There are no races as locked mount flags are guaranteed to never change.
Moving the test into do_remount makes it more visible, and ensures all
filesystem remounts pass the MNT_LOCK_READONLY permission check. This
second case is not an issue today as filesystem remounts are guarded
by capable(CAP_DAC_ADMIN) and thus will always fail in less privileged
mount namespaces, but it could become an issue in the future.
Cc: stable@vger.kernel.org
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Kenton Varda <kenton@sandstorm.io> discovered that by remounting a
read-only bind mount read-only in a user namespace the
MNT_LOCK_READONLY bit would be cleared, allowing an unprivileged user
to the remount a read-only mount read-write.
Correct this by replacing the mask of mount flags to preserve
with a mask of mount flags that may be changed, and preserve
all others. This ensures that any future bugs with this mask and
remount will fail in an easy to detect way where new mount flags
simply won't change.
Cc: stable@vger.kernel.org
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
...to better match other functions that deal with open/lock stateids.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When we remove the client_mutex, we'll have a potential race between
FREE_STATEID and CLOSE.
The root of the problem is that we are walking the st_locks list,
dropping the spinlock and then trying to release the persistent
reference to the lockstateid. In between, a FREE_STATEID call can come
along and take the lock, find the stateid and then try to put the
reference. That leads to a double put.
Fix this by not releasing the cl_lock in order to release each lock
stateid. Use put_generic_stateid_locked to unhash them and gather them
onto a list, and free_ol_stateid_reaplist to free any that end up on the
list.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Releasing an openowner is a bit inefficient as it can potentially thrash
the cl_lock if you have a lot of stateids attached to it. Once we remove
the client_mutex, it'll also potentially be dangerous to do this.
Add some functions to make it easier to defer the part of putting a
generic stateid reference that needs to be done outside the cl_lock while
doing the parts that must be done while holding it under a single lock.
First we unhash each open stateid. Then we call
put_generic_stateid_locked which will put the reference to an
nfs4_ol_stateid. If it turns out to be the last reference, it'll go
ahead and remove the stid from the IDR tree and put it onto the reaplist
using the st_locks list_head.
Then, after dropping the lock we'll call free_ol_stateid_reaplist to
walk the list of stateids that are fully unhashed and ready to be freed,
and free each of them. This function can sleep, so it must be done
outside any spinlocks.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Once we remove the client_mutex, it'll be possible for the sc_type of a
lock stateid to change after it's found and checked, but before we can
go to destroy it. If that happens, we can end up putting the persistent
reference to the stateid more than once, and unhash it more than once.
Fix this by unhashing the lock stateid prior to dropping the cl_lock but
after finding it.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reduce the cl_lock trashing in destroy_lockowner. Unhash all of the
lockstateids on the lockowner's list. Put the reference under the lock
and see if it was the last one. If so, then add it to a private list
to be destroyed after we drop the lock.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Once we remove the client_mutex, we'll need to properly protect
the stateowner reference counts using the cl_lock.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Do more within the main loop, and simplify the function a bit. Also,
there's no need to take a stateowner reference unless we're going to call
release_lockowner.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Preparation for removing the client_mutex.
Convert the open owner hash table into a per-client table and protect it
using the nfs4_client->cl_lock spin lock.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Once we remove client mutex protection, we'll need to ensure that
stateowner lookup and creation are atomic between concurrent compounds.
Ensure that alloc_init_lock_stateowner checks the hashtable under the
client_lock before adding a new element.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Once we remove client mutex protection, we'll need to ensure that
stateowner lookup and creation are atomic between concurrent compounds.
Ensure that alloc_init_open_stateowner checks the hashtable under the
client_lock before adding a new element.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Once we remove client_mutex protection, it'll be possible to have an
in-flight operation using an openstateid when a CLOSE call comes in.
If that happens, we can't just put the sc_file reference and clear its
pointer without risking an oops.
