Commit Graph

21526 Commits

Author SHA1 Message Date
Josef Bacik
4e69b598f6 Btrfs: cleanup how we setup free space clusters
This patch makes the free space cluster refilling code a little easier to
understand, and fixes some things with the bitmap part of it.  Currently we
either want to refill a cluster with

1) All normal extent entries (those without bitmaps)
2) A bitmap entry with enough space

The current code has this ugly jump around logic that will first try and fill up
the cluster with extent entries and then if it can't do that it will try and
find a bitmap to use.  So instead split this out into two functions, one that
tries to find only normal entries, and one that tries to find bitmaps.

This also fixes a suboptimal thing we would do with bitmaps.  If we used a
bitmap we would just tell the cluster that we were pointing at a bitmap and it
would do the tree search in the block group for that entry every time we tried
to make an allocation.  Instead of doing that now we just add it to the clusters
group.

I tested this with my ENOSPC tests and xfstests and it survived.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-25 19:08:08 -04:00
Josef Bacik
32cb0840ce Btrfs: don't be as aggressive about using bitmaps
We have been creating bitmaps for small extents unconditionally forever.  This
was great when testing to make sure the bitmap stuff was working, but is
overkill normally.  So instead of always adding small chunks of free space to
bitmaps, only start doing it if we go past half of our extent threshold.  This
will keeps us from creating a bitmap for just one small free extent at the front
of the block group, and will make the allocator a little faster as a result.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-21 10:26:03 -04:00
Josef Bacik
d0a365e84a Btrfs: deal with min_bytes appropriately when looking for a cluster
We do all this fun stuff with min_bytes, but either don't use it in the case of
just normal extents, or use it completely wrong in the case of bitmaps.  So fix
this for both cases

1) In the extent case, stop looking for space with window_free >= min_bytes
instead of bytes + empty_size.

2) In the bitmap case, we were looking for streches of free space that was at
least min_bytes in size, which was not right at all.  So instead search for
stretches of free space that are at least bytes in size (this will make a
difference when we have > page size blocks) and then only search for min_bytes
amount of free space.

