do_splice(struct file *in, loff_t __user *off_in, + struct file *out, loff_t __user *off_out, + size_t len, unsigned int flags) { struct pipe_inode_info *ipipe; struct pipe_inode_info *opipe; loff_t offset, *__off_in = NULL, *__off_out = NULL; - long ret; + ssize_t ret; ipipe = get_pipe_info(in, true); opipe = get_pipe_info(out, true); @@ -1379,16 +1445,16 @@ static long __do_splice(struct file *in, loff_t __user *off_in, return ret; } -static int iter_to_pipe(struct iov_iter *from, - struct pipe_inode_info *pipe, - unsigned flags) +static ssize_t iter_to_pipe(struct iov_iter *from, + struct pipe_inode_info *pipe, + unsigned int flags) { struct pipe_buffer buf = { .ops = &user_page_pipe_buf_ops, .flags = flags }; size_t total = 0; - int ret = 0; + ssize_t ret = 0; while (iov_iter_count(from)) { struct page *pages[16]; @@ -1437,8 +1503,8 @@ static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf, * For lack of a better implementation, implement vmsplice() to userspace * as a simple copy of the pipes pages to the user iov. */ -static long vmsplice_to_user(struct file *file, struct iov_iter *iter, - unsigned int flags) +static ssize_t vmsplice_to_user(struct file *file, struct iov_iter *iter, + unsigned int flags) { struct pipe_inode_info *pipe = get_pipe_info(file, true); struct splice_desc sd = { @@ -1446,7 +1512,7 @@ static long vmsplice_to_user(struct file *file, struct iov_iter *iter, .flags = flags, .u.data = iter }; - long ret = 0; + ssize_t ret = 0; if (!pipe) return -EBADF; @@ -1470,11 +1536,11 @@ static long vmsplice_to_user(struct file *file, struct iov_iter *iter, * as splice-from-memory, where the regular splice is splice-from-file (or * to file). In both cases the output is a pipe, naturally. */ -static long vmsplice_to_pipe(struct file *file, struct iov_iter *iter, - unsigned int flags) +static ssize_t vmsplice_to_pipe(struct file *file, struct iov_iter *iter, + unsigned int flags) { struct pipe_inode_info *pipe; - long ret = 0; + ssize_t ret = 0; unsigned buf_flag = 0; if (flags & SPLICE_F_GIFT) @@ -1570,7 +1636,7 @@ SYSCALL_DEFINE6(splice, int, fd_in, loff_t __user *, off_in, size_t, len, unsigned int, flags) { struct fd in, out; - long error; + ssize_t error; if (unlikely(!len)) return 0; @@ -1584,7 +1650,7 @@ SYSCALL_DEFINE6(splice, int, fd_in, loff_t __user *, off_in, out = fdget(fd_out); if (out.file) { error = __do_splice(in.file, off_in, out.file, off_out, - len, flags); + len, flags); fdput(out); } fdput(in); @@ -1807,15 +1873,15 @@ retry: /* * Link contents of ipipe to opipe. */ -static int link_pipe(struct pipe_inode_info *ipipe, - struct pipe_inode_info *opipe, - size_t len, unsigned int flags) +static ssize_t link_pipe(struct pipe_inode_info *ipipe, + struct pipe_inode_info *opipe, + size_t len, unsigned int flags) { struct pipe_buffer *ibuf, *obuf; unsigned int i_head, o_head; unsigned int i_tail, o_tail; unsigned int i_mask, o_mask; - int ret = 0; + ssize_t ret = 0; /* * Potential ABBA deadlock, work around it by ordering lock @@ -1898,11 +1964,12 @@ static int link_pipe(struct pipe_inode_info *ipipe, * The 'flags' used are the SPLICE_F_* variants, currently the only * applicable one is SPLICE_F_NONBLOCK. */ -long do_tee(struct file *in, struct file *out, size_t len, unsigned int flags) +ssize_t do_tee(struct file *in, struct file *out, size_t len, + unsigned int flags) { struct pipe_inode_info *ipipe = get_pipe_info(in, true); struct pipe_inode_info *opipe = get_pipe_info(out, true); - int ret = -EINVAL; + ssize_t ret = -EINVAL; if (unlikely(!(in->f_mode & FMODE_READ) || !(out->f_mode & FMODE_WRITE))) @@ -1939,7 +2006,7 @@ long do_tee(struct file *in, struct file *out, size_t len, unsigned int flags) SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags) { struct fd in, out; - int error; + ssize_t error; if (unlikely(flags & ~SPLICE_F_ALL)) return -EINVAL; |