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1 | /* |
1 | /* |
2 | * Copyright (c) 2008 Jakub Jermar |
2 | * Copyright (c) 2008 Jakub Jermar |
3 | * All rights reserved. |
3 | * All rights reserved. |
4 | * |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
7 | * are met: |
8 | * |
8 | * |
9 | * - Redistributions of source code must retain the above copyright |
9 | * - Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * - Redistributions in binary form must reproduce the above copyright |
11 | * - Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
13 | * documentation and/or other materials provided with the distribution. |
14 | * - The name of the author may not be used to endorse or promote products |
14 | * - The name of the author may not be used to endorse or promote products |
15 | * derived from this software without specific prior written permission. |
15 | * derived from this software without specific prior written permission. |
16 | * |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
27 | */ |
28 | 28 | ||
29 | /** @addtogroup fs |
29 | /** @addtogroup fs |
30 | * @{ |
30 | * @{ |
31 | */ |
31 | */ |
32 | 32 | ||
33 | /** |
33 | /** |
34 | * @file vfs_lookup.c |
34 | * @file vfs_lookup.c |
35 | * @brief |
35 | * @brief |
36 | */ |
36 | */ |
37 | 37 | ||
38 | #include "vfs.h" |
38 | #include "vfs.h" |
39 | #include <ipc/ipc.h> |
39 | #include <ipc/ipc.h> |
40 | #include <async.h> |
40 | #include <async.h> |
41 | #include <errno.h> |
41 | #include <errno.h> |
42 | #include <string.h> |
42 | #include <string.h> |
43 | #include <stdarg.h> |
43 | #include <stdarg.h> |
44 | #include <bool.h> |
44 | #include <bool.h> |
45 | #include <futex.h> |
45 | #include <futex.h> |
46 | #include <libadt/list.h> |
46 | #include <libadt/list.h> |
47 | #include <vfs/canonify.h> |
47 | #include <vfs/canonify.h> |
48 | 48 | ||
49 | #define min(a, b) ((a) < (b) ? (a) : (b)) |
49 | #define min(a, b) ((a) < (b) ? (a) : (b)) |
50 | 50 | ||
51 | futex_t plb_futex = FUTEX_INITIALIZER; |
51 | futex_t plb_futex = FUTEX_INITIALIZER; |
52 | link_t plb_head; /**< PLB entry ring buffer. */ |
52 | link_t plb_head; /**< PLB entry ring buffer. */ |
53 | uint8_t *plb = NULL; |
53 | uint8_t *plb = NULL; |
54 | 54 | ||
55 | /** Perform a path lookup. |
55 | /** Perform a path lookup. |
56 | * |
56 | * |
57 | * @param path Path to be resolved; it must be a NULL-terminated |
57 | * @param path Path to be resolved; it must be a NULL-terminated |
58 | * string. |
58 | * string. |
59 | * @param lflag Flags to be used during lookup. |
59 | * @param lflag Flags to be used during lookup. |
60 | * @param result Empty structure where the lookup result will be stored. |
60 | * @param result Empty structure where the lookup result will be stored. |
61 | * Can be NULL. |
61 | * Can be NULL. |
62 | * @param altroot If non-empty, will be used instead of rootfs as the root |
62 | * @param altroot If non-empty, will be used instead of rootfs as the root |
