There are currently three libceph-level timeouts that the user can
specify on mount: mount_timeout, osd_idle_ttl and osdkeepalive.  All of
these are in seconds and no checking is done on user input: negative
values are accepted, we multiply them all by HZ which may or may not
overflow, arbitrarily large jiffies then get added together, etc.

There is also a bug in the way mount_timeout=0 is handled.  It's
supposed to mean "infinite timeout", but that's not how wait.h APIs
treat it and so __ceph_open_session() for example will busy loop
without much chance of being interrupted if none of ceph-mons are
there.

Fix all this by verifying user input, storing timeouts capped by
msecs_to_jiffies() in jiffies and using the new ceph_timeout_jiffies()
helper for all user-specified waits to handle infinite timeouts
correctly.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

setfilelock requests can block for a long time, which can prevent
client from advancing its oldest tid.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Previously we pre-allocate cap release messages for each caps. This
wastes lots of memory when there are large amount of caps. This patch
make the code not pre-allocate the cap release messages. Instead,
we add the corresponding ceph_cap struct to a list when releasing a
cap. Later when flush cap releases is needed, we allocate the cap
release messages dynamically.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

use an atomic variable to track number of sessions, this can avoid block
operation inside wait loops.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

mark session as readonly and wake up all cap waiters.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Add a new parameter 'locked_page' to ceph_do_getattr(). If inline data
in getattr reply will be copied to the page.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

When a lock operation is interrupted, current code sends a unlock request to
MDS to undo the lock operation. This method does not work as expected because
the unlock request can drop locks that have already been acquired.

The fix is use the newly introduced CEPH_LOCK_FCNTL_INTR/CEPH_LOCK_FLOCK_INTR
requests to interrupt blocked file lock request. These requests do not drop
locks that have alread been acquired, they only interrupt blocked file lock
request.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

...so that it can be used from the ceph debugfs
code when dumping session info.
Signed-off-by: NJohn Spray <john.spray@redhat.com>

Current code uses page array to present MDS request data. Pages in the
array are allocated/freed by caller of ceph_mdsc_do_request(). If request
is interrupted, the pages can be freed while they are still being used by
the request message.

The fix is use pagelist to present MDS request data. Pagelist is
reference counted.
Signed-off-by: NYan, Zheng <zyan@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

We recently modified the client/MDS protocol to include a timestamp in the
client request.  This allows ctime updates to follow the client's clock
in most cases, which avoids subtle problems when clocks are out of sync
and timestamps are updated sometimes by the MDS clock (for most requests)
and sometimes by the client clock (for cap writeback).
Signed-off-by: NSage Weil <sage@inktank.com>

Preallocate buffer for readdir reply. Limit number of entries in
readdir reply according to the buffer size.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>

Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>

When a cap get released while composing the cap reconnect message.
We should skip queuing the release message if the cap hasn't been
added to the cap reconnect message.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Hold the uid and gid for a pending ceph mds request using the types
kuid_t and kgid_t.  When a request message is finally created convert
the kuid_t and kgid_t values into uids and gids in the initial user
namespace.

Cc: Sage Weil <sage@inktank.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

The mds now sends back a created inode if the create request
performed the create.  If the file already existed, no inode is
returned in the reply.  This allows ceph to set the created flag
in atomic_open so that permissions are properly checked in the case
that the file wasn't created by the create call to the mds.

To ensure compability with previous kernels, a feature for sending
back the inode in the create reply was added, so that the mds will
only send back the inode if the client indicates it supports the
feature.
Signed-off-by: NSam Lang <sam.lang@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

The definitions for the ceph_mds_session and ceph_osd both contain
five fields related only to "authorizers."  Encapsulate those fields
into their own struct type, allowing for better isolation in some
upcoming patches.

Fix the #includes in "linux/ceph/osd_client.h" to lay out their more
complete canonical path.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Lockdep was reporting a possible circular lock dependency in
dentry_lease_is_valid().  That function needs to sample the
session's s_cap_gen and and s_cap_ttl fields coherently, but needs
to do so while holding a dentry lock.  The s_cap_lock field was
being used to protect the two fields, but that can't be taken while
holding a lock on a dentry within the session.

In most cases, the s_cap_gen and s_cap_ttl fields only get operated
on separately.  But in three cases they need to be updated together.
Implement a new lock to protect the spots updating both fields
atomically is required.
Signed-off-by: NAlex Elder <elder@dreamhost.com>
Reviewed-by: NSage Weil <sage@newdream.net>

We have been using i_lock to protect all kinds of data structures in the
ceph_inode_info struct, including lists of inodes that we need to iterate
over while avoiding races with inode destruction.  That requires grabbing
a reference to the inode with the list lock protected, but igrab() now
takes i_lock to check the inode flags.

Changing the list lock ordering would be a painful process.

However, using a ceph-specific i_ceph_lock in the ceph inode instead of
i_lock is a simple mechanical change and avoids the ordering constraints
imposed by igrab().
Reported-by: NAmon Ott <a.ott@m-privacy.de>
Signed-off-by: NSage Weil <sage@newdream.net>

We carry a pin on the parent directory for the rename source and dest
dentries.  For the source it's r_locked_dir; we need to explicitly
reference the old_dentry parent as well, since the dentry's d_parent may
change between when the request was created and pinned and when it is
freed.
Reviewed-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

The lease mask is no longer used (and it changed a while back).  Instead,
use a non-zero duration to indicate that there is a lease being issued.
Reviewed-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

In e9964c10 we change cap flushing to do a delicate dance because some
inodes on the cap_dirty list could be in a migrating state (got EXPORT but
not IMPORT) in which we couldn't actually flush and move from
dirty->flushing, breaking the while (!empty) { process first } loop
structure.  It worked for a single sync thread, but was not reentrant and
triggered infinite loops when multiple syncers came along.

