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29 * This file is part of Lustre, http://www.lustre.org/
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32 * Implementation of cl_lock for LOV layer.
34 * Author: Nikita Danilov <nikita.danilov@sun.com>
37 #define DEBUG_SUBSYSTEM S_LOV
39 #include "lov_cl_internal.h"
45 /*****************************************************************************
47 * Lov lock operations.
51 static struct lov_sublock_env *lov_sublock_env_get(const struct lu_env *env,
52 const struct cl_lock *parent,
53 struct lov_lock_sub *lls)
55 struct lov_sublock_env *subenv;
56 struct lov_io *lio = lov_env_io(env);
57 struct cl_io *io = lio->lis_cl.cis_io;
58 struct lov_io_sub *sub;
60 subenv = &lov_env_session(env)->ls_subenv;
63 * FIXME: We tend to use the subio's env & io to call the sublock
64 * lock operations because osc lock sometimes stores some control
65 * variables in thread's IO information(Now only lockless information).
66 * However, if the lock's host(object) is different from the object
67 * for current IO, we have no way to get the subenv and subio because
68 * they are not initialized at all. As a temp fix, in this case,
69 * we still borrow the parent's env to call sublock operations.
71 if (!io || !cl_object_same(io->ci_obj, parent->cll_descr.cld_obj)) {
72 subenv->lse_env = env;
74 subenv->lse_sub = NULL;
76 sub = lov_sub_get(env, lio, lls->sub_stripe);
78 subenv->lse_env = sub->sub_env;
79 subenv->lse_io = sub->sub_io;
80 subenv->lse_sub = sub;
88 static void lov_sublock_env_put(struct lov_sublock_env *subenv)
90 if (subenv && subenv->lse_sub)
91 lov_sub_put(subenv->lse_sub);
94 static int lov_sublock_init(const struct lu_env *env,
95 const struct cl_lock *parent,
96 struct lov_lock_sub *lls)
98 struct lov_sublock_env *subenv;
101 subenv = lov_sublock_env_get(env, parent, lls);
102 if (!IS_ERR(subenv)) {
103 result = cl_lock_init(subenv->lse_env, &lls->sub_lock,
105 lov_sublock_env_put(subenv);
108 result = PTR_ERR(subenv);
114 * Creates sub-locks for a given lov_lock for the first time.
116 * Goes through all sub-objects of top-object, and creates sub-locks on every
117 * sub-object intersecting with top-lock extent. This is complicated by the
118 * fact that top-lock (that is being created) can be accessed concurrently
119 * through already created sub-locks (possibly shared with other top-locks).
121 static struct lov_lock *lov_lock_sub_init(const struct lu_env *env,
122 const struct cl_object *obj,
123 struct cl_lock *lock)
133 struct lov_object *loo = cl2lov(obj);
134 struct lov_layout_raid0 *r0 = lov_r0(loo);
135 struct lov_lock *lovlck;
137 file_start = cl_offset(lov2cl(loo), lock->cll_descr.cld_start);
138 file_end = cl_offset(lov2cl(loo), lock->cll_descr.cld_end + 1) - 1;
140 for (i = 0, nr = 0; i < r0->lo_nr; i++) {
142 * XXX for wide striping smarter algorithm is desirable,
143 * breaking out of the loop, early.
145 if (likely(r0->lo_sub[i]) && /* spare layout */
146 lov_stripe_intersects(loo->lo_lsm, i,
147 file_start, file_end, &start, &end))
151 lovlck = libcfs_kvzalloc(offsetof(struct lov_lock, lls_sub[nr]),
154 return ERR_PTR(-ENOMEM);
157 for (i = 0, nr = 0; i < r0->lo_nr; ++i) {
158 if (likely(r0->lo_sub[i]) &&
159 lov_stripe_intersects(loo->lo_lsm, i,
160 file_start, file_end, &start, &end)) {
161 struct lov_lock_sub *lls = &lovlck->lls_sub[nr];
162 struct cl_lock_descr *descr;
164 descr = &lls->sub_lock.cll_descr;
166 LASSERT(!descr->cld_obj);
167 descr->cld_obj = lovsub2cl(r0->lo_sub[i]);
168 descr->cld_start = cl_index(descr->cld_obj, start);
169 descr->cld_end = cl_index(descr->cld_obj, end);
170 descr->cld_mode = lock->cll_descr.cld_mode;
171 descr->cld_gid = lock->cll_descr.cld_gid;
172 descr->cld_enq_flags = lock->cll_descr.cld_enq_flags;
175 /* initialize sub lock */
176 result = lov_sublock_init(env, lock, lls);
180 lls->sub_initialized = 1;
184 LASSERT(ergo(result == 0, nr == lovlck->lls_nr));
187 for (i = 0; i < nr; ++i) {
188 if (!lovlck->lls_sub[i].sub_initialized)
191 cl_lock_fini(env, &lovlck->lls_sub[i].sub_lock);
194 lovlck = ERR_PTR(result);
200 static void lov_lock_fini(const struct lu_env *env,
201 struct cl_lock_slice *slice)
203 struct lov_lock *lovlck;
206 lovlck = cl2lov_lock(slice);
207 for (i = 0; i < lovlck->lls_nr; ++i) {
208 LASSERT(!lovlck->lls_sub[i].sub_is_enqueued);
209 if (lovlck->lls_sub[i].sub_initialized)
210 cl_lock_fini(env, &lovlck->lls_sub[i].sub_lock);
216 * Implementation of cl_lock_operations::clo_enqueue() for lov layer. This
217 * function is rather subtle, as it enqueues top-lock (i.e., advances top-lock
218 * state machine from CLS_QUEUING to CLS_ENQUEUED states) by juggling sub-lock
219 * state machines in the face of sub-locks sharing (by multiple top-locks),
220 * and concurrent sub-lock cancellations.
