From 9c53a1792a5e6c708897d0cb17f2a4509e499a52 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:40 +0100 Subject: xen: introduce xenbus_read_unsigned() There are multiple instances of code reading an optional unsigned parameter from Xenstore via xenbus_scanf(). Instead of repeating the same code over and over add a service function doing the job. Signed-off-by: Juergen Gross Reviewed-by: David Vrabel --- drivers/xen/xenbus/xenbus_xs.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers') diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index 22f7cd711c57..99dfdfae42c6 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -559,6 +559,21 @@ int xenbus_scanf(struct xenbus_transaction t, } EXPORT_SYMBOL_GPL(xenbus_scanf); +/* Read an (optional) unsigned value. */ +unsigned int xenbus_read_unsigned(const char *dir, const char *node, + unsigned int default_val) +{ + unsigned int val; + int ret; + + ret = xenbus_scanf(XBT_NIL, dir, node, "%u", &val); + if (ret <= 0) + val = default_val; + + return val; +} +EXPORT_SYMBOL_GPL(xenbus_read_unsigned); + /* Single printf and write: returns -errno or 0. */ int xenbus_printf(struct xenbus_transaction t, const char *dir, const char *node, const char *fmt, ...) -- cgit v1.2.3-58-ga151 From 8235777b2068e3280b6fa1413f1940ade31f0adf Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:40 +0100 Subject: xen: make use of xenbus_read_unsigned() in xen-blkback Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of one read from int to unsigned, but this case has been wrong before: negative values are not allowed for the modified case. Cc: konrad.wilk@oracle.com Cc: roger.pau@citrix.com Signed-off-by: Juergen Gross Acked-by: David Vrabel --- drivers/block/xen-blkback/xenbus.c | 36 ++++++++++++++---------------------- 1 file changed, 14 insertions(+), 22 deletions(-) (limited to 'drivers') diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 3cc6d1d86f1e..415e79b69d34 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -533,13 +533,11 @@ static void xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info struct xenbus_device *dev = be->dev; struct xen_blkif *blkif = be->blkif; int err; - int state = 0, discard_enable; + int state = 0; struct block_device *bdev = be->blkif->vbd.bdev; struct request_queue *q = bdev_get_queue(bdev); - err = xenbus_scanf(XBT_NIL, dev->nodename, "discard-enable", "%d", - &discard_enable); - if (err == 1 && !discard_enable) + if (!xenbus_read_unsigned(dev->nodename, "discard-enable", 1)) return; if (blk_queue_discard(q)) { @@ -1039,30 +1037,24 @@ static int connect_ring(struct backend_info *be) xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol); return -ENOSYS; } - err = xenbus_scanf(XBT_NIL, dev->otherend, - "feature-persistent", "%u", &pers_grants); - if (err <= 0) - pers_grants = 0; - + pers_grants = xenbus_read_unsigned(dev->otherend, "feature-persistent", + 0); be->blkif->vbd.feature_gnt_persistent = pers_grants; be->blkif->vbd.overflow_max_grants = 0; /* * Read the number of hardware queues from frontend. */ - err = xenbus_scanf(XBT_NIL, dev->otherend, "multi-queue-num-queues", - "%u", &requested_num_queues); - if (err < 0) { - requested_num_queues = 1; - } else { - if (requested_num_queues > xenblk_max_queues - || requested_num_queues == 0) { - /* Buggy or malicious guest. */ - xenbus_dev_fatal(dev, err, - "guest requested %u queues, exceeding the maximum of %u.", - requested_num_queues, xenblk_max_queues); - return -ENOSYS; - } + requested_num_queues = xenbus_read_unsigned(dev->otherend, + "multi-queue-num-queues", + 1); + if (requested_num_queues > xenblk_max_queues + || requested_num_queues == 0) { + /* Buggy or malicious guest. */ + xenbus_dev_fatal(dev, err, + "guest requested %u queues, exceeding the maximum of %u.", + requested_num_queues, xenblk_max_queues); + return -ENOSYS; } be->blkif->nr_rings = requested_num_queues; if (xen_blkif_alloc_rings(be->blkif)) -- cgit v1.2.3-58-ga151 From f27dc1ac56865c2cc43d0ec3110a2b4a95b04e1d Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:40 +0100 Subject: xen: make use of xenbus_read_unsigned() in xen-blkfront Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of some reads from int to unsigned, but these cases have been wrong before: negative values are not allowed for the modified cases. Cc: konrad.wilk@oracle.com Cc: roger.pau@citrix.com Signed-off-by: Juergen Gross Acked-by: David Vrabel --- drivers/block/xen-blkfront.c | 81 ++++++++++++++------------------------------ 1 file changed, 26 insertions(+), 55 deletions(-) (limited to 'drivers') diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 9908597c5209..2ee9646d8a5f 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1758,17 +1758,13 @@ static int talk_to_blkback(struct xenbus_device *dev, const char *message = NULL; struct xenbus_transaction xbt; int err; - unsigned int i, max_page_order = 0; - unsigned int ring_page_order = 0; + unsigned int i, max_page_order; + unsigned int ring_page_order; - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "max-ring-page-order", "%u", &max_page_order); - if (err != 1) - info->nr_ring_pages = 1; - else { - ring_page_order = min(xen_blkif_max_ring_order, max_page_order); - info->nr_ring_pages = 1 << ring_page_order; - } + max_page_order = xenbus_read_unsigned(info->xbdev->otherend, + "max-ring-page-order", 0); + ring_page_order = min(xen_blkif_max_ring_order, max_page_order); + info->nr_ring_pages = 1 << ring_page_order; for (i = 0; i < info->nr_rings; i++) { struct blkfront_ring_info *rinfo = &info->rinfo[i]; @@ -1877,18 +1873,14 @@ again: static int negotiate_mq(struct blkfront_info *info) { - unsigned int backend_max_queues = 0; - int err; + unsigned int backend_max_queues; unsigned int i; BUG_ON(info->nr_rings); /* Check if backend supports multiple queues. */ - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "multi-queue-max-queues", "%u", &backend_max_queues); - if (err < 0) - backend_max_queues = 1; - + backend_max_queues = xenbus_read_unsigned(info->xbdev->otherend, + "multi-queue-max-queues", 1); info->nr_rings = min(backend_max_queues, xen_blkif_max_queues); /* We need at least one ring. */ if (!info->nr_rings) @@ -2195,7 +2187,6 @@ static void blkfront_setup_discard(struct blkfront_info *info) int err; unsigned int discard_granularity; unsigned int discard_alignment; - unsigned int discard_secure; info->feature_discard = 1; err = xenbus_gather(XBT_NIL, info->xbdev->otherend, @@ -2206,10 +2197,9 @@ static void blkfront_setup_discard(struct blkfront_info *info) info->discard_granularity = discard_granularity; info->discard_alignment = discard_alignment; } - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "discard-secure", "%u", &discard_secure); - if (err > 0) - info->feature_secdiscard = !!discard_secure; + info->feature_secdiscard = + !!xenbus_read_unsigned(info->xbdev->otherend, "discard-secure", + 0); } static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo) @@ -2301,16 +2291,11 @@ out_of_memory: */ static void blkfront_gather_backend_features(struct blkfront_info *info) { - int err; - int barrier, flush, discard, persistent; unsigned int indirect_segments; info->feature_flush = 0; info->feature_fua = 0; - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "feature-barrier", "%d", &barrier); - /* * If there's no "feature-barrier" defined, then it means * we're dealing with a very old backend which writes @@ -2318,7 +2303,7 @@ static void blkfront_gather_backend_features(struct blkfront_info *info) * * If there are barriers, then we use flush. */ - if (err > 0 && barrier) { + if (xenbus_read_unsigned(info->xbdev->otherend, "feature-barrier", 0)) { info->feature_flush = 1; info->feature_fua = 1; } @@ -2327,35 +2312,23 @@ static void blkfront_gather_backend_features(struct blkfront_info *info) * And if there is "feature-flush-cache" use that above * barriers. */ - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "feature-flush-cache", "%d", &flush); - - if (err > 0 && flush) { + if (xenbus_read_unsigned(info->xbdev->otherend, "feature-flush-cache", + 0)) { info->feature_flush = 1; info->feature_fua = 0; } - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "feature-discard", "%d", &discard); - - if (err > 0 && discard) + if (xenbus_read_unsigned(info->xbdev->otherend, "feature-discard", 0)) blkfront_setup_discard(info); - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "feature-persistent", "%d", &persistent); - if (err <= 0) - info->feature_persistent = 0; - else - info->feature_persistent = persistent; + info->feature_persistent = + xenbus_read_unsigned(info->xbdev->otherend, + "feature-persistent", 0); - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "feature-max-indirect-segments", "%u", - &indirect_segments); - if (err <= 0) - info->max_indirect_segments = 0; - else - info->max_indirect_segments = min(indirect_segments, - xen_blkif_max_segments); + indirect_segments = xenbus_read_unsigned(info->xbdev->otherend, + "feature-max-indirect-segments", 0); + info->max_indirect_segments = min(indirect_segments, + xen_blkif_max_segments); } /* @@ -2420,11 +2393,9 @@ static void blkfront_connect(struct blkfront_info *info) * provide this. Assume physical sector size to be the same as * sector_size in that case. */ - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "physical-sector-size", "%u", &physical_sector_size); - if (err != 1) - physical_sector_size = sector_size; - + physical_sector_size = xenbus_read_unsigned(info->xbdev->otherend, + "physical-sector-size", + sector_size); blkfront_gather_backend_features(info); for (i = 0; i < info->nr_rings; i++) { err = blkfront_setup_indirect(&info->rinfo[i]); -- cgit v1.2.3-58-ga151 From 0240933469ea4cc1aa1c32867349c4aa718fe264 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:40 +0100 Subject: xen: make use of xenbus_read_unsigned() in xen-tpmfront Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of one read from int to unsigned, but this case has been wrong before: negative values are not allowed for the modified case. Cc: peterhuewe@gmx.de Cc: tpmdd@selhorst.net Cc: jarkko.sakkinen@linux.intel.com Cc: jgunthorpe@obsidianresearch.com Cc: tpmdd-devel@lists.sourceforge.net Signed-off-by: Juergen Gross Reviewed-by: Jarkko Sakkinen Acked-by: David Vrabel --- drivers/char/tpm/xen-tpmfront.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'drivers') diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c index 62028f483bba..50072cc4fe5c 100644 --- a/drivers/char/tpm/xen-tpmfront.c +++ b/drivers/char/tpm/xen-tpmfront.c @@ -337,18 +337,14 @@ static int tpmfront_resume(struct xenbus_device *dev) static void backend_changed(struct xenbus_device *dev, enum xenbus_state backend_state) { - int val; - switch (backend_state) { case XenbusStateInitialised: case XenbusStateConnected: if (dev->state == XenbusStateConnected) break; - if (xenbus_scanf(XBT_NIL, dev->otherend, - "feature-protocol-v2", "%d", &val) < 0) - val = 0; - if (!val) { + if (!xenbus_read_unsigned(dev->otherend, "feature-protocol-v2", + 0)) { xenbus_dev_fatal(dev, -EINVAL, "vTPM protocol 2 required"); return; -- cgit v1.2.3-58-ga151 From 81362c6f159dcb59fadd60927aa00497d715ca80 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:40 +0100 Subject: xen: make use of xenbus_read_unsigned() in xen-kbdfront Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of the reads from int to unsigned, but these cases have been wrong before: negative values are not allowed for the modified cases. Cc: dmitry.torokhov@gmail.com Cc: linux-input@vger.kernel.org Signed-off-by: Juergen Gross Acked-by: David Vrabel --- drivers/input/misc/xen-kbdfront.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'drivers') diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c index 227fbd2dbb71..3900875dec10 100644 --- a/drivers/input/misc/xen-kbdfront.c +++ b/drivers/input/misc/xen-kbdfront.c @@ -108,7 +108,8 @@ static irqreturn_t input_handler(int rq, void *dev_id) static int xenkbd_probe(struct xenbus_device *dev, const struct xenbus_device_id *id) { - int ret, i, abs; + int ret, i; + unsigned int abs; struct xenkbd_info *info; struct input_dev *kbd, *ptr; @@ -127,8 +128,7 @@ static int xenkbd_probe(struct xenbus_device *dev, if (!info->page) goto error_nomem; - if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0) - abs = 0; + abs = xenbus_read_unsigned(dev->otherend, "feature-abs-pointer", 0); if (abs) { ret = xenbus_write(XBT_NIL, dev->nodename, "request-abs-pointer", "1"); @@ -322,11 +322,8 @@ static void xenkbd_backend_changed(struct xenbus_device *dev, case XenbusStateInitWait: InitWait: - ret = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "feature-abs-pointer", "%d", &val); - if (ret < 0) - val = 0; - if (val) { + if (xenbus_read_unsigned(info->xbdev->otherend, + "feature-abs-pointer", 