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From: Douglas Gilbert <dgilbert@interlog.com>
To: linux-scsi@vger.kernel.org
Cc: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com, hare@suse.de
Subject: [PATCH v6 16/37] sg: rework sg_mmap
Date: Mon, 13 Jan 2020 00:57:34 +0100	[thread overview]
Message-ID: <20200112235755.14197-17-dgilbert@interlog.com> (raw)
In-Reply-To: <20200112235755.14197-1-dgilbert@interlog.com>

Simple rework of the sg_mmap() function.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
 drivers/scsi/sg.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index d4a1ca180d21..01c4c1f09c8d 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1483,14 +1483,15 @@ static const struct vm_operations_struct sg_mmap_vm_ops = {
 	.fault = sg_vma_fault,
 };
 
+/* Entry point for mmap(2) system call */
 static int
 sg_mmap(struct file *filp, struct vm_area_struct *vma)
 {
-	struct sg_fd *sfp;
-	unsigned long req_sz, len, sa;
-	struct sg_scatter_hold *rsv_schp;
 	int k, length;
 	int ret = 0;
+	unsigned long req_sz, len, sa;
+	struct sg_scatter_hold *rsv_schp;
+	struct sg_fd *sfp;
 
 	if (!filp || !vma)
 		return -ENXIO;
@@ -1503,19 +1504,23 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
 	SG_LOG(3, sfp, "%s: vm_start=%p, len=%d\n", __func__,
 	       (void *)vma->vm_start, (int)req_sz);
 	if (vma->vm_pgoff)
-		return -EINVAL;	/* want no offset */
-	rsv_schp = &sfp->reserve;
+		return -EINVAL; /* only an offset of 0 accepted */
+	/* Check reserve request is inactive and has large enough buffer */
 	mutex_lock(&sfp->f_mutex);
-	if (req_sz > rsv_schp->buflen) {
-		ret = -ENOMEM;	/* cannot map more than reserved buffer */
+	if (sfp->res_in_use) {
+		ret = -EBUSY;
+		goto out;
+	}
+	rsv_schp = &sfp->reserve;
+	if (req_sz > (unsigned long)rsv_schp->buflen) {
+		ret = -ENOMEM;
 		goto out;
 	}
-
 	sa = vma->vm_start;
 	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
-	for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; k++) {
+	for (k = 0; k < rsv_schp->num_sgat && sa < vma->vm_end; ++k) {
 		len = vma->vm_end - sa;
-		len = (len < length) ? len : length;
+		len = min_t(unsigned long, len, (unsigned long)length);
 		sa += len;
 	}
 
-- 
2.24.1


  parent reply	other threads:[~2020-01-12 23:58 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-12 23:57 [PATCH v6 00/37] sg: add v4 interface Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 01/37] sg: move functions around Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 02/37] sg: remove typedefs, type+formatting cleanup Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 03/37] sg: sg_log and is_enabled Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 04/37] sg: rework sg_poll(), minor changes Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 05/37] sg: bitops in sg_device Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 06/37] sg: make open count an atomic Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 07/37] sg: move header to uapi section Douglas Gilbert
2020-01-13  5:34   ` kbuild test robot
2020-01-14  9:16     ` Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 08/37] sg: speed sg_poll and sg_get_num_waiting Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 09/37] sg: sg_allow_if_err_recovery and renames Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 10/37] sg: improve naming Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 11/37] sg: change rwlock to spinlock Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 12/37] sg: ioctl handling Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 13/37] sg: split sg_read Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 14/37] sg: sg_common_write add structure for arguments Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 15/37] sg: rework sg_vma_fault Douglas Gilbert
2020-01-12 23:57 ` Douglas Gilbert [this message]
2020-01-12 23:57 ` [PATCH v6 17/37] sg: replace sg_allow_access Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 18/37] sg: rework scatter gather handling Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 19/37] sg: introduce request state machine Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 20/37] sg: sg_find_srp_by_id Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 21/37] sg: sg_fill_request_element Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 22/37] sg: printk change %p to %pK Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 23/37] sg: xarray for fds in device Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 24/37] sg: xarray for reqs in fd Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 25/37] sg: replace rq array with lists Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 26/37] sg: sense buffer rework Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 27/37] sg: add sg v4 interface support Douglas Gilbert
2020-01-13  8:28   ` kbuild test robot
2020-01-14 10:21     ` Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 28/37] sg: rework debug info Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 29/37] sg: add 8 byte SCSI LUN to sg_scsi_id Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 30/37] sg: expand sg_comm_wr_t Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 31/37] sg: add sg_iosubmit_v3 and sg_ioreceive_v3 ioctls Douglas Gilbert
2020-01-13  0:50   ` Bart Van Assche
2020-01-13 10:39     ` Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 32/37] sg: add some __must_hold macros Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 33/37] sg: move procfs objects to avoid forward decls Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 34/37] sg: protect multiple receivers Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 35/37] sg: first debugfs support Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 36/37] sg: warn v3 write system call users Douglas Gilbert
2020-01-12 23:57 ` [PATCH v6 37/37] sg: bump version to 4.0.08 Douglas Gilbert

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