From 09ee96b21456883e108c3b00597bb37ec512151b Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@redhat.com>
Date: Thu, 26 Feb 2015 11:41:28 -0500
Subject: dm snapshot: suspend merging snapshot when doing exception handover

The "dm snapshot: suspend origin when doing exception handover" commit
fixed a exception store handover bug associated with pending exceptions
to the "snapshot-origin" target.

However, a similar problem exists in snapshot merging.  When snapshot
merging is in progress, we use the target "snapshot-merge" instead of
"snapshot-origin".  Consequently, during exception store handover, we
must find the snapshot-merge target and suspend its associated
mapped_device.

To avoid lockdep warnings, the target must be suspended and resumed
without holding _origins_lock.

Introduce a dm_hold() function that grabs a reference on a
mapped_device, but unlike dm_get(), it doesn't crash if the device has
the DMF_FREEING flag set, it returns an error in this case.

In snapshot_resume() we grab the reference to the origin device using
dm_hold() while holding _origins_lock (_origins_lock guarantees that the
device won't disappear).  Then we release _origins_lock, suspend the
device and grab _origins_lock again.

NOTE to stable@ people:
When backporting to kernels 3.18 and older, use dm_internal_suspend and
dm_internal_resume instead of dm_internal_suspend_fast and
dm_internal_resume_fast.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
---
 include/linux/device-mapper.h | 1 +
 1 file changed, 1 insertion(+)

(limited to 'include')

diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 2646aed1d3fe..fd23978d93fe 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -375,6 +375,7 @@ int dm_create(int minor, struct mapped_device **md);
  */
 struct mapped_device *dm_get_md(dev_t dev);
 void dm_get(struct mapped_device *md);
+int dm_hold(struct mapped_device *md);
 void dm_put(struct mapped_device *md);
 
 /*
-- 
cgit v1.2.3


From 4017a7ee693d1cae6735c0dac21594a7c6416c4c Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Mon, 2 Mar 2015 01:10:28 +0100
Subject: netfilter: restore rule tracing via nfnetlink_log
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Since fab4085 ("netfilter: log: nf_log_packet() as real unified
interface"), the loginfo structure that is passed to nf_log_packet() is
used to explicitly indicate the logger type you want to use.

This is a problem for people tracing rules through nfnetlink_log since
packets are always routed to the NF_LOG_TYPE logger after the
aforementioned patch.

We can fix this by removing the trace loginfo structures, but that still
changes the log level from 4 to 5 for tracing messages and there may be
someone relying on this outthere. So let's just introduce a new
nf_log_trace() function that restores the former behaviour.

Reported-by: Markus Kötter <koetter@rrzn.uni-hannover.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/net/netfilter/nf_log.h  | 10 ++++++++++
 net/ipv4/netfilter/ip_tables.c  |  6 +++---
 net/ipv6/netfilter/ip6_tables.c |  6 +++---
 net/netfilter/nf_log.c          | 24 ++++++++++++++++++++++++
 net/netfilter/nf_tables_core.c  |  8 ++++----
 5 files changed, 44 insertions(+), 10 deletions(-)

(limited to 'include')

diff --git a/include/net/netfilter/nf_log.h b/include/net/netfilter/nf_log.h
index 534e1f2ac4fc..57639fca223a 100644
--- a/include/net/netfilter/nf_log.h
+++ b/include/net/netfilter/nf_log.h
@@ -79,6 +79,16 @@ void nf_log_packet(struct net *net,
 		   const struct nf_loginfo *li,
 		   const char *fmt, ...);
 
+__printf(8, 9)
+void nf_log_trace(struct net *net,
+		  u_int8_t pf,
+		  unsigned int hooknum,
+		  const struct sk_buff *skb,
+		  const struct net_device *in,
+		  const struct net_device *out,
+		  const struct nf_loginfo *li,
+		  const char *fmt, ...);
+
 struct nf_log_buf;
 
 struct nf_log_buf *nf_log_buf_open(void);
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 99e810f84671..cf5e82f39d3b 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -272,9 +272,9 @@ static void trace_packet(const struct sk_buff *skb,
 		    &chainname, &comment, &rulenum) != 0)
 			break;
 
