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From: Theodore Ts'o <tytso@mit.edu>
To: stable@vger.kernel.org
Cc: Ext4 Developers List <linux-ext4@vger.kernel.org>,
	Eric Sandeen <sandeen@redhat.com>,
	"Theodore Ts'o" <tytso@mit.edu>
Subject: [PATCH 2.6.33.y 24/40] ext4: don't return to userspace after freezing the fs with a mutex held
Date: Tue,  1 Jun 2010 08:03:11 -0400	[thread overview]
Message-ID: <1275393807-14369-24-git-send-email-tytso@mit.edu> (raw)
In-Reply-To: <1275393807-14369-1-git-send-email-tytso@mit.edu>

From: Eric Sandeen <sandeen@redhat.com>

commit 6b0310fbf087ad6e9e3b8392adca97cd77184084 upstream (as of v2.6.34-git13)

ext4_freeze() used jbd2_journal_lock_updates() which takes
the j_barrier mutex, and then returns to userspace.  The
kernel does not like this:

================================================
[ BUG: lock held when returning to user space! ]
------------------------------------------------
lvcreate/1075 is leaving the kernel with locks still held!
1 lock held by lvcreate/1075:
 #0:  (&journal->j_barrier){+.+...}, at: [<ffffffff811c6214>]
jbd2_journal_lock_updates+0xe1/0xf0

Use vfs_check_frozen() added to ext4_journal_start_sb() and
ext4_force_commit() instead.

Addresses-Red-Hat-Bugzilla: #568503

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
 fs/ext4/super.c |   20 ++++++++++----------
 1 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 735c20d..a6a8e5b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -227,6 +227,7 @@ handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 	if (sb->s_flags & MS_RDONLY)
 		return ERR_PTR(-EROFS);
 
+	vfs_check_frozen(sb, SB_FREEZE_WRITE);
 	/* Special case here: if the journal has aborted behind our
 	 * backs (eg. EIO in the commit thread), then we still need to
 	 * take the FS itself readonly cleanly. */
@@ -3386,8 +3387,10 @@ int ext4_force_commit(struct super_block *sb)
 		return 0;
 
 	journal = EXT4_SB(sb)->s_journal;
-	if (journal)
+	if (journal) {
+		vfs_check_frozen(sb, SB_FREEZE_WRITE);
 		ret = ext4_journal_force_commit(journal);
+	}
 
 	return ret;
 }
@@ -3436,18 +3439,16 @@ static int ext4_freeze(struct super_block *sb)
 	 * the journal.
 	 */
 	error = jbd2_journal_flush(journal);
-	if (error < 0) {
-	out:
-		jbd2_journal_unlock_updates(journal);
-		return error;
-	}
+	if (error < 0)
+		goto out;
 
 	/* Journal blocked and flushed, clear needs_recovery flag. */
 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 	error = ext4_commit_super(sb, 1);
-	if (error)
-		goto out;
-	return 0;
+out:
+	/* we rely on s_frozen to stop further updates */
+	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
+	return error;
 }
 
 /*
@@ -3464,7 +3465,6 @@ static int ext4_unfreeze(struct super_block *sb)
 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 	ext4_commit_super(sb, 1);
 	unlock_super(sb);
-	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 	return 0;
 }
 
-- 
1.6.6.1.1.g974db.dirty


  parent reply	other threads:[~2010-06-01 12:03 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-01 12:02 [PATCH 2.6.33.y 01/40] ext4: Use bitops to read/modify EXT4_I(inode)->i_state Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 02/40] ext4: Fix BUG_ON at fs/buffer.c:652 in no journal mode Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 03/40] ext4: Add flag to files with blocks intentionally past EOF Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 04/40] ext4: Fix fencepost error in chosing choosing group vs file preallocation Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 05/40] ext4: fix error handling in migrate Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 06/40] ext4: explicitly remove inode from orphan list after failed direct io Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 07/40] ext4: Handle non empty on-disk orphan link Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 08/40] ext4: make "offset" consistent in ext4_check_dir_entry() Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 09/40] ext4: Fix insertion point of extent in mext_insert_across_blocks() Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 10/40] ext4: Fix the NULL reference in double_down_write_data_sem() Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 11/40] ext4: Code cleanup for EXT4_IOC_MOVE_EXT ioctl Theodore Ts'o
2010-06-01 12:02 ` [PATCH 2.6.33.y 12/40] ext4: Fix estimate of # of blocks needed to write indirect-mapped files Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 13/40] ext4: Fixed inode allocator to correctly track a flex_bg's used_dirs Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 14/40] ext4: Fix possible lost inode write in no journal mode Theodore Ts'o
2012-09-28  3:08   ` Yongqiang Yang
2012-09-28  3:21     ` Yongqiang Yang
2010-06-01 12:03 ` [PATCH 2.6.33.y 15/40] ext4: Fix buffer head leaks after calls to ext4_get_inode_loc() Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 16/40] ext4: Issue the discard operation *before* releasing the blocks to be reused Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 17/40] ext4: check missed return value in ext4_sync_file() Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 18/40] ext4: fix memory leaks in error path handling of ext4_ext_zeroout() Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 19/40] ext4: Remove unnecessary call to ext4_get_group_desc() in mballoc Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 20/40] ext4: rename ext4_mb_release_desc() to ext4_mb_unload_buddy() Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 21/40] ext4: allow defrag (EXT4_IOC_MOVE_EXT) in 32bit compat mode Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 22/40] ext4: fix quota accounting in case of fallocate Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 23/40] ext4: check s_log_groups_per_flex in online resize code Theodore Ts'o
2010-06-01 12:03 ` Theodore Ts'o [this message]
2010-06-01 12:03 ` [PATCH 2.6.33.y 25/40] ext4: stop issuing discards if not supported by device Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 26/40] ext4: don't scan/accumulate more pages than mballoc will allocate Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 27/40] ext4: Do not zero out uninitialized extents beyond i_size Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 28/40] ext4: clean up inode bitmaps manipulation in ext4_free_inode Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 29/40] ext4: init statistics after journal recovery Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 30/40] ext4: Remove extraneous newlines in ext4_msg() calls Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 31/40] ext4: Prevent creation of files larger than RLIMIT_FSIZE using fallocate Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 32/40] ext4: check for a good block group before loading buddy pages Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 33/40] ext4: Show journal_checksum option Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 34/40] ext4: Use bitops to read/modify i_flags in struct ext4_inode_info Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 35/40] ext4: Avoid crashing on NULL ptr dereference on a filesystem error Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 36/40] ext4: Clear the EXT4_EOFBLOCKS_FL flag only when warranted Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 37/40] ext4: restart ext4_ext_remove_space() after transaction restart Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 38/40] ext4: Conditionally define compat ioctl numbers Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 39/40] ext4: Fix compat EXT4_IOC_ADD_GROUP Theodore Ts'o
2010-06-01 12:03 ` [PATCH 2.6.33.y 40/40] ext4: Make fsync sync new parent directories in no-journal mode Theodore Ts'o
2010-07-28 23:29 ` [stable] [PATCH 2.6.33.y 01/40] ext4: Use bitops to read/modify EXT4_I(inode)->i_state Greg KH

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