4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * (C) Copyright 2017 Commissariat a l'energie atomique et aux energies
9 * All rights reserved. This program and the accompanying materials
10 * are made available under the terms of the GNU Lesser General Public License
11 * (LGPL) version 2.1 or (at your discretion) any later version.
12 * (LGPL) version 2.1 accompanies this distribution, and is available at
13 * http://www.gnu.org/licenses/lgpl-2.1.html
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
23 * lustre/utils/liblustreapi_chlg.c
25 * lustreapi library for filesystem changelog
27 * Author: Henri Doreau <henri.doreau@cea.fr>
38 #include <sys/types.h>
40 #include <lustre/lustreapi.h>
43 static int chlg_dev_path(char *path, size_t path_len, const char *device)
47 rc = snprintf(path, path_len, "/dev/changelog-%s", device);
57 #define CHANGELOG_PRIV_MAGIC 0xCA8E1080
58 #define CHANGELOG_BUFFER_SZ 4096
61 * Record state for efficient changelog consumption.
62 * Read chunks of CHANGELOG_BUFFER_SZ bytes.
64 struct changelog_private {
65 /* Ensure that the structure is valid and initialized */
67 /* File descriptor on the changelog character device */
69 /* Changelog delivery mode */
70 enum changelog_send_flag clp_send_flags;
71 /* Changelog extra flags */
72 enum changelog_send_extra_flag clp_send_extra_flags;
73 /* Available bytes in buffer */
75 /* Current position in buffer */
77 /* Read buffer with records read from system */
82 * Start reading from a changelog
84 * @param priv Opaque private control structure
85 * @param flags Start flags (e.g. CHANGELOG_FLAG_JOBID)
86 * @param device Report changes recorded on this MDT
87 * @param startrec Report changes beginning with this record number
88 * (just call llapi_changelog_fini when done; don't need an endrec)
90 int llapi_changelog_start(void **priv, enum changelog_send_flag flags,
91 const char *device, long long startrec)
93 struct changelog_private *cp;
94 static bool warned_extra_flags;
95 static bool warned_jobid;
96 static bool warned_follow;
97 char cdev_path[PATH_MAX];
100 rc = chlg_dev_path(cdev_path, sizeof(cdev_path), device);
104 /* Set up the receiver control struct */
105 cp = calloc(1, sizeof(*cp) + CHANGELOG_BUFFER_SZ);
109 cp->clp_magic = CHANGELOG_PRIV_MAGIC;
110 cp->clp_send_flags = flags;
113 cp->clp_buf_pos = cp->clp_buf;
115 /* Set up the receiver */
116 cp->clp_fd = open(cdev_path, O_RDONLY);
117 if (cp->clp_fd < 0) {
125 res = lseek(cp->clp_fd, startrec, SEEK_SET);
126 if (res == (off_t)-1) {
134 /* CHANGELOG_FLAG_EXTRA_FLAGS will eventually become mandatory.
135 * If it wasn't specified, display a warning here.
136 * Code elsewhere will remove the corresponding extension.
138 if (!(flags & CHANGELOG_FLAG_EXTRA_FLAGS) && !warned_extra_flags) {
139 llapi_err_noerrno(LLAPI_MSG_WARN,
140 "warning: %s() called without CHANGELOG_FLAG_EXTRA_FLAGS",
142 warned_extra_flags = true;
145 /* CHANGELOG_FLAG_JOBID will eventually become mandatory. Display a
146 * warning if it's missing. */
147 if (!(flags & CHANGELOG_FLAG_JOBID) && !warned_jobid) {
148 llapi_err_noerrno(LLAPI_MSG_WARN, "warning: %s() called "
149 "without CHANGELOG_FLAG_JOBID", __func__);
153 /* Behavior expected by CHANGELOG_FLAG_FOLLOW is not implemented, warn
154 * the user and ignore it. */
155 if (flags & CHANGELOG_FLAG_FOLLOW && !warned_follow) {
156 llapi_err_noerrno(LLAPI_MSG_WARN, "warning: %s() called with "
157 "CHANGELOG_FLAG_FOLLOW (ignored)", __func__);
158 warned_follow = true;
170 /** Finish reading from a changelog */
171 int llapi_changelog_fini(void **priv)
173 struct changelog_private *cp = *priv;
175 if (!cp || (cp->clp_magic != CHANGELOG_PRIV_MAGIC))
184 static ssize_t chlg_read_bulk(struct changelog_private *cp)
188 if (!cp || cp->clp_magic != CHANGELOG_PRIV_MAGIC)
191 rd_bytes = read(cp->clp_fd, cp->clp_buf, CHANGELOG_BUFFER_SZ);
195 cp->clp_buf_pos = cp->clp_buf;
196 cp->clp_buf_len = rd_bytes;
202 * Returns a file descriptor to poll on.
