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device_id: improve searched_devnames temp file
Include info in the temp file to confirm that it should be used. The temp file is meant to suppress repeated, identical searches for the same PVIDs on the same set of devices. Write to the file a count and hash of the missing PVIDs and a count and hash of the devices to search. A subsequent command will ignore and remove the temp file if any of these values differ. We don't want to suppress a search if a change has occured, and a missing PV could be found by scanning devices.
This commit is contained in:
David Teigland
parent
2b7c832847
commit
de2b11f39a
@ -19,6 +19,7 @@
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#include "lib/device/device_id.h"
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#include "lib/device/dev-type.h"
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#include "lib/label/label.h"
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#include "lib/misc/crc.h"
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#include "lib/metadata/metadata.h"
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#include "lib/format_text/layout.h"
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#include "lib/cache/lvmcache.h"
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@ -43,6 +44,8 @@ static int _devices_file_locked;
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static char _devices_lockfile[PATH_MAX];
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static char _devices_file_version[VERSION_LINE_MAX];
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static const char *_searched_file = DEFAULT_RUN_DIR "/searched_devnames";
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static const char *_searched_file_new = DEFAULT_RUN_DIR "/searched_devnames_new";
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static const char *_searched_file_dir = DEFAULT_RUN_DIR;
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/* Only for displaying in lvmdevices command output. */
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char devices_file_hostname_orig[PATH_MAX];
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@ -53,23 +56,79 @@ char *devices_file_version(void)
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return _devices_file_version;
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}
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/*
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* cmd->devicesfile is set when using a non-system devices file,
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* and at least for now, the searched_devnames optimization
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* only applies to the system devices file.
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*/
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static void _touch_searched_devnames(struct cmd_context *cmd)
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static void _searched_devnames_create(struct cmd_context *cmd,
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int search_pvids_count, uint32_t search_pvids_hash,
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int search_devs_count, uint32_t search_devs_hash)
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{
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FILE *fp;
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time_t t;
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int dir_fd;
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int fflush_errno = 0;
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int fclose_errno = 0;
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/*
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* cmd->devicesfile is set when using a devices file other
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* than the default system.devices, and at least for now,
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* the searched_devnames temp file is only used for commands
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* using system.devices.
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*/
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if (cmd->devicesfile)
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return;
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if (!(fp = fopen(_searched_file, "w")))
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unlink(_searched_file_new); /* in case previous file was left */
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/*
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* No file lock is used to coordinate concurrent attempts to create
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* the temp file, so we expect this fopen may file sometimes.
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*/
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if (!(fp = fopen(_searched_file_new, "wx"))) {
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log_debug("searched_devnames_create error fopen %d", errno);
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return;
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}
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if ((dir_fd = open(_searched_file_dir, O_RDONLY)) < 0) {
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log_debug("searched_devnames_create error open dir %d", errno);
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fclose(fp);
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unlink(_searched_file_new);
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return;
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}
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t = time(NULL);
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/* comment to help with debugging */
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fprintf(fp, "# Created by LVM command %s pid %d system.devices %s at %s",
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cmd->name, getpid(), _devices_file_version[0] ? _devices_file_version : "none", ctime(&t));
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fprintf(fp, "pvids: %d %u\n", search_pvids_count, search_pvids_hash);
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fprintf(fp, "devs: %d %u\n", search_devs_count, search_devs_hash);
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if (fflush(fp))
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fflush_errno = errno;
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if (fclose(fp))
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fclose_errno = errno;
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if (fflush_errno || fclose_errno) {
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log_debug("searched_devnames_create error fflush %d fclose %d",
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fflush_errno, fclose_errno);
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unlink(_searched_file_new);
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close(dir_fd);
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return;
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}
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if (rename(_searched_file_new, _searched_file) < 0) {
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log_debug("searched_devnames_create error rename %d", errno);
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unlink(_searched_file_new);
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close(dir_fd);
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return;
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}
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if (fsync(dir_fd) < 0)
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stack;
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if (close(dir_fd) < 0)
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stack;
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log_debug("searched_devnames created pvids %d %u devs %d %u",
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search_pvids_count, search_pvids_hash, search_devs_count, search_devs_hash);
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}
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void unlink_searched_devnames(struct cmd_context *cmd)
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@ -83,20 +142,68 @@ void unlink_searched_devnames(struct cmd_context *cmd)
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log_debug("unlink %s", _searched_file);
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}
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static int _searched_devnames_exists(struct cmd_context *cmd)
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/*
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* Consistent hashes between commands depend on the devs and pvids being
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* processed in the same order by each command. For devs this is true because
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* we process the devs using dev_iter which is a btree ordered by devno keys.
