Commit Graph

48450 Commits

Author SHA1 Message Date
Trond Myklebust
7eeea16797 pNFS/flexfiles: Fix a statistics gathering imbalance
When we replay a failed read, write or commit to the dataserver, we
need to ensure that we call ff_layout_read_prepare_v3(),
ff_layout_write_prepare_v3 or ff_layout_commit_prepare_v3() so that we
reset the statistics.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:40 -05:00
Trond Myklebust
b9fc773ef5 pNFS/flexfiles: Don't mark the entire layout as failed, when returning it
In pNFS/flexfiles, we want to return the layout without necessarily marking
it as having completely failed. We therefore move the call to
pnfs_layout_io_set_failed() out of pnfs_error_mark_layout_for_return(),
and then ensura that pNFS/files layout calls it separately.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:40 -05:00
Trond Myklebust
2e5b29f044 pNFS/flexfiles: Don't prevent flexfiles client from retrying LAYOUTGET
Fix a bug in which flexfiles clients are falling back to I/O through the
MDS even when the FF_FLAGS_NO_IO_THRU_MDS flag is set.

The flexfiles client will always report errors through the LAYOUTRETURN
and/or LAYOUTERROR mechanisms, so it should normally be safe for it
to retry the LAYOUTGET until it fails or succeeds.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:40 -05:00
Peng Tao
141b9b59ed pnfs/flexfiles: count io stat in rpc_count_stats callback
If client ever restarts IO due to some errors, we'll endup
mis-counting IO stats if we do the counting in .rpc_done
callback. Move it to .rpc_count_stats callback that is only
called when releasing RPC.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:39 -05:00
Peng Tao
c22eeb8697 pnfs/flexfiles: do not mark delay-like status as DS failure
We just need to delay and retry in these cases.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:39 -05:00
Peng Tao
7c1e6e58e2 NFS41: map NFS4ERR_LAYOUTUNAVAILABLE to ENODATA
Instead of mapping it to EIO that is a fatal error and
fails application. We'll go inband after getting
NFS4ERR_LAYOUTUNAVAILABLE.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:38 -05:00
Peng Tao
d6c843b96e nfs: only remove page from mapping if launder_page fails
Instead of dropping pages when write fails, only do it when
we get fatal failure in launder_page write back.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:38 -05:00
Peng Tao
0bcbf039f6 nfs: handle request add failure properly
When we fail to queue a read page to IO descriptor,
we need to clean it up otherwise it is hanging around
preventing nfs module from being removed.

When we fail to queue a write page to IO descriptor,
we need to clean it up and also save the failure status
to open context. Then at file close, we can try to write
pages back again and drop the page if it fails to writeback
in .launder_page, which will be done in the next patch.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:37 -05:00
Peng Tao
2bff228857 nfs: centralize pgio error cleanup
In case we fail during setting things up for read/write IO, set
pg_error in IO descriptor and do the cleanup in nfs_pageio_add_request,
where we clean up all pages that are still hanging around on the IO
descriptor.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:37 -05:00
Peng Tao
c18b96a1b8 nfs: clean up rest of reqs when failing to add one
If we fail to set up things before sending anything over wire,
we need to clean up the reqs that are still attached to the
IO descriptor.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:37 -05:00
Peng Tao
d600ad1f2b NFS41: pop some layoutget errors to application
For ERESTARTSYS/EIO/EROFS/ENOSPC/E2BIG in layoutget, we
should just bail out instead of hiding the error and
retrying inband IO.

Change all the call sites to pop the error all the way up.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:36 -05:00
Trond Myklebust
d0379a5d06 pNFS/flexfiles: Support server-supplied layoutstats sampling period
Some servers want to be able to control the frequency with which clients
report layoutstats, for instance, in order to monitor QoS for a particular
file or set of file. In order to support this, the flexfiles layout allows
the server to pass this info as a hint in the layout payload.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 14:32:36 -05:00
Trond Myklebust
494f74a26c NFS: Flush reclaim writes using FLUSH_COND_STABLE
If there are already writes queued up for commit, then don't flush
just this page even if it is a reclaim issue.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 13:34:59 -05:00
Trond Myklebust
b0ac1bd2bb NFS: Background flush should not be low priority
Background flush is needed in order to satisfy the global page limits.
Don't subvert by reducing the priority.
This should also address a write starvation issue that was reported by
Neil Brown.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 13:30:42 -05:00
Trond Myklebust
1a093ceb05 NFSv4.1/pnfs: Fixup an lo->plh_block_lgets imbalance in layoutreturn
Since commit 2d8ae84fbc, nothing is bumping lo->plh_block_lgets in the
layoutreturn path, so it should not be touched in nfs4_layoutreturn_release
either.

