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authorElena Reshetova <elena.reshetova@intel.com>2017-03-03 10:55:23 +0200
committerDavid Sterba <dsterba@suse.com>2017-04-18 14:07:24 +0200
commit186debd6ede29da9d51cffdb93cadee66e4e1e23 (patch)
tree76a630c3cb8e25d593fc59d70175d9ada2b25e01 /fs/btrfs
parent6f615018b35fb5ea1ce49673079fc637a0b6be70 (diff)
btrfs: convert scrub_block.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.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index c9406bf302b8..d2c35848e61d 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -112,7 +112,7 @@ struct scrub_block {
struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
int page_count;
atomic_t outstanding_pages;
- atomic_t refs; /* free mem on transition to zero */
+ refcount_t refs; /* free mem on transition to zero */
struct scrub_ctx *sctx;
struct scrub_parity *sparity;
struct {
@@ -1998,12 +1998,12 @@ static int scrub_checksum_super(struct scrub_block *sblock)
static void scrub_block_get(struct scrub_block *sblock)
{
- atomic_inc(&sblock->refs);
+ refcount_inc(&sblock->refs);
}
static void scrub_block_put(struct scrub_block *sblock)
{
- if (atomic_dec_and_test(&sblock->refs)) {
+ if (refcount_dec_and_test(&sblock->refs)) {
int i;
if (sblock->sparity)
@@ -2255,7 +2255,7 @@ static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
/* one ref inside this function, plus one for each page added to
* a bio later on */
- atomic_set(&sblock->refs, 1);
+ refcount_set(&sblock->refs, 1);
sblock->sctx = sctx;
sblock->no_io_error_seen = 1;
@@ -2555,7 +2555,7 @@ static int scrub_pages_for_parity(struct scrub_parity *sparity,
/* one ref inside this function, plus one for each page added to
* a bio later on */
- atomic_set(&sblock->refs, 1);
+ refcount_set(&sblock->refs, 1);
sblock->sctx = sctx;
sblock->no_io_error_seen = 1;
sblock->sparity = sparity;