There can be an infinite loop if gss_create_upcall() is called without
the userspace program running.  To prevent this, we return -EACCES if
we notice that pipe_version hasn't changed (indicating that the pipe
has not been opened).
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

mark_inode_dirty_sync() grabs the same inode lock!

race conditions between holding the lock in pnfs_set_layoutcommit() and in
mark_inode_dirty_sync() can result in a second call to pnfs_layoutcommit_inode(), but
this will be a noop as NFS_INO_LAYOUTCOMMIT won't be set in the second call
Signed-off-by: NWeston Andros Adamson <dros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The inode was used in an earlier version of the code, but it isn't
used anymore.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We only need to call nfs_mark_request_dirty() once in nfs_writepage_setup().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In fs/nfs/super.c::nfs_fs_mount() we test for a NULL 'data':

...
 		if (data == NULL || mntfh == NULL)
 			goto out_free_fh;
...

and then further down in the function we test 'data' again:

...
 			nfs_fscache_get_super_cookie(
 				s, data ? data->fscache_uniq : NULL, NULL);
...

this second check is just dead code since there is no way 'data' could
possibly be NULL here.
We also rely on a non-NULL 'data' in more than one location between these
two tests, further proving the point that the second test is bogus.

This patch removes the dead code.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

nfs_scan_commit() is called with the inode->i_lock held, but it then
calls __mark_inode_dirty() while still holding the lock. This causes
a deadlock.

Push the inode->i_lock into nfs_scan_commit() so it can protect only
the parts of the code it needs to and can be dropped before the call
to __mark_inode_dirty() to avoid the deadlock.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Tested-by: NWill Simoneau <simoneau@ele.uri.edu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 93f1c20b.

It turns out that libmount misparses it because it adds a '-' character
in the uuid string, which libmount then incorrectly confuses with the
separator string (" - ") at the end of all the optional arguments.

Upstream libmount (in the util-linux tree) has been fixed, but until
that fix actually percolates up to users, we'd better not expose this
change in the kernel.

Let's revisit this later (possibly by exposing the UUID without any '-'
characters in it, avoiding the user-space bug).
Reported-by: NDave Jones <davej@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Karel Zak <kzak@redhat.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is more or less the same patch as before, but with some merge
conflicts fixed up.

If a process has a dirty page mapped into its page tables, then it has
the ability to change it while the client is trying to write the data
out to the server. If that happens after the signature has been
calculated then that signature will then be wrong, and the server will
likely reset the TCP connection.

This patch adds a page_mkwrite handler for CIFS that simply takes the
page lock. Because the page lock is held over the life of writepage and
writepages, this prevents the page from becoming writeable until
the write call has completed.

With this, we can also remove the "sign_zero_copy" module option and
always inline the pages when writing.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Warn once if default security (ntlm) requested. We will
update the default to the stronger security mechanism
(ntlmv2) in 2.6.41.  Kerberos is also stronger than
ntlm, but more servers support ntlmv2 and ntlmv2
does not require an upcall, so ntlmv2 is a better
default.
Reviewed-by: NJeff Layton <jlayton@redhat.com>
CC: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: NShirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

When the TCP_Server_Info is first allocated and connected, tcpStatus ==
CifsGood means that the NEGOTIATE_PROTOCOL request has completed and the
socket is ready for other calls. cifs_reconnect however sets tcpStatus
to CifsGood as soon as the socket is reconnected and the optional
RFC1001 session setup is done. We have no clear way to tell the
difference between these two states, and we need to know this in order
to know whether we can send an echo or not.

Resolve this by adding a new statusEnum value -- CifsNeedNegotiate. When
the socket has been connected but has not yet had a NEGOTIATE_PROTOCOL
request done, set it to this value. Once the NEGOTIATE is done,
cifs_negotiate_protocol will set tcpStatus to CifsGood.

This also fixes and cleans the logic in cifs_reconnect and
cifs_reconnect_tcon. The old code checked for specific states when what
it really wants to know is whether the state has actually changed from
CifsNeedReconnect.
Reported-and-Tested-by: NJG <jg@cms.ac>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

While testing my patchset to fix asynchronous writes, I hit a bunch
of signature problems when testing with signing on. The problem seems
to be that signature checks on receive can be running at the same
time as a process that is sending, or even that multiple receives can
be checking signatures at the same time, clobbering the same data
structures.

