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| author | Tejun Heo <tj@kernel.org> | 2009-04-15 22:10:23 +0900 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2009-04-22 08:35:09 +0200 |
| commit | 23c560a99d78bddf5c251bfa97bce19e4da4b3f3 (patch) | |
| tree | 5c86aecb937ec49effaaf7cca526baf36c9c3eaf /lib/scatterlist.c | |
| parent | 091069740304c979f957ceacec39c461d0192158 (diff) | |
| download | lwn-23c560a99d78bddf5c251bfa97bce19e4da4b3f3.tar.gz lwn-23c560a99d78bddf5c251bfa97bce19e4da4b3f3.zip | |
scatterlist: make sure sg_miter_next() doesn't return 0 sized mappings
Impact: fix not-so-critical but annoying bug
sg_miter_next() returns 0 sized mapping if there is an zero sized sg
entry in the list or at the end of each iteration. As the users
always check the ->length field, this bug shouldn't be critical other
than causing unnecessary iteration.
Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'lib/scatterlist.c')
| -rw-r--r-- | lib/scatterlist.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/lib/scatterlist.c b/lib/scatterlist.c index b7b449dafbe5..a295e404e908 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -347,9 +347,12 @@ bool sg_miter_next(struct sg_mapping_iter *miter) sg_miter_stop(miter); /* get to the next sg if necessary. __offset is adjusted by stop */ - if (miter->__offset == miter->__sg->length && --miter->__nents) { - miter->__sg = sg_next(miter->__sg); - miter->__offset = 0; + while (miter->__offset == miter->__sg->length) { + if (--miter->__nents) { + miter->__sg = sg_next(miter->__sg); + miter->__offset = 0; + } else + return false; } /* map the next page */ |