Commit Graph

1730 Commits

Author SHA1 Message Date
Steve French
b7ca692896 CIFS: Protect i_nlink from being negative
that can cause warning messages.  Pavel had initially
suggested a smaller patch around drop_nlink, after
a similar problem was discovered NFS.  Protecting
additional places where nlink is touched was
suggested by Jeff Layton and is included in this.

Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-08-19 22:30:00 -05:00
Pavel Shilovsky
1a500f010f CIFS: Add SMB2 support for rmdir
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-27 15:17:50 -05:00
Pavel Shilovsky
f958ca5d88 CIFS: Move rmdir code to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-27 15:17:47 -05:00
Pavel Shilovsky
a0e731839d CIFS: Add SMB2 support for mkdir operation
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-27 15:17:43 -05:00
Pavel Shilovsky
f436720e94 CIFS: Separate protocol specific part from mkdir
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-27 15:17:40 -05:00
Pavel Shilovsky
ff691e9694 CIFS: Simplify cifs_mkdir call
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-27 15:17:16 -05:00
Jeff Layton
764a1b1ace cifs: ensure that we always do cifsFileInfo_get under the spinlock
The readpages bug is a regression that was introduced in 6993f74a5.
This also fixes a couple of similar bugs in the uncached read and write
codepaths.

Also, prevent this sort of thing in the future by having cifsFileInfo_get
take the spinlock itself, and adding a _locked variant for use in places
that are already holding the lock. The _put code has always done that
so this makes for a less confusing interface.

Cc: <stable@vger.kernel.org> # 3.5.x
Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-25 14:51:30 -05:00
Pavel Shilovsky
29e20f9c65 CIFS: Make CAP_* checks protocol independent
Since both CIFS and SMB2 use ses->capabilities (server->capabilities)
field but flags are different we should make such checks protocol
independent.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 14:12:03 -05:00
Pavel Shilovsky
d60622eb5a CIFS: Allow SMB2 statistics to be tracked
Since there are only 19 command codes, it also is easier to track by exact
command code than it was for cifs.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:20 +04:00
Pavel Shilovsky
44c581866e CIFS: Move clear/print_stats code to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:18 +04:00
Pavel Shilovsky
9094fad1ed CIFS: Add echo request support for SMB2
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:17 +04:00
Pavel Shilovsky
f6d7617862 CIFS: Move echo code to osp struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:15 +04:00
Pavel Shilovsky
c95b8eeda3 CIFS: Add SMB2 support for async requests
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:14 +04:00
Pavel Shilovsky
45740847e2 CIFS: Setup async request in ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:12 +04:00
Pavel Shilovsky
25e266320c CIFS: Add SMB2 support for build_path_to_root
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:11 +04:00
Pavel Shilovsky
9224dfc2f9 CIFS: Move building path to root to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:10 +04:00
Pavel Shilovsky
be4cb9e3d4 CIFS: Query SMB2 inode info
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:08 +04:00
Pavel Shilovsky
1208ef1f76 CIFS: Move query inode info code to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:07 +04:00
Pavel Shilovsky
2503a0dba9 CIFS: Add SMB2 support for is_path_accessible
that needs for a successful mount through SMB2 protocol.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:05 +04:00
Pavel Shilovsky
68889f269b CIFS: Move is_path_accessible to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:04 +04:00
Pavel Shilovsky
af4281dc22 CIFS: Move informational tcon calls to ops struct
and rename variables in cifs_mount.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:02 +04:00
Pavel Shilovsky
b669f33ca6 CIFS: Move getting dfs referalls to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:01 +04:00
Pavel Shilovsky
aa24d1e969 CIFS: Process reconnects for SMB2 shares
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:54:59 +04:00
Pavel Shilovsky
faaf946a7d CIFS: Add tree connect/disconnect capability for SMB2
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:54:58 +04:00
Pavel Shilovsky
5478f9ba9a CIFS: Add session setup/logoff capability for SMB2
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:54:57 +04:00
Pavel Shilovsky
ec2e4523fd CIFS: Add capability to send SMB2 negotiate message
and add negotiate request type to let set_credits know that
we are only on negotiate stage and no need to make a decision
about disabling echos and oplocks.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:54:55 +04:00
Pavel Shilovsky
3792c17328 CIFS: Respect SMB2 header/max header size
Use SMB2 header size values for allocation and memset because they
are bigger and suitable for both CIFS and SMB2.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:54:54 +04:00
Pavel Shilovsky
093b2bdad3 CIFS: Make demultiplex_thread work with SMB2 code
Now we can process SMB2 messages: check message, get message id
and wakeup awaiting routines.

Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:54:52 +04:00
Pavel Shilovsky
4b1241006c CIFS: Fix a wrong pointer in atomic_open
Commit 30d9049474 caused a regression
in cifs open codepath.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:54:26 +04:00
Pavel Shilovsky
28ea5290d7 CIFS: Add SMB2 credits support
For SMB2 protocol we can add more than one credit for one received
request: it depends on CreditRequest field in SMB2 response header.
Also we divide all requests by type: echoes, oplocks and others.
Each type uses its own slot pull.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 10:25:23 -05:00
Pavel Shilovsky
2dc7e1c033 CIFS: Make transport routines work with SMB2
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 10:25:20 -05:00
Steve French
ddfbefbd39 CIFS: Map SMB2 status codes to POSIX errors
Add mapping table for 32 bit SMB2 status codes to linux errors.
Note that SMB2 does not use DOS/OS2 errors (ever) so mapping to
DOS/OS2 errors as a common network subset (as we do for cifs)
doesn't help. And note that the set of status codes is much more
complete here.

Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 10:25:15 -05:00
Pavel Shilovsky
b8030603d9 CIFS: Add SMB2 status codes
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 10:25:13 -05:00
Pavel Shilovsky
f7ec0d0bbc CIFS: Rename 7 error codes to NT_ style
and consider such codes as CIFS errors.

Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 10:25:10 -05:00
Pavel Shilovsky
6d5786a34d CIFS: Rename Get/FreeXid and make them work with unsigned int
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 10:25:08 -05:00
Pavel Shilovsky
2e6e02ab6d CIFS: Move protocol specific tcon/tdis code to ops struct
and rename variables around the code changes.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 10:25:06 -05:00
Pavel Shilovsky
58c45c58a1 CIFS: Move protocol specific session setup/logoff code to ops struct
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 10:25:03 -05:00
Pavel Shilovsky
286170aa24 CIFS: Move protocol specific negotiate code to ops struct
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 00:33:26 -05:00
Pavel Shilovsky
a891f0f895 CIFS: Extend credit mechanism to process request type
Split all requests to echos, oplocks and others - each group uses
its own credit slot. This is indicated by new flags

CIFS_ECHO_OP and CIFS_OBREAK_OP

that are not used now for CIFS. This change is required to support
SMB2 protocol because of different processing of these commands.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 00:32:48 -05:00
Pavel Shilovsky
316cf94a91 CIFS: Move trans2 processing to ops struct
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 00:32:25 -05:00
Jeff Layton
7659624ffb cifs: reinstate sec=ntlmv2 mount option
sec=ntlmv2 as a mount option got dropped in the mount option overhaul.

Cc: Sachin Prabhu <sprabhu@redhat.com>
Cc: <stable@vger.kernel.org> # 3.4+
Reported-by: Günter Kukkukk <linux@kukkukk.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-23 20:48:24 -05:00
Jeff Layton
762a4206a3 cifs: rename cifs_sign_smb2 to cifs_sign_smbv
"smb2" makes me think of the SMB2.x protocol, which isn't at all what
this function is for...

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-23 16:36:34 -05:00
Jeff Layton
d971e0656b cifs: remove bogus reset of smb_buf_length in smb_send routines
There's a comment here about how we don't want to modify this length,
but nothing in this function actually does.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-23 16:36:31 -05:00
Jeff Layton
c5fd363d77 cifs: move file_lock off stack in cifs_push_posix_locks
struct file_lock is pretty large, so we really don't want that on the
stack in a potentially long call chain. Reorganize the arguments to
CIFSSMBPosixLock to eliminate the need for that.

