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e1455744 DW |
1 | /* |
2 | * Copyright(c) 2013-2015 Intel Corporation. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of version 2 of the GNU General Public License as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | */ | |
13 | #include <linux/device.h> | |
14 | #include <linux/sizes.h> | |
15 | #include "nd-core.h" | |
16 | #include "pfn.h" | |
17 | #include "btt.h" | |
18 | #include "nd.h" | |
19 | ||
20 | void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns) | |
21 | { | |
22 | struct nd_namespace_common *ndns = *_ndns; | |
23 | ||
24 | dev_WARN_ONCE(dev, !mutex_is_locked(&ndns->dev.mutex) | |
25 | || ndns->claim != dev, | |
26 | "%s: invalid claim\n", __func__); | |
27 | ndns->claim = NULL; | |
28 | *_ndns = NULL; | |
29 | put_device(&ndns->dev); | |
30 | } | |
31 | ||
32 | void nd_detach_ndns(struct device *dev, | |
33 | struct nd_namespace_common **_ndns) | |
34 | { | |
35 | struct nd_namespace_common *ndns = *_ndns; | |
36 | ||
37 | if (!ndns) | |
38 | return; | |
39 | get_device(&ndns->dev); | |
40 | device_lock(&ndns->dev); | |
41 | __nd_detach_ndns(dev, _ndns); | |
42 | device_unlock(&ndns->dev); | |
43 | put_device(&ndns->dev); | |
44 | } | |
45 | ||
46 | bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach, | |
47 | struct nd_namespace_common **_ndns) | |
48 | { | |
49 | if (attach->claim) | |
50 | return false; | |
51 | dev_WARN_ONCE(dev, !mutex_is_locked(&attach->dev.mutex) | |
52 | || *_ndns, | |
53 | "%s: invalid claim\n", __func__); | |
54 | attach->claim = dev; | |
55 | *_ndns = attach; | |
56 | get_device(&attach->dev); | |
57 | return true; | |
58 | } | |
59 | ||
60 | bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach, | |
61 | struct nd_namespace_common **_ndns) | |
62 | { | |
63 | bool claimed; | |
64 | ||
65 | device_lock(&attach->dev); | |
66 | claimed = __nd_attach_ndns(dev, attach, _ndns); | |
67 | device_unlock(&attach->dev); | |
68 | return claimed; | |
69 | } | |
70 | ||
71 | static int namespace_match(struct device *dev, void *data) | |
72 | { | |
73 | char *name = data; | |
74 | ||
75 | return strcmp(name, dev_name(dev)) == 0; | |
76 | } | |
77 | ||
78 | static bool is_idle(struct device *dev, struct nd_namespace_common *ndns) | |
79 | { | |
80 | struct nd_region *nd_region = to_nd_region(dev->parent); | |
81 | struct device *seed = NULL; | |
82 | ||
83 | if (is_nd_btt(dev)) | |
84 | seed = nd_region->btt_seed; | |
85 | else if (is_nd_pfn(dev)) | |
86 | seed = nd_region->pfn_seed; | |
87 | ||
88 | if (seed == dev || ndns || dev->driver) | |
89 | return false; | |
90 | return true; | |
91 | } | |
92 | ||
93 | static void nd_detach_and_reset(struct device *dev, | |
94 | struct nd_namespace_common **_ndns) | |
95 | { | |
96 | /* detach the namespace and destroy / reset the device */ | |
97 | nd_detach_ndns(dev, _ndns); | |
98 | if (is_idle(dev, *_ndns)) { | |
99 | nd_device_unregister(dev, ND_ASYNC); | |
100 | } else if (is_nd_btt(dev)) { | |
101 | struct nd_btt *nd_btt = to_nd_btt(dev); | |
102 | ||
103 | nd_btt->lbasize = 0; | |
104 | kfree(nd_btt->uuid); | |
105 | nd_btt->uuid = NULL; | |
106 | } else if (is_nd_pfn(dev)) { | |
107 | struct nd_pfn *nd_pfn = to_nd_pfn(dev); | |
108 | ||
109 | kfree(nd_pfn->uuid); | |
110 | nd_pfn->uuid = NULL; | |
111 | nd_pfn->mode = PFN_MODE_NONE; | |
112 | } | |
113 | } | |
114 | ||
115 | ssize_t nd_namespace_store(struct device *dev, | |
116 | struct nd_namespace_common **_ndns, const char *buf, | |
117 | size_t len) | |
118 | { | |
119 | struct nd_namespace_common *ndns; | |
120 | struct device *found; | |
121 | char *name; | |
122 | ||
123 | if (dev->driver) { | |
124 | dev_dbg(dev, "%s: -EBUSY\n", __func__); | |
125 | return -EBUSY; | |
126 | } | |
127 | ||
128 | name = kstrndup(buf, len, GFP_KERNEL); | |
129 | if (!name) | |
130 | return -ENOMEM; | |
131 | strim(name); | |
132 | ||
133 | if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0) | |
134 | /* pass */; | |
135 | else { | |
136 | len = -EINVAL; | |
137 | goto out; | |
138 | } | |
139 | ||
140 | ndns = *_ndns; | |
141 | if (strcmp(name, "") == 0) { | |
142 | nd_detach_and_reset(dev, _ndns); | |
143 | goto out; | |
144 | } else if (ndns) { | |
145 | dev_dbg(dev, "namespace already set to: %s\n", | |
146 | dev_name(&ndns->dev)); | |
147 | len = -EBUSY; | |
148 | goto out; | |
149 | } | |
150 | ||
151 | found = device_find_child(dev->parent, name, namespace_match); | |
152 | if (!found) { | |
153 | dev_dbg(dev, "'%s' not found under %s\n", name, | |
154 | dev_name(dev->parent)); | |
155 | len = -ENODEV; | |
156 | goto out; | |
157 | } | |
158 | ||
159 | ndns = to_ndns(found); | |
160 | if (__nvdimm_namespace_capacity(ndns) < SZ_16M) { | |
161 | dev_dbg(dev, "%s too small to host\n", name); | |
162 | len = -ENXIO; | |
163 | goto out_attach; | |
164 | } | |
165 | ||
166 | WARN_ON_ONCE(!is_nvdimm_bus_locked(dev)); | |
167 | if (!nd_attach_ndns(dev, ndns, _ndns)) { | |
168 | dev_dbg(dev, "%s already claimed\n", | |
169 | dev_name(&ndns->dev)); | |
170 | len = -EBUSY; | |
171 | } | |
172 | ||
173 | out_attach: | |
174 | put_device(&ndns->dev); /* from device_find_child */ | |
175 | out: | |
176 | kfree(name); | |
177 | return len; | |
178 | } | |
179 | ||
180 | /* | |
181 | * nd_sb_checksum: compute checksum for a generic info block | |
182 | * | |
183 | * Returns a fletcher64 checksum of everything in the given info block | |
184 | * except the last field (since that's where the checksum lives). | |
185 | */ | |
186 | u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb) | |
187 | { | |
188 | u64 sum; | |
189 | __le64 sum_save; | |
190 | ||
191 | BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K); | |
192 | BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K); | |
193 | BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K); | |
194 | ||
195 | sum_save = nd_gen_sb->checksum; | |
196 | nd_gen_sb->checksum = 0; | |
197 | sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1); | |
198 | nd_gen_sb->checksum = sum_save; | |
199 | return sum; | |
200 | } | |
201 | EXPORT_SYMBOL(nd_sb_checksum); |