Commit 0ba92e1c authored by Jeff Layton's avatar Jeff Layton Committed by Ilya Dryomov
Browse files

ceph: add ceph_change_snap_realm() helper 



Consolidate some fiddly code for changing an inode's snap_realm
into a new helper function, and change the callers to use it.

While we're in here, nothing uses the i_snap_realm_counter field, so
remove that from the inode.

Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Reviewed-by: default avatarLuis Henriques <lhenriques@suse.de>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent c80dc3ae

fs/ceph/caps.c

+3 −33
Original line number Diff line number Diff line
@@ -704,23 +704,7 @@ void ceph_add_cap(struct inode *inode, 
		struct ceph_snap_realm *realm = ceph_lookup_snap_realm(mdsc,

							       realmino);

		if (realm) {

			struct ceph_snap_realm *oldrealm = ci->i_snap_realm;

			if (oldrealm) {

				spin_lock(&oldrealm->inodes_with_caps_lock);

				list_del_init(&ci->i_snap_realm_item);

				spin_unlock(&oldrealm->inodes_with_caps_lock);

			}



			spin_lock(&realm->inodes_with_caps_lock);

			list_add(&ci->i_snap_realm_item,

				 &realm->inodes_with_caps);

			ci->i_snap_realm = realm;

			if (realm->ino == ci->i_vino.ino)

				realm->inode = inode;

			spin_unlock(&realm->inodes_with_caps_lock);



			if (oldrealm)

				ceph_put_snap_realm(mdsc, oldrealm);

			ceph_change_snap_realm(inode, realm);

		} else {

			pr_err("ceph_add_cap: couldn't find snap realm %llx\n",

			       realmino);
@@ -1112,20 +1096,6 @@ int ceph_is_any_caps(struct inode *inode) 
	return ret;

}



static void drop_inode_snap_realm(struct ceph_inode_info *ci)

{

	struct ceph_snap_realm *realm = ci->i_snap_realm;

	spin_lock(&realm->inodes_with_caps_lock);

	list_del_init(&ci->i_snap_realm_item);

	ci->i_snap_realm_counter++;

	ci->i_snap_realm = NULL;

	if (realm->ino == ci->i_vino.ino)

		realm->inode = NULL;

	spin_unlock(&realm->inodes_with_caps_lock);

	ceph_put_snap_realm(ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc,

			    realm);

}



/*

 * Remove a cap.  Take steps to deal with a racing iterate_session_caps.

 *
@@ -1201,7 +1171,7 @@ void __ceph_remove_cap(struct ceph_cap *cap, bool queue_release) 
		 * keep i_snap_realm.

		 */

		if (ci->i_wr_ref == 0 && ci->i_snap_realm)

			drop_inode_snap_realm(ci);

			ceph_change_snap_realm(&ci->vfs_inode, NULL);



		__cap_delay_cancel(mdsc, ci);

	}
@@ -3084,7 +3054,7 @@ static void __ceph_put_cap_refs(struct ceph_inode_info *ci, int had, 
			}

			/* see comment in __ceph_remove_cap() */

			if (!__ceph_is_any_real_caps(ci) && ci->i_snap_realm)

				drop_inode_snap_realm(ci);

				ceph_change_snap_realm(inode, NULL);

		}

	}

	if (check_flushsnaps && __ceph_have_pending_cap_snap(ci)) {

fs/ceph/inode.c

+2 −9
Original line number Diff line number Diff line
@@ -581,16 +581,9 @@ void ceph_evict_inode(struct inode *inode) 
	 */

	if (ci->i_snap_realm) {

		if (ceph_snap(inode) == CEPH_NOSNAP) {

			struct ceph_snap_realm *realm = ci->i_snap_realm;

			dout(" dropping residual ref to snap realm %p\n",

			     realm);

			spin_lock(&realm->inodes_with_caps_lock);

			list_del_init(&ci->i_snap_realm_item);

			ci->i_snap_realm = NULL;

			if (realm->ino == ci->i_vino.ino)

				realm->inode = NULL;

			spin_unlock(&realm->inodes_with_caps_lock);

			ceph_put_snap_realm(mdsc, realm);

			     ci->i_snap_realm);

			ceph_change_snap_realm(inode, NULL);

