When an incoming message is destined for the osd client, the
messenger calls the osd client's alloc_msg method. That function
looks up which request has the tid matching the incoming message,
and returns the request message that was preallocated to receive the
response. The response message is therefore known before the
request is even started.
Between the start of the request and the receipt of the response,
the request and its data fields will not change, so there's no
reason we need to hold off setting them. In fact it's preferable
to set them just once because it's more obvious that they're
unchanging.
So set up the fields describing where incoming data is to land in a
response message at the beginning of ceph_osdc_start_request().
Define a helper function that sets these fields, and use it to
set the fields for both outgoing data in the request message and
incoming data in the response.
This resolves:
http://tracker.ceph.com/issues/4284
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Record the number of bytes of data in a page array rather than the
number of pages in the array. It can be assumed that the page array
is of sufficient size to hold the number of bytes indicated (and
offset by the indicated alignment).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Change it so we only assign outgoing data information for messages
if there is outgoing data to send.
This then allows us to add a few more (currently commented-out)
assertions.
This is related to:
http://tracker.ceph.com/issues/4284
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
Define ceph_msg_data_set_pagelist(), ceph_msg_data_set_bio(), and
ceph_msg_data_set_trail() to clearly abstract the assignment of the
remaining data-related fields in a ceph message structure. Use the
new functions in the osd client and mds client.
This partially resolves:
http://tracker.ceph.com/issues/4263
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When setting page array information for message data, provide the
byte length rather than the page count ceph_msg_data_set_pages().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Define a function ceph_msg_data_set_pages(), which more clearly
abstracts the assignment page-related fields for data in a ceph
message structure. Use this new function in the osd client and mds
client.
Ideally, these fields would never be set more than once (with
BUG_ON() calls to guarantee that). At the moment though the osd
client sets these every time it receives a message, and in the event
of a communication problem this can happen more than once. (This
will be resolved shortly, but setting up these helpers first makes
it all a bit easier to work with.)
Rearrange the field order in a ceph_msg structure to group those
that are used to define the possible data payloads.
This partially resolves:
http://tracker.ceph.com/issues/4263
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Record the byte count for an osd request rather than the page count.
The number of pages can always be derived from the byte count (and
alignment/offset) but the reverse is not true.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Rather than explicitly initializing many fields to 0, NULL, or false
in a newly-allocated message, just use kzalloc() for allocating new
messages. This will become a much more convenient way of doing
things anyway for upcoming patches that abstract the data field.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
While processing an outgoing pagelist (either the data pagelist or
trail) in a ceph message, the messenger cycles through each of the
pages on the list. This is accomplished in out_msg_pos_next(), if
the end of the first page on the list is reached, the first page is
moved to the end of the list.
There is a list operation, list_rotate_left(), which performs
exactly this operation, and by using it, what's really going on
becomes more obvious.
So replace these two list_move_tail() calls with list_rotate_left().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Define a new function in_msg_pos_next() to match out_msg_pos_next(),
and use it in place of code at the end of read_partial_message_pages()
and read_partial_message_bio().
Note that the page number is incremented and offset reset under
slightly different conditions from before. The result is
equivalent, however, as explained below.
Each time an incoming message is going to arrive, we find out how
much room is left--not surpassing the current page--and provide that
as the number of bytes to receive. So the amount we'll use is the
lesser of: all that's left of the entire request; and all that's
left in the current page.
If we received exactly how many were requested, we either reached
the end of the request or the end of the page. In the first case,
we're done, in the second, we move onto the next page in the array.
In all cases but (possibly) on the last page, after adding the
number of bytes received, page_pos == PAGE_SIZE. On the last page,
it doesn't really matter whether we increment the page number and
reset the page position, because we're done and we won't come back
here again. The code previously skipped over that last case,
basically. The new code handles that case the same as the others,
incrementing and resetting.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is only one caller for read_partial_message_bio(), and it
always passes &msg->bio_iter and &bio_seg as the second and third
arguments. Furthermore, the message in question is always the
connection's in_msg, and we can get that inside the called function.
So drop those two parameters and use their derived equivalents.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Change the type of the "more" parameter from int to bool.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Some values printed are not (necessarily) in CPU order. We already
have a copy of the converted versions, so use them.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This is probably unnecessary but the code read as if it were wrong
in read_partial_message().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In ceph_con_in_msg_alloc() it is possible for a connection's
alloc_msg method to indicate an incoming message should be skipped.
By default, read_partial_message() initializes the skip variable
to 0 before it gets provided to ceph_con_in_msg_alloc().
The osd client, mon client, and mds client each supply an alloc_msg
method. The mds client always assigns skip to be 0.
