FileJournal: check return value of lseek in write_fd

CID 716859: Other violation (CHECKED_RETURN)At (1): Calling function
"lseek64(this->fd, pos, 0)" without checking return value. This library
function may fail and return an error code.

Signed-off-by: Samuel Just <sam.just@inktank.com>
FileJournal: uninit var in ctor FileJournal

CID 717332: Uninitialized pointer field (UNINIT_CTOR)At (12): Non-static class
member field "iocb.aio_fildes" is not initialized in this constructor nor in
any functions that it calls.

Signed-off-by: Samuel Just <sam.just@inktank.com>
FileJournal: uninit var in ctor aio_ctx FileJournal

CID 717333: Uninitialized pointer field (UNINIT_CTOR)At (2): Non-static class
member "aio_ctx" is not initialized in this constructor nor in any functions
that it calls.

Signed-off-by: Samuel Just <sam.just@inktank.com>
FileStore: fix statfs,fstatfs,fstat ret val checks

CID 716863: Other violation (CHECKED_RETURN)At (20): Calling function
"fstat(basedir_fd, &basest)" without checking return value. This library
function may fail and return an error code.

Signed-off-by: Samuel Just <sam.just@inktank.com>
FileStore: fix filedescriptor leak in mkfs

CID 717091: Resource leak (RESOURCE_LEAK)At (39): Handle variable "fd" going
out of scope leaks the handle.

Signed-off-by: Samuel Just <sam.just@inktank.com>
FileStore: fix leaked fd and check lseek in _test_fiemap

CID 716861: Other violation (CHECKED_RETURN)At (3): Calling function "lseek(fd,
off, 0)" without checking return value. This library function may fail and
return an error code.

CID 717090: Resource leak (RESOURCE_LEAK)At (10): Handle variable "fd" going
out of scope leaks the handle.

Signed-off-by: Samuel Just <sam.just@inktank.com>
FileStore: fix fd and tmpfd leaks in _detect_fs()

CID 717088: Resource leak (RESOURCE_LEAK)At (11): Handle variable "tmpfd" going
out of scope leaks the handle.

Signed-off-by: Samuel Just <sam.just@inktank.com>
FileStore: don't leak r in mount

ID 717092: Resource leak (RESOURCE_LEAK)At (40): Handle variable "r" going out
of scope leaks the handle.

Signed-off-by: Samuel Just <sam.just@inktank.com>
FileStore: fix omap_store and dbomap leaks in mount

CID 717093: Resource leak (RESOURCE_LEAK)At (48): Variable "omap_store" going
out of scope leaks the storage it points to.

Signed-off-by: Samuel Just <sam.just@inktank.com>
FileStore: uninit var in ctor OpSequencer::parent

CID 717334: Uninitialized pointer field (UNINIT_CTOR)At (2): Non-static class
member "parent" is not initialized in this constructor nor in any functions
that it calls.

Signed-off-by: Samuel Just <sam.just@inktank.com>
FlatIndex: terminate dir_name buffer passed to strncpy

CID 716836: Buffer not null terminated (BUFFER_SIZE_WARNING)At (1): Calling
strncpy with a maximum size argument of 4096 bytes on destination array
"dir_name" of size 4096 bytes might leave the destination string unterminated.

Signed-off-by: Samuel Just <sam.just@inktank.com>
JournalingObjectStore: lock journal_lock at top of journal_replay

CID 716968: Data race condition (MISSING_LOCK)At (6): Accessing "this->op_seq"
("JournalingObjectStore.op_seq") requires the "Mutex._m" lock.

Doesn't really matter, but this should satisfy coverity.

Signed-off-by: Samuel Just <sam.just@inktank.com>