		} else {

			ceph_put_snapid_map(mdsc, ci->i_snapid_map);

			ci->i_snap_realm = NULL;

fs/ceph/snap.c

+39 −20
Original line number Diff line number Diff line
@@ -849,6 +849,43 @@ static void flush_snaps(struct ceph_mds_client *mdsc) 
	dout("flush_snaps done\n");

}



/**

 * ceph_change_snap_realm - change the snap_realm for an inode

 * @inode: inode to move to new snap realm

 * @realm: new realm to move inode into (may be NULL)

 *

 * Detach an inode from its old snaprealm (if any) and attach it to

 * the new snaprealm (if any). The old snap realm reference held by

 * the inode is put. If realm is non-NULL, then the caller's reference

 * to it is taken over by the inode.

 */

void ceph_change_snap_realm(struct inode *inode, struct ceph_snap_realm *realm)

{

	struct ceph_inode_info *ci = ceph_inode(inode);

	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;

	struct ceph_snap_realm *oldrealm = ci->i_snap_realm;



	lockdep_assert_held(&ci->i_ceph_lock);



	if (oldrealm) {

		spin_lock(&oldrealm->inodes_with_caps_lock);

		list_del_init(&ci->i_snap_realm_item);

		if (oldrealm->ino == ci->i_vino.ino)

			oldrealm->inode = NULL;

		spin_unlock(&oldrealm->inodes_with_caps_lock);

		ceph_put_snap_realm(mdsc, oldrealm);

	}



	ci->i_snap_realm = realm;



	if (realm) {

		spin_lock(&realm->inodes_with_caps_lock);

		list_add(&ci->i_snap_realm_item, &realm->inodes_with_caps);

		if (realm->ino == ci->i_vino.ino)

			realm->inode = inode;

		spin_unlock(&realm->inodes_with_caps_lock);

	}

}



/*

 * Handle a snap notification from the MDS.
@@ -935,7 +972,6 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc, 
			};

			struct inode *inode = ceph_find_inode(sb, vino);

			struct ceph_inode_info *ci;

			struct ceph_snap_realm *oldrealm;



			if (!inode)

				continue;
@@ -960,27 +996,10 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc, 
			}

			dout(" will move %p to split realm %llx %p\n",

			     inode, realm->ino, realm);

			/*

			 * Move the inode to the new realm

			 */

			oldrealm = ci->i_snap_realm;

			spin_lock(&oldrealm->inodes_with_caps_lock);

			list_del_init(&ci->i_snap_realm_item);

			spin_unlock(&oldrealm->inodes_with_caps_lock);



			spin_lock(&realm->inodes_with_caps_lock);

			list_add(&ci->i_snap_realm_item,

				 &realm->inodes_with_caps);

			ci->i_snap_realm = realm;

			if (realm->ino == ci->i_vino.ino)

                                realm->inode = inode;

			spin_unlock(&realm->inodes_with_caps_lock);



			spin_unlock(&ci->i_ceph_lock);



			ceph_get_snap_realm(mdsc, realm);

			ceph_put_snap_realm(mdsc, oldrealm);



			ceph_change_snap_realm(inode, realm);

			spin_unlock(&ci->i_ceph_lock);

			iput(inode);

			continue;

fs/ceph/super.h

+1 −1
Original line number Diff line number Diff line
@@ -418,7 +418,6 @@ struct ceph_inode_info { 
		struct ceph_snap_realm *i_snap_realm; /* snap realm (if caps) */

		struct ceph_snapid_map *i_snapid_map; /* snapid -> dev_t */

	};

	int i_snap_realm_counter; /* snap realm (if caps) */

	struct list_head i_snap_realm_item;

	struct list_head i_snap_flush_item;

	struct timespec64 i_btime;
@@ -929,6 +928,7 @@ extern void ceph_put_snap_realm(struct ceph_mds_client *mdsc, 
extern int ceph_update_snap_trace(struct ceph_mds_client *m,

				  void *p, void *e, bool deletion,

				  struct ceph_snap_realm **realm_ret);

void ceph_change_snap_realm(struct inode *inode, struct ceph_snap_realm *realm);

extern void ceph_handle_snap(struct ceph_mds_client *mdsc,

			     struct ceph_mds_session *session,

			     struct ceph_msg *msg);