Messages in this thread Patch in this message | | | From | Liu Song <> | Subject | [PATCH v2] ubifs: remove unnecessary check in ubifs_log_start_commit | Date | Fri, 24 Aug 2018 09:15:45 +0800 |
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In ubifs_log_start_commit, the value of c->lhead_offs is zero or set to zero by code bellow.
/* Switch to the next log LEB */ if (c->lhead_offs) { c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum); ubifs_assert(c->lhead_lnum != c->ltail_lnum); c->lhead_offs = 0; }
The value of 'len' can not exceed 'max_len' which assigned value by code bellow.
max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ;
The value of c->lhead_offs changed by code bellow and cannot exceed 'max_len'.
c->lhead_offs += len; if (c->lhead_offs == c->leb_size) { c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum); c->lhead_offs = 0; }
Usually, the size of PEB is between 64KB and 256KB. So the value of c->lhead_offs is far less than c->leb_size. The check 'if (c->lhead_offs == c->leb_size)' could never to be true.
Signed-off-by: Liu Song <liu.song11@zte.com.cn> Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn> --- v2: Improve description and code as suggestted by Richard.
fs/ubifs/log.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c index 7cffa12..78afb78 100644 --- a/fs/ubifs/log.c +++ b/fs/ubifs/log.c @@ -427,10 +427,7 @@ int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum) *ltail_lnum = c->lhead_lnum; c->lhead_offs += len; - if (c->lhead_offs == c->leb_size) { - c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum); - c->lhead_offs = 0; - } + ubifs_assert(c->lhead_offs < c->leb_size); remove_buds(c); -- 2.1.0.GIT
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