Commit graph

8503 commits

Author SHA1 Message Date
Fabio Massimo Di Nitto
1a2781cfa5 [GFS2] Fix runtime issue with UP kernels
The issue is indeed UP vs SMP and it is totally random.

spin_is_locked() is a bad assertion because there is no correct answer on UP.
on UP spin_is_locked() has to return either one value or another, always.

This means that in my setup I am lucky enough to trigger the issue and your you
are lucky enough not to.

the patch in attachment removes the bogus calls to BUG_ON and according to David
(in CC and thanks for the long explanation on the problem) we can rely upon
things like lockdep to find problem that might be trying to catch.

Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:06 +00:00
David Teigland
00c134756c [GFS2] tidy up error message
Print error with log_error() to be consistent with others.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:04 +00:00
Fabio Massimo Di Nitto
0b7580c786 [GFS2] Check for installation of mount helpers for DLM mounts
The patch is a fix to abort mount if the mount.gfs* and possible
umount.* are missing from /sbin.

While we do what we can to guarantee that they are installed properly in
userland (CVS HEAD), we want to make sure that mount still aborts properly.

The only sign of missing helpers is that lock_dlm will receive no mount options
at all. According to David the problem does not exist for lock_nolock as the
helpers are not required.

The patch has been tested for both gfs and gfs2 and it works as expected. The
lack of mount.gfs* will generate an error that is propagated to mount:

oot@node1:~# mount -t  gfs2 /dev/nbd2 /mnt/
mount: wrong fs type, bad option, bad superblock on /dev/nbd2,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

[ 3513.303346] GFS2: fsid=: Trying to join cluster "lock_dlm", "gutsy:gfs2"
[ 3513.304546] DLM/GFS2/GFS ERROR: (u)mount helpers are not installed properly!
[ 3513.306290] GFS2: fsid=: can't mount proto=lock_dlm, table=gutsy:gfs2, hostdata=

You might want to notice that it will also avoid mount to hang or fail silently
or with strange errors that will require the cluster to reboot/restart before
you can actually mount the filesystem again.

Signed-off-by: Fabio M. Di Nitto <fabbione@ubuntu.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:08:01 +00:00
Steven Whitehouse
e35b921185 [GFS2] Don't periodically update the jindex
We only care about the content of the jindex in two cases,
one is when we mount the fs and the other is when we need
to recover another journal. In both cases we have to update
the jindex anyway, so there is no point in updating it
periodically between times, so this removes it to simplify
gfs2_logd.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:59 +00:00
Steven Whitehouse
ec69b18883 [GFS2] Move gfs2_logd into log.c
This means that we can mark gfs2_ail1_empty static and prepares
the way for further changes.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:56 +00:00
Steven Whitehouse
fd041f0b40 [GFS2] Use atomic_t for journal free blocks counter
This patch changes the counter which keeps track of the free
blocks in the journal to an atomic_t in preparation for the
following patch which will update the log reservation code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:54 +00:00
Steven Whitehouse
2bcd610d2f [GFS2] Don't add glocks to the journal
The only reason for adding glocks to the journal was to keep track
of which locks required a log flush prior to release. We add a
flag to the glock to allow this check to be made in a simpler way.

This reduces the size of a glock (by 12 bytes on i386, 24 on x86_64)
and means that we can avoid extra work during the journal flush.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:52 +00:00
David Teigland
8cbc434247 [GFS2] check kthread_should_stop when waiting
Use wait_event_interruptible() in the lock_dlm thread instead
of an open coded equivalent, and include a kthread_should_stop()
check in the wait test so we don't miss a kthread_stop().

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:49 +00:00
Bob Peterson
c7227e4642 [GFS2] Given device ID rather than s_id in "id" sysfs file
This patch changes the /sys/fs/gfs2/<s_id>/id file to give the device
id "major:minor" rather than the s_id.  That enables gfs2_tool to
match devices properly (by id, not name) when locating the tuning files.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:47 +00:00
Steven Whitehouse
e589665eb9 [GFS2] Remove flags no longer required
The HIF_MUTEX and HIF_PROMOTE flags were set on the glock holders
depending upon which of the two waiters lists they were going to
be queued upon. They were then tested when the holders were taken
off the lists to ensure that the right type of holder was being
dequeued.

