blkid_devdirs was defined in blkidP.h and was never intended to be
used outside of the library. Since it no longer needs to be shared
across object files, rename it and turn it into a static variable.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit works by removing all calls from libdevmapper altogether,
and using the standard support for "normal" non-dm devices.
It depends on dm devices being placed in /dev/mapper (but the previous
code had this dependency anyway), and /proc/partitions containing dm
devices.
We don't actually rip out the libdevmapper code in this commit, but
just disable it via #undef HAVE_DEVMAPPER, just so it's easier to
review and understand the fundamental code changes. A subsequent
commit will remove the libdevmapper code, as well as unexport
the blkid_devdirs string array.
Thanks to Karel Zak for inspiring me to look at the dm code in blkid,
so I could realize how much it deserved to ripped out by its roots. :-)
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
On systems where is multi-path storage device is problem with duplicated
filesystems. The solution is select "the best" device. This is possible
by device-mapper library.
Short quotation from RH bugzilla:
With my patch, all dm devices remains in libblkid cache.
Only the top level dm devices are given high priority
and more appropriate node names (i.e. /dev/mapper/*) are used.
For example, if we have linear mapped dm device "ov1" over
dm device "disk1p3" which is multipath mapped to /dev/sdd3 and /dev/sdh3:
# dmsetup.static ls --tree
ov1 (253:5) <-- /dev/mapper/ov1 or /dev/dm-5
`-disk1p3 (253:4) <-- /dev/mapper/disk1p3 or /dev/dm-4
`-disk1 (253:0)
|- (8:112) <-- /dev/sdh
`- (8:48) <-- /dev/sdd
Original version of blkid will show:
# ./orig/blkid -t LABEL=mpdisk1p3 -l
/dev/sdd3: LABEL="mpdisk1p3" ... TYPE="ext3"
With my patch, blkid will show:
# ./deptree/blkid -t LABEL=mpdisk1p3 -l
/dev/mapper/ov1: LABEL="mpdisk1p3" ... TYPE="ext3"
In blkid cache, all devices are listed:
# ./orig/blkid -t LABEL=mpdisk1p3
/dev/sdd3: LABEL="mpdisk1p3" ... TYPE="ext3"
/dev/sdh3: LABEL="mpdisk1p3" ... TYPE="ext3"
/dev/dm-4: LABEL="mpdisk1p3" ... TYPE="ext3"
/dev/dm-5: LABEL="mpdisk1p3" ... TYPE="ext3"
# ./deptree/blkid -t LABEL=mpdisk1p3
/dev/mapper/ov1: LABEL="mpdisk1p3" ... TYPE="ext3"
/dev/sdd3: LABEL="mpdisk1p3" ... TYPE="ext3"
/dev/sdh3: LABEL="mpdisk1p3" ... TYPE="ext3"
/dev/dm-4: LABEL="mpdisk1p3" ... TYPE="ext3"
For more details see discussion on:
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=156324
Addresses Red Hat Bug: #156324
Signed-off-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
consistently when the blkid cache file is explicitly set
to /dev/null. (Addresses Debian Bug #292425)
Also expose blkid_verify() as a public function to the blkid library.
1) Only one tag with a particular name can be attached to a device
at a time. This significantly simplifies the library, and was needed
to allow the cache file to be re-read and changes integrated into the
in-core version of the data structure in a simpler fashion than earlier
versions of the library.
2) To accomodate this, the ext2/ext3 filesystems are now always tagged
as "ext2" type filesystems. Ext3 filesystems are tagged with a
SEC_TYPE tag with the value ext3.
3) The new blkid_read_cache() function checks the mod time of the
cache file, and if the file has been changed since the last time the
cache file was read into memory, it is re-read. This function is now
called before probing all of the devices in the system or searching
all devices in the cache for a specific tag value.
4) After probing all devices, blkid_flush_cache() is called to write
out the cache file. This assures that all of the hard work involved
in doing a blkid_probe_all() is saved to disk.
read.c (parse_tag): Do not return that blkid_tag when parsing
the blkid.tag file.
resolve.c (blkid_get_token, blkid_get_tagname_devname): Fold in
code from removed functions
tag.c (blkid_create_tag): Don't return the newly tag strcture
any more, as it's not needed.
(blkid_find_tag_cache, blkid_get_tag_cache,
blkid_token_to_tag, blkid_find_tv_tags): Remove these
functions, as they are either only used once or have
interfaces that should be deprecated.
(blkid_find_tag_dev, blkid_find_head_cache): Replace use
of blkid_tag with one or two const char * type/value
arguments.
(blkid_find_dev_with_tag): Fold in code from removed functions
probe.h, probe.c: Use a more sophisticated set of byte-swapping
routines which are more compact and efficient. Drop
calculation of bid_free, since it's unnecessary. Avoid
save.c (blkid_save_cache): Set the permissions on the blkid
cache file to 644.
Theodore Ts'o