[lvm-devel] [PATCH 06/18] Allow raw_read_mda_header to be called from text_label.c.
Dave Wysochanski
dwysocha at redhat.com
Wed May 26 14:02:08 UTC 2010
We'd like to pass in mda_header to vgname_from_mda(). In order to
do this, we need to call raw_read_mda_header() from text_label.c,
_text_read(), which gets called from the label_read() path, and
peers into the metadata and update vginfo cache. We should check
the disable bit here, and if set, not peer into the vg metadata,
thus reducing the I/O to disk.
Signed-off-by: Dave Wysochanski <dwysocha at redhat.com>
---
lib/format_text/format-text.c | 33 +++++++++++++++++++--------------
lib/format_text/format-text.h | 1 +
lib/format_text/layout.h | 4 ++++
lib/format_text/text_label.c | 15 +++++++++++++--
4 files changed, 37 insertions(+), 16 deletions(-)
diff --git a/lib/format_text/format-text.c b/lib/format_text/format-text.c
index d5e7ff2..06b7b9b 100644
--- a/lib/format_text/format-text.c
+++ b/lib/format_text/format-text.c
@@ -37,9 +37,6 @@
#include <dirent.h>
#include <ctype.h>
-static struct mda_header *_raw_read_mda_header(const struct format_type *fmt,
- struct device_area *dev_area);
-
static struct format_instance *_text_create_text_instance(const struct format_type
*fmt, const char *vgname,
const char *vgid,
@@ -181,7 +178,7 @@ static int _pv_analyze_mda_raw (const struct format_type * fmt,
if (!dev_open(area->dev))
return_0;
- if (!(mdah = _raw_read_mda_header(fmt, area)))
+ if (!(mdah = raw_read_mda_header(fmt, area)))
goto_out;
rlocn = mdah->raw_locns;
@@ -308,8 +305,8 @@ static void _xlate_mdah(struct mda_header *mdah)
}
}
-static struct mda_header *_raw_read_mda_header(const struct format_type *fmt,
- struct device_area *dev_area)
+struct mda_header *raw_read_mda_header(const struct format_type *fmt,
+ struct device_area *dev_area)
{
struct mda_header *mdah;
@@ -453,7 +450,7 @@ static int _raw_holds_vgname(struct format_instance *fid,
if (!dev_open(dev_area->dev))
return_0;
- if (!(mdah = _raw_read_mda_header(fid->fmt, dev_area)))
+ if (!(mdah = raw_read_mda_header(fid->fmt, dev_area)))
return_0;
if (_find_vg_rlocn(dev_area, mdah, vgname, &noprecommit))
@@ -477,7 +474,7 @@ static struct volume_group *_vg_read_raw_area(struct format_instance *fid,
char *desc;
uint32_t wrap = 0;
- if (!(mdah = _raw_read_mda_header(fid->fmt, area)))
+ if (!(mdah = raw_read_mda_header(fid->fmt, area)))
goto_out;
if (!(rlocn = _find_vg_rlocn(area, mdah, vgname, &precommitted))) {
@@ -577,7 +574,7 @@ static int _vg_write_raw(struct format_instance *fid, struct volume_group *vg,
if (!dev_open(mdac->area.dev))
return_0;
- if (!(mdah = _raw_read_mda_header(fid->fmt, &mdac->area)))
+ if (!(mdah = raw_read_mda_header(fid->fmt, &mdac->area)))
goto_out;
rlocn = _find_vg_rlocn(&mdac->area, mdah,
@@ -683,7 +680,7 @@ static int _vg_commit_raw_rlocn(struct format_instance *fid,
if (!found)
return 1;
- if (!(mdah = _raw_read_mda_header(fid->fmt, &mdac->area)))
+ if (!(mdah = raw_read_mda_header(fid->fmt, &mdac->area)))
goto_out;
if (!(rlocn = _find_vg_rlocn(&mdac->area, mdah,
@@ -794,7 +791,7 @@ static int _vg_remove_raw(struct format_instance *fid, struct volume_group *vg,
if (!dev_open(mdac->area.dev))
return_0;
- if (!(mdah = _raw_read_mda_header(fid->fmt, &mdac->area)))
+ if (!(mdah = raw_read_mda_header(fid->fmt, &mdac->area)))
goto_out;
if (!(rlocn = _find_vg_rlocn(&mdac->area, mdah, vg->name, &noprecommit))) {
@@ -1077,12 +1074,12 @@ static int _scan_file(const struct format_type *fmt)
}
const char *vgname_from_mda(const struct format_type *fmt,
