[RFC PATCH 1/7] remove device scan from _text_create_text_instance

[RFC PATCH 1/7] remove device scan from _text_create_text_instance

[Takahiro Yasui]

Usually the _text_create_text_instance function is called after device
scan is done, and as far as I understand, lvmcache_label_scan in the
_text_create_text_instance is not necessarily needed.


Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
---
 lib/format_text/format-text.c |    2 --
 1 file changed, 2 deletions(-)

Index: LVM2.02.46-cvs-20090324/lib/format_text/format-text.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/format_text/format-text.c
+++ LVM2.02.46-cvs-20090324/lib/format_text/format-text.c
@@ -1792,8 +1792,6 @@ static struct format_instance *_text_cre
 			dm_list_add(&fid->metadata_areas, &mda->list);
 		}
 
-		/* Scan PVs in VG for any further MDAs */
-		lvmcache_label_scan(fmt->cmd, 0);
 		if (!(vginfo = vginfo_from_vgname(vgname, vgid)))
 			goto_out;
 		dm_list_iterate_items(info, &vginfo->infos) {

[RFC PATCH 2/7] rename _has_scanned to _need_scan

[Takahiro Yasui]

When metadata cache is loaded into lvmcache, no device scan is necessary,
but it does not mean "has scanned". To tell lvmcache not to scan devices,
the variable name, _has_scanned, is renamed to _need_scan and its logic
is reversed.


Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
---
 lib/cache/lvmcache.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Index: LVM2.02.46-cvs-20090324/lib/cache/lvmcache.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/cache/lvmcache.c
+++ LVM2.02.46-cvs-20090324/lib/cache/lvmcache.c
@@ -32,7 +32,7 @@ static struct dm_hash_table *_vgname_has
 static struct dm_hash_table *_lock_hash = NULL;
 static struct dm_list _vginfos;
 static int _scanning_in_progress = 0;
-static int _has_scanned = 0;
+static int _need_scan = 1;
 static int _vgs_locked = 0;
 static int _vg_global_lock_held = 0;	/* Global lock held when cache wiped? */
 
@@ -455,7 +455,7 @@ int lvmcache_label_scan(struct cmd_conte
 		goto out;
 	}
 
-	if (_has_scanned && !full_scan) {
+	if (!_need_scan && !full_scan) {
 		r = _scan_invalid();
 		goto out;
 	}
@@ -470,7 +470,7 @@ int lvmcache_label_scan(struct cmd_conte
 
 	dev_iter_destroy(iter);
 
-	_has_scanned = 1;
+	_need_scan = 0;
 
 	/* Perform any format-specific scanning e.g. text files */
 	dm_list_iterate_items(fmt, &cmd->formats) {
@@ -1239,7 +1239,7 @@ void lvmcache_destroy(struct cmd_context
 	struct dm_hash_node *n;
 	log_verbose("Wiping internal VG cache");
 
-	_has_scanned = 0;
+	_need_scan = 1;
 
 	if (_vgid_hash) {
 		dm_hash_destroy(_vgid_hash);

[RFC PATCH 3/7] separate metadata parse and verification

[Takahiro Yasui]

This patch separates parse and verification process in _reav_pv function.
Instead of getting device data by accessing and checking devices, the
DEV_NEED_VERIFY flag is set to the device structures so that they will
be verified later.


Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
---
 lib/cache/lvmcache.c          |    5 +++--
 lib/device/dev-cache.c        |   12 ++++++++++++
 lib/device/dev-cache.h        |    1 +
 lib/device/device.h           |    2 ++
 lib/format_text/format-text.c |   37 ++++++++++++++++++++++++++++++++-----
 lib/format_text/format-text.h |    2 ++
 lib/format_text/import_vsn1.c |   40 ++++++++++++++++++++++++++++------------
 lib/label/label.c             |    9 +++++++++
 8 files changed, 89 insertions(+), 19 deletions(-)