63 | * of the whole VFS tree. |
63 | * of the whole VFS tree. |
- | 64 | * |
|
- | 65 | * @return EOK on success or an error code from errno.h. |
|
64 | * |
66 | * |
65 | * @return EOK on success or an error code from errno.h. |
- | |
66 | */ |
67 | */ |
67 | int vfs_lookup_internal(char *path, int lflag, vfs_lookup_res_t *result, |
68 | int vfs_lookup_internal(char *path, int lflag, vfs_lookup_res_t *result, |
68 | vfs_pair_t *altroot, ...) |
69 | vfs_pair_t *altroot, ...) |
69 | { |
70 | { |
70 | vfs_pair_t *root; |
71 | vfs_pair_t *root; |
71 | 72 | ||
72 | if (altroot) |
73 | if (altroot) |
73 | root = altroot; |
74 | root = altroot; |
74 | else |
75 | else |
75 | root = &rootfs; |
76 | root = &rootfs; |
76 | 77 | ||
77 | if (!root->fs_handle) |
78 | if (!root->fs_handle) |
78 | return ENOENT; |
79 | return ENOENT; |
79 | 80 | ||
80 | size_t len; |
81 | size_t len; |
81 | path = canonify(path, &len); |
82 | path = canonify(path, &len); |
82 | if (!path) |
83 | if (!path) |
83 | return EINVAL; |
84 | return EINVAL; |
84 | 85 | ||
85 | fs_index_t index = 0; |
86 | fs_index_t index = 0; |
86 | if (lflag & L_LINK) { |
87 | if (lflag & L_LINK) { |
87 | va_list ap; |
88 | va_list ap; |
88 | 89 | ||
89 | va_start(ap, altroot); |
90 | va_start(ap, altroot); |
90 | index = va_arg(ap, fs_index_t); |
91 | index = va_arg(ap, fs_index_t); |
91 | va_end(ap); |
92 | va_end(ap); |
92 | } |
93 | } |
93 | 94 | ||
94 | futex_down(&plb_futex); |
95 | futex_down(&plb_futex); |
95 | 96 | ||
96 | plb_entry_t entry; |
97 | plb_entry_t entry; |
97 | link_initialize(&entry.plb_link); |
98 | link_initialize(&entry.plb_link); |
98 | entry.len = len; |
99 | entry.len = len; |
99 | 100 | ||
100 | off_t first; /* the first free index */ |
101 | off_t first; /* the first free index */ |
101 | off_t last; /* the last free index */ |
102 | off_t last; /* the last free index */ |
102 | 103 | ||
103 | if (list_empty(&plb_head)) { |
104 | if (list_empty(&plb_head)) { |
104 | first = 0; |
105 | first = 0; |
105 | last = PLB_SIZE - 1; |
106 | last = PLB_SIZE - 1; |
106 | } else { |
107 | } else { |
107 | plb_entry_t *oldest = list_get_instance(plb_head.next, |
108 | plb_entry_t *oldest = list_get_instance(plb_head.next, |
108 | plb_entry_t, plb_link); |
109 | plb_entry_t, plb_link); |
109 | plb_entry_t *newest = list_get_instance(plb_head.prev, |
110 | plb_entry_t *newest = list_get_instance(plb_head.prev, |
110 | plb_entry_t, plb_link); |
111 | plb_entry_t, plb_link); |
111 | 112 | ||
112 | first = (newest->index + newest->len) % PLB_SIZE; |
113 | first = (newest->index + newest->len) % PLB_SIZE; |
113 | last = (oldest->index - 1) % PLB_SIZE; |
114 | last = (oldest->index - 1) % PLB_SIZE; |
114 | } |
115 | } |
115 | 116 | ||
116 | if (first <= last) { |
117 | if (first <= last) { |
117 | if ((last - first) + 1 < len) { |
118 | if ((last - first) + 1 < len) { |
118 | /* |
119 | /* |
119 | * The buffer cannot absorb the path. |
120 | * The buffer cannot absorb the path. |
