Commit Graph

323402 Commits

Author SHA1 Message Date
Alex Elder ab60b16d3c libceph: move linger requests sooner in kick_requests()
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>
2012-12-27 20:27:04 -06:00
Alex Elder c3e946ce72 rbd: get rid of rbd_{get,put}_dev()
The functions rbd_get_dev() and rbd_put_dev() are trivial wrappers
that add no value, and their existence suggests they may do more
than what they do.

Get rid of them.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
2012-12-20 10:56:44 -06:00
Alex Elder c89ce05e0c libceph: register request before unregister linger
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>
2012-12-20 10:56:39 -06:00
Alex Elder a978fa20fb libceph: don't use rb_init_node() in ceph_osdc_alloc_request()
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>
2012-12-20 10:56:33 -06:00
Alex Elder 3ee5234df6 libceph: init event->node in ceph_osdc_create_event()
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>
2012-12-20 10:56:28 -06:00
Alex Elder f407731d12 libceph: init osd->o_node in create_osd()
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>
2012-12-20 10:56:21 -06:00
Alex Elder 28362986f8 libceph: report connection fault with warning
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>
2012-12-20 10:56:13 -06:00
Alex Elder 7bb21d68c5 libceph: socket can close in any connection state
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>
2012-12-17 12:07:32 -06:00
Alex Elder b8f5c6edca rbd: don't use ENOTSUPP
ENOTSUPP is not a standard errno (it shows up as "Unknown error 524"
in an error message).  This is what was getting produced when the
the local rbd code does not implement features required by a
discovered rbd image.

Change the error code returned in this case to ENXIO.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-17 12:07:32 -06:00
Alex Elder 61c7403562 rbd: remove linger unconditionally
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>
2012-12-17 12:07:31 -06:00
Alex Elder 2fd82b9e92 rbd: get rid of RBD_MAX_SEG_NAME_LEN
RBD_MAX_SEG_NAME_LEN represents the maximum length of an rbd object
name (i.e., one of the objects providing storage backing an rbd
image).

Another symbol, MAX_OBJ_NAME_SIZE, is used in the osd client code to
define the maximum length of any object name in an osd request.

Right now they disagree, with RBD_MAX_SEG_NAME_LEN being too big.

There's no real benefit at this point to defining the rbd object
name length limit separate from any other object name, so just
get rid of RBD_MAX_SEG_NAME_LEN and use MAX_OBJ_NAME_SIZE in its
place.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-17 08:37:29 -06:00
Alex Elder 685a7555ca libceph: avoid using freed osd in __kick_osd_requests()
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>
2012-12-17 08:37:23 -06:00
Alex Elder 7d5f24812b ceph: don't reference req after put
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>
2012-12-17 08:37:19 -06:00
Alex Elder 42382b709b rbd: do not allow remove of mounted-on image
There is no check in rbd_remove() to see if anybody holds open the
image being removed.  That's not cool.

Add a simple open count that goes up and down with opens and closes
(releases) of the device, and don't allow an rbd image to be removed
if the count is non-zero.

Protect the updates of the open count value with ctl_mutex to ensure
the underlying rbd device doesn't get removed while concurrently
being opened.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-17 08:36:59 -06:00
David Zafman 8884d53dd6 libceph: Unlock unprocessed pages in start_read() error path
Function start_read() can get an error before processing all pages.
It must not only release the remaining pages, but unlock them too.