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* For pvids this is true because the cmd->use_devices list order comes from
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* the order of lines in system.devices.
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*/
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static int _searched_devnames_exists(struct cmd_context *cmd,
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int search_pvids_count, uint32_t search_pvids_hash,
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int search_devs_count, uint32_t search_devs_hash)
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{
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struct stat buf;
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FILE *fp;
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char line[PATH_MAX];
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uint32_t pvids_hash_file = 0;
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uint32_t devs_hash_file = 0;
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int pvids_ok = 0;
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int devs_ok = 0;
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int pvids_count_file = 0;
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int devs_count_file = 0;
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int ret = 0;
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if (cmd->devicesfile)
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return 0;
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if (!stat(_searched_file, &buf))
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return 1;
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if (!(fp = fopen(_searched_file, "r")))
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return 0;
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if (errno != ENOENT)
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log_debug("stat %s errno %d", _searched_file, errno);
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return 0;
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while (fgets(line, sizeof(line), fp)) {
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if (line[0] == '#')
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continue;
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if (!strncmp(line, "pvids: ", 7)) {
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if (sscanf(line + 7, "%d %u", &pvids_count_file, &pvids_hash_file) != 2)
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goto out;
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if (pvids_count_file != search_pvids_count)
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goto out;
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if (pvids_hash_file != search_pvids_hash)
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goto out;
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pvids_ok = 1;
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} else if (!strncmp(line, "devs: ", 6)) {
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if (sscanf(line + 6, "%d %u", &devs_count_file, &devs_hash_file) != 2)
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goto out;
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if (devs_count_file != search_devs_count)
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goto out;
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if (devs_hash_file != search_devs_hash)
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goto out;
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devs_ok = 1;
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} else {
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goto out;
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}
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}
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if (pvids_ok && devs_ok)
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ret = 1;
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out:
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fclose(fp);
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log_debug("searched_devnames %s file pvids %d %u devs %d %u search pvids %d %u devs %d %u",
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ret ? "match" : "differ",
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pvids_count_file, pvids_hash_file, devs_count_file, devs_hash_file,
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search_pvids_count, search_pvids_hash, search_devs_count, search_devs_hash);
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if (!ret)
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unlink(_searched_file);
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return ret;
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}
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/*
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@ -2863,11 +2970,10 @@ void device_ids_validate(struct cmd_context *cmd, struct dm_list *scanned_devs,
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}
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/*
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* When a new devname/pvid mismatch is discovered, a new search for the
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* pvid should be permitted (searched_devnames may exist to suppress
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* searching for other pvids.)
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* When info in the devices file has become incorrect,
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* try another search for PVIDs on renamed devices.
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*/
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if (update_file || cmd->device_ids_invalid)
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if (update_file)
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unlink_searched_devnames(cmd);
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if (update_file && update_needed)
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@ -3211,8 +3317,8 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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struct dev_iter *iter;
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struct device_list *devl; /* holds struct device */
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struct device_id_list *dil, *dil2; /* holds struct device + pvid */
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struct dm_list search_list_pvids; /* list of device_id_list */
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struct dm_list search_list_devs ; /* list of device_list */
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struct dm_list search_pvids; /* list of device_id_list */
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struct dm_list search_devs; /* list of device_list */
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const char *devname;
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int update_file = 0;
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int found = 0;
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@ -3220,9 +3326,13 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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int search_mode_none;
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int search_mode_auto;
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int search_mode_all;
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int search_pvids_count = 0;
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int search_devs_count = 0;
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uint32_t search_pvids_hash = INITIAL_CRC;
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uint32_t search_devs_hash = INITIAL_CRC;
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dm_list_init(&search_list_pvids);
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dm_list_init(&search_list_devs);
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dm_list_init(&search_pvids);
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dm_list_init(&search_devs);
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if (!cmd->enable_devices_file)
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return;
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@ -3255,7 +3365,7 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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}
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/*
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* Create search_list_pvids which is a list of PVIDs that
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* Create search_pvids which is a list of PVIDs that
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* we want to locate on some device.
