Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The entries in xattr handler table should be immutable (ie const)
like other operation tables.

Later patches convert common filesystems. Uncoverted filesystems
will still work, but will generate a compiler warning.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Currently the way we do freezing is by passing sb>s_bdev to freeze_bdev and then
letting it do all the work.  But freezing is more of an fs thing, and doesn't
really have much to do with the bdev at all, all the work gets done with the
super.  In btrfs we do not populate s_bdev, since we can have multiple bdev's
for one fs and setting s_bdev makes removing devices from a pool kind of tricky.
This means that freezing a btrfs filesystem fails, which causes us to corrupt
with things like tux-on-ice which use the fsfreeze mechanism.  So instead of
populating sb->s_bdev with a random bdev in our pool, I've broken the actual fs
freezing stuff into freeze_super and thaw_super.  These just take the
super_block that we're freezing and does the appropriate work.  It's basically
just copy and pasted from freeze_bdev.  I've then converted freeze_bdev over to
use the new super helpers.  I've tested this with ext4 and btrfs and verified
everything continues to work the same as before.

The only new gotcha is multiple calls to the fsfreeze ioctl will return EBUSY if
the fs is already frozen.  I thought this was a better solution than adding a
freeze counter to the super_block, but if everybody hates this idea I'm open to
suggestions.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and switch the simple "loop over superblocks and do something"
loops to it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and get rid of the last __put_super_and_need_restart() caller
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If superblock had been still alive, we would've returned it...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This one needs restarts...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

need list_for_each_entry_safe() here.  Original didn't even
have restart logics, so if you race with umount() it blew up.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

At the same time we can kill s_need_restart and local mutex in there.
__put_super() made public for a while; will be gone later.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We used to remove from s_list and s_instances at the same
time.  So let's *not* do the former and skip superblocks
that have empty s_instances in the loops over s_list.

The next step, of course, will be to get rid of rescan logics
in those loops.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Make sure that s_umount is acquired *before* we drop the final
active reference; we still have the fast path (atomic_dec_unless)
and we have gotten rid of the window between the moment when
s_active hits zero and s_umount is acquired.  Which simplifies
the living hell out of grab_super() and inotify pin_to_kill()
stuff.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

use atomic_inc_not_zero(&sb->s_active) instead of playing games with
checking ->s_count > S_BIAS
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

First of all, get_sb_nodev() grabs anon dev minor and we
never free it in ecryptfs ->kill_sb().  Moreover, on one
of the failure exits in ecryptfs_get_sb() we leak things -
it happens before we set ->s_root and ->put_super() won't
be called in that case.  Solution: kill ->put_super(), do
all that stuff in ->kill_sb().  And use kill_anon_sb() instead
of generic_shutdown_super() to deal with anon dev leak.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

postpone simple_set_mnt() until we know we won't fail.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We set the "it's dead, don't mount on it" flag _and_ do not remove it if
we turn the damn thing negative and leave it around.  And if it goes
positive afterwards, well...

Fortunately, there's only one place where that needs to be caught:
only d_delete() can turn the sucker negative without immediately freeing
it; all other places that can lead to ->d_iput() call are followed by
unconditionally freeing struct dentry in question.  So the fix is obvious:

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16014Reported-by: NAdam Tkac <vonsch@gmail.com>
Tested-by: NAdam Tkac <vonsch@gmail.com>
Cc: <stable@kernel.org>         [2.6.34.x]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

dquot: Detect partial write error to quota file in write_blk() and add printk_ratelimit for quota error messages

This patch changes quota_tree.c:write_blk() to detect error caused by partial
write to quota file and add a macro to limit control printed quota error
messages so we won't fill up dmesg with a corrupted quota file.
Signed-off-by: NJiaying Zhang <jiayingz@google.com>
Signed-off-by: NJan Kara <jack@suse.cz>

We cannot cancel delayed work from ocfs2_local_free_info because that is called
with dqonoff_mutex held and the work it cancels requires dqonoff_mutex to
finish. Cancel the work before acquiring dqonoff_mutex.
Acked-by: NJoel Becker <Joel.Becker@oracle.com>
Signed-off-by: NJan Kara <jack@suse.cz>

dquot_transfer() acquires own references to dquots via dqget(). Thus it waits
for dq_lock which creates a lock inversion because dq_lock ranks above
transaction start but transaction is already started in ocfs2_setattr(). Fix
the problem by passing own references directly to __dquot_transfer.
Acked-by: NJoel Becker <Joel.Becker@oracle.com>
Signed-off-by: NJan Kara <jack@suse.cz>

commit_dqblk() can write quota info to global file. That is actually a bad
thing to do because if we are just modifying local quota file, we are not
prepared (do not hold proper locks, do not have transaction credits) to do
a modification of the global quota file. So do not use commit_dqblk() and
instead call our writing function directly.
Acked-by: NJoel Becker <Joel.Becker@oracle.com>
Signed-off-by: NJan Kara <jack@suse.cz>

