dm verity fec: fix bufio leaks

Buffers read through dm_bufio_read() were not released in all code paths.

Fixes: a739ff3f543a ("dm verity: add support for forward error correction")
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c
index c3cc04d89524c6263d316aeec1611f70eccad0e1..78f36012eacacb3ca16888b880c0416f8234a14d 100644 (file)
--- a/drivers/md/dm-verity-fec.c
+++ b/drivers/md/dm-verity-fec.c
@@ -146,8 +146,6 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio,
                block = fec_buffer_rs_block(v, fio, n, i);
                res = fec_decode_rs8(v, fio, block, &par[offset], neras);
                if (res < 0) {
-                       dm_bufio_release(buf);
-
                        r = res;
                        goto error;
                }
@@ -172,6 +170,8 @@ static int fec_decode_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio,
 done:
        r = corrected;
 error:
+       dm_bufio_release(buf);
+
        if (r < 0 && neras)
                DMERR_LIMIT("%s: FEC %llu: failed to correct: %d",
                            v->data_dev->name, (unsigned long long)rsb, r);
@@ -269,7 +269,7 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
                                          &is_zero) == 0) {
                        /* skip known zero blocks entirely */
                        if (is_zero)
-                               continue;
+                               goto done;
 
                        /*
                         * skip if we have already found the theoretical