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: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage 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continue to be used even when it's no longer valid.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: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage 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: NAlex Elder <elder@inktank.com>
Reviewed-off-by: NSage Weil <sage@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

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/3370Signed-off-by: NDavid Zafman <david.zafman@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

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

we should set i_truncate_pending to 0 after page cache is truncated
to i_truncate_size
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: NSage Weil <sage@inktank.com>

Add dirty inode to cap_dirty_migrating list instead, this can avoid
ceph_flush_dirty_caps() entering infinite loop.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: NSage Weil <sage@inktank.com>

__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: NYan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: NSage Weil <sage@inktank.com>

The cap from non-auth mds doesn't have a meaningful max_size value.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: NSage Weil <sage@inktank.com>

__printf is useful to verify format and arguments.
Signed-off-by: NJoe Perches <joe@perches.com>
Reviewed-by: NAlex Elder <elder@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: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

dput() was not called in the error path.
Signed-off-by: NCyril Roelandt <tipecaml@gmail.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

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

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

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Move option parsing out of rbd_get_client() and into its caller.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

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: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh 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: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>