inotify is intended to correct the deficiencies of dnotify, particularly
its inability to scale and its terrible user interface:

        * dnotify requires the opening of one fd per each directory
          that you intend to watch. This quickly results in too many
          open files and pins removable media, preventing unmount.
        * dnotify is directory-based. You only learn about changes to
          directories. Sure, a change to a file in a directory affects
          the directory, but you are then forced to keep a cache of
          stat structures.
        * dnotify's interface to user-space is awful.  Signals?

inotify provides a more usable, simple, powerful solution to file change
notification:

        * inotify's interface is a system call that returns a fd, not SIGIO.
	  You get a single fd, which is select()-able.
        * inotify has an event that says "the filesystem that the item
          you were watching is on was unmounted."
        * inotify can watch directories or files.

Inotify is currently used by Beagle (a desktop search infrastructure),
Gamin (a FAM replacement), and other projects.

See Documentation/filesystems/inotify.txt.
Signed-off-by: NRobert Love <rml@novell.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This was a pure indentation change, using:

	scripts/Lindent fs/reiserfs/*.c include/linux/reiserfs_*.h

to make reiserfs match the regular Linux indentation style.  As Jeff
Mahoney <jeffm@suse.com> writes:

 The ReiserFS code is a mix of a number of different coding styles, sometimes
 different even from line-to-line. Since the code has been relatively stable
 for quite some time and there are few outstanding patches to be applied, it
 is time to reformat the code to conform to the Linux style standard outlined
 in Documentation/CodingStyle.

 This patch contains the result of running scripts/Lindent against
 fs/reiserfs/*.c and include/linux/reiserfs_*.h. There are places where the
 code can be made to look better, but I'd rather keep those patches separate
 so that there isn't a subtle by-hand hand accident in the middle of a huge
 patch. To be clear: This patch is reformatting *only*.

 A number of patches may follow that continue to make the code more consistent
 with the Linux coding style.

 Hans wasn't particularly enthusiastic about these patches, but said he
 wouldn't really oppose them either.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 indent(1) doesn't know how to handle the "do not compile" error. It results
 in the item_ops array declaration being indented a tab stop in when it should
 not be. This patch replaces it with a #error that describes why it's failing.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

While fixing an oops in the st driver in a dirty release path, I
encountered an oops in cdev_put for cdevs allocated using cdev_alloc.  If
cdev_del is called when the cdev kobject still has an open user, when the
last cdev_put is called, the cdev_put will call kobject_put, which will end
up ultimately releasing the cdev in cdev_dynamic_release.  Patch fixes the
oops by preventing cdev_put from accessing freed memory.
Signed-off-by: NBrian King <brking@us.ibm.com>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Restore old set of ext2 mount options when remounting of a filesystem
fails.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix a problem with ext3 mount option parsing.  When remount of a filesystem
fails, old options are now restored.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When a noninitial thread does exec, it becomes the new group leader.  If
there is a ITIMER_REAL timer running, it points at the old group leader and
when it fires it can follow a stale pointer.  The timer data needs to be
reset to point at the exec'ing thread that is becoming the group leader.
This has to synchronize with any concurrent firing of the timer to make
sure that it_real_fn can never run when the data points to a thread that
might have been reaped already.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Bug symptoms
~~~~~~~~~~~~
For the same inode VFS calls read_inode() twice and doesn't call
clear_inode() between the two read_inode() invocations.

Bug description
~~~~~~~~~~~~~~~
Suppose we have an inode which has zero reference count but is still in
the inode cache. Suppose kswapd invokes shrink_icache_memory() to free
some RAM. In prune_icache() inodes are removed from i_hash. prune_icache
() is then going to call clear_inode(), but drops the inode_lock
spinlock before this. If in this moment another task calls iget() for an
inode which was just removed from i_hash by prune_icache(), then iget()
invokes read_inode() for this inode, because it is *already removed*
from i_hash.

The end result is: we call iget(#N) then iput(#N); inode #N has zero
i_count now and is in the inode cache; kswapd starts. kswapd removes the
inode #N from i_hash ans is preempted; we call iget(#N) again;
read_inode() is invoked as the result; but we expect clear_inode()
before.