0)) { ret = xenbus_write(XBT_NIL, info->xbdev->nodename, "request-abs-pointer", "1"); if (ret) -- cgit v1.2.3-58-ga151 From f95842e7a9f235ef3b7d6d4b70fee2244149f1e7 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:41 +0100 Subject: xen: make use of xenbus_read_unsigned() in xen-netback Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of some reads from int to unsigned, but these cases have been wrong before: negative values are not allowed for the modified cases. Cc: wei.liu2@citrix.com Cc: paul.durrant@citrix.com Cc: netdev@vger.kernel.org Signed-off-by: Juergen Gross Reviewed-by: Paul Durrant Acked-by: David Vrabel --- drivers/net/xen-netback/xenbus.c | 50 +++++++++++----------------------------- 1 file changed, 14 insertions(+), 36 deletions(-) (limited to 'drivers') diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 8674e188b697..7356e00fac54 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -785,12 +785,9 @@ static void xen_mcast_ctrl_changed(struct xenbus_watch *watch, struct xenvif *vif = container_of(watch, struct xenvif, mcast_ctrl_watch); struct xenbus_device *dev = xenvif_to_xenbus_device(vif); - int val; - if (xenbus_scanf(XBT_NIL, dev->otherend, - "request-multicast-control", "%d", &val) < 0) - val = 0; - vif->multicast_control = !!val; + vif->multicast_control = !!xenbus_read_unsigned(dev->otherend, + "request-multicast-control", 0); } static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev, @@ -934,12 +931,9 @@ static void connect(struct backend_info *be) /* Check whether the frontend requested multiple queues * and read the number requested. */ - err = xenbus_scanf(XBT_NIL, dev->otherend, - "multi-queue-num-queues", - "%u", &requested_num_queues); - if (err < 0) { - requested_num_queues = 1; /* Fall back to single queue */ - } else if (requested_num_queues > xenvif_max_queues) { + requested_num_queues = xenbus_read_unsigned(dev->otherend, + "multi-queue-num-queues", 1); + if (requested_num_queues > xenvif_max_queues) { /* buggy or malicious guest */ xenbus_dev_fatal(dev, err, "guest requested %u queues, exceeding the maximum of %u.", @@ -1134,7 +1128,7 @@ static int read_xenbus_vif_flags(struct backend_info *be) struct xenvif *vif = be->vif; struct xenbus_device *dev = be->dev; unsigned int rx_copy; - int err, val; + int err; err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u", &rx_copy); @@ -1150,10 +1144,7 @@ static int read_xenbus_vif_flags(struct backend_info *be) if (!rx_copy) return -EOPNOTSUPP; - if (xenbus_scanf(XBT_NIL, dev->otherend, - "feature-rx-notify", "%d", &val) < 0) - val = 0; - if (!val) { + if (!xenbus_read_unsigned(dev->otherend, "feature-rx-notify", 0)) { /* - Reduce drain timeout to poll more frequently for * Rx requests. * - Disable Rx stall detection. @@ -1162,34 +1153,21 @@ static int read_xenbus_vif_flags(struct backend_info *be) be->vif->stall_timeout = 0; } - if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg", - "%d", &val) < 0) - val = 0; - vif->can_sg = !!val; + vif->can_sg = !!xenbus_read_unsigned(dev->otherend, "feature-sg", 0); vif->gso_mask = 0; - if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4", - "%d", &val) < 0) - val = 0; - if (val) + if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv4", 0)) vif->gso_mask |= GSO_BIT(TCPV4); - if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6", - "%d", &val) < 0) - val = 0; - if (val) + if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv6", 0)) vif->gso_mask |= GSO_BIT(TCPV6); - if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload", - "%d", &val) < 0) - val = 0; - vif->ip_csum = !val; + vif->ip_csum = !xenbus_read_unsigned(dev->otherend, + "feature-no-csum-offload", 0); - if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-ipv6-csum-offload", - "%d", &val) < 0) - val = 0; - vif->ipv6_csum = !!val; + vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend, + "feature-ipv6-csum-offload", 0); return 0; } -- cgit v1.2.3-58-ga151 From 2890ea5c13321d26732c4520649681965480ee1c Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:41 +0100 Subject: xen: make use of xenbus_read_unsigned() in xen-netfront Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of some reads from int to unsigned, but these cases have been wrong before: negative values are not allowed for the modified cases. Cc: netdev@vger.kernel.org Signed-off-by: Juergen Gross Acked-by: David Vrabel --- drivers/net/xen-netfront.c | 67 +++++++++++++--------------------------------- 1 file changed, 18 insertions(+), 49 deletions(-) (limited to 'drivers') diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index e17879dd5d5a..95d664e3d09c 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1169,43 +1169,23 @@ static netdev_features_t xennet_fix_features(struct net_device *dev, netdev_features_t features) { struct netfront_info *np = netdev_priv(dev); - int val; - if (features & NETIF_F_SG) { - if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", - "%d", &val) < 0) - val = 0; + if (features & NETIF_F_SG && + !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0)) + features &= ~NETIF_F_SG; - if (!val) - features &= ~NETIF_F_SG; - } - - if (features & NETIF_F_IPV6_CSUM) { - if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, - "feature-ipv6-csum-offload", "%d", &val) < 0) - val = 0; - - if (!val) - features &= ~NETIF_F_IPV6_CSUM; - } - - if (features & NETIF_F_TSO) { - if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, - "feature-gso-tcpv4", "%d", &val) < 0) - val = 0; + if (features & NETIF_F_IPV6_CSUM && + !xenbus_read_unsigned(np->xbdev->otherend, + "feature-ipv6-csum-offload", 0)) + features &= ~NETIF_F_IPV6_CSUM; - if (!val) - features &= ~NETIF_F_TSO; - } + if (features & NETIF_F_TSO && + !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0)) + features &= ~NETIF_F_TSO; - if (features & NETIF_F_TSO6) { - if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, - "feature-gso-tcpv6", "%d", &val) < 0) - val = 0; - - if (!val) - features &= ~NETIF_F_TSO6; - } + if (features & NETIF_F_TSO6 && + !