Fixes: 2d8ae84fbc ("NFSv4.1/pnfs: Remove redundant lo->plh_block_lgets...")
Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 13:23:36 -05:00
Trond Myklebust
762674f86d NFSv4: Don't perform cached access checks before we've OPENed the file
Donald Buczek reports that a nfs4 client incorrectly denies
execute access based on outdated file mode (missing 'x' bit).
After the mode on the server is 'fixed' (chmod +x) further execution
attempts continue to fail, because the nfs ACCESS call updates
the access parameter but not the mode parameter or the mode in
the inode.

The root cause is ultimately that the VFS is calling may_open()
before the NFS client has a chance to OPEN the file and hence revalidate
the access and attribute caches.

Al Viro suggests:
>>> Make nfs_permission() relax the checks when it sees MAY_OPEN, if you know
>>> that things will be caught by server anyway?
>>
>> That can work as long as we're guaranteed that everything that calls
>> inode_permission() with MAY_OPEN on a regular file will also follow up
>> with a vfs_open() or dentry_open() on success. Is this always the
>> case?
>
> 1) in do_tmpfile(), followed by do_dentry_open() (not reachable by NFS since
> it doesn't have ->tmpfile() instance anyway)
>
> 2) in atomic_open(), after the call of ->atomic_open() has succeeded.
>
> 3) in do_last(), followed on success by vfs_open()
>
> That's all.  All calls of inode_permission() that get MAY_OPEN come from
> may_open(), and there's no other callers of that puppy.

Reported-by: Donald Buczek <buczek@molgen.mpg.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=109771
Link: http://lkml.kernel.org/r/1451046656-26319-1-git-send-email-buczek@molgen.mpg.de
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 13:22:20 -05:00
Arnd Bergmann
eb57bcc271 orangefs: fix typo in ornagefs_inode_lock
Orangefs fails to build on 32-bit SMP configurations due to a simple
misspelling, this does the obvious fix.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 575e946125 ("Orangefs: change pvfs2 filenames to orangefs")
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2015-12-28 10:31:21 -05:00
Nicholas Mc Guire
dde58ca436 Orangefs: use kzalloc for kmalloc + memset 0
This is an API consolidation only. The use of kmalloc + memset to 0
should be equivalent to kzalloc in this case.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2015-12-28 10:30:51 -05:00
Andrew Elble
99ade3c71b nfs: machine credential support for additional operations
Allow LAYOUTRETURN and DELEGRETURN to use machine credentials if the
server supports it. Add request for OPEN_DOWNGRADE as the close path
also uses that.

Signed-off-by: Andrew Elble <aweits@rit.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 09:57:15 -05:00
Wei Tang
ed47675249 nfs: do not initialise statics to 0
This patch fixes the checkpatch.pl error to nfs4sysctl.c:

ERROR: do not initialise statics to 0

Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 09:57:15 -05:00
Trond Myklebust
f4848303ce pNFS: Modify pnfs_update_layout tracepoints to use layout stateid
Instead of displaying a layout segment pointer in these tracepoints,
let's use the layout stateid, now that Olga gave us a set of tools for
displaying them.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 09:57:14 -05:00
Trond Myklebust
f2dd436edb NFSv4: Fix unused variable warnings in nfs4_init_*_client_string()
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 09:57:14 -05:00
Jeff Layton
9a4bf31d05 nfs: add new tracepoint for pnfs_update_layout
pnfs_update_layout is really the "nexus" of layout handling. If it
returns NULL then we end up going through the MDS. This patch adds
some tracepoints to that function that allow us to determine the
cause when we end up going through the MDS unexpectedly.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 09:57:14 -05:00
Olga Kornievskaia
9759b0fb1d Adding tracepoint to cached open
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 09:57:14 -05:00
Olga Kornievskaia
48c9579a1a Adding stateid information to tracepoints
Operations to which stateid information is added:
close, delegreturn, open, read, setattr, layoutget, layoutcommit, test_stateid,
write, lock, locku, lockt

Format is "stateid=<seqid>:<crc32 hash stateid.other>", also "openstateid=",
"layoutstateid=", and "lockstateid=" for open_file, layoutget, set_lock
tracepoints.

