Re: [PATCH v4 1/1] DM: inplace compressed DM target (fwd)

From: Julia Lawall
Date: Tue Feb 14 2017 - 01:09:13 EST


On line 1759, since ret is unsigned it will not be less than 0.

julia

---------- Forwarded message ----------
Date: Tue, 14 Feb 2017 09:00:39 +0800
From: kbuild test robot <fengguang.wu@xxxxxxxxx>
To: kbuild@xxxxxx
Cc: Julia Lawall <julia.lawall@xxxxxxx>
Subject: Re: [PATCH v4 1/1] DM: inplace compressed DM target

CC: kbuild-all@xxxxxx
In-Reply-To: <1487018545-5061-2-git-send-email-linuxram@xxxxxxxxxx>

Hi Ram,

[auto build test WARNING on dm/for-next]
[also build test WARNING on v4.10-rc8 next-20170213]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Ram-Pai/DM-inplace-compressed-DM-target/20170214-055727
base: https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git for-next
:::::: branch date: 3 hours ago
:::::: commit date: 3 hours ago

>> drivers/md/dm-inplace-compress.c:1759:5-8: WARNING: Unsigned expression compared with zero: ret < 0

git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout e7924efaaba5efdcd28f32efbb949ed1153c932c
vim +1759 drivers/md/dm-inplace-compress.c

e7924efa Ram Pai 2017-02-13 1743 * @io : io range
e7924efa Ram Pai 2017-02-13 1744 * @sector_start : the sector on backing storage to which the
e7924efa Ram Pai 2017-02-13 1745 * compressed data needs to be written.
e7924efa Ram Pai 2017-02-13 1746 * @meta_start: the page index of the bits corresponding to
e7924efa Ram Pai 2017-02-13 1747 * @meta_end : start and end blocks.
e7924efa Ram Pai 2017-02-13 1748 */
e7924efa Ram Pai 2017-02-13 1749 static int dm_icomp_compress_write(struct dm_icomp_io_range *io,
e7924efa Ram Pai 2017-02-13 1750 sector_t sector_start, u64 *meta_start, u64 *meta_end)
e7924efa Ram Pai 2017-02-13 1751 {
e7924efa Ram Pai 2017-02-13 1752 struct dm_icomp_req *req = io->req;
e7924efa Ram Pai 2017-02-13 1753 sector_t count = DMCP_BYTES_TO_SECTOR(io->decomp_len);
e7924efa Ram Pai 2017-02-13 1754 unsigned int comp_len, ret;
e7924efa Ram Pai 2017-02-13 1755 u64 page_index;
e7924efa Ram Pai 2017-02-13 1756
e7924efa Ram Pai 2017-02-13 1757 /* comp_data must be able to accommadate a larger compress buffer */
e7924efa Ram Pai 2017-02-13 1758 ret = dm_icomp_io_range_compress(req->info, io, &comp_len);
e7924efa Ram Pai 2017-02-13 @1759 if (ret < 0) {
e7924efa Ram Pai 2017-02-13 1760 req->result = -EIO;
e7924efa Ram Pai 2017-02-13 1761 return -EIO;
e7924efa Ram Pai 2017-02-13 1762 }
e7924efa Ram Pai 2017-02-13 1763 WARN_ON(comp_len > io->comp_len);
e7924efa Ram Pai 2017-02-13 1764
e7924efa Ram Pai 2017-02-13 1765 dm_icomp_get_req(req);
e7924efa Ram Pai 2017-02-13 1766
e7924efa Ram Pai 2017-02-13 1767 io->io_req.bi_op = REQ_OP_WRITE;

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