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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;
75 sub = lov_sub_get(env, lio, lls->sub_stripe);
77 subenv->lse_env = sub->sub_env;
78 subenv->lse_io = sub->sub_io;
86 static int lov_sublock_init(const struct lu_env *env,
87 const struct cl_lock *parent,
88 struct lov_lock_sub *lls)
90 struct lov_sublock_env *subenv;
93 subenv = lov_sublock_env_get(env, parent, lls);
94 if (!IS_ERR(subenv)) {
95 result = cl_lock_init(subenv->lse_env, &lls->sub_lock,
99 result = PTR_ERR(subenv);
105 * Creates sub-locks for a given lov_lock for the first time.
107 * Goes through all sub-objects of top-object, and creates sub-locks on every
108 * sub-object intersecting with top-lock extent. This is complicated by the
109 * fact that top-lock (that is being created) can be accessed concurrently
110 * through already created sub-locks (possibly shared with other top-locks).
112 static struct lov_lock *lov_lock_sub_init(const struct lu_env *env,
113 const struct cl_object *obj,
114 struct cl_lock *lock)
124 struct lov_object *loo = cl2lov(obj);
125 struct lov_layout_raid0 *r0 = lov_r0(loo);
126 struct lov_lock *lovlck;
128 CDEBUG(D_INODE, "%p: lock/io FID " DFID "/" DFID ", lock/io clobj %p/%p\n",
129 loo, PFID(lu_object_fid(lov2lu(loo))),
130 PFID(lu_object_fid(&obj->co_lu)),
133 file_start = cl_offset(lov2cl(loo), lock->cll_descr.cld_start);
134 file_end = cl_offset(lov2cl(loo), lock->cll_descr.cld_end + 1) - 1;
136 for (i = 0, nr = 0; i < r0->lo_nr; i++) {
138 * XXX for wide striping smarter algorithm is desirable,
139 * breaking out of the loop, early.
141 if (likely(r0->lo_sub[i]) && /* spare layout */
142 lov_stripe_intersects(loo->lo_lsm, i,
143 file_start, file_end, &start, &end))
147 lovlck = libcfs_kvzalloc(offsetof(struct lov_lock, lls_sub[nr]),
150 return ERR_PTR(-ENOMEM);
153 for (i = 0, nr = 0; i < r0->lo_nr; ++i) {
154 if (likely(r0->lo_sub[i]) &&
155 lov_stripe_intersects(loo->lo_lsm, i,
156 file_start, file_end, &start, &end)) {
157 struct lov_lock_sub *lls = &lovlck->lls_sub[nr];
158 struct cl_lock_descr *descr;
160 descr = &lls->sub_lock.cll_descr;
162 LASSERT(!descr->cld_obj);
163 descr->cld_obj = lovsub2cl(r0->lo_sub[i]);
164 descr->cld_start = cl_index(descr->cld_obj, start);
165 descr->cld_end = cl_index(descr->cld_obj, end);
166 descr->cld_mode = lock->cll_descr.cld_mode;
167 descr->cld_gid = lock->cll_descr.cld_gid;
168 descr->cld_enq_flags = lock->cll_descr.cld_enq_flags;
171 /* initialize sub lock */
172 result = lov_sublock_init(env, lock, lls);
176 lls->sub_initialized = 1;
180 LASSERT(ergo(result == 0, nr == lovlck->lls_nr));
183 for (i = 0; i < nr; ++i) {
184 if (!lovlck->lls_sub[i].sub_initialized)
187 cl_lock_fini(env, &lovlck->lls_sub[i].sub_lock);
190 lovlck = ERR_PTR(result);
196 static void lov_lock_fini(const struct lu_env *env,
197 struct cl_lock_slice *slice)
199 struct lov_lock *lovlck;
202 lovlck = cl2lov_lock(slice);
203 for (i = 0; i < lovlck->lls_nr; ++i) {
204 LASSERT(!lovlck->lls_sub[i].sub_is_enqueued);
205 if (lovlck->lls_sub[i].sub_initialized)
206 cl_lock_fini(env, &lovlck->lls_sub[i].sub_lock);
212 * Implementation of cl_lock_operations::clo_enqueue() for lov layer. This
213 * function is rather subtle, as it enqueues top-lock (i.e., advances top-lock
214 * state machine from CLS_QUEUING to CLS_ENQUEUED states) by juggling sub-lock
215 * state machines in the face of sub-locks sharing (by multiple top-locks),
216 * and concurrent sub-lock cancellations.
