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author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2005-06-22 17:16:32 (GMT) |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2005-06-22 20:07:42 (GMT) |
commit | 8d0a8a9d0ec790086c64d210af413ac351d89e35 (patch) | |
tree | 003a1481e4a8d8487956a6bf04db80dd93264b8b /fs/nfs/nfs4state.c | |
parent | ecdbf769b2cb8903e07cd482334c714d89fd1146 (diff) | |
download | linux-8d0a8a9d0ec790086c64d210af413ac351d89e35.tar.xz |
[PATCH] NFSv4: Clean up nfs4 lock state accounting
Ensure that lock owner structures are not released prematurely.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4state.c')
-rw-r--r-- | fs/nfs/nfs4state.c | 178 |
1 files changed, 79 insertions, 99 deletions
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 591ad1d..afe587d 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -360,7 +360,7 @@ nfs4_alloc_open_state(void) atomic_set(&state->count, 1); INIT_LIST_HEAD(&state->lock_states); init_MUTEX(&state->lock_sema); - rwlock_init(&state->state_lock); + spin_lock_init(&state->state_lock); return state; } @@ -542,16 +542,6 @@ __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner) return NULL; } -struct nfs4_lock_state * -nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner) -{ - struct nfs4_lock_state *lsp; - read_lock(&state->state_lock); - lsp = __nfs4_find_lock_state(state, fl_owner); - read_unlock(&state->state_lock); - return lsp; -} - /* * Return a compatible lock_state. If no initialized lock_state structure * exists, return an uninitialized one. @@ -568,14 +558,13 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f return NULL; lsp->ls_flags = 0; lsp->ls_seqid = 0; /* arbitrary */ - lsp->ls_id = -1; memset(lsp->ls_stateid.data, 0, sizeof(lsp->ls_stateid.data)); atomic_set(&lsp->ls_count, 1); lsp->ls_owner = fl_owner; - INIT_LIST_HEAD(&lsp->ls_locks); spin_lock(&clp->cl_lock); lsp->ls_id = nfs4_alloc_lockowner_id(clp); spin_unlock(&clp->cl_lock); + INIT_LIST_HEAD(&lsp->ls_locks); return lsp; } @@ -585,121 +574,112 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f * * The caller must be holding state->lock_sema and clp->cl_sem */ -struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner) +static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner) { - struct nfs4_lock_state * lsp; + struct nfs4_lock_state *lsp, *new = NULL; - lsp = nfs4_find_lock_state(state, owner); - if (lsp == NULL) - lsp = nfs4_alloc_lock_state(state, owner); + for(;;) { + spin_lock(&state->state_lock); + lsp = __nfs4_find_lock_state(state, owner); + if (lsp != NULL) + break; + if (new != NULL) { + new->ls_state = state; + list_add(&new->ls_locks, &state->lock_states); + set_bit(LK_STATE_IN_USE, &state->flags); + lsp = new; + new = NULL; + break; + } + spin_unlock(&state->state_lock); + new = nfs4_alloc_lock_state(state, owner); + if (new == NULL) + return NULL; + } + spin_unlock(&state->state_lock); + kfree(new); return lsp; } /* - * Byte-range lock aware utility to initialize the stateid of read/write - * requests. + * Release reference to lock_state, and free it if we see that + * it is no longer in use */ -void -nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner) +static void nfs4_put_lock_state(struct nfs4_lock_state *lsp) { - if (test_bit(LK_STATE_IN_USE, &state->flags)) { - struct nfs4_lock_state *lsp; + struct nfs4_state *state; - lsp = nfs4_find_lock_state(state, fl_owner); - if (lsp) { - memcpy(dst, &lsp->ls_stateid, sizeof(*dst)); - nfs4_put_lock_state(lsp); - return; - } - } - memcpy(dst, &state->stateid, sizeof(*dst)); + if (lsp == NULL) + return; + state = lsp->ls_state; + if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock)) + return; + list_del(&lsp->ls_locks); + if (list_empty(&state->lock_states)) + clear_bit(LK_STATE_IN_USE, &state->flags); + spin_unlock(&state->state_lock); + kfree(lsp); } -/* -* Called with state->lock_sema and clp->cl_sem held. -*/ -void nfs4_increment_lock_seqid(int status, struct nfs4_lock_state *lsp) +static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src) { - if (status == NFS_OK || seqid_mutating_err(-status)) - lsp->ls_seqid++; -} + struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner; -/* -* Check to see if the request lock (type FL_UNLK) effects the fl lock. -* -* fl and request must have the same posix owner -* -* return: -* 0 -> fl not effected by request -* 1 -> fl consumed by request -*/ + dst->fl_u.nfs4_fl.owner = lsp; + atomic_inc(&lsp->ls_count); +} -static int -nfs4_check_unlock(struct file_lock *fl, struct file_lock *request) +static void nfs4_fl_release_lock(struct file_lock *fl) { - if (fl->fl_start >= request->fl_start && fl->fl_end <= request->fl_end) - return 1; - return 0; + nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner); } -/* - * Post an initialized lock_state on the state->lock_states list. - */ -void nfs4_notify_setlk(struct nfs4_state *state, struct file_lock *request, struct nfs4_lock_state *lsp) +static struct file_lock_operations nfs4_fl_lock_ops = { + .fl_copy_lock = nfs4_fl_copy_lock, + .fl_release_private = nfs4_fl_release_lock, +}; + +int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl) { - if (!list_empty(&lsp->ls_locks)) - return; - atomic_inc(&lsp->ls_count); - write_lock(&state->state_lock); - list_add(&lsp->ls_locks, &state->lock_states); - set_bit(LK_STATE_IN_USE, &state->flags); - write_unlock(&state->state_lock); + struct nfs4_lock_state *lsp; + + if (fl->fl_ops != NULL) + return 0; + lsp = nfs4_get_lock_state(state, fl->fl_owner); + if (lsp == NULL) + return -ENOMEM; + fl->fl_u.nfs4_fl.owner = lsp; + fl->fl_ops = &nfs4_fl_lock_ops; + return 0; } -/* - * to decide to 'reap' lock state: - * 1) search i_flock for file_locks with fl.lock_state = to ls. - * 2) determine if unlock will consume found lock. - * if so, reap - * - * else, don't reap. - * +/* + * Byte-range lock aware utility to initialize the stateid of read/write + * requests. */ -void -nfs4_notify_unlck(struct nfs4_state *state, struct file_lock *request, struct nfs4_lock_state *lsp) +void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner) { - struct inode *inode = state->inode; - struct file_lock *fl; + struct nfs4_lock_state *lsp; - for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { - if (!(fl->fl_flags & FL_POSIX)) - continue; - if (fl->fl_owner != lsp->ls_owner) - continue; - /* Exit if we find at least one lock which is not consumed */ - if (nfs4_check_unlock(fl,request) == 0) - return; - } + memcpy(dst, &state->stateid, sizeof(*dst)); + if (test_bit(LK_STATE_IN_USE, &state->flags) == 0) + return; - write_lock(&state->state_lock); - list_del_init(&lsp->ls_locks); - if (list_empty(&state->lock_states)) - clear_bit(LK_STATE_IN_USE, &state->flags); - write_unlock(&state->state_lock); + spin_lock(&state->state_lock); + lsp = __nfs4_find_lock_state(state, fl_owner); + if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0) + memcpy(dst, &lsp->ls_stateid, sizeof(*dst)); + spin_unlock(&state->state_lock); nfs4_put_lock_state(lsp); } /* - * Release reference to lock_state, and free it if we see that - * it is no longer in use - */ -void -nfs4_put_lock_state(struct nfs4_lock_state *lsp) +* Called with state->lock_sema and clp->cl_sem held. +*/ +void nfs4_increment_lock_seqid(int status, struct nfs4_lock_state *lsp) { - if (!atomic_dec_and_test(&lsp->ls_count)) - return; - BUG_ON (!list_empty(&lsp->ls_locks)); - kfree(lsp); + if (status == NFS_OK || seqid_mutating_err(-status)) + lsp->ls_seqid++; } /* |