diff options
| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-04-18 11:34:55 -0400 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-04-18 11:34:55 -0400 |
| commit | e93504933ee6982bdc005fa5c24e1ea330faaf8b (patch) | |
| tree | 4e775c9ab335e82cc5ffdbf54d49d8cb91f12adf /drivers | |
| parent | 9f3aedf573dd034d59e7eb6c4ee97648d5be8fc6 (diff) | |
xen/blkback: Move the check for misaligned I/O once more.
The commit 976222e05ea5a9959ccf880d7a24efbf79b3c6cf
xen/blkback: Move the check for misaligned I/O higher.
moved it a bit to high. The preq->vbdev was not set, so the
check for misaligned I/O would cause a NULL pointer derefence.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/xen/blkback/blkback.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/xen/blkback/blkback.c b/drivers/xen/blkback/blkback.c index c645c83f900b..a0d3227955c9 100644 --- a/drivers/xen/blkback/blkback.c +++ b/drivers/xen/blkback/blkback.c @@ -514,6 +514,7 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, pending_req->operation = req->operation; pending_req->status = BLKIF_RSP_OKAY; pending_req->nr_pages = nseg; + for (i = 0; i < nseg; i++) { seg[i].nsec = req->u.rw.seg[i].last_sect - req->u.rw.seg[i].first_sect + 1; @@ -522,12 +523,6 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, goto fail_response; preq.nr_sects += seg[i].nsec; - if (((int)preq.sector_number|(int)seg[i].nsec) & - ((bdev_logical_block_size(preq.bdev) >> 9) - 1)) { - DPRINTK("Misaligned I/O request from domain %d", - blkif->domid); - goto fail_response; - } } if (vbd_translate(&preq, blkif, operation) != 0) { @@ -537,6 +532,16 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, preq.sector_number + preq.nr_sects, preq.dev); goto fail_response; } + /* This check _MUST_ be done after vbd_translate as the preq.bdev + * is set there. */ + for (i = 0; i < nseg; i++) { + if (((int)preq.sector_number|(int)seg[i].nsec) & + ((bdev_logical_block_size(preq.bdev) >> 9) - 1)) { + DPRINTK("Misaligned I/O request from domain %d", + blkif->domid); + goto fail_response; + } + } /* If we have failed at this point, we need to undo the M2P override, * set gnttab_set_unmap_op on all of the grant references and perform * the hypercall to unmap the grants - that is all done in |