This fixes http://tracker.newdream.net/issues/3370

Signed-off-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2012-12-13 08:13:09 -06:00
Yan, Zheng 0e5e1774a9 ceph: call handle_cap_grant() for cap import message
If client sends cap message that requests new max size during
exporting caps, the exporting MDS will drop the message quietly.
So the client may wait for the reply that updates the max size
forever. call handle_cap_grant() for cap import message can
avoid this issue.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:08 -06:00
Yan, Zheng a85f50b6ef ceph: Fix __ceph_do_pending_vmtruncate
we should set i_truncate_pending to 0 after page cache is truncated
to i_truncate_size

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:08 -06:00
Yan, Zheng 0685235ffd ceph: Don't add dirty inode to dirty list if caps is in migration
Add dirty inode to cap_dirty_migrating list instead, this can avoid
ceph_flush_dirty_caps() entering infinite loop.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:08 -06:00
Yan, Zheng ed75ec2cd1 ceph: Fix infinite loop in __wake_requests
__wake_requests() will enter infinite loop if we use it to wake
requests in the session->s_waiting list. __wake_requests() deletes
requests from the list and __do_request() adds requests back to
the list.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:07 -06:00
Yan, Zheng 5e62ad3015 ceph: Don't update i_max_size when handling non-auth cap
The cap from non-auth mds doesn't have a meaningful max_size value.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:07 -06:00
Joe Perches d2cc4dde92 bdi_register: add __printf verification, fix arg mismatch
__printf is useful to verify format and arguments.

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2012-12-13 08:13:07 -06:00
Sage Weil 83aff95eb9 libceph: remove 'osdtimeout' option
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>
2012-12-13 08:13:06 -06:00
Cyril Roelandt cfc84c9f73 ceph: fix dentry reference leak in ceph_encode_fh().
dput() was not called in the error path.

Signed-off-by: Cyril Roelandt <tipecaml@gmail.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2012-12-13 08:13:06 -06:00
Sage Weil 22cddde104 ceph: Fix i_size update race
ceph_aio_write() has an optimization that marks cap EPH_CAP_FILE_WR
dirty before data is copied to page cache and inode size is updated.
If ceph_check_caps() flushes the dirty cap before the inode size is
updated, MDS can miss the new inode size. The fix is move
ceph_{get,put}_cap_refs() into ceph_write_{begin,end}() and call
__ceph_mark_dirty_caps() after inode size is updated.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-11-05 11:07:23 -08:00
Yan, Zheng 4d1d0534f5 ceph: Hold caps_list_lock when adjusting caps_{use, total}_count
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-11-04 03:08:24 -08:00
Alex Elder 9e15b77d9a rbd: get additional info in parent spec
When a layered rbd image has a parent, that parent is identified
only by its pool id, image id, and snapshot id.  Images that have
been mapped also record *names* for those three id's.

Add code to look up these names for parent images so they match
mapped images more closely.  Skip doing this for an image if it
already has its pool name defined (this will be the case for images
mapped by the user).

It is possible that an the name of a parent image can't be
determined, even if the image id is valid.  If this occurs it
does not preclude correct operation, so don't treat this as
an error.

On the other hand, defined pools will always have both an id and a
name.   And any snapshot of an image identified as a parent for a
clone image will exist, and will have a name (if not it indicates
some other internal error).  So treat failure to get these bits
of information as errors.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder 72afc71ffc libceph: define ceph_pg_pool_name_by_id()
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>
2012-11-01 07:55:42 -05:00
Alex Elder 86b00e0da6 rbd: get parent spec for version 2 images
Add support for getting the the information identifying the parent
image for rbd images that have them.  The child image holds a
reference to its parent image specification structure.  Create a new
entry "parent" in /sys/bus/rbd/image/N/ to report the identifying
information for the parent image, if any.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder a92ffdf8a9 rbd: allow null image name
Format 2 parent images are partially identified by their image id,
but it may not be possible to determine their image name.  The name
is not strictly needed for correct operation, so we won't be
treating it as an error if we don't know it.  Handle this case
gracefully in rbd_name_show().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder 2c0d0a10ea rbd: allow null image name
We will know the image id for format 2 parent images, but won't
initially know its image name.  Avoid making the query for an image
id in rbd_dev_image_id() if it's already known.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder 83a0626362 rbd: encapsulate last part of probe
Group the activities that now take place after an rbd_dev_probe()
call into a single function, and move the call to that function
into rbd_dev_probe() itself.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder c53d589337 rbd: define rbd_dev_{create,destroy}() helpers
Encapsulate the creation/initialization and destruction of rbd
device structures.  The rbd_client and the rbd_spec structures
provided on creation hold references whose ownership is transferred
to the new rbd_device structure.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder bd4ba6554d rbd: consolidate rbd_dev init in rbd_add()
Group the allocation and initialization of fields of the rbd device
structure created in rbd_add().  Move the grouped code down later in
the function, just prior to the call to rbd_dev_probe().  This is
for the most part simple code movement.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder 9d3997fdf4 rbd: don't pass rbd_dev to rbd_get_client()
The only reason rbd_dev is passed to rbd_get_client() is so its
rbd_client field can get assigned.  Instead, just return the
rbd_client pointer as a result and have the caller do the
assignment.

