There's a hard limit on how large a read we can do from the OSD, defined
as CEPH_MSG_MAX_DATA_LEN (currently, 64M). It's possible to create a
file that is backed by larger objects than that (and indeed, xfstest
ceph/001 does just that).
Ensure we clamp the final length of a read to the rsize, which defaults
to CEPH_MSG_MAX_DATA_LEN, but can be set lower.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/ceph/addr.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
I think this version is more correct. Again, I'll plan to roll this into
the earlier patch that adds the clamp_length op.
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 9939100f9f9d..c1570fada3d8 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -205,6 +205,7 @@ static void ceph_netfs_expand_readahead(struct netfs_read_request *rreq)
static bool ceph_netfs_clamp_length(struct netfs_read_subrequest *subreq)
{
struct inode *inode = subreq->rreq->mapping->host;
+ struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_inode_info *ci = ceph_inode(inode);
u64 objno, objoff;
u32 xlen;
@@ -212,7 +213,7 @@ static bool ceph_netfs_clamp_length(struct netfs_read_subrequest *subreq)
/* Truncate the extent at the end of the current block */
ceph_calc_file_object_mapping(&ci->i_layout, subreq->start, subreq->len,
&objno, &objoff, &xlen);
- subreq->len = xlen;
+ subreq->len = min(xlen, fsc->mount_options->rsize);
return true;
}
--
2.31.1
