diff options
| author | Jan Kara <jack@suse.cz> | 2012-06-12 16:20:38 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-07-31 07:45:48 +0200 |
| commit | 8e8ad8a57c75f3bda2d03a4c4396a9a7024ad275 (patch) | |
| tree | 8d1fd1d0f296d2a2977b54dee5740d855dfa031e /fs/ext4/mmp.c | |
| parent | fs: Protect write paths by sb_start_write - sb_end_write (diff) | |
| download | linux-8e8ad8a57c75f3bda2d03a4c4396a9a7024ad275.tar.xz linux-8e8ad8a57c75f3bda2d03a4c4396a9a7024ad275.zip | |
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" <tytso@mit.edu>
BugLink: https://bugs.launchpad.net/bugs/897421
Tested-by: Kamal Mostafa <kamal@canonical.com>
Tested-by: Peter M. Petrakis <peter.petrakis@canonical.com>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Tested-by: Massimo Morana <massimo.morana@canonical.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/ext4/mmp.c')
| -rw-r--r-- | fs/ext4/mmp.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index f99a1311e847..fe7c63f4717e 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; |