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authorArtem Bityutskiy <artem.bityutskiy@linux.intel.com>2014-07-16 15:22:29 +0300
committerArtem Bityutskiy <artem.bityutskiy@linux.intel.com>2014-09-08 15:55:28 +0300
commitba29e721eb2df6df8f33c1f248388bb037a47914 (patch)
treee10db004cdbc4027d0046838ec9bee534a09f2c1 /fs/ubifs/log.c
parent052c28073ff26f771d44ef33952a41d18dadd255 (diff)
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.c8
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;
}
/**