Fix this by ensuring that v4.0 CLOSE operations wait for the refcount
to drop before proceeding to do so.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Change it so that only openstateids hold persistent references to
openowners. References can still be held by compounds in progress.
With this, we can get rid of NFS4_OO_NEW. It's possible that we
will create a new openowner in the process of doing the open, but
something later fails. In the meantime, another task could find
that openowner and start using it on a successful open. If that
occurs we don't necessarily want to tear it down, just put the
reference that the failing compound holds.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that lockowner references are only held by lockstateids and
operations that are in-progress. With this, we can get rid of
release_lockowner_if_empty, which will be racy once we remove
client_mutex protection.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
A necessary step toward client_mutex removal.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Allow stateowners to be unhashed and destroyed when the last reference
is put. The unhashing must be idempotent. In a future patch, we'll add
some locking around it, but for now it's only protected by the
client_mutex.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that when finding or creating a lockowner, that we get a
reference to it. For now, we also take an extra reference when a
lockowner is created that can be put when release_lockowner is called,
but we'll remove that in a later patch once we change how references are
held.
Since we no longer destroy lockowners in the event of an error in
nfsd4_lock, we must change how the seqid gets bumped in the lk_is_new
case. Instead of doing so on creation, do it manually in nfsd4_lock.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We don't want to rely on the client_mutex for protection in the case of
NFSv4 open owners. Instead, we add a mutex that will only be taken for
NFSv4.0 state mutating operations, and that will be released once the
entire compound is done.
Also, ensure that nfsd4_cstate_assign_replay/nfsd4_cstate_clear_replay
take a reference to the stateowner when they are using it for NFSv4.0
open and lock replay caching.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The way stateowners are managed today is somewhat awkward. They need to
be explicitly destroyed, even though the stateids reference them. This
will be particularly problematic when we remove the client_mutex.
We may create a new stateowner and attempt to open a file or set a lock,
and have that fail. In the meantime, another RPC may come in that uses
that same stateowner and succeed. We can't have the first task tearing
down the stateowner in that situation.
To fix this, we need to change how stateowners are tracked altogether.
Refcount them and only destroy them once all stateids that reference
them have been destroyed. This patch starts by adding the refcounting
necessary to do that.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Allow nfs4_find_stateid_by_type to take the stateid reference, while
still holding the &cl->cl_lock. Necessary step toward client_mutex
removal.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Allow nfs4_lookup_stateid to take the stateid reference, instead
of having all the callers do so.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Allow nfs4_preprocess_seqid_op to take the stateid reference, instead
of having all the callers do so.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that all the callers put the open stateid after use.
Necessary step toward client_mutex removal.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that nfsd4_open_confirm() keeps a reference to the open
stateid until it is done working with it.
Necessary step toward client_mutex removal.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Prepare nfsd4_close for a future where nfs4_preprocess_seqid_op()
hands it a fully referenced open stateid. Necessary step toward
client_mutex removal.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that nfsd4_process_open2() keeps a reference to the open
stateid until it is done working with it. Necessary step toward
client_mutex removal.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that nfsd4_process_open2() keeps a reference to the delegation
stateid until it is done working with it. Necessary step toward
client_mutex removal.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that nfs4_open_delegation() keeps a reference to the delegation
stateid until it is done working with it. Necessary step toward
client_mutex removal.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that nfsd4_locku() keeps a reference to the lock stateid
until it is done working with it. Necessary step toward client_mutex
removal.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that nfsd4_lock() references the lock stateid while it is
manipulating it. Not currently necessary, but will be once the
client_mutex is removed.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Hold the cl_lock over the bulk of these functions. In addition to
ensuring that they aren't freed prematurely, this will also help prevent
a potential race that could be introduced later. Once we remove the
client_mutex, it'll be possible for FREE_STATEID and CLOSE to race and
for both to try to put the "persistent" reference to the stateid.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Preparation for removal of the client_mutex.
Currently, no lock aside from the client_mutex is held when calling
find_lock_state. Ensure that the cl_lock is held by adding a lockdep
assertion.