Thanks,

Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-21 10:25:56 -04:00
Josef Bacik
7d0d2e8e6b Btrfs: check free space in block group before searching for a cluster
The free space cluster stuff is heavy duty, so there is no sense in going
through the entire song and dance if there isn't enough space in the block group
to begin with.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-21 10:25:48 -04:00
Josef Bacik
22a94d44bd Btrfs: add checks to verify dir items are correct
We need to make sure the dir items we get are valid dir items.  So any time we
try and read one check it with verify_dir_item, which will do various sanity
checks to make sure it looks sane.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:41 -04:00
Josef Bacik
41415730a1 Btrfs: check return value of btrfs_search_slot properly
Doing an audit of where we use btrfs_search_slot only showed one place where we
don't check the return value of btrfs_search_slot properly.  Just fix
mark_extent_written to see if btrfs_search_slot failed and act accordingly.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:39 -04:00
Josef Bacik
a826d6dcb3 Btrfs: check items for correctness as we search
Currently if we have corrupted items things will blow up in spectacular ways.
So as we read in blocks and they are leaves, check the entire leaf to make sure
all of the items are correct and point to valid parts in the leaf for the item
data the are responsible for.  If the item is corrupt we will kick back EIO and
not read any of the copies since they are likely to not be correct either.  This
will catch generic corruptions, it will be up to the individual callers of
btrfs_search_slot to make sure their items are right.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:37 -04:00
Josef Bacik
850265335f Btrfs: return error if the range we want to map is bogus
Currently if we have corrupt metadata map_extent_buffer will complain about it,
but not return an error so the caller has no idea a problem was hit.  Fix this.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:35 -04:00
Josef Bacik
695a0d0da0 Btrfs: add a comment explaining what btrfs_cont_expand does
Everytime I have to deal with btrfs_cont_expand I stare at it for 20 minutes
trying to remember what exactly it does and why the hell we need it.  So add a
comment to save future-Josef some time.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:33 -04:00
Josef Bacik
930f028abe Btrfs: use mark_inode_dirty when expanding the file
Mark_inode_dirty will call btrfs_dirty_inode which will take care of updating
the inode.  This makes setsize a little cleaner since we don't have to start a
transaction and update the inode in there, we can just call mark_inode_dirty.
Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:32 -04:00
Josef Bacik
f0cd846e92 Btrfs: only add orphan items when truncating
We don't need an orphan item when expanding files, we just need them for
truncating them, so only add the orphan item in btrfs_truncate instead of in
btrfs_setsize.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:30 -04:00
Josef Bacik
ded5db9de7 Btrfs: make sure to remove the orphan item from the in-memory list
This fixes a problem where if truncate fails the inode will still be on the in
memory orphan list.  This is will make us complain when the inode gets destroyed
because it's still on the orphan list.  So if we fail just remove us from the in
memory list and carry on.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:28 -04:00
Josef Bacik
66b4ffd110 Btrfs: handle errors in btrfs_orphan_cleanup
If we cannot truncate an inode for some reason we will never delete the orphan
item associated with that inode, which means that we will loop forever in
btrfs_orphan_cleanup.  Instead of doing this just return error so we fail to
mount.  It sucks, but hey it's better than hanging.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:26 -04:00
Josef Bacik
3893e33b0b Btrfs: cleanup error handling in the truncate path
Now that we can handle having errors in the truncate path lets make sure we
return errors instead of doing BUG_ON() and such.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:24 -04:00
Josef Bacik
a41ad394a0 Btrfs: convert to the new truncate sequence
->truncate() is going away, instead all of the work needs to be done in
->setattr().  So this converts us over to do this.  It's fairly straightforward,
just get rid of our .truncate inode operation and call btrfs_truncate() directly
from btrfs_setsize.  This works out better for us since truncate can technically
return ENOSPC, and before we had no way of letting anybody know.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:22 -04:00
Josef Bacik
dc89e98244 Btrfs: use a slab for the free space entries
Since we alloc/free free space entries a whole lot, lets use a slab to keep
track of them.  This makes some of my tests slightly faster.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:20 -04:00
Josef Bacik
57a45ced94 Btrfs: change reserved_extents to an atomic_t
We track delayed allocation per inodes via 2 counters, one is
outstanding_extents and reserved_extents.  Outstanding_extents is already an
atomic_t, but reserved_extents is not and is protected by a spinlock.  So
convert this to an atomic_t and instead of using a spinlock, use atomic_cmpxchg
when releasing delalloc bytes.  This makes our inode 72 bytes smaller, and
reduces locking overhead (albiet it was minimal to begin with).  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:18 -04:00
Josef Bacik
4a64001f00 Btrfs: fix how we deal with the pages array in the write path
Really we don't need to memset the pages array at all, since we know how many
pages we're going to use in the array and pass that around.  So don't memset,
just trust we're not idiots and we pass num_pages around properly.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:16 -04:00
Josef Bacik
d0215f3e5e Btrfs: simplify our write path
Our aio_write function is huge and kind of hard to follow at times.  So this
patch fixes this by breaking out the buffered and direct write paths out into
seperate functions so it's a little clearer what's going on.  I've also fixed
some wrong typing that we had and added the ability to handle getting an error
back from btrfs_set_extent_delalloc.  Tested this with xfstests and everything
came out fine.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:15 -04:00
Josef Bacik
9f570b8d48 Btrfs: fix formatting in file.c
Sorry, but these were bugging me.  Just cleanup some of the formatting in
file.c.