Index: LVM2.02.46-cvs-20090324/lib/cache/lvmcache.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/cache/lvmcache.c
+++ LVM2.02.46-cvs-20090324/lib/cache/lvmcache.c
@@ -525,6 +525,8 @@ struct volume_group *lvmcache_get_vg(con
 		return_NULL;
 	}
 
+	verify_pv_status(fid, vg);
+
 	log_debug("Using cached %smetadata for VG %s.",
 		  vginfo->precommitted ? "pre-committed" : "", vginfo->vgname);
 
@@ -705,7 +707,6 @@ static int _drop_vginfo(struct lvmcache_
 	return 1;
 }
 
-/* Unused
 void lvmcache_del(struct lvmcache_info *info)
 {
 	if (info->dev->pvid[0] && _pvid_hash)
@@ -718,7 +719,7 @@ void lvmcache_del(struct lvmcache_info *
 	dm_free(info);
 
 	return;
-} */
+}
 
 static int _lvmcache_update_pvid(struct lvmcache_info *info, const char *pvid)
 {
Index: LVM2.02.46-cvs-20090324/lib/device/dev-cache.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/device/dev-cache.c
+++ LVM2.02.46-cvs-20090324/lib/device/dev-cache.c
@@ -779,3 +779,15 @@ const char *dev_name(const struct device
 	return (dev) ? dm_list_item(dev->aliases.n, struct str_list)->str :
 	    "unknown device";
 }
+
+int dev_is_valid(struct device *dev, struct dev_filter *f)
+{
+	if (dev->flags & DEV_NEED_VERIFY) {
+		dev->flags &= ~DEV_NEED_VERIFY;
+
+		if (!f->passes_filter(f, dev))
+			return 0;
+	}
+
+	return 1;
+}
Index: LVM2.02.46-cvs-20090324/lib/device/dev-cache.h
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/device/dev-cache.h
+++ LVM2.02.46-cvs-20090324/lib/device/dev-cache.h
@@ -51,5 +51,6 @@ struct dev_iter;
 struct dev_iter *dev_iter_create(struct dev_filter *f, int dev_scan);
 void dev_iter_destroy(struct dev_iter *iter);
 struct device *dev_iter_get(struct dev_iter *iter);
+int dev_is_valid(struct device *dev, struct dev_filter *f);
 
 #endif
Index: LVM2.02.46-cvs-20090324/lib/device/device.h
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/device/device.h
+++ LVM2.02.46-cvs-20090324/lib/device/device.h
@@ -28,6 +28,8 @@
 #define DEV_O_DIRECT		0x00000020	/* Use O_DIRECT */
 #define DEV_O_DIRECT_TESTED	0x00000040	/* DEV_O_DIRECT is reliable */
 
+#define DEV_NEED_VERIFY		0x10000000	/* Should be verified */
+
 /*
  * All devices in LVM will be represented by one of these.
  * pointer comparisons are valid.
Index: LVM2.02.46-cvs-20090324/lib/format_text/format-text.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/format_text/format-text.c
+++ LVM2.02.46-cvs-20090324/lib/format_text/format-text.c
@@ -439,6 +439,27 @@ static int _raw_holds_vgname(struct form
 	return r;
 }
 
+void verify_pv_status(struct format_instance *fid, struct volume_group *vg)
+{
+	struct pv_list *pvl;
+	char buffer[64] __attribute((aligned(8)));
+
+	dm_list_iterate_items(pvl, &vg->pvs) {
+		if (!dev_is_valid(pvl->pv->dev, vg->cmd->filter) ||
+		    !(pvl->pv->dev = device_from_pvid(fid->fmt->cmd,
+						      &pvl->pv->id))) {
+			if (!id_write_format(&pvl->pv->id, buffer,
+					     sizeof(buffer)))
+				log_error("Couldn't find device.");
+			else
+				log_error("Couldn't find device with uuid"
+					  " '%s'.", buffer);
+
+			pvl->pv->status |= MISSING_PV;
+		}
+	}
+}
+
 static struct volume_group *_vg_read_raw_area(struct format_instance *fid,
 					      const char *vgname,
 					      struct device_area *area,
@@ -487,6 +508,8 @@ static struct volume_group *_vg_read_raw
 	if (precommitted)
 		vg->status |= PRECOMMITTED;
 
