diff options
Diffstat (limited to 'io_uring/rw.c')
| -rw-r--r-- | io_uring/rw.c | 67 |
1 files changed, 45 insertions, 22 deletions
diff --git a/io_uring/rw.c b/io_uring/rw.c index f023ff49c688..155938f10093 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -31,9 +31,19 @@ struct io_rw { rwf_t flags; }; -static inline bool io_file_supports_nowait(struct io_kiocb *req) +static bool io_file_supports_nowait(struct io_kiocb *req, __poll_t mask) { - return req->flags & REQ_F_SUPPORT_NOWAIT; + /* If FMODE_NOWAIT is set for a file, we're golden */ + if (req->flags & REQ_F_SUPPORT_NOWAIT) + return true; + /* No FMODE_NOWAIT, if we can poll, check the status */ + if (io_file_can_poll(req)) { + struct poll_table_struct pt = { ._key = mask }; + + return vfs_poll(req->file, &pt) & mask; + } + /* No FMODE_NOWAIT support, and file isn't pollable. Tough luck. */ + return false; } #ifdef CONFIG_COMPAT @@ -796,8 +806,8 @@ static int io_rw_init_file(struct io_kiocb *req, fmode_t mode, int rw_type) * supports async. Otherwise it's impossible to use O_NONBLOCK files * reliably. If not, or it IOCB_NOWAIT is set, don't retry. */ - if ((kiocb->ki_flags & IOCB_NOWAIT) || - ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req))) + if (kiocb->ki_flags & IOCB_NOWAIT || + ((file->f_flags & O_NONBLOCK && !(req->flags & REQ_F_SUPPORT_NOWAIT)))) req->flags |= REQ_F_NOWAIT; if (ctx->flags & IORING_SETUP_IOPOLL) { @@ -838,7 +848,7 @@ static int __io_read(struct io_kiocb *req, unsigned int issue_flags) if (force_nonblock) { /* If the file doesn't support async, just async punt */ - if (unlikely(!io_file_supports_nowait(req))) + if (unlikely(!io_file_supports_nowait(req, EPOLLIN))) return -EAGAIN; kiocb->ki_flags |= IOCB_NOWAIT; } else { @@ -952,13 +962,6 @@ int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags) ret = __io_read(req, issue_flags); /* - * If the file doesn't support proper NOWAIT, then disable multishot - * and stay in single shot mode. - */ - if (!io_file_supports_nowait(req)) - req->flags &= ~REQ_F_APOLL_MULTISHOT; - - /* * If we get -EAGAIN, recycle our buffer and just let normal poll * handling arm it. */ @@ -972,14 +975,15 @@ int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags) if (issue_flags & IO_URING_F_MULTISHOT) return IOU_ISSUE_SKIP_COMPLETE; return -EAGAIN; - } - - /* - * Any successful return value will keep the multishot read armed. - */ - if (ret > 0 && req->flags & REQ_F_APOLL_MULTISHOT) { + } else if (ret <= 0) { + io_kbuf_recycle(req, issue_flags); + if (ret < 0) + req_set_fail(req); + } else { /* - * Put our buffer and post a CQE. If we fail to post a CQE, then + * Any successful return value will keep the multishot read + * armed, if it's still set. Put our buffer and post a CQE. If + * we fail to post a CQE, or multishot is no longer set, then * jump to the termination path. This request is then done. */ cflags = io_put_kbuf(req, ret, issue_flags); @@ -1010,6 +1014,25 @@ int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags) return IOU_OK; } +static bool io_kiocb_start_write(struct io_kiocb *req, struct kiocb *kiocb) +{ + struct inode *inode; + bool ret; + + if (!(req->flags & REQ_F_ISREG)) + return true; + if (!(kiocb->ki_flags & IOCB_NOWAIT)) { + kiocb_start_write(kiocb); + return true; + } + + inode = file_inode(kiocb->ki_filp); + ret = sb_start_write_trylock(inode->i_sb); + if (ret) + __sb_writers_release(inode->i_sb, SB_FREEZE_WRITE); + return ret; +} + int io_write(struct io_kiocb *req, unsigned int issue_flags) { bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; @@ -1026,7 +1049,7 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags) if (force_nonblock) { /* If the file doesn't support async, just async punt */ - if (unlikely(!io_file_supports_nowait(req))) + if (unlikely(!io_file_supports_nowait(req, EPOLLOUT))) goto ret_eagain; /* Check if we can support NOWAIT. */ @@ -1047,8 +1070,8 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags) if (unlikely(ret)) return ret; - if (req->flags & REQ_F_ISREG) - kiocb_start_write(kiocb); + if (unlikely(!io_kiocb_start_write(req, kiocb))) + return -EAGAIN; kiocb->ki_flags |= IOCB_WRITE; if (likely(req->file->f_op->write_iter)) |