diff options
| author | Artem Bityutskiy <artem.bityutskiy@linux.intel.com> | 2014-07-16 15:22:29 +0300 |
|---|---|---|
| committer | Artem Bityutskiy <artem.bityutskiy@linux.intel.com> | 2014-09-08 15:55:28 +0300 |
| commit | ba29e721eb2df6df8f33c1f248388bb037a47914 (patch) | |
| tree | e10db004cdbc4027d0046838ec9bee534a09f2c1 /fs/ubifs/log.c | |
| parent | 052c28073ff26f771d44ef33952a41d18dadd255 (diff) | |
| download | lwn-ba29e721eb2df6df8f33c1f248388bb037a47914.tar.gz lwn-ba29e721eb2df6df8f33c1f248388bb037a47914.zip | |
UBIFS: fix free log space calculation
Hu (hujianyang <hujianyang@huawei.com>) discovered an issue in the
'empty_log_bytes()' function, which calculates how many bytes are left in the
log:
"
If 'c->lhead_lnum + 1 == c->ltail_lnum' and 'c->lhead_offs == c->leb_size', 'h'
would equalent to 't' and 'empty_log_bytes()' would return 'c->log_bytes'
instead of 0.
"
At this point it is not clear what would be the consequences of this, and
whether this may lead to any problems, but this patch addresses the issue just
in case.
Cc: stable@vger.kernel.org
Tested-by: hujianyang <hujianyang@huawei.com>
Reported-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Diffstat (limited to 'fs/ubifs/log.c')
| -rw-r--r-- | fs/ubifs/log.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c index 9bd4aafd5c6f..c14628fbeee2 100644 --- a/fs/ubifs/log.c +++ b/fs/ubifs/log.c @@ -106,10 +106,14 @@ static inline long long empty_log_bytes(const struct ubifs_info *c) h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs; t = (long long)c->ltail_lnum * c->leb_size; - if (h >= t) + if (h > t) return c->log_bytes - h + t; - else + else if (h != t) return t - h; + else if (c->lhead_lnum != c->ltail_lnum) + return 0; + else + return c->log_bytes; } /** |