[lvm-devel] master - pvscan: reorganize code
David Teigland
teigland at sourceware.org
Mon Apr 8 15:39:30 UTC 2019
Gitweb: https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=417724efe260723889ca4013dd7fff80bb5375c3
Commit: 417724efe260723889ca4013dd7fff80bb5375c3
Parent: 6f408f68d2094490ad28df2844889d4e9c1d1dbc
Author: David Teigland <teigland at redhat.com>
AuthorDate: Tue Feb 26 16:35:16 2019 -0600
Committer: David Teigland <teigland at redhat.com>
CommitterDate: Fri Apr 5 12:46:39 2019 -0500
pvscan: reorganize code
to simplify and prepare for subsequent change.
Should be no change in behavior.
---
tools/pvscan.c | 285 +++++++++++++++++++++++++++++---------------------------
1 files changed, 148 insertions(+), 137 deletions(-)
diff --git a/tools/pvscan.c b/tools/pvscan.c
index d69d919..f0944cd 100644
--- a/tools/pvscan.c
+++ b/tools/pvscan.c
@@ -860,7 +860,8 @@ static int _pvscan_aa(struct cmd_context *cmd, struct pvscan_aa_params *pp,
int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
{
struct pvscan_aa_params pp = { 0 };
- struct dm_list single_devs;
+ struct dm_list add_devs;
+ struct dm_list rem_devs;
struct dm_list vgnames;
struct dm_list *complete_vgnames = NULL;
struct device *dev;
@@ -870,6 +871,7 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
int32_t major = -1;
int32_t minor = -1;
int devno_args = 0;
+ int all_devs;
struct arg_value_group_list *current_group;
dev_t devno;
int do_activate = arg_is_set(cmd, activate_ARG);
@@ -877,7 +879,8 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
int add_single_count = 0;
int ret = ECMD_PROCESSED;
- dm_list_init(&single_devs);
+ dm_list_init(&add_devs);
+ dm_list_init(&rem_devs);
dm_list_init(&vgnames);
if (do_activate)
@@ -891,89 +894,36 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
return EINVALID_CMD_LINE;
}
- _online_dir_setup();
- _online_file_setup();
-
+ if (argc || devno_args) {
+ log_verbose("pvscan devices on command line.");
+ cmd->pvscan_cache_single = 1;
+ all_devs = 0;
+ } else {
+ all_devs = 1;
+ }
+
if (!lock_vol(cmd, VG_GLOBAL, LCK_VG_READ, NULL)) {
log_error("Unable to obtain global lock.");
return ECMD_FAILED;
}
- /*
- * Scan all devices when no args are given.
- */
- if (!argc && !devno_args) {
- /*
- * pvscan --cache removes existing hints and recreates new ones.
- * We begin by clearing hints at the start of the command.
- * The pvscan_recreate_hints flag is used to enable the
- * special case hint recreation in label_scan.
- */
- cmd->pvscan_recreate_hints = 1;
- pvscan_recreate_hints_begin(cmd);
-
- _lock_online(LOCK_EX, 0);
- log_verbose("pvscan all devices for requested refresh.");
- _online_files_remove(_pvs_online_dir);
- _online_files_remove(_vgs_online_dir);
- _online_pvscan_all_devs(cmd, complete_vgnames, NULL);
- _unlock_online();
+ _online_dir_setup();
+ _online_file_setup();
- cmd->pvscan_recreate_hints = 0;
- cmd->use_hints = 0;
- goto activate;
- }
+ /* Creates a list of dev names from /dev, sysfs, etc; does not read any. */
+ dev_cache_scan();
/*
- * Initialization case:
- * lock_online ex
- * if empty
- * pvscan all
- * create pvid files
- * identify complete vgs
- * unlock_online
- * activate complete vgs
- *
- * Non-initialization case:
- * lock_online ex
- * if not empty
- * unlock_unlock
- * pvscan devs
- * create pvid files
- * identify complete vgs
- * activate complete vgs
- *
- * In the non-init case, a VG with two PVs, where both PVs appear at once,
- * two parallel pvscans for each PV create the pvid files for each PV in
- * parallel, then both pvscans see the vg has completed, and both pvscans
- * activate the VG in parallel. The first pvscan to create the vgname
- * file in vgs_online will do the activation, any others will skip it.
+ * For each device command arg (from either position or --major/--minor),
+ * decide if that device is being added to the system (a dev node exists
+ * for it in /dev), or being removed from the system (no dev node exists
+ * for it in /dev). Create entries in add_devs/rem_devs for each arg
+ * accordingly.