We were missing reservation of a journal credit for modification of quota
file inode when creating new dquot structure in the global quota file.
Acked-by: NJoel Becker <Joel.Becker@oracle.com>
Signed-off-by: NJan Kara <jack@suse.cz>

OCFS2 had three issues with quota locking:
a) When reading dquot from global quota file, we started a transaction while
   holding dqio_mutex which is prone to deadlocks because other paths do it
   the other way around
b) During ocfs2_sync_dquot we were not protected against concurrent writers
   on the same node. Because we first copy data to local buffer, a race
   could happen resulting in old data being written to global quota file and
   thus causing quota inconsistency after a crash.
c) ip_alloc_sem of quota files was acquired while a transaction is started
   in ocfs2_quota_write which can deadlock because we first get ip_alloc_sem
   and then start a transaction when extending quota files.

We fix the problem a) by pulling all necessary code to ocfs2_acquire_dquot
and ocfs2_release_dquot. Thus we no longer depend on generic dquot_acquire
to do the locking and can force proper lock ordering.

Problems b) and c) are fixed by locking i_mutex and ip_alloc_sem of
global quota file in ocfs2_lock_global_qf and removing ip_alloc_sem from
ocfs2_quota_read and ocfs2_quota_write.
Acked-by: NJoel Becker <Joel.Becker@oracle.com>
Signed-off-by: NJan Kara <jack@suse.cz>

The position of global quota file info does not change. So we do not have
to do logical -> physical block translation every time we reread it from
disk. Thus we can also avoid taking ip_alloc_sem.
Acked-by: NJoel Becker <Joel.Becker@oracle.com>
Signed-off-by: NJan Kara <jack@suse.cz>

There is no need to map offset of local dquot structure to on disk block
in each quota write. It is enough to map it just once and store the physical
block number in quota structure in memory. Moreover this simplifies locking
as we do not have to take ip_alloc_sem from quota write path.
Acked-by: NJoel Becker <Joel.Becker@oracle.com>
Signed-off-by: NJan Kara <jack@suse.cz>

Currently, __dquot_transfer() acquires its own references of dquot structures
that will be put into inode. But for OCFS2, this creates a lock inversion
between dq_lock (waited on in dqget) and transaction start (started in
ocfs2_setattr). Currently, deadlock is impossible because dq_lock is acquired
only during dquot_acquire and dquot_release and we already hold a reference to
dquot structures in ocfs2_setattr so neither of these functions can be called
while we call dquot_transfer. But this is rather subtle and it is hard to teach
lockdep about it. So provide __dquot_transfer function that can be passed dquot
references directly. OCFS2 can then pass acquired dquot references directly to
__dquot_transfer with proper locking.
Signed-off-by: NJan Kara <jack@suse.cz>

Quota must being initialized if size or uid/git changes requested.
But initialization performed in two different places:
in case of i_size file system is responsible for dquot init
, but in case of uid/gid init will be called internally in
dquot_transfer().
This ambiguity makes code harder to understand.
Let's move this logic to one common helper function.
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NJan Kara <jack@suse.cz>

The methods already do these checks, so remove them in the quotactl
implementation to allow non-VFS quota implementations to also support
these calls.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>

Pass the larger struct fs_disk_quota to the ->set_dqblk operation so
that the Q_SETQUOTA and Q_XSETQUOTA operations can be implemented
with a single filesystem operation and we can retire the ->set_xquota
operation.  The additional information (RT-subvolume accounting and
warn counts) are left zero for the VFS quota implementation.

Add new fieldmask values for setting the numer of blocks and inodes
values which is required for the VFS quota, but wasn't for XFS.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>

Pass the larger struct fs_disk_quota to the ->get_dqblk operation so
that the Q_GETQUOTA and Q_XGETQUOTA operations can be implemented
with a single filesystem operation and we can retire the ->get_xquota
operation.  The additional information (RT-subvolume accounting and
warn counts) are left zero for the VFS quota implementation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>