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0)) + features &= ~NETIF_F_TSO6; return features; } @@ -1821,18 +1801,13 @@ static int talk_to_netback(struct xenbus_device *dev, info->netdev->irq = 0; /* Check if backend supports multiple queues */ - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "multi-queue-max-queues", "%u", &max_queues); - if (err < 0) - max_queues = 1; + max_queues = xenbus_read_unsigned(info->xbdev->otherend, + "multi-queue-max-queues", 1); num_queues = min(max_queues, xennet_max_queues); /* Check feature-split-event-channels */ - err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "feature-split-event-channels", "%u", - &feature_split_evtchn); - if (err < 0) - feature_split_evtchn = 0; + feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend, + "feature-split-event-channels", 0); /* Read mac addr. */ err = xen_net_read_mac(dev, info->netdev->dev_addr); @@ -1966,16 +1941,10 @@ static int xennet_connect(struct net_device *dev) struct netfront_info *np = netdev_priv(dev); unsigned int num_queues = 0; int err; - unsigned int feature_rx_copy; unsigned int j = 0; struct netfront_queue *queue = NULL; - err = xenbus_scanf(XBT_NIL, np->xbdev->otherend, - "feature-rx-copy", "%u", &feature_rx_copy); - if (err != 1) - feature_rx_copy = 0; - - if (!feature_rx_copy) { + if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) { dev_info(&dev->dev, "backend does not support copying receive path\n"); return -ENODEV; -- cgit v1.2.3-58-ga151 From 58faf07b76817782ea20c392639569ea613cd439 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:41 +0100 Subject: xen: make use of xenbus_read_unsigned() in xen-pcifront Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of the read from int to unsigned, but this case has been wrong before: negative values are not allowed for the modified case. Cc: bhelgaas@google.com Cc: linux-pci@vger.kernel.org Signed-off-by: Juergen Gross Acked-by: Bjorn Helgaas Acked-by: David Vrabel --- drivers/pci/xen-pcifront.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'drivers') diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c index d6ff5e82377d..8fc2e9532575 100644 --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -1038,10 +1038,8 @@ static int pcifront_detach_devices(struct pcifront_device *pdev) err = -ENOMEM; goto out; } - err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, "%d", - &state); - if (err != 1) - state = XenbusStateUnknown; + state = xenbus_read_unsigned(pdev->xdev->otherend, str, + XenbusStateUnknown); if (state != XenbusStateClosing) continue; -- cgit v1.2.3-58-ga151 From 1080b38db49f7e3075aa9cd5a87f1587282cc0b0 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:41 +0100 Subject: xen: make use of xenbus_read_unsigned() in xen-scsifront Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. Signed-off-by: Juergen Gross Acked-by: David Vrabel --- drivers/scsi/xen-scsifront.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c index 9dc8687bf048..7e817c64f385 100644 --- a/drivers/scsi/xen-scsifront.c +++ b/drivers/scsi/xen-scsifront.c @@ -1060,13 +1060,9 @@ static void scsifront_read_backend_params(struct xenbus_device *dev, struct vscsifrnt_info *info) { unsigned int sg_grant, nr_segs; - int ret; struct Scsi_Host *host = info->host; - ret = xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg-grant", "%u", - &sg_grant); - if (ret != 1) - sg_grant = 0; + sg_grant = xenbus_read_unsigned(dev->otherend, "feature-sg-grant", 0); nr_segs = min_t(unsigned int, sg_grant, SG_ALL); nr_segs = max_t(unsigned int, nr_segs, VSCSIIF_SG_TABLESIZE); nr_segs = min_t(unsigned int, nr_segs, -- cgit v1.2.3-58-ga151 From eaf46e181ec3cc3b6eafdbe8e30fb5a03ebbde68 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:41 +0100 Subject: xen: make use of xenbus_read_unsigned() in xen-fbfront Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of the reads from int to unsigned, but these cases have been wrong before: negative values are not allowed for the modified cases. Cc: tomi.valkeinen@ti.com Cc: linux-fbdev@vger.kernel.org Signed-off-by: Juergen Gross Acked-by: David Vrabel --- drivers/video/fbdev/xen-fbfront.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) (limited to 'drivers') diff --git a/drivers/video/fbdev/xen-fbfront.c b/drivers/video/fbdev/xen-fbfront.c index 0567d517eed3..d0115a7af0a9 100644 --- a/drivers/video/fbdev/xen-fbfront.c +++ b/drivers/video/fbdev/xen-fbfront.c @@ -633,7 +633,6 @@ static void xenfb_backend_changed(struct xenbus_device *dev, enum xenbus_state backend_state) { struct xenfb_info *info = dev_get_drvdata(&dev->dev); - int val; switch (backend_state) { case XenbusStateInitialising: @@ -657,16 +656,12 @@ InitWait: if (dev->state != XenbusStateConnected) goto InitWait; /* no InitWait seen yet, fudge it */ - if (xenbus_scanf(XBT_NIL, info->xbdev->otherend, - "request-update", "%d", &val) < 0) - val = 0; - if (val) + if (xenbus_read_unsigned(info->xbdev->otherend, + "request-update", 0)) info->update_wanted = 1; - if (xenbus_scanf(XBT_NIL, dev->otherend, - "feature-resize", "%d", &val) < 0) - val = 0; - info->feature_resize = val; + info->feature_resize = xenbus_read_unsigned(dev->otherend, + "feature-resize", 0); break; case XenbusStateClosed: -- cgit v1.2.3-58-ga151 From 4e81f1caa7ff77f7fd31bd31f84b1a0dcfc8184e Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:41 +0100 Subject: xen: make use of xenbus_read_unsigned() in xen-pciback Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of the read from int to unsigned, but this case has been wrong before: negative values are not allowed for the modified case. Signed-off-by: Juergen Gross Acked-by: David Vrabel --- drivers/xen/xen-pciback/xenbus.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c index 5ce878c51d03..3f0aee0a068b 100644 --- a/drivers/xen/xen-pciback/xenbus.c +++ b/drivers/xen/xen-pciback/xenbus.c @@ -362,7 +362,7 @@ static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev) int err = 0; int num_devs; int domain, bus, slot, func; - int substate; + unsigned int substate; int i, len; char state_str[64]; char dev_str[64]; @@ -395,10 +395,8 @@ static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev) "configuration"); goto out; } - err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, state_str, - "%d", &substate); - if (err != 1) - substate = XenbusStateUnknown; + substate = xenbus_read_unsigned(pdev->xdev->nodename, state_str, + XenbusStateUnknown); switch (substate) { case XenbusStateInitialising: -- cgit v1.2.3-58-ga151 From 999c9af9e3a2535d9ad41182e93eb128e587eb84 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Mon, 31 Oct 2016 14:58:42 +0100 Subject: xen: make use of xenbus_read_unsigned() in xenbus Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of