New function is added to internal.h, nfs_stateid_hash(), to compute the hash

trace_nfs4_setattr() is moved from nfs4_do_setattr() to _nfs4_do_setattr()
to get access to stateid.

trace_nfs4_setattr and trace_nfs4_delegreturn are changed from INODE_EVENT
to new event type, INODE_STATEID_EVENT which is same as INODE_EVENT but adds
stateid information

for locking tracepoints, moved trace_nfs4_set_lock() into _nfs4_do_setlk()
to get access to stateid information, and removed trace_nfs4_lock_reclaim(),
trace_nfs4_lock_expired() as they call into _nfs4_do_setlk() and both were
previously same LOCK_EVENT type.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 09:57:14 -05:00
Trond Myklebust
95864c9154 NFS: Allow the combination pNFS and labeled NFS
Fix the nfs4_pnfs_open_bitmap so that it also allows for labeled NFS.

Signed-off-by: Trond Myklebust <trond,myklebust@primarydata.com>
2015-12-28 09:57:08 -05:00
Peng Tao
68d264cf02 NFS42: handle layoutstats stateid error
When server returns layoutstats stateid error, we should
invalidate client's layout so that next IO can trigger new
layoutget.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 09:57:08 -05:00
Andrew Elble
361cad3c89 nfs: Fix race in __update_open_stateid()
We've seen this in a packet capture - I've intermixed what I
think was going on. The fix here is to grab the so_lock sooner.

1964379 -> #1 open (for write) reply seqid=1
1964393 -> #2 open (for read) reply seqid=2

  __nfs4_close(), state->n_wronly--
  nfs4_state_set_mode_locked(), changes state->state = [R]
  state->flags is [RW]
  state->state is [R], state->n_wronly == 0, state->n_rdonly == 1

1964398 -> #3 open (for write) call -> because close is already running
1964399 -> downgrade (to read) call seqid=2 (close of #1)
1964402 -> #3 open (for write) reply seqid=3

 __update_open_stateid()
   nfs_set_open_stateid_locked(), changes state->flags
   state->flags is [RW]
   state->state is [R], state->n_wronly == 0, state->n_rdonly == 1
   new sequence number is exposed now via nfs4_stateid_copy()

   next step would be update_open_stateflags(), pending so_lock

1964403 -> downgrade reply seqid=2, fails with OLD_STATEID (close of #1)

   nfs4_close_prepare() gets so_lock and recalcs flags -> send close

1964405 -> downgrade (to read) call seqid=3 (close of #1 retry)

   __update_open_stateid() gets so_lock
 * update_open_stateflags() updates state->n_wronly.
   nfs4_state_set_mode_locked() updates state->state

   state->flags is [RW]
   state->state is [RW], state->n_wronly == 1, state->n_rdonly == 1

 * should have suppressed the preceding nfs4_close_prepare() from
   sending open_downgrade

1964406 -> write call
1964408 -> downgrade (to read) reply seqid=4 (close of #1 retry)

   nfs_clear_open_stateid_locked()
   state->flags is [R]
   state->state is [RW], state->n_wronly == 1, state->n_rdonly == 1

1964409 -> write reply (fails, openmode)

Signed-off-by: Andrew Elble <aweits@rit.edu>
Cc: stable@vger,kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 09:57:08 -05:00
Andrew Elble
52618df95d nfs: fix missing assignment in nfs4_sequence_done tracepoint
status_flags not set

Signed-off-by: Andrew Elble <aweits@rit.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-12-28 09:57:08 -05:00
Andreas Gruenbacher
f39814f60a gfs2: Invalid security labels of inodes when they go invalid
When gfs2 releases the glock of an inode, it must invalidate all
information cached for that inode, including the page cache and acls.
Use the new security_inode_invalidate_secctx hook to also invalidate
security labels in that case.  These items will be reread from disk
when needed after reacquiring the glock.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: cluster-devel@redhat.com
[PM: fixed spelling errors and description line lengths]
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-12-24 11:09:40 -05:00
Chris Mason
140e639f1a btrfs: fix warning on uninit variable in btrfs_finish_chunk_alloc
map->num_stripes really can't be zero, but just in case.

