From patchwork Mon Oct 24 03:20:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Gilbert X-Patchwork-Id: 618691 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E72FBC433FE for ; Mon, 24 Oct 2022 03:25:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230270AbiJXDZp (ORCPT ); Sun, 23 Oct 2022 23:25:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230118AbiJXDXD (ORCPT ); Sun, 23 Oct 2022 23:23:03 -0400 Received: from smtp.infotech.no (smtp.infotech.no [82.134.31.41]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C87BB6E2EC for ; Sun, 23 Oct 2022 20:21:56 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by smtp.infotech.no (Postfix) with ESMTP id 9A7D42041C0; Mon, 24 Oct 2022 05:21:56 +0200 (CEST) X-Virus-Scanned: by amavisd-new-2.6.6 (20110518) (Debian) at infotech.no Received: from smtp.infotech.no ([127.0.0.1]) by localhost (smtp.infotech.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id p9Zv5hqK1Q9n; Mon, 24 Oct 2022 05:21:56 +0200 (CEST) Received: from treten.bingwo.ca (unknown [10.16.20.11]) by smtp.infotech.no (Postfix) with ESMTPA id 70BF42041AF; Mon, 24 Oct 2022 05:21:55 +0200 (CEST) From: Douglas Gilbert To: linux-scsi@vger.kernel.org Cc: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com, hare@suse.de, bvanassche@acm.org Subject: [PATCH v25 37/44] sg: add mmap_sz tracking Date: Sun, 23 Oct 2022 23:20:51 -0400 Message-Id: <20221024032058.14077-38-dgilbert@interlog.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221024032058.14077-1-dgilbert@interlog.com> References: <20221024032058.14077-1-dgilbert@interlog.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Track mmap_sz from prior mmap(2) call, per sg file descriptor. Also reset this value whenever munmap(2) is called. Fail SG_FLAG_MMAP_IO uses if mmap(2) hasn't been called or the memory associated with it is not large enough for the current request. Remove SG_FFD_MMAP_CALLED bit as it can be deduced from sfp->mmap_sz where a value of 0 implies no mmap() call active. Reviewed-by: Hannes Reinecke Signed-off-by: Douglas Gilbert --- drivers/scsi/sg.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index c9eb9e842f9e..a37e1156e4c2 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -124,8 +124,7 @@ enum sg_rq_state { /* N.B. sg_rq_state_arr assumes SG_RS_AWAIT_RCV==2 */ #define SG_FFD_FORCE_PACKID 0 /* receive only given pack_id/tag */ #define SG_FFD_CMD_Q 1 /* clear: only 1 active req per fd */ #define SG_FFD_KEEP_ORPHAN 2 /* policy for this fd */ -#define SG_FFD_MMAP_CALLED 3 /* mmap(2) system call made on fd */ -#define SG_FFD_Q_AT_TAIL 5 /* set: queue reqs at tail of blk q */ +#define SG_FFD_Q_AT_TAIL 3 /* set: queue reqs at tail of blk q */ /* Bit positions (flags) for sg_device::fdev_bm bitmask follow */ #define SG_FDEV_EXCLUDE 0 /* have fd open with O_EXCL */ @@ -234,6 +233,7 @@ struct sg_fd { /* holds the state of a file descriptor */ atomic_t waiting; /* number of requests awaiting receive */ atomic_t req_cnt; /* number of requests */ int sgat_elem_sz; /* initialized to scatter_elem_sz */ + int mmap_sz; /* byte size of previous mmap() call */ unsigned long ffd_bm[1]; /* see SG_FFD_* defines above */ pid_t tid; /* thread id when opened */ u8 next_cmd_len; /* 0: automatic, >0: use on next write() */ @@ -724,10 +724,14 @@ sg_write(struct file *filp, const char __user *p, size_t count, loff_t *ppos) static inline int sg_chk_mmap(struct sg_fd *sfp, int rq_flags, int len) { + if (unlikely(sfp->mmap_sz == 0)) + return -EBADFD; if (atomic_read(&sfp->submitted) > 0) return -EBUSY; /* already active requests on fd */ if (len > sfp->rsv_srp->sgat_h.buflen) return -ENOMEM; /* MMAP_IO size must fit in reserve */ + if (unlikely(len > sfp->mmap_sz)) + return -ENOMEM; /* MMAP_IO size can't exceed mmap() size */ if (rq_flags & SG_FLAG_DIRECT_IO) return -EINVAL; /* not both MMAP_IO and DIRECT_IO */ return 0; @@ -1751,13 +1755,12 @@ sg_set_reserved_sz(struct sg_fd *sfp, int want_rsv_sz) int new_sz, blen, res; unsigned long iflags; struct sg_scatter_hold n_schp, o_schp; - struct sg_request *srp; + struct sg_request *srp = sfp->rsv_srp; struct xarray *xafp = &sfp->srp_arr; - srp = sfp->rsv_srp; if (!srp) return -EPROTO; - if (test_bit(SG_FRQ_FOR_MMAP, srp->frq_bm)) + if (SG_RS_ACTIVE(srp) || sfp->mmap_sz > 0) return -EBUSY; new_sz = min_t(int, want_rsv_sz, sfp->parentdp->max_sgat_sz); new_sz = max_t(int, new_sz, sfp->sgat_elem_sz); @@ -2171,6 +2174,7 @@ sg_vma_close(struct vm_area_struct *vma) pr_warn("%s: sfp null\n", __func__); return; } + sfp->mmap_sz = 0; kref_put(&sfp->f_ref, sg_remove_sfp); /* get in: sg_vma_open() */ } @@ -2261,7 +2265,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma) req_sz = vma->vm_end - vma->vm_start; SG_LOG(3, sfp, "%s: vm_start=%pK, len=%d\n", __func__, (void *)vma->vm_start, (int)req_sz); - if (vma->vm_pgoff) { + if (unlikely(vma->vm_pgoff || req_sz < SG_DEF_SECTOR_SZ)) { res = -EINVAL; /* only an offset of 0 accepted */ goto fini; } @@ -2275,7 +2279,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma) res = -ENOMEM; goto fini; } - if (test_and_set_bit(SG_FFD_MMAP_CALLED, sfp->ffd_bm)) { + if (sfp->mmap_sz > 0) { SG_LOG(1, sfp, "%s: multiple invocations on this fd\n", __func__); res = -EADDRINUSE; @@ -2292,6 +2296,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma) goto fini; } } + sfp->mmap_sz = req_sz; vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP; vma->vm_private_data = sfp; vma->vm_ops = &sg_mmap_vm_ops; @@ -3924,8 +3929,7 @@ sg_proc_debug_fd(struct sg_fd *fp, char *obp, int len, unsigned long idx) (int)test_bit(SG_FFD_FORCE_PACKID, fp->ffd_bm), (int)test_bit(SG_FFD_KEEP_ORPHAN, fp->ffd_bm), fp->ffd_bm[0]); - n += scnprintf(obp + n, len - n, " mmap_called=%d\n", - test_bit(SG_FFD_MMAP_CALLED, fp->ffd_bm)); + n += scnprintf(obp + n, len - n, " mmap_sz=%d\n", fp->mmap_sz); n += scnprintf(obp + n, len - n, " submitted=%d waiting=%d open thr_id=%d\n", atomic_read(&fp->submitted),