+static enum cl_lock_mode cl_mode_user_to_kernel(enum lock_mode_user mode)
+{
+ switch (mode) {
+ case MODE_READ_USER:
+ return CLM_READ;
+ case MODE_WRITE_USER:
+ return CLM_WRITE;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const char *const user_lockname[] = LOCK_MODE_NAMES;
+
+/* Used to allow the upper layers of the client to request an LDLM lock
+ * without doing an actual read or write.
+ *
+ * Used for ladvise lockahead to manually request specific locks.
+ *
+ * \param[in] file file this ladvise lock request is on
+ * \param[in] ladvise ladvise struct describing this lock request
+ *
+ * \retval 0 success, no detailed result available (sync requests
+ * and requests sent to the server [not handled locally]
+ * cannot return detailed results)
+ * \retval LLA_RESULT_{SAME,DIFFERENT} - detailed result of the lock request,
+ * see definitions for details.
+ * \retval negative negative errno on error
+ */
+int ll_file_lock_ahead(struct file *file, struct llapi_lu_ladvise *ladvise)
+{
+ struct lu_env *env = NULL;
+ struct cl_io *io = NULL;
+ struct cl_lock *lock = NULL;
+ struct cl_lock_descr *descr = NULL;
+ struct dentry *dentry = file->f_path.dentry;
+ struct inode *inode = dentry->d_inode;
+ enum cl_lock_mode cl_mode;
+ off_t start = ladvise->lla_start;
+ off_t end = ladvise->lla_end;
+ int result;
+ __u16 refcheck;
+
+ ENTRY;
+
+ CDEBUG(D_VFSTRACE, "Lock request: file=%.*s, inode=%p, mode=%s "
+ "start=%llu, end=%llu\n", dentry->d_name.len,
+ dentry->d_name.name, dentry->d_inode,
+ user_lockname[ladvise->lla_lockahead_mode], (__u64) start,
+ (__u64) end);
+
+ cl_mode = cl_mode_user_to_kernel(ladvise->lla_lockahead_mode);
+ if (cl_mode < 0)
+ GOTO(out, result = cl_mode);
+
+ /* Get IO environment */
+ result = cl_io_get(inode, &env, &io, &refcheck);
+ if (result <= 0)
+ GOTO(out, result);
+
+ result = cl_io_init(env, io, CIT_MISC, io->ci_obj);
+ if (result > 0) {
+ /*
+ * nothing to do for this io. This currently happens when
+ * stripe sub-object's are not yet created.
+ */
+ result = io->ci_result;
+ } else if (result == 0) {
+ lock = vvp_env_lock(env);
+ descr = &lock->cll_descr;
+
+ descr->cld_obj = io->ci_obj;
+ /* Convert byte offsets to pages */
+ descr->cld_start = cl_index(io->ci_obj, start);
+ descr->cld_end = cl_index(io->ci_obj, end);
+ descr->cld_mode = cl_mode;
+ /* CEF_MUST is used because we do not want to convert a
+ * lockahead request to a lockless lock */
+ descr->cld_enq_flags = CEF_MUST | CEF_LOCK_NO_EXPAND |
+ CEF_NONBLOCK;
+
+ if (ladvise->lla_peradvice_flags & LF_ASYNC)
+ descr->cld_enq_flags |= CEF_SPECULATIVE;
+
+ result = cl_lock_request(env, io, lock);
+
+ /* On success, we need to release the lock */
+ if (result >= 0)
+ cl_lock_release(env, lock);
+ }
+ cl_io_fini(env, io);
+ cl_env_put(env, &refcheck);
+
+ /* -ECANCELED indicates a matching lock with a different extent
+ * was already present, and -EEXIST indicates a matching lock
+ * on exactly the same extent was already present.
+ * We convert them to positive values for userspace to make
+ * recognizing true errors easier.
+ * Note we can only return these detailed results on async requests,
+ * as sync requests look the same as i/o requests for locking. */
+ if (result == -ECANCELED)
+ result = LLA_RESULT_DIFFERENT;
+ else if (result == -EEXIST)
+ result = LLA_RESULT_SAME;
+
+out:
+ RETURN(result);
+}
+static const char *const ladvise_names[] = LU_LADVISE_NAMES;
+
+static int ll_ladvise_sanity(struct inode *inode,
+ struct llapi_lu_ladvise *ladvise)
+{
+ enum lu_ladvise_type advice = ladvise->lla_advice;
+ /* Note the peradvice flags is a 32 bit field, so per advice flags must
+ * be in the first 32 bits of enum ladvise_flags */
+ __u32 flags = ladvise->lla_peradvice_flags;
+ /* 3 lines at 80 characters per line, should be plenty */
+ int rc = 0;
+
+ if (advice > LU_LADVISE_MAX || advice == LU_LADVISE_INVALID) {
+ rc = -EINVAL;
+ CDEBUG(D_VFSTRACE, "%s: advice with value '%d' not recognized,"
+ "last supported advice is %s (value '%d'): rc = %d\n",
+ ll_get_fsname(inode->i_sb, NULL, 0), advice,
+ ladvise_names[LU_LADVISE_MAX-1], LU_LADVISE_MAX-1, rc);
+ GOTO(out, rc);
+ }
+
+ /* Per-advice checks */
+ switch (advice) {
+ case LU_LADVISE_LOCKNOEXPAND:
+ if (flags & ~LF_LOCKNOEXPAND_MASK) {
+ rc = -EINVAL;
+ CDEBUG(D_VFSTRACE, "%s: Invalid flags (%x) for %s: "
+ "rc = %d\n",
+ ll_get_fsname(inode->i_sb, NULL, 0), flags,
+ ladvise_names[advice], rc);
+ GOTO(out, rc);
+ }
+ break;
+ case LU_LADVISE_LOCKAHEAD:
+ /* Currently only READ and WRITE modes can be requested */
+ if (ladvise->lla_lockahead_mode >= MODE_MAX_USER ||
+ ladvise->lla_lockahead_mode == 0) {
+ rc = -EINVAL;
+ CDEBUG(D_VFSTRACE, "%s: Invalid mode (%d) for %s: "
+ "rc = %d\n",
+ ll_get_fsname(inode->i_sb, NULL, 0),
+ ladvise->lla_lockahead_mode,
+ ladvise_names[advice], rc);
+ GOTO(out, rc);
+ }
+ case LU_LADVISE_WILLREAD:
+ case LU_LADVISE_DONTNEED:
+ default:
+ /* Note fall through above - These checks apply to all advices
+ * except LOCKNOEXPAND */
+ if (flags & ~LF_DEFAULT_MASK) {
+ rc = -EINVAL;
+ CDEBUG(D_VFSTRACE, "%s: Invalid flags (%x) for %s: "
+ "rc = %d\n",
+ ll_get_fsname(inode->i_sb, NULL, 0), flags,
+ ladvise_names[advice], rc);
+ GOTO(out, rc);
+ }
+ if (ladvise->lla_start >= ladvise->lla_end) {
+ rc = -EINVAL;
+ CDEBUG(D_VFSTRACE, "%s: Invalid range (%llu to %llu) "
+ "for %s: rc = %d\n",
+ ll_get_fsname(inode->i_sb, NULL, 0),
+ ladvise->lla_start, ladvise->lla_end,
+ ladvise_names[advice], rc);
+ GOTO(out, rc);
+ }
+ break;
+ }
+
+out:
+ return rc;
+}
+#undef ERRSIZE
+
git://git.whamcloud.com / fs / lustre-release.git / blobdiff