the reads from int to unsigned, but these cases have been wrong before: negative values are not allowed for the modified cases. Signed-off-by: Juergen Gross Acked-by: David Vrabel --- drivers/xen/xenbus/xenbus_probe_backend.c | 8 +------- drivers/xen/xenbus/xenbus_xs.c | 7 +++---- 2 files changed, 4 insertions(+), 11 deletions(-) (limited to 'drivers') diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c index 04f7f85a5edf..37929df829a3 100644 --- a/drivers/xen/xenbus/xenbus_probe_backend.c +++ b/drivers/xen/xenbus/xenbus_probe_backend.c @@ -224,13 +224,7 @@ static int read_frontend_details(struct xenbus_device *xendev) int xenbus_dev_is_online(struct xenbus_device *dev) { - int rc, val; - - rc = xenbus_scanf(XBT_NIL, dev->nodename, "online", "%d", &val); - if (rc != 1) - val = 0; /* no online node present */ - - return val; + return !!xenbus_read_unsigned(dev->nodename, "online", 0); } EXPORT_SYMBOL_GPL(xenbus_dev_is_online); diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index 99dfdfae42c6..6afb993c5809 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -687,7 +687,7 @@ static bool xen_strict_xenbus_quirk(void) } static void xs_reset_watches(void) { - int err, supported = 0; + int err; if (!xen_hvm_domain() || xen_initial_domain()) return; @@ -695,9 +695,8 @@ static void xs_reset_watches(void) if (xen_strict_xenbus_quirk()) return; - err = xenbus_scanf(XBT_NIL, "control", - "platform-feature-xs_reset_watches", "%d", &supported); - if (err != 1 || !supported) + if (!xenbus_read_unsigned("control", + "platform-feature-xs_reset_watches", 0)) return; err = xs_error(xs_single(XBT_NIL, XS_RESET_WATCHES, "", NULL)); -- cgit v1.2.3-58-ga151 From 0f06ac3b6616b9793b3fb5c398d94044a0423492 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 10 Nov 2016 09:55:42 +0100 Subject: xen-netback: fix error handling output The connect function prints an unintialized error code after an earlier initialization was removed: drivers/net/xen-netback/xenbus.c: In function 'connect': drivers/net/xen-netback/xenbus.c:938:3: error: 'err' may be used uninitialized in this function [-Werror=maybe-uninitialized] This prints it as -EINVAL instead, which seems to be the most appropriate error code. Before the patch that caused the warning, this would print a positive number returned by vsscanf() instead, which is also wrong. We probably don't need a backport though, as fixing the warning here should be sufficient. Fixes: f95842e7a9f2 ("xen: make use of xenbus_read_unsigned() in xen-netback") Fixes: 8d3d53b3e433 ("xen-netback: Add support for multiple queues") Signed-off-by: Arnd Bergmann Reviewed-by: Paul Durrant Signed-off-by: Juergen Gross --- drivers/net/xen-netback/xenbus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 7356e00fac54..bfed79877b8a 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -935,7 +935,7 @@ static void connect(struct backend_info *be) "multi-queue-num-queues", 1); if (requested_num_queues > xenvif_max_queues) { /* buggy or malicious guest */ - xenbus_dev_fatal(dev, err, + xenbus_dev_fatal(dev, -EINVAL, "guest requested %u queues, exceeding the maximum of %u.", requested_num_queues, xenvif_max_queues); return; -- cgit v1.2.3-58-ga151 From 1ea55e8078a4fede5c21ea195d4e96091240a6ad Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Mon, 14 Nov 2016 20:52:26 +0800 Subject: xen-platform: use builtin_pci_driver Use builtin_pci_driver() helper to simplify the code. Signed-off-by: Geliang Tang Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross --- drivers/xen/platform-pci.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c index b59c9455aae1..112ce422dc22 100644 --- a/drivers/xen/platform-pci.c +++ b/drivers/xen/platform-pci.c @@ -125,8 +125,4 @@ static struct pci_driver platform_driver = { .id_table = platform_pci_tbl, }; -static int __init platform_pci_init(void) -{ - return pci_register_driver(&platform_driver); -} -device_initcall(platform_pci_init); +builtin_pci_driver(platform_driver); -- cgit v1.2.3-58-ga151 From f97df70b1c879f764f88b25b0e67b03a5213968a Mon Sep 17 00:00:00 2001 From: Seth Forshee Date: Mon, 14 Nov 2016 11:12:56 +0000 Subject: xenfs: Use proc_create_mount_point() to create /proc/xen Mounting proc in user namespace containers fails if the xenbus filesystem is mounted on /proc/xen because this directory fails the "permanently empty" test. proc_create_mount_point() exists specifically to create such mountpoints in proc but is currently proc-internal. Export this interface to modules, then use it in xenbus when creating /proc/xen. Signed-off-by: Seth Forshee Signed-off-by: David Vrabel Signed-off-by: Juergen Gross --- drivers/xen/xenbus/xenbus_probe.c | 2 +- fs/proc/generic.c | 1 + fs/proc/internal.h | 1 - include/linux/proc_fs.h | 2 ++ 4 files changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index 33a31cfef55d..b5c1dec4a7c2 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -826,7 +826,7 @@ static int __init xenbus_init(void) * Create xenfs mountpoint in /proc for compatibility with * utilities that expect to find "xenbus" under "/proc/xen". */ - proc_mkdir("xen", NULL); + proc_create_mount_point("xen"); #endif out_error: diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 5f2dc2032c79..7eb3cefcf2a3 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -479,6 +479,7 @@ struct proc_dir_entry *proc_create_mount_point(const char *name) } return ent; } +EXPORT_SYMBOL(proc_create_mount_point); struct proc_dir_entry *proc_create_data(const char *name, umode_t mode, struct proc_dir_entry *parent, diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 5378441ec1b7..7de679572111 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -195,7 +195,6 @@ static inline bool is_empty_pde(const struct proc_dir_entry *pde) { return S_ISDIR(pde->mode) && !pde->proc_iops; } -struct proc_dir_entry *proc_create_mount_point(const char *name); /* * inode.c diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index b97bf2ef996e..8bd2f726436a 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -21,6 +21,7 @@ extern struct proc_dir_entry *proc_mkdir_data(const char *, umode_t, struct proc_dir_entry *, void *); extern struct proc_dir_entry *proc_mkdir_mode(const char *, umode_t, struct proc_dir_entry *); +struct proc_dir_entry *proc_create_mount_point(const char *name); extern struct proc_dir_entry *proc_create_data(const char *, umode_t, struct