+ struct mda_header *mdah,
struct device_area *dev_area, struct id *vgid,
uint64_t *vgstatus, char **creation_host,
uint64_t *mda_free_sectors)
{
struct raw_locn *rlocn;
- struct mda_header *mdah;
uint32_t wrap = 0;
const char *vgname = NULL;
unsigned int len = 0;
@@ -1093,7 +1090,7 @@ const char *vgname_from_mda(const struct format_type *fmt,
if (mda_free_sectors)
*mda_free_sectors = ((dev_area->size - MDA_HEADER_SIZE) / 2) >> SECTOR_SHIFT;
- if (!(mdah = _raw_read_mda_header(fmt, dev_area)))
+ if (!mdah)
goto_out;
/* FIXME Cope with returning a list */
@@ -1182,6 +1179,7 @@ static int _scan_raw(const struct format_type *fmt)
struct format_instance fid;
struct id vgid;
uint64_t vgstatus;
+ struct mda_header *mdah;
raw_list = &((struct mda_lists *) fmt->private)->raws;
@@ -1195,13 +1193,20 @@ static int _scan_raw(const struct format_type *fmt)
continue;
}
- if ((vgname = vgname_from_mda(fmt, &rl->dev_area, &vgid, &vgstatus,
+ if (!(mdah = raw_read_mda_header(fmt, &rl->dev_area))) {
+ stack;
+ goto close_dev;
+ }
+
+ if ((vgname = vgname_from_mda(fmt, mdah,
+ &rl->dev_area, &vgid, &vgstatus,
NULL, NULL))) {
vg = _vg_read_raw_area(&fid, vgname, &rl->dev_area, 0);
if (vg)
lvmcache_update_vg(vg, 0);
}
+ close_dev:
if (!dev_close(rl->dev_area.dev))
stack;
}
diff --git a/lib/format_text/format-text.h b/lib/format_text/format-text.h
index 17997cc..9e1bdd7 100644
--- a/lib/format_text/format-text.h
+++ b/lib/format_text/format-text.h
@@ -61,6 +61,7 @@ int add_mda(const struct format_type *fmt, struct dm_pool *mem, struct dm_list *
void del_mdas(struct dm_list *mdas);
const char *vgname_from_mda(const struct format_type *fmt,
+ struct mda_header *mdah,
struct device_area *dev_area, struct id *vgid,
uint64_t *vgstatus, char **creation_host,
uint64_t *mda_free_sectors);
diff --git a/lib/format_text/layout.h b/lib/format_text/layout.h
index b7b2f2b..f23719a 100644
--- a/lib/format_text/layout.h
+++ b/lib/format_text/layout.h
@@ -76,6 +76,9 @@ struct mda_header {
struct raw_locn raw_locns[0]; /* NULL-terminated list */
} __attribute__ ((packed));
+struct mda_header *raw_read_mda_header(const struct format_type *fmt,
+ struct device_area *dev_area);
+
struct mda_lists {
struct dm_list dirs;
struct dm_list raws;
@@ -86,6 +89,7 @@ struct mda_lists {
struct mda_context {
struct device_area area;
uint64_t free_sectors;
+ struct mda_header *mdah; /* copy of the on-disk mdah */
struct raw_locn rlocn; /* Store inbetween write and commit */
};
diff --git a/lib/format_text/text_label.c b/lib/format_text/text_label.c
index 6f897e1..7083b89 100644
--- a/lib/format_text/text_label.c
+++ b/lib/format_text/text_label.c
@@ -262,6 +262,7 @@ static int _text_read(struct labeller *l, struct device *dev, void *buf,
const char *vgname;
uint64_t vgstatus;
char *creation_host;
+ struct mda_header *mdah;
pvhdr = (struct pv_header *) ((void *) buf + xlate32(lh->offset_xl));
@@ -303,13 +304,23 @@ static int _text_read(struct labeller *l, struct device *dev, void *buf,
stack;
continue;
}
- if ((vgname = vgname_from_mda(info->fmt, &mdac->area,
+ if (!(mdah = raw_read_mda_header(info->fmt, &mdac->area))) {
+ stack;
+ goto close_dev;
+ }
+
+ if ((vgname = vgname_from_mda(info->fmt, mdah,
+ &mdac->area,
&vgid, &vgstatus, &creation_host,
&mdac->free_sectors)) &&
!lvmcache_update_vgname_and_id(info, vgname,
(char *) &vgid, vgstatus,
- creation_host))
+ creation_host)) {
+ if (!dev_close(mdac->area.dev))
+ stack;
return_0;
+ }
+ close_dev:
if (!dev_close(mdac->area.dev))
stack;
}
--
1.6.0.6
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