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| author | Josh Durgin <josh.durgin@inktank.com> | 2014-04-04 21:06:32 +0200 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@redhat.com> | 2014-10-14 19:03:32 +0200 |
| commit | 3c5df89367761d09d76454a2c4301a73bf2d46ce (patch) | |
| tree | 2e03d9e6e1d75a8558610fcee226f6e1f9fe6fc4 /drivers/block/rbd.c | |
| parent | rbd: initial discard bits from Guangliang Zhao (diff) | |
| download | linux-3c5df89367761d09d76454a2c4301a73bf2d46ce.tar.xz linux-3c5df89367761d09d76454a2c4301a73bf2d46ce.zip | |
rbd: read image size for discard check safely
In rbd_img_request_fill() the image size is only checked to determine
whether we can truncate an object instead of zeroing it for discard
requests. Take rbd_dev->header_rwsem while reading the image size, and
move this read into the discard check, so that non-discard ops don't
need to take the semaphore in this function.
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Diffstat (limited to 'drivers/block/rbd.c')
| -rw-r--r-- | drivers/block/rbd.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index e2f7a708e20d..31ace3dd33e4 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -2332,7 +2332,6 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, (int)type, data_desc); img_offset = img_request->offset; - img_end = rbd_dev->header.image_size; resid = img_request->length; rbd_assert(resid > 0); @@ -2397,13 +2396,20 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, if (!offset && (length == object_size) && (!img_request_layered_test(img_request) || (rbd_dev->parent_overlap <= - obj_request->img_offset))) + obj_request->img_offset))) { opcode = CEPH_OSD_OP_DELETE; - else if ((offset + length == object_size) || - (obj_request->img_offset + length == img_end)) + } else if ((offset + length == object_size)) { opcode = CEPH_OSD_OP_TRUNCATE; - else - opcode = CEPH_OSD_OP_ZERO; + } else { + down_read(&rbd_dev->header_rwsem); + img_end = rbd_dev->header.image_size; + up_read(&rbd_dev->header_rwsem); + + if (obj_request->img_offset + length == img_end) + opcode = CEPH_OSD_OP_TRUNCATE; + else + opcode = CEPH_OSD_OP_ZERO; + } } else if (img_request_write_test(img_request)) { op_type = OBJ_OP_WRITE; opcode = CEPH_OSD_OP_WRITE; |