From acfdf5c383b38f7f4dddae41b97c97f1ae058f49 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Mon, 31 Jan 2011 19:20:39 -0500 Subject: nfsd4: acquire only one lease per file Instead of acquiring one lease each time another client opens a file, nfsd can acquire just one lease to represent all of them, and reference count it to determine when to release it. This fixes a regression introduced by c45821d263a8a5109d69a9e8942b8d65bcd5f31a "locks: eliminate fl_mylease callback": after that patch, only the struct file * is used to determine who owns a given lease. But since we recently converted the server to share a single struct file per open, if we acquire multiple leases on the same file from nfsd, it then becomes impossible on unlocking a lease to determine which of those leases (all of whom share the same struct file *) we meant to remove. Thanks to Takashi Iwai for catching a bug in a previous version of this patch. Tested-by: Takashi Iwai Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 95 +++++++++++++++++++++++++++++++---------------------- fs/nfsd/state.h | 5 +-- 2 files changed, 58 insertions(+), 42 deletions(-) (limited to 'fs') diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 8b6cd3cf4835..54b60bfceb8d 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -230,9 +230,6 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_f dp->dl_client = clp; get_nfs4_file(fp); dp->dl_file = fp; - dp->dl_vfs_file = find_readable_file(fp); - get_file(dp->dl_vfs_file); - dp->dl_flock = NULL; dp->dl_type = type; dp->dl_stateid.si_boot = boot_time; dp->dl_stateid.si_stateownerid = current_delegid++; @@ -241,8 +238,6 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_f fh_copy_shallow(&dp->dl_fh, ¤t_fh->fh_handle); dp->dl_time = 0; atomic_set(&dp->dl_count, 1); - list_add(&dp->dl_perfile, &fp->fi_delegations); - list_add(&dp->dl_perclnt, &clp->cl_delegations); INIT_WORK(&dp->dl_recall.cb_work, nfsd4_do_callback_rpc); return dp; } @@ -253,24 +248,18 @@ nfs4_put_delegation(struct nfs4_delegation *dp) if (atomic_dec_and_test(&dp->dl_count)) { dprintk("NFSD: freeing dp %p\n",dp); put_nfs4_file(dp->dl_file); - fput(dp->dl_vfs_file); kmem_cache_free(deleg_slab, dp); num_delegations--; } } -/* Remove the associated file_lock first, then remove the delegation. - * lease_modify() is called to remove the FS_LEASE file_lock from - * the i_flock list, eventually calling nfsd's lock_manager - * fl_release_callback. - */ -static void -nfs4_close_delegation(struct nfs4_delegation *dp) +static void nfs4_put_deleg_lease(struct nfs4_file *fp) { - dprintk("NFSD: close_delegation dp %p\n",dp); - /* XXX: do we even need this check?: */ - if (dp->dl_flock) - vfs_setlease(dp->dl_vfs_file, F_UNLCK, &dp->dl_flock); + if (atomic_dec_and_test(&fp->fi_delegees)) { + vfs_setlease(fp->fi_deleg_file, F_UNLCK, &fp->fi_lease); + fp->fi_lease = NULL; + fp->fi_deleg_file = NULL; + } } /* Called under the state lock. */ @@ -282,7 +271,7 @@ unhash_delegation(struct nfs4_delegation *dp) list_del_init(&dp->dl_perfile); list_del_init(&dp->dl_recall_lru); spin_unlock(&recall_lock); - nfs4_close_delegation(dp); + nfs4_put_deleg_lease(dp->dl_file); nfs4_put_delegation(dp); } @@ -2076,6 +2065,7 @@ alloc_init_file(struct inode *ino) fp->fi_inode = igrab(ino); fp->fi_id = current_fileid++; fp->fi_had_conflict = false; + fp->fi_lease = NULL; memset(fp->fi_fds, 0, sizeof(fp->fi_fds)); memset(fp->fi_access, 0, sizeof(fp->fi_access)); spin_lock(&recall_lock); @@ -2344,26 +2334,26 @@ static void nfsd_break_one_deleg(struct nfs4_delegation *dp) nfsd4_cb_recall(dp); } -/* - * Called from break_lease() with lock_flocks() held. - * Note: we assume break_lease will only call this *once* for any given - * lease. - */ +/* Called from break_lease() with lock_flocks() held. */ static void nfsd_break_deleg_cb(struct file_lock *fl) { - struct nfs4_delegation *dp = (struct nfs4_delegation *)fl->fl_owner; + struct nfs4_file *fp = (struct nfs4_file *)fl->fl_owner; + struct nfs4_delegation *dp; - BUG_ON(!dp); + BUG_ON(!fp); + /* We