Instead, move inodes with dirty to a separate cap_dirty_migrating list
when in the limbo export-but-no-import state, allowing us to go back to
the simple loop structure (which was reentrant).  This is cleaner and more
robust.

Audited the cap_dirty users and this looks fine:
list_empty(&ci->i_dirty_item) is still a reliable indicator of whether we
have dirty caps (which list we're on is irrelevant) and list_del_init()
calls still do the right thing.
Signed-off-by: NSage Weil <sage@newdream.net>

The r_mds field is redundant, since we can find the same information at
r_session->s_mds, and when r_session is NULL then r_mds is meaningless.
Signed-off-by: NSage Weil <sage@newdream.net>

This implements the DIRLAYOUTHASH protocol feature, which passes the dir
layout over the wire from the MDS.  This gives the client knowledge
of the correct hash function to use for mapping dentries among dir
fragments.

Note that if this feature is _not_ present on the client but is on the
MDS, the client may misdirect requests.  This will result in a forward
and degrade performance.  It may also result in inaccurate NFS filehandle
generation, which will prevent fh resolution when the inode is not present
in the client cache and the parent directories have been fragmented.
Signed-off-by: NSage Weil <sage@newdream.net>

Previously the kernel client incorrectly assumed everything was a directory.
Signed-off-by: NHerb Shiu <herb_shiu@tcloudcomputing.com>
Acked-by: NGreg Farnum <gregf@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

MDS requests can be rebuilt and resent in non-process context, but were
filling in uid/gid from current_fsuid/gid.  Put that information in the
request struct on request setup.

This fixes incorrect (and root) uid/gid getting set for requests that
are forwarded between MDSs, usually due to metadata migrations.
Signed-off-by: NSage Weil <sage@newdream.net>

This factors out protocol and low-level storage parts of ceph into a
separate libceph module living in net/ceph and include/linux/ceph.  This
is mostly a matter of moving files around.  However, a few key pieces
of the interface change as well:

 - ceph_client becomes ceph_fs_client and ceph_client, where the latter
   captures the mon and osd clients, and the fs_client gets the mds client
   and file system specific pieces.
 - Mount option parsing and debugfs setup is correspondingly broken into
   two pieces.
 - The mon client gets a generic handler callback for otherwise unknown
   messages (mds map, in this case).
 - The basic supported/required feature bits can be expanded (and are by
   ceph_fs_client).

No functional change, aside from some subtle error handling cases that got
cleaned up in the refactoring process.
Signed-off-by: NSage Weil <sage@newdream.net>

The use of a completion when waiting for session shutdown during umount is
inappropriate, given the complexity of the condition.  For multiple MDS's,
this resulted in the umount thread spinning, often preventing the session
close message from being processed in some cases.

Switch to a waitqueue and defined a condition helper.  This cleans things
up nicely.
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NGreg Farnum <gregf@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

When we get a cap EXPORT message, make sure we are connected to all export
targets to ensure we can handle the matching IMPORT.
Signed-off-by: NSage Weil <sage@newdream.net>

Caps related accounting is now being done per mds client instead
of just being global. This prepares ground work for a later revision
of the caps preallocated reservation list.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

Strip the cap and dentry releases from replayed messages.  They can
cause the shared state to get out of sync because they were generated
(with the request message) earlier, and no longer reflect the current
client state.
Signed-off-by: NSage Weil <sage@newdream.net>

If we have enough memory to allocate a new cap release message, do so, so
that we can send a partial release message immediately.  This keeps us from
making the MDS wait when the cap release it needs is in a partially full
release message.

If we fail because of ENOMEM, oh well, they'll just have to wait a bit
longer.
Signed-off-by: NSage Weil <sage@newdream.net>

If we get an IMPORT that give us a cap, but we don't have the inode, queue
a release (and try to send it immediately) so that the MDS doesn't get
stuck waiting for us.
Signed-off-by: NSage Weil <sage@newdream.net>

We invalidate I_COMPLETE and dentry leases in two places: on aborted mds
request and on request replay.  Use common helper to avoid duplicate code.
Signed-off-by: NSage Weil <sage@newdream.net>

When we abort requests we need to prevent fill_trace et al from doing
anything that relies on locks held by the VFS caller.  This fixes a race
between the reply handler and the abort code, ensuring that continue
holding the dir mutex until the reply handler completes.
Signed-off-by: NSage Weil <sage@newdream.net>

We would occasionally BUG out in the reply handler because r_reply was
nonzero, due to a race with ceph_mdsc_do_request temporarily setting
r_reply to an ERR_PTR value.  This is unnecessary, messy, and also wrong
in the EIO case.

Clean up by consistently using r_err for errors and r_reply for messages.
Also fix the abort logic to trigger consistently for all errors that return
to the caller early (e.g., EIO from timeout case).  If an abort races with
a reply, use the result from the reply.

Also fix locking for r_err, r_reply update in the reply handler.
Signed-off-by: NSage Weil <sage@newdream.net>