librbd: fix coverity warnings for AioCompletions

CID 717220: Uninitialized pointer field (UNINIT_CTOR)
At (4): Non-static class member "aio_type" is not initialized in this
constructor nor in any functions that it calls.

CID 717221: Uninitialized pointer field (UNINIT_CTOR)
At (2): Non-static class member "m_req" is not initialized in this
constructor nor in any functions that it calls.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
librbd: init everything in default AioRequest constructors

CID 717222: Uninitialized pointer field (UNINIT_CTOR)
At (16): Non-static class member "m_hide_enoent" is not initialized
in this constructor nor in any functions that it calls.

CID 717223: Uninitialized scalar field (UNINIT_CTOR)
At (4): Non-static class member "m_has_parent" is not initialized in
this constructor nor in any functions that it calls.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
librbd: initialize on-disk header in ImageCtx ctor

CID 717224: Uninitialized scalar field (UNINIT_CTOR)
At (26): Non-static class member field "header.snaps" is not
initialized in this constructor nor in any functions that it calls.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
librbd: init m_req in LibrbdWriteback::C_Read ctor

CID 717225: Uninitialized pointer field (UNINIT_CTOR)
At (2): Non-static class member "m_req" is not initialized in this
constructor nor in any functions that it calls.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
librbd: init cookie in WatchCtx ctor

CID 717226: Uninitialized scalar field (UNINIT_CTOR)
At (2): Non-static class member "cookie" is not initialized in this
constructor nor in any functions that it calls.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
librbd: use 64-bits to shift order

Order is never actually this high currently, but it be via librbd.

CID 716937: Overflowed return value (INTEGER_OVERFLOW)
At (3): Overflowed or truncated value (or a value computed from an
overflowed or truncated value) "offset" used as return value.

CID 717012: Unintentional integer overflow (OVERFLOW_BEFORE_WIDEN)
At (1): Potentially overflowing expression "1 << obj_order" with type
"int" (32 bits, signed) is evaluated using 32-bit arithmetic before
being used in a context which expects an expression of type "uint64_t"
(64 bits, unsigned). To avoid overflow, cast the left operand to
"uint64_t" before performing the left shift.

CID 717011: Unintentional integer overflow (OVERFLOW_BEFORE_WIDEN)
At (1): Potentially overflowing expression "1 << order" with type
"int" (32 bits, signed) is evaluated using 32-bit arithmetic before
being used in a context which expects an expression of type "uint64_t"
(64 bits, unsigned). To avoid overflow, cast the left operand to
"uint64_t" before performing the left shift.

CID 717013: Unintentional integer overflow (OVERFLOW_BEFORE_WIDEN)
At (1): Potentially overflowing expression "1 << order" with type
"int" (32 bits, signed) is evaluated using 32-bit arithmetic before
being used in a context which expects an expression of type "uint64_t"
(64 bits, unsigned). To avoid overflow, cast the left operand to
"uint64_t" before performing the left shift.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
librbd: don't allow order to be more than 64

Otherwise it will overflow a uint64_t when shifting.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
librbd: fix list for more than 1024 format 2 images

r was not being set in the loop.

CID 716936: Infinite loop (INFINITE_LOOP)
At (1): Top of the loop.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
rbd: make sure we have a device before trying to unmap

CID 717444: Explicit null dereferenced (FORWARD_NULL)
 At (48): Passing null pointer "devpath" to function
"do_kernel_rm(char const *)", which dereferences it.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
librados: init everything in default IoCtxImpl ctor

CID 717219: Uninitialized pointer field (UNINIT_CTOR)
At (14): Non-static class member "objecter" is not initialized in this
constructor nor in any functions that it calls.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
librados: fix use without NULL check in rados_pool_list

CID 716911: Dereference after null check (FORWARD_NULL)
At (5): Passing null pointer "b" to function "strncat(char *, char
const *, size_t)", which dereferences it. (The dereference is assumed
on the basis of the 'nonnull' parameter attribute.)

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
config: remove useless NULL check

malloc will throw std::bad_alloc, not return NULL.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
librados: always free buffer allocated by md_config_t::_get_val

CID 717083: Resource leak (RESOURCE_LEAK)
At (3): Variable "str" going out of scope leaks the storage it points
to.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
secret: close fd on error

CID 717079: Resource leak (RESOURCE_LEAK)
At (6): Handle variable "fd" going out of scope leaks the handle.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
rbd: fix leak of fd when importing an image from a file

CID 719579: Resource leak (RESOURCE_LEAK)
At (7): Handle variable "fd" going out of scope leaks the handle.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
rbd: fix leak of fd on error when reading an entire file

CID 717100: Resource leak (RESOURCE_LEAK)
At (6): Handle variable "fd" going out of scope leaks the handle.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
rbd: fix leak of dir handle in get_rbd_seq

CID 717098: Resource leak (RESOURCE_LEAK)
At (6): Variable "device_dir" going out of scope leaks the storage it
points to.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>