assume break_lease is only called once per lease: */ + BUG_ON(fp->fi_had_conflict); /* * We don't want the locks code to timeout the lease for us; - * we'll remove it ourself if the delegation isn't returned + * we'll remove it ourself if a delegation isn't returned * in time: */ fl->fl_break_time = 0; spin_lock(&recall_lock); - dp->dl_file->fi_had_conflict = true; - nfsd_break_one_deleg(dp); + fp->fi_had_conflict = true; + list_for_each_entry(dp, &fp->fi_delegations, dl_perfile) + nfsd_break_one_deleg(dp); spin_unlock(&recall_lock); } @@ -2455,13 +2445,15 @@ nfs4_check_delegmode(struct nfs4_delegation *dp, int flags) static struct nfs4_delegation * find_delegation_file(struct nfs4_file *fp, stateid_t *stid) { - struct nfs4_delegation *dp; + struct nfs4_delegation *dp = NULL; + spin_lock(&recall_lock); list_for_each_entry(dp, &fp->fi_delegations, dl_perfile) { if (dp->dl_stateid.si_stateownerid == stid->si_stateownerid) - return dp; + break; } - return NULL; + spin_unlock(&recall_lock); + return dp; } int share_access_to_flags(u32 share_access) @@ -2649,28 +2641,51 @@ static struct file_lock *nfs4_alloc_init_lease(struct nfs4_delegation *dp, int f fl->fl_flags = FL_LEASE; fl->fl_type = flag == NFS4_OPEN_DELEGATE_READ? F_RDLCK: F_WRLCK; fl->fl_end = OFFSET_MAX; - fl->fl_owner = (fl_owner_t)dp; - fl->fl_file = dp->dl_vfs_file; - BUG_ON(!fl->fl_file); + fl->fl_owner = (fl_owner_t)(dp->dl_file); fl->fl_pid = current->tgid; - dp->dl_flock = fl; return fl; } static int nfs4_setlease(struct nfs4_delegation *dp, int flag) { + struct nfs4_file *fp = dp->dl_file; struct file_lock *fl; int status; fl = nfs4_alloc_init_lease(dp, flag); if (!fl) return -ENOMEM; - status = vfs_setlease(dp->dl_vfs_file, fl->fl_type, &fl); + fl->fl_file = find_readable_file(fp); + list_add(&dp->dl_perclnt, &dp->dl_client->cl_delegations); + status = vfs_setlease(fl->fl_file, fl->fl_type, &fl); if (status) { - dp->dl_flock = NULL; + list_del_init(&dp->dl_perclnt); locks_free_lock(fl); return -ENOMEM; } + fp->fi_lease = fl; + fp->fi_deleg_file = fl->fl_file; + get_file(fp->fi_deleg_file); + atomic_set(&fp->fi_delegees, 1); + list_add(&dp->dl_perfile, &fp->fi_delegations); + return 0; +} + +static int nfs4_set_delegation(struct nfs4_delegation *dp, int flag) +{ + struct nfs4_file *fp = dp->dl_file; + + if (!fp->fi_lease) + return nfs4_setlease(dp, flag); + spin_lock(&recall_lock); + if (fp->fi_had_conflict) { + spin_unlock(&recall_lock); + return -EAGAIN; + } + atomic_inc(&fp->fi_delegees); + list_add(&dp->dl_perfile, &fp->fi_delegations); + spin_unlock(&recall_lock); + list_add(&dp->dl_perclnt, &dp->dl_client->cl_delegations); return 0; } @@ -2715,7 +2730,7 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_sta dp = alloc_init_deleg(sop->so_client, stp, fh, flag); if (dp == NULL) goto out_no_deleg; - status = nfs4_setlease(dp, flag); + status = nfs4_set_delegation(dp, flag); if (status) goto out_free; @@ -2731,7 +2746,7 @@ out: open->op_delegate_type = flag; return; out_free: - unhash_delegation(dp); + nfs4_put_delegation(dp); out_no_deleg: flag = NFS4_OPEN_DELEGATE_NONE; goto out; @@ -3139,7 +3154,7 @@ nfs4_preprocess_stateid_op(struct nfsd4_compound_state *cstate, goto out; renew_client(dp->dl_client); if (filpp) { - *filpp = find_readable_file(dp->dl_file); + *filpp = dp->dl_file->fi_deleg_file; BUG_ON(!*filpp); } } else { /* open or lock stateid */ diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 3074656ba7bf..2d31224b07bf 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -83,8 +83,6 @@ struct nfs4_delegation { atomic_t dl_count; /* ref count */ struct nfs4_client *dl_client; struct nfs4_file *dl_file; - struct file *dl_vfs_file; - struct file_lock *dl_flock; u32 dl_type; time_t dl_time; /* For recall: */ @@ -379,6 +377,9 @@ struct nfs4_file { */ atomic_t fi_readers; atomic_t fi_writers; + struct file *fi_deleg_file; + struct file_lock *fi_lease; + atomic_t fi_delegees; struct inode *fi_inode; u32 fi_id; /* used with stateowner->so_id * for stateid_hashtbl hash */ -- cgit