When we open (actually blkdev_get) a partition we need to also open (get) the
whole device that holds the partition. The involves some limited recursion.
This patch tries to simplify some aspects of this.
As well as opening the whole device, we need to increment ->bd_part_count when
a partition is opened (this is used by rescan_partitions to avoid a rescan if
any partition is active, as that would be confusing).
The main change this patch makes is to move the inc/dec of bd_part_count into
blkdev_{get,put} for the whole rather than doing it in blkdev_{get,put} for
the partition.
More specifically, we introduce __blkdev_get and __blkdev_put which do exactly
what blkdev_{get,put} did, only with an extra "for_part" argument
(blkget_{get,put} then call the __ version with a '0' for the extra argument).
If for_part is 1, then the blkdev is being get(put) because a partition is
being opened(closed) for the first(last) time, and so bd_part_count should be
updated (on success). The particular advantage of pushing this function down
is that the bd_mutex lock (which is needed to update bd_part_count) is already
held at the lower level.
Note that this slightly changes the semantics of bd_part_count. Instead of
updating it whenever a partition is opened or released, it is now only updated
on the first open or last release. This is an adequate semantic as it is only
ever tested for "== 0".
Having introduced these functions we remove the current bd_part_count updates
from do_open (which is really the body of blkdev_get) and call
__blkdev_get(... 1). Similarly in blkget_put we remove the old bd_part_count
updates and call __blkget_put(..., 1). This call is moved to the end of
__blkdev_put to avoid nested locks of bd_mutex.
Finally the mutex_lock on whole->bd_mutex in do_open can be removed. It was
only really needed to protect bd_part_count, and that is now managed (and
protected) within the recursive call.
The observation that bd_part_count is central to the locking issues, and the
modifications to create __blkdev_put are from Peter Zijlstra.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The extra call to get_gendisk is not good. It causes a ->probe and possible
module load before it is really appropriate to do this.
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix the locking of signal->tty.
Use ->sighand->siglock to protect ->signal->tty; this lock is already used
by most other members of ->signal/->sighand. And unless we are 'current'
or the tasklist_lock is held we need ->siglock to access ->signal anyway.
(NOTE: sys_unshare() is broken wrt ->sighand locking rules)
Note that tty_mutex is held over tty destruction, so while holding
tty_mutex any tty pointer remains valid. Otherwise the lifetime of ttys
are governed by their open file handles. This leaves some holes for tty
access from signal->tty (or any other non file related tty access).
It solves the tty SLAB scribbles we were seeing.
(NOTE: the change from group_send_sig_info to __group_send_sig_info needs to
be examined by someone familiar with the security framework, I think
it is safe given the SEND_SIG_PRIV from other __group_send_sig_info
invocations)
[schwidefsky@de.ibm.com: 3270 fix]
[akpm@osdl.org: various post-viro fixes]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
utsname information is shown in the linux banner, which also is used for
/proc/version (which can have different utsname values inside a uts
namespaces). this patch makes the varying data arguments and changes the
string to a format string, using those arguments.
Signed-off-by: Herbert Poetzl <herbert@13thfloor.at>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
journal_stop() is not defined for ext4; change to ext4_journal_stop().
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Windows servers are pickier about NTLMv2 than Samba.
This enables more secure mounts to Windows (not just Samba)
ie when "sec=ntlmv2" is specified on the mount.
Signed-off-by: Steve French <sfrench@us.ibm.com>
* master.kernel.org:/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw: (73 commits)
[DLM] Clean up lowcomms
[GFS2] Change gfs2_fsync() to use write_inode_now()
[GFS2] Fix indent in recovery.c
[GFS2] Don't flush everything on fdatasync
[GFS2] Add a comment about reading the super block
[GFS2] Mount problem with the GFS2 code
[GFS2] Remove gfs2_check_acl()
[DLM] fix format warnings in rcom.c and recoverd.c
[GFS2] lock function parameter
[DLM] don't accept replies to old recovery messages
[DLM] fix size of STATUS_REPLY message
[GFS2] fs/gfs2/log.c:log_bmap() fix printk format warning
[DLM] fix add_requestqueue checking nodes list
[GFS2] Fix recursive locking in gfs2_getattr
[GFS2] Fix recursive locking in gfs2_permission
[GFS2] Reduce number of arguments to meta_io.c:getbuf()
[GFS2] Move gfs2_meta_syncfs() into log.c
[GFS2] Fix journal flush problem
[GFS2] mark_inode_dirty after write to stuffed file
[GFS2] Fix glock ordering on inode creation
...
Port fix to the off-by-one in find_next_usable_block's memscan from ext2 to
ext3; but it didn't cause a serious problem for ext3 because the additional
ext3_test_allocatable check rescued it from the error.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The reservations tree is an rb_tree not a list, so it's less confusing to use
rb_entry() than list_entry() - though they're both just container_of().
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ext3_new_blocks should reset the reservation window size to 0 when squeezing
the last blocks out of an almost full filesystem, so the retry doesn't skip
any groups with less than half that free, reporting ENOSPC too soon.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove the ki_retried member from struct kiocb. I think the idea was
bounced around a while back, but Arnaldo pointed out another reason that we
should dig it up when he pointed out that the last cacheline of struct
kiocb only contains 4 bytes. By removing the debugging member, we save
more than the 8 byte on 64 bit machines.
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Acked-by: Ken Chen <kenneth.w.chen@intel.com>
Acked-by: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
io_submit_one assigns ki_left = ki_nbytes = iocb->aio_nbytes, then calls
down to aio_setup_iocb, then to aio_setup_single_vector. In there,
ki_nbytes is reassigned to the same value it got two call stack above it.
There is no need to do so.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Acked-by: Zach Brown <zach.brown@oracle.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
NeilBrown
Peter Zijlstra
Oleg Nesterov
Herbert Poetzl
Randy Dunlap
Steve French
Trond Myklebust
Linus Torvalds
Avantika Mathur
Hugh Dickins
Johann Lombardi
Benjamin LaHaise
Chen, Kenneth W