Allow raw_read_mda_header to be called from text_label.c.

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.

In the process, move vgname_from_mda() to layout.h, since the fn
only gets called from format_text code, and we need the mda_header
definition from the private layout.h.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>

diff --git a/lib/format_text/format-text.c b/lib/format_text/format-text.c
index dc730fbe8478e18b402cc039d968ea1062a73746..bc8e98ab34315cf144e75e2528c07d3ff86f70d9 100644 (file)
--- 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;
 
@@ -459,7 +456,7 @@ 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))
@@ -483,7 +480,7 @@ 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))) {
@@ -583,7 +580,7 @@ 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,
@@ -689,7 +686,7 @@ 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,
@@ -800,7 +797,7 @@ 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))) {
@@ -1083,12 +1080,12 @@ 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;
@@ -1099,8 +1096,10 @@ 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) {
+               log_error(INTERNAL_ERROR "vgname_from_mda called with NULL pointer for mda_header");
                goto_out;
+       }
 
        /* FIXME Cope with returning a list */
        rlocn = mdah->raw_locns;
@@ -1188,6 +1187,7 @@ 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;
 
@@ -1201,13 +1201,20 @@ 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 9750ffad1a051d9093933a5e63aa19327bc260cd..eaf1e835c01159f7247e69e7ec0bb578ff0d016d 100644 (file)
--- a/lib/format_text/format-text.h
+++ b/lib/format_text/format-text.h
@@ -59,9 +59,4 @@ int add_mda(const struct format_type *fmt, struct dm_pool *mem, struct dm_list *
            struct device *dev, uint64_t start, uint64_t size);
 void del_mdas(struct dm_list *mdas);
 
-const char *vgname_from_mda(const struct format_type *fmt,
-                           struct device_area *dev_area, struct id *vgid,
-                           uint64_t *vgstatus, char **creation_host,
-                           uint64_t *mda_free_sectors);
-
 #endif

diff --git a/lib/format_text/layout.h b/lib/format_text/layout.h
index b7b2f2b680a9253dc7d1b905d3da8885ad63b4ea..5c90c151fa00b962bb494dccf1e780291a2d8e9a 100644 (file)
--- 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;
@@ -96,4 +99,11 @@ struct mda_context {
 #define LVM2_LABEL "LVM2 001"
 #define MDA_SIZE_MIN (8 * (unsigned) lvm_getpagesize())
 
+
+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);
+
 #endif

diff --git a/lib/format_text/text_label.c b/lib/format_text/text_label.c
index 6f897e1d0164be272c5bd95c5f207bdeba0c7dae..7083b89b58814917b21ee2f5d8c0bdc255441d92 100644 (file)
--- 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;
        }