-	nf_log_packet(net, AF_INET, hook, skb, in, out, &trace_loginfo,
-		      "TRACE: %s:%s:%s:%u ",
-		      tablename, chainname, comment, rulenum);
+	nf_log_trace(net, AF_INET, hook, skb, in, out, &trace_loginfo,
+		     "TRACE: %s:%s:%s:%u ",
+		     tablename, chainname, comment, rulenum);
 }
 #endif
 
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index e080fbbbc0e5..bb00c6f2a885 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -298,9 +298,9 @@ static void trace_packet(const struct sk_buff *skb,
 		    &chainname, &comment, &rulenum) != 0)
 			break;
 
-	nf_log_packet(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
-		      "TRACE: %s:%s:%s:%u ",
-		      tablename, chainname, comment, rulenum);
+	nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
+		     "TRACE: %s:%s:%s:%u ",
+		     tablename, chainname, comment, rulenum);
 }
 #endif
 
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index 0d8448f19dfe..675d12c69e32 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -212,6 +212,30 @@ void nf_log_packet(struct net *net,
 }
 EXPORT_SYMBOL(nf_log_packet);
 
+void nf_log_trace(struct net *net,
+		  u_int8_t pf,
+		  unsigned int hooknum,
+		  const struct sk_buff *skb,
+		  const struct net_device *in,
+		  const struct net_device *out,
+		  const struct nf_loginfo *loginfo, const char *fmt, ...)
+{
+	va_list args;
+	char prefix[NF_LOG_PREFIXLEN];
+	const struct nf_logger *logger;
+
+	rcu_read_lock();
+	logger = rcu_dereference(net->nf.nf_loggers[pf]);
+	if (logger) {
+		va_start(args, fmt);
+		vsnprintf(prefix, sizeof(prefix), fmt, args);
+		va_end(args);
+		logger->logfn(net, pf, hooknum, skb, in, out, loginfo, prefix);
+	}
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(nf_log_trace);
+
 #define S_SIZE (1024 - (sizeof(unsigned int) + 1))
 
 struct nf_log_buf {
diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
index 3b90eb2b2c55..2d298dccb6dd 100644
--- a/net/netfilter/nf_tables_core.c
+++ b/net/netfilter/nf_tables_core.c
@@ -94,10 +94,10 @@ static void nft_trace_packet(const struct nft_pktinfo *pkt,
 {
 	struct net *net = dev_net(pkt->in ? pkt->in : pkt->out);
 
-	nf_log_packet(net, pkt->xt.family, pkt->ops->hooknum, pkt->skb, pkt->in,
-		      pkt->out, &trace_loginfo, "TRACE: %s:%s:%s:%u ",
-		      chain->table->name, chain->name, comments[type],
-		      rulenum);
+	nf_log_trace(net, pkt->xt.family, pkt->ops->hooknum, pkt->skb, pkt->in,
+		     pkt->out, &trace_loginfo, "TRACE: %s:%s:%s:%u ",
+		     chain->table->name, chain->name, comments[type],
+		     rulenum);
 }
 
 unsigned int
-- 
cgit v1.2.3


From 9bc6548f372d8c829235095d91de99d8df79db6e Mon Sep 17 00:00:00 2001
From: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
Date: Thu, 19 Mar 2015 14:30:13 +0100
Subject: target: do not reject FUA CDBs when write cache is enabled but
 emulate_write_cache is 0

A check that rejects a CDB with FUA bit set if no write cache is
emulated was added by the following commit:

  fde9f50 target: Add sanity checks for DPO/FUA bit usage

The condition is as follows:

  if (!dev->dev_attrib.emulate_fua_write ||
      !dev->dev_attrib.emulate_write_cache)

However, this check is wrong if the backend device supports WCE but
"emulate_write_cache" is disabled.

