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| author | Elena Reshetova <elena.reshetova@intel.com> | 2017-03-03 10:55:25 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2017-04-18 14:07:24 +0200 |
| commit | 99f4cdb16f80e1b30392b479d852036f87394b20 (patch) | |
| tree | 77f2185f29619dc29773fa54ed7a7d2b12cfb614 /fs/btrfs | |
| parent | 78a764504d1e11411bec0e068c5d9e0a417aff08 (diff) | |
| download | linux-99f4cdb16f80e1b30392b479d852036f87394b20.tar.gz linux-99f4cdb16f80e1b30392b479d852036f87394b20.tar.bz2 linux-99f4cdb16f80e1b30392b479d852036f87394b20.zip | |
btrfs: convert scrub_ctx.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/scrub.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 8130ab11821f..6ba0c9ddf777 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -202,7 +202,7 @@ struct scrub_ctx { * doesn't free the scrub context before or while the workers are * doing the wakeup() call. */ - atomic_t refs; + refcount_t refs; }; struct scrub_fixup_nodatasum { @@ -305,7 +305,7 @@ static void scrub_put_ctx(struct scrub_ctx *sctx); static void scrub_pending_bio_inc(struct scrub_ctx *sctx) { - atomic_inc(&sctx->refs); + refcount_inc(&sctx->refs); atomic_inc(&sctx->bios_in_flight); } @@ -356,7 +356,7 @@ static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx) { struct btrfs_fs_info *fs_info = sctx->fs_info; - atomic_inc(&sctx->refs); + refcount_inc(&sctx->refs); /* * increment scrubs_running to prevent cancel requests from * completing as long as a worker is running. we must also @@ -447,7 +447,7 @@ static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx) static void scrub_put_ctx(struct scrub_ctx *sctx) { - if (atomic_dec_and_test(&sctx->refs)) + if (refcount_dec_and_test(&sctx->refs)) scrub_free_ctx(sctx); } @@ -462,7 +462,7 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace) sctx = kzalloc(sizeof(*sctx), GFP_KERNEL); if (!sctx) goto nomem; - atomic_set(&sctx->refs, 1); + refcount_set(&sctx->refs, 1); sctx->is_dev_replace = is_dev_replace; sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO; sctx->curr = -1; |