Eliminate the get_flag and simply use a non-NULL pLockInfo to indicate
that this is a "get" operation. In order to do that, need to add a new
loff_t argument for the start_offset.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-23 16:36:29 -05:00
Jeff Layton
ac3aa2f8ae cifs: remove extraneous newlines from cERROR and cFYI calls
Those macros add a newline on their own, so there's not any need to
embed one in the message itself.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-23 16:36:26 -05:00
Jeff Layton
00401ff780 cifs: after upcalling for krb5 creds, invalidate key rather than revoking it
Calling key_revoke here isn't ideal as further requests for the key will
end up returning -EKEYREVOKED until it gets purged from the cache. What we
really intend here is to force a new upcall on the next request_key.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-23 16:36:24 -05:00
Linus Torvalds
a66d2c8f7e Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull the big VFS changes from Al Viro:
 "This one is *big* and changes quite a few things around VFS.  What's in there:

   - the first of two really major architecture changes - death to open
     intents.

     The former is finally there; it was very long in making, but with
     Miklos getting through really hard and messy final push in
     fs/namei.c, we finally have it.  Unlike his variant, this one
     doesn't introduce struct opendata; what we have instead is
     ->atomic_open() taking preallocated struct file * and passing
     everything via its fields.

     Instead of returning struct file *, it returns -E...  on error, 0
     on success and 1 in "deal with it yourself" case (e.g.  symlink
     found on server, etc.).

     See comments before fs/namei.c:atomic_open().  That made a lot of
     goodies finally possible and quite a few are in that pile:
     ->lookup(), ->d_revalidate() and ->create() do not get struct
     nameidata * anymore; ->lookup() and ->d_revalidate() get lookup
     flags instead, ->create() gets "do we want it exclusive" flag.

     With the introduction of new helper (kern_path_locked()) we are rid
     of all struct nameidata instances outside of fs/namei.c; it's still
     visible in namei.h, but not for long.  Come the next cycle,
     declaration will move either to fs/internal.h or to fs/namei.c
     itself.  [me, miklos, hch]

   - The second major change: behaviour of final fput().  Now we have
     __fput() done without any locks held by caller *and* not from deep
     in call stack.

     That obviously lifts a lot of constraints on the locking in there.
     Moreover, it's legal now to call fput() from atomic contexts (which
     has immediately simplified life for aio.c).  We also don't need
     anti-recursion logics in __scm_destroy() anymore.

     There is a price, though - the damn thing has become partially
     asynchronous.  For fput() from normal process we are guaranteed
     that pending __fput() will be done before the caller returns to
     userland, exits or gets stopped for ptrace.

     For kernel threads and atomic contexts it's done via
     schedule_work(), so theoretically we might need a way to make sure
     it's finished; so far only one such place had been found, but there
     might be more.

     There's flush_delayed_fput() (do all pending __fput()) and there's
     __fput_sync() (fput() analog doing __fput() immediately).  I hope
     we won't need them often; see warnings in fs/file_table.c for
     details.  [me, based on task_work series from Oleg merged last
     cycle]

   - sync series from Jan

   - large part of "death to sync_supers()" work from Artem; the only
     bits missing here are exofs and ext4 ones.  As far as I understand,
     those are going via the exofs and ext4 trees resp.; once they are
     in, we can put ->write_super() to the rest, along with the thread
     calling it.

   - preparatory bits from unionmount series (from dhowells).

   - assorted cleanups and fixes all over the place, as usual.

  This is not the last pile for this cycle; there's at least jlayton's
  ESTALE work and fsfreeze series (the latter - in dire need of fixes,
  so I'm not sure it'll make the cut this cycle).  I'll probably throw
  symlink/hardlink restrictions stuff from Kees into the next pile, too.
  Plus there's a lot of misc patches I hadn't thrown into that one -
  it's large enough as it is..."

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (127 commits)
  ext4: switch EXT4_IOC_RESIZE_FS to mnt_want_write_file()
  btrfs: switch btrfs_ioctl_balance() to mnt_want_write_file()
  switch dentry_open() to struct path, make it grab references itself
  spufs: shift dget/mntget towards dentry_open()
  zoran: don't bother with struct file * in zoran_map
  ecryptfs: don't reinvent the wheels, please - use struct completion
  don't expose I_NEW inodes via dentry->d_inode
  tidy up namei.c a bit
  unobfuscate follow_up() a bit
  ext3: pass custom EOF to generic_file_llseek_size()
  ext4: use core vfs llseek code for dir seeks
  vfs: allow custom EOF in generic_file_llseek code
  vfs: Avoid unnecessary WB_SYNC_NONE writeback during sys_sync and reorder sync passes
  vfs: Remove unnecessary flushing of block devices
  vfs: Make sys_sync writeout also block device inodes
  vfs: Create function for iterating over block devices
  vfs: Reorder operations during sys_sync
  quota: Move quota syncing to ->sync_fs method
  quota: Split dquot_quota_sync() to writeback and cache flushing part
  vfs: Move noop_backing_dev_info check from sync into writeback
  ...
2012-07-23 12:27:27 -07:00
Jeff Layton
cd60042cc1 cifs: always update the inode cache with the results from a FIND_*
When we get back a FIND_FIRST/NEXT result, we have some info about the
dentry that we use to instantiate a new inode. We were ignoring and
discarding that info when we had an existing dentry in the cache.