218 static int lov_lock_enqueue(const struct lu_env *env,
219 const struct cl_lock_slice *slice,
220 struct cl_io *io, struct cl_sync_io *anchor)
222 struct cl_lock *lock = slice->cls_lock;
223 struct lov_lock *lovlck = cl2lov_lock(slice);
227 for (i = 0; i < lovlck->lls_nr; ++i) {
228 struct lov_lock_sub *lls = &lovlck->lls_sub[i];
229 struct lov_sublock_env *subenv;
231 subenv = lov_sublock_env_get(env, lock, lls);
232 if (IS_ERR(subenv)) {
233 rc = PTR_ERR(subenv);
236 rc = cl_lock_enqueue(subenv->lse_env, subenv->lse_io,
237 &lls->sub_lock, anchor);
241 lls->sub_is_enqueued = 1;
246 static void lov_lock_cancel(const struct lu_env *env,
247 const struct cl_lock_slice *slice)
249 struct cl_lock *lock = slice->cls_lock;
250 struct lov_lock *lovlck = cl2lov_lock(slice);
253 for (i = 0; i < lovlck->lls_nr; ++i) {
254 struct lov_lock_sub *lls = &lovlck->lls_sub[i];
255 struct cl_lock *sublock = &lls->sub_lock;
256 struct lov_sublock_env *subenv;
258 if (!lls->sub_is_enqueued)
261 lls->sub_is_enqueued = 0;
262 subenv = lov_sublock_env_get(env, lock, lls);
263 if (!IS_ERR(subenv)) {
264 cl_lock_cancel(subenv->lse_env, sublock);
266 CL_LOCK_DEBUG(D_ERROR, env, slice->cls_lock,
267 "%s fails with %ld.\n",
268 __func__, PTR_ERR(subenv));
273 static int lov_lock_print(const struct lu_env *env, void *cookie,
274 lu_printer_t p, const struct cl_lock_slice *slice)
276 struct lov_lock *lck = cl2lov_lock(slice);
279 (*p)(env, cookie, "%d\n", lck->lls_nr);
280 for (i = 0; i < lck->lls_nr; ++i) {
281 struct lov_lock_sub *sub;
283 sub = &lck->lls_sub[i];
284 (*p)(env, cookie, " %d %x: ", i, sub->sub_is_enqueued);
285 cl_lock_print(env, cookie, p, &sub->sub_lock);
290 static const struct cl_lock_operations lov_lock_ops = {
291 .clo_fini = lov_lock_fini,
292 .clo_enqueue = lov_lock_enqueue,
293 .clo_cancel = lov_lock_cancel,
294 .clo_print = lov_lock_print
297 int lov_lock_init_raid0(const struct lu_env *env, struct cl_object *obj,
298 struct cl_lock *lock, const struct cl_io *io)
300 struct lov_lock *lck;
303 lck = lov_lock_sub_init(env, obj, lock);
305 cl_lock_slice_add(lock, &lck->lls_cl, obj, &lov_lock_ops);
307 result = PTR_ERR(lck);
311 static void lov_empty_lock_fini(const struct lu_env *env,
312 struct cl_lock_slice *slice)
314 struct lov_lock *lck = cl2lov_lock(slice);
316 kmem_cache_free(lov_lock_kmem, lck);
319 static int lov_empty_lock_print(const struct lu_env *env, void *cookie,
321 const struct cl_lock_slice *slice)
323 (*p)(env, cookie, "empty\n");
327 /* XXX: more methods will be added later. */
328 static const struct cl_lock_operations lov_empty_lock_ops = {
329 .clo_fini = lov_empty_lock_fini,
330 .clo_print = lov_empty_lock_print
333 int lov_lock_init_empty(const struct lu_env *env, struct cl_object *obj,
334 struct cl_lock *lock, const struct cl_io *io)
336 struct lov_lock *lck;
337 int result = -ENOMEM;
339 lck = kmem_cache_zalloc(lov_lock_kmem, GFP_NOFS);
341 cl_lock_slice_add(lock, &lck->lls_cl, obj, &lov_empty_lock_ops);