os: rename get_*() -> decode_*()

These methods have side-effects: they move the decode iterator *and*
return a value.  Rename them to avoid confusion with typical get_*
accessors.

Signed-off-by: Sage Weil <sage@inktank.com>
doc: Descrption => Description
Correct spelling error.

Signed-off-by: Kevin Dalley <kevin@kelphead.org>
Merge pull request #1928 from nereocystis/pool-pg-fix-spelling

doc: Descrption => Description

Reviewed-by: Loic Dachary <loic@dachary.org>
XfsFileStoreBackend: nuke redundant goto in set_extsize()

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
XfsFileStoreBackend: call ioctl(XFS_IOC_FSSETXATTR) less often

No need to call ioctl(XFS_IOC_FSSETXATTR) if extsize is already set to
the value we want or if any extents are allocated - XFS will refuse to
change extsize in that's the case.

Fixes: #8241
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Merge pull request #1922 from ceph/wip-os-rename

os: rename get_*() -> decode_*()

Reviewed-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@cloudwatt.com>
Merge pull request #1930 from ceph/wip-set-extsize-fix

Wip set extsize fix

Backport: firefly
Reviewed-by: Sage Weil <sage@inktank.com>