Fix this by updating the inode in place when we find an existing dentry
and the uniqueid is the same.

Cc: <stable@vger.kernel.org> # .31.x
Reported-and-Tested-by: Andrew Bartlett <abartlet@samba.org>
Reported-by: Bill Robertson <bill_robertson@debortoli.com.au>
Reported-by: Dion Edwards <dion_edwards@debortoli.com.au>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-16 23:57:23 -05:00
Jeff Layton
3cf003c08b cifs: when CONFIG_HIGHMEM is set, serialize the read/write kmaps
Jian found that when he ran fsx on a 32 bit arch with a large wsize the
process and one of the bdi writeback kthreads would sometimes deadlock
with a stack trace like this:

crash> bt
PID: 2789   TASK: f02edaa0  CPU: 3   COMMAND: "fsx"
 #0 [eed63cbc] schedule at c083c5b3
 #1 [eed63d80] kmap_high at c0500ec8
 #2 [eed63db0] cifs_async_writev at f7fabcd7 [cifs]
 #3 [eed63df0] cifs_writepages at f7fb7f5c [cifs]
 #4 [eed63e50] do_writepages at c04f3e32
 #5 [eed63e54] __filemap_fdatawrite_range at c04e152a
 #6 [eed63ea4] filemap_fdatawrite at c04e1b3e
 #7 [eed63eb4] cifs_file_aio_write at f7fa111a [cifs]
 #8 [eed63ecc] do_sync_write at c052d202
 #9 [eed63f74] vfs_write at c052d4ee
#10 [eed63f94] sys_write at c052df4c
#11 [eed63fb0] ia32_sysenter_target at c0409a98
    EAX: 00000004  EBX: 00000003  ECX: abd73b73  EDX: 012a65c6
    DS:  007b      ESI: 012a65c6  ES:  007b      EDI: 00000000
    SS:  007b      ESP: bf8db178  EBP: bf8db1f8  GS:  0033
    CS:  0073      EIP: 40000424  ERR: 00000004  EFLAGS: 00000246

Each task would kmap part of its address array before getting stuck, but
not enough to actually issue the write.

This patch fixes this by serializing the marshal_iov operations for
async reads and writes. The idea here is to ensure that cifs
aggressively tries to populate a request before attempting to fulfill
another one. As soon as all of the pages are kmapped for a request, then
we can unlock and allow another one to proceed.

There's no need to do this serialization on non-CONFIG_HIGHMEM arches
however, so optimize all of this out when CONFIG_HIGHMEM isn't set.

Cc: <stable@vger.kernel.org>
Reported-by: Jian Li <jiali@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-16 23:57:14 -05:00
Jeff Layton
3ae629d98b cifs: on CONFIG_HIGHMEM machines, limit the rsize/wsize to the kmap space
We currently rely on being able to kmap all of the pages in an async
read or write request. If you're on a machine that has CONFIG_HIGHMEM
set then that kmap space is limited, sometimes to as low as 512 slots.

With 512 slots, we can only support up to a 2M r/wsize, and that's
assuming that we can get our greedy little hands on all of them. There
are other users however, so it's possible we'll end up stuck with a
size that large.

Since we can't handle a rsize or wsize larger than that currently, cap
those options at the number of kmap slots we have. We could consider
capping it even lower, but we currently default to a max of 1M. Might as
well allow those luddites on 32 bit arches enough rope to hang
themselves.

A more robust fix would be to teach the send and receive routines how
to contend with an array of pages so we don't need to marshal up a kvec
array at all. That's a fairly significant overhaul though, so we'll need
this limit in place until that's ready.

Cc: <stable@vger.kernel.org>
Reported-by: Jian Li <jiali@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-16 23:57:09 -05:00