The other two leave the skip value of as-is, or assigns it to zero,
except:
- if no (osd or mon) request having the given tid is found, in
which case skip is set to 1 and NULL is returned; or
- in the osd client, if the data of the reply message is not
adequate to hold the message to be read, it assigns skip
value 1 and returns NULL.
So the returned message pointer will always be NULL if skip is ever
non-zero.
Clean up the logic a bit in ceph_con_in_msg_alloc() to make this
state of affairs more obvious. Add a comment explaining how a null
message pointer can mean either a message that should be skipped or
a problem allocating a message.
This resolves:
http://tracker.ceph.com/issues/4324
Reported-by: Greg Farnum <greg@inktank.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
An osd request defines information about where data to be read
should be placed as well as where data to write comes from.
Currently these are represented by common fields.
Keep information about data for writing separate from data to be
read by splitting these into data_in and data_out fields.
This is the key patch in this whole series, in that it actually
identifies which osd requests generate outgoing data and which
generate incoming data. It's less obvious (currently) that an osd
CALL op generates both outgoing and incoming data; that's the focus
of some upcoming work.
This resolves:
http://tracker.ceph.com/issues/4127
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An osd request uses either pages or a bio list for its data. Use a
union to record information about the two, and add a data type
tag to select between them.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Pull the fields in an osd request structure that define the data for
the request out into a separate structure.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Currently ceph_osdc_new_request() assigns an osd request's
r_num_pages and r_alignment fields. The only thing it does
after that is call ceph_osdc_build_request(), and that doesn't
need those fields to be assigned.
Move the assignment of those fields out of ceph_osdc_new_request()
and into its caller. As a result, the page_align parameter is no
longer used, so get rid of it.
Note that in ceph_sync_write(), the value for req->r_num_pages had
already been calculated earlier (as num_pages, and fortunately
it was computed the same way). So don't bother recomputing it,
but because it's not needed earlier, move that calculation after the
call to ceph_osdc_new_request(). Hold off making the assignment to
r_alignment, doing it instead r_pages and r_num_pages are
getting set.
Similarly, in start_read(), nr_pages already holds the number of
pages in the array (and is calculated the same way), so there's no
need to recompute it. Move the assignment of the page alignment
down with the others there as well.
This and the next few patches are preparation work for:
http://tracker.ceph.com/issues/4127
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The only user of the ceph messenger that doesn't define an alloc_msg
method is the mds client. Define one, such that it works just like
it did before, and simplify ceph_con_in_msg_alloc() by assuming the
alloc_msg method is always present.
This and the next patch resolve:
http://tracker.ceph.com/issues/4322
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
In ceph_con_in_msg_alloc(), if no alloc_msg method is defined for a
connection a new message is allocated with ceph_msg_new().
Drop the mutex before making this call, and make sure we're still
connected when we get it back again.
This is preparing for the next patch, which ensures all connections
define an alloc_msg method, and then handles them all the same way.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
The purpose of ceph_calc_object_layout() is to fill in the pool
number and seed for a ceph_pg structure provided, based on a given
osd map and target object id.
Currently that function takes a file layout parameter, but the only
thing used out of that is its pool number.
Change the function so it takes a pool number rather than the full
file layout structure. Only update the ceph_pg if the pool is found
in the osd map. Get rid of few useless lines of code from the
function while there.
Since the function now very clearly just fills in the ceph_pg
structure it's provided, rename it ceph_calc_ceph_pg().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The pagelist_count field is never actually used, so get rid of it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The new cases added to osd_req_encode_op() caused a new sparse
error, which highlighted an existing problem that had been
overlooked since it was originally checked in. When an unsupported
opcode is found the destination rather than the source opcode was
being used in the error message. The two differ in their byte
order, and we want to be using the one in the source.
Fix the problem in both spots.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An osd request marked to linger will be re-submitted in the event
a connection to the target osd gets dropped. Currently, if there
is a callback function associated with a request it will be called
each time a request is submitted--which for lingering requests can
be more than once.
Change it so a request--including lingering ones--will get completed
(from the perspective of the user of the osd client) exactly once.
This resolves:
http://tracker.ceph.com/issues/3967
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The page alignment field for a request is currently set in
ceph_osdc_build_request(). It's not needed at that point
nor do either of its callers need that value assigned at
any point before they call ceph_osdc_start_request().
So move that assignment into ceph_osdc_start_request().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Use distinct fields for tracking the number of pages in a message's
page array and in a message's page list. Currently only one or the
other is used at a time, but that will be changing soon.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The only remaining reason to pass the osd request to calc_layout()
is to fill in its r_num_pages and r_page_alignment fields. Once it
fills those in, it doesn't do anything more with them.
