The mount options string is saved in sb->s_options. This patch removes
the redundant duplicating of the mount options. Also, since we are not
displaying anything special in show options, we replace v9fs_show_options
with generic_show_options for now.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Cast the error return value (ENOMEM) in v9fs_get_inode() to its
correct type using ERR_PTR.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Remove a redundant update of inode's i_uid and i_gid
after v9fs_get_inode() since the latter already sets up
a new inode and sets the proper uid and gid values.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
->get_sb can fail causing some badness. this patch fixes
* clear sb->fs_s_info in kill_sb.
* deactivate_locked_super() calls kill_sb (v9fs_kill_super) which closes the
destroys the client, clunks all its fids and closes the v9fs session.
Attempting to do it twice will cause an oops.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Add the delimiter ',' before the options when they are passed
and check if no option parameters are passed to prevent displaying
NULL in /proc/mounts.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Add missing p9stat_free in v9fs_inode_from_fid to avoid
any possible leaks.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Fix the comments -- mostly the improper and/or missing descriptions
of function parameters.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Add a missing iput when cleaning up if v9fs_get_inode
fails after returning a valid inode.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Check if v9fs_fid_add was successful or not based on its
return value.
Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
The inotify_add_watch man page specifies that inotify_add_watch() will
return a non-negative integer. However, historically the inotify
watches started at 1, not at 0.
Turns out that the inotifywait program provided by the inotify-tools
package doesn't properly handle a 0 watch descriptor. In 7e790dd5 we
changed from starting at 1 to starting at 0. This patch starts at 1,
just like in previous kernels, but also just like in previous kernels
it's possible for it to wrap back to 0. This preserves the kernel
functionality exactly like it was before the patch (neither method broke
the spec)
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In f44aebcc the tail drop logic of events with no file backing
(q_overflow and in_ignored) was reversed so IN_IGNORED events would
never be tail dropped. This now means that Q_OVERFLOW events are NOT
tail dropped. The fix is to not tail drop IN_IGNORED, but to tail drop
Q_OVERFLOW.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
inotify decides if private data it passed to get added to an event was
used by checking list_empty(). But it's possible that the event may
have been dequeued and the private event removed so it would look empty.
The fix is to use the return code from fsnotify_add_notify_event rather
than looking at the list.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The locking in xfs_iget_cache_hit currently has numerous problems:
- we clear the reclaim tag without i_flags_lock which protects
modifications to it
- we call inode_init_always which can sleep with pag_ici_lock
held (this is oss.sgi.com BZ #819)
- we acquire and drop i_flags_lock a lot and thus provide no
consistency between the various flags we set/clear under it
This patch fixes all that with a major revamp of the locking in
the function. The new version acquires i_flags_lock early and
only drops it once we need to call into inode_init_always or before
calling xfs_ilock.
This patch fixes a bug seen in the wild where we race modifying the
reclaim tag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
The triggered field of struct poll_wqueues introduced in commit
5f820f648c ("poll: allow f_op->poll to
sleep").
It was first set to 1 in pollwake() (now __pollwake() ), tested and
later set to 0 in poll_schedule_timeout(), but not initialized before.
As a result when the process needs to sleep, triggered was likely to be
non-zero even if pollwake() is not called before the first
poll_schedule_timeout(), meaning schedule_hrtimeout_range() would not be
called and an extra loop calling all ->poll() would be done.
This patch initialize triggered to 0 in poll_initwait() so the ->poll()
are not called twice before the process goes to sleep when it needs to.
Signed-off-by: Guillaume Knispel <gknispel@proformatique.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Although this file is only ever written and not read by
userspace, it seems that the utils are opening this
file O_RDWR, so we need to allow that.
