From 61c219f5814277ecb71d64cb30297028d6665979 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Sat, 5 Jul 2014 16:28:35 -0400
Subject: ext4: fix unjournalled bg descriptor while initializing inode bitmap

The first time that we allocate from an uninitialized inode allocation
bitmap, if the block allocation bitmap is also uninitalized, we need
to get write access to the block group descriptor before we start
modifying the block group descriptor flags and updating the free block
count, etc.  Otherwise, there is the potential of a bad journal
checksum (if journal checksums are enabled), and of the file system
becoming inconsistent if we crash at exactly the wrong time.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
---
 fs/ext4/ialloc.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index a87455df38b..0840bf321cd 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -874,6 +874,13 @@ got:
 		goto out;
 	}
 
+	BUFFER_TRACE(group_desc_bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, group_desc_bh);
+	if (err) {
+		ext4_std_error(sb, err);
+		goto out;
+	}
+
 	/* We may have to initialize the block bitmap if it isn't already */
 	if (ext4_has_group_desc_csum(sb) &&
 	    gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
@@ -910,13 +917,6 @@ got:
 		}
 	}
 
-	BUFFER_TRACE(group_desc_bh, "get_write_access");
-	err = ext4_journal_get_write_access(handle, group_desc_bh);
-	if (err) {
-		ext4_std_error(sb, err);
-		goto out;
-	}
-
 	/* Update the relevant bg descriptor fields */
 	if (ext4_has_group_desc_csum(sb)) {
 		int free;
-- 
cgit v1.2.3-18-g5258


From ae0f78de2c43b6fadd007c231a352b13b5be8ed2 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Sat, 5 Jul 2014 18:40:52 -0400
Subject: ext4: clarify error count warning messages

Make it clear that values printed are times, and that it is error
since last fsck. Also add note about fsck version required.

Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Cc: stable@vger.kernel.org
---
 fs/ext4/super.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b9b9aabfb4d..342394772b6 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2809,10 +2809,11 @@ static void print_daily_error_info(unsigned long arg)
 	es = sbi->s_es;
 
 	if (es->s_error_count)
-		ext4_msg(sb, KERN_NOTICE, "error count: %u",
+		/* fsck newer than v1.41.13 is needed to clean this condition. */
+		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
 			 le32_to_cpu(es->s_error_count));
 	if (es->s_first_error_time) {
-		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
+		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
 		       (int) sizeof(es->s_first_error_func),
 		       es->s_first_error_func,
@@ -2826,7 +2827,7 @@ static void print_daily_error_info(unsigned long arg)
 		printk("\n");
 	}
 	if (es->s_last_error_time) {
-		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
+		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
 		       (int) sizeof(es->s_last_error_func),
 		       es->s_last_error_func,
-- 
cgit v1.2.3-18-g5258


From 94d4c066a4ff170a2671b1a9b153febbf36796f6 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Sat, 5 Jul 2014 19:15:50 -0400
Subject: ext4: clarify ext4_error message in ext4_mb_generate_buddy_error()

We are spending a lot of time explaining to users what this error
means.  Let's try to improve the message to avoid this problem.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
---
 fs/ext4/mballoc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 7f72f50a8fa..2dcb936be90 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -752,8 +752,8 @@ void ext4_mb_generate_buddy(struct super_block *sb,
 
 	if (free != grp->bb_free) {
 		ext4_grp_locked_error(sb, group, 0, 0,
-				      "%u clusters in bitmap, %u in gd; "
-				      "block bitmap corrupt.",
+				      "block bitmap and bg descriptor "
+				      "inconsistent: %u vs %u free clusters",
 				      free, grp->bb_free);
 		/*
 		 * If we intend to continue, we consider group descriptor
-- 
cgit v1.2.3-18-g5258


From 5dd214248f94d430d70e9230bda72f2654ac88a8 Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen@redhat.com>
Date: Sat, 5 Jul 2014 19:18:22 -0400
Subject: ext4: disable synchronous transaction batching if max_batch_time==0

The mount manpage says of the max_batch_time option,

	This optimization can be turned off entirely
	by setting max_batch_time to 0.

But the code doesn't do that.  So fix the code to do
that.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
---
 fs/ext4/super.c       | 2 --
 fs/jbd2/transaction.c | 5 ++++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 342394772b6..6297c07c937 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1525,8 +1525,6 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
 		sbi->s_commit_interval = HZ * arg;
 	} else if (token == Opt_max_batch_time) {
-		if (arg == 0)
-			arg = EXT4_DEF_MAX_BATCH_TIME;
 		sbi->s_max_batch_time = arg;
 	} else if (token == Opt_min_batch_time) {
 		sbi->s_min_batch_time = arg;
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 38cfcf5f6fc..6f0f590cc5a 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1588,9 +1588,12 @@ int jbd2_journal_stop(handle_t *handle)
 	 * to perform a synchronous write.  We do this to detect the
 	 * case where a single process is doing a stream of sync
 	 * writes.  No point in waiting for joiners in that case.
+	 *
+	 * Setting max_batch_time to 0 disables this completely.
 	 */
 	pid = current->pid;
-	if (handle->h_sync && journal->j_last_sync_writer != pid) {
+	if (handle->h_sync && journal->j_last_sync_writer != pid &&
+	    journal->j_max_batch_time) {
 		u64 commit_time, trans_time;
 
 		journal->j_last_sync_writer = pid;
-- 
cgit v1.2.3-18-g5258


From f9ae9cf5d72b3926ca48ea60e15bdbb840f42372 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Fri, 11 Jul 2014 13:55:40 -0400
Subject: ext4: revert commit which was causing fs corruption after journal
 replays

