Merge 4.4.216 into android-4.4-p

Changes in 4.4.216
	iwlwifi: pcie: fix rb_allocator workqueue allocation
	ext4: fix potential race between online resizing and write operations
	ext4: fix potential race between s_flex_groups online resizing and access
	ext4: fix potential race between s_group_info online resizing and access
	ipmi:ssif: Handle a possible NULL pointer reference
	mac80211: consider more elements in parsing CRC
	cfg80211: check wiphy driver existence for drvinfo report
	cifs: Fix mode output in debugging statements
	cfg80211: add missing policy for NL80211_ATTR_STATUS_CODE
	sysrq: Restore original console_loglevel when sysrq disabled
	sysrq: Remove duplicated sysrq message
	net: fib_rules: Correctly set table field when table number exceeds 8 bits
	net: phy: restore mdio regs in the iproc mdio driver
	ipv6: Fix nlmsg_flags when splitting a multipath route
	ipv6: Fix route replacement with dev-only route
	sctp: move the format error check out of __sctp_sf_do_9_1_abort
	nfc: pn544: Fix occasional HW initialization failure
	net: sched: correct flower port blocking
	ext4: potential crash on allocation error in ext4_alloc_flex_bg_array()
	audit: fix error handling in audit_data_to_entry()
	HID: core: fix off-by-one memset in hid_report_raw_event()
	HID: core: increase HID report buffer size to 8KiB
	HID: hiddev: Fix race in in hiddev_disconnect()
	MIPS: VPE: Fix a double free and a memory leak in 'release_vpe()'
	i2c: jz4780: silence log flood on txabrt
	ecryptfs: Fix up bad backport of fe2e082f5da5b4a0a92ae32978f81507ef37ec66
	include/linux/bitops.h: introduce BITS_PER_TYPE
	net: netlink: cap max groups which will be considered in netlink_bind()
	namei: only return -ECHILD from follow_dotdot_rcu()
	KVM: Check for a bad hva before dropping into the ghc slow path
	slip: stop double free sl->dev in slip_open
	mm: make page ref count overflow check tighter and more explicit
	mm: add 'try_get_page()' helper function
	mm, gup: remove broken VM_BUG_ON_PAGE compound check for hugepages
	mm, gup: ensure real head page is ref-counted when using hugepages
	mm: prevent get_user_pages() from overflowing page refcount
	pipe: add pipe_buf_get() helper
	fs: prevent page refcount overflow in pipe_buf_get
	audit: always check the netlink payload length in audit_receive_msg()
	serial: ar933x_uart: set UART_CS_{RX,TX}_READY_ORIDE
	usb: gadget: ffs: ffs_aio_cancel(): Save/restore IRQ flags
	usb: gadget: serial: fix Tx stall after buffer overflow
	drm: msm: Fix return type of dsi_mgr_connector_mode_valid for kCFI
	drm/msm/dsi: save pll state before dsi host is powered off
	net: ks8851-ml: Remove 8-bit bus accessors
	net: ks8851-ml: Fix 16-bit data access
	net: ks8851-ml: Fix 16-bit IO operation
	watchdog: da9062: do not ping the hw during stop()
	s390/cio: cio_ignore_proc_seq_next should increase position index
	cifs: don't leak -EAGAIN for stat() during reconnect
	usb: storage: Add quirk for Samsung Fit flash
	usb: quirks: add NO_LPM quirk for Logitech Screen Share
	usb: core: hub: do error out if usb_autopm_get_interface() fails
	usb: core: port: do error out if usb_autopm_get_interface() fails
	vgacon: Fix a UAF in vgacon_invert_region
	fat: fix uninit-memory access for partial initialized inode
	vt: selection, close sel_buffer race
	vt: selection, push console lock down
	vt: selection, push sel_lock up
	dmaengine: tegra-apb: Fix use-after-free
	dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list
	ASoC: pcm: Fix possible buffer overflow in dpcm state sysfs output
	ASoC: pcm512x: Fix unbalanced regulator enable call in probe error path
	ASoC: dapm: Correct DAPM handling of active widgets during shutdown
	RDMA/iwcm: Fix iwcm work deallocation
	RMDA/cm: Fix missing ib_cm_destroy_id() in ib_cm_insert_listen()
	ARM: imx: build v7_cpu_resume() unconditionally
	hwmon: (adt7462) Fix an error return in ADT7462_REG_VOLT()
	dmaengine: coh901318: Fix a double lock bug in dma_tc_handle()
	powerpc: fix hardware PMU exception bug on PowerVM compatibility mode systems
	dm cache: fix a crash due to incorrect work item cancelling
	crypto: algif_skcipher - use ZERO_OR_NULL_PTR in skcipher_recvmsg_async
	Linux 4.4.216

Change-Id: I9b747fb2a39b1137ee4ec9c5bb2c1aac2419e97b
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

1 files changed, 49 insertions, 13 deletions

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 5223eb25bf59..f5b6667b0ab0 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -16,6 +16,33 @@
 
 #include "ext4_jbd2.h"
 
