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authorIlya Dryomov <ilya.dryomov@inktank.com>2014-08-08 12:43:39 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-09-17 09:04:01 -0700
commita64897279757e1e98b6b1d98e0bba561b0f88331 (patch)
tree7c61fa53958af014b0d7a8ba94ce4ab091fcc2b2
parentb08633de6ba926a3412292b3239bf41a3f00912b (diff)
downloadlwn-a64897279757e1e98b6b1d98e0bba561b0f88331.tar.gz
lwn-a64897279757e1e98b6b1d98e0bba561b0f88331.zip
libceph: set last_piece in ceph_msg_data_pages_cursor_init() correctly
commit 5f740d7e1531099b888410e6bab13f68da9b1a4d upstream. Determining ->last_piece based on the value of ->page_offset + length is incorrect because length here is the length of the entire message. ->last_piece set to false even if page array data item length is <= PAGE_SIZE, which results in invalid length passed to ceph_tcp_{send,recv}page() and causes various asserts to fire. # cat pages-cursor-init.sh #!/bin/bash rbd create --size 10 --image-format 2 foo FOO_DEV=$(rbd map foo) dd if=/dev/urandom of=$FOO_DEV bs=1M &>/dev/null rbd snap create foo@snap rbd snap protect foo@snap rbd clone foo@snap bar # rbd_resize calls librbd rbd_resize(), size is in bytes ./rbd_resize bar $(((4 << 20) + 512)) rbd resize --size 10 bar BAR_DEV=$(rbd map bar) # trigger a 512-byte copyup -- 512-byte page array data item dd if=/dev/urandom of=$BAR_DEV bs=1M count=1 seek=5 The problem exists only in ceph_msg_data_pages_cursor_init(), ceph_msg_data_pages_advance() does the right thing. The size_t cast is unnecessary. Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com> Reviewed-by: Sage Weil <sage@redhat.com> Reviewed-by: Alex Elder <elder@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/ceph/messenger.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index b9d7df175700..6ff7d9dc240f 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -904,7 +904,7 @@ static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data_cursor *cursor,
BUG_ON(page_count > (int)USHRT_MAX);
cursor->page_count = (unsigned short)page_count;
BUG_ON(length > SIZE_MAX - cursor->page_offset);
- cursor->last_piece = (size_t)cursor->page_offset + length <= PAGE_SIZE;
+ cursor->last_piece = cursor->page_offset + cursor->resid <= PAGE_SIZE;
}
static struct page *