Merge commit 'c104f1fa1ecf4ee0fc06e31b1f77630b2551be81' into stable/for-linus-3.4

* commit 'c104f1fa1ecf4ee0fc06e31b1f77630b2551be81': (14566 commits)
  cpufreq: OMAP: fix build errors: depends on ARCH_OMAP2PLUS
  sparc64: Eliminate obsolete __handle_softirq() function
  sparc64: Fix bootup crash on sun4v.
  kconfig: delete last traces of __enabled_ from autoconf.h
  Revert "kconfig: fix __enabled_ macros definition for invisible and un-selected symbols"
  kconfig: fix IS_ENABLED to not require all options to be defined
  irq_domain: fix type mismatch in debugfs output format
  staging: android: fix mem leaks in __persistent_ram_init()
  staging: vt6656: Don't leak memory in drivers/staging/vt6656/ioctl.c::private_ioctl()
  staging: iio: hmc5843: Fix crash in probe function.
  panic: fix stack dump print on direct call to panic()
  drivers/rtc/rtc-pl031.c: enable clock on all ST variants
  Revert "mm: vmscan: fix misused nr_reclaimed in shrink_mem_cgroup_zone()"
  hugetlb: fix race condition in hugetlb_fault()
  drivers/rtc/rtc-twl.c: use static register while reading time
  drivers/rtc/rtc-s3c.c: add placeholder for driver private data
  drivers/rtc/rtc-s3c.c: fix compilation error
  MAINTAINERS: add PCDP console maintainer
  memcg: do not open code accesses to res_counter members
  drivers/rtc/rtc-efi.c: fix section mismatch warning
  ...

1 files changed, 47 insertions, 5 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 5069b847515..806525a7269 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -28,7 +28,6 @@
 #include <linux/blkdev.h>
 #include <linux/bitops.h>
 #include <trace/events/jbd2.h>
-#include <asm/system.h>
 
 /*
  * Default IO end handler for temporary BJ_IO buffer_heads.
@@ -286,10 +285,10 @@ static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
 	char *addr;
 	__u32 checksum;
 
-	addr = kmap_atomic(page, KM_USER0);
+	addr = kmap_atomic(page);
 	checksum = crc32_be(crc32_sum,
 		(void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
-	kunmap_atomic(addr, KM_USER0);
+	kunmap_atomic(addr);
 
 	return checksum;
 }
@@ -331,6 +330,10 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	struct buffer_head *cbh = NULL; /* For transactional checksums */
 	__u32 crc32_sum = ~0;
 	struct blk_plug plug;
+	/* Tail of the journal */
+	unsigned long first_block;
+	tid_t first_tid;
+	int update_tail;
 
 	/*
 	 * First job: lock down the current transaction and wait for
@@ -340,7 +343,18 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	/* Do we need to erase the effects of a prior jbd2_journal_flush? */
 	if (journal->j_flags & JBD2_FLUSHED) {
 		jbd_debug(3, "super block updated\n");
-		jbd2_journal_update_superblock(journal, 1);
+		mutex_lock(&journal->j_checkpoint_mutex);
+		/*
+		 * We hold j_checkpoint_mutex so tail cannot change under us.
+		 * We don't need any special data guarantees for writing sb
+		 * since journal is empty and it is ok for write to be
+		 * flushed only with transaction commit.
+		 */
+		jbd2_journal_update_sb_log_tail(journal,
+						journal->j_tail_sequence,
+						journal->j_tail,
+						WRITE_SYNC);
+		mutex_unlock(&journal->j_checkpoint_mutex);
 	} else {
 		jbd_debug(3, "superblock not updated\n");
 	}
@@ -677,10 +691,30 @@ start_journal_io:
 		err = 0;
 	}
 
+	/*
+	 * Get current oldest transaction in the log before we issue flush
+	 * to the filesystem device. After the flush we can be sure that
+	 * blocks of all older transactions are checkpointed to persistent
+	 * storage and we will be safe to update journal start in the
+	 * superblock with the numbers we get here.
+	 */
+	update_tail =
+		jbd2_journal_get_log_tail(journal, &first_tid, &first_block);
+
 	write_lock(&journal->j_state_lock);
+	if (update_tail) {
+		long freed = first_block - journal->j_tail;
+
+		if (first_block < journal->j_tail)
+			freed += journal->j_last - journal->j_first;
+		/* Update tail only if we free significant amount of space */
+		if (freed < journal->j_maxlen / 4)
+			update_tail = 0;
+	}
 	J_ASSERT(commit_transaction->t_state == T_COMMIT);
 	commit_transaction->t_state = T_COMMIT_DFLUSH;
 	write_unlock(&journal->j_state_lock);
+
 	/* 
 	 * If the journal is not located on the file system device,
 	 * then we must flush the file system device before we issue
@@ -831,6 +865,14 @@ wait_for_iobuf:
 	if (err)
 		jbd2_journal_abort(journal, err);
 
+	/*
+	 * Now disk caches for filesystem device are flushed so we are safe to
+	 * erase checkpointed transactions from the log by updating journal
+	 * superblock.
+	 */
+	if (update_tail)
+		jbd2_update_log_tail(journal, first_tid, first_block);
+
 	/* End of a transaction!  Finally, we can do checkpoint
            processing: any buffers committed as a result of this
            transaction can be removed from any checkpoint list it was on
@@ -1048,7 +1090,7 @@ restart_loop:
 	jbd_debug(1, "JBD2: commit %d complete, head %d\n",
 		  journal->j_commit_sequence, journal->j_tail_sequence);
 	if (to_free)
-		kfree(commit_transaction);
+		jbd2_journal_free_transaction(commit_transaction);
 
 	wake_up(&journal->j_wait_done_commit);
 }