+	verify_pv_status(fid, vg);
+
       out:
 	if (!dev_close(area->dev))
 		stack;
@@ -783,7 +806,8 @@ static int _vg_remove_raw(struct format_
 
 static struct volume_group *_vg_read_file_name(struct format_instance *fid,
 					       const char *vgname,
-					       const char *read_path)
+					       const char *read_path,
+					       int verify_pv)
 {
 	struct volume_group *vg;
 	time_t when;
@@ -805,6 +829,9 @@ static struct volume_group *_vg_read_fil
 	} else
 		log_debug("Read volume group %s from %s", vg->name, read_path);
 
+	if (verify_pv)
+		verify_pv_status(fid, vg);
+
 	return vg;
 }
 
@@ -814,7 +841,7 @@ static struct volume_group *_vg_read_fil
 {
 	struct text_context *tc = (struct text_context *) mda->metadata_locn;
 
-	return _vg_read_file_name(fid, vgname, tc->path_live);
+	return _vg_read_file_name(fid, vgname, tc->path_live, 1);
 }
 
 static struct volume_group *_vg_read_precommit_file(struct format_instance *fid,
@@ -824,10 +851,10 @@ static struct volume_group *_vg_read_pre
 	struct text_context *tc = (struct text_context *) mda->metadata_locn;
 	struct volume_group *vg;
 
-	if ((vg = _vg_read_file_name(fid, vgname, tc->path_edit)))
+	if ((vg = _vg_read_file_name(fid, vgname, tc->path_edit, 1)))
 		vg->status |= PRECOMMITTED;
 	else
-		vg = _vg_read_file_name(fid, vgname, tc->path_live);
+		vg = _vg_read_file_name(fid, vgname, tc->path_live, 1);
 
 	return vg;
 }
@@ -1023,7 +1050,7 @@ static int _scan_file(const struct forma
 				fid = _text_create_text_instance(fmt, NULL, NULL,
 							    NULL);
 				if ((vg = _vg_read_file_name(fid, vgname,
-							     path)))
+							     path, 1)))
 					/* FIXME Store creation host in vg */
 					lvmcache_update_vg(vg, 0);
 			}
Index: LVM2.02.46-cvs-20090324/lib/format_text/format-text.h
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/format_text/format-text.h
+++ LVM2.02.46-cvs-20090324/lib/format_text/format-text.h
@@ -47,6 +47,8 @@ struct format_type *create_text_format(s
 void *create_text_context(struct cmd_context *cmd, const char *path,
 			  const char *desc);
 
+void verify_pv_status(struct format_instance *fid, struct volume_group *vg);
+
 struct labeller *text_labeller_create(const struct format_type *fmt);
 
 int pvhdr_read(struct device *dev, char *buf);
Index: LVM2.02.46-cvs-20090324/lib/format_text/import_vsn1.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/format_text/import_vsn1.c
+++ LVM2.02.46-cvs-20090324/lib/format_text/import_vsn1.c
@@ -150,6 +150,32 @@ static int _read_flag_config(struct conf
 	return 1;
 }
 
+static int _read_device(struct cmd_context *cmd, struct device **dev,
+			struct config_node *cn,	const char *path)
+{
+	struct config_value *cv;
+
+	if (!(cn = find_config_node(cn, path))) {
+		log_error("Couldn't find device.");
+		return 0;
+	}
+
+	cv = cn->v;
+	if (!cv || cv->type != CFG_STRING || !cv->v.str) {
+		log_error("device must be a string.");
+		return 0;
+	}
+
+	/* dev_cache_get function causes disk access if partition
+	   information is not cached on memory */
+	if (!(*dev = dev_cache_get(cv->v.str, NULL)))
+		return 0;
+
+	(*dev)->flags |= DEV_NEED_VERIFY;
+
+	return 1;
+}
+
 static int _read_pv(struct format_instance *fid, struct dm_pool *mem,
 		    struct volume_group *vg, struct config_node *pvn,
 		    struct config_node *vgn __attribute((unused)),
@@ -183,18 +209,8 @@ static int _read_pv(struct format_instan
 		return 0;
 	}
 
