03 Jan, 2013
1 commit
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Pull Ceph fixes from Sage Weil:
"Two of Alex's patches deal with a race when reseting server
connections for open RBD images, one demotes some non-fatal BUGs to
WARNs, and my patch fixes a protocol feature bit failure path."* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
libceph: fix protocol feature mismatch failure path
libceph: WARN, don't BUG on unexpected connection states
libceph: always reset osds when kicking
libceph: move linger requests sooner in kick_requests()
28 Dec, 2012
4 commits
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We should not set con->state to CLOSED here; that happens in
ceph_fault() in the caller, where it first asserts that the state
is not yet CLOSED. Avoids a BUG when the features don't match.Since the fail_protocol() has become a trivial wrapper, replace
calls to it with direct calls to reset_connection().Signed-off-by: Sage Weil
Reviewed-by: Alex Elder -
A number of assertions in the ceph messenger are implemented with
BUG_ON(), killing the system if connection's state doesn't match
what's expected. At this point our state model is (evidently) not
well understood enough for these assertions to trigger a BUG().
Convert all BUG_ON(con->state...) calls to be WARN_ON(con->state...)
so we learn about these issues without killing the machine.We now recognize that a connection fault can occur due to a socket
closure at any time, regardless of the state of the connection. So
there is really nothing we can assert about the state of the
connection at that point so eliminate that assertion.Reported-by: Ugis
Tested-by: Ugis
Signed-off-by: Alex Elder
Reviewed-by: Sage Weil -
When ceph_osdc_handle_map() is called to process a new osd map,
kick_requests() is called to ensure all affected requests are
updated if necessary to reflect changes in the osd map. This
happens in two cases: whenever an incremental map update is
processed; and when a full map update (or the last one if there is
more than one) gets processed.In the former case, the kick_requests() call is followed immediately
by a call to reset_changed_osds() to ensure any connections to osds
affected by the map change are reset. But for full map updates
this isn't done.Both cases should be doing this osd reset.
Rather than duplicating the reset_changed_osds() call, move it into
the end of kick_requests().Signed-off-by: Alex Elder
Reviewed-by: Sage Weil -
The kick_requests() function is called by ceph_osdc_handle_map()
when an osd map change has been indicated. Its purpose is to
re-queue any request whose target osd is different from what it
was when it was originally sent.It is structured as two loops, one for incomplete but registered
requests, and a second for handling completed linger requests.
As a special case, in the first loop if a request marked to linger
has not yet completed, it is moved from the request list to the
linger list. This is as a quick and dirty way to have the second
loop handle sending the request along with all the other linger
requests.Because of the way it's done now, however, this quick and dirty
solution can result in these incomplete linger requests never
getting re-sent as desired. The problem lies in the fact that
the second loop only arranges for a linger request to be sent
if it appears its target osd has changed. This is the proper
handling for *completed* linger requests (it avoids issuing
the same linger request twice to the same osd).But although the linger requests added to the list in the first loop
may have been sent, they have not yet completed, so they need to be
re-sent regardless of whether their target osd has changed.The first required fix is we need to avoid calling __map_request()
on any incomplete linger request. Otherwise the subsequent
__map_request() call in the second loop will find the target osd
has not changed and will therefore not re-send the request.Second, we need to be sure that a sent but incomplete linger request
gets re-sent. If the target osd is the same with the new osd map as
it was when the request was originally sent, this won't happen.