Signed-off-by: Chris Mason <clm@fb.com>
2015-12-23 13:30:51 -08:00
Chris Mason
f0f76413d3 Merge branch 'freespace-4.5' into for-linus-4.5 2015-12-23 13:29:09 -08:00
Chris Mason
a53fe25769 Merge branch 'for-chris-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.5 2015-12-23 13:28:35 -08:00
Chris Mason
bb9d687618 Merge branch 'dev/simplify-set-bit' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5
Signed-off-by: Chris Mason <clm@fb.com>
2015-12-23 13:17:42 -08:00
Chris Mason
13d5d15d63 Merge branch 'dev/gfp-flags' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5 2015-12-23 13:11:27 -08:00
Chris Mason
afa427cf9d Merge branch 'cleanup/misc-simplify' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5 2015-12-23 13:10:26 -08:00
Jan Kara
6c37157874 udf: Fix lost indirect extent block
When inode ends with empty indirect extent block and we extended that
file, udf_do_extend_file() ended up just overwriting pointer to it with
another extent and thus effectively leaking the block and also
corruptiong length of allocation descriptors.

Fix the problem by properly following into next indirect extent when it
is present.

Signed-off-by: Jan Kara <jack@suse.cz>
2015-12-23 18:05:03 +01:00
Jan Kara
fcea62babc udf: Factor out code for creating indirect extent
Factor out code for creating indirect extent from udf_add_aext(). It was
mostly duplicated in two places. Also remove some opencoded versions
of udf_write_aext().

Signed-off-by: Jan Kara <jack@suse.cz>
2015-12-23 18:04:52 +01:00
Al Viro
b25472f9b9 new helpers: no_seek_end_llseek{,_size}()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-23 10:41:31 -05:00
Scott Mayhew
0751ddf77b lockd: Register callbacks on the inetaddr_chain and inet6addr_chain
Register callbacks on inetaddr_chain and inet6addr_chain to trigger
cleanup of lockd transport sockets when an ip address is deleted.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-12-23 10:08:16 -05:00
Scott Mayhew
366849966f nfsd: Register callbacks on the inetaddr_chain and inet6addr_chain
Register callbacks on inetaddr_chain and inet6addr_chain to trigger
cleanup of nfsd transport sockets when an ip address is deleted.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-12-23 10:08:15 -05:00
J. Bruce Fields
d4f72cb7fa nfsd: don't base cl_cb_status on stale information
The rpc client we use to send callbacks may change occasionally.  (In
the 4.0 case, the client can use setclientid/setclientid_confirm to
update the callback parameters.  In the 4.1+ case, sessions and
connections can come and go.)

The update is done from the callback thread by nfsd4_process_cb_update,
which shuts down the old rpc client and then creates a new one.

The client shutdown kills any ongoing rpc calls.  There won't be any new
ones till the new one's created and the callback thread moves on.

When an rpc encounters a problem that may suggest callback rpc's
aren't working any longer, it normally sets NFSD4_CB_DOWN, so the server
can tell the client something's wrong.

But if the rpc notices CB_UPDATE is set, then the failure may just be a
normal result of shutting down the callback client.  Or it could just be
a coincidence, but in any case, it means we're runing with the old
about-to-be-discarded client, so the failure's not interesting.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-12-23 10:08:14 -05:00
Vegard Nossum
b0918d9f47 udf: limit the maximum number of indirect extents in a row
udf_next_aext() just follows extent pointers while extents are marked as
indirect. This can loop forever for corrupted filesystem. Limit number
the of indirect extents we are willing to follow in a row.