-	/*
-	 * Convert the uuid into a device.
-	 */
-	if (!(pv->dev = device_from_pvid(fid->fmt->cmd, &pv->id))) {
-		char buffer[64] __attribute((aligned(8)));
-
-		if (!id_write_format(&pv->id, buffer, sizeof(buffer)))
-			log_error("Couldn't find device.");
-		else
-			log_error("Couldn't find device with uuid '%s'.",
-				  buffer);
-	}
+	if (!_read_device(fid->fmt->cmd, &pv->dev, pvn, "device"))
+		log_error("Couldn't get device for physical volume.");
 
 	if (!(pv->vg_name = dm_pool_strdup(mem, vg->name)))
 		return_0;
Index: LVM2.02.46-cvs-20090324/lib/label/label.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/label/label.c
+++ LVM2.02.46-cvs-20090324/lib/label/label.c
@@ -19,6 +19,8 @@
 #include "xlate.h"
 #include "lvmcache.h"
 #include "metadata.h"
+#include "toolcontext.h"
+#include "dev-cache.h"
 
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -283,6 +285,13 @@ int label_read(struct device *dev, struc
 		return r;
 	}
 
+	if ((info = info_from_pvid(dev->pvid, 0))) {
+		if (!dev_is_valid(info->dev, info->fmt->cmd->filter)) {
+			lvmcache_del(info);
+			goto out;
+		}
+	}
+
 	if (!(l = _find_labeller(dev, buf, &sector, scan_sector)))
 		goto out;
 

[RFC PATCH 4/7] support metadata cache feature

[Takahiro Yasui]

Metadata cache files are read from the specified directory, and their
information are registered into lvmcache. The CACHE_INVALID flag is
set to the caches so that they will be reloaded from actual devices
when they are really processed.

This prototype uses metadata backup files in the backup directory as
cache files. But the own cache directory will be used in the future
version.


Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
---
 lib/cache/lvmcache.c          |    5 +++
 lib/cache/lvmcache.h          |    2 +
 lib/commands/toolcontext.c    |    1 
 lib/commands/toolcontext.h    |    3 ++
 lib/format_text/archiver.c    |   50 +++++++++++++++++++++++++++++++++
 lib/format_text/archiver.h    |    5 +++
 lib/format_text/format-text.c |   63 ++++++++++++++++++++++++++++++++++++++++++
 lib/metadata/metadata.h       |    5 +++
 8 files changed, 134 insertions(+)

Index: LVM2.02.46-cvs-20090324/lib/cache/lvmcache.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/cache/lvmcache.c
+++ LVM2.02.46-cvs-20090324/lib/cache/lvmcache.c
@@ -1274,3 +1274,8 @@ void lvmcache_destroy(struct cmd_context
 	if (retain_orphans)
 		init_lvmcache_orphans(cmd);
 }
+
+void lvmcache_reset_need_scan(void)
+{
+	_need_scan = 0;
+}
Index: LVM2.02.46-cvs-20090324/lib/cache/lvmcache.h
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/cache/lvmcache.h
+++ LVM2.02.46-cvs-20090324/lib/cache/lvmcache.h
@@ -112,4 +112,6 @@ struct dm_list *lvmcache_get_pvids(struc
 struct volume_group *lvmcache_get_vg(const char *vgid, unsigned precommitted);
 void lvmcache_drop_metadata(const char *vgname);
 