We can therefore move those assignments into the caller, and get rid
of the "req" parameter entirely.
Note, however, that the only caller is ceph_osdc_new_request(),
and that immediately overwrites those fields with values based on
its passed-in page offset. So the assignment inside calc_layout()
was redundant anyway.
This resolves:
http://tracker.ceph.com/issues/4262
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Move the formatting of the object name (oid) to use for an object
request into the caller of calc_layout(). This makes the "vino"
parameter no longer necessary, so get rid of it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Have calc_layout() pass the computed object number back to its
caller. (This is a small step to simplify review.)
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The bio_seg field is used by the ceph messenger in iterating through
a bio. It should never have a negative value, so make it an
unsigned. (I contemplated making it unsigned short to match the
struct bio definition, but it offered no benefit.)
Change variables used to hold bio_seg values to all be unsigned as
well. Change two variable names in init_bio_iter() to match the
convention used everywhere else.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
If an invalid layout is provided to ceph_osdc_new_request(), its
call to calc_layout() might return an error. At that point in the
function we've already allocated an osd request structure, so we
need to free it (drop a reference) in the event such an error
occurs.
The only other value calc_layout() will return is 0, so make that
explicit in the successful case.
This resolves:
http://tracker.ceph.com/issues/4240
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Pull Ceph fix from Sage Weil:
"This fixes a bug in the new message decoding that just went in during
the last window."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
libceph: fix decoding of pgids
In 4f6a7e5ee1 we effectively dropped support
for the legacy encoding for the OSDMap and incremental. However, we didn't
fix the decoding for the pgid.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Pull Ceph updates from Sage Weil:
"A few groups of patches here. Alex has been hard at work improving
the RBD code, layout groundwork for understanding the new formats and
doing layering. Most of the infrastructure is now in place for the
final bits that will come with the next window.
There are a few changes to the data layout. Jim Schutt's patch fixes
some non-ideal CRUSH behavior, and a set of patches from me updates
the client to speak a newer version of the protocol and implement an
improved hashing strategy across storage nodes (when the server side
supports it too).
A pair of patches from Sam Lang fix the atomicity of open+create
operations. Several patches from Yan, Zheng fix various mds/client
issues that turned up during multi-mds torture tests.
A final set of patches expose file layouts via virtual xattrs, and
allow the policies to be set on directories via xattrs as well
(avoiding the awkward ioctl interface and providing a consistent
interface for both kernel mount and ceph-fuse users)."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (143 commits)
libceph: add support for HASHPSPOOL pool flag
libceph: update osd request/reply encoding
libceph: calculate placement based on the internal data types
ceph: update support for PGID64, PGPOOL3, OSDENC protocol features
ceph: update "ceph_features.h"
libceph: decode into cpu-native ceph_pg type
libceph: rename ceph_pg -> ceph_pg_v1
rbd: pass length, not op for osd completions
rbd: move rbd_osd_trivial_callback()
libceph: use a do..while loop in con_work()
libceph: use a flag to indicate a fault has occurred
libceph: separate non-locked fault handling
libceph: encapsulate connection backoff
libceph: eliminate sparse warnings
ceph: eliminate sparse warnings in fs code
rbd: eliminate sparse warnings
libceph: define connection flag helpers
rbd: normalize dout() calls
rbd: barriers are hard
rbd: ignore zero-length requests
...
The legacy behavior adds the pgid seed and pool together as the input for
CRUSH. That is problematic because each pool's PGs end up mapping to the
same OSDs: 1.5 == 2.4 == 3.3 == ...
Instead, if the HASHPSPOOL flag is set, we has the ps and pool together and
feed that into CRUSH. This ensures that two adjacent pools will map to
an independent pseudorandom set of OSDs.
Advertise our support for this via a protocol feature flag.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Use the new version of the encoding for osd requests and replies. In the
process, update the way we are tracking request ops and reply lengths and
results in the struct ceph_osd_request. Update the rbd and fs/ceph users
appropriately.
The main changes are:
- we keep pointers into the request memory for fields we need to update
each time the request is sent out over the wire
- we keep information about the result in an array in the request struct
where the users can easily get at it.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Instead of using the old ceph_object_layout struct, update our internal
ceph_calc_object_layout method to use the ceph_pg type. This allows us to
pass the full 32-bit precision of the pgid.seed to the callers. It also
allows some callers to avoid reaching into the request structures for the
struct ceph_object_layout fields.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Support (and require) the PGID64, PGPOOL3, and OSDENC protocol features.
These have been present in ceph.git since v0.42, Feb 2012. Require these
features to simplify support; nobody is running older userspace.
