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authorArtem Bityutskiy <artem.bityutskiy@linux.intel.com>2014-07-16 15:22:29 +0300
committerJiri Slaby <jslaby@suse.cz>2014-11-13 19:02:11 +0100
commit4f111bbc16e4d6c657c8f53f50d7a9cfa7f37e4f (patch)
tree4059c460a6038282897f710cd8cf9473bf1948b8 /fs/ubifs
parentc52a27957eb0e9f84c7d43767d0b41c6415ee2c8 (diff)
UBIFS: fix free log space calculation
commit ba29e721eb2df6df8f33c1f248388bb037a47914 upstream. 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. Tested-by: hujianyang <hujianyang@huawei.com> Reported-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'fs/ubifs')
-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 be67120fb919..06649d21b056 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;
}
/**