Also fixes the whitespace which seemed to be broken.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: David Teigland <teigland@redhat.com>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (22 commits)
ocfs2: Fix possible deadlock when extending quota file
ocfs2: keep index within status_map[]
ocfs2: Initialize the cluster we're writing to in a non-sparse extend
ocfs2: Remove redundant BUG_ON in __dlm_queue_ast()
ocfs2/quota: Release lock for error in ocfs2_quota_write.
ocfs2: Define credit counts for quota operations
ocfs2: Remove syncjiff field from quota info
ocfs2: Fix initialization of blockcheck stats
ocfs2: Zero out padding of on disk dquot structure
ocfs2: Initialize blocks allocated to local quota file
ocfs2: Mark buffer uptodate before calling ocfs2_journal_access_dq()
ocfs2: Make global quota files blocksize aligned
ocfs2: Use ocfs2_rec_clusters in ocfs2_adjust_adjacent_records.
ocfs2: Fix deadlock on umount
ocfs2: Add extra credits and access the modified bh in update_edge_lengths.
ocfs2: Fail ocfs2_get_block() immediately when a block needs allocation
ocfs2: Fix error return in ocfs2_write_cluster()
ocfs2: Fix compilation warning for fs/ocfs2/xattr.c
ocfs2: Initialize count in aio_write before generic_write_checks
ocfs2: log the actual return value of ocfs2_file_aio_write()
...
* 'for-linus' of git://oss.sgi.com/xfs/xfs:
xfs: fix spin_is_locked assert on uni-processor builds
xfs: check for dinode realtime flag corruption
use XFS_CORRUPTION_ERROR in xfs_btree_check_sblock
xfs: switch to NOFS allocation under i_lock in xfs_attr_rmtval_get
xfs: switch to NOFS allocation under i_lock in xfs_readlink_bmap
xfs: switch to NOFS allocation under i_lock in xfs_attr_rmtval_set
xfs: switch to NOFS allocation under i_lock in xfs_buf_associate_memory
xfs: switch to NOFS allocation under i_lock in xfs_dir_cilookup_result
xfs: switch to NOFS allocation under i_lock in xfs_da_buf_make
xfs: switch to NOFS allocation under i_lock in xfs_da_state_alloc
xfs: switch to NOFS allocation under i_lock in xfs_getbmap
xfs: avoid memory allocation under m_peraglock in growfs code
We can't call nfs_readdata_release()/nfs_writedata_release() without
first initialising and referencing args.context. Doing so inside
nfs_direct_read_schedule_segment()/nfs_direct_write_schedule_segment()
causes an Oops.
We should rather be calling nfs_readdata_free()/nfs_writedata_free() in
those cases.
Looking at the O_DIRECT code, the "struct nfs_direct_req" is already
referencing the nfs_open_context for us. Since the readdata and writedata
structures carry a reference to that, we can simplify things by getting rid
of the extra nfs_open_context references, so that we can replace all
instances of nfs_readdata_release()/nfs_writedata_release().
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Without SMP or preemption spin_is_locked always returns false,
so we can't do an assert with it. Instead use assert_spin_locked,
which does the right thing on all builds.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reported-by: Johannes Engel <jcnengel@googlemail.com>
Tested-by: Johannes Engel <jcnengel@googlemail.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
Ramon tested XFS with a modified version of fsfuzzer and hit a NULL
pointer dereference in __xfs_get_blocks due to the RT device target
pointer being NULL.
To fix this reject inode with the realtime bit set on a a filesystem
without an RT subvolume during inode read.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Reported-by: Ramon de Carvalho Valle <ramon@risesecurity.org>
Tested-by: Ramon de Carvalho Valle <ramon@risesecurity.org>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
In Red Hat Bug 512552
- Can't write to XFS mount during raid5 resync
a user ran into corruption while resyncing a raid, and we failed
a consistency test, but didn't get much more info; it'd be nice
to call XFS_CORRUPTION_ERROR here so we can see the buffer
contents.
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
xfs_attr_rmtval_get is always called with i_lock held, but i_lock is taken
in reclaim context so all allocations under it must avoid recursions into
the filesystem.
Reported by the new reclaim context tracing in lockdep.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
xfs_readlink_bmap is called with i_lock held, but i_lock is taken in
reclaim context so all allocations under it must avoid recursions into
the filesystem.
Reported by the new reclaim context tracing in lockdep.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
xfs_attr_rmtval_set is always called with i_lock held, and i_lock is taken
in reclaim context so all allocations under it must avoid recursions into
the filesystem.