Signed-off-by: Josef Bacik <josef@redhat.com>
2011-03-17 14:21:13 -04:00
Linus Torvalds
5f40d42094 Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFS: NFSROOT should default to "proto=udp"
  nfs4: remove duplicated #include
  NFSv4: nfs4_state_mark_reclaim_nograce() should be static
  NFSv4: Fix the setlk error handler
  NFSv4.1: Fix the handling of the SEQUENCE status bits
  NFSv4/4.1: Fix nfs4_schedule_state_recovery abuses
  NFSv4.1 reclaim complete must wait for completion
  NFSv4: remove duplicate clientid in struct nfs_client
  NFSv4.1: Retry CREATE_SESSION on NFS4ERR_DELAY
  sunrpc: Propagate errors from xs_bind() through xs_create_sock()
  (try3-resend) Fix nfs_compat_user_ino64 so it doesn't cause problems if bit 31 or 63 are set in fileid
  nfs: fix compilation warning
  nfs: add kmalloc return value check in decode_and_add_ds
  SUNRPC: Remove resource leak in svc_rdma_send_error()
  nfs: close NFSv4 COMMIT vs. CLOSE race
  SUNRPC: Close a race in __rpc_wait_for_completion_task()
2011-03-14 11:19:50 -07:00
Timo Warns
1eafbfeb7b Fix corrupted OSF partition table parsing
The kernel automatically evaluates partition tables of storage devices.
The code for evaluating OSF partitions contains a bug that leaks data
from kernel heap memory to userspace for certain corrupted OSF
partitions.

In more detail:

  for (i = 0 ; i < le16_to_cpu(label->d_npartitions); i++, partition++) {

iterates from 0 to d_npartitions - 1, where d_npartitions is read from
the partition table without validation and partition is a pointer to an
array of at most 8 d_partitions.

Add the proper and obvious validation.

Signed-off-by: Timo Warns <warns@pre-sense.de>
Cc: stable@kernel.org
[ Changed the patch trivially to not repeat the whole le16_to_cpu()
  thing, and to use an explicit constant for the magic value '8' ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-14 10:14:28 -07:00
Al Viro
c44ed965be compat breakage in preadv() and pwritev()
Fix for a dumb preadv()/pwritev() compat bug - unlike the native
variants, the compat_...  ones forget to check FMODE_P{READ,WRITE}, so
e.g.  on pipe the native preadv() will fail with -ESPIPE and compat one
will act as readv() and succeed.

Not critical, but it's a clear bug with trivial fix, so IMO it's OK for
-final.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-13 16:29:07 -07:00
Linus Torvalds
0e5b88cd99 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: break out of shrink_delalloc earlier
  btrfs: fix not enough reserved space
  btrfs: fix dip leak
  Btrfs: make sure not to return overlapping extents to fiemap
  Btrfs: deal with short returns from copy_from_user
  Btrfs: fix regressions in copy_from_user handling
2011-03-13 16:00:49 -07:00
Chris Mason
36e39c40b3 Btrfs: break out of shrink_delalloc earlier
Josef had changed shrink_delalloc to exit after three shrink
attempts, which wasn't quite enough because new writers could
race in and steal free space.

But it also fixed deadlocks and stalls as we tried to recover
delalloc reservations.  The code was tweaked to loop 1024
times, and would reset the counter any time a small amount
of progress was made.  This was too drastic, and with a
lot of writers we can end up stuck in shrink_delalloc forever.

The shrink_delalloc loop is fairly complex because the caller is looping
too, and the caller will go ahead and force a transaction commit to make
sure we reclaim space.

This reworks things to exit shrink_delalloc when we've forced some
writeback and the delalloc reservations have gone down.  This means
the writeback has not just started but has also finished at
least some of the metadata changes required to reclaim delalloc
space.

If we've got this wrong, we're returning ENOSPC too early, which
is a big improvement over the current behavior of hanging the machine.

Test 224 in xfstests hammers on this nicely, and with 1000 writers
trying to fill a 1GB drive we get our first ENOSPC at 93% full.  The
other writers are able to continue until we get 100%.