While we're at it, clean up the comments over cifs_calculate_signature
and add a note that the srv_mutex should be held when calling this
function.

This patch seems to fix the problems for me, but I'm not clear on
whether it's the best approach. If it is, then this should probably
go to stable too.

Cc: stable@kernel.org
Cc: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Minor revision to the original patch. Don't abuse the __le16 variable
on the stack by casting it to wchar_t and handing it off to char2uni.
Declare an actual wchar_t on the stack instead. This fixes a valid
sparse warning.

Fix the spelling of UNI_ASTERISK. Eliminate the unneeded len_remaining
variable in cifsConvertToUCS.

Also, as David Howells points out. We were better off making
cifsConvertToUCS *not* use put_unaligned_le16 since it means that we
can't optimize the mapped characters at compile time. Switch them
instead to use cpu_to_le16, and simply use put_unaligned to set them
in the string.
Reported-and-acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Thus spake David Howells:

The code that follows this:

  	remaining = total_data_size - data_in_this_rsp;
	if (remaining == 0)
		return 0;
	else if (remaining < 0) {

generates better code if you drop the 'remaining' variable and compare
the values directly.

Clean it up per his recommendation...
Reported-and-acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Commit 522440ed made cifs set backing_dev_info on the mapping attached
to new inodes. This change caused a fairly significant read performance
regression, as cifs started doing page-sized reads exclusively.

By virtue of the fact that they're allocated as part of cifs_sb_info by
kzalloc, the ra_pages on cifs BDIs get set to 0, which prevents any
readahead. This forces the normal read codepaths to use readpage instead
of readpages causing a four-fold increase in the number of read calls
with the default rsize.

Fix it by setting ra_pages in the BDI to the same value as that in the
default_backing_dev_info.

Fixes https://bugzilla.kernel.org/show_bug.cgi?id=31662

Cc: stable@kernel.org
Reported-and-Tested-by: NTill <till2.schaefer@uni-dortmund.de>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The BCC is still __le16 at this point, and in any case we need to
use the get_bcc_le macro to make sure we don't hit alignment
problems.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Currently, we skip doing the is_path_accessible check in cifs_mount if
there is no prefixpath. I have a report of at least one server however
that allows a TREE_CONNECT to a share that has a DFS referral at its
root. The reporter in this case was using a UNC that had no prefixpath,
so the is_path_accessible check was not triggered and the box later hit
a BUG() because we were chasing a DFS referral on the root dentry for
the mount.

This patch fixes this by removing the check for a zero-length
prefixpath.  That should make the is_path_accessible check be done in
this situation and should allow the client to chase the DFS referral at
mount time instead.

Cc: stable@kernel.org
Reported-and-Tested-by: NYogesh Sharma <ysharma@cymer.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

make modules C=2 M=fs/cifs CF=-D__CHECK_ENDIAN__

Found for example:

 CHECK   fs/cifs/cifssmb.c
fs/cifs/cifssmb.c:728:22: warning: incorrect type in assignment (different base types)
fs/cifs/cifssmb.c:728:22:    expected unsigned short [unsigned] [usertype] Tid
fs/cifs/cifssmb.c:728:22:    got restricted __le16 [usertype] <noident>
fs/cifs/cifssmb.c:1883:45: warning: incorrect type in assignment (different base types)
fs/cifs/cifssmb.c:1883:45:    expected long long [signed] [usertype] fl_start
fs/cifs/cifssmb.c:1883:45:    got restricted __le64 [usertype] start
fs/cifs/cifssmb.c:1884:54: warning: restricted __le64 degrades to integer
fs/cifs/cifssmb.c:1885:58: warning: restricted __le64 degrades to integer
fs/cifs/cifssmb.c:1886:43: warning: incorrect type in assignment (different base types)
fs/cifs/cifssmb.c:1886:43:    expected unsigned int [unsigned] fl_pid
fs/cifs/cifssmb.c:1886:43:    got restricted __le32 [usertype] pid

