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authorYan, Zheng <zyan@redhat.com>2017-11-15 17:39:40 +0800
committerIlya Dryomov <idryomov@gmail.com>2019-05-07 19:22:36 +0200
commit570df4e9c23f861aa3f8f2954468c534a033bf1a (patch)
tree79fd293eeae6aa7d42ab60d38637abc78df72f7e /include/linux/ceph
parent0c44a8e0fc55f56a70f72e67d7cc5b9341dae7d1 (diff)
ceph: snapshot nfs re-export
To support snapshot nfs re-export, we need a way to lookup snapped inode by file handle. For directory inode, snapped metadata are always stored together with head inode. Client just need to pass vinodeno_t to MDS. For non-directory inode, there can be multiple version of snapped inodes and they can be stored in different dirfrags. Besides vinodeno_t, client also need to tell mds from which dirfrag it got the snapped inode. Another problem of supporting snapshot nfs re-export is that there can be multiple paths to access a snapped inode. For example: mkdir -p d1/d2/d3 mkdir d1/.snap/s1 Paths 'd1/.snap/s1/d2/d3', 'd1/d2/.snap/_s1_<inode number of d1>/d3' and 'd1/d2/d3/.snap/_s1_<inode number of d1>' are all reference to the same snapped inode. For a given snapped inode, There is no convenient way to get the first form and the second form paths. For simplicity, ceph_get_parent() return snapdir for snapped directory inode. Furthermore, client may access snapshot of deleted directory. For example: mkdir -p d1/d2 mkdir d1/.snap/s1 open d1/.snap/s1/d2 rm -rf d1/d2 <nfs server restart> The path constucted by ceph_get_parent() and ceph_get_name() is '<inode of d2>/.snap/_s1_<inode number of d1>'. Futher lookup parent of <inode of d2> will fail. To workaround this case, this patch uses d_obtain_root() to get dentry for snapdir of deleted directory. snapdir dentry has no DCACHE_DISCONNECTED flag set, reconnect_path() stops when it reaches snapdir dentry. Link: http://tracker.ceph.com/issues/22105 Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'include/linux/ceph')
-rw-r--r--include/linux/ceph/ceph_fs.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index 4903deb0777a..3ac0feaf2b5e 100644
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -436,6 +436,12 @@ union ceph_mds_request_args {
__le64 length; /* num bytes to lock from start */
__u8 wait; /* will caller wait for lock to become available? */
} __attribute__ ((packed)) filelock_change;
+ struct {
+ __le32 mask; /* CEPH_CAP_* */
+ __le64 snapid;
+ __le64 parent;
+ __le32 hash;
+ } __attribute__ ((packed)) lookupino;
} __attribute__ ((packed));
#define CEPH_MDS_FLAG_REPLAY 1 /* this is a replayed op */