Since we are already using separate lists, there doesn't seem a
lot of point having these flags as well, and since setting them
and testing them is in the fast path for locking and unlocking
glock, this patch removes them.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:44 +00:00
Steven Whitehouse
3042a2ccd6 [GFS2] Reorder writeback for glock sync
Previously we were doing (write data, wait for data, write metadata, wait
for metadata). After this patch we so (write metadata, write data, wait for
data, wait for metadata) which should be more efficient.

Also I noticed that the drop_bh and xmote_bh functions were almost
identical. In fact the only difference was a single test, and that
test is such that in the drop_bh case, it would always evaluate to
the correct result. As such we can use the xmote_bh functions in
all the places where we were using the drop_bh function and remove
the drop_bh functions.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:42 +00:00
Steven Whitehouse
52d4c74b08 [GFS2] Add sync_page to metadata address space operations
This set of address space operations was missing a sync_page
operation.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:40 +00:00
Steven Whitehouse
c2932e03db [GFS2] Remove "reclaim limit"
This call to reclaim glocks is not needed, and in particular we don't want it
in the fast path for locking glocks. The limit was entirely arbitrary anyway
and we can't expect users to adjust things like this, the remaining code will
do the right thing on its own.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:37 +00:00
Steven Whitehouse
60b0d08779 [GFS2] Remove unused variables
These haven't been used for some time, remove them.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:35 +00:00
Steven Whitehouse
47e83b5091 [GFS2] Use correct include file in ops_address.c
Something changed in the upstream kernel, and it needs this
one-liner to allow ops_address.c to build.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:32 +00:00
Steven Whitehouse
c41d4f09f1 [GFS2] Don't hold page lock when starting transaction
This is an addendum to the new AOPs work which moves the point
at which we take the page lock so that we don't get it until
the last possible moment. This resolves a conflict between
starting transactions and the page lock.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:30 +00:00
Steven Whitehouse
b8e7cbb65b [GFS2] Add writepages for GFS2 jdata
This patch resolves a lock ordering issue where we had been getting
a transaction lock in the wrong order with respect to the page lock.
By using writepages rather than just writepage, it is then possible
to start a transaction before locking the page, and thus matching the
locking order elsewhere in the code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:28 +00:00
Steven Whitehouse
9ff8ec32e5 [GFS2] Split gfs2_writepage into three cases
This patch splits gfs2_writepage into separate functions for each of
the three cases: writeback, ordered and journalled. As a result
it becomes a lot easier to see what each one is doing. The common
code is moved into gfs2_writepage_common.

This fixes a performance bug where we were doing more work than
strictly required in the ordered write case.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:25 +00:00
Steven Whitehouse
5561093e2c [GFS2] Introduce gfs2_set_aops()
Just like ext3 we now have three sets of address space operations
to cover the cases of writeback, ordered and journalled data
writes. This means that the individual operations can now become
less complicated as we are able to remove some of the tests for
file data mode from the code.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:23 +00:00
Steven Whitehouse
bf36a71316 [GFS2] Add gfs2_is_writeback()
This adds a function "gfs2_is_writeback()" along the lines of the
existing "gfs2_is_jdata()" in order to clean up the code and make
the various tests for the inode mode more obvious. It also fixes
the PageChecked() logic where we were resetting the flag too early
in the case of an error path.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:21 +00:00
Steven Whitehouse
e7e36f1435 [GFS2] Remove unused field in struct gfs2_inode
Removes a field that is not used.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:18 +00:00
Steven Whitehouse
f91a0d3e24 [GFS2] Remove useless i_cache from inodes
The i_cache was designed to keep references to the indirect blocks
used during block mapping so that they didn't have to be looked
up continually. The idea failed because there are too many places
where the i_cache needs to be freed, and this has in the past been
the cause of many bugs.

In addition there was no performance benefit being gained since the
disk blocks in question were cached anyway. So this patch removes
it in order to simplify the code to prepare for other changes which
would otherwise have had to add further support for this feature.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:16 +00:00
Steven Whitehouse
3cc3f710ce [GFS2] Use ->page_mkwrite() for mmap()
This cleans up the mmap() code path for GFS2 by implementing the
page_mkwrite function for GFS2. We are thus able to use the
generic filemap_fault function for our ->fault() implementation.

