4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
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21 * CA 95054 USA or visit www.sun.com if you need additional information or
27 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
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32 * Lustre is a trademark of Sun Microsystems, Inc.
35 #define DEBUG_SUBSYSTEM S_FILTER
38 #include <linux/jbd.h>
39 #include <linux/module.h>
40 #include <linux/kmod.h>
41 #include <linux/slab.h>
42 #include <libcfs/libcfs.h>
43 #include <lustre_fsfilt.h>
45 CFS_LIST_HEAD(fsfilt_types);
47 static struct fsfilt_operations *fsfilt_search_type(const char *type)
49 struct fsfilt_operations *found;
52 cfs_list_for_each(p, &fsfilt_types) {
53 found = cfs_list_entry(p, struct fsfilt_operations, fs_list);
54 if (!strcmp(found->fs_type, type)) {
61 int fsfilt_register_ops(struct fsfilt_operations *fs_ops)
63 struct fsfilt_operations *found;
65 /* lock fsfilt_types list */
66 if ((found = fsfilt_search_type(fs_ops->fs_type))) {
67 if (found != fs_ops) {
68 CERROR("different operations for type %s\n",
70 /* unlock fsfilt_types list */
75 cfs_list_add(&fs_ops->fs_list, &fsfilt_types);
78 /* unlock fsfilt_types list */
81 EXPORT_SYMBOL(fsfilt_register_ops);
83 void fsfilt_unregister_ops(struct fsfilt_operations *fs_ops)
87 /* lock fsfilt_types list */
88 cfs_list_for_each(p, &fsfilt_types) {
89 struct fsfilt_operations *found;
91 found = cfs_list_entry(p, typeof(*found), fs_list);
92 if (found == fs_ops) {
98 /* unlock fsfilt_types list */
100 EXPORT_SYMBOL(fsfilt_unregister_ops);
102 struct fsfilt_operations *fsfilt_get_ops(const char *type)
104 struct fsfilt_operations *fs_ops;
106 /* lock fsfilt_types list */
107 if (!(fs_ops = fsfilt_search_type(type))) {
111 snprintf(name, sizeof(name) - 1, "fsfilt_%s", type);
112 name[sizeof(name) - 1] = '\0';
114 if (!(rc = cfs_request_module("%s", name))) {
115 fs_ops = fsfilt_search_type(type);
116 CDEBUG(D_INFO, "Loaded module '%s'\n", name);
122 CERROR("Can't find %s interface\n", name);
123 RETURN(ERR_PTR(rc < 0 ? rc : -rc));
124 /* unlock fsfilt_types list */
127 cfs_try_module_get(fs_ops->fs_owner);
128 /* unlock fsfilt_types list */
132 EXPORT_SYMBOL(fsfilt_get_ops);
134 void fsfilt_put_ops(struct fsfilt_operations *fs_ops)
136 cfs_module_put(fs_ops->fs_owner);
138 EXPORT_SYMBOL(fsfilt_put_ops);