This patch uses se_dev_check_wce() (previously named
spc_check_dev_wce) to invoke transport->get_write_cache() if the
device has a write cache or check the "emulate_write_cache" attribute
otherwise.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/target_core_device.c  | 12 ++++++++++++
 drivers/target/target_core_sbc.c     |  3 +--
 drivers/target/target_core_spc.c     | 19 +++----------------
 include/target/target_core_backend.h |  1 +
 4 files changed, 17 insertions(+), 18 deletions(-)

(limited to 'include')

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 7fc5eae875de..79b4ec3ca2db 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -650,6 +650,18 @@ static u32 se_dev_align_max_sectors(u32 max_sectors, u32 block_size)
 	return aligned_max_sectors;
 }
 
+bool se_dev_check_wce(struct se_device *dev)
+{
+	bool wce = false;
+
+	if (dev->transport->get_write_cache)
+		wce = dev->transport->get_write_cache(dev);
+	else if (dev->dev_attrib.emulate_write_cache > 0)
+		wce = true;
+
+	return wce;
+}
+
 int se_dev_set_max_unmap_lba_count(
 	struct se_device *dev,
 	u32 max_unmap_lba_count)
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 9a2f9d3a6e70..3e7297411110 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -708,8 +708,7 @@ sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 		}
 	}
 	if (cdb[1] & 0x8) {
-		if (!dev->dev_attrib.emulate_fua_write ||
-		    !dev->dev_attrib.emulate_write_cache) {
+		if (!dev->dev_attrib.emulate_fua_write || !se_dev_check_wce(dev)) {
 			pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 			       " does not advertise support for FUA write\n",
 			       cdb[0]);
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 460e93109473..6c8bd6bc175c 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -454,19 +454,6 @@ check_scsi_name:
 }
 EXPORT_SYMBOL(spc_emulate_evpd_83);
 
-static bool
-spc_check_dev_wce(struct se_device *dev)
-{
-	bool wce = false;
-
-	if (dev->transport->get_write_cache)
-		wce = dev->transport->get_write_cache(dev);
-	else if (dev->dev_attrib.emulate_write_cache > 0)
-		wce = true;
-
-	return wce;
-}
-
 /* Extended INQUIRY Data VPD Page */
 static sense_reason_t
 spc_emulate_evpd_86(struct se_cmd *cmd, unsigned char *buf)
@@ -490,7 +477,7 @@ spc_emulate_evpd_86(struct se_cmd *cmd, unsigned char *buf)
 	buf[5] = 0x07;
 
 	/* If WriteCache emulation is enabled, set V_SUP */
-	if (spc_check_dev_wce(dev))
+	if (se_dev_check_wce(dev))
 		buf[6] = 0x01;
 	/* If an LBA map is present set R_SUP */
 	spin_lock(&cmd->se_dev->t10_alua.lba_map_lock);
@@ -897,7 +884,7 @@ static int spc_modesense_caching(struct se_cmd *cmd, u8 pc, u8 *p)
 	if (pc == 1)
 		goto out;
 
-	if (spc_check_dev_wce(dev))
+	if (se_dev_check_wce(dev))
 		p[2] = 0x04; /* Write Cache Enable */
 	p[12] = 0x20; /* Disabled Read Ahead */
 
@@ -1009,7 +996,7 @@ static sense_reason_t spc_emulate_modesense(struct se_cmd *cmd)
 	     (cmd->se_deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY)))
 		spc_modesense_write_protect(&buf[length], type);
 
-	if ((spc_check_dev_wce(dev)) &&
+	if ((se_dev_check_wce(dev)) &&
 	    (dev->dev_attrib.emulate_fua_write > 0))
 		spc_modesense_dpofua(&buf[length], type);
 
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index db81c65b8f48..d61be7297b2c 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -111,6 +111,7 @@ void	array_free(void *array, int n);
 void	target_core_setup_sub_cits(struct se_subsystem_api *);
 
 /* attribute helpers from target_core_device.c for backend drivers */
+bool	se_dev_check_wce(struct se_device *);
 int	se_dev_set_max_unmap_lba_count(struct se_device *, u32);
 int	se_dev_set_max_unmap_block_desc_count(struct se_device *, u32);
 int	se_dev_set_unmap_granularity(struct se_device *, u32);
-- 
cgit v1.2.3