This now means that shared writable mappings will be much more
efficiently shared across the cluster if there is a reasonable
proportion of read activity (the greater proportion, the better).

As a side effect, it also reduces the size of the code, removes
special cases from readpage and readpages, and makes the code
path easier to follow.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:13 +00:00
Steven Whitehouse
51ff87bdd9 [GFS2] Clean up internal read function
As requested by Christoph, this patch cleans up GFS2's internal
read function so that it no longer uses the do_generic_mapping_read
function. This function is obsolete and GFS2 is the last user of it.

As a side effect the internal read code gets smaller and easier
to read and gfs2_readpage is split into two. One function has the locking
and the other function has the rest of the logic.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
2008-01-25 08:07:11 +00:00
Wendy Cheng
cc7e79b168 [GFS2] Handle multiple glock demote requests
Fix a race condition where multiple glock demote requests are sent to
a node back-to-back. This patch does a check inside handle_callback()
to see whether a demote request is in progress. If true, it sets a flag
to make sure run_queue() will loop again to handle the new request,
instead of erronously setting gl_demote_state to a different state.

Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2008-01-25 08:07:09 +00:00
Greg Kroah-Hartman
197b12d679 Kobject: convert fs/* from kobject_unregister() to kobject_put()
There is no need for kobject_unregister() anymore, thanks to Kay's
kobject cleanup changes, so replace all instances of it with
kobject_put().


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:40 -08:00
Greg Kroah-Hartman
f9cb074bff Kobject: rename kobject_init_ng() to kobject_init()
Now that the old kobject_init() function is gone, rename
kobject_init_ng() to kobject_init() to clean up the namespace.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:38 -08:00
Kay Sievers
edfaa7c365 Driver core: convert block from raw kobjects to core devices
This moves the block devices to /sys/class/block. It will create a
flat list of all block devices, with the disks and partitions in one
directory. For compatibility /sys/block is created and contains symlinks
to the disks.

  /sys/class/block
  |-- sda -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda
  |-- sda1 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda1
  |-- sda10 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda10
  |-- sda5 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda5
  |-- sda6 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda6
  |-- sda7 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda7
  |-- sda8 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda8
  |-- sda9 -> ../../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda/sda9
  `-- sr0 -> ../../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0

  /sys/block/
  |-- sda -> ../devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/block/sda
  `-- sr0 -> ../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0/block/sr0

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:36 -08:00
Greg Kroah-Hartman
a5815ddf26 Kobject: convert fs/char_dev.c to use kobject_init/add_ng()
This converts the code to use the new kobject functions, cleaning up the
logic in doing so.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:31 -08:00
Greg Kroah-Hartman
901195ed7f Kobject: change GFS2 to use kobject_init_and_add
Stop using kobject_register, as this way we can control the sending of
the uevent properly, after everything is properly initialized.

Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:26 -08:00
Greg Kroah-Hartman
6e90aa972d kobject: convert ecryptfs to use kobject_create
Using a kset for this trivial directory is an overkill.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:24 -08:00
Greg Kroah-Hartman
0ff21e4663 kobject: convert kernel_kset to be a kobject
kernel_kset does not need to be a kset, but a much simpler kobject now
that we have kobj_attributes.

We also rename kernel_kset to kernel_kobj to catch all users of this
symbol with a build error instead of an easy-to-ignore build warning.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:24 -08:00
Greg Kroah-Hartman
830d3cfb16 kset: convert block_subsys to use kset_create
Dynamically create the kset instead of declaring it statically.  We also
rename block_subsys to block_kset to catch all users of this symbol
with a build error instead of an easy-to-ignore build warning.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:23 -08:00
Greg Kroah-Hartman
c60b717879 kset: convert ocfs2 to use kset_create
Dynamically create the kset instead of declaring it statically.

Also use the new kobj_attribute which cleans up this file a _lot_.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:23 -08:00
Kay Sievers
000f2a4d8c Driver Core: kill subsys_attribute and default sysfs ops
Remove the no longer needed subsys_attributes, they are all converted to
the more sensical kobj_attributes.