proc_dir_entry *, @@ -56,6 +57,7 @@ static inline struct proc_dir_entry *proc_symlink(const char *name, struct proc_dir_entry *parent,const char *dest) { return NULL;} static inline struct proc_dir_entry *proc_mkdir(const char *name, struct proc_dir_entry *parent) {return NULL;} +static inline struct proc_dir_entry *proc_create_mount_point(const char *name) { return NULL; } static inline struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode, struct proc_dir_entry *parent, void *data) { return NULL; } static inline struct proc_dir_entry *proc_mkdir_mode(const char *name, -- cgit v1.2.3-58-ga151 From 1eb08545c0a3a2249ad53e393383cc06163d0d16 Mon Sep 17 00:00:00 2001 From: Quentin Lambert Date: Sat, 19 Nov 2016 19:22:56 +0100 Subject: xen-scsifront: Add a missing call to kfree Most error branches following the call to kmalloc contain a call to kfree. This patch add these calls where they are missing. This issue was found with Hector. Signed-off-by: Quentin Lambert Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross --- drivers/scsi/xen-scsifront.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers') diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c index 7e817c64f385..c01316c6c7b1 100644 --- a/drivers/scsi/xen-scsifront.c +++ b/drivers/scsi/xen-scsifront.c @@ -627,6 +627,7 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act) if (scsifront_enter(info)) { spin_unlock_irq(host->host_lock); + kfree(shadow); return FAILED; } -- cgit v1.2.3-58-ga151 From 30faaafdfa0c754c91bac60f216c9f34a2bfdf7e Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Mon, 21 Nov 2016 09:56:06 -0500 Subject: xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing Commit 9c17d96500f7 ("xen/gntdev: Grant maps should not be subject to NUMA balancing") set VM_IO flag to prevent grant maps from being subjected to NUMA balancing. It was discovered recently that this flag causes get_user_pages() to always fail with -EFAULT. check_vma_flags __get_user_pages __get_user_pages_locked __get_user_pages_unlocked get_user_pages_fast iov_iter_get_pages dio_refill_pages do_direct_IO do_blockdev_direct_IO do_blockdev_direct_IO ext4_direct_IO_read generic_file_read_iter aio_run_iocb (which can happen if guest's vdisk has direct-io-safe option). To avoid this let's use VM_MIXEDMAP flag instead --- it prevents NUMA balancing just as VM_IO does and has no effect on check_vma_flags(). Cc: stable@vger.kernel.org Reported-by: Olaf Hering Suggested-by: Hugh Dickins Signed-off-by: Boris Ostrovsky Acked-by: Hugh Dickins Tested-by: Olaf Hering Signed-off-by: Juergen Gross --- drivers/xen/gntdev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index bb952121ea94..2ef2b61b69df 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -1007,7 +1007,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) vma->vm_ops = &gntdev_vmops; - vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_IO; + vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP | VM_MIXEDMAP; if (use_ptemod) vma->vm_flags |= VM_DONTCOPY; -- cgit v1.2.3-58-ga151 From b36585a0a3c169612f3105139464a2da1d3ecc03 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Wed, 23 Nov 2016 13:38:45 +0100 Subject: xen/events: use xen_vcpu_id mapping for EVTCHNOP_status EVTCHNOP_status hypercall returns Xen's idea of vcpu id so we need to compare it against xen_vcpu_id mapping, not the Linux cpu id. Suggested-by: Radim Krcmar Signed-off-by: Vitaly Kuznetsov Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross --- drivers/xen/events/events_base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 9ecfcdcdd6d6..137bd0e799e7 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -948,7 +948,7 @@ static int find_virq(unsigned int virq, unsigned int cpu) continue; if (status.status != EVTCHNSTAT_virq) continue; - if (status.u.virq == virq && status.vcpu == cpu) { + if (status.u.virq == virq && status.vcpu == xen_vcpu_nr(cpu)) { rc = port; break; } -- cgit v1.2.3-58-ga151 From 0fdb47440203ce06e09923c4d578cf3c20aef69a Mon Sep 17 00:00:00 2001 From: Pan Bian Date: Mon, 5 Dec 2016 16:23:05 +0800 Subject: xen: set error code on failures Variable rc is reset in the loop, and its value will be non-negative during the second and after repeat of the loop. If it fails to allocate memory then, it may return a non-negative integer, which indicates no error. This patch fixes the bug, assigning "-ENOMEM" to rc when kzalloc() or alloc_page() returns NULL, and removing the initialization of rc outside of the loop. Signed-off-by: Pan Bian Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross --- drivers/xen/gntalloc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c index 7a47c4c9fb1b..1bf55a32a4b3 100644 --- a/drivers/xen/gntalloc.c +++ b/drivers/xen/gntalloc.c @@ -127,18 +127,21 @@ static int add_grefs(struct ioctl_gntalloc_alloc_gref *op, struct gntalloc_gref *gref, *next; readonly = !(op->flags & GNTALLOC_FLAG_WRITABLE); - rc = -ENOMEM; for (i = 0; i < op->count; i++) { gref = kzalloc(sizeof(*gref), GFP_KERNEL); - if (!gref) + if (!gref) { + rc = -ENOMEM; goto undo; + } list_add_tail(&gref->next_gref, &queue_gref); list_add_tail(&gref->next_file, &queue_file); gref->users = 1; gref->file_index = op->index + i * PAGE_SIZE; gref->page = alloc_page(GFP_KERNEL|__GFP_ZERO); - if (!gref->page) + if (!gref->page) { + rc = -ENOMEM; goto undo; + } /* Grant foreign access to the page. */ rc = gnttab_grant_foreign_access(op->domid, -- cgit v1.2.3-58-ga151 From 2466d4b9d0c21e6c28cd63516dea65806bf5a307 Mon Sep 17 00:00:00 2001 From: Pan Bian Date: Mon, 5 Dec 2016 16:22:22 +0800 Subject: xen: xenbus: set error code on failure Variable err is initialized with 0. As a result, the return value may be 0 even if get_zeroed_page() fails to allocate memory. This patch fixes the bug, initializing err with "-ENOMEM". Signed-off-by: Pan Bian Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross --- drivers/xen/xenbus/xenbus_probe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index b5c1dec4a7c2..4bdf654041e9 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -702,7 +702,7 @@ device_initcall(xenbus_probe_initcall); */ static int __init xenstored_local_init(void) { - int err = 0; + int err = -ENOMEM; unsigned long page = 0; struct evtchn_alloc_unbound alloc_unbound; -- cgit v1.2.3-58-ga151 From 3da96be58f2c8aaa86cfe78b16f837e610dfcfe2 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 2 