| Message ID | 1240837258-5440-1-git-send-email-kzak@redhat.com |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Mon, Apr 27, 2009 at 03:00:57PM +0200, Karel Zak wrote: > The libblkid (since v1.41.1) returns private device-mapper names (e.g. > /dev/dm-0). It's because the probe_one() function scans /dev before > /dev/mapper. Checked in, thanks. Debian-derived distributions don't create /dev/dm-X names, which is why I didn't notice this issue. However, because of this, I modified your patch to keep this chunk which you removed: > - /* Do a short-cut scan of /dev/mapper first */ > - if (!devname) > - blkid__scan_dir("/dev/mapper", devno, 0, &devname); For distributions that don't create /dev/dm-X devices, your check above won't find the device name, so after searching /dev, we need to do a short-cut scan of /dev/mapper before we do a full brute force search via blkid_devno_to_devname. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, May 02, 2009 at 10:05:28PM -0400, Theodore Tso wrote: > On Mon, Apr 27, 2009 at 03:00:57PM +0200, Karel Zak wrote: > > The libblkid (since v1.41.1) returns private device-mapper names (e.g. > > /dev/dm-0). It's because the probe_one() function scans /dev before > > /dev/mapper. > > Checked in, thanks. Debian-derived distributions don't create > /dev/dm-X names, which is why I didn't notice this issue. However, > because of this, I modified your patch to keep this chunk which you removed: You needn't this chunk. > > - /* Do a short-cut scan of /dev/mapper first */ > > - if (!devname) > > - blkid__scan_dir("/dev/mapper", devno, 0, &devname); > > For distributions that don't create /dev/dm-X devices, your check I guess that all distributions have "dm-X" names in /proc/partitions, it means my check if (!strncmp(ptname, "dm-", 3) && isdigit(ptname[3])) blkid__scan_dir("/dev/mapper", devno, 0, &devname); works everywhere and you needn't to check /dev before /dev/mapper for dm-X ptnames. > above won't find the device name, so after searching /dev, we need to > do a short-cut scan of /dev/mapper before we do a full brute force > search via blkid_devno_to_devname. Karel
diff --git a/lib/blkid/devname.c b/lib/blkid/devname.c index 8553e9f..59c0919 100644 --- a/lib/blkid/devname.c +++ b/lib/blkid/devname.c @@ -179,6 +179,15 @@ static void probe_one(blkid_cache cache, const char *ptname, if (dev && dev->bid_devno == devno) goto set_pri; + /* Try to translate private device-mapper dm-<N> names + * to standard /dev/mapper/<name>. + */ + if (!strncmp(ptname, "dm-", 3) && isdigit(ptname[3])) { + blkid__scan_dir("/dev/mapper", devno, 0, &devname); + if (devname) + goto get_dev; + } + /* * Take a quick look at /dev/ptname for the device number. We check * all of the likely device directories. If we don't find it, or if @@ -197,17 +206,16 @@ static void probe_one(blkid_cache cache, const char *ptname, if (stat(device, &st) == 0 && S_ISBLK(st.st_mode) && st.st_rdev == devno) { devname = blkid_strdup(device); - break; + goto get_dev; } } - /* Do a short-cut scan of /dev/mapper first */ - if (!devname) - blkid__scan_dir("/dev/mapper", devno, 0, &devname); if (!devname) { devname = blkid_devno_to_devname(devno); if (!devname) return; } + +get_dev: dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL); free(devname);
The libblkid (since v1.41.1) returns private device-mapper names (e.g. /dev/dm-0). It's because the probe_one() function scans /dev before /dev/mapper. brw-rw---- 1 root disk 253, 0 2009-04-27 13:41 /dev/dm-0 brw-rw---- 1 root disk 253, 0 2009-04-27 13:41 /dev/mapper/TestVolGroup-TestLogVolume Old version: # blkid -t LABEL="TEST-LABEL" -o device /dev/dm-0 Fixed version: # blkid -t LABEL="TEST-LABEL" -o device /dev/mapper/TestVolGroup-TestLogVolume Addresses-Red-Hat-Bug: #497259 Signed-off-by: Karel Zak <kzak@redhat.com> --- lib/blkid/devname.c | 16 ++++++++++++---- 1 files changed, 12 insertions(+), 4 deletions(-)