There is no longer a magic fallback in sysfs attribute operations, all
kobjects which create simple attributes need explicitely a ktype
assigned, which tells the core what was intended here.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:22 -08:00
Greg Kroah-Hartman
af6370ea92 ecryptfs: remove version_str file from sysfs
This file violates the one-value-per-file sysfs rule.

If you all want it added back, please do something like a per-feature
file to show what is present and what isn't.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:18 -08:00
Kay Sievers
386f275f5d Driver Core: switch all dynamic ksets to kobj_sysfs_ops
Switch all dynamically created ksets, that export simple attributes,
to kobj_attribute from subsys_attribute. Struct subsys_attribute will
be removed.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:18 -08:00
Greg Kroah-Hartman
bd35b93d80 kset: convert kernel_subsys to use kset_create
Dynamically create the kset instead of declaring it statically.  We also
rename kernel_subsys to kernel_kset to catch all users of this symbol
with a build error instead of an easy-to-ignore build warning.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:14 -08:00
Greg Kroah-Hartman
d405936b32 kset: convert dlm to use kset_create
Dynamically create the kset instead of declaring it statically.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:14 -08:00
Greg Kroah-Hartman
136a27507f kset: convert gfs2 dlm to use kset_create
Dynamically create the kset instead of declaring it statically.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:14 -08:00
Greg Kroah-Hartman
9bec101a0c kset: convert gfs2 to use kset_create
Dynamically create the kset instead of declaring it statically.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:13 -08:00
Greg Kroah-Hartman
00d2666623 kobject: convert main fs kobject to use kobject_create
This also renames fs_subsys to fs_kobj to catch all current users with a
build error instead of a build warning which can easily be missed.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:13 -08:00
Greg Kroah-Hartman
917e865df7 kset: convert ecryptfs to use kset_create
Dynamically create the kset instead of declaring it statically.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:13 -08:00
Greg Kroah-Hartman
3794491d0c kobject: convert configfs to use kobject_create
We don't need a kset here, a simple kobject will do just fine, so
dynamically create the kobject and use it.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:11 -08:00
Greg Kroah-Hartman
191e186bd0 kobject: convert debugfs to use kobject_create
We don't need a kset here, a simple kobject will do just fine, so
dynamically create the kobject and use it.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:11 -08:00
Greg Kroah-Hartman
5c89e17e9c kobject: convert fuse to use kobject_create
We don't need a kset here, a simple kobject will do just fine, so
dynamically create the kobject and use it.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:11 -08:00
Greg Kroah-Hartman
4ff6abff83 kobject: get rid of kobject_add_dir
kobject_create_and_add is the same as kobject_add_dir, so drop
kobject_add_dir.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:11 -08:00
Greg Kroah-Hartman
3514faca19 kobject: remove struct kobj_type from struct kset
We don't need a "default" ktype for a kset.  We should set this
explicitly every time for each kset.  This change is needed so that we
can make ksets dynamic, and cleans up one of the odd, undocumented
assumption that the kset/kobject/ktype model has.

This patch is based on a lot of help from Kay Sievers.

Nasty bug in the block code was found by Dave Young
<hidave.darkstar@gmail.com>

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:10 -08:00
Jiri Slaby
d7b3788965 sysfs: remove SPIN_LOCK_UNLOCKED
SPIN_LOCK_UNLOCKED is deprecated, use DEFINE_SPINLOCK instead

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tejun Heo <teheo@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:08 -08:00
Kay Sievers
2f90a85180 sysfs: create optimal relative symlink targets
Instead of walking from the source down to the root of sysfs, and back
to the target, we stop at the first directory the source and the target
share.

This link:
  /devices/pci0000:00/0000:00:1d.7/usb1/1-0:1.0/ep_81

pointed to:
  ../../../../../devices/pci0000:00/0000:00:1d.0/usb2/2-0:1.0/usb_endpoint/usbdev2.1_ep81

now it just points to:
  usb_endpoint/usbdev1.1_ep81

Thanks to Denis Cheng for bringing this up, and sending the initial patch.

CC: Denis Cheng <crquan@gmail.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:08 -08:00