+void lvmcache_reset_need_scan(void);
+
 #endif
Index: LVM2.02.46-cvs-20090324/lib/commands/toolcontext.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/commands/toolcontext.c
+++ LVM2.02.46-cvs-20090324/lib/commands/toolcontext.c
@@ -776,6 +776,7 @@ static int _init_formats(struct cmd_cont
 	dm_list_add(&cmd->formats, &fmt->list);
 
 	cmd->fmt_backup = fmt;
+	cmd->fmt_mcache = fmt;
 
 	format = find_config_tree_str(cmd, "global/format",
 				 DEFAULT_FORMAT);
Index: LVM2.02.46-cvs-20090324/lib/commands/toolcontext.h
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/commands/toolcontext.h
+++ LVM2.02.46-cvs-20090324/lib/commands/toolcontext.h
@@ -33,6 +33,7 @@ struct config_info {
 	int suffix;
 	int archive;		/* should we archive ? */
 	int backup;		/* should we backup ? */
+	int mcache;		/* should we enable metadata cache ? */
 	int read_ahead;		/* DM_READ_AHEAD_NONE or _AUTO */
 	int cache_vgmetadata;
 	const char *msg_prefix;
@@ -56,6 +57,7 @@ struct cmd_context {
 
 	const struct format_type *fmt;	/* Current format to use by default */
 	struct format_type *fmt_backup;	/* Format to use for backups */
+	struct format_type *fmt_mcache;	/* Format to use for metadata cache */
 
 	struct dm_list formats;	/* Available formats */
 	struct dm_list segtypes;	/* Available segment types */
@@ -82,6 +84,7 @@ struct cmd_context {
 
 	struct archive_params *archive_params;
 	struct backup_params *backup_params;
+	struct mcache_params *mcache_params;
 	const char *stripe_filler;
 
 	/* List of defined tags */
Index: LVM2.02.46-cvs-20090324/lib/format_text/archiver.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/format_text/archiver.c
+++ LVM2.02.46-cvs-20090324/lib/format_text/archiver.c
@@ -35,6 +35,11 @@ struct backup_params {
 	char *dir;
 };
 
+struct mcache_params {
+	int enabled;
+	char *dir;
+};
+
 int archive_init(struct cmd_context *cmd, const char *dir,
 		 unsigned int keep_days, unsigned int keep_min,
 		 int enabled)
@@ -423,3 +428,48 @@ void check_current_backup(struct volume_
 	archive(vg);
 	backup(vg);
 }
+
+int mcache_init(struct cmd_context *cmd, const char *dir,
+		int enabled)
+{
+	if (!(cmd->mcache_params = dm_pool_zalloc(cmd->libmem,
+					       sizeof(*cmd->mcache_params)))) {
+		log_error("mcache_params alloc failed");
+		return 0;
+	}
+
+	cmd->mcache_params->dir = NULL;
+	if (!*dir)
+		return 1;
+
+	if (!(cmd->mcache_params->dir = dm_strdup(dir))) {
+		log_error("Couldn't copy mcache directory name.");
+		return 0;
+	}
+	mcache_enable(cmd, enabled);
+
+	return 1;
+}
+
+void mcache_exit(struct cmd_context *cmd)
+{
+	if (cmd->mcache_params->dir)
+		dm_free(cmd->mcache_params->dir);
+	memset(cmd->mcache_params, 0, sizeof(*cmd->mcache_params));
+}
+
+void mcache_enable(struct cmd_context *cmd, int flag)
+{
+	cmd->mcache_params->enabled = flag;
+}
+
+void mcache_load(struct cmd_context *cmd)
+{
+	if (!cmd->mcache_params->enabled || !cmd->mcache_params->dir)
+		return;
+
+	if (cmd->fmt_mcache->ops->scan_mcache &&
+	    cmd->fmt_mcache->ops->scan_mcache(cmd->fmt,
+					      cmd->mcache_params->dir))
+		lvmcache_reset_need_scan();
+}
Index: LVM2.02.46-cvs-20090324/lib/format_text/archiver.h
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/format_text/archiver.h
+++ LVM2.02.46-cvs-20090324/lib/format_text/archiver.h
@@ -59,4 +59,9 @@ int backup_to_file(const char *file, con
 
 void check_current_backup(struct volume_group *vg);
 