Note that the new request and reply encoding is still not in place, so the new
code is not yet functional.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Always decode data into our cpu-native ceph_pg type that has the correct
field widths. Limit any remaining uses of ceph_pg_v1 to dealing with the
legacy protocol.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Rename the old version this type to distinguish it from the new version.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Pull user namespace and namespace infrastructure changes from Eric W Biederman:
"This set of changes starts with a few small enhnacements to the user
namespace. reboot support, allowing more arbitrary mappings, and
support for mounting devpts, ramfs, tmpfs, and mqueuefs as just the
user namespace root.
I do my best to document that if you care about limiting your
unprivileged users that when you have the user namespace support
enabled you will need to enable memory control groups.
There is a minor bug fix to prevent overflowing the stack if someone
creates way too many user namespaces.
The bulk of the changes are a continuation of the kuid/kgid push down
work through the filesystems. These changes make using uids and gids
typesafe which ensures that these filesystems are safe to use when
multiple user namespaces are in use. The filesystems converted for
3.9 are ceph, 9p, afs, ocfs2, gfs2, ncpfs, nfs, nfsd, and cifs. The
changes for these filesystems were a little more involved so I split
the changes into smaller hopefully obviously correct changes.
XFS is the only filesystem that remains. I was hoping I could get
that in this release so that user namespace support would be enabled
with an allyesconfig or an allmodconfig but it looks like the xfs
changes need another couple of days before it they are ready."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (93 commits)
cifs: Enable building with user namespaces enabled.
cifs: Convert struct cifs_ses to use a kuid_t and a kgid_t
cifs: Convert struct cifs_sb_info to use kuids and kgids
cifs: Modify struct smb_vol to use kuids and kgids
cifs: Convert struct cifsFileInfo to use a kuid
cifs: Convert struct cifs_fattr to use kuid and kgids
cifs: Convert struct tcon_link to use a kuid.
cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t
cifs: Convert from a kuid before printing current_fsuid
cifs: Use kuids and kgids SID to uid/gid mapping
cifs: Pass GLOBAL_ROOT_UID and GLOBAL_ROOT_GID to keyring_alloc
cifs: Use BUILD_BUG_ON to validate uids and gids are the same size
cifs: Override unmappable incoming uids and gids
nfsd: Enable building with user namespaces enabled.
nfsd: Properly compare and initialize kuids and kgids
nfsd: Store ex_anon_uid and ex_anon_gid as kuids and kgids
nfsd: Modify nfsd4_cb_sec to use kuids and kgids
nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion
nfsd: Convert nfsxdr to use kuids and kgids
nfsd: Convert nfs3xdr to use kuids and kgids
...
This just converts a manually-implemented loop into a do..while loop
in con_work(). It also moves handling of EAGAIN inside the blocks
where it's already been determined an error code was returned.
Also update a few dout() calls near the affected code for
consistency.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This just rearranges the logic in con_work() a little bit so that a
flag is used to indicate a fault has occurred. This allows both the
fault and non-fault case to be handled the same way and avoids a
couple of nearly consecutive gotos.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An error occurring on a ceph connection is treated as a fault,
causing the connection to be reset. The initial part of this fault
handling has to be done while holding the connection mutex, but
it must then be dropped for the last part.
Separate the part of this fault handling that executes without the
lock into its own function, con_fault_finish(). Move the call to
this new function, as well as call that drops the connection mutex,
into ceph_fault(). Rename that function con_fault() to reflect that
it's only handling the connection part of the fault handling.
The motivation for this was a warning from sparse about the locking
being done here. Rearranging things this way keeps all the mutex
manipulation within ceph_fault(), and this stops sparse from
complaining.
This partially resolves:
http://tracker.ceph.com/issues/4184
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Collect the code that tests for and implements a backoff delay for a
ceph connection into a new function, ceph_backoff().
Make the debug output messages in that part of the code report
things consistently by reporting a message in the socket closed
case, and by making the one for PREOPEN state report the connection
pointer like the rest.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Eliminate most of the problems in the libceph code that cause sparse
to issue warnings.
- Convert functions that are never referenced externally to have
static scope.
- Pass NULL rather than 0 for a pointer argument in one spot in
ceph_monc_delete_snapid()
This partially resolves:
http://tracker.ceph.com/issues/4184
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Define and use functions that encapsulate operations performed on
a connection's flags.
This resolves:
http://tracker.ceph.com/issues/4234
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The return values provided for ceph_copy_to_page_vector() and
ceph_copy_from_page_vector() serve no purpose, so get rid of them.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The functions used for working with ceph page vectors are defined
with char pointers, but they're really intended to operate on
untyped data. Change the types of these function parameters
to (void *) to reflect this.