222 static int lov_lock_enqueue(const struct lu_env *env,
223 const struct cl_lock_slice *slice,
224 struct cl_io *io, struct cl_sync_io *anchor)
226 struct cl_lock *lock = slice->cls_lock;
227 struct lov_lock *lovlck = cl2lov_lock(slice);
231 for (i = 0; i < lovlck->lls_nr; ++i) {
232 struct lov_lock_sub *lls = &lovlck->lls_sub[i];
233 struct lov_sublock_env *subenv;
235 subenv = lov_sublock_env_get(env, lock, lls);
236 if (IS_ERR(subenv)) {
237 rc = PTR_ERR(subenv);
240 rc = cl_lock_enqueue(subenv->lse_env, subenv->lse_io,
241 &lls->sub_lock, anchor);
242 lov_sublock_env_put(subenv);
246 lls->sub_is_enqueued = 1;
251 static void lov_lock_cancel(const struct lu_env *env,
252 const struct cl_lock_slice *slice)
254 struct cl_lock *lock = slice->cls_lock;
255 struct lov_lock *lovlck = cl2lov_lock(slice);
258 for (i = 0; i < lovlck->lls_nr; ++i) {
259 struct lov_lock_sub *lls = &lovlck->lls_sub[i];
260 struct cl_lock *sublock = &lls->sub_lock;
261 struct lov_sublock_env *subenv;
263 if (!lls->sub_is_enqueued)
266 lls->sub_is_enqueued = 0;
267 subenv = lov_sublock_env_get(env, lock, lls);
268 if (!IS_ERR(subenv)) {
269 cl_lock_cancel(subenv->lse_env, sublock);
270 lov_sublock_env_put(subenv);
272 CL_LOCK_DEBUG(D_ERROR, env, slice->cls_lock,
273 "lov_lock_cancel fails with %ld.\n",
279 static int lov_lock_print(const struct lu_env *env, void *cookie,
280 lu_printer_t p, const struct cl_lock_slice *slice)
282 struct lov_lock *lck = cl2lov_lock(slice);
285 (*p)(env, cookie, "%d\n", lck->lls_nr);
286 for (i = 0; i < lck->lls_nr; ++i) {
287 struct lov_lock_sub *sub;
289 sub = &lck->lls_sub[i];
290 (*p)(env, cookie, " %d %x: ", i, sub->sub_is_enqueued);
291 cl_lock_print(env, cookie, p, &sub->sub_lock);
296 static const struct cl_lock_operations lov_lock_ops = {
297 .clo_fini = lov_lock_fini,
298 .clo_enqueue = lov_lock_enqueue,
299 .clo_cancel = lov_lock_cancel,
300 .clo_print = lov_lock_print
303 int lov_lock_init_raid0(const struct lu_env *env, struct cl_object *obj,
304 struct cl_lock *lock, const struct cl_io *io)
306 struct lov_lock *lck;
309 lck = lov_lock_sub_init(env, obj, lock);
311 cl_lock_slice_add(lock, &lck->lls_cl, obj, &lov_lock_ops);
313 result = PTR_ERR(lck);
317 static void lov_empty_lock_fini(const struct lu_env *env,
318 struct cl_lock_slice *slice)
320 struct lov_lock *lck = cl2lov_lock(slice);
322 kmem_cache_free(lov_lock_kmem, lck);
325 static int lov_empty_lock_print(const struct lu_env *env, void *cookie,
327 const struct cl_lock_slice *slice)
329 (*p)(env, cookie, "empty\n");
333 /* XXX: more methods will be added later. */
334 static const struct cl_lock_operations lov_empty_lock_ops = {
335 .clo_fini = lov_empty_lock_fini,
336 .clo_print = lov_empty_lock_print
339 int lov_lock_init_empty(const struct lu_env *env, struct cl_object *obj,
340 struct cl_lock *lock, const struct cl_io *io)
342 struct lov_lock *lck;
343 int result = -ENOMEM;
345 lck = kmem_cache_zalloc(lov_lock_kmem, GFP_NOFS);
347 cl_lock_slice_add(lock, &lck->lls_cl, obj, &lov_empty_lock_ops);