Fix
~~~~~~~
To fix the bug I remove inodes from i_hash later, when clear_inode() is
actually called. I remove them from i_hash under spinlock protection.
Since the i_state is set to I_FREEING, it is safe to do this. The others
will sleep waiting for the inode state change.

I also postpone removing inodes from i_sb_list. It is not compulsory to
do so but I do it for readability reasons. Inodes are added/removed to
the lists together everywhere in the code and there is no point to
change this rule. This is harmless because the only user of i_sb_list
which somehow may interfere with me (invalidate_list()) is excluded by
the iprune_sem mutex.

The same race is possible in invalidate_list() so I do the same for it.
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch fixes queer behavior in __wait_on_freeing_inode().

If I_LOCK was not set it called yield(), effectively busy waiting for the
removal of the inode from the hash.  This change was introduced within
"[PATCH] eliminate inode waitqueue hashtable" Changeset 1.1938.166.16 last
october by wli.

The solution is to restore the old behavior, of unconditionally waiting on
the waitqueue.  It doesn't matter if I_LOCK is not set initally, the task
will go to sleep, and wake up when wake_up_inode() is called from
generic_delete_inode() after removing the inode from the hash chain.

Comment is also updated to better reflect current behavior.

This condition is very hard to trigger normally (simultaneous clear_inode()
with iget()) so probably only heavy stress testing can reveal any change of
behavior.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NTodd Poynor <tpoynor@mvista.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

In case of a mount error locks might be uninitialized but
accessed by the resulting call to jffs2_kill_sb().
Signed-off-by: NArtem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We recently changed the method of collecting and sorting of
tmp_dnode objects to use a temporary RB-tree instead of a
temporary list. Rename function and update comments.
Signed-off-by: NArtem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NArtem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NArtem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

After discussion at the recent NFSv4 bake-a-thon, I realized that my
assumption that NFS4_FH_PERSISTENT required filehandles to persist was a
misreading of the spec.  This also fixes an interoperability problem with the
Solaris client.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We shouldn't be allowing, e.g., write locks on files not open for read.  To
enforce this, we add a pointer from the lock stateid back to the open stateid
it came from, so that the check will continue to be correct even after the
open is upgraded or downgraded.
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

As long as we're here, do some miscellaneous cleanup.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The handling of close_lru in preprocess_stateid_op was a source of some
confusion here recently.  Try to make the logic a little clearer, by renaming
find_openstateowner_id to make its purpose clearer and untangling some
unnecessarily complicated goto's.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

nfs4_preprocess_seqid_op is called by NFSv4 operations that imply an implicit
renewal of the client lease.
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

from RFC 3530:
"Share reservations are established by OPEN operations and by their
nature are mandatory in that when the OPEN denies READ or WRITE
operations, that denial results in such operations being rejected
with error NFS4ERR_LOCKED."

(Note that share_denied is really only a legal error for OPEN.)
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

An OPEN from the same client/open stateowner requires a stateid update because
of the share/deny access update.
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We're insisting that the lock sequence id field passed in the
open_to_lockowner struct always be zero.  This is probably thanks to the
sentence in rfc3530: "The first request issued for any given lock_owner is
issued with a sequence number of zero."

But there doesn't seem to be any problem with allowing initial sequence
numbers other than zero.  And currently this is causing lock reclaims from the
Linux client to fail.

In the spirit of "be liberal in what you accept, conservative in what you
send", we'll relax the check (and patch the Linux client as well).
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add some comments on the use of so_seqid, in an attempt to avoid some of the
confusion outlined in the previous patch....
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The sequence number we store in the sequence id is the last one we received
from the client.  So on the next operation we'll check that the client gives
us the next higher number.

We increment sequence id's at the last moment, in encode, so that we're sure
of knowing the right error return.  (The decision to increment the sequence id
depends on the exact error returned.)

However on the *first* use of a sequence number, if we set the sequence number
to the one received from the client and then let the increment happen on
encode, we'll be left with a sequence number one to high.