(Note that the functions now assume void pointer arithmetic works
like arithmetic on char pointers.)
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Add support for CEPH_OSD_OP_STAT operations in the osd client
and in rbd.
This operation sends no data to the osd; everything required is
encoded in identity of the target object.
The result will be ENOENT if the object doesn't exist. If it does
exist and no other error occurs the server returns the size and last
modification time of the target object as output data (in little
endian format). The size is a 64 bit unsigned and the time is
ceph_timespec structure (two unsigned 32-bit integers, representing
a seconds and nanoseconds value).
This resolves:
http://tracker.ceph.com/issues/4007
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Simplify the way the data length recorded in a message header is
calculated in ceph_osdc_build_request().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In osd_req_encode_op() there are a few cases that handle osd
opcodes that are never used in the kernel. The presence of
this code gives the impression it's correct (which really can't
be assumed), and may impose some unnecessary restrictions on
some upcoming refactoring of this code.
So delete this effectively dead code, and report uses of the
previously handled cases as unsupported.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
If osd_req_encode_op() is given any opcode it doesn't recognize
it reports an error.
This patch fleshes out that routine to distinguish between
well-defined but unsupported values and values that are simply
bogus.
This and the next commit are related to:
http://tracker.ceph.com/issues/4126
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Update ceph_osd_op_name() to include the newly-added definitions in
"rados.h", and to match its counterpart in the user space code.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Add the definition of ceph_osd_state_name(), to match its
counterpart in user space.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There are no actual users of ceph_osdc_wait_event(). This would
have been one-shot events, but we no longer support those so just
get rid of this function.
Since this leaves nothing else that waits for the completion of an
event, we can get rid of the completion in a struct ceph_osd_event.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is only one caller of ceph_osdc_create_event(), and it
provides 0 as its "one_shot" argument. Get rid of that argument and
just use 0 in its place.
Replace the code in handle_watch_notify() that executes if one_shot
is nonzero in the event with a BUG_ON() call.
While modifying "osd_client.c", give handle_watch_notify() static
scope.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no caller of ceph_calc_raw_layout() outside of libceph, so
there's no need to export from the module.
Furthermore, there is only one caller, in calc_layout(), and it
is not much more than a simple wrapper for that function.
So get rid of ceph_calc_raw_layout() and embed it instead within
calc_layout().
While touching "osd_client.c", get rid of the unnecessary forward
declaration of __send_request().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The only callers of ceph_osdc_init() and ceph_osdc_stop()
ceph_create_client() and ceph_destroy_client() (respectively)
and they are in the same kernel module as those two functions.
There's therefore no need to export those interfaces, so don't.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Two of the three callers of the osd client's send_queued() function
already hold the osd client mutex and drop it before the call.
Change send_queued() so it assumes the caller holds the mutex, and
update all callers accordingly. Rename it __send_queued() to match
the convention used elsewhere in the file with respect to the lock.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The "num_reply" parameter to ceph_osdc_new_request() is never
used inside that function, so get rid of it.
Note that ceph_sync_write() passes 2 for that argument, while all
other callers pass 1. It doesn't matter, but perhaps someone should
verify this doesn't indicate a problem.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is only one caller of ceph_osdc_writepages(), and it always
passes 0 as its "flags" argument. Get rid of that argument and
replace its use in ceph_osdc_writepages() with 0.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is only one caller of ceph_osdc_writepages(), and it always
passes 0 as its "dosync" argument. Get rid of that argument and
replace its use in ceph_osdc_writepages() with 0.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is only one caller of ceph_osdc_writepages(), and it always
passes the value true as its "nofail" argument. Get rid of that
argument and replace its use in ceph_osdc_writepages() with the
constant value true.
This and a number of cleanup patches that follow resolve:
http://tracker.ceph.com/issues/4126
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is a check in the completion path for osd requests that
ensures the number of pages allocated is enough to hold the amount
of incoming data expected.
For bio requests coming from rbd the "number of pages" is not really
meaningful (although total length would be). So stop requiring that
nr_pages be supplied for bio requests. This is done by checking
whether the pages pointer is null before checking the value of
nr_pages.
Note that this value is passed on to the messenger, but there it's
only used for debugging--it's never used for validation.
While here, change another spot that used r_pages in a debug message
inappropriately, and also invalidate the r_con_filling_msg pointer
after dropping a reference to it.
This resolves:
http://tracker.ceph.com/issues/3875
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Currently, if the OSD client finds an osd request has had a bio list
attached to it, it drops a reference to it (or rather, to the first
entry on that list) when the request is released.
