This patch changes generic_cont_expand(), in order to share the code
with fatfs.

  - Use vmtruncate() if ->prepare_write() returns a error.

Even if ->prepare_write() returns an error, it may already have added some
blocks.  So, this truncates blocks outside of ->i_size by vmtruncate().

  - Add generic_cont_expand_simple().

The generic_cont_expand_simple() assumes that ->prepare_write() can handle
the block boundary.  With this, we don't need to care the extra byte.

And for expanding a file size by truncate(), fatfs uses the
added generic_cont_expand_simple().
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch add to support of ->direct_IO() for mostly read.

The user of this seems to want to use for streaming read.  So, current direct
I/O has limitation, it can only overwrite.  (For write operation, mainly we
need to handle the hole etc..)
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

All EXPORT_SYMBOL of fatfs is only for vfat/msdos. _GPL would be proper.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

We don't need to allocate buffer for checking the buffer is uptodate.  This
use sb_find_get_block() instead, and if it returns NULL it's not uptodate.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It is overkill to update the FS_INFO whenever modifying
prev_free/free_clusters, because those are just a hint.

So, this patch uses ->write_super() for updating FS_INFO instead.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

configurable replacement for slab allocator

This adds a CONFIG_SLAB option under CONFIG_EMBEDDED.  When CONFIG_SLAB is
disabled, the kernel falls back to using the 'SLOB' allocator.

SLOB is a traditional K&R/UNIX allocator with a SLAB emulation layer,
similar to the original Linux kmalloc allocator that SLAB replaced.  It's
signicantly smaller code and is more memory efficient.  But like all
similar allocators, it scales poorly and suffers from fragmentation more
than SLAB, so it's only appropriate for small systems.

It's been tested extensively in the Linux-tiny tree.  I've also
stress-tested it with make -j 8 compiles on a 3G SMP+PREEMPT box (not
recommended).

Here's a comparison for otherwise identical builds, showing SLOB saving
nearly half a megabyte of RAM:

$ size vmlinux*
   text    data     bss     dec     hex filename
3336372  529360  190812 4056544  3de5e0 vmlinux-slab
3323208  527948  190684 4041840  3dac70 vmlinux-slob

$ size mm/{slab,slob}.o
   text    data     bss     dec     hex filename
  13221     752      48   14021    36c5 mm/slab.o
   1896      52       8    1956     7a4 mm/slob.o

/proc/meminfo:
                  SLAB          SLOB      delta
MemTotal:        27964 kB      27980 kB     +16 kB
MemFree:         24596 kB      25092 kB    +496 kB
Buffers:            36 kB         36 kB       0 kB
Cached:           1188 kB       1188 kB       0 kB
SwapCached:          0 kB          0 kB       0 kB
Active:            608 kB        600 kB      -8 kB
Inactive:          808 kB        812 kB      +4 kB
HighTotal:           0 kB          0 kB       0 kB
HighFree:            0 kB          0 kB       0 kB
LowTotal:        27964 kB      27980 kB     +16 kB
LowFree:         24596 kB      25092 kB    +496 kB
SwapTotal:           0 kB          0 kB       0 kB
SwapFree:            0 kB          0 kB       0 kB
Dirty:               4 kB         12 kB      +8 kB
Writeback:           0 kB          0 kB       0 kB
Mapped:            560 kB        556 kB      -4 kB
Slab:             1756 kB          0 kB   -1756 kB
CommitLimit:     13980 kB      13988 kB      +8 kB
Committed_AS:     4208 kB       4208 kB       0 kB
PageTables:         28 kB         28 kB       0 kB
VmallocTotal:  1007312 kB    1007312 kB       0 kB
VmallocUsed:        48 kB         48 kB       0 kB
VmallocChunk:  1007264 kB    1007264 kB       0 kB

(this work has been sponsored in part by CELF)

From: Ingo Molnar <mingo@elte.hu>

   Fix 32-bitness bugs in mm/slob.c.
Signed-off-by: NMatt Mackall <mpm@selenic.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

RCU tasklist_lock and RCU signal handling: send signals RCU-read-locked
instead of tasklist_lock read-locked.  This is a scalability improvement on
SMP and a preemption-latency improvement under PREEMPT_RCU.
Signed-off-by: NPaul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NWilliam Irwin <wli@holomorphy.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Suppress configuration of certain features for the FRV arch as they can't be
built for FRV at the moment:

 (*) RTC

 (*) HISAX_*

 (*) PARPORT_PC

 (*) VGA_CONSOLE

 (*) BINFMT_ELF
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

First discussed at http://marc.theaimsgroup.com/?t=113149255100001&r=1&w=2

- Use the check_range() in mempolicy.c to gather statistics.

- Improve the numa_maps code in general and fix some comments.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add /proc/sys/vm/drop_caches.  When written to, this will cause the kernel to
discard as much pagecache and/or reclaimable slab objects as it can.  THis
operation requires root permissions.

It won't drop dirty data, so the user should run `sync' first.

Caveats:

a) Holds inode_lock for exorbitant amounts of time.

b) Needs to be taught about NUMA nodes: propagate these all the way through
   so the discarding can be controlled on a per-node basis.

This is a debugging feature: useful for getting consistent results between
filesystem benchmarks.  We could possibly put it under a config option, but
it's less than 300 bytes.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch should fix compilation failure of fs/ufs/dir.c with defined UFS_DIR_DEBUG
Signed-off-by: NEvgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 If the loop errors, we need to exit.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 If someone changes the uid/gid mapping in userland, then we do eventually
 want those changes to be propagated to the kernel. Currently the kernel
 assumes that it may cache entries forever.