*/
- _lock_online(LOCK_EX, 0);
-
- if (_online_pvid_files_missing()) {
- log_verbose("pvscan all devices to initialize available PVs.");
- _online_files_remove(_pvs_online_dir);
- _online_files_remove(_vgs_online_dir);
- cmd->pvscan_cache_single = 1;
- _online_pvscan_all_devs(cmd, complete_vgnames, NULL);
- _unlock_online();
- goto activate;
- } else {
- log_verbose("pvscan only specific devices.");
- _unlock_online();
- }
+ while (argc) {
+ argc--;
- if (argc || devno_args) {
- log_verbose("pvscan devices on command line.");
- cmd->pvscan_cache_single = 1;
- }
-
- /* Creates a list of dev names from /dev, sysfs, etc; does not read any. */
- dev_cache_scan();
-
- while (argc--) {
pv_name = *argv++;
if (pv_name[0] == '/') {
if (!(dev = dev_cache_get(cmd, pv_name, cmd->filter))) {
@@ -994,7 +944,7 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
if (!(devl = dm_pool_zalloc(cmd->mem, sizeof(*devl))))
return_0;
devl->dev = dev;
- dm_list_add(&single_devs, &devl->list);
+ dm_list_add(&add_devs, &devl->list);
}
} else {
if (sscanf(pv_name, "%d:%d", &major, &minor) != 2) {
@@ -1005,7 +955,13 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
if (!(dev = dev_cache_get_by_devt(cmd, devno, cmd->filter))) {
log_debug("pvscan arg %d:%d not found.", major, minor);
- _online_pvid_file_remove_devno(major, minor);
+ if (!(dev = dm_pool_zalloc(cmd->mem, sizeof(struct device))))
+ return_0;
+ if (!(devl = dm_pool_zalloc(cmd->mem, sizeof(*devl))))
+ return_0;
+ dev->dev = devno;
+ devl->dev = dev;
+ dm_list_add(&rem_devs, &devl->list);
} else {
/*
* Scan device. This dev could still be removed
@@ -1016,41 +972,11 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
if (!(devl = dm_pool_zalloc(cmd->mem, sizeof(*devl))))
return_0;
devl->dev = dev;
- dm_list_add(&single_devs, &devl->list);
+ dm_list_add(&add_devs, &devl->list);
}
}
-
- if (sigint_caught()) {
- ret = ECMD_FAILED;
- goto_out;
- }
}
- if (!dm_list_empty(&single_devs)) {
- label_scan_devs(cmd, cmd->filter, &single_devs);
-
- dm_list_iterate_items(devl, &single_devs) {
- dev = devl->dev;
-
- if (dev->flags & DEV_FILTER_OUT_SCAN)
- continue;
-
- add_single_count++;
-
- /*
- * Devices that exist and pass the lvmetad filter
- * are online.
- */
- if (!_online_pvscan_one(cmd, dev, NULL, complete_vgnames, 0, &pvid_without_metadata))
- add_errors++;
- }
- }
-
- if (!devno_args)
- goto activate;
-
- dm_list_init(&single_devs);
-
/* Process any grouped --major --minor args */
dm_list_iterate_items(current_group, &cmd->arg_value_groups) {
major = grouped_arg_int_value(current_group->arg_values, major_ARG, major);
@@ -1063,26 +989,114 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
if (!(dev = dev_cache_get_by_devt(cmd, devno, cmd->filter))) {
log_debug("pvscan arg %d:%d not found.", major, minor);
- _online_pvid_file_remove_devno(major, minor);
+ if (!(dev = dm_pool_zalloc(cmd->mem, sizeof(struct device))))
+ return_0;
+ if (!(devl = dm_pool_zalloc(cmd->mem, sizeof(*devl))))
+ return_0;
+ dev->dev = devno;
+ devl->dev = dev;
+ dm_list_add(&rem_devs, &devl->list);
} else {
log_debug("pvscan arg %d:%d found.", major, minor);
if (!(devl = dm_pool_zalloc(cmd->mem, sizeof(*devl))))
return_0;
devl->dev = dev;
- dm_list_add(&single_devs, &devl->list);
+ dm_list_add(&add_devs, &devl->list);
}
+ }
- if (sigint_caught()) {
- ret = ECMD_FAILED;
- goto_out;
- }
+ /*
+ * No device args means rescan/regenerate/[reactivate] everything.
+ * Scan all devices when no args are given; clear all pvid
+ * files on recreate pvid files for existing devices.
+ * When -aay is set, any complete vg is activated
+ * (even if it's already active.)
+ */
+
+ if (all_devs) {
+ /*
+ * pvscan --cache removes existing hints and recreates new ones.
+ * We begin by clearing hints at the start of the command.
+ * The pvscan_recreate_hints flag is used to enable the
+ * special case hint recreation in label_scan.