Reported by the new reclaim context tracing in lockdep.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
xfs_buf_associate_memory is used for setting up the spare buffer for the
log wrap case in xlog_sync which can happen under i_lock when called from
xfs_fsync. The i_lock mutex is taken in reclaim context so all allocations
under it must avoid recursions into the filesystem. There are a couple
more uses of xfs_buf_associate_memory in the log recovery code that are
also affected by this, but I'd rather keep the code simple than passing on
a gfp_mask argument. Longer term we should just stop requiring the memoery
allocation in xlog_sync by some smaller rework of the buffer layer.
Reported by the new reclaim context tracing in lockdep.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
xfs_dir_cilookup_result is always called with i_lock held, but i_lock is taken
in reclaim context so all allocations under it must avoid recursions into the
filesystem.
Reported by the new reclaim context tracing in lockdep.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
i_lock is taken in the reclaim context so all allocations under it
must avoid recursions into the filesystem.
Reported by the new reclaim context tracing in lockdep.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
xfs_da_state_alloc is always called with i_lock held, but i_lock is taken in
reclaim context so all allocations under it must avoid recursions into the
filesystem.
Reported by the new reclaim context tracing in lockdep.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
xfs_getbmap allocates memory with i_lock held, but i_lock is taken in
reclaim context so all allocations under it must avoid recursions into
the filesystem.
Reported by the new reclaim context tracing in lockdep.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
Allocate the memory for the larger m_perag array before taking the
per-AG lock as the per-AG lock can be taken under the i_lock which
can be taken from reclaim context.
Reported by the new reclaim context tracing in lockdep.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
In OCFS2, allocator locks rank above transaction start. Thus we
cannot extend quota file from inside a transaction less we could
deadlock.
We solve the problem by starting transaction not already in
ocfs2_acquire_dquot() but only in ocfs2_local_read_dquot() and
ocfs2_global_read_dquot() and we allocate blocks to quota files before starting
the transaction. In case we crash, quota files will just have a few blocks
more but that's no problem since we just use them next time we extend the
quota file.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
The problem is minor, but without ->cred_guard_mutex held we can race
with exec() and get the new ->mm but check old creds.
Now we do not need to re-check task->mm after ptrace_may_access(), it
can't be changed to the new mm under us.
Strictly speaking, this also fixes another very minor problem. Unless
security check fails or the task exits mm_for_maps() should never
return NULL, the caller should get either old or new ->mm.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
mm_for_maps() takes ->mmap_sem after security checks, this looks
strange and obfuscates the locking rules. Move this lock to its
single caller, m_start().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
It would be nice to kill __ptrace_may_access(). It requires task_lock(),
but this lock is only needed to read mm->flags in the middle.
Convert mm_for_maps() to use ptrace_may_access(), this also simplifies
the code a little bit.
Also, we do not need to take ->mmap_sem in advance. In fact I think
mm_for_maps() should not play with ->mmap_sem at all, the caller should
take this lock.
With or without this patch, without ->cred_guard_mutex held we can race
with exec() and get the new ->mm but check old creds.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Do not exceed array status_map[]
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
In a non-sparse extend, we correctly allocate (and zero) the clusters between
the old_i_size and pos, but we don't zero the portions of the cluster we're
writing to outside of pos<->len.
It handles clustersize > pagesize and blocksize < pagesize.
[Cleaned up by Joel Becker.]
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
invalidate_inode_pages2_range may return -EBUSY occasionally
which results Oops. This patch fixes the issue by moving
invalidate_inode_pages2_range into a loop and keeping calling
it until the return value is not -EBUSY.
The EBUSY return is temporary, and can happen when the btrfs release page
function is unable to release a page because the EXTENT_LOCK
bit is set.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
find_zlib_workspace returns an ERR_PTR value in an error case instead of NULL.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@match exists@
expression x, E;
statement S1, S2;
@@
x = find_zlib_workspace(...)