+int mcache_init(struct cmd_context *cmd, const char *dir, int enabled);
+void mcache_exit(struct cmd_context *cmd);
+void mcache_enable(struct cmd_context *cmd, int flag);
+void mcache_load(struct cmd_context *cmd);
+
 #endif
Index: LVM2.02.46-cvs-20090324/lib/format_text/format-text.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/format_text/format-text.c
+++ LVM2.02.46-cvs-20090324/lib/format_text/format-text.c
@@ -1062,6 +1062,68 @@ static int _scan_file(const struct forma
 	return 1;
 }
 
+static int _text_scan_mcache(const struct format_type *fmt, const char *dir)
+{
+	struct dirent *dirent;
+	char *tmp;
+	DIR *d;
+	struct volume_group *vg;
+	struct format_instance *fid;
+	char path[PATH_MAX];
+	char *vgname;
+	int ret = 1;
+
+	if (!(d = opendir(dir))) {
+		log_sys_error("opendir", dir);
+		return 0;
+	}
+
+	while ((dirent = readdir(d))) {
+		if (!strcmp(dirent->d_name, ".") ||
+		    !strcmp(dirent->d_name, "..") ||
+		    ((tmp = strstr(dirent->d_name, ".tmp")) &&
+		     tmp == dirent->d_name + strlen(dirent->d_name) - 4))
+			continue;
+
+		vgname = dirent->d_name;
+		if (dm_snprintf(path, PATH_MAX, "%s/%s", dir, vgname) < 0) {
+			log_error("Name too long %s/%s", dir, vgname);
+			break;
+		}
+
+		/* FIXME stat file to see if it's changed */
+		fid = _text_create_text_instance(fmt, NULL, NULL, NULL);
+		if ((vg = _vg_read_file_name(fid, vgname, path, 0))) {
+			struct pv_list *pvl;
+			struct lvmcache_info *info;
+
+			dm_list_iterate_items(pvl, &vg->pvs) {
+				info = lvmcache_add(fmt->labeller,
+						    (char *)pvl->pv->id.uuid,
+						    pvl->pv->dev, vg->name,
+						    (char *)vg->id.uuid, 0);
+				if (!info) {
+					/* FIXME: remove all mcache here */
+					ret = 0;
+					goto out;
+				}
+
+				dm_list_init(&info->mdas);
+				dm_list_init(&info->das);
+
+				/* info is generated from metadata cache and
+				   it is need to be revalidated later */
+				info->status |= CACHE_INVALID;
+			}
+		}
+	}
+ out:
+	if (closedir(d))
+		log_sys_error("closedir", dir);
+
+	return ret;
+}
+
 const char *vgname_from_mda(const struct format_type *fmt,
 			    struct device_area *dev_area, struct id *vgid,
 			    uint32_t *vgstatus, char **creation_host,
@@ -1889,6 +1951,7 @@ void *create_text_context(struct cmd_con
 
 static struct format_handler _text_handler = {
 	.scan = _text_scan,
+	.scan_mcache = _text_scan_mcache,
 	.pv_read = _text_pv_read,
 	.pv_setup = _text_pv_setup,
 	.pv_write = _text_pv_write,
Index: LVM2.02.46-cvs-20090324/lib/metadata/metadata.h
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/metadata/metadata.h
+++ LVM2.02.46-cvs-20090324/lib/metadata/metadata.h
@@ -198,6 +198,11 @@ struct format_handler {
 	int (*scan) (const struct format_type * fmt);
 
 	/*
+	 * Load and setup metadata cache files
+	 */
+	int (*scan_mcache) (const struct format_type *fmt, const char *dir);
+
+	/*
 	 * Return PV with given path.
 	 */
 	int (*pv_read) (const struct format_type * fmt, const char *pv_name,

[RFC PATCH 5/7] add metadata cache interface

[Takahiro Yasui]

Metadata cache is loaded into lvmcache if the lvm configuration parameter,
"backup/metadata_cache" has a value of "1" and MCACHE_DISABLE flag is not
set in its lvm command context.


Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
---
 lib/commands/toolcontext.c |   14 ++++++++++++++
 lib/config/defaults.h      |    1 +
 tools/lvmcmdline.c         |    4 ++++
 tools/tools.h              |    3 ++-
 4 files changed, 21 insertions(+), 1 deletion(-)

Index: LVM2.02.46-cvs-20090324/lib/commands/toolcontext.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/commands/toolcontext.c
+++ LVM2.02.46-cvs-20090324/lib/commands/toolcontext.c
@@ -929,6 +929,7 @@ static int _init_backup(struct cmd_conte
 		log_warn("WARNING: Metadata changes will NOT be backed up");
 		backup_init(cmd, "", 0);
 		archive_init(cmd, "", 0, 0, 0);
+		mcache_init(cmd, "", 0);
 		return 1;
 	}
 
@@ -980,6 +981,19 @@ static int _init_backup(struct cmd_conte
 		return 0;
 	}
 
+	/* set up the metadata cache */
+	cmd->default_settings.mcache =
+		find_config_tree_bool(cmd, "backup/metadata_cache",
+				      DEFAULT_MCACHE_ENABLED);
+
+	/* TODO: Currently mcache uses the same directory as backup, but
+	 * mcache should be put in its own directory, ex) /etc/lvm/mcache.
+	 */
+	if (!mcache_init(cmd, dir, cmd->default_settings.mcache)) {
+		log_debug("mcache_init failed.");
+		return 0;
+	}
+
 	return 1;
 }
 
Index: LVM2.02.46-cvs-20090324/lib/config/defaults.h
===================================================================
--- LVM2.02.46-cvs-20090324.orig/lib/config/defaults.h
+++ LVM2.02.46-cvs-20090324/lib/config/defaults.h
@@ -18,6 +18,7 @@
 
 #define DEFAULT_ARCHIVE_ENABLED 1
 #define DEFAULT_BACKUP_ENABLED 1
+#define DEFAULT_MCACHE_ENABLED 0
 
 #define DEFAULT_ARCHIVE_SUBDIR "archive"
 #define DEFAULT_BACKUP_SUBDIR "backup"
Index: LVM2.02.46-cvs-20090324/tools/lvmcmdline.c
===================================================================
--- LVM2.02.46-cvs-20090324.orig/tools/lvmcmdline.c
+++ LVM2.02.46-cvs-20090324/tools/lvmcmdline.c
@@ -777,6 +777,7 @@ static int _get_settings(struct cmd_cont
 
 	cmd->current_settings.archive = arg_int_value(cmd, autobackup_ARG, cmd->current_settings.archive);
 	cmd->current_settings.backup = arg_int_value(cmd, autobackup_ARG, cmd->current_settings.backup);
+	cmd->current_settings.mcache &= cmd->command->flags & MCACHE_DISABLE ? 0 : 1;
 	cmd->current_settings.cache_vgmetadata = cmd->command->flags & CACHE_VGMETADATA ? 1 : 0;
 	cmd->partial_activation = 0;
 
@@ -892,6 +893,7 @@ static void _apply_settings(struct cmd_c
 
 	archive_enable(cmd, cmd->current_settings.archive);
 	backup_enable(cmd, cmd->current_settings.backup);
+	mcache_enable(cmd, cmd->current_settings.mcache);
 
 	set_activation(cmd->current_settings.activation);
 