In checking new smb2 code for missing endian conversions, I noticed
some endian errors had crept in over the last few releases into the
cifs code (symlink, ntlmssp, posix lock, and also a less problematic warning
in fscache).  A followon patch will address a few smb2 endian
problems.
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Ports are __be16 not unsigned short int

Eliminates the remaining fixable endian warnings:

~/cifs-2.6$ make modules C=1 M=fs/cifs CF=-D__CHECK_ENDIAN__
  CHECK   fs/cifs/connect.c
fs/cifs/connect.c:2408:23: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2408:23:    expected unsigned short *sport
fs/cifs/connect.c:2408:23:    got restricted __be16 *<noident>
fs/cifs/connect.c:2410:23: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2410:23:    expected unsigned short *sport
fs/cifs/connect.c:2410:23:    got restricted __be16 *<noident>
fs/cifs/connect.c:2416:24: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2416:24:    expected unsigned short [unsigned] [short] <noident>
fs/cifs/connect.c:2416:24:    got restricted __be16 [usertype] <noident>
fs/cifs/connect.c:2423:24: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2423:24:    expected unsigned short [unsigned] [short] <noident>
fs/cifs/connect.c:2423:24:    got restricted __be16 [usertype] <noident>
fs/cifs/connect.c:2326:23: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2326:23:    expected unsigned short [unsigned] sport
fs/cifs/connect.c:2326:23:    got restricted __be16 [usertype] sin6_port
fs/cifs/connect.c:2330:23: warning: incorrect type in assignment (different base types)
fs/cifs/connect.c:2330:23:    expected unsigned short [unsigned] sport
fs/cifs/connect.c:2330:23:    got restricted __be16 [usertype] sin_port
fs/cifs/connect.c:2394:22: warning: restricted __be16 degrades to integer
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Max share name was set to 64, and (at least for Windows)
can be 80.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

We artificially limited the user name to 32 bytes, but modern servers handle
larger.  Set the maximum length to a reasonable 256, and make the user name
string dynamically allocated rather than a fixed size in session structure.
Also clean up old checkpatch warning.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

This flag currently only affects whether we allow "zero-copy" writes
with signing enabled. Typically we map pages in the pagecache directly
into the write request. If signing is enabled however and the contents
of the page change after the signature is calculated but before the
write is sent then the signature will be wrong. Servers typically
respond to this by closing down the socket.

Still, this can provide a performance benefit so the "Experimental" flag
was overloaded to allow this. That's really not a good place for this
option however since it's not clear what that flag does.

Move that flag instead to a new module parameter that better describes
its purpose. That's also better since it can be set at module insertion
time by configuring modprobe.d.
Reviewed-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

cifs_close doesn't check that the filp->private_data is non-NULL before
trying to put it. That can cause an oops in certain error conditions
that can occur on open or lookup before the private_data is set.
Reported-by: NBen Greear <greearb@candelatech.com>
CC: Stable <stable@kernel.org>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

ia64 throws away .exit sections for the built-in CONFIG case, so routines
that are used in other circumstances should not be tagged as __exit.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Revert commit 6de9843d, since it
caused a data corruption regression with BitTorrent downloads.  Thanks
to Damien for discovering and bisecting to find the problem commit.

https://bugzilla.kernel.org/show_bug.cgi?id=32972Reported-by: NDamien Grassart <damien@grassart.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

We can create 4402345721856 byte file with indirect block mapping.
However, if we grow an indirect-block file to the size with ftruncate(),
we can see an ext4 warning. The following patch fixes this problem.

How to reproduce:
# dd if=/dev/zero of=/mnt/mp1/hoge bs=1 count=0 seek=4402345721856
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000221428 s, 0.0 kB/s
# tail -n 1 /var/log/messages
Nov 25 15:10:27 test kernel: EXT4-fs warning (device sda8): ext4_block_to_path:345: block 1074791436 > max in inode 12
Signed-off-by: NKazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

ext4_journal_start_sb() should not prevent an active handle from being
started due to s_frozen.  Otherwise, deadlock is easy to happen, below
is a situation.