120 | */ |
121 | */ |
121 | futex_up(&plb_futex); |
122 | futex_up(&plb_futex); |
122 | return ELIMIT; |
123 | return ELIMIT; |
123 | } |
124 | } |
124 | } else { |
125 | } else { |
125 | if (PLB_SIZE - ((first - last) + 1) < len) { |
126 | if (PLB_SIZE - ((first - last) + 1) < len) { |
126 | /* |
127 | /* |
127 | * The buffer cannot absorb the path. |
128 | * The buffer cannot absorb the path. |
128 | */ |
129 | */ |
129 | futex_up(&plb_futex); |
130 | futex_up(&plb_futex); |
130 | return ELIMIT; |
131 | return ELIMIT; |
131 | } |
132 | } |
132 | } |
133 | } |
133 | 134 | ||
134 | /* |
135 | /* |
135 | * We know the first free index in PLB and we also know that there is |
136 | * We know the first free index in PLB and we also know that there is |
136 | * enough space in the buffer to hold our path. |
137 | * enough space in the buffer to hold our path. |
137 | */ |
138 | */ |
138 | 139 | ||
139 | entry.index = first; |
140 | entry.index = first; |
140 | entry.len = len; |
141 | entry.len = len; |
141 | 142 | ||
142 | /* |
143 | /* |
143 | * Claim PLB space by inserting the entry into the PLB entry ring |
144 | * Claim PLB space by inserting the entry into the PLB entry ring |
144 | * buffer. |
145 | * buffer. |
145 | */ |
146 | */ |
146 | list_append(&entry.plb_link, &plb_head); |
147 | list_append(&entry.plb_link, &plb_head); |
147 | 148 | ||
148 | futex_up(&plb_futex); |
149 | futex_up(&plb_futex); |
149 | 150 | ||
150 | /* |
151 | /* |
151 | * Copy the path into PLB. |
152 | * Copy the path into PLB. |
152 | */ |
153 | */ |
153 | size_t cnt1 = min(len, (PLB_SIZE - first) + 1); |
154 | size_t cnt1 = min(len, (PLB_SIZE - first) + 1); |
154 | size_t cnt2 = len - cnt1; |
155 | size_t cnt2 = len - cnt1; |
155 | 156 | ||
156 | memcpy(&plb[first], path, cnt1); |
157 | memcpy(&plb[first], path, cnt1); |
157 | memcpy(plb, &path[cnt1], cnt2); |
158 | memcpy(plb, &path[cnt1], cnt2); |
158 | 159 | ||
159 | ipc_call_t answer; |
160 | ipc_call_t answer; |
160 | int phone = vfs_grab_phone(root->fs_handle); |
161 | int phone = vfs_grab_phone(root->fs_handle); |
161 | aid_t req = async_send_5(phone, VFS_LOOKUP, (ipcarg_t) first, |
162 | aid_t req = async_send_5(phone, VFS_LOOKUP, (ipcarg_t) first, |
162 | (ipcarg_t) (first + len - 1) % PLB_SIZE, |
163 | (ipcarg_t) (first + len - 1) % PLB_SIZE, |
163 | (ipcarg_t) root->dev_handle, (ipcarg_t) lflag, (ipcarg_t) index, |
164 | (ipcarg_t) root->dev_handle, (ipcarg_t) lflag, (ipcarg_t) index, |
164 | &answer); |
165 | &answer); |
165 | vfs_release_phone(phone); |
166 | vfs_release_phone(phone); |
166 | 167 | ||
167 | async_serialize_start(); |
168 | async_serialize_start(); |
168 | ipcarg_t rc; |
169 | ipcarg_t rc; |
169 | async_wait_for(req, &rc); |
170 | async_wait_for(req, &rc); |
170 | async_serialize_end(); |
171 | async_serialize_end(); |
171 | 172 | ||
172 | futex_down(&plb_futex); |
173 | futex_down(&plb_futex); |
173 | list_remove(&entry.plb_link); |
174 | list_remove(&entry.plb_link); |
