diff options
-rw-r--r-- | fs/fuse/file.c | 92 | ||||
-rw-r--r-- | fs/fuse/fuse_i.h | 17 |
2 files changed, 109 insertions, 0 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 1ee2fc9..4002889 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -506,6 +506,98 @@ static void fuse_release_user_pages(struct fuse_req *req, int write) } } +/** + * In case of short read, the caller sets 'pos' to the position of + * actual end of fuse request in IO request. Otherwise, if bytes_requested + * == bytes_transferred or rw == WRITE, the caller sets 'pos' to -1. + * + * An example: + * User requested DIO read of 64K. It was splitted into two 32K fuse requests, + * both submitted asynchronously. The first of them was ACKed by userspace as + * fully completed (req->out.args[0].size == 32K) resulting in pos == -1. The + * second request was ACKed as short, e.g. only 1K was read, resulting in + * pos == 33K. + * + * Thus, when all fuse requests are completed, the minimal non-negative 'pos' + * will be equal to the length of the longest contiguous fragment of + * transferred data starting from the beginning of IO request. + */ +static void fuse_aio_complete(struct fuse_io_priv *io, int err, ssize_t pos) +{ + int left; + + spin_lock(&io->lock); + if (err) + io->err = io->err ? : err; + else if (pos >= 0 && (io->bytes < 0 || pos < io->bytes)) + io->bytes = pos; + + left = --io->reqs; + spin_unlock(&io->lock); + + if (!left) { + long res; + + if (io->err) + res = io->err; + else if (io->bytes >= 0 && io->write) + res = -EIO; + else { + res = io->bytes < 0 ? io->size : io->bytes; + + if (!is_sync_kiocb(io->iocb)) { + struct path *path = &io->iocb->ki_filp->f_path; + struct inode *inode = path->dentry->d_inode; + struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_inode *fi = get_fuse_inode(inode); + + spin_lock(&fc->lock); + fi->attr_version = ++fc->attr_version; + spin_unlock(&fc->lock); + } + } + + aio_complete(io->iocb, res, 0); + kfree(io); + } +} + +static void fuse_aio_complete_req(struct fuse_conn *fc, struct fuse_req *req) +{ + struct fuse_io_priv *io = req->io; + ssize_t pos = -1; + + fuse_release_user_pages(req, !io->write); + + if (io->write) { + if (req->misc.write.in.size != req->misc.write.out.size) + pos = req->misc.write.in.offset - io->offset + + req->misc.write.out.size; + } else { + if (req->misc.read.in.size != req->out.args[0].size) + pos = req->misc.read.in.offset - io->offset + + req->out.args[0].size; + } + + fuse_aio_complete(io, req->out.h.error, pos); +} + +static size_t fuse_async_req_send(struct fuse_conn *fc, struct fuse_req *req, + size_t num_bytes, struct fuse_io_priv *io) +{ + spin_lock(&io->lock); + io->size += num_bytes; + io->reqs++; + spin_unlock(&io->lock); + + req->io = io; + req->end = fuse_aio_complete_req; + + fuse_request_send_background(fc, req); + + return num_bytes; +} + static size_t fuse_send_read(struct fuse_req *req, struct file *file, loff_t pos, size_t count, fl_owner_t owner) { diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 6bf30f2..aea0724 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -228,6 +228,20 @@ enum fuse_req_state { FUSE_REQ_FINISHED }; +/** The request IO state (for asynchronous processing) */ +struct fuse_io_priv { + int async; + spinlock_t lock; + unsigned reqs; + ssize_t bytes; + size_t size; + __u64 offset; + bool write; + int err; + struct kiocb *iocb; + struct file *file; +}; + /** * A request to the client */ @@ -332,6 +346,9 @@ struct fuse_req { /** Inode used in the request or NULL */ struct inode *inode; + /** AIO control block */ + struct fuse_io_priv *io; + /** Link on fi->writepages */ struct list_head writepages_entry; |