204 * \@param[in] priv Opaque changelog reader structure.
205 * @return valid file descriptor on success, negated errno code on failure.
207 int llapi_changelog_get_fd(void *priv)
209 struct changelog_private *cp = priv;
211 if (!cp || cp->clp_magic != CHANGELOG_PRIV_MAGIC)
217 /** Read the next changelog entry
218 * @param priv Opaque private control structure
219 * @param rech Changelog record handle; record will be allocated here
220 * @return 0 valid message received; rec is set
224 #define DEFAULT_RECORD_FMT (CLF_VERSION | CLF_RENAME)
225 int llapi_changelog_recv(void *priv, struct changelog_rec **rech)
227 struct changelog_private *cp = priv;
228 enum changelog_rec_flags rec_fmt = DEFAULT_RECORD_FMT;
229 enum changelog_rec_extra_flags rec_extra_fmt = CLFE_INVALID;
230 struct changelog_rec *tmp;
233 if (!cp || (cp->clp_magic != CHANGELOG_PRIV_MAGIC))
239 *rech = malloc(CR_MAXSIZE);
243 if (cp->clp_send_flags & CHANGELOG_FLAG_JOBID)
244 rec_fmt |= CLF_JOBID;
246 if (cp->clp_send_flags & CHANGELOG_FLAG_EXTRA_FLAGS) {
247 rec_fmt |= CLF_EXTRA_FLAGS;
248 if (cp->clp_send_extra_flags & CHANGELOG_EXTRA_FLAG_UIDGID)
249 rec_extra_fmt |= CLFE_UIDGID;
252 if (cp->clp_buf + cp->clp_buf_len <= cp->clp_buf_pos) {
255 refresh = chlg_read_bulk(cp);
257 /* EOF, CHANGELOG_FLAG_FOLLOW ignored for now LU-7659 */
260 } else if (refresh < 0) {
266 /* TODO check changelog_rec_size */
267 tmp = (struct changelog_rec *)cp->clp_buf_pos;
269 memcpy(*rech, cp->clp_buf_pos,
270 changelog_rec_size(tmp) + tmp->cr_namelen);
272 cp->clp_buf_pos += changelog_rec_size(tmp) + tmp->cr_namelen;
273 changelog_remap_rec(*rech, rec_fmt, rec_extra_fmt);
283 /** Release the changelog record when done with it. */
284 int llapi_changelog_free(struct changelog_rec **rech)
291 int llapi_changelog_clear(const char *mdtname, const char *idstr,
294 char dev_path[PATH_MAX];
296 size_t cmd_len = sizeof(cmd);
301 llapi_err_noerrno(LLAPI_MSG_ERROR,
302 "can't purge negative records\n");
306 chlg_dev_path(dev_path, sizeof(dev_path), mdtname);
308 rc = snprintf(cmd, cmd_len, "clear:%s:%lld", idstr, endrec);
309 if (rc >= sizeof(cmd))
314 fd = open(dev_path, O_WRONLY);
317 llapi_error(LLAPI_MSG_ERROR, rc, "cannot open '%s'", dev_path);
321 rc = write(fd, cmd, cmd_len);
324 llapi_error(LLAPI_MSG_ERROR, rc,
325 "cannot purge records for '%s'", idstr);
337 * Set extra flags for reading changelogs
339 * @param priv Opaque private control structure
340 * @param extra_flags Read extra flags (e.g. CHANGELOG_EXTRA_FLAG_UIDGID)
342 * Just call this function right after llapi_changelog_start().
344 int llapi_changelog_set_xflags(void *priv,
345 enum changelog_send_extra_flag extra_flags)
347 struct changelog_private *cp = priv;
348 static bool warned_uidgid;
350 if (!cp || cp->clp_magic != CHANGELOG_PRIV_MAGIC)
353 cp->clp_send_extra_flags = extra_flags;
355 /* CHANGELOG_EXTRA_FLAG_UIDGID will eventually become mandatory.
356 * If it wasn't specified, display a warning here.
357 * Code elsewhere will remove the corresponding extension.
359 if (!(extra_flags & CHANGELOG_EXTRA_FLAG_UIDGID) && !warned_uidgid) {
360 llapi_err_noerrno(LLAPI_MSG_WARN,
361 "warning: %s() called without CHANGELOG_EXTRA_FLAG_UIDGID",
363 warned_uidgid = true;