Merge 4.4.173 into android-4.4

Changes in 4.4.173
	net: Fix usage of pskb_trim_rcsum
	openvswitch: Avoid OOB read when parsing flow nlattrs
	net: ipv4: Fix memory leak in network namespace dismantle
	net_sched: refetch skb protocol for each filter
	net: bridge: Fix ethernet header pointer before check skb forwardable
	USB: serial: simple: add Motorola Tetra TPG2200 device id
	USB: serial: pl2303: add new PID to support PL2303TB
	ASoC: atom: fix a missing check of snd_pcm_lib_malloc_pages
	ARC: perf: map generic branches to correct hardware condition
	s390/early: improve machine detection
	s390/smp: fix CPU hotplug deadlock with CPU rescan
	char/mwave: fix potential Spectre v1 vulnerability
	staging: rtl8188eu: Add device code for D-Link DWA-121 rev B1
	tty: Handle problem if line discipline does not have receive_buf
	tty/n_hdlc: fix __might_sleep warning
	CIFS: Fix possible hang during async MTU reads and writes
	Input: xpad - add support for SteelSeries Stratus Duo
	KVM: x86: Fix single-step debugging
	x86/kaslr: Fix incorrect i8254 outb() parameters
	can: dev: __can_get_echo_skb(): fix bogous check for non-existing skb by removing it
	can: bcm: check timer values before ktime conversion
	vt: invoke notifier on screen size change
	perf unwind: Unwind with libdw doesn't take symfs into account
	perf unwind: Take pgoff into account when reporting elf to libdwfl
	irqchip/gic-v3-its: Align PCI Multi-MSI allocation on their size
	arm64: mm: remove page_mapping check in __sync_icache_dcache
	f2fs: read page index before freeing
	Revert "loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl()"
	Revert "loop: Get rid of loop_index_mutex"
	Revert "loop: Fold __loop_release into loop_release"
	s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU
	fs: add the fsnotify call to vfs_iter_write
	ipv6: Consider sk_bound_dev_if when binding a socket to an address
	l2tp: copy 4 more bytes to linear part if necessary
	net/mlx4_core: Add masking for a few queries on HCA caps
	netrom: switch to sock timer API
	net/rose: fix NULL ax25_cb kernel panic
	ucc_geth: Reset BQL queue when stopping device
	l2tp: remove l2specific_len dependency in l2tp_core
	l2tp: fix reading optional fields of L2TPv3
	CIFS: Do not count -ENODATA as failure for query directory
	fs/dcache: Fix incorrect nr_dentry_unused accounting in shrink_dcache_sb()
	ARM: cns3xxx: Fix writing to wrong PCI config registers after alignment
	arm64: hyp-stub: Forbid kprobing of the hyp-stub
	gfs2: Revert "Fix loop in gfs2_rbm_find"
	platform/x86: asus-nb-wmi: Map 0x35 to KEY_SCREENLOCK
	platform/x86: asus-nb-wmi: Drop mapping of 0x33 and 0x34 scan codes
	mmc: sdhci-iproc: handle mmc_of_parse() errors during probe
	kernel/exit.c: release ptraced tasks before zap_pid_ns_processes
	mm, oom: fix use-after-free in oom_kill_process
	cifs: Always resolve hostname before reconnecting
	drivers: core: Remove glue dirs from sysfs earlier
	mm: migrate: don't rely on __PageMovable() of newpage after unlocking it
	fs: don't scan the inode cache before SB_BORN is set
	Linux 4.4.173

Change-Id: Ifc01c8b56016e9145bb67258f91dfc6b6983354c
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

7 files changed, 87 insertions, 18 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 1eeb4780c3ed..eacf57c24ca9 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -48,6 +48,7 @@
 #include "cifs_unicode.h"
 #include "cifs_debug.h"
 #include "cifs_fs_sb.h"
+#include "dns_resolve.h"
 #include "ntlmssp.h"
 #include "nterr.h"
 #include "rfc1002pdu.h"
@@ -304,6 +305,53 @@ static int cifs_setup_volume_info(struct smb_vol *volume_info, char *mount_data,
 					const char *devname);
 
 /*
+ * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
+ * get their ip addresses changed at some point.
+ *
+ * This should be called with server->srv_mutex held.
+ */
+#ifdef CONFIG_CIFS_DFS_UPCALL
+static int reconn_set_ipaddr(struct TCP_Server_Info *server)
+{
+	int rc;
+	int len;
+	char *unc, *ipaddr = NULL;
+
+	if (!server->hostname)
+		return -EINVAL;
+
+	len = strlen(server->hostname) + 3;
+
+	unc = kmalloc(len, GFP_KERNEL);
+	if (!unc) {
+		cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
+		return -ENOMEM;
+	}
+	snprintf(unc, len, "\\\\%s", server->hostname);
+
+	rc = dns_resolve_server_name_to_ip(unc, &ipaddr);
+	kfree(unc);
+
+	if (rc < 0) {
+		cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
+			 __func__, server->hostname, rc);
+		return rc;
+	}
+
+	rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
+				  strlen(ipaddr));
+	kfree(ipaddr);
+
+	return !rc ? -1 : 0;
+}
+#else
+static inline int reconn_set_ipaddr(struct TCP_Server_Info *server)
+{
+	return 0;
+}
+#endif
+
+/*
  * cifs tcp session reconnection
  *
  * mark tcp session as reconnecting so temporarily locked
@@ -400,6 +448,11 @@ cifs_reconnect(struct TCP_Server_Info *server)
 		rc = generic_ip_connect(server);
 		if (rc) {
 			cifs_dbg(FYI, "reconnect error %d\n", rc);
+			rc = reconn_set_ipaddr(server);
+			if (rc) {
+				cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
+					 __func__, rc);
+			}
 			mutex_unlock(&server->srv_mutex);
 			msleep(3000);
 		} else {
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 2725085a3f9f..eae3cdffaf7f 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -143,14 +143,14 @@ smb2_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
 
 			scredits = server->credits;
 			/* can deadlock with reopen */
-			if (scredits == 1) {
+			if (scredits <= 8) {
 				*num = SMB2_MAX_BUFFER_SIZE;
 				*credits = 0;
 				break;
 			}
 