Commit 007649375f6af2 ("ext4: initialize multi-block allocator before
checking block descriptors") causes the block group descriptor's count
of the number of free blocks to become inconsistent with the number of
free blocks in the allocation bitmap.  This is a harmless form of fs
corruption, but it causes the kernel to potentially remount the file
system read-only, or to panic, depending on the file systems's error
behavior.

Thanks to Eric Whitney for his tireless work to reproduce and to find
the guilty commit.

Fixes: 007649375f6af2 ("ext4: initialize multi-block allocator before checking block descriptors"

Cc: stable@vger.kernel.org  # 3.15
Reported-by: David Jander <david@protonic.nl>
Reported-by: Matteo Croce <technoboy85@gmail.com>
Tested-by: Eric Whitney <enwlinux@gmail.com>
Suggested-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
 fs/ext4/super.c | 51 ++++++++++++++++++++++++---------------------------
 1 file changed, 24 insertions(+), 27 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 6297c07c937..6df7bc611db 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3879,38 +3879,19 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 			goto failed_mount2;
 		}
 	}
-
-	/*
-	 * set up enough so that it can read an inode,
-	 * and create new inode for buddy allocator
-	 */
-	sbi->s_gdb_count = db_count;
-	if (!test_opt(sb, NOLOAD) &&
-	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
-		sb->s_op = &ext4_sops;
-	else
-		sb->s_op = &ext4_nojournal_sops;
-
-	ext4_ext_init(sb);
-	err = ext4_mb_init(sb);
-	if (err) {
-		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
-			 err);
-		goto failed_mount2;
-	}
-
 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
-		goto failed_mount2a;
+		goto failed_mount2;
 	}
 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
 		if (!ext4_fill_flex_info(sb)) {
 			ext4_msg(sb, KERN_ERR,
 			       "unable to initialize "
 			       "flex_bg meta info!");
-			goto failed_mount2a;
+			goto failed_mount2;
 		}
 
+	sbi->s_gdb_count = db_count;
 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 	spin_lock_init(&sbi->s_next_gen_lock);
 
@@ -3945,6 +3926,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sbi->s_stripe = ext4_get_stripe_size(sbi);
 	sbi->s_extent_max_zeroout_kb = 32;
 
+	/*
+	 * set up enough so that it can read an inode
+	 */
+	if (!test_opt(sb, NOLOAD) &&
+	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
+		sb->s_op = &ext4_sops;
+	else
+		sb->s_op = &ext4_nojournal_sops;
 	sb->s_export_op = &ext4_export_ops;
 	sb->s_xattr = ext4_xattr_handlers;
 #ifdef CONFIG_QUOTA
@@ -4134,13 +4123,21 @@ no_journal:
 	if (err) {
 		ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
 			 "reserved pool", ext4_calculate_resv_clusters(sb));
-		goto failed_mount5;
+		goto failed_mount4a;
 	}
 
 	err = ext4_setup_system_zone(sb);
 	if (err) {
 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
 			 "zone (%d)", err);
+		goto failed_mount4a;
+	}
+
+	ext4_ext_init(sb);
+	err = ext4_mb_init(sb);
+	if (err) {
+		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
+			 err);
 		goto failed_mount5;
 	}
 
@@ -4217,8 +4214,11 @@ failed_mount8:
 failed_mount7:
 	ext4_unregister_li_request(sb);
 failed_mount6:
-	ext4_release_system_zone(sb);
+	ext4_mb_release(sb);
 failed_mount5:
+	ext4_ext_release(sb);
+	ext4_release_system_zone(sb);
+failed_mount4a:
 	dput(sb->s_root);
 	sb->s_root = NULL;
 failed_mount4:
@@ -4242,14 +4242,11 @@ failed_mount3:
 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
 	if (sbi->s_mmp_tsk)
 		kthread_stop(sbi->s_mmp_tsk);
-failed_mount2a:
-	ext4_mb_release(sb);
 failed_mount2:
 	for (i = 0; i < db_count; i++)
 		brelse(sbi->s_group_desc[i]);
 	ext4_kvfree(sbi->s_group_desc);
 failed_mount:
-	ext4_ext_release(sb);
 	if (sbi->s_chksum_driver)
 		crypto_free_shash(sbi->s_chksum_driver);
 	if (sbi->s_proc) {
-- 
cgit v1.2.3-18-g5258


From 3f1f9b851311a76226140b55b1ea22111234a7c2 Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Sat, 12 Jul 2014 15:32:24 -0400
Subject: ext4: fix a potential deadlock in __ext4_es_shrink()

This fixes the following lockdep complaint:

[ INFO: possible circular locking dependency detected ]
3.16.0-rc2-mm1+ #7 Tainted: G           O
-------------------------------------------------------
kworker/u24:0/4356 is trying to acquire lock:
 (&(&sbi->s_es_lru_lock)->rlock){+.+.-.}, at: [<ffffffff81285fff>] __ext4_es_shrink+0x4f/0x2e0

but task is already holding lock:
 (&ei->i_es_lock){++++-.}, at: [<ffffffff81286961>] ext4_es_insert_extent+0x71/0x180

which lock already depends on the new lock.