================================================
     freeze         |       truncate
================================================
                    |  ext4_ext_truncate()
    freeze_super()  |   starts a handle
    sets s_frozen   |
                    |  ext4_ext_truncate()
                    |  holds i_data_sem
  ext4_freeze()     |
  waits for updates |
                    |  ext4_free_blocks()
                    |  calls dquot_free_block()
                    |
                    |  dquot_free_blocks()
                    |  calls ext4_dirty_inode()
                    |
                    |  ext4_dirty_inode()
                    |  trys to start an active
                    |  handle
                    |
                    |  block due to s_frozen
================================================
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reported-by: NAmir Goldstein <amir73il@users.sf.net>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NAndreas Dilger <adilger@dilger.ca>

ext4 has taken the stance that, in the absence of a journal,
when an fsync/fdatasync of an inode is done, the parent
directory should be sync'ed if this inode entry is new.
ext4_sync_parent(), which implements this, does indeed sync
the dirent pages for parent directories, but it does not
sync the directory *inode*.  This patch fixes this.

Also now return error status from ext4_sync_parent().

I tested this using a power fail test, which panics a
machine running a file server getting requests from a
client.  Without this patch, on about every other test run,
the server is missing many, many files that had been synced.
With this patch, on > 6 runs, I see zero files being lost.

Google-Bug-Id: 4179519
Signed-off-by: NCurt Wohlgemuth <curtw@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Lock stateid's can have access_bmap 0 if they were only partially
initialized (due to a failed lock request); handle that case in
free_generic_stateid.

------------[ cut here ]------------
kernel BUG at fs/nfsd/nfs4state.c:380!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/kernel/mm/ksm/run
Modules linked in: nfs fscache md4 nls_utf8 cifs ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat bridge stp llc nfsd lockd nfs_acl auth_rpcgss sunrpc ipv6 ppdev parport_pc parport pcnet32 mii pcspkr microcode i2c_piix4 BusLogic floppy [last unloaded: mperf]

Pid: 1468, comm: nfsd Not tainted 2.6.38+ #120 VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform
EIP: 0060:[<e24f180d>] EFLAGS: 00010297 CPU: 0
EIP is at nfs4_access_to_omode+0x1c/0x29 [nfsd]
EAX: ffffffff EBX: dd758120 ECX: 00000000 EDX: 00000004
ESI: dd758120 EDI: ddfe657c EBP: dd54dde0 ESP: dd54dde0
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process nfsd (pid: 1468, ti=dd54c000 task=ddc92580 task.ti=dd54c000)
Stack:
 dd54ddf0 e24f19ca 00000000 ddfe6560 dd54de08 e24f1a5d dd758130 deee3a20
 ddfe6560 31270000 dd54df1c e24f52fd 0000000f dd758090 e2505dd0 0be304cf
 dbb51d68 0000000e ddfe657c ddcd8020 dd758130 dd758128 dd7580d8 dd54de68
Call Trace:
 [<e24f19ca>] free_generic_stateid+0x1c/0x3e [nfsd]
 [<e24f1a5d>] release_lockowner+0x71/0x8a [nfsd]
 [<e24f52fd>] nfsd4_lock+0x617/0x66c [nfsd]
 [<e24e57b6>] ? nfsd_setuser+0x199/0x1bb [nfsd]
 [<e24e056c>] ? nfsd_setuser_and_check_port+0x65/0x81 [nfsd]
 [<c07a0052>] ? _cond_resched+0x8/0x1c
 [<c04ca61f>] ? slab_pre_alloc_hook.clone.33+0x23/0x27
 [<c04cac01>] ? kmem_cache_alloc+0x1a/0xd2
 [<c04835a0>] ? __call_rcu+0xd7/0xdd
 [<e24e0dfb>] ? fh_verify+0x401/0x452 [nfsd]
 [<e24f0b61>] ? nfsd4_encode_operation+0x52/0x117 [nfsd]
 [<e24ea0d7>] ? nfsd4_putfh+0x33/0x3b [nfsd]
 [<e24f4ce6>] ? nfsd4_delegreturn+0xd4/0xd4 [nfsd]
 [<e24ea2c9>] nfsd4_proc_compound+0x1ea/0x33e [nfsd]
 [<e24de6ee>] nfsd_dispatch+0xd1/0x1a5 [nfsd]
 [<e1d6e1c7>] svc_process_common+0x282/0x46f [sunrpc]
 [<e1d6e578>] svc_process+0xdc/0xfa [sunrpc]
 [<e24de0fa>] nfsd+0xd6/0x115 [nfsd]
 [<e24de024>] ? nfsd_shutdown+0x24/0x24 [nfsd]
 [<c0454322>] kthread+0x62/0x67
 [<c04542c0>] ? kthread_worker_fn+0x114/0x114
 [<c07a6ebe>] kernel_thread_helper+0x6/0x10
Code: eb 05 b8 00 00 27 4f 8d 65 f4 5b 5e 5f 5d c3 83 e0 03 55 83 f8 02 89 e5 74 17 83 f8 03 74 05 48 75 09 eb 09 b8 02 00 00 00 eb 0b <0f> 0b 31 c0 eb 05 b8 01 00 00 00 5d c3 55 89 e5 57 56 89 d6 8d
EIP: [<e24f180d>] nfs4_access_to_omode+0x1c/0x29 [nfsd] SS:ESP 0068:dd54dde0
---[ end trace 2b0bf6c6557cb284 ]---