The code that added that reference (i.e., the rbd client) is
therefore required to take an extra reference to that first bio
structure.
The osd client doesn't really do anything with the bio pointer other
than transfer it from the osd request structure to outgoing (for
writes) and ingoing (for reads) messages. So it really isn't the
right place to be taking or dropping references.
Furthermore, the rbd client already holds references to all bio
structures it passes to the osd client, and holds them until the
request is completed. So there's no need for this extra reference
whatsoever.
So remove the bio_put() call in ceph_osdc_release_request(), as
well as its matching bio_get() call in rbd_osd_req_create().
This change could lead to a crash if old libceph.ko was used with
new rbd.ko. Add a compatibility check at rbd initialization time to
avoid this possibilty.
This resolves:
http://tracker.ceph.com/issues/3798 and
http://tracker.ceph.com/issues/3799
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An upcoming change implements semantic change that could lead to
a crash if an old version of the libceph kernel module is used with
a new version of the rbd kernel module.
In order to preclude that possibility, this adds a compatibilty
check interface. If this interface doesn't exist, the modules are
obviously not compatible. But if it does exist, this provides a way
of letting the caller know whether it will operate properly with
this libceph module.
Perhaps confusingly, it returns false right now. The semantic
change mentioned above will make it return true.
This resolves:
http://tracker.ceph.com/issues/3800
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The ceph messenger has a few spots that are only used when
bio messages are supported, and that's only when CONFIG_BLOCK
is defined. This surrounds a couple of spots with #ifdef's
that would cause a problem if CONFIG_BLOCK were not present
in the kernel configuration.
This resolves:
http://tracker.ceph.com/issues/3976
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Today ceph opens tcp sockets from a delayed work callback. Delayed
work happens from kernel threads which are always in the initial
network namespace. Therefore fail early if someone attempts
to mount a ceph filesystem from something other than the initial
network namespace.
Cc: Sage Weil <sage@inktank.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The variable "str" is used as both the source and destination in
function snprintf(), which is undefined behavior based on C11. The
original description in C11 is:
"If copying takes place between objects that
overlap, the behavior is undefined."
And, the function of ceph_osdmap_state_str() is to return the osdmap
state, so it should return "doesn't exist" when all the conditions
are not satisfied. I fix it in this patch.
[elder@inktank.com: shortened the commit message]
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Both ceph_osdc_alloc_request() and ceph_osdc_build_request() are
provided an array of ceph osd request operations. Rather than just
passing the number of operations in the array, the caller is
required append an additional zeroed operation structure to signal
the end of the array.
All callers know the number of operations at the time these
functions are called, so drop the silly zero entry and supply that
number directly. As a result, get_num_ops() is no longer needed.
This also means that ceph_osdc_alloc_request() never uses its ops
argument, so that can be dropped.
Also rbd_create_rw_ops() no longer needs to add one to reserve room
for the additional op.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Only one of the two callers of ceph_osdc_alloc_request() provides
page or bio data for its payload. And essentially all that function
was doing with those arguments was assigning them to fields in the
osd request structure.
Simplify ceph_osdc_alloc_request() by having the caller take care of
making those assignments
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The only thing ceph_osdc_alloc_request() really does with the
flags value it is passed is assign it to the newly-created
osd request structure. Do that in the caller instead.
Both callers subsequently call ceph_osdc_build_request(), so have
that function (instead of ceph_osdc_alloc_request()) issue a warning
if a request comes through with neither the read nor write flags set.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The osdc parameter to ceph_calc_raw_layout() is not used, so get rid
of it. Consequently, the corresponding parameter in calc_layout()
becomes unused, so get rid of that as well.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
A snapshot id must be provided to ceph_calc_raw_layout() even though
it is not needed at all for calculating the layout.
Where the snapshot id *is* needed is when building the request
message for an osd operation.
Drop the snapid parameter from ceph_calc_raw_layout() and pass
that value instead in ceph_osdc_build_request().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
ceph_calc_file_object_mapping() takes (among other things) a "file"
offset and length, and based on the layout, determines the object
number ("bno") backing the affected portion of the file's data and
the offset into that object where the desired range begins. It also
computes the size that should be used for the request--either the
amount requested or something less if that would exceed the end of
the object.
This patch changes the input length parameter in this function so it
is used only for input. That is, the argument will be passed by
value rather than by address, so the value provided won't get
updated by the function.
The value would only get updated if the length would surpass the
current object, and in that case the value it got updated to would
be exactly that returned in *oxlen.
