From 8e8ad8a57c75f3bda2d03a4c4396a9a7024ad275 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 12 Jun 2012 16:20:38 +0200 Subject: ext4: Convert to new freezing mechanism We remove most of frozen checks since upper layer takes care of blocking all writes. We have to handle protection in ext4_page_mkwrite() in a special way because we cannot use generic block_page_mkwrite(). Also we add a freeze protection to ext4_evict_inode() so that iput() of unlinked inode cannot modify a frozen filesystem (we cannot easily instrument ext4_journal_start() / ext4_journal_stop() with freeze protection because we are missing the superblock pointer in ext4_journal_stop() in nojournal mode). CC: linux-ext4@vger.kernel.org CC: "Theodore Ts'o" BugLink: https://bugs.launchpad.net/bugs/897421 Tested-by: Kamal Mostafa Tested-by: Peter M. Petrakis Tested-by: Dann Frazier Tested-by: Massimo Morana Acked-by: "Theodore Ts'o" Signed-off-by: Jan Kara Signed-off-by: Al Viro --- fs/ext4/mmp.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs/ext4/mmp.c') diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index f99a1311e84..fe7c63f4717 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -44,6 +44,11 @@ static int write_mmp_block(struct super_block *sb, struct buffer_head *bh) { struct mmp_struct *mmp = (struct mmp_struct *)(bh->b_data); + /* + * We protect against freezing so that we don't create dirty buffers + * on frozen filesystem. + */ + sb_start_write(sb); ext4_mmp_csum_set(sb, mmp); mark_buffer_dirty(bh); lock_buffer(bh); @@ -51,6 +56,7 @@ static int write_mmp_block(struct super_block *sb, struct buffer_head *bh) get_bh(bh); submit_bh(WRITE_SYNC, bh); wait_on_buffer(bh); + sb_end_write(sb); if (unlikely(!buffer_uptodate(bh))) return 1; -- cgit v1.2.3