The trace route is:

 -> nfsd4_lock()
   -> if (lock->lk_is_new) {
     -> alloc_init_lock_stateid()

        3739: stp->st_access_bmap = 0;

   ->if (status && lock->lk_is_new && lock_sop)
     -> release_lockowner()
      -> free_generic_stateid()
       -> nfs4_access_bmap_to_omode()
          -> nfs4_access_to_omode()

        380: BUG();   *****

This problem was introduced by 0997b173.
Reported-by: NMi Jinlong <mijinlong@cn.fujitsu.com>
Tested-by: NMi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Add proper blk_start_plug/blk_finish_plug pairs for the two places where
we issue buffer I/O, and remove the blk_flush_plug in xfs_buf_lock and
xfs_buf_iowait, given that context switches already flush the per-process
plugging lists.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

For a CONFIG_XFS_DEBUG=n build gcc complains about statements with no
effect in xfs_debug:

fs/xfs/quota/xfs_qm_syscalls.c: In function 'xfs_qm_scall_trunc_qfiles':
fs/xfs/quota/xfs_qm_syscalls.c:291:3: warning: statement with no effect

The reason for that is that the various new xfs message functions have a
return value which is never used, and in case of the non-debug build
xfs_debug the macro evaluates to a plain 0 which produces the above
warnings.  This can be fixed by turning xfs_debug into an inline function
instead of a macro, but in addition to that I've also changed all the
message helpers to return void as we never use their return values.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

GCC 4.6 now warnings about variables set but not used.  Fix the trivially
fixable warnings of this sort.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

On the Power platform, the log tail debug checks fire excessively
causing the system to panic early in testing. The debug checks are
known to be racy, though on x86_64 there is no evidence that they
trigger at all.

We want to keep the checks active on debug systems to alert us to
problems with log space accounting, but we need to reduce the impact
of a racy check on testing on the Power platform.

As a result, convert the ASSERT conditions to warnings, and
allow them to fire only once per filesystem mount. This will prevent
false positives from interfering with testing, whilst still
providing us with the indication that they may be a problem with log
space accounting should that occur.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

A fuzzed filesystem crashed a kernel when freeing an extent with a
block number beyond the end of the filesystem. Convert all the debug
asserts in xfs_free_extent() to active checks so that we catch bad
extents and return that the filesytsem is corrupted rather than
crashing.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

When we are short on memory, we want to expedite the cleaning of
dirty objects.  Hence when we run short on memory, we need to kick
the AIL flushing into action to clean as many dirty objects as
quickly as possible.  To implement this, sample the lsn of the log
item at the head of the AIL and use that as the push target for the
AIL flush.

