Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorDavid Howells <dhowells@redhat.com>2017-11-02 15:27:51 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-12-14 09:53:14 +0100
commit49e186e3278d0d800021b59286dc97d748593fd6 (patch)
treef5ae85c3cd3412b59a38e9c6f72e25d01a2bc785
parentd702be100eaf043b97687c050565c154a48d763d (diff)
afs: Fix total-length calculation for multiple-page send
[ Upstream commit 1199db603511d7463d9d3840f96f61967affc766 ] Fix the total-length calculation in afs_make_call() when the operation being dispatched has data from a series of pages attached. Despite the patched code looking like that it should reduce mathematically to the current code, it doesn't because the 32-bit unsigned arithmetic being used to calculate the page-offset-difference doesn't correctly extend to a 64-bit value when the result is effectively negative. Without this, some FS.StoreData operations that span multiple pages fail, reporting too little or too much data. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/afs/rxrpc.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 0bf191f0dbaf..9f715c3edcf9 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -377,8 +377,17 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
*/
tx_total_len = call->request_size;
if (call->send_pages) {
- tx_total_len += call->last_to - call->first_offset;
- tx_total_len += (call->last - call->first) * PAGE_SIZE;
+ if (call->last == call->first) {
+ tx_total_len += call->last_to - call->first_offset;
+ } else {
+ /* It looks mathematically like you should be able to
+ * combine the following lines with the ones above, but
+ * unsigned arithmetic is fun when it wraps...
+ */
+ tx_total_len += PAGE_SIZE - call->first_offset;
+ tx_total_len += call->last_to;
+ tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
+ }
}
/* create a call */