diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index c1cc993225e3..f64576e72b79 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -288,6 +288,9 @@ static int cmpu64_rev(const void *a, const void *b) return 0; } + +static struct ceph_snap_context *empty_snapc; + /* * build the snap context for a given realm. */ @@ -328,6 +331,12 @@ static int build_snap_context(struct ceph_snap_realm *realm) return 0; } + if (num == 0 && realm->seq == empty_snapc->seq) { + ceph_get_snap_context(empty_snapc); + snapc = empty_snapc; + goto done; + } + /* alloc new snap context */ err = -ENOMEM; if (num > (SIZE_MAX - sizeof(*snapc)) / sizeof(u64)) @@ -365,6 +374,7 @@ static int build_snap_context(struct ceph_snap_realm *realm) realm->ino, realm, snapc, snapc->seq, (unsigned int) snapc->num_snaps); +done: ceph_put_snap_context(realm->cached_context); realm->cached_context = snapc; return 0; @@ -465,6 +475,9 @@ void ceph_queue_cap_snap(struct ceph_inode_info *ci) cap_snap. lucky us. */ dout("queue_cap_snap %p already pending\n", inode); kfree(capsnap); + } else if (ci->i_snap_realm->cached_context == empty_snapc) { + dout("queue_cap_snap %p empty snapc\n", inode); + kfree(capsnap); } else if (dirty & (CEPH_CAP_AUTH_EXCL|CEPH_CAP_XATTR_EXCL| CEPH_CAP_FILE_EXCL|CEPH_CAP_FILE_WR)) { struct ceph_snap_context *snapc = ci->i_head_snapc; @@ -925,5 +938,16 @@ out: return; } +int __init ceph_snap_init(void) +{ + empty_snapc = ceph_create_snap_context(0, GFP_NOFS); + if (!empty_snapc) + return -ENOMEM; + empty_snapc->seq = 1; + return 0; +} - +void ceph_snap_exit(void) +{ + ceph_put_snap_context(empty_snapc); +} diff --git a/fs/ceph/super.c b/fs/ceph/super.c index f6e12377335c..3b5c1e3335db 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -1028,15 +1028,20 @@ static int __init init_ceph(void) ceph_flock_init(); ceph_xattr_init(); + ret = ceph_snap_init(); + if (ret) + goto out_xattr; ret = register_filesystem(&ceph_fs_type); if (ret) - goto out_icache; + goto out_snap; pr_info("loaded (mds proto %d)\n", CEPH_MDSC_PROTOCOL); return 0; -out_icache: +out_snap: + ceph_snap_exit(); +out_xattr: ceph_xattr_exit(); destroy_caches(); out: @@ -1047,6 +1052,7 @@ static void __exit exit_ceph(void) { dout("exit_ceph\n"); unregister_filesystem(&ceph_fs_type); + ceph_snap_exit(); ceph_xattr_exit(); destroy_caches(); } diff --git a/fs/ceph/super.h b/fs/ceph/super.h index aca22879b41f..fc1c8255dead 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -699,6 +699,8 @@ extern void ceph_queue_cap_snap(struct ceph_inode_info *ci); extern int __ceph_finish_cap_snap(struct ceph_inode_info *ci, struct ceph_cap_snap *capsnap); extern void ceph_cleanup_empty_realms(struct ceph_mds_client *mdsc); +extern int ceph_snap_init(void); +extern void ceph_snap_exit(void); /* * a cap_snap is "pending" if it is still awaiting an in-progress