diff options
| -rw-r--r-- | fs/pipe.c | 31 | ||||
| -rw-r--r-- | include/linux/pipe_fs_i.h | 1 |
2 files changed, 30 insertions, 2 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index da42f7db50d..0499a96287a 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -345,6 +345,16 @@ static const struct pipe_buf_operations anon_pipe_buf_ops = { .get = generic_pipe_buf_get, }; +static const struct pipe_buf_operations packet_pipe_buf_ops = { + .can_merge = 0, + .map = generic_pipe_buf_map, + .unmap = generic_pipe_buf_unmap, + .confirm = generic_pipe_buf_confirm, + .release = anon_pipe_buf_release, + .steal = generic_pipe_buf_steal, + .get = generic_pipe_buf_get, +}; + static ssize_t pipe_read(struct kiocb *iocb, const struct iovec *_iov, unsigned long nr_segs, loff_t pos) @@ -406,6 +416,13 @@ redo: ret += chars; buf->offset += chars; buf->len -= chars; + + /* Was it a packet buffer? Clean up and exit */ + if (buf->flags & PIPE_BUF_FLAG_PACKET) { + total_len = chars; + buf->len = 0; + } + if (!buf->len) { buf->ops = NULL; ops->release(pipe, buf); @@ -458,6 +475,11 @@ redo: return ret; } +static inline int is_packetized(struct file *file) +{ + return (file->f_flags & O_DIRECT) != 0; +} + static ssize_t pipe_write(struct kiocb *iocb, const struct iovec *_iov, unsigned long nr_segs, loff_t ppos) @@ -592,6 +614,11 @@ redo2: buf->ops = &anon_pipe_buf_ops; buf->offset = 0; buf->len = chars; + buf->flags = 0; + if (is_packetized(filp)) { + buf->ops = &packet_pipe_buf_ops; + buf->flags = PIPE_BUF_FLAG_PACKET; + } pipe->nrbufs = ++bufs; pipe->tmp_page = NULL; @@ -1012,7 +1039,7 @@ struct file *create_write_pipe(int flags) goto err_dentry; f->f_mapping = inode->i_mapping; - f->f_flags = O_WRONLY | (flags & O_NONBLOCK); + f->f_flags = O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT)); f->f_version = 0; return f; @@ -1056,7 +1083,7 @@ int do_pipe_flags(int *fd, int flags) int error; int fdw, fdr; - if (flags & ~(O_CLOEXEC | O_NONBLOCK)) + if (flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT)) return -EINVAL; fw = create_write_pipe(flags); diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index 77257c92155..0072a5366e9 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -8,6 +8,7 @@ #define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */ #define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */ #define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */ +#define PIPE_BUF_FLAG_PACKET 0x08 /* read() as a packet */ /** * struct pipe_buffer - a linux kernel pipe buffer |