This is a worst case test for btrfs because the 1000 writers are doing
small IO, and the small FS size means we don't have a lot of room
for metadata chunks.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-12 07:08:42 -05:00
Chuck Lever
53d4737580 NFS: NFSROOT should default to "proto=udp"
There have been a number of recent reports that NFSROOT is no longer
working with default mount options, but fails only with certain NICs.

Brian Downing <bdowning@lavos.net> bisected to commit 56463e50 "NFS:
Use super.c for NFSROOT mount option parsing".  Among other things,
this commit changes the default mount options for NFSROOT to use TCP
instead of UDP as the underlying transport.

TCP seems less able to deal with NICs that are slow to initialize.
The system logs that have accompanied reports of problems all show
that NFSROOT attempts to establish a TCP connection before the NIC is
fully initialized, and thus the TCP connection attempt fails.

When a TCP connection attempt fails during a mount operation, the
NFS stack needs to fail the operation.  Usually user space knows how
and when to retry it.  The network layer does not report a distinct
error code for this particular failure mode.  Thus, there isn't a
clean way for the RPC client to see that it needs to retry in this
case, but not in others.

Because NFSROOT is used in some environments where it is not possible
to update the kernel command line to specify "udp", the proper thing
to do is change NFSROOT to use UDP by default, as it did before commit
56463e50.

To make it easier to see how to change default mount options for
NFSROOT and to distinguish default settings from mandatory settings,
I've adjusted a couple of areas to document the specifics.

root_nfs_cat() is also modified to deal with commas properly when
concatenating strings containing mount option lists.  This keeps
root_nfs_cat() call sites simpler, now that we may be concatenating
multiple mount option strings.

Tested-by: Brian Downing <bdowning@lavos.net>
Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@kernel.org> # 2.6.37
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:38:07 -05:00
Huang Weiyi
57df216bd8 nfs4: remove duplicated #include
Remove duplicated #include('s) in
  fs/nfs/nfs4proc.c

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:18:37 -05:00
Trond Myklebust
f9feab1e18 NFSv4: nfs4_state_mark_reclaim_nograce() should be static
There are no more external users of nfs4_state_mark_reclaim_nograce() or
nfs4_state_mark_reclaim_reboot(), so mark them as static.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:18:36 -05:00
Trond Myklebust
ecac799a5e NFSv4: Fix the setlk error handler
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:18:36 -05:00
Trond Myklebust
b4410c2f7f NFSv4.1: Fix the handling of the SEQUENCE status bits
We want SEQUENCE status bits to be handled by the state manager in order
to avoid threading issues.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:18:35 -05:00
Trond Myklebust
0400a6b0cb NFSv4/4.1: Fix nfs4_schedule_state_recovery abuses
nfs4_schedule_state_recovery() should only be used when we need to force
the state manager to check the lease. If we just want to start the
state manager in order to handle a state recovery situation, we should be
using nfs4_schedule_state_manager().

This patch fixes the abuses of nfs4_schedule_state_recovery() by replacing
its use with a set of helper functions that do the right thing.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11 15:18:22 -05:00
Andy Adamson
c34c32ea97 NFSv4.1 reclaim complete must wait for completion
Signed-off-by: Andy Adamson <andros@netapp.com>
[Trond: fix whitespace errors]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10 15:05:01 -05:00
Andy Adamson
114f64b5f2 NFSv4: remove duplicate clientid in struct nfs_client
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10 15:05:00 -05:00
Ricardo Labiaga
7d6d63d642 NFSv4.1: Retry CREATE_SESSION on NFS4ERR_DELAY
Fix bug where we currently retry the EXCHANGEID call again, eventhough
we already have a valid clientid.  Instead, delay and retry the CREATE_SESSION
call.

Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10 15:04:59 -05:00
Frank Filz
3fa0b4e201 (try3-resend) Fix nfs_compat_user_ino64 so it doesn't cause problems if bit 31 or 63 are set in fileid
The problem was use of an int32, which when converted to a uint64
is sign extended resulting in a fileid that doesn't fit in 32 bits
even though the intent of the function is to fit the fileid into
32 bits.

Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
[Trond: Added an include for compat.h]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10 15:04:58 -05:00
Jovi Zhang
43b7c3f051 nfs: fix compilation warning
this commit fix compilation warning as following:
linux-2.6/fs/nfs/nfs4proc.c:3265: warning: comparison of distinct pointer types lacks a cast

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10 15:04:56 -05:00
Stanislav Fomichev
b9f810570d nfs: add kmalloc return value check in decode_and_add_ds
add kmalloc return value check in decode_and_add_ds

Signed-off-by: Stanislav Fomichev <kernel@fomichev.me>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10 15:04:55 -05:00
Jeff Layton
d2224e7afb nfs: close NFSv4 COMMIT vs. CLOSE race
I've been adding in more artificial delays in the NFSv4 commit and close
codepaths to uncover races. The kernel I'm testing has the patch to
close the race in __rpc_wait_for_completion_task that's in Trond's
cthon2011 branch. The reproducer I've been using does this in a loop:

	mkdir("DIR");
	fd = open("DIR/FILE", O_WRONLY|O_CREAT|O_EXCL, 0644);
	write(fd, "abcdefg", 7);
	close(fd);
	unlink("DIR/FILE");
	rmdir("DIR");

The above reproducer shouldn't result in any silly-renaming. However,
when I add a "msleep(100)" just after the nfs_commit_clear_lock call in
nfs_commit_release, I can almost always force one to occur. If I can
force it to occur with that, then it can happen without that delay
given the right timing.

nfs_commit_inode waits for the NFS_INO_COMMIT bit to clear when called
with FLUSH_SYNC set. nfs_commit_rpcsetup on the other hand does not wait
for the task to complete before putting its reference to it, so the last
reference get put in rpc_release task and gets queued to a workqueue.

In this situation, the last open context reference may be put by the
COMMIT release instead of the close() syscall. The close() syscall
returns too quickly and the unlink runs while the d_count is still
high since the COMMIT release hasn't put its dentry reference yet.

Fix this by having rpc_commit_rpcsetup wait for the RPC call to complete
before putting the task reference when FLUSH_SYNC is set. With this, the
last reference is put by the process that's initiating the FLUSH_SYNC
commit and the race is closed.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10 15:04:53 -05:00
Trond Myklebust
bf294b41ce SUNRPC: Close a race in __rpc_wait_for_completion_task()
Although they run as rpciod background tasks, under normal operation
(i.e. no SIGKILL), functions like nfs_sillyrename(), nfs4_proc_unlck()
and nfs4_do_close() want to be fully synchronous. This means that when we
exit, we want all references to the rpc_task to be gone, and we want
any dentry references etc. held by that task to be released.

For this reason these functions call __rpc_wait_for_completion_task(),
followed by rpc_put_task() in the expectation that the latter will be
releasing the last reference to the rpc_task, and thus ensuring that the
callback_ops->rpc_release() has been called synchronously.

This patch fixes a race which exists due to the fact that
rpciod calls rpc_complete_task() (in order to wake up the callers of
__rpc_wait_for_completion_task()) and then subsequently calls
rpc_put_task() without ensuring that these two steps are done atomically.

In order to avoid adding new spin locks, the patch uses the existing
waitqueue spin lock to order the rpc_task reference count releases between
the waiting process and rpciod.
The common case where nobody is waiting for completion is optimised for by
checking if the RPC_TASK_ASYNC flag is cleared and/or if the rpc_task
reference count is 1: in those cases we drop trying to grab the spin lock,
and immediately free up the rpc_task.

Those few processes that need to put the rpc_task from inside an
asynchronous context and that do not care about ordering are given a new
helper: rpc_put_task_async().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-10 15:04:52 -05:00
Miao Xie
7e6b6465e6 btrfs: fix not enough reserved space
btrfs_link() will insert 3 items(inode ref, dir name item and dir index item)
into the b+ tree and update 2 items(its inode, and parent's inode) in the b+
tree. So we should reserve space for these 5 items, not 3 items.

Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-10 11:21:49 -05:00
Daniel J Blueman
b4966b7770 btrfs: fix dip leak
The btrfs DIO code leaks dip structs when dip->csums allocation
fails; bio->bi_end_io isn't set at the point where the free_ordered
branch is consequently taken, thus bio_endio doesn't call the function
which would free it in the normal case. Fix.

Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Acked-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-03-10 11:21:49 -05:00
J. Bruce Fields
d891eedbc3 fs/dcache: allow d_obtain_alias() to return unhashed dentries
Without this patch, inodes are not promptly freed on last close of an
unlinked file by an nfs client:

	client$ mount -tnfs4 server:/export/ /mnt/
	client$ tail -f /mnt/FOO
	...
	server$ df -i /export
	server$ rm /export/FOO
	(^C the tail -f)
	server$ df -i /export
	server$ echo 2 >/proc/sys/vm/drop_caches
	server$ df -i /export

the df's will show that the inode is not freed on the filesystem until
the last step, when it could have been freed after killing the client's
tail -f. On-disk data won't be deallocated either, leading to possible
spurious ENOSPC.

This occurs because when the client does the close, it arrives in a
compound with a putfh and a close, processed like:

	- putfh: look up the filehandle.  The only alias found for the
	  inode will be DCACHE_UNHASHED alias referenced by the filp
	  this, so it creates a new DCACHE_DISCONECTED dentry and
	  returns that instead.
	- close: closes the existing filp, which is destroyed
	  immediately by dput() since it's DCACHE_UNHASHED.
	- end of the compound: release the reference
	  to the current filehandle, and dput() the new
	  DCACHE_DISCONECTED dentry, which gets put on the
	  unused list instead of being destroyed immediately.

Nick Piggin suggested fixing this by allowing d_obtain_alias to return
the unhashed dentry that is referenced by the filp, instead of making it
create a new dentry.

Leave __d_find_alias() alone to avoid changing behavior of other
callers.

Also nfsd doesn't need all the checks of __d_find_alias(); any dentry,
hashed or unhashed, disconnected or not, should work.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-10 05:18:54 -05:00
Marco Stornelli
1ca551c6ca Check for immutable/append flag in fallocate path
In the fallocate path the kernel doesn't check for the immutable/append
flag. It's possible to have a race condition in this scenario: an
application open a file in read/write and it does something, meanwhile
root set the immutable flag on the file, the application at that point
can call fallocate with success. In addition, we don't allow to do any
unreserve operation on an append only file but only the reserve one.

Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-10 04:22:15 -05:00
Al Viro
9177ada99d fat: fix d_revalidate oopsen on NFS exports
can't blindly check nd->flags in ->d_revalidate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-10 03:45:49 -05:00
Al Viro
8ce84eeb5b jfs: fix d_revalidate oopsen on NFS exports
can't blindly check nd->flags in ->d_revalidate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-10 03:45:28 -05:00
Al Viro
4714e63731 ocfs2: fix d_revalidate oopsen on NFS exports
can't blindly check nd->flags in ->d_revalidate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-10 03:45:07 -05:00
Al Viro
53fe924161 gfs2: fix d_revalidate oopsen on NFS exports
can't blindly check nd->flags in ->d_revalidate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-10 03:44:48 -05:00
Al Viro
529c5f958f fuse: fix d_revalidate oopsen on NFS exports
can't blindly check nd->flags in ->d_revalidate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-10 03:44:31 -05:00
Al Viro
0eb980e317 ceph: fix d_revalidate oopsen on NFS exports
can't blindly check nd->flags in ->d_revalidate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-10 03:44:05 -05:00
Al Viro
c78f4cc5e7 reiserfs xattr ->d_revalidate() shouldn't care about RCU
... it returns an error unconditionally

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-10 03:42:01 -05:00