Further, we keep items in the AIL that are dirty that are not
tracked any other way, so we can get objects sitting in the AIL that
don't get written back until the AIL is pushed. Hence to get the
filesystem to the idle state, we might need to push the AIL to flush
out any remaining dirty objects sitting in the AIL. This requires
the same push mechanism as the reclaim push.

This patch also renames xfs_trans_ail_tail() to xfs_ail_min_lsn() to
match the new xfs_ail_max_lsn() function introduced in this patch.
Similarly for xfs_trans_ail_push -> xfs_ail_push.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NAlex Elder <aelder@sgi.com>

This patch rearranges the location of functions in xfs_trans_ail.c
to remove the need for forward declarations of those functions in
preparation for adding new functions without the need for forward
declarations.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NAlex Elder <aelder@sgi.com>

Similar to the xfssyncd, the per-filesystem xfsaild threads can be
converted to a global workqueue and run periodically by delayed
works. This makes sense for the AIL pushing because it uses
variable timeouts depending on the work that needs to be done.

By removing the xfsaild, we simplify the AIL pushing code and
remove the need to spread the code to implement the threading
and pushing across multiple files.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

Background inode reclaim needs to run more frequently that the XFS
syncd work is run as 30s is too long between optimal reclaim runs.
Add a new periodic work item to the xfs syncd workqueue to run a
fast, non-blocking inode reclaim scan.

Background inode reclaim is kicked by the act of marking inodes for
reclaim.  When an AG is first marked as having reclaimable inodes,
the background reclaim work is kicked. It will continue to run
periodically untill it detects that there are no more reclaimable
inodes. It will be kicked again when the first inode is queued for
reclaim.

To ensure shrinker based inode reclaim throttles to the inode
cleaning and reclaim rate but still reclaim inodes efficiently, make it kick the
background inode reclaim so that when we are low on memory we are
trying to reclaim inodes as efficiently as possible. This kick shoul
d not be necessary, but it will protect against failures to kick the
background reclaim when inodes are first dirtied.

To provide the rate throttling, make the shrinker pass do
synchronous inode reclaim so that it blocks on inodes under IO. This
means that the shrinker will reclaim inodes rather than just
skipping over them, but it does not adversely affect the rate of
reclaim because most dirty inodes are already under IO due to the
background reclaim work the shrinker kicked.

These two modifications solve one of the two OOM killer invocations
Chris Mason reported recently when running a stress testing script.
The particular workload trigger for the OOM killer invocation is
where there are more threads than CPUs all unlinking files in an
extremely memory constrained environment. Unlike other solutions,
this one does not have a performance impact on performance when
memory is not constrained or the number of concurrent threads
operating is <= to the number of CPUs.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

On of the problems with the current inode flush at ENOSPC is that we
queue a flush per ENOSPC event, regardless of how many are already
queued. Thi can result in    hundreds of queued flushes, most of
which simply burn CPU scanned and do no real work. This simply slows
down allocation at ENOSPC.

We really only need one active flush at a time, and we can easily
implement that via the new xfs_syncd_wq. All we need to do is queue
a flush if one is not already active, then block waiting for the
currently active flush to complete. The result is that we only ever
have a single ENOSPC inode flush active at a time and this greatly
reduces the overhead of ENOSPC processing.

On my 2p test machine, this results in tests exercising ENOSPC
conditions running significantly faster - 042 halves execution time,
083 drops from 60s to 5s, etc - while not introducing test
regressions.

This allows us to remove the old xfssyncd threads and infrastructure
as they are no longer used.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>

All of the work xfssyncd does is background functionality. There is
no need for a thread per filesystem to do this work - it can al be
managed by a global workqueue now they manage concurrency
effectively.

Introduce a new gglobal xfssyncd workqueue, and convert the periodic
work to use this new functionality. To do this, use a delayed work
construct to schedule the next running of the periodic sync work
for the filesystem. When the sync work is complete, queue a new
delayed work for the next running of the sync work.

For laptop mode, we wait on completion for the sync works, so ensure
that the sync work queuing interface can flush and wait for work to
complete to enable the work queue infrastructure to replace the
current sequence number and wakeup that is used.

Because the sync work does non-trivial amounts of work, mark the
new work queue as CPU intensive.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>