[JK: Updated changelog, limit, style]

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: stable@vger.kernel.org
Cc: Jan Kara <jack@suse.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jan Kara <jack@suse.cz>
2015-12-23 11:47:55 +01:00
Linus Torvalds
0bee6ec80b Merge tag 'nfsd-4.4-1' of git://linux-nfs.org/~bfields/linux
Pull nfsd fix from Bruce Fields:
 "Just one fix for a NFSv4 callback bug introduced in 4.4"

* tag 'nfsd-4.4-1' of git://linux-nfs.org/~bfields/linux:
  nfsd: don't hold ls_mutex across a layout recall
2015-12-22 15:52:32 -08:00
Jaegeuk Kim
7441ccef33 f2fs: use atomic variable for total_extent_tree
It would be better to use atomic variable for total_extent_tree.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-12-22 10:31:41 -08:00
Junxiao Bi
a93a998382 gfs2: fix flock panic issue
Commit 4f6563677a ("Move locks API users to locks_lock_inode_wait()")
moved flock/posix lock identify code to locks_lock_inode_wait(), but
missed to set fl_flags to FL_FLOCK which will cause kernel panic in
locks_lock_inode_wait().

Fixes: 4f6563677a ("Move locks API users to locks_lock_inode_wait()")
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2015-12-22 08:06:08 -06:00
Filipe Manana
e44081ef61 Btrfs: fix unprotected list operations at btrfs_write_dirty_block_groups
We call btrfs_write_dirty_block_groups() in the critical section of a
transaction's commit, when no other tasks can join the transaction and
add more block groups to the transaction's list of dirty block groups,
so we not taking the dirty block groups spinlock when checking for the
list's emptyness, grabbing its first element or deleting elements from
it.

However there's a special and rare case where we can have a concurrent
task adding elements to this list. We trigger writeback for space
caches before at btrfs_start_dirty_block_groups() and in past iterations
of the loop at btrfs_write_dirty_block_groups(), this means that when
the writeback finishes (which happens asynchronously) it creates a
task for the endio free space work queue that executes
btrfs_finish_ordered_io() - this function is able to join the transaction,
through btrfs_join_transaction_nolock(), and update the free space cache's
inode item in the root tree, which can result in COWing nodes of this tree
and therefore allocation of a new block group can happen, which gets added
to the transaction's list of dirty block groups while the transaction
commit task is operating on it concurrently.

So fix this by taking the dirty block groups spinlock before doing
operations on the dirty block groups list at
btrfs_write_dirty_block_groups().

Signed-off-by: Filipe Manana <fdmanana@suse.com>
2015-12-21 17:51:22 +00:00
Krzysztof Opasiak
d79d75b5c5 fs: configfs: Add unlocked version of configfs_depend_item()
This change is necessary for the SCSI target usb gadget composed with
configfs. In this case configfs will be used for two different purposes:
to compose a usb gadget and to configure the target part. If an instance
of tcm function is created in $CONFIGFS_ROOT/usb_gadget/<gadget>/functions
a tpg can be created in $CONFIGFS_ROOT/target/usb_gadget/<wwn>/, but after
a tpg is created the tcm function must not be removed until its
corresponding tpg is gone. While the configfs_depend/undepend_item() are
meant exactly for creating this kind of dependencies, they are not suitable
if the other kernel subsystem happens to be another subsystem in configfs,
so this patch adds unlocked versions meant for configfs callbacks.

Above description has been provided by:
Andrzej Pietrasiewicz <andrzej.p@samsung.com>

In configfs_depend_item() we have to consider two possible cases:

1) When we are called to depend another item in the same subsystem
   as caller
	In this case we should skip locking configfs root as we know
	that configfs is in valid state and our subsystem will not
	be unregistered during this call.

2) When we are called to depend item in different subsystem than
   our caller
	In this case we are also sure that configfs is in valid state
	but we have to lock root of configfs to avoid unregistration
	of target's subsystem. As it is other than caller's subsystem,
	there may be nothing what protects us against unregistration
	of that subsystem.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-20 18:04:03 -08:00
Krzysztof Opasiak
9a70adfff3 fs: configfs: Factor out configfs_find_subsys_dentry()
configfs_depend_item() is quite complicated and should
be split up into smaller functions. This also allow to
share this code with other functions.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-20 18:04:01 -08:00
Krzysztof Opasiak
9fb434e754 fs: configfs: Factor out configfs_do_depend_item()
configfs_depend_item() is quite complicated and should
be split up into smaller functions. This also allow to
share this code with other functions.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-20 18:03:59 -08:00