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*/
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dm_list_iterate_items(du, &cmd->use_devices) {
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@ -3283,42 +3393,24 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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if (!(dil = dm_pool_zalloc(cmd->mem, sizeof(*dil))))
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continue;
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memcpy(dil->pvid, du->pvid, ID_LEN);
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dm_list_add(&search_list_pvids, &dil->list);
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dm_list_add(&search_pvids, &dil->list);
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search_pvids_count++;
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search_pvids_hash = calc_crc(search_pvids_hash, (const uint8_t *)du->pvid, strlen(du->pvid));
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}
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/* No unmatched PVIDs to search for, and no system id to update. */
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if (dm_list_empty(&search_list_pvids) && !cmd->device_ids_refresh_trigger)
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if (dm_list_empty(&search_pvids) && !cmd->device_ids_refresh_trigger)
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return;
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log_debug("Search for PVIDs %d trigger %d all_ids %d search all %d auto %d none %d",
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dm_list_size(&search_list_pvids), cmd->device_ids_refresh_trigger, all_ids,
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dm_list_size(&search_pvids), cmd->device_ids_refresh_trigger, all_ids,
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search_mode_all, search_mode_auto, search_mode_none);
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if (dm_list_empty(&search_list_pvids) && cmd->device_ids_refresh_trigger) {
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if (dm_list_empty(&search_pvids) && cmd->device_ids_refresh_trigger) {
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update_file = 1;
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goto out;
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}
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/*
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* A previous command searched for devnames and found nothing, so it
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* created the searched file to tell us not to bother. Without this, a
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* device that's permanently detached (and identified by devname) would
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* cause every command to search for it. If the detached device is
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* later attached, it will generate a pvscan, and pvscan will unlink
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* the searched file, so a subsequent lvm command will do the search
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* again. In future perhaps we could add a policy to automatically
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* remove a devices file entry that's not been found for some time.
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*
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* TODO: like the hint file, add a hash of all devnames to the searched
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* file so it can be ignored and removed if the devs/hash change.
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* If hints are enabled, the hints invalidation could also remove the
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* searched file.
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*/
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if (!cmd->device_ids_refresh_trigger && !all_ids && _searched_devnames_exists(cmd)) {
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log_debug("Search for PVIDs skipped for %s", _searched_file);
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return;
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}
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/*
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* Now we want to look at devs on the system that were previously
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* rejected by filter-deviceid (based on a devname device id) to check
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@ -3349,11 +3441,30 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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if (!(devl = dm_pool_zalloc(cmd->mem, sizeof(*devl))))
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continue;
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devl->dev = dev;
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dm_list_add(&search_list_devs, &devl->list);
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dm_list_add(&search_devs, &devl->list);
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search_devs_count++;
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search_devs_hash = calc_crc(search_devs_hash, (const uint8_t *)&devl->dev->dev, sizeof(dev_t));
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}
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dev_iter_destroy(iter);
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log_debug("Search for PVIDs reading labels on %d devs.", dm_list_size(&search_list_devs));
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/*
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* A previous command searched for devnames and found nothing, so it
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* created the searched file to tell us not to bother. Without this, a
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* device that's permanently detached (and identified by devname) would
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* cause every command to search for it. If the detached device is
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* later attached, it will generate a pvscan, and pvscan will unlink
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* the searched file, so a subsequent lvm command will do the search
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* again. In future perhaps we could add a policy to automatically
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* remove a devices file entry that's not been found for some time.
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*/
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if (!cmd->device_ids_refresh_trigger && !all_ids &&
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_searched_devnames_exists(cmd, search_pvids_count, search_pvids_hash,
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search_devs_count, search_devs_hash)) {
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log_debug("Search for PVIDs skipped for matching %s", _searched_file);
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return;
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}
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log_debug("Search for PVIDs reading labels.");
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/*
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* Read the dev to get the pvid, and run the filters that will use the
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@ -3361,7 +3472,7 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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* to modify the command's existing filter chain or the persistent
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* filter values.