For that reason, ENCODE_SEQID_OP_TAIL only increments the sequence id on
*confirmed* stateowners.

This creates a problem for open reclaims, which are confirmed on first use.
Therefore the open reclaim code, as a special exception, *decrements* the
sequence id, cancelling out the undesired increment on encode.  But this
prevents the sequence id from ever being incremented in the case where
multiple reclaims are sent with the same openowner.  Yuch!

We could add another exception to the open reclaim code, decrementing the
sequence id only if this is the first use of the open owner.

But it's simpler by far to modify the meaning of the op_seqid field: instead
of representing the previous value sent by the client, we take op_seqid, after
encoding, to represent the *next* sequence id that we expect from the client.
This eliminates the need for special-case handling of the first use of a
stateowner.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Yeah, it's trivial, but this drives me up the wall....
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A misreading of the spec lead us to convert all errors on open and lock
reclaims to RECLAIM_BAD.  This causes problems--for example, a reboot within
the grace period could lead to reclaims with stale stateid's, and we'd like to
return STALE errors in those cases.

What rfc3530 actually says about RECLAIM_BAD: "The reclaim provided by the
client does not match any of the server's state consistency checks and is
bad." I'm assuming that "state consistency checks" refers to checks for
consistency with the state recorded to stable storage, and that the error
should be reserved for that case.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A GRACE or NOGRACE response to a lock request should also bump the sequence
id.  So we delay the handling of grace period errors till after we've found
the relevant owner.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The GRACE and NOGRACE errors should bump the sequence id on open.  So we delay
the handling of these errors until nfsd4_process_open2, at which point we've
set the open owner, so the encode routine will be able to bump the sequence
id.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We oops in list_for_each_entry(), because release_stateowner frees something
on the list we're traversing.
Signed-off-by: NAndy Adamson <andros@citi.umich.edu>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make sure we don't try to delete client recovery directories multiple times;
fixes some spurious error messages.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Oops, this lookup_one_len needs the i_sem.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We need to fsync the recovery directory after writing to it, but we weren't
doing this correctly.  (For example, we weren't taking the i_sem when calling
->fsync().)

Just reuse the existing nfsd fsync code instead.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We need to remove the recovery directory here too.  (This chunk just got lost
somehow in the process of commuting the reboot recovery patches past the other
patches.)
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch renames _mntput() to something a little more descriptive:
mntput_no_expire().
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch renames vfsmount->mnt_fslink to something a little more
descriptive: vfsmount->mnt_expire.
Signed-off-by: NMike Waychison <michael.waychison@sun.com>
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Dcookies shouldn't play with the internals of dentry and vfsmnt
refcounting.  It defeats grepping, and is prone to break if implementation
details change.

In addition the function doesn't even seem to be performance critical: it
calls kmem_cache_alloc().
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch sets ->mnt_namespace where it's actually added to the
namespace.

Previously mnt_namespace was set in do_kern_mount() even if the filesystem
was never added to any process's namespace (most kernel-internal
filesystems).

This discrepancy doesn't actually cause any problems, but it's cleaner if
mnt_namespace is NULL for these non exported filesystems.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch clears mnt_namespace in an expired mount.

If mnt_namespace is not cleared, it's possible to attach a new mount to the
already detached mount, because check_mnt() can return true.

The effect is a resource leak, since the resulting tree will never be
freed.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch fixes a bug noticed by Al Viro:

   However, we still have a problem here - just what would
   happen if vfsmount is detached while we were grabbing namespace
   semaphore?  Refcount alone is not useful here - we might be held by
   whoever had detached the vfsmount.  IOW, we should check that it's
   still attached (i.e. that mnt->mnt_parent != mnt).  If it's not -
   just leave it alone, do mntput() and let whoever holds it deal with
   the sucker.  No need to put it back on lists.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch splits the mark_mounts_for_expiry() function.  It's too complex and
too deeply nested, even without the bugfix in the following patch.

Otherwise code is completely the same.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>