[PATCH 0/5] fs, xfs atomic_t to refcount_t conversions version 2

From: Elena Reshetova
Date: Wed Mar 01 2017 - 08:43:44 EST


changes in v2:

* removed two patches that actually caused problems in testing and
there didn't seem to be a resonable way to convert them to refcount_t
based on all the triggered issues.
* run xfstests with TEST and SCRATCH partitions enabled, XFS_DEBUG on,
and WARNs on refcount_t API on. No issues found in the log upon execution.
Some random test failures (based on different runs) and stress tests do not always
pass, but again, no issues on refcounts noticed anywhere.


Now when new refcount_t type and API are finally merged
(see include/linux/refcount.h), the following
patches convert various refcounters in the fs/xfs susystem from atomic_t
to refcount_t. By doing this we prevent intentional or accidental
underflows or overflows that can led to use-after-free vulnerabilities.

The below patches are fully independent and can be cherry-picked separately.
Since we convert all kernel subsystems in the same fashion, resulting
in about 300 patches, we have to group them for sending at least in some
fashion to be manageable. Please excuse the long cc list.

Elena Reshetova (5):
fs, xfs: convert xfs_bui_log_item.bui_refcount from atomic_t to
refcount_t
fs, xfs: convert xfs_efi_log_item.efi_refcount from atomic_t to
refcount_t
fs, xfs: convert xlog_ticket.t_ref from atomic_t to refcount_t
fs, xfs: convert xfs_cui_log_item.cui_refcount from atomic_t to
refcount_t
fs, xfs: convert xfs_rui_log_item.rui_refcount from atomic_t to
refcount_t

fs/xfs/xfs_bmap_item.c | 4 ++--
fs/xfs/xfs_bmap_item.h | 4 +++-
fs/xfs/xfs_extfree_item.c | 4 ++--
fs/xfs/xfs_extfree_item.h | 4 +++-
fs/xfs/xfs_log.c | 10 +++++-----
fs/xfs/xfs_log_priv.h | 4 +++-
fs/xfs/xfs_refcount_item.c | 4 ++--
fs/xfs/xfs_refcount_item.h | 4 +++-
fs/xfs/xfs_rmap_item.c | 4 ++--
fs/xfs/xfs_rmap_item.h | 4 +++-
10 files changed, 28 insertions(+), 18 deletions(-)

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2.7.4