Merge tag 'ext4-for-linus-5.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull more ext4 updates from Ted Ts'o:
 "This is the second round of ext4 commits for 5.8 merge window [1].

  It includes the per-inode DAX support, which was dependant on the DAX
  infrastructure which came in via the XFS tree, and a number of
  regression and bug fixes; most notably the "BUG: using
  smp_processor_id() in preemptible code in ext4_mb_new_blocks" reported
  by syzkaller"

[1] The pull request actually came in 15 minutes after I had tagged the
    rc1 release. Tssk, tssk, late..   - Linus

* tag 'ext4-for-linus-5.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4, jbd2: ensure panic by fix a race between jbd2 abort and ext4 error handlers
  ext4: support xattr gnu.* namespace for the Hurd
  ext4: mballoc: Use this_cpu_read instead of this_cpu_ptr
  ext4: avoid utf8_strncasecmp() with unstable name
  ext4: stop overwrite the errcode in ext4_setup_super
  ext4: fix partial cluster initialization when splitting extent
  ext4: avoid race conditions when remounting with options that change dax
  Documentation/dax: Update DAX enablement for ext4
  fs/ext4: Introduce DAX inode flag
  fs/ext4: Remove jflag variable
  fs/ext4: Make DAX mount option a tri-state
  fs/ext4: Only change S_DAX on inode load
  fs/ext4: Update ext4_should_use_dax()
  fs/ext4: Change EXT4_MOUNT_DAX to EXT4_MOUNT_DAX_ALWAYS
  fs/ext4: Disallow verity if inode is DAX
  fs/ext4: Narrow scope of DAX check in setflags

1 files changed, 12 insertions, 5 deletions

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index a49d0e670ddf..e4944436e733 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1140,6 +1140,7 @@ static journal_t *journal_init_common(struct block_device *bdev,
 	init_waitqueue_head(&journal->j_wait_commit);
 	init_waitqueue_head(&journal->j_wait_updates);
 	init_waitqueue_head(&journal->j_wait_reserved);
+	mutex_init(&journal->j_abort_mutex);
 	mutex_init(&journal->j_barrier);
 	mutex_init(&journal->j_checkpoint_mutex);
 	spin_lock_init(&journal->j_revoke_lock);
@@ -1402,7 +1403,8 @@ static int jbd2_write_superblock(journal_t *journal, int write_flags)
 		printk(KERN_ERR "JBD2: Error %d detected when updating "
 		       "journal superblock for %s.\n", ret,
 		       journal->j_devname);
-		jbd2_journal_abort(journal, ret);
+		if (!is_journal_aborted(journal))
+			jbd2_journal_abort(journal, ret);
 	}
 
 	return ret;
@@ -2154,6 +2156,13 @@ void jbd2_journal_abort(journal_t *journal, int errno)
 	transaction_t *transaction;
 
 	/*
+	 * Lock the aborting procedure until everything is done, this avoid
+	 * races between filesystem's error handling flow (e.g. ext4_abort()),
+	 * ensure panic after the error info is written into journal's
+	 * superblock.
+	 */
+	mutex_lock(&journal->j_abort_mutex);
+	/*
 	 * ESHUTDOWN always takes precedence because a file system check
 	 * caused by any other journal abort error is not required after
 	 * a shutdown triggered.
@@ -2167,6 +2176,7 @@ void jbd2_journal_abort(journal_t *journal, int errno)
 			journal->j_errno = errno;
 			jbd2_journal_update_sb_errno(journal);
 		}
+		mutex_unlock(&journal->j_abort_mutex);
 		return;
 	}
 
@@ -2188,10 +2198,7 @@ void jbd2_journal_abort(journal_t *journal, int errno)
 	 * layer could realise that a filesystem check is needed.
 	 */
 	jbd2_journal_update_sb_errno(journal);
-
-	write_lock(&journal->j_state_lock);
-	journal->j_flags |= JBD2_REC_ERR;
-	write_unlock(&journal->j_state_lock);
+	mutex_unlock(&journal->j_abort_mutex);
 }
 
 /**