Dec 2016 07:15:45 +0100 Subject: xen/scsifront: don't request a slot on the ring until request is ready Instead of requesting a new slot on the ring to the backend early, do so only after all has been setup for the request to be sent. This makes error handling easier as we don't need to undo the request id allocation and ring slot allocation. Suggested-by: Jan Beulich Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross --- drivers/scsi/xen-scsifront.c | 188 +++++++++++++++++++------------------------ 1 file changed, 83 insertions(+), 105 deletions(-) (limited to 'drivers') diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c index c01316c6c7b1..9aa1fe1fc939 100644 --- a/drivers/scsi/xen-scsifront.c +++ b/drivers/scsi/xen-scsifront.c @@ -79,10 +79,13 @@ struct vscsifrnt_shadow { /* command between backend and frontend */ unsigned char act; + uint8_t nr_segments; uint16_t rqid; + uint16_t ref_rqid; unsigned int nr_grants; /* number of grants in gref[] */ struct scsiif_request_segment *sg; /* scatter/gather elements */ + struct scsiif_request_segment seg[VSCSIIF_SG_TABLESIZE]; /* Do reset or abort function. */ wait_queue_head_t wq_reset; /* reset work queue */ @@ -172,68 +175,90 @@ static void scsifront_put_rqid(struct vscsifrnt_info *info, uint32_t id) scsifront_wake_up(info); } -static struct vscsiif_request *scsifront_pre_req(struct vscsifrnt_info *info) +static int scsifront_do_request(struct vscsifrnt_info *info, + struct vscsifrnt_shadow *shadow) { struct vscsiif_front_ring *ring = &(info->ring); struct vscsiif_request *ring_req; + struct scsi_cmnd *sc = shadow->sc; uint32_t id; + int i, notify; + + if (RING_FULL(&info->ring)) + return -EBUSY; id = scsifront_get_rqid(info); /* use id in response */ if (id >= VSCSIIF_MAX_REQS) - return NULL; + return -EBUSY; - ring_req = RING_GET_REQUEST(&(info->ring), ring->req_prod_pvt); + info->shadow[id] = shadow; + shadow->rqid = id; + ring_req = RING_GET_REQUEST(&(info->ring), ring->req_prod_pvt); ring->req_prod_pvt++; - ring_req->rqid = (uint16_t)id; + ring_req->rqid = id; + ring_req->act = shadow->act; + ring_req->ref_rqid = shadow->ref_rqid; + ring_req->nr_segments = shadow->nr_segments; - return ring_req; -} + ring_req->id = sc->device->id; + ring_req->lun = sc->device->lun; + ring_req->channel = sc->device->channel; + ring_req->cmd_len = sc->cmd_len; -static void scsifront_do_request(struct vscsifrnt_info *info) -{ - struct vscsiif_front_ring *ring = &(info->ring); - int notify; + BUG_ON(sc->cmd_len > VSCSIIF_MAX_COMMAND_SIZE); + + memcpy(ring_req->cmnd, sc->cmnd, sc->cmd_len); + + ring_req->sc_data_direction = (uint8_t)sc->sc_data_direction; + ring_req->timeout_per_command = sc->request->timeout / HZ; + + for (i = 0; i < (shadow->nr_segments & ~VSCSIIF_SG_GRANT); i++) + ring_req->seg[i] = shadow->seg[i]; RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(ring, notify); if (notify) notify_remote_via_irq(info->irq); + + return 0; } -static void scsifront_gnttab_done(struct vscsifrnt_info *info, uint32_t id) +static void scsifront_gnttab_done(struct vscsifrnt_info *info, + struct vscsifrnt_shadow *shadow) { - struct vscsifrnt_shadow *s = info->shadow[id]; int i; - if (s->sc->sc_data_direction == DMA_NONE) + if (shadow->sc->sc_data_direction == DMA_NONE) return; - for (i = 0; i < s->nr_grants; i++) { - if (unlikely(gnttab_query_foreign_access(s->gref[i]) != 0)) { + for (i = 0; i < shadow->nr_grants; i++) { + if (unlikely(gnttab_query_foreign_access(shadow->gref[i]))) { shost_printk(KERN_ALERT, info->host, KBUILD_MODNAME "grant still in use by backend\n"); BUG(); } - gnttab_end_foreign_access(s->gref[i], 0, 0UL); + gnttab_end_foreign_access(shadow->gref[i], 0, 0UL); } - kfree(s->sg); + kfree(shadow->sg); } static void scsifront_cdb_cmd_done(struct vscsifrnt_info *info, struct vscsiif_response *ring_rsp) { + struct vscsifrnt_shadow *shadow; struct scsi_cmnd *sc; uint32_t id; uint8_t sense_len; id = ring_rsp->rqid; - sc = info->shadow[id]->sc; + shadow = info->shadow[id]; + sc = shadow->sc; BUG_ON(sc == NULL); - scsifront_gnttab_done(info, id); + scsifront_gnttab_done(info, shadow); scsifront_put_rqid(info, id); sc->result = ring_rsp->rslt; @@ -366,7 +391,6 @@ static void scsifront_finish_all(struct vscsifrnt_info *info) static int map_data_for_request(struct vscsifrnt_info *info, struct scsi_cmnd *sc, - struct vscsiif_request *ring_req, struct vscsifrnt_shadow *shadow) { grant_ref_t gref_head; @@ -379,7 +403,6 @@ static int map_data_for_request(struct vscsifrnt_info *info, struct scatterlist *sg; struct scsiif_request_segment *seg; - ring_req->nr_segments = 0; if (sc->sc_data_direction == DMA_NONE || !data_len) return 0; @@ -398,7 +421,7 @@ static int map_data_for_request(struct vscsifrnt_info *info, if (!shadow->sg) return -ENOMEM; } - seg = shadow->sg ? : ring_req->seg; + seg = shadow->sg ? : shadow->seg; err = gnttab_alloc_grant_references(seg_grants + data_grants, &gref_head); @@ -423,9 +446,9 @@ static int map_data_for_request(struct vscsifrnt_info *info, info->dev->otherend_id, xen_page_to_gfn(page), 1); shadow->gref[ref_cnt] = ref; - ring_req->seg[ref_cnt].gref = ref; - ring_req->seg[ref_cnt].offset = (uint16_t)off; - ring_req->seg[ref_cnt].length = (uint16_t)bytes; + shadow->seg[ref_cnt].gref = ref; + shadow->seg[ref_cnt].offset = (uint16_t)off; + shadow->seg[ref_cnt].length = (uint16_t)bytes; page++; len -= bytes; @@ -473,44 +496,14 @@ static int map_data_for_request(struct vscsifrnt_info *info, } if (seg_grants) - ring_req->nr_segments = VSCSIIF_SG_GRANT | seg_grants; + shadow->nr_segments = VSCSIIF_SG_GRANT | seg_grants; else - ring_req->nr_segments = (uint8_t)ref_cnt; + shadow->nr_segments = (uint8_t)ref_cnt; shadow->nr_grants = ref_cnt; return 0; } -static struct vscsiif_request *scsifront_command2ring( - struct vscsifrnt_info *info, struct scsi_cmnd *sc, - struct vscsifrnt_shadow *shadow) -{ - struct vscsiif_request *ring_req; - - memset(shadow, 0, sizeof(*shadow)); - - ring_req = scsifront_pre_req(info); - if (!ring_req) - return NULL; - - info->shadow[ring_req->rqid] = shadow; - shadow->rqid = ring_req->rqid; - - ring_req->id = sc->device->id; - ring_req->lun = sc->device->lun; - ring_req->channel = sc->device->channel; - ring_req->cmd_len = sc->cmd_len; - - BUG_ON(sc->cmd_len > VSCSIIF_MAX_COMMAND_SIZE); - - memcpy(ring_req->cmnd, sc->cmnd, sc->cmd_len); - - ring_req->sc_data_direction = (uint8_t)sc->sc_data_direction; - ring_req->timeout_per_command = sc->request->timeout / HZ; - - return ring_req; -} - static int scsifront_enter(struct vscsifrnt_info *info) { if (info->pause) @@ -536,36 +529,25 @@ static int scsifront_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc) { struct vscsifrnt_info *info = shost_priv(shost); - struct vscsiif_request *ring_req; struct vscsifrnt_shadow *shadow = scsi_cmd_priv(sc); unsigned long flags; int err; - uint16_t rqid; + + sc->result = 0; + memset(shadow, 0, sizeof(*shadow)); + + shadow->sc = sc; + shadow->act = VSCSIIF_ACT_SCSI_CDB; spin_lock_irqsave(shost->host_lock, flags); if (scsifront_enter(info)) { spin_unlock_irqrestore(shost->host_lock, flags); return SCSI_MLQUEUE_HOST_BUSY; } - if (RING_FULL(&info->ring)) - goto busy; - ring_req = scsifront_command2ring(info, sc, shadow); - if (!ring_req) - goto busy; - - sc->result = 0; - - rqid = ring_req->rqid; - ring_req->act = VSCSIIF_ACT_SCSI_CDB; - - shadow->sc = sc; - shadow->act = VSCSIIF_ACT_SCSI_CDB; - - err = map_data_for_request(info, sc, ring_req, shadow); + err = map_data_for_request(info, sc, shadow); if (err < 0) { pr_debug("%s: err %d\n", __func__, err); - scsifront_put_rqid(info, rqid); scsifront_return(info); spin_unlock_irqrestore(shost->host_lock, flags); if (err == -ENOMEM) @@ -575,7 +557,11 @@ static int scsifront_queuecommand(struct Scsi_Host *shost, return 0; } - scsifront_do_request(info); + if (scsifront_do_request(info, shadow)) { + scsifront_gnttab_done(info, shadow); + goto busy; + } + scsifront_return(info); spin_unlock_irqrestore(shost->host_lock, flags); @@ -598,26 +584,30 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act) struct Scsi_Host *host = sc->device->host; struct vscsifrnt_info *info = shost_priv(host); struct vscsifrnt_shadow *shadow, *s = scsi_cmd_priv(sc); - struct vscsiif_request *ring_req; int err = 0; - shadow = kmalloc(sizeof(*shadow), GFP_NOIO); + shadow = kzalloc(sizeof(*shadow), GFP_NOIO); if (!shadow) return FAILED; + shadow->act = act; + shadow->rslt_reset = RSLT_RESET_WAITING; + shadow->sc = sc; + shadow->ref_rqid = s->rqid; + init_waitqueue_head(&shadow->wq_reset); + spin_lock_irq(host->host_lock); for (;;) { - if (!RING_FULL(&info->ring)) { - ring_req = scsifront_command2ring(info, sc, shadow); - if (ring_req) - break; - } - if (err || info->pause) { - spin_unlock_irq(host->host_lock); - kfree(shadow); - return FAILED; - } + if (scsifront_enter(info)) + goto fail; + + if (!scsifront_do_request(info, shadow)) + break; + + scsifront_return(info); + if (err) + goto fail; info->wait_ring_available = 1; spin_unlock_irq(host->host_lock); err = wait_event_interruptible(info->wq_sync, @@ -625,23 +615,6 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act) spin_lock_irq(host->host_lock); } - if (scsifront_enter(info)) { - spin_unlock_irq(host->host_lock); - kfree(shadow); - return FAILED; - } - - ring_req->act = act; - ring_req->ref_rqid = s->rqid; - - shadow->act = act; - shadow->rslt_reset = RSLT_RESET_WAITING; - init_waitqueue_head(&shadow->wq_reset); - - ring_req->nr_segments = 0; - - scsifront_do_request(info); - spin_unlock_irq(host->host_lock); err = wait_event_interruptible(shadow->wq_reset, shadow->wait_reset); spin_lock_irq(host->host_lock); @@ -660,6 +633,11 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act) scsifront_return(info); spin_unlock_irq(host->host_lock); return err; + +fail: + spin_unlock_irq(host->host_lock); + kfree(shadow); + return FAILED; } static int scsifront_eh_abort_handler(struct scsi_cmnd *sc) -- cgit v1.2.3-58-ga151 From 581d21a2d02a798ee34e56dbfa13f891b3a90c30 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Fri, 9 Dec 2016 14:41:13 +0000 Subject: xenbus: fix deadlock on writes to /proc/xen/xenbus /proc/xen/xenbus does not work correctly. A read blocked waiting for a xenstore message holds the mutex needed for atomic file position updates. This blocks any writes on the same file handle, which can deadlock if the write is needed to unblock the read. Clear FMODE_ATOMIC_POS when opening this device to always get character device like sematics. Signed-off-by: David Vrabel Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross --- drivers/xen/xenbus/xenbus_dev_frontend.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers') diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c index 1e8be12ebb55..6c0ead4be784 100644 --- a/drivers/xen/xenbus/xenbus_dev_frontend.c +++ b/drivers/xen/xenbus/xenbus_dev_frontend.c @@ -538,6 +538,8 @@ static int xenbus_file_open(struct inode *inode, struct file *filp) nonseekable_open(inode, filp); + filp->f_mode &= ~FMODE_ATOMIC_POS; /* cdev-style semantics */ + u = kzalloc(sizeof(*u), GFP_KERNEL); if (u == NULL) return -ENOMEM; -- cgit v1.2.3-58-ga151 From 709613ad2b3c9eaeb2a3e24284b7c8feffc17326 Mon Sep 17 00:00:00 2001 From: Ross Lagerwall Date: Fri, 9 Dec 2016 17:10:22 +0000 Subject: xen/balloon: Only mark a page as managed when it is released Only mark a page as managed when it is released back to the allocator. This ensures that the managed page count does not get falsely increased when a VM is running. Correspondingly change it so that pages are marked as unmanaged after getting them from the allocator. Signed-off-by: Ross Lagerwall Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross --- drivers/xen/balloon.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'drivers') diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index e4db19e88ab1..db107fa50ca1 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -180,7 +180,6 @@ static void __balloon_append(struct page *page) static void balloon_append(struct page *page) { __balloon_append(page); - adjust_managed_page_count(page, -1); } /* balloon_retrieve: rescue a page from the balloon, if it is not empty. */ @@ -201,8 +200,6 @@ static struct page *balloon_retrieve(bool require_lowmem) else balloon_stats.balloon_low--; - adjust_managed_page_count(page, 1); - return page; } @@ -478,7 +475,7 @@ static enum bp_state increase_reservation(unsigned long nr_pages) #endif /* Relinquish the page back to the allocator. */ - __free_reserved_page(page); + free_reserved_page(page); } balloon_stats.current_pages += rc; @@ -509,6 +506,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) state = BP_EAGAIN; break; } + adjust_managed_page_count(page, -1); scrub_page(page); list_add(&page->lru, &pages); } -- cgit v1.2.3-58-ga151