Change rbd_put_client() so it takes an rbd_client structure,
so follows the more typical symmetry with rbd_get_client().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder 859c31df9c rbd: fill rbd_spec in rbd_add_parse_args()
Pass the address of an rbd_spec structure to rbd_add_parse_args().
Use it to hold the information defining the rbd image to be mapped
in an rbd_add() call.

Use the result in the caller to initialize the rbd_dev->id field.

This means rbd_dev is no longer needed in rbd_add_parse_args(),
so get rid of it.

Now that this transformation of rbd_add_parse_args() is complete,
correct and expand on the its header documentation to reflect the
new reality.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder 8b8fb99c5c rbd: add reference counting to rbd_spec
With layered images we'll share rbd_spec structures, so add a
reference count to it.  It neatens up some code also.

A silly get/put pair is added to the alloc routine just to avoid
"defined but not used" warnings.  It will go away soon.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:41 -05:00
Alex Elder 0d7dbfce9d rbd: define image specification structure
Group the fields that uniquely specify an rbd image into a new
reference-counted rbd_spec structure.  This structure will be used
to describe the desired image when mapping an image, and when
probing parent images in layered rbd devices.  Replace the set of
fields in the rbd device structure with a pointer to a dynamically
allocated rbd_spec.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:30 -05:00
Alex Elder dc79b113d6 rbd: have rbd_add_parse_args() return error
Change the interface to rbd_add_parse_args() so it returns an
error code rather than a pointer.  Return the ceph_options result
via a pointer whose address is passed as an argument.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:30 -05:00
Alex Elder 4e9afeba7a rbd: pass and populate rbd_options structure
Have the caller pass the address of an rbd_options structure to
rbd_add_parse_args(), to be initialized with the information
gleaned as a result of the parse.

I know, this is another near-reversal of a recent change...

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:29 -05:00
Alex Elder 819d52bf72 rbd: remove snap_name arg from rbd_add_parse_args()
The snapshot name returned by rbd_add_parse_args() just gets saved
in the rbd_dev eventually.  So just do that inside that function and
do away with the snap_name argument, both in rbd_add_parse_args()
and rbd_dev_set_mapping().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:29 -05:00
Alex Elder f28e565a1b rbd: remove options args from rbd_add_parse_args()
They "options" argument to rbd_add_parse_args() (and it's partner
options_size) is now only needed within the function, so there's no
need to have the caller allocate and pass the options buffer.  Just
allocate the options buffer within the function using dup_token().

Also distinguish between failures due to failed memory allocation
and failing because a required argument was missing.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:29 -05:00
Alex Elder e5c3553404 rbd: get rid of snap_name_len
The value returned in the "snap_name_len" argument to
rbd_add_parse_args() is never actually used, so get rid of it.

