diff options
| author | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2011-09-13 17:01:39 -0400 |
|---|---|---|
| committer | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2011-11-04 15:53:04 -0400 |
| commit | d0ba1e497bca83a3d353eb47c9658afc54d83228 (patch) | |
| tree | 67357b1a15493caf232448fc8f5c13bf73fbe215 /drivers/block/nvme.c | |
| parent | 6413214c5d424fd5aae6567848340f962ad2ce0f (diff) | |
NVMe: Correct sg list setup in nvme_map_user_pages
Our SG list was constructed to always fill the entire first page, even
if that was more than the length of the I/O. This is probably harmless,
but some IOMMUs might do something bad.
Correcting the first call to sg_set_page() made it look a lot closer to
the sg_set_page() in the loop, so fold the first call to sg_set_page()
into the loop.
Reported-by: Nisheeth Bhat <nisheeth.bhat@intel.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Diffstat (limited to 'drivers/block/nvme.c')
| -rw-r--r-- | drivers/block/nvme.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c index 0956e124152..5843409cac6 100644 --- a/drivers/block/nvme.c +++ b/drivers/block/nvme.c @@ -996,11 +996,11 @@ static int nvme_map_user_pages(struct nvme_dev *dev, int write, sg = kcalloc(count, sizeof(*sg), GFP_KERNEL); sg_init_table(sg, count); - sg_set_page(&sg[0], pages[0], PAGE_SIZE - offset, offset); - length -= (PAGE_SIZE - offset); - for (i = 1; i < count; i++) { - sg_set_page(&sg[i], pages[i], min_t(int, length, PAGE_SIZE), 0); - length -= PAGE_SIZE; + for (i = 0; i < count; i++) { + sg_set_page(&sg[i], pages[i], + min_t(int, length, PAGE_SIZE - offset), offset); + length -= (PAGE_SIZE - offset); + offset = 0; } err = -ENOMEM; |