This can be fixed through careful handling when we move these
requests from the request list to the linger list, by unregistering
the request *before* it is registered as a linger request. This
works because a side-effect of unregistering the request is to make
the request's r_osd pointer be NULL, and *that* will ensure the
second loop actually re-sends the linger request.Processing of such a request is done at that point, so continue with
the next one once it's been moved.Signed-off-by: Alex Elder
Reviewed-by: Sage Weil
21 Dec, 2012
6 commits
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Pull Ceph update from Sage Weil:
"There are a few different groups of commits here. The largest is
Alex's ongoing work to enable the coming RBD features (cloning,
striping). There is some cleanup in libceph that goes along with it.Cyril and David have fixed some problems with NFS reexport (leaking
dentries and page locks), and there is a batch of patches from Yan
fixing problems with the fs client when running against a clustered
MDS. There are a few bug fixes mixed in for good measure, many of
which will be going to the stable trees once they're upstream.My apologies for the late pull. There is still a gremlin in the rbd
map/unmap code and I was hoping to include the fix for that as well,
but we haven't been able to confirm the fix is correct yet; I'll send
that in a separate pull once it's nailed down."* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (68 commits)
rbd: get rid of rbd_{get,put}_dev()
libceph: register request before unregister linger
libceph: don't use rb_init_node() in ceph_osdc_alloc_request()
libceph: init event->node in ceph_osdc_create_event()
libceph: init osd->o_node in create_osd()
libceph: report connection fault with warning
libceph: socket can close in any connection state
rbd: don't use ENOTSUPP
rbd: remove linger unconditionally
rbd: get rid of RBD_MAX_SEG_NAME_LEN
libceph: avoid using freed osd in __kick_osd_requests()
ceph: don't reference req after put
rbd: do not allow remove of mounted-on image
libceph: Unlock unprocessed pages in start_read() error path
ceph: call handle_cap_grant() for cap import message
ceph: Fix __ceph_do_pending_vmtruncate
ceph: Don't add dirty inode to dirty list if caps is in migration
ceph: Fix infinite loop in __wake_requests
ceph: Don't update i_max_size when handling non-auth cap
bdi_register: add __printf verification, fix arg mismatch
... -
In kick_requests(), we need to register the request before we
unregister the linger request. Otherwise the unregister will
reset the request's osd pointer to NULL.Signed-off-by: Alex Elder
Reviewed-by: Sage Weil -
The red-black node in the ceph osd request structure is initialized
in ceph_osdc_alloc_request() using rbd_init_node(). We do need to
initialize this, because in __unregister_request() we call
RB_EMPTY_NODE(), which expects the node it's checking to have
been initialized. But rb_init_node() is apparently overkill, and
may in fact be on its way out. So use RB_CLEAR_NODE() instead.For a little more background, see this commit:
4c199a93 rbtree: empty nodes have no color"Signed-off-by: Alex Elder
Reviewed-by: Sage Weil -
The red-black node node in the ceph osd event structure is not
initialized in create_osdc_create_event(). Because this node can
be the subject of a RB_EMPTY_NODE() call later on, we should ensure
the node is initialized properly for that.Signed-off-by: Alex Elder
Reviewed-by: Sage Weil -
The red-black node node in the ceph osd structure is not initialized
in create_osd(). Because this node can be the subject of a
RB_EMPTY_NODE() call later on, we should ensure the node is
initialized properly for that. Add a call to RB_CLEAR_NODE()
initialize it.Signed-off-by: Alex Elder
Reviewed-by: Sage Weil -
When a connection's socket disconnects, or if there's a protocol
error of some kind on the connection, a fault is signaled and
the connection is reset (closed and reopened, basically). We
currently get an error message on the log whenever this occurs.A ceph connection will attempt to reestablish a socket connection
repeatedly if a fault occurs. This means that these error messages
will get repeatedly added to the log, which is undesirable.Change the error message to be a warning, so they don't get
logged by default.Signed-off-by: Alex Elder
Reviewed-by: Sage Weil
18 Dec, 2012
2 commits
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A connection's socket can close for any reason, independent of the
state of the connection (and without irrespective of the connection
mutex). As a result, the connectino can be in pretty much any state
at the time its socket is closed.Handle those other cases at the top of con_work(). Pull this whole
block of code into a separate function to reduce the clutter.Signed-off-by: Alex Elder
Reviewed-by: Sage Weil -
In __unregister_linger_request(), the request is being removed
from the osd client's req_linger list only when the request
has a non-null osd pointer. It should be done whether or not
the request currently has an osd.This is most likely a non-issue because I believe the request
will always have an osd when this function is called.Signed-off-by: Alex Elder
Reviewed-by: Sage Weil
17 Dec, 2012
2 commits
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If an osd has no requests and no linger requests, __reset_osd()
will just remove it with a call to __remove_osd(). That drops
a reference to the osd, and therefore the osd may have been free
by the time __reset_osd() returns. That function offers no
indication this may have occurred, and as a result the osd will
continue to be used even when it's no longer valid.Change__reset_osd() so it returns an error (ENODEV) when it
deletes the osd being reset. And change __kick_osd_requests() so it
returns immediately (before referencing osd again) if __reset_osd()
returns *any* error.Signed-off-by: Alex Elder
Reviewed-by: Sage Weil -
In __unregister_request(), there is a call to list_del_init()
referencing a request that was the subject of a call to
ceph_osdc_put_request() on the previous line. This is not
safe, because the request structure could have been freed
by the time we reach the list_del_init().Fix this by reversing the order of these lines.
