diff --git a/include/linux/fs.h b/include/linux/fs.h index afbd97e44f0bb93d8acfd3a6a6881fcd75951567..4ce9c03d40cd67993f7a1d522735110938757db4 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1762,6 +1762,41 @@ static inline bool sb_start_intwrite_trylock(struct super_block *sb) return __sb_start_write_trylock(sb, SB_FREEZE_FS); } +/** + * kiocb_start_write - get write access to a superblock for async file io + * @iocb: the io context we want to submit the write with + * + * This is a variant of sb_start_write() for async io submission. + * Should be matched with a call to kiocb_end_write(). + */ +static inline void kiocb_start_write(struct kiocb *iocb) +{ + struct inode *inode = file_inode(iocb->ki_filp); + + sb_start_write(inode->i_sb); + /* + * Fool lockdep by telling it the lock got released so that it + * doesn't complain about the held lock when we return to userspace. + */ + __sb_writers_release(inode->i_sb, SB_FREEZE_WRITE); +} + +/** + * kiocb_end_write - drop write access to a superblock after async file io + * @iocb: the io context we sumbitted the write with + * + * Should be matched with a call to kiocb_start_write(). + */ +static inline void kiocb_end_write(struct kiocb *iocb) +{ + struct inode *inode = file_inode(iocb->ki_filp); + + /* + * Tell lockdep we inherited freeze protection from submission thread. + */ + __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); + sb_end_write(inode->i_sb); +} extern bool inode_owner_or_capable(const struct inode *inode); diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index efcaf9e74c83da1ddb8a7a4d5d740502fb20eef7..4d69fb4cf80364c9f3bbb820bd39432db4af3c20 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2650,17 +2650,12 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min) return ret; } -static void kiocb_end_write(struct io_kiocb *req) +static void io_req_end_write(struct io_kiocb *req) { - /* - * Tell lockdep we inherited freeze protection from submission - * thread. - */ if (req->flags & REQ_F_ISREG) { - struct super_block *sb = file_inode(req->file)->i_sb; + struct io_rw *rw = &req->rw; - __sb_writers_acquired(sb, SB_FREEZE_WRITE); - sb_end_write(sb); + kiocb_end_write(&rw->kiocb); } } @@ -2714,7 +2709,7 @@ static bool io_rw_should_reissue(struct io_kiocb *req) static bool __io_complete_rw_common(struct io_kiocb *req, long res) { if (req->rw.kiocb.ki_flags & IOCB_WRITE) { - kiocb_end_write(req); + io_req_end_write(req); fsnotify_modify(req->file); } else { fsnotify_access(req->file); @@ -2787,7 +2782,7 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); if (kiocb->ki_flags & IOCB_WRITE) - kiocb_end_write(req); + io_req_end_write(req); if (unlikely(res != req->result)) { if (res == -EAGAIN && io_rw_should_reissue(req)) { req->flags |= REQ_F_REISSUE; @@ -3666,6 +3661,25 @@ static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return io_prep_rw(req, sqe, WRITE); } +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; +} + static int io_write(struct io_kiocb *req, unsigned int issue_flags) { struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; @@ -3709,18 +3723,8 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags) if (unlikely(ret)) goto out_free; - /* - * Open-code file_start_write here to grab freeze protection, - * which will be released by another thread in - * io_complete_rw(). Fool lockdep by telling it the lock got - * released so that it doesn't complain about the held lock when - * we return to userspace. - */ - if (req->flags & REQ_F_ISREG) { - sb_start_write(file_inode(req->file)->i_sb); - __sb_writers_release(file_inode(req->file)->i_sb, - SB_FREEZE_WRITE); - } + if (unlikely(!io_kiocb_start_write(req, kiocb))) + goto copy_iov; kiocb->ki_flags |= IOCB_WRITE; if (req->file->f_op->write_iter) @@ -3756,7 +3760,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags) ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false); if (!ret) { if (kiocb->ki_flags & IOCB_WRITE) - kiocb_end_write(req); + io_req_end_write(req); return -EAGAIN; } return ret;