Once we remove the client_mutex, it'll be possible for another thread to
race in and insert a lock state for the same file after we search but
before we insert a new one. Ensure that doesn't happen by redoing the
search after allocating a new stid that we plan to insert. If one is
found just put the one that was allocated.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Change to using the clp->cl_lock for this. For now, there's a lot of
cl_lock thrashing, but in later patches we'll eliminate that and close
the potential races that can occur when releasing the cl_lock while
walking the lists. For now, the client_mutex prevents those races.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Releasing locks when we unhash the stateid instead of doing so only when
the stateid is actually released will be problematic in later patches
when we need to protect the unhashing with spinlocks. Move it into the
sc_free operation instead.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Currently, this is serialized by the client_mutex, which is slated for
removal. Add finer-grained locking here. Also, do some cleanup around
find_stateid to prepare for taking references.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Benny Halevy <bhalevy@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
All stateids are associated with a nfs4_file. Let's consolidate.
Replace delegation->dl_file with the dl_stid.sc_file, and
nfs4_ol_stateid->st_file with st_stid.sc_file.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When we remove the client_mutex, we'll need to be able to ensure that
these objects aren't destroyed while we're not holding locks.
Add a ->free() callback to the struct nfs4_stid, so that we can
release a reference to the stid without caring about the contents.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We use a circle area to record the log nodes in ubifs. This log area
should not be overlapped. But after researching the code, I found
some conditions may lead log head wraps log ltail. Although we've
fixed the problems discovered, there may be some other issues still
left.
This patch adds assertions where lhead changes to next leb to make
sure ltail is not wrapped.
Signed-off-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
We do not need to block on ->node_write among different node page writers e.g.
fsync/flush, unless we have a node page writer from write_checkpoint.
So it's better use rw_semaphore instead of mutex type for ->node_write to
promote performance.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If there is a failure while allocating the preallocation structure, a
number of blocks can end up getting marked in the in-memory buddy
bitmap, and then not getting released. This can result in the
following corruption getting reported by the kernel:
EXT4-fs error (device sda3): ext4_mb_generate_buddy:758: group 1126,
12793 clusters in bitmap, 12729 in gd
In that case, we need to release the blocks using mb_free_blocks().
Tested: fs smoke test; also demonstrated that with injected errors,
the file system is no longer getting corrupted
Google-Bug-Id: 16657874
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
There are redundant lines in allocate_data_block.
In this function, we call refresh_sit_entry with old seg and old curseg.
After that, we call locate_dirty_segment with old curseg.
But, the new address is always allocated from old curseg and
we call locate_dirty_segment with old curseg in refresh_sit_entry.
So, we do not need to call locate_dirty_segment with old curseg again.
We've discussed like below:
Jaegeuk said:
"When considering SSR, we need to take care of the following scenario.
- old segno : X
- new address : Z
- old curseg : Y
This means, a new block is supposed to be written to Z from X.
And Z is newly allocated in the same path from Y.
In that case, we should trigger locate_dirty_segment for Y, since
it was a current_segment and can be dirty owing to SSR.
But that was not included in the dirty list."
Changman said:
"We already choosed old curseg(Y) and then we allocate new address(Z) from old
curseg(Y). After that we call refresh_sit_entry(old address, new address).
In the funcation, we call locate_dirty_segment with old seg and old curseg.
So calling locate_dirty_segment after refresh_sit_entry again is redundant."
Jaegeuk said:
"Right. The new address is always allocated from old_curseg."
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Dongho Sim <dh.sim@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If the bit is already set, we don't need to reset it, and vice versa.
Because we don't need to make the caches dirty for that.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch enforces in-place-updates only when fdatasync is requested.
If we adopt this in-place-updates for the fdatasync, we can skip to write the
recovery information.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch intends to improve the fsync performance by skipping remaining the
recovery information, only when there is no data that we should recover.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