Signed-off-by: Alex Elder
Reviewed-off-by: Sage Weil
13 Dec, 2012
1 commit
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This would reset a connection with any OSD that had an outstanding
request that was taking more than N seconds. The idea was that if the
OSD was buggy, the client could compensate by resending the request.In reality, this only served to hide server bugs, and we haven't
actually seen such a bug in quite a while. Moreover, the userspace
client code never did this.More importantly, often the request is taking a long time because the
OSD is trying to recover, or overloaded, and killing the connection
and retrying would only make the situation worse by giving the OSD
more work to do.Signed-off-by: Sage Weil
Reviewed-by: Alex Elder
01 Nov, 2012
1 commit
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Define and export function ceph_pg_pool_name_by_id() to supply
the name of a pg pool whose id is given. This will be used by
the next patch.Signed-off-by: Alex Elder
Reviewed-by: Josh Durgin
30 Oct, 2012
1 commit
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Ensure that we set the err value correctly so that we do not pass a 0
value to ERR_PTR and confuse the calling code. (In particular,
osd_client.c handle_map() will BUG(!newmap)).Signed-off-by: Sage Weil
Reviewed-by: Alex Elder
29 Oct, 2012
1 commit
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Pull Ceph fixes form Sage Weil:
"There are two fixes in the messenger code, one that can trigger a NULL
dereference, and one that error in refcounting (extra put). There is
also a trivial fix that in the fs client code that is triggered by NFS
reexport."* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
ceph: fix dentry reference leak in encode_fh()
libceph: avoid NULL kref_put when osd reset races with alloc_msg
rbd: reset BACKOFF if unable to re-queue
27 Oct, 2012
1 commit
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The ceph_on_in_msg_alloc() method calls the ->alloc_msg() helper which
may return NULL. It also drops con->mutex while it allocates a message,
which means that the connection state may change (e.g., get closed). If
that happens, we clean up and bail out. Avoid calling ceph_msg_put() on
a NULL return value and triggering a crash.This was observed when an ->alloc_msg() call races with a timeout that
resends a zillion messages and resets the connection, and ->alloc_msg()
returns NULL (because the request was resent to another target).Fixes http://tracker.newdream.net/issues/3342
Signed-off-by: Sage Weil
Reviewed-by: Alex Elder
25 Oct, 2012
1 commit
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The ceph_on_in_msg_alloc() method drops con->mutex while it allocates a
message. If that races with a timeout that resends a zillion messages and
resets the connection, and the ->alloc_msg() method returns a NULL message,
it will call ceph_msg_put(NULL) and BUG.Fix by only calling put if msg is non-NULL.
Fixes http://tracker.newdream.net/issues/3142
Signed-off-by: Sage Weil
15 Oct, 2012
1 commit
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Pull module signing support from Rusty Russell:
"module signing is the highlight, but it's an all-over David Howells frenzy..."Hmm "Magrathea: Glacier signing key". Somebody has been reading too much HHGTTG.
* 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (37 commits)
X.509: Fix indefinite length element skip error handling
X.509: Convert some printk calls to pr_devel
asymmetric keys: fix printk format warning
MODSIGN: Fix 32-bit overflow in X.509 certificate validity date checking
MODSIGN: Make mrproper should remove generated files.
MODSIGN: Use utf8 strings in signer's name in autogenerated X.509 certs
MODSIGN: Use the same digest for the autogen key sig as for the module sig
MODSIGN: Sign modules during the build process
MODSIGN: Provide a script for generating a key ID from an X.509 cert
MODSIGN: Implement module signature checking
MODSIGN: Provide module signing public keys to the kernel
MODSIGN: Automatically generate module signing keys if missing
MODSIGN: Provide Kconfig options
MODSIGN: Provide gitignore and make clean rules for extra files
MODSIGN: Add FIPS policy
module: signature checking hook
X.509: Add a crypto key parser for binary (DER) X.509 certificates
MPILIB: Provide a function to read raw data into an MPI
X.509: Add an ASN.1 decoder
X.509: Add simple ASN.1 grammar compiler
...