Only one of the two callers is affected by this change. Update
ceph_calc_raw_layout() so it records any updated value.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The len argument to ceph_osdc_build_request() is set up to be
passed by address, but that function never updates its value
so there's no need to do this. Tighten up the interface by
passing the length directly.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Since every osd message is now prepared to include trailing data,
there's no need to check ahead of time whether any operations will
make use of the trail portion of the message.
We can drop the second argument to get_num_ops(), and as a result we
can also get rid of op_needs_trail() which is no longer used.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An osd request structure contains an optional trail portion, which
if present will contain data to be passed in the payload portion of
the message containing the request. The trail field is a
ceph_pagelist pointer, and if null it indicates there is no trail.
A ceph_pagelist structure contains a length field, and it can
legitimately hold value 0. Make use of this to change the
interpretation of the "trail" of an osd request so that every osd
request has trailing data, it just might have length 0.
This means we change the r_trail field in a ceph_osd_request
structure from a pointer to a structure that is always initialized.
Note that in ceph_osdc_start_request(), the trail pointer (or now
address of that structure) is assigned to a ceph message's trail
field. Here's why that's still OK (looking at net/ceph/messenger.c):
- What would have resulted in a null pointer previously will now
refer to a 0-length page list. That message trail pointer
is used in two functions, write_partial_msg_pages() and
out_msg_pos_next().
- In write_partial_msg_pages(), a null page list pointer is
handled the same as a message with 0-length trail, and both
result in a "in_trail" variable set to false. The trail
pointer is only used if in_trail is true.
- The only other place the message trail pointer is used is
out_msg_pos_next(). That function is only called by
write_partial_msg_pages() and only touches the trail pointer
if the in_trail value it is passed is true.
Therefore a null ceph_msg->trail pointer is equivalent to a non-null
pointer referring to a 0-length page list structure.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The last two parameters to ceph_osd_build_request() describe the
object id, but the values passed always come from the osd request
structure whose address is also provided. Get rid of those last
two parameters.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reformat __reset_osd() into three distinct blocks of code
handling the three return cases.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This saves us some cycles, but does not affect the placement result at
all.
This corresponds to ceph.git commit 4abb53d4f.
Signed-off-by: Sage Weil <sage@inktank.com>
Add libceph support for a new CRUSH tunable recently added to Ceph servers.
Consider the CRUSH rule
step chooseleaf firstn 0 type <node_type>
This rule means that <n> replicas will be chosen in a manner such that
each chosen leaf's branch will contain a unique instance of <node_type>.
When an object is re-replicated after a leaf failure, if the CRUSH map uses
a chooseleaf rule the remapped replica ends up under the <node_type> bucket
that held the failed leaf. This causes uneven data distribution across the
storage cluster, to the point that when all the leaves but one fail under a
particular <node_type> bucket, that remaining leaf holds all the data from
its failed peers.
This behavior also limits the number of peers that can participate in the
re-replication of the data held by the failed leaf, which increases the
time required to re-replicate after a failure.
For a chooseleaf CRUSH rule, the tree descent has two steps: call them the
inner and outer descents.
If the tree descent down to <node_type> is the outer descent, and the descent
from <node_type> down to a leaf is the inner descent, the issue is that a
down leaf is detected on the inner descent, so only the inner descent is
retried.
In order to disperse re-replicated data as widely as possible across a
storage cluster after a failure, we want to retry the outer descent. So,
fix up crush_choose() to allow the inner descent to return immediately on
choosing a failed leaf. Wire this up as a new CRUSH tunable.
Note that after this change, for a chooseleaf rule, if the primary OSD
in a placement group has failed, choosing a replacement may result in
one of the other OSDs in the PG colliding with the new primary. This
requires that OSD's data for that PG to need moving as well. This
seems unavoidable but should be relatively rare.
This corresponds to ceph.git commit 88f218181a9e6d2292e2697fc93797d0f6d6e5dc.
Signed-off-by: Jim Schutt <jaschut@sandia.gov>
Reviewed-by: Sage Weil <sage@inktank.com>
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.
CC: Sage Weil <sage@inktank.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Sage Weil <sage@inktank.com>
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()
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 <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
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 <ugis22@gmail.com>
Tested-by: Ugis <ugis22@gmail.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-off-by: Sage Weil <sage@inktank.com>
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 <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
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 <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
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
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 <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
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 <sage@inktank.com>
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
...
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 88d19cf379 ("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 10fd48f237
("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 <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Santos <daniel.santos@pobox.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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 <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
If we encounter an invalid (e.g., zeroed) mapping, return an error
and avoid a divide by zero.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Using list_move_tail() instead of list_del() + list_add_tail().