... when != x = E
(
* if (x == NULL || ...) S1 else S2
|
* if (x == NULL && ...) S1 else S2
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This takes care of the following entry from Dan's list:
fs/btrfs/inode.c +4788 btrfs_rename(36) warning: variable derefenced before check 'old_inode'
Reported-by: Dan Carpenter <error27@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Eugene Teo <eteo@redhat.com>
Cc: Julia Lawall <julia@diku.dk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* git://git.infradead.org/mtd-2.6:
jffs2: Fix return value from jffs2_do_readpage_nolock()
mtd: mtdblock: introduce mtdblks_lock
mtd: remove 'SBC8240 Wind River' Device Driver Code
mtd: OneNAND: OMAP2/3: free GPMC CS on module removal
mtd: OneNAND: fix incorrect bufferram offset
mtd: blkdevs: do not forget to get MTD devices
mtd: fix the conversion from dev to mtd_info
mtd: let include/linux/mtd/partitions.h stand on its own
The new credentials code broke load_flat_shared_library() as it now uses
an uninitialized cred pointer.
Reported-by: Bernd Schmidt <bernds_cb1@t-online.de>
Tested-by: Bernd Schmidt <bernds_cb1@t-online.de>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: David Howells <dhowells@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I suspect that mnt_want_write_file() may have wrong assumption. I think
mnt_want_write_file() is assuming it increments ->mnt_writers if
(file->f_mode & FMODE_WRITE). But, if it's special_file(), it is false?
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The FIEMAP_IOC_FIEMAP mapping ioctl was missing a 32-bit compat handler,
which means that 32-bit suerspace on 64-bit kernels cannot use this ioctl
command.
The structure is nicely aligned, padded, and sized, so it is just this
simple.
Tested w/ 32-bit ioctl tester (from Josef) on a 64-bit kernel on ext4.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Mark Lord <lkml@rtr.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josef Bacik <josef@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When freeing an inode that lost race getting added to the inode cache we
must not call into ->destroy_inode, because that would delete the inode
that won the race from the inode cache radix tree.
This patch uses splits a new xfs_inode_free helper out of xfs_ireclaim
and uses that plus __destroy_inode to make sure we really only free
the memory allocted for the inode that lost the race, and not mess with
the inode cache state.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reported-by: Alex Samad <alex@samad.com.au>
Reported-by: Andrew Randrianasulu <randrik@mail.ru>
Reported-by: Stephane <sharnois@max-t.com>
Reported-by: Tommy <tommy@news-service.com>
Reported-by: Miah Gregory <mace@darksilence.net>
Reported-by: Gabriel Barazer <gabriel@oxeva.fr>
Reported-by: Leandro Lucarella <llucax@gmail.com>
Reported-by: Daniel Burr <dburr@fami.com.au>
Reported-by: Nickolay <newmail@spaces.ru>
Reported-by: Michael Guntsche <mike@it-loops.com>
Reported-by: Dan Carley <dan.carley+linuxkern-bugs@gmail.com>
Reported-by: Michael Ole Olsen <gnu@gmx.net>
Reported-by: Michael Weissenbacher <mw@dermichi.com>
Reported-by: Martin Spott <Martin.Spott@mgras.net>
Reported-by: Christian Kujau <lists@nerdbynature.de>
Tested-by: Michael Guntsche <mike@it-loops.com>
Tested-by: Dan Carley <dan.carley+linuxkern-bugs@gmail.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
When we want to tear down an inode that lost the add to the cache race
in XFS we must not call into ->destroy_inode because that would delete
the inode that won the race from the inode cache radix tree.
This patch provides the __destroy_inode helper needed to fix this,
the actual fix will be in th next patch. As XFS was the only reason
destroy_inode was exported we shift the export to the new __destroy_inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Currently inode_init_always calls into ->destroy_inode if the additional
initialization fails. That's not only counter-intuitive because
inode_init_always did not allocate the inode structure, but in case of
XFS it's actively harmful as ->destroy_inode might delete the inode from
a radix-tree that has never been added. This in turn might end up
deleting the inode for the same inum that has been instanciated by
another process and cause lots of cause subtile problems.
Also in the case of re-initializing a reclaimable inode in XFS it would
free an inode we still want to keep alive.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
nilfs2: fix missing unlock in error path of nilfs_mdt_write_page
nilfs2: fix oops due to inconsistent state in page with discrete b-tree nodes