-			/* leave one credit for a possible reopen */
-			scredits--;
+			/* leave some credits for reopen and other ops */
+			scredits -= 8;
 			*num = min_t(unsigned int, size,
 				     scredits * SMB2_MAX_BUFFER_SIZE);
 
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index f7111bb88ec1..5e21d58c49ef 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2523,8 +2523,8 @@ SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
 		if (rc == -ENODATA && rsp->hdr.Status == STATUS_NO_MORE_FILES) {
 			srch_inf->endOfSearch = true;
 			rc = 0;
-		}
-		cifs_stats_fail_inc(tcon, SMB2_QUERY_DIRECTORY_HE);
+		} else
+			cifs_stats_fail_inc(tcon, SMB2_QUERY_DIRECTORY_HE);
 		goto qdir_exit;
 	}
 
diff --git a/fs/dcache.c b/fs/dcache.c
index b056cf8271a5..760f997fe8c6 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1155,15 +1155,11 @@ static enum lru_status dentry_lru_isolate_shrink(struct list_head *item,
  */
 void shrink_dcache_sb(struct super_block *sb)
 {
-	long freed;
-
 	do {
 		LIST_HEAD(dispose);
 
-		freed = list_lru_walk(&sb->s_dentry_lru,
+		list_lru_walk(&sb->s_dentry_lru,
 			dentry_lru_isolate_shrink, &dispose, 1024);
-
-		this_cpu_sub(nr_dentry_unused, freed);
 		shrink_dentry_list(&dispose);
 		cond_resched();
 	} while (list_lru_count(&sb->s_dentry_lru) > 0);
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 763fe7737065..ef24894edecc 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1720,9 +1720,9 @@ static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state, u32 *minext,
 			goto next_iter;
 		}
 		if (ret == -E2BIG) {
-			n += rbm->bii - initial_bii;
 			rbm->bii = 0;
 			rbm->offset = 0;
+			n += (rbm->bii - initial_bii);
 			goto res_covered_end_of_rgrp;
 		}
 		return ret;
diff --git a/fs/read_write.c b/fs/read_write.c
index bfd1a5dddf6e..16e554ba885d 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -363,8 +363,10 @@ ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos)
 	iter->type |= WRITE;
 	ret = file->f_op->write_iter(&kiocb, iter);
 	BUG_ON(ret == -EIOCBQUEUED);
-	if (ret > 0)
+	if (ret > 0) {
 		*ppos = kiocb.ki_pos;
+		fsnotify_modify(file);
+	}
 	return ret;
 }
 EXPORT_SYMBOL(vfs_iter_write);
diff --git a/fs/super.c b/fs/super.c
index 652c9e6b6b92..eb27955a229a 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -118,13 +118,23 @@ static unsigned long super_cache_count(struct shrinker *shrink,
 	sb = container_of(shrink, struct super_block, s_shrink);
 
 	/*
-	 * Don't call trylock_super as it is a potential
-	 * scalability bottleneck. The counts could get updated
-	 * between super_cache_count and super_cache_scan anyway.
-	 * Call to super_cache_count with shrinker_rwsem held
-	 * ensures the safety of call to list_lru_shrink_count() and
-	 * s_op->nr_cached_objects().
+	 * We don't call trylock_super() here as it is a scalability bottleneck,
+	 * so we're exposed to partial setup state. The shrinker rwsem does not
+	 * protect filesystem operations backing list_lru_shrink_count() or
+	 * s_op->nr_cached_objects(). Counts can change between
+	 * super_cache_count and super_cache_scan, so we really don't need locks
+	 * here.
+	 *
+	 * However, if we are currently mounting the superblock, the underlying
+	 * filesystem might be in a state of partial construction and hence it
+	 * is dangerous to access it.  trylock_super() uses a MS_BORN check to
+	 * avoid this situation, so do the same here. The memory barrier is
+	 * matched with the one in mount_fs() as we don't hold locks here.
 	 */
+	if (!(sb->s_flags & MS_BORN))
+		return 0;
+	smp_rmb();
+
 	if (sb->s_op && sb->s_op->nr_cached_objects)
 		total_objects = sb->s_op->nr_cached_objects(sb, sc);
 
@@ -1151,6 +1161,14 @@ mount_fs(struct file_system_type *type, int flags, const char *name, struct vfsm
 	sb = root->d_sb;
 	BUG_ON(!sb);
 	WARN_ON(!sb->s_bdi);
+
+	/*
+	 * Write barrier is for super_cache_count(). We place it before setting
+	 * MS_BORN as the data dependency between the two functions is the
+	 * superblock structure contents that we just set up, not the MS_BORN
+	 * flag.
+	 */
+	smp_wmb();
 	sb->s_flags |= MS_BORN;
 
 	error = security_sb_kern_mount(sb, flags, secdata);