From fbcd4abcb3841f85578985c09c6df85aa41b0ae8 Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Wed, 1 Apr 2009 09:22:15 -0400 Subject: [PATCH] nfs41: setup_sequence method Allocate a slot in the session slot table and set the sequence op arguments. Called at the rpc prepare stage. Add a status to nfs41_sequence_res, initialize it to one so that we catch rpc level failures which do not go through decode_sequence which sets the new status field. Note that upon an rpc level failure, we don't know if the server processed the sequence operation or not. Proceed as if the server did process the sequence operation. Signed-off-by: Rahul Iyer [nfs41: sequence args use slotid] [nfs41: find slot return slotid] Signed-off-by: Andy Adamson Signed-off-by: Benny Halevy [nfs41: remove SEQ4_STATUS_USE_TK_STATUS] As per 11-14-08 review [move extern declaration from nfs41: sequence setup/done support] [removed sa_session definition, changed sa_cache_this into a u8 to reduce footprint] Signed-off-by: Andy Adamson Signed-off-by: Benny Halevy [nfs41: rpc_sleep_on slot_tbl_waitq must be called under slot_tbl_lock] Otherwise there's a race (we've hit) with nfs4_free_slot where nfs41_setup_sequence sees a full slot table, unlocks slot_tbl_lock, nfs4_free_slots happen concurrently and call rpc_wake_up_next where there's nobody to wake up yet, context goes back to nfs41_setup_sequence which goes to sleep when the slot table is actually empty now and there's no-one to wake it up anymore. Signed-off-by: Benny Halevy Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 10 ++++++++++ fs/nfs/nfs4proc.c | 34 ++++++++++++++++++++++++++++++++-- include/linux/nfs_xdr.h | 4 ++++ 3 files changed, 46 insertions(+), 2 deletions(-) diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index acac6f8c3d39..eccf4e93e7d7 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -203,8 +203,18 @@ extern int nfs4_proc_fs_locations(struct inode *dir, const struct qstr *name, extern struct nfs4_state_recovery_ops nfs4_reboot_recovery_ops; extern struct nfs4_state_recovery_ops nfs4_nograce_recovery_ops; #if defined(CONFIG_NFS_V4_1) +extern int nfs4_setup_sequence(struct nfs_client *clp, + struct nfs4_sequence_args *args, struct nfs4_sequence_res *res, + int cache_reply, struct rpc_task *task); extern void nfs4_destroy_session(struct nfs4_session *session); extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp); +#else /* CONFIG_NFS_v4_1 */ +static inline int nfs4_setup_sequence(struct nfs_client *clp, + struct nfs4_sequence_args *args, struct nfs4_sequence_res *res, + int cache_reply, struct rpc_task *task) +{ + return 0; +} #endif /* CONFIG_NFS_V4_1 */ extern const u32 nfs4_fattr_bitmap[2]; diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index a0946a0d116e..c9618080317e 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -280,6 +280,8 @@ static void renew_lease(const struct nfs_server *server, unsigned long timestamp * If found, we mark the slot as used, update the highest_used_slotid, * and respectively set up the sequence operation args. * The slot number is returned if found, or NFS4_MAX_SLOT_TABLE otherwise. + * + * Note: must be called with under the slot_tbl_lock. */ static u8 nfs4_find_slot(struct nfs4_slot_table *tbl, struct rpc_task *task) @@ -288,7 +290,6 @@ nfs4_find_slot(struct nfs4_slot_table *tbl, struct rpc_task *task) u8 ret_id = NFS4_MAX_SLOT_TABLE; BUILD_BUG_ON((u8)NFS4_MAX_SLOT_TABLE != (int)NFS4_MAX_SLOT_TABLE); - spin_lock(&tbl->slot_tbl_lock); dprintk("--> %s used_slots=%04lx highest_used=%d max_slots=%d\n", __func__, tbl->used_slots[0], tbl->highest_used_slotid, tbl->max_slots); @@ -302,7 +303,6 @@ nfs4_find_slot(struct nfs4_slot_table *tbl, struct rpc_task *task) out: dprintk("<-- %s used_slots=%04lx highest_used=%d slotid=%d \n", __func__, tbl->used_slots[0], tbl->highest_used_slotid, ret_id); - spin_unlock(&tbl->slot_tbl_lock); return ret_id; } @@ -312,12 +312,42 @@ static int nfs41_setup_sequence(struct nfs4_session *session, int cache_reply, struct rpc_task *task) { + struct nfs4_slot *slot; + struct nfs4_slot_table *tbl; + u8 slotid; + + dprintk("--> %s\n", __func__); /* slot already allocated? */ if (res->sr_slotid != NFS4_MAX_SLOT_TABLE) return 0; memset(res, 0, sizeof(*res)); res->sr_slotid = NFS4_MAX_SLOT_TABLE; + tbl = &session->fc_slot_table; + + spin_lock(&tbl->slot_tbl_lock); + slotid = nfs4_find_slot(tbl, task); + if (slotid == NFS4_MAX_SLOT_TABLE) { + rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL); + spin_unlock(&tbl->slot_tbl_lock); + dprintk("<-- %s: no free slots\n", __func__); + return -EAGAIN; + } + spin_unlock(&tbl->slot_tbl_lock); + + slot = tbl->slots + slotid; + args->sa_slotid = slotid; + args->sa_cache_this = cache_reply; + + dprintk("<-- %s slotid=%d seqid=%d\n", __func__, slotid, slot->seq_nr); + + res->sr_slotid = slotid; + res->sr_renewal_time = jiffies; + /* + * sr_status is only set in decode_sequence, and so will remain + * set to 1 if an rpc level failure occurs. + */ + res->sr_status = 1; return 0; } diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h index db0d1236aae7..4ac14b40efc9 100644 --- a/include/linux/nfs_xdr.h +++ b/include/linux/nfs_xdr.h @@ -163,11 +163,15 @@ struct nfs4_slot { struct nfs4_sequence_args { struct nfs4_session *sa_session; + u8 sa_slotid; + u8 sa_cache_this; }; struct nfs4_sequence_res { struct nfs4_session *sr_session; u8 sr_slotid; /* slot used to send request */ + unsigned long sr_renewal_time; + int sr_status; /* sequence operation status */ }; /* -- 2.20.1