10 Oct, 2012
3 commits
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This patch defines a single function, queue_con_delay() to call
queue_delayed_work() for a connection. It basically generalizes
what was previously queue_con() by adding the delay argument.
queue_con() is now a simple helper that passes 0 for its delay.
queue_con_delay() returns 0 if it queued work or an errno if it
did not for some reason.If con_work() finds the BACKOFF flag set for a connection, it now
calls queue_con_delay() to handle arranging to start again after a
delay.Note about connection reference counts: con_work() only ever gets
called as a work item function. At the time that work is scheduled,
a reference to the connection is acquired, and the corresponding
con_work() call is then responsible for dropping that reference
before it returns.Previously, the backoff handling inside con_work() silently handed
off its reference to delayed work it scheduled. Now that
queue_con_delay() is used, a new reference is acquired for the
newly-scheduled work, and the original reference is dropped by the
con->ops->put() call at the end of the function.Signed-off-by: Alex Elder
Reviewed-by: Sage Weil -
Both ceph_fault() and con_work() include handling for imposing a
delay before doing further processing on a faulted connection.
The latter is used only if ceph_fault() is unable to.Instead, just let con_work() always be responsible for implementing
the delay. After setting up the delay value, set the BACKOFF flag
on the connection unconditionally and call queue_con() to ensure
con_work() will get called to handle it.Signed-off-by: Alex Elder
Reviewed-by: Sage Weil -
If ceph_fault() is unable to queue work after a delay, it sets the
BACKOFF connection flag so con_work() will attempt to do so.In con_work(), when BACKOFF is set, if queue_delayed_work() doesn't
result in newly-queued work, it simply ignores this condition and
proceeds as if no backoff delay were desired. There are two
problems with this--one of which is a bug.The first problem is simply that the intended behavior is to back
off, and if we aren't able queue the work item to run after a delay
we're not doing that.The only reason queue_delayed_work() won't queue work is if the
provided work item is already queued. In the messenger, this
means that con_work() is already scheduled to be run again. So
if we simply set the BACKOFF flag again when this occurs, we know
the next con_work() call will again attempt to hold off activity
on the connection until after the delay.The second problem--the bug--is a leak of a reference count. If
queue_delayed_work() returns 0 in con_work(), con->ops->put() drops
the connection reference held on entry to con_work(). However,
processing is (was) allowed to continue, and at the end of the
function a second con->ops->put() is called.This patch fixes both problems.
Signed-off-by: Alex Elder
Reviewed-by: Sage Weil
09 Oct, 2012
1 commit
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Empty nodes have no color. We can make use of this property to simplify
the code emitted by the RB_EMPTY_NODE and RB_CLEAR_NODE macros. Also,
we can get rid of the rb_init_node function which had been introduced by
commit 88d19cf37952 ("timers: Add rb_init_node() to allow for stack
allocated rb nodes") to avoid some issue with the empty node's color not
being initialized.I'm not sure what the RB_EMPTY_NODE checks in rb_prev() / rb_next() are
doing there, though. axboe introduced them in commit 10fd48f2376d
("rbtree: fixed reversed RB_EMPTY_NODE and rb_next/prev"). The way I
see it, the 'empty node' abstraction is only used by rbtree users to
flag nodes that they haven't inserted in any rbtree, so asking the
predecessor or successor of such nodes doesn't make any sense.One final rb_init_node() caller was recently added in sysctl code to
implement faster sysctl name lookups. This code doesn't make use of
RB_EMPTY_NODE at all, and from what I could see it only called
rb_init_node() under the mistaken assumption that such initialization was
required before node insertion.[sfr@canb.auug.org.au: fix net/ceph/osd_client.c build]
Signed-off-by: Michel Lespinasse
Cc: Andrea Arcangeli
Acked-by: David Woodhouse
Cc: Rik van Riel
Cc: Peter Zijlstra
Cc: Daniel Santos
Cc: Jens Axboe
Cc: "Eric W. Biederman"
Cc: John Stultz
Signed-off-by: Stephen Rothwell
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Oct, 2012
1 commit
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Give the key type the opportunity to preparse the payload prior to the
