linux.git/fs/reiserfs, branch v3.6

reiserfs: fix deadlocks with quotas

2012-08-14T22:22:57+00:00

The BKL push-down for reiserfs made lock recursion a special case that needs
to be handled explicitly. One of the cases that was unhandled is dropping
the quota during inode eviction. Both reiserfs_evict_inode and
reiserfs_write_dquot take the write lock, but when the journal lock is
taken it only drops one the references. The locking rules are that the journal
lock be acquired before the write lock so leaving the reference open leads
to a ABBA deadlock.

This patch pushes the unlock up before clear_inode and avoids the recursive
locking.

Another ABBA situation can occur when the write lock is dropped while reading
the bitmap buffer while in the quota code. When the lock is reacquired, it
will deadlock against dquot->dq_lock and dqopt->dqio_mutex in the dquot_acquire
path. It's safe to retain the lock across the read and should be cached under
write load.

Signed-off-by: Jeff Mahoney 
Signed-off-by: Jan Kara

don't expose I_NEW inodes via dentry->d_inode

2012-07-22T20:00:58+00:00

	d_instantiate(dentry, inode);
	unlock_new_inode(inode);

is a bad idea; do it the other way round...

Signed-off-by: Al Viro

quota: Move quota syncing to ->sync_fs method

2012-07-22T19:58:34+00:00

Since the moment writes to quota files are using block device page cache and
space for quota structures is reserved at the moment they are first accessed we
have no reason to sync quota before inode writeback. In fact this order is now
only harmful since quota information can easily change during inode writeback
(either because conversion of delayed-allocated extents or simply because of
allocation of new blocks for simple filesystems not using page_mkwrite).

So move syncing of quota information after writeback of inodes into ->sync_fs
method. This way we do not have to use ->quota_sync callback which is primarily
intended for use by quotactl syscall anyway and we get rid of calling
->sync_fs() twice unnecessarily. We skip quota syncing for OCFS2 since it does
proper quota journalling in all cases (unlike ext3, ext4, and reiserfs which
also support legacy non-journalled quotas) and thus there are no dirty quota
structures.

CC: "Theodore Ts'o" 
CC: Joel Becker 
CC: reiserfs-devel@vger.kernel.org
Acked-by: Steven Whitehouse 
Acked-by: Dave Kleikamp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jan Kara 
Signed-off-by: Al Viro

VFS: Pass mount flags to sget()

2012-07-14T12:38:34+00:00

Pass mount flags to sget() so that it can use them in initialising a new
superblock before the set function is called.  They could also be passed to the
compare function.

Signed-off-by: David Howells 
Signed-off-by: Al Viro

don't pass nameidata to ->create()

2012-07-14T12:34:47+00:00

boolean "does it have to be exclusive?" flag is passed instead;
Local filesystem should just ignore it - the object is guaranteed
not to be there yet.

Signed-off-by: Al Viro

stop passing nameidata to ->lookup()

2012-07-14T12:34:32+00:00

Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument.  And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...

Signed-off-by: Al Viro

stop passing nameidata * to ->d_revalidate()

2012-07-14T12:34:14+00:00

Just the lookup flags.  Die, bastard, die...

Signed-off-by: Al Viro

reiserfs: get rid of resierfs_sync_super

2012-06-01T14:37:36+00:00

This patch stops reiserfs using the VFS 'write_super()' method along with the
s_dirt flag, because they are on their way out.

The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblock using the '->write_super()' call-back.  But the
problem with this thread is that it wastes power by waking up the system every
5 seconds, even if there are no diry superblocks, or there are no client
file-systems which would need this (e.g., btrfs does not use
'->write_super()'). So we want to kill it completely and thus, we need to make
file-systems to stop using the '->write_super()' VFS service, and then remove
it together with the kernel thread.

Signed-off-by: Artem Bityutskiy 
Signed-off-by: Al Viro

reiserfs: mark the superblock as dirty a bit later

2012-06-01T14:37:36+00:00

The 'journal_mark_dirty()' function currently first marks the superblock as
dirty by setting 's_dirt' to 1, then does various sanity checks and returns,
then actuall does all the magic with the journal.

This is not an ideal order, though. It makes more sense to first do all the
checks, then do all the internal stuff, and at the end notify the VFS that the
superblock is now dirty.

This patch moves the 's_dirt = 1' assignment from the very beginning of this
function to the very end.

Signed-off-by: Artem Bityutskiy 
Signed-off-by: Al Viro

reiserfs: remove useless superblock dirtying

2012-06-01T14:37:36+00:00

The 'reiserfs_resize()' function marks the superblock as dirty by assigning 1
to 's_dirt' and then calls 'journal_mark_dirty()' which does the same. Thus,
we can remove the assignment from 'reiserfs_resize()'.

Signed-off-by: Artem Bityutskiy 
Signed-off-by: Al Viro