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_es_lock);
                               lock(&(&sbi->s_es_lru_lock)->rlock);
                               lock(&ei->i_es_lock);
  lock(&(&sbi->s_es_lru_lock)->rlock);

 *** DEADLOCK ***

6 locks held by kworker/u24:0/4356:
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff81071d00>] process_one_work+0x180/0x560
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff81071d00>] process_one_work+0x180/0x560
 #2:  (&type->s_umount_key#22){++++++}, at: [<ffffffff811a9c74>] grab_super_passive+0x44/0x90
 #3:  (jbd2_handle){+.+...}, at: [<ffffffff812979f9>] start_this_handle+0x189/0x5f0
 #4:  (&ei->i_data_sem){++++..}, at: [<ffffffff81247062>] ext4_map_blocks+0x132/0x550
 #5:  (&ei->i_es_lock){++++-.}, at: [<ffffffff81286961>] ext4_es_insert_extent+0x71/0x180

stack backtrace:
CPU: 0 PID: 4356 Comm: kworker/u24:0 Tainted: G           O   3.16.0-rc2-mm1+ #7
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Workqueue: writeback bdi_writeback_workfn (flush-253:0)
 ffffffff8213dce0 ffff880014b07538 ffffffff815df0bb 0000000000000007
 ffffffff8213e040 ffff880014b07588 ffffffff815db3dd ffff880014b07568
 ffff880014b07610 ffff88003b868930 ffff88003b868908 ffff88003b868930
Call Trace:
 [<ffffffff815df0bb>] dump_stack+0x4e/0x68
 [<ffffffff815db3dd>] print_circular_bug+0x1fb/0x20c
 [<ffffffff810a7a3e>] __lock_acquire+0x163e/0x1d00
 [<ffffffff815e89dc>] ? retint_restore_args+0xe/0xe
 [<ffffffff815ddc7b>] ? __slab_alloc+0x4a8/0x4ce
 [<ffffffff81285fff>] ? __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff810a8707>] lock_acquire+0x87/0x120
 [<ffffffff81285fff>] ? __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff8128592d>] ? ext4_es_free_extent+0x5d/0x70
 [<ffffffff815e6f09>] _raw_spin_lock+0x39/0x50
 [<ffffffff81285fff>] ? __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff8119760b>] ? kmem_cache_alloc+0x18b/0x1a0
 [<ffffffff81285fff>] __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff812869b8>] ext4_es_insert_extent+0xc8/0x180
 [<ffffffff812470f4>] ext4_map_blocks+0x1c4/0x550
 [<ffffffff8124c4c4>] ext4_writepages+0x6d4/0xd00
	...

Reported-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: Minchan Kim <minchan@kernel.org>
Cc: stable@vger.kernel.org
Cc: Zheng Liu <gnehzuil.liu@gmail.com>
---
 fs/ext4/extents_status.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 3f5c188953a..0b7e28e7eaa 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -966,10 +966,10 @@ retry:
 			continue;
 		}
 
-		if (ei->i_es_lru_nr == 0 || ei == locked_ei)
+		if (ei->i_es_lru_nr == 0 || ei == locked_ei ||
+		    !write_trylock(&ei->i_es_lock))
 			continue;
 
-		write_lock(&ei->i_es_lock);
 		shrunk = __es_try_to_reclaim_extents(ei, nr_to_scan);
 		if (ei->i_es_lru_nr == 0)
 			list_del_init(&ei->i_es_lru);
-- 
cgit v1.2.3-18-g5258


From bf40c92635d63fcc574c52649f7cda13e0418ac1 Mon Sep 17 00:00:00 2001
From: Namjae Jeon <namjae.jeon@samsung.com>
Date: Sat, 12 Jul 2014 16:11:42 -0400
Subject: ext4: fix potential null pointer dereference in ext4_free_inode

Fix potential null pointer dereferencing problem caused by e43bb4e612
("ext4: decrement free clusters/inodes counters when block group declared bad")

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
---
 fs/ext4/ialloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 0840bf321cd..5b87fc36aab 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -338,7 +338,7 @@ out:
 			fatal = err;
 	} else {
 		ext4_error(sb, "bit already cleared for inode %lu", ino);
-		if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
+		if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) {
 			int count;
 			count = ext4_free_inodes_count(sb, gdp);
 			percpu_counter_sub(&sbi->s_freeinodes_counter,
-- 
cgit v1.2.3-18-g5258