instantiation and update routines being called. This is done with the
provision of two new key type operations:int (*preparse)(struct key_preparsed_payload *prep);
void (*free_preparse)(struct key_preparsed_payload *prep);If the first operation is present, then it is called before key creation (in
the add/update case) or before the key semaphore is taken (in the update and
instantiate cases). The second operation is called to clean up if the first
was called.preparse() is given the opportunity to fill in the following structure:
struct key_preparsed_payload {
char *description;
void *type_data[2];
void *payload;
const void *data;
size_t datalen;
size_t quotalen;
};Before the preparser is called, the first three fields will have been cleared,
the payload pointer and size will be stored in data and datalen and the default
quota size from the key_type struct will be stored into quotalen.The preparser may parse the payload in any way it likes and may store data in
the type_data[] and payload fields for use by the instantiate() and update()
ops.The preparser may also propose a description for the key by attaching it as a
string to the description field. This can be used by passing a NULL or ""
description to the add_key() system call or the key_create_or_update()
function. This cannot work with request_key() as that required the description
to tell the upcall about the key to be created.This, for example permits keys that store PGP public keys to generate their own
name from the user ID and public key fingerprint in the key.The instantiate() and update() operations are then modified to look like this:
int (*instantiate)(struct key *key, struct key_preparsed_payload *prep);
int (*update)(struct key *key, struct key_preparsed_payload *prep);and the new payload data is passed in *prep, whether or not it was preparsed.
Signed-off-by: David Howells
Signed-off-by: Rusty Russell
02 Oct, 2012
5 commits
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If we are creating an osd request and get an invalid layout, return
an EINVAL to the caller. We switch up the return to have an error
code instead of NULL implying -ENOMEM.Signed-off-by: Sage Weil
Reviewed-by: Alex Elder -
If we encounter an invalid (e.g., zeroed) mapping, return an error
and avoid a divide by zero.Signed-off-by: Sage Weil
Reviewed-by: Alex Elder -
Using list_move_tail() instead of list_del() + list_add_tail().
Signed-off-by: Wei Yongjun
Signed-off-by: Sage Weil -
Make ceph_monc_do_poolop() static to remove the following sparse warning:
* net/ceph/mon_client.c:616:5: warning: symbol 'ceph_monc_do_poolop' was not
declared. Should it be static?
Also drops the 'ceph_monc_' prefix, now being a private function.Signed-off-by: Iulius Curt
Signed-off-by: Sage Weil -
This is unused; use monc->client->have_fsid.
Signed-off-by: Sage Weil
22 Sep, 2012
1 commit
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In write_partial_msg_pages(), pages need to be kmapped in order to
perform a CRC-32c calculation on them. As an artifact of the way
this code used to be structured, the kunmap() call was separated
from the kmap() call and both were done conditionally. But the
conditions under which the kmap() and kunmap() calls were made
differed, so there was a chance a kunmap() call would be done on a
page that had not been mapped.The symptom of this was tripping a BUG() in kunmap_high() when
pkmap_count[nr] became 0.Reported-by: Bryan K. Wright
Signed-off-by: Alex Elder
Reviewed-by: Sage Weil
22 Aug, 2012
1 commit
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Because the Ceph client messenger uses a non-blocking connect, it is
possible for the sending of the client banner to race with the
arrival of the banner sent by the peer.When ceph_sock_state_change() notices the connect has completed, it
schedules work to process the socket via con_work(). During this
time the peer is writing its banner, and arrival of the peer banner
races with con_work().If con_work() calls try_read() before the peer banner arrives, there
is nothing for it to do, after which con_work() calls try_write() to
send the client's banner. In this case Ceph's protocol negotiation
can complete succesfully.The server-side messenger immediately sends its banner and addresses
after accepting a connect request, *before* actually attempting to
read or verify the banner from the client. As a result, it is
possible for the banner from the server to arrive before con_work()
calls try_read(). If that happens, try_read() will read the banner
and prepare protocol negotiation info via prepare_write_connect().