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*/
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dm_list_iterate_items(devl, &search_list_devs) {
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dm_list_iterate_items(devl, &search_devs) {
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int has_pvid;
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dev = devl->dev;
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@ -3422,11 +3533,11 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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/*
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* Check if the the PVID returned from label_read is one we are looking for.
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* The loop below looks at search_list_pvids entries that have dil->dev set.
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* This loop continues checking after all search_list_pvids entries have been
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* The loop below looks at search_pvids entries that have dil->dev set.
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* This loop continues checking after all search_pvids entries have been
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* matched in order to check if the PVID is on duplicate devs.
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*/
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dm_list_iterate_items_safe(dil, dil2, &search_list_pvids) {
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dm_list_iterate_items_safe(dil, dil2, &search_pvids) {
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if (!memcmp(dil->pvid, dev->pvid, ID_LEN)) {
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if (dil->dev) {
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log_warn("WARNING: found PVID %s on multiple devices %s %s.",
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@ -3447,14 +3558,14 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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/*
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* The use_devices entries (repesenting the devices file) are
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* updated for the new devices on which the PVs reside. The new
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* correct devs are set as dil->dev on search_list_pvids entries.
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* correct devs are set as dil->dev on search_pvids entries.
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*
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* The du/dev/id are set up and linked for the new devs.
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*
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* The command's full filter chain is updated for the new devs now that
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* filter-deviceid will pass.
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*/
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dm_list_iterate_items(dil, &search_list_pvids) {
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dm_list_iterate_items(dil, &search_pvids) {
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char *new_idname, *new_idname2, *new_devname;
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uint16_t new_idtype;
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@ -3522,7 +3633,7 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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update_file = 1;
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}
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dm_list_iterate_items(dil, &search_list_pvids) {
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dm_list_iterate_items(dil, &search_pvids) {
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if (!dil->dev)
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continue;
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dev = dil->dev;
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@ -3560,11 +3671,11 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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*update_needed = 1;
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/*
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* The entries in search_list_pvids with a dev set are the new devs found
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* The entries in search_pvids with a dev set are the new devs found
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* for the PVIDs that we want to return to the caller in a device_list
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* format.
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*/
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dm_list_iterate_items(dil, &search_list_pvids) {
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dm_list_iterate_items(dil, &search_pvids) {
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if (!dil->dev)
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continue;
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dev = dil->dev;
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@ -3577,11 +3688,26 @@ void device_ids_search(struct cmd_context *cmd, struct dm_list *new_devs,
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/*
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* Prevent more devname searches by subsequent commands, in case the
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* pvids not found were from devices that are permanently detached.
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* If a new PV appears, pvscan will run and do unlink_searched_file.
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* pvids not found were from devices that are permanently detached. If
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* a new PV appears, pvscan will run and do unlink_searched_file.
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* Also, if the hints code detects that the hints file becomes invalid
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* due to new system devs, then searched_devnames is also unlinked.
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* So, the searched_devnames temp file should not prevent a missing
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* device from being found if it's attached later.
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*
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* Any lvmdevices command removes searched_devnames temp file prior to
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* running, and don't create the temp file from any lvmdevices command;
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* this is not among the commands we want to optimize.
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*
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* Note: the searched_devnames temp file only suppresses searches for
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* missing PVIDs with IDTYPE=devname that may have a new device name.
|
||||
* It does not suppress searches for missing PVIDs when done for
|
||||
* refresh, where PVIDs of any idtype are searched for.
|
||||
*/
|
||||
if (!cmd->device_ids_refresh_trigger && !all_ids && not_found && !found)
|
||||
_touch_searched_devnames(cmd);
|
||||
if (!cmd->device_ids_refresh_trigger && !all_ids && not_found && !found &&
|
||||
strcmp(cmd->name, "lvmdevices"))
|
||||
_searched_devnames_create(cmd, search_pvids_count, search_pvids_hash,
|
||||
search_devs_count, search_devs_hash);
|
||||
}
|
||||
|
||||
int devices_file_touch(struct cmd_context *cmd)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user