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Sage Weil <sage@inktank.com>
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 <icurt@ixiacom.com>
Signed-off-by: Sage Weil <sage@inktank.com>
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 <bryan@virginia.edu>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
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 <jaschut@sandia.gov>
Reviewed-by: Alex Elder <elder@inktank.com>
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 <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
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 <tnt@246tNt.com>
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
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 tree
There 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()
...
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 <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
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 <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
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 <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
We drop the con mutex when delivering a message. When we retake the
lock, we need to verify we are still in the OPEN state before
preparing to read the next tag, or else we risk stepping on a
connection that has been closed.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Revoke all mon_client messages when we shut down the old connection.
This is mostly moot since we are re-using the same ceph_connection,
but it is cleaner.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
If the connect() call immediately fails such that sock == NULL, we
still need con_close_socket() to reset our socket state to CLOSED.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
There are many (normal) conditions that can lead to us getting
unexpected replies, include cluster topology changes, osd failures,
and timeouts. There's no need to spam the console about it.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Rename flags with CON_FLAG prefix, move the definitions into the c file,
and (better) document their meaning.
Signed-off-by: Sage Weil <sage@inktank.com>
Use a simple set of 6 enumerated values for the socket states (CON_STATE_*)
and use those instead of the state bits. All of the con->state checks are
now under the protection of the con mutex, so this is safe. It also
simplifies many of the state checks because we can check for anything other
than the expected state instead of various bits for races we can think of.
This appears to hold up well to stress testing both with and without socket
failure injection on the server side.
Signed-off-by: Sage Weil <sage@inktank.com>
It is simpler to do this immediately, since we already hold the con mutex.
It also avoids the need to deal with a not-quite-CLOSED socket in con_work.
Signed-off-by: Sage Weil <sage@inktank.com>
Take the con mutex before checking whether the connection is closed to
avoid racing with someone else closing it.
Signed-off-by: Sage Weil <sage@inktank.com>
If we fault on a lossy connection, we should still close the socket
immediately, and do so under the con mutex.
We should also take the con mutex before printing out the state bits in
the debug output.
Signed-off-by: Sage Weil <sage@inktank.com>
This is a trivial fix for the debug output, as it is inconsistent
with the function name so may confuse people when debugging.
[elder@inktank.com: switched to use __func__]
Signed-off-by: Jiaju Zhang <jjzhang@suse.de>
Reviewed-by: Alex Elder <elder@inktank.com>
We exponentially back off when we encounter connection errors. If several
errors accumulate, we will eventually wait ages before even trying to
reconnect.
Fix this by resetting the backoff counter after a successful negotiation/
connection with the remote node. Fixes ceph issue #2802.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Take the con mutex while we are initiating a ceph open. This is necessary
because the may have previously been in use and then closed, which could
result in a racing workqueue running con_work().
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Previously, we were opportunistically initializing the bio_iter if it
appeared to be uninitialized in the middle of the read path. The problem
is that a sequence like:
- start reading message
- initialize bio_iter
- read half a message
- messenger fault, reconnect
- restart reading message
- ** bio_iter now non-NULL, not reinitialized **
- read past end of bio, crash
Instead, initialize the bio_iter unconditionally when we allocate/claim
the message for read.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
The linger op registration (i.e., watch) modifies the object state. As
such, the OSD will reply with success if it has already applied without
doing the associated side-effects (setting up the watch session state).
If we lose the ACK and resubmit, we will see success but the watch will not
be correctly registered and we won't get notifies.
To fix this, always resubmit the linger op with a new tid. We accomplish
this by re-registering as a linger (i.e., 'registered') if we are not yet
registered. Then the second loop will treat this just like a normal
case of re-registering.
This mirrors a similar fix on the userland ceph.git, commit 5dd68b95, and
ceph bug #2796.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Hold the mutex while twiddling all of the state bits to avoid possible
races. While we're here, make not of why we cannot close the socket
directly.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
We need to set error_msg to something useful before calling ceph_fault();
do so here for try_{read,write}(). This is more informative than
libceph: osd0 192.168.106.220:6801 (null)
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
The server side recently added support for tuning some magic
crush variables. Decode these variables if they are present, or use the
default values if they are not present.
Corresponds to ceph.git commit 89af369c25f274fe62ef730e5e8aad0c54f1e5a5.
Signed-off-by: caleb miles <caleb.miles@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
This is simply cleanup that will keep things more closely synced with the
userland code.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Add an atomic variable 'stopping' as flag in struct ceph_messenger,
set this flag to 1 in function ceph_destroy_client(), and add the condition code
in function ceph_data_ready() to test the flag value, if true(1), just return.
Signed-off-by: Guanjun He <gjhe@suse.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Alex Elder