prepare_write_connect() calls con_out_kvec_reset(), which discards
the as-yet-unsent client banner. Next, con_work() calls
try_write(), which sends the protocol negotiation info rather than
the banner that the peer is expecting.The result is that the peer sees an invalid banner, and the client
reports "negotiation failed".Fix this by moving con_out_kvec_reset() out of
prepare_write_connect() to its callers at all locations except the
one where the banner might still need to be sent.[elder@inktak.com: added note about server-side behavior]
Signed-off-by: Jim Schutt
Reviewed-by: Alex Elder
21 Aug, 2012
1 commit
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The debugfs directory includes the cluster fsid and our unique global_id.
We need to delay the initialization of the debug entry until we have
learned both the fsid and our global_id from the monitor or else the
second client can't create its debugfs entry and will fail (and multiple
client instances aren't properly reflected in debugfs).Reported by: Yan, Zheng
Signed-off-by: Sage Weil
Reviewed-by: Yehuda Sadeh
03 Aug, 2012
1 commit
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Avoid crashing if the crypto key payload was NULL, as when it was not correctly
allocated and initialized. Also, avoid leaking it.Signed-off-by: Sylvain Munaut
Signed-off-by: Sage Weil
Reviewed-by: Alex Elder
01 Aug, 2012
1 commit
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Pull Ceph changes from Sage Weil:
"Lots of stuff this time around:- lots of cleanup and refactoring in the libceph messenger code, and
many hard to hit races and bugs closed as a result.
- lots of cleanup and refactoring in the rbd code from Alex Elder,
mostly in preparation for the layering functionality that will be
coming in 3.7.
- some misc rbd cleanups from Josh Durgin that are finally going
upstream
- support for CRUSH tunables (used by newer clusters to improve the
data placement)
- some cleanup in our use of d_parent that Al brought up a while back
- a random collection of fixes across the treeThere is another patch coming that fixes up our ->atomic_open()
behavior, but I'm going to hammer on it a bit more before sending it."Fix up conflicts due to commits that were already committed earlier in
drivers/block/rbd.c, net/ceph/{messenger.c, osd_client.c}* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (132 commits)
rbd: create rbd_refresh_helper()
rbd: return obj version in __rbd_refresh_header()
rbd: fixes in rbd_header_from_disk()
rbd: always pass ops array to rbd_req_sync_op()
rbd: pass null version pointer in add_snap()
rbd: make rbd_create_rw_ops() return a pointer
rbd: have __rbd_add_snap_dev() return a pointer
libceph: recheck con state after allocating incoming message
libceph: change ceph_con_in_msg_alloc convention to be less weird
libceph: avoid dropping con mutex before fault
libceph: verify state after retaking con lock after dispatch
libceph: revoke mon_client messages on session restart
libceph: fix handling of immediate socket connect failure
ceph: update MAINTAINERS file
libceph: be less chatty about stray replies
libceph: clear all flags on con_close
libceph: clean up con flags
libceph: replace connection state bits with states
libceph: drop unnecessary CLOSED check in socket state change callback
libceph: close socket directly from ceph_con_close()
...
31 Jul, 2012
3 commits
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We drop the lock when calling the ->alloc_msg() con op, which means
we need to (a) not clobber con->in_msg without the mutex held, and (b)
we need to verify that we are still in the OPEN state when we retake
it to avoid causing any mayhem. If the state does change, -EAGAIN
will get us back to con_work() and loop.Signed-off-by: Sage Weil
Reviewed-by: Alex Elder -
This function's calling convention is very limiting. In particular,
we can't return any error other than ENOMEM (and only implicitly),
which is a problem (see next patch).Instead, return an normal 0 or error code, and make the skip a pointer
output parameter. Drop the useless in_hdr argument (we have the con
pointer).Signed-off-by: Sage Weil
Reviewed-by: Alex Elder -
The ceph_fault() function takes the con mutex, so we should avoid
dropping it before calling it. This fixes a potential race with
another thread calling ceph_con_close(), or _open(), or similar (we
don't reverify con->state after retaking the lock).Add annotation so that lockdep realizes we will drop the mutex before
returning.Signed-off-by: Sage Weil
Reviewed-by: Alex Elder