libblkid: implement zone-aware probing

This patch makes libblkid zone-aware. It can probe the magic located at
some offset from the beginning of some specific zone of a device.

This patch introduces some new fields to struct blkid_idmag. They indicate
the magic location is placed related to a zone and the offset in the zone.

Also, this commit introduces `zone_size` to struct blkid_struct_probe. It
stores the size of zones of a device.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

diff --git a/libblkid/src/blkidP.h b/libblkid/src/blkidP.h
index a3fe6748a969eb6e6ff2f87433b741eaa2cb9043..e3a160aa97c0145b72d0ed9cf98c51af22eef003 100644 (file)
--- a/libblkid/src/blkidP.h
+++ b/libblkid/src/blkidP.h
@@ -150,6 +150,10 @@ struct blkid_idmag
        const char      *hoff;          /* hint which contains byte offset to kboff */
        long            kboff;          /* kilobyte offset of superblock */
        unsigned int    sboff;          /* byte offset within superblock */
+
+       int             is_zoned;       /* indicate magic location is calcluated based on zone position  */
+       long            zonenum;        /* zone number which has superblock */
+       long            kboff_inzone;   /* kilobyte offset of superblock in a zone */
 };
 
 /*
@@ -206,6 +210,7 @@ struct blkid_struct_probe
        dev_t                   disk_devno;     /* devno of the whole-disk or 0 */
        unsigned int            blkssz;         /* sector size (BLKSSZGET ioctl) */
        mode_t                  mode;           /* struct stat.sb_mode */
+       uint64_t                zone_size;      /* zone size (BLKGETZONESZ ioctl) */
 
        int                     flags;          /* private library flags */
        int                     prob_flags;     /* always zeroized by blkid_do_*() */

diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index a47a8720d4ac13b8efeaf0d9c1e7f480f6f9d9a2..219cceea0f947087d7df648056a45ec27050f29f 100644 (file)
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -94,6 +94,9 @@
 #ifdef HAVE_LINUX_CDROM_H
 #include <linux/cdrom.h>
 #endif
+#ifdef HAVE_LINUX_BLKZONED_H
+#include <linux/blkzoned.h>
+#endif
 #ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
@@ -177,6 +180,7 @@ blkid_probe blkid_clone_probe(blkid_probe parent)
        pr->disk_devno = parent->disk_devno;
        pr->blkssz = parent->blkssz;
        pr->flags = parent->flags;
+       pr->zone_size = parent->zone_size;
        pr->parent = parent;
 
        pr->flags &= ~BLKID_FL_PRIVATE_FD;
@@ -897,6 +901,7 @@ int blkid_probe_set_device(blkid_probe pr, int fd,
        pr->wipe_off = 0;
        pr->wipe_size = 0;
        pr->wipe_chain = NULL;
+       pr->zone_size = 0;
 
        if (fd < 0)
                return 1;
@@ -996,6 +1001,15 @@ int blkid_probe_set_device(blkid_probe pr, int fd,
 #endif
        free(dm_uuid);
 
+# ifdef HAVE_LINUX_BLKZONED_H
+       if (S_ISBLK(sb.st_mode)) {
+               uint32_t zone_size_sector;
+
+               if (!ioctl(pr->fd, BLKGETZONESZ, &zone_size_sector))
+                       pr->zone_size = zone_size_sector << 9;
+       }
+# endif
+
        DBG(LOWPROBE, ul_debug("ready for low-probing, offset=%"PRIu64", size=%"PRIu64"",
                                pr->off, pr->size));
        DBG(LOWPROBE, ul_debug("whole-disk: %s, regfile: %s",
@@ -1064,12 +1078,24 @@ int blkid_probe_get_idmag(blkid_probe pr, const struct blkid_idinfo *id,
        /* try to detect by magic string */
        while(mag && mag->magic) {
                unsigned char *buf;
+               uint64_t kboff;
                uint64_t hint_offset;
 
                if (!mag->hoff || blkid_probe_get_hint(pr, mag->hoff, &hint_offset) < 0)
                        hint_offset = 0;
 
-               off = hint_offset + ((mag->kboff + (mag->sboff >> 10)) << 10);
+               /* If the magic is for zoned device, skip non-zoned device */
+               if (mag->is_zoned && !pr->zone_size) {
+                       mag++;
+                       continue;
+               }
+
+               if (!mag->is_zoned)
+                       kboff = mag->kboff;
+               else
+                       kboff = ((mag->zonenum * pr->zone_size) >> 10) + mag->kboff_inzone;
+
+               off = hint_offset + ((kboff + (mag->sboff >> 10)) << 10);
                buf = blkid_probe_get_buffer(pr, off, 1024);
 
                if (!buf && errno)
@@ -1079,7 +1105,7 @@ int blkid_probe_get_idmag(blkid_probe pr, const struct blkid_idinfo *id,
                                buf + (mag->sboff & 0x3ff), mag->len)) {
 
                        DBG(LOWPROBE, ul_debug("\tmagic sboff=%u, kboff=%ld",
-                               mag->sboff, mag->kboff));
+                               mag->sboff, kboff));
                        if (offset)
                                *offset = off + (mag->sboff & 0x3ff);
                        if (res)