174 | /* |
175 | /* |
175 | * Erasing the path from PLB will come handy for debugging purposes. |
176 | * Erasing the path from PLB will come handy for debugging purposes. |
176 | */ |
177 | */ |
177 | memset(&plb[first], 0, cnt1); |
178 | memset(&plb[first], 0, cnt1); |
178 | memset(plb, 0, cnt2); |
179 | memset(plb, 0, cnt2); |
179 | futex_up(&plb_futex); |
180 | futex_up(&plb_futex); |
180 | 181 | ||
181 | if ((rc == EOK) && result) { |
182 | if ((rc == EOK) && (result)) { |
182 | result->triplet.fs_handle = (fs_handle_t) IPC_GET_ARG1(answer); |
183 | result->triplet.fs_handle = (fs_handle_t) IPC_GET_ARG1(answer); |
183 | result->triplet.dev_handle = (dev_handle_t) IPC_GET_ARG2(answer); |
184 | result->triplet.dev_handle = (dev_handle_t) IPC_GET_ARG2(answer); |
184 | result->triplet.index = (fs_index_t) IPC_GET_ARG3(answer); |
185 | result->triplet.index = (fs_index_t) IPC_GET_ARG3(answer); |
185 | result->size = (size_t) IPC_GET_ARG4(answer); |
186 | result->size = (size_t) IPC_GET_ARG4(answer); |
186 | result->lnkcnt = (unsigned) IPC_GET_ARG5(answer); |
187 | result->lnkcnt = (unsigned) IPC_GET_ARG5(answer); |
187 | if (lflag & L_FILE) |
188 | if (lflag & L_FILE) |
188 | result->type = VFS_NODE_FILE; |
189 | result->type = VFS_NODE_FILE; |
189 | else if (lflag & L_DIRECTORY) |
190 | else if (lflag & L_DIRECTORY) |
190 | result->type = VFS_NODE_DIRECTORY; |
191 | result->type = VFS_NODE_DIRECTORY; |
191 | else |
192 | else |
192 | result->type = VFS_NODE_UNKNOWN; |
193 | result->type = VFS_NODE_UNKNOWN; |
193 | } |
194 | } |
194 | 195 | ||
195 | return rc; |
196 | return rc; |
- | 197 | } |
|
- | 198 | ||
- | 199 | /** Perform a node open operation. |
|
- | 200 | * |
|
- | 201 | * @return EOK on success or an error code from errno.h. |
|
- | 202 | * |
|
- | 203 | */ |
|
- | 204 | int vfs_open_node_internal(vfs_lookup_res_t *result) |
|
- | 205 | { |
|
- | 206 | int phone = vfs_grab_phone(result->triplet.fs_handle); |
|
- | 207 | ||
- | 208 | ipc_call_t answer; |
|
- | 209 | aid_t req = async_send_2(phone, VFS_OPEN_NODE, |
|
- | 210 | (ipcarg_t) result->triplet.dev_handle, |
|
- | 211 | (ipcarg_t) result->triplet.index, &answer); |
|
- | 212 | ||
- | 213 | vfs_release_phone(phone); |
|
- | 214 | ||
- | 215 | async_serialize_start(); |
|
- | 216 | ipcarg_t rc; |
|
- | 217 | async_wait_for(req, &rc); |
|
- | 218 | async_serialize_end(); |
|
- | 219 | ||
- | 220 | if (rc == EOK) { |
|
- | 221 | result->size = (size_t) IPC_GET_ARG1(answer); |
|
- | 222 | result->lnkcnt = (unsigned) IPC_GET_ARG2(answer); |
|
- | 223 | if (IPC_GET_ARG3(answer) & L_FILE) |
|
- | 224 | result->type = VFS_NODE_FILE; |
|
- | 225 | else if (IPC_GET_ARG3(answer) & L_DIRECTORY) |
|
- | 226 | result->type = VFS_NODE_DIRECTORY; |
|
- | 227 | else |
|
- | 228 | result->type = VFS_NODE_UNKNOWN; |
|
- | 229 | } |
|
- | 230 | ||
- | 231 | return rc; |
|
196 | } |
232 | } |
197 | 233 | ||
198 | /** |
234 | /** |
199 | * @} |
235 | * @} |
200 | */ |
236 | */ |
201 | 237 |