Jeff Layton <jlayton@xxxxxxxxxx> writes:
> 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.
Ah, nice! I remember _long_ time ago I had seen that field and thought:
"I'll need to send out a patch to remove this thing!". But in the
meantime I completely forgot.
>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> fs/ceph/caps.c | 36 +++---------------------------
> fs/ceph/inode.c | 11 ++-------
> fs/ceph/snap.c | 59 ++++++++++++++++++++++++++++++++-----------------
> fs/ceph/super.h | 2 +-
> 4 files changed, 45 insertions(+), 63 deletions(-)
>
> diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
> index cb551c9e5867..cecd4f66a60d 100644
> --- a/fs/ceph/caps.c
> +++ b/fs/ceph/caps.c
> @@ -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);
> }
> @@ -3083,7 +3053,7 @@ 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)) {
> diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> index 84e4f112fc45..61ecf81ed875 100644
> --- a/fs/ceph/inode.c
> +++ b/fs/ceph/inode.c
> @@ -582,16 +582,9 @@ 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;
> diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
> index 4ac0606dcbd4..9dbc92cfda38 100644
> --- a/fs/ceph/snap.c
> +++ b/fs/ceph/snap.c
> @@ -846,6 +846,43 @@ 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);
Just a suggestion: this function could received the struct
ceph_inode_info instead of the inode. Other than that, LGTM. Nice
cleanup! Feel free to add my
Reviewed-by: Luis Henriques <lhenriques@xxxxxxx>
(The other 2 patches ("print more information when..." and "remove
redundant initializations...") also look good BTW.)
Cheers
--
Luis
> + 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.
> @@ -932,7 +969,6 @@ 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;
> @@ -957,27 +993,10 @@ 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;
>
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index d51d42a00f33..389b45ac291b 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -422,7 +422,6 @@ 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;
> @@ -933,6 +932,7 @@ 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);
> --
>
> 2.31.1
>