 Add an expiration time + garbage collector for idmap entries.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

 inode->i_mode contains a lot more than just the mode bits. Make sure that
 we mask away this extra stuff in SETATTR calls to the server.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Clean up: Every ULP that uses the in-kernel RPC client, except the NLM
 client, sets cl_chatty.  There's no reason why NLM shouldn't set it, so
 just get rid of cl_chatty and always be verbose.

 Test-plan:
 Compile with CONFIG_NFS enabled.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 We'd like to hide fields in rpc_xprt and rpc_clnt from upper layer protocols.
 Start by creating an API to force RPC rebind, replacing logic that simply
 sets cl_port to zero.

 Test-plan:
 Destructive testing (unplugging the network temporarily).  Connectathon
 with UDP and TCP.  NFSv2/3 and NFSv4 mounting should be carefully checked.
 Probably need to rig a server where certain services aren't running, or
 that returns an error for some typical operation.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Thanks to Ed Keizer for bug and root cause.  He says: "... we could only mount
 the top-level Solaris share. We could not mount deeper into the tree.
 Investigation showed that Solaris allows UNIX authenticated FSINFO only on the
 top level of the share. This is a problem because we share/export our home
 directories one level higher than we mount them. I.e. we share the partition
 and not the individual home directories. This prevented access to home
 directories."

 We still may need to try auth_sys for the case where the client doesn't have
 appropriate credentials.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 The procedure that decodes statd sm_notify call seems to be skipping a
 few arguments.  How did this ever work?

 >From folks at Polyserve.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 If the server receives an NLM cancel call and finds no waiting lock to
 cancel, then chances are the lock has already been applied, and the client
 just hadn't yet processed the NLM granted callback before it sent the
 cancel.

 The Open Group text, for example, perimts a server to return either success
 (LCK_GRANTED) or failure (LCK_DENIED) in this case.  But returning an error
 seems more helpful; the client may be able to use it to recognize that a
 race has occurred and to recover from the race.

 So, modify the relevant functions to return an error in this case.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 The fl_next check here is superfluous (and possibly a layering violation).
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Currently when lockd gets an NLM_CANCEL request, it also does an unlock for
 the same range.  This is incorrect.

 The Open Group documentation says that "This procedure cancels an
 *outstanding* blocked lock request."  (Emphasis mine.)

 Also, consider a client that holds a lock on the first byte of a file, and
 requests a lock on the entire file.  If the client cancels that request
 (perhaps because the requesting process is signalled), the server shouldn't
 apply perform an unlock on the entire file, since that will also remove the
 previous lock that the client was already granted.

 Or consider a lock request that actually *downgraded* an exclusive lock to
 a shared lock.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Slightly simpler logic here makes it more trivial to verify that the up's
 and down's are balanced here.  Break out an assignment from a conditional
 while we're at it.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

 ...and ensure that nfs_update_inode() respects wcc
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Upon return of a write delegation, the server will almost always bump the
 change attribute. Ensure that we pick up that change so that we don't
 invalidate our data cache unnecessarily.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 According to RFC3530 we're supposed to cache the change attribute
 at the time the client receives a write delegation.
 If the inode is clean, a CB_GETATTR callback by the server to the
 client is supposed to return the cached change attribute.
 If, OTOH, the inode is dirty, the client should bump the cached
 change attribute by 1.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 ...and avoid calling set_page_dirty on them
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 The SuS states that a call to write() will cause mtime to be updated on
 the file. In order to satisfy that requirement, we need to flush out
 any cached writes in nfs_getattr().
 Speed things up slightly by not committing the writes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

 Most NFS server implementations allow up to 64KB reads and writes on the
 wire.  The Solaris NFS server allows up to a megabyte, for instance.

 Now the Linux NFS client supports transfer sizes up to 1MB, too.  This will
 help reduce protocol and context switch overhead on read/write intensive NFS
 workloads, and support larger atomic read and write operations on servers
 that support them.

 Test-plan:
 Connectathon and iozone on mount point with wsize=rsize>32768 over TCP.
 Tests with NFS over UDP to verify the maximum RPC payload size cap.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 To help NFS users and server developers, make the "inode number mismatch"
 message display more useful information.

 Test-plan:
 None.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 nfs_statfs() generates a log message when GETATTR returns an error.  This
 is usually a useless message.  Make it a dprintk.

 Test plan:
 None
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Red Hat found a problem in the error recovery logic in __init_nfs.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Replace ad hoc write parameter sanity checking in nfs_file_direct_write()
 with a call to generic_write_checks().  This should make the proper checks
 modulo the O_LARGEFILE flag, and should catch NFSv2-specific limitations by
 virtue of i_sb->s_maxbytes.

 Test plan:
 Posix compliance testing with both NFSv2 and NFSv3.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Use a cred from the nfs4_client->cl_state_owners list.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 In RFC3530, the RENEW operation is allowed to use either

 the same principal, RPC security flavour and (if RPCSEC_GSS), the same
  mechanism and service that was used for SETCLIENTID_CONFIRM

 OR

 Any principal, RPC security flavour and service combination that
 currently has an OPEN file on the server.

 Choose the latter since that doesn't require us to keep credentials for
 the same principal for the entire duration of the mount.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

 Convert private implementations in NFSv4 state recovery and delegation
 code to use kthreads.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>