@@ -1004,6 +1006,8 @@ int lvm_run_command(struct cmd_context *
 		goto out;
 	}
 
+	mcache_load(cmd);
+
 	ret = cmd->command->fn(cmd, argc, argv);
 
 	fin_locking();
Index: LVM2.02.46-cvs-20090324/tools/tools.h
===================================================================
--- LVM2.02.46-cvs-20090324.orig/tools/tools.h
+++ LVM2.02.46-cvs-20090324/tools/tools.h
@@ -116,7 +116,8 @@ struct arg {
 	void *ptr;
 };
 
-#define CACHE_VGMETADATA 0x00000001
+#define CACHE_VGMETADATA	0x00000001
+#define MCACHE_DISABLE		0x00000002
 
 /* a register of the lvm commands */
 struct command {

[RFC PATCH 6/7] individual lvm command settings

[Takahiro Yasui]

Several lvm commands should not work based on metadata cache data. They
need to scan real metadata on devices. lvm commands with MCACHE_DISABLE
flag do not use metadata cache.

Currently the metadata cache feature is disabled in the following commands.

  * scan commands: vgscan and lvscan
      pvscan destroys lvmcache before its procedure, and MCACHE_DISABLE
      flag is not needed.

  * physical volume commands: pvdisplay, pvs
      Metadata cache files contain physical volume data which belong to
      a volume group, and orphan physical volumes can not be handled.
      To support these volumes, a kind of orphan physical volume cache
      need to be introduced.

As a next step, I'm planning to set MCACHE_CLEANUP flag to vgscan command
to refresh all metadata cache files in the cache directory.


Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
---
 tools/commands.h |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Index: LVM2.02.46-cvs-20090324/tools/commands.h
===================================================================
--- LVM2.02.46-cvs-20090324.orig/tools/commands.h
+++ LVM2.02.46-cvs-20090324/tools/commands.h
@@ -390,7 +390,7 @@ xx(lvs,
 
 xx(lvscan,
    "List all logical volumes in all volume groups",
-   0,
+   MCACHE_DISABLE,
    "lvscan " "\n"
    "\t[-a|--all]\n"
    "\t[-b|--blockdevice] " "\n"
@@ -497,7 +497,7 @@ xx(pvdata,
 
 xx(pvdisplay,
    "Display various attributes of physical volume(s)",
-   0,
+   MCACHE_DISABLE,
    "pvdisplay\n"
    "\t[-c|--colon]\n"
    "\t[-d|--debug]\n"
@@ -571,7 +571,7 @@ xx(pvremove,
 
 xx(pvs,
    "Display information about physical volumes",
-   0,
+   MCACHE_DISABLE,
    "pvs" "\n"
    "\t[--aligned]\n"
    "\t[-a|--all]\n"
@@ -925,7 +925,7 @@ xx(vgs,
 
 xx(vgscan,
    "Search for all volume groups",
-   0,
+   MCACHE_DISABLE,
    "vgscan "
    "\t[-d|--debug]\n"
    "\t[-h|--help]\n"

[RFC PATCH 7/7] introduce metadata cache feature

[Takahiro Yasui]

Add backup/metadata_cache parameter to enable the metadata cache
feature. Another new parameter, metadata_cache_dir will be added
in the future version to indicate metadata cache directory.


Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
---
 doc/example.conf |    6 ++++++
 1 file changed, 6 insertions(+)

Index: LVM2.02.46-cvs-20090324/doc/example.conf
===================================================================
--- LVM2.02.46-cvs-20090324.orig/doc/example.conf
+++ LVM2.02.46-cvs-20090324/doc/example.conf
@@ -187,6 +187,12 @@ backup {
 
     # What is the minimum time you wish to keep an archive file for ?
     retain_days = 30
+
+    # Use metadata cache to get lvm structures in the system instead of
+    # scanning all devices every time. If any errors are detected, lvm
+    # commands fall back to not use metadata cache.
+    # 1 enables; 0 disables.
+    # metadata_cache = 0
 }
 
 # Settings for the running LVM2 in shell (readline) mode.