[ 13/24] libceph: check for invalid mapping

Greg Kroah-Hartman
2012-11-02T17:07:57Z

From: Sage Weil <sage@inktank.com>

commit d63b77f4c552cc3a20506871046ab0fcbc332609 upstream.

If we encounter an invalid (e.g., zeroed) mapping, return an error
and avoid a divide by zero.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/linux/ceph/osd_client.h | 2 +-
include/linux/ceph/osdmap.h | 6 +++---
net/ceph/osd_client.c | 32 ++++++++++++++++++++------------
net/ceph/osdmap.c | 18 ++++++++++++++++--
4 files changed, 40 insertions(+), 18 deletions(-)

--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -207,7 +207,7 @@ extern void ceph_osdc_handle_reply(struc
extern void ceph_osdc_handle_map(struct ceph_osd_client *osdc,
struct ceph_msg *msg);

-extern void ceph_calc_raw_layout(struct ceph_osd_client *osdc,
+extern int ceph_calc_raw_layout(struct ceph_osd_client *osdc,
struct ceph_file_layout *layout,
u64 snapid,
u64 off, u64 *plen, u64 *bno,
--- a/include/linux/ceph/osdmap.h
+++ b/include/linux/ceph/osdmap.h
@@ -109,9 +109,9 @@ extern struct ceph_osdmap *osdmap_apply_
extern void ceph_osdmap_destroy(struct ceph_osdmap *map);

/* calculate mapping of a file extent to an object */
-extern void ceph_calc_file_object_mapping(struct ceph_file_layout *layout,
- u64 off, u64 *plen,
- u64 *bno, u64 *oxoff, u64 *oxlen);
+extern int ceph_calc_file_object_mapping(struct ceph_file_layout *layout,
+ u64 off, u64 *plen,
+ u64 *bno, u64 *oxoff, u64 *oxlen);

/* calculate mapping of object to a placement group */
extern int ceph_calc_object_layout(struct ceph_object_layout *ol,
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -52,7 +52,7 @@ static int op_has_extent(int op)
op == CEPH_OSD_OP_WRITE);
}

-void ceph_calc_raw_layout(struct ceph_osd_client *osdc,
+int ceph_calc_raw_layout(struct ceph_osd_client *osdc,
struct ceph_file_layout *layout,
u64 snapid,
u64 off, u64 *plen, u64 *bno,
@@ -62,12 +62,15 @@ void ceph_calc_raw_layout(struct ceph_os
struct ceph_osd_request_head *reqhead = req->r_request->front.iov_base;
u64 orig_len = *plen;
u64 objoff, objlen; /* extent in object */
+ int r;

reqhead->snapid = cpu_to_le64(snapid);

/* object extent? */
- ceph_calc_file_object_mapping(layout, off, plen, bno,
- &objoff, &objlen);
+ r = ceph_calc_file_object_mapping(layout, off, plen, bno,
+ &objoff, &objlen);
+ if (r < 0)
+ return r;
if (*plen < orig_len)
dout(" skipping last %llu, final file extent %llu~%llu\n",
orig_len - *plen, off, *plen);
@@ -83,7 +86,7 @@ void ceph_calc_raw_layout(struct ceph_os

dout("calc_layout bno=%llx %llu~%llu (%d pages)\n",
*bno, objoff, objlen, req->r_num_pages);
-
+ return 0;
}
EXPORT_SYMBOL(ceph_calc_raw_layout);

@@ -112,20 +115,25 @@ EXPORT_SYMBOL(ceph_calc_raw_layout);
*
* fill osd op in request message.
*/
-static void calc_layout(struct ceph_osd_client *osdc,
- struct ceph_vino vino,
- struct ceph_file_layout *layout,
- u64 off, u64 *plen,
- struct ceph_osd_request *req,
- struct ceph_osd_req_op *op)
+static int calc_layout(struct ceph_osd_client *osdc,
+ struct ceph_vino vino,
+ struct ceph_file_layout *layout,
+ u64 off, u64 *plen,
+ struct ceph_osd_request *req,
+ struct ceph_osd_req_op *op)
{
u64 bno;
+ int r;

- ceph_calc_raw_layout(osdc, layout, vino.snap, off,
- plen, &bno, req, op);
+ r = ceph_calc_raw_layout(osdc, layout, vino.snap, off,
+ plen, &bno, req, op);
+ if (r < 0)
+ return r;

snprintf(req->r_oid, sizeof(req->r_oid), "%llx.%08llx", vino.ino, bno);
req->r_oid_len = strlen(req->r_oid);
+
+ return r;
}

/*
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -984,7 +984,7 @@ bad:
* for now, we write only a single su, until we can
* pass a stride back to the caller.
*/
-void ceph_calc_file_object_mapping(struct ceph_file_layout *layout,
+int ceph_calc_file_object_mapping(struct ceph_file_layout *layout,
u64 off, u64 *plen,
u64 *ono,
u64 *oxoff, u64 *oxlen)
@@ -998,11 +998,17 @@ void ceph_calc_file_object_mapping(struc

dout("mapping %llu~%llu osize %u fl_su %u\n", off, *plen,
osize, su);
+ if (su == 0 || sc == 0)
+ goto invalid;
su_per_object = osize / su;
+ if (su_per_object == 0)
+ goto invalid;
dout("osize %u / su %u = su_per_object %u\n", osize, su,
su_per_object);

- BUG_ON((su & ~PAGE_MASK) != 0);
+ if ((su & ~PAGE_MASK) != 0)
+ goto invalid;
+
/* bl = *off / su; */
t = off;
do_div(t, su);
@@ -1030,6 +1036,14 @@ void ceph_calc_file_object_mapping(struc
*plen = *oxlen;

dout(" obj extent %llu~%llu\n", *oxoff, *oxlen);
+ return 0;
+
+invalid:
+ dout(" invalid layout\n");
+ *ono = 0;
+ *oxoff = 0;
+ *oxlen = 0;
+ return -EINVAL;
}
EXPORT_SYMBOL(ceph_calc_file_object_mapping);