+struct ext4_rcu_ptr {
+	struct rcu_head rcu;
+	void *ptr;
+};
+
+static void ext4_rcu_ptr_callback(struct rcu_head *head)
+{
+	struct ext4_rcu_ptr *ptr;
+
+	ptr = container_of(head, struct ext4_rcu_ptr, rcu);
+	kvfree(ptr->ptr);
+	kfree(ptr);
+}
+
+void ext4_kvfree_array_rcu(void *to_free)
+{
+	struct ext4_rcu_ptr *ptr = kzalloc(sizeof(*ptr), GFP_KERNEL);
+
+	if (ptr) {
+		ptr->ptr = to_free;
+		call_rcu(&ptr->rcu, ext4_rcu_ptr_callback);
+		return;
+	}
+	synchronize_rcu();
+	kvfree(to_free);
+}
+
 int ext4_resize_begin(struct super_block *sb)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -541,8 +568,8 @@ static int setup_new_flex_group_blocks(struct super_block *sb,
 				brelse(gdb);
 				goto out;
 			}
-			memcpy(gdb->b_data, sbi->s_group_desc[j]->b_data,
-			       gdb->b_size);
+			memcpy(gdb->b_data, sbi_array_rcu_deref(sbi,
+				s_group_desc, j)->b_data, gdb->b_size);
 			set_buffer_uptodate(gdb);
 
 			err = ext4_handle_dirty_metadata(handle, NULL, gdb);
@@ -849,13 +876,15 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
 	}
 	brelse(dind);
 
-	o_group_desc = EXT4_SB(sb)->s_group_desc;
+	rcu_read_lock();
+	o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc);
 	memcpy(n_group_desc, o_group_desc,
 	       EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
+	rcu_read_unlock();
 	n_group_desc[gdb_num] = gdb_bh;
-	EXT4_SB(sb)->s_group_desc = n_group_desc;
+	rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc);
 	EXT4_SB(sb)->s_gdb_count++;
-	kvfree(o_group_desc);
+	ext4_kvfree_array_rcu(o_group_desc);
 
 	le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
 	err = ext4_handle_dirty_super(handle, sb);
@@ -903,9 +932,11 @@ static int add_new_gdb_meta_bg(struct super_block *sb,
 		return err;
 	}
 
-	o_group_desc = EXT4_SB(sb)->s_group_desc;
+	rcu_read_lock();
+	o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc);
 	memcpy(n_group_desc, o_group_desc,
 	       EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
+	rcu_read_unlock();
 	n_group_desc[gdb_num] = gdb_bh;
 
 	BUFFER_TRACE(gdb_bh, "get_write_access");
@@ -916,9 +947,9 @@ static int add_new_gdb_meta_bg(struct super_block *sb,
 		return err;
 	}
 
-	EXT4_SB(sb)->s_group_desc = n_group_desc;
+	rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc);
 	EXT4_SB(sb)->s_gdb_count++;
-	kvfree(o_group_desc);
+	ext4_kvfree_array_rcu(o_group_desc);
 	return err;
 }
 
@@ -1180,7 +1211,8 @@ static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
 		 * use non-sparse filesystems anymore.  This is already checked above.
 		 */
 		if (gdb_off) {
-			gdb_bh = sbi->s_group_desc[gdb_num];
+			gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc,
+						     gdb_num);
 			BUFFER_TRACE(gdb_bh, "get_write_access");
 			err = ext4_journal_get_write_access(handle, gdb_bh);
 
@@ -1262,7 +1294,7 @@ static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
 		/*
 		 * get_write_access() has been called on gdb_bh by ext4_add_new_desc().
 		 */
-		gdb_bh = sbi->s_group_desc[gdb_num];
+		gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, gdb_num);
 		/* Update group descriptor block for new group */
 		gdp = (struct ext4_group_desc *)(gdb_bh->b_data +
 						 gdb_off * EXT4_DESC_SIZE(sb));
@@ -1390,11 +1422,14 @@ static void ext4_update_super(struct super_block *sb,
 		   percpu_counter_read(&sbi->s_freeclusters_counter));
 	if (ext4_has_feature_flex_bg(sb) && sbi->s_log_groups_per_flex) {
 		ext4_group_t flex_group;
+		struct flex_groups *fg;
+
 		flex_group = ext4_flex_group(sbi, group_data[0].group);
+		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
 		atomic64_add(EXT4_NUM_B2C(sbi, free_blocks),
-			     &sbi->s_flex_groups[flex_group].free_clusters);
+			     &fg->free_clusters);
 		atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count,
-			   &sbi->s_flex_groups[flex_group].free_inodes);
+			   &fg->free_inodes);
 	}
 
 	/*
@@ -1489,7 +1524,8 @@ exit_journal:
 		for (; gdb_num <= gdb_num_end; gdb_num++) {
 			struct buffer_head *gdb_bh;
 
-			gdb_bh = sbi->s_group_desc[gdb_num];
+			gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc,
+						     gdb_num);
 			if (old_gdb == gdb_bh->b_blocknr)
 				continue;
 			update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,