The snap_name_len recorded in rbd_dev_v2_snap_name() is not
useful either, so get rid of that too.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:29 -05:00
Alex Elder 0ddebc0c6c rbd: do all argument parsing in one place
This patch makes rbd_add_parse_args() be the single place all
argument parsing occurs for an image map request:
    - Move the ceph_parse_options() call into that function
    - Use local variables rather than parameters to hold the list
      of monitor addresses supplied
    - Rather than returning it, pass the snapshot name (and its
      length) back via parameters
    - Have the function return a ceph_options structure pointer

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:29 -05:00
Alex Elder 78cea76e05 rbd: move ceph_parse_options() call up
Move option parsing out of rbd_get_client() and into its caller.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:29 -05:00
Alex Elder daba5fdb4c rbd: rename snap_exists field
A Boolean field "snap_exists" in an rbd mapping is used to indicate
whether a mapped snapshot has been removed from an image's snapshot
context, to stop sending requests for that snapshot as soon as we
know it's gone.

Generalize the interpretation of this field so it applies to
non-snapshot (i.e. "head") mappings.  That is, define its value
to be false until the mapping has been set, and then define it to be
true for both snapshot mappings or head mappings.

Rename the field "exists" to reflect the broader interpretation.
The rbd_mapping structure is on its way out, so move the field
back into the rbd_device structure.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:29 -05:00
Alex Elder 971f839a76 rbd: move snap info out of rbd_mapping struct
Moving the snap_id and snap_name fields into the separate
rbd_mapping structure was misguided.  (And in time, perhaps
we'll do away with that structure altogether...)

Move these fields back into struct rbd_device.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:29 -05:00
Alex Elder 86992098e7 rbd: make pool_id a 64 bit value
If a format 2 image has a parent, its pool id will be specified
using a 64-bit value.  Change the pool id we save for an image to
match that.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:29 -05:00
Alex Elder 41f38c2b2f rbd: remove snapshots on error in rbd_add()
If rbd_dev_snaps_update() has ever been called for an rbd device
structure there could be snapshot structures on its snaps list.
In rbd_add(), this function is called but a subsequent error
path neglected to clean up any of these snapshots.

Add a call to rbd_remove_all_snaps() in the appropriate spot to
remedy this.  Change a couple of error labels to be a little
clearer while there.

Drop the leading underscores from the function name; there's nothing
special about that function that they might signify.  As suggested
in review, the leading underscores in __rbd_remove_snap_dev() have
been removed as well.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:28 -05:00
Alex Elder f7760dad28 rbd: simplify rbd_rq_fn()
When processing a request, rbd_rq_fn() makes clones of the bio's in
the request's bio chain and submits the results to osd's to be
satisfied.  If a request bio straddles the boundary between objects
backing the rbd image, it must be represented by two cloned bio's,
one for the first part (at the end of one object) and one for the
second (at the beginning of the next object).

This has been handled by a function bio_chain_clone(), which
includes an interface only a mother could love, and which has
been found to have other problems.

This patch defines two new fairly generic bio functions (one which
replaces bio_chain_clone()) to help out the situation, and then
revises rbd_rq_fn() to make use of them.

First, bio_clone_range() clones a portion of a single bio, starting
at a given offset within the bio and including only as many bytes
as requested.  As a convenience, a request to clone the entire bio
is passed directly to bio_clone().

Second, bio_chain_clone_range() performs a similar function,
producing a chain of cloned bio's covering a sub-range of the
source chain.  No bio_pair structures are used, and if successful
the result will represent exactly the specified range.

Using bio_chain_clone_range() makes bio_rq_fn() a little easier
to understand, because it avoids the need to pass very much
state information between consecutive calls.  By avoiding the need
to track a bio_pair structure, it also eliminates the problem
described here:  http://tracker.newdream.net/issues/2933

Note that a block request (and therefore the complete length of
a bio chain processed in rbd_rq_fn()) is an unsigned int, while
the result of rbd_segment_length() is u64.  This change makes
this range trunctation explicit, and trips a bug if the the
segment boundary is too far off.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-10-30 08:34:28 -05:00
Sage Weil 0ed7285e00 libceph: fix osdmap decode error paths
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>
2012-10-30 08:21:05 -05:00