+ */
+ cmd->pvscan_recreate_hints = 1;
+ pvscan_recreate_hints_begin(cmd);
+
+ _lock_online(LOCK_EX, 0);
+ log_verbose("pvscan all devices for requested refresh.");
+ _online_files_remove(_pvs_online_dir);
+ _online_files_remove(_vgs_online_dir);
+ _online_pvscan_all_devs(cmd, complete_vgnames, NULL);
+ _unlock_online();
+
+ cmd->pvscan_recreate_hints = 0;
+ cmd->use_hints = 0;
+ goto activate;
}
- if (!dm_list_empty(&single_devs)) {
- label_scan_devs(cmd, cmd->filter, &single_devs);
+ /*
+ * Initialization case:
+ * lock_online ex
+ * if empty
+ * pvscan all
+ * create pvid files
+ * identify complete vgs
+ * unlock_online
+ * activate complete vgs
+ *
+ * Non-initialization case:
+ * lock_online ex
+ * if not empty
+ * unlock_unlock
+ * pvscan devs
+ * create pvid files
+ * identify complete vgs
+ * activate complete vgs
+ *
+ * In the non-init case, a VG with two PVs, where both PVs appear at once,
+ * two parallel pvscans for each PV create the pvid files for each PV in
+ * parallel, then both pvscans see the vg has completed, and both pvscans
+ * activate the VG in parallel. The first pvscan to create the vgname
+ * file in vgs_online will do the activation, any others will skip it.
+ */
+
+ _lock_online(LOCK_EX, 0);
+
+ if (_online_pvid_files_missing()) {
+ log_verbose("pvscan all devices to initialize available PVs.");
+ _online_files_remove(_pvs_online_dir);
+ _online_files_remove(_vgs_online_dir);
+ _online_pvscan_all_devs(cmd, complete_vgnames, NULL);
+ _unlock_online();
+ goto activate;
+ }
+
+ _unlock_online();
+ log_verbose("pvscan only specific devices add %d rem %d.",
+ dm_list_size(&add_devs), dm_list_size(&rem_devs));
+
+ /*
+ * Unlink online files for devices that no longer have a device node.
+ * When unlinking a pvid file for dev, we don't need to scan the dev
+ * (we can't since it's gone), but we know which pvid file it is
+ * because the major:minor are saved in the pvid files which we can
+ * read to find the correct one.
+ */
+ dm_list_iterate_items(devl, &rem_devs)
+ _online_pvid_file_remove_devno((int)MAJOR(devl->dev->dev), (int)MINOR(devl->dev->dev));
+
+ /*
+ * Create online files for devices that exist and pass the filter.
+ * When creating a pvid file for a dev, we have to scan it first
+ * to know that it's ours and what its pvid is (and which vg it
+ * belongs to if we want to do autoactivation.)
+ */
+ if (!dm_list_empty(&add_devs)) {
+ label_scan_devs(cmd, cmd->filter, &add_devs);
- dm_list_iterate_items(devl, &single_devs) {
+ dm_list_iterate_items(devl, &add_devs) {
dev = devl->dev;
if (dev->flags & DEV_FILTER_OUT_SCAN)
@@ -1090,16 +1104,27 @@ int pvscan_cache_cmd(struct cmd_context *cmd, int argc, char **argv)
add_single_count++;
- /*
- * Devices that exist and pass the lvmetad filter
- * are online.
- */
- if (!_online_pvscan_one(cmd, devl->dev, NULL, complete_vgnames, 0, &pvid_without_metadata))
+ if (!_online_pvscan_one(cmd, dev, NULL, complete_vgnames, 0, &pvid_without_metadata))
add_errors++;
}
}
-activate:
+ /*
+ * After scanning only specific devs to add a device, there is a
+ * special case that requires us to then scan all devs. That is when
+ * the dev scanned has no VG metadata, and it's the final device to
+ * complete the VG. In this case we want to autoactivate the VG, but
+ * the scanned device does not know what VG it's in or whether that VG
+ * is now complete. In this case we need to scan all devs and pick out
+ * the complete VG holding this device so we can then autoactivate that
+ * VG.
+ */
+ if (!dm_list_empty(&add_devs) && complete_vgnames && dm_list_empty(complete_vgnames) &&
+ pvid_without_metadata && do_activate) {
+ log_verbose("pvscan all devices for PV without metadata: %s.", pvid_without_metadata);
+ _online_pvscan_all_devs(cmd, complete_vgnames, &add_devs);
+ }
+
/*
* When a new PV appears, the system runs pvscan --cache dev.
* This also means that existing hints are invalid, and
@@ -1110,20 +1135,7 @@ activate:
if (add_single_count)
invalidate_hints(cmd);
- /*
- * Special case: pvscan --cache -aay dev
- * where dev has no VG metadata, and it's the final device to
- * complete the VG. In this case we want to autoactivate the
- * VG, but the scanned device does not know what VG it's in or
- * whether that VG is now complete. In this case we need to
- * scan all devs and pick out the complete VG holding this
- * device so we can then autoactivate that VG.
- */
- if (!dm_list_empty(&single_devs) && complete_vgnames && dm_list_empty(complete_vgnames) &&
- pvid_without_metadata && do_activate) {
- log_verbose("pvscan all devices for PV without metadata: %s.", pvid_without_metadata);
- _online_pvscan_all_devs(cmd, complete_vgnames, &single_devs);
- }
+activate:
/*
* Step 2: when the PV was recorded online, we check if all the
@@ -1133,7 +1145,6 @@ activate:
if (do_activate)
ret = _pvscan_aa(cmd, &pp, complete_vgnames);
-out:
if (add_errors || pp.activate_errors)
ret = ECMD_FAILED;
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