Commit Graph

24109 Commits

Author SHA1 Message Date
Jeff Layton
66bfaadc3d cifs: tune bdi.ra_pages in accordance with the rsize
Tune bdi.ra_pages to be a multiple of the rsize. This prevents the VFS
from asking for pages that require small reads to satisfy.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:30:35 -04:00
Jeff Layton
5eba8ab360 cifs: allow for larger rsize= options and change defaults
Currently we cap the rsize at a value that fits in CIFSMaxBufSize. That's
not needed any longer for readpages. Allow the use of larger values for
readpages. cifs_iovec_read and cifs_read however are still limited to the
CIFSMaxBufSize. Make sure they don't exceed that.

The patch also changes the rsize defaults. The default when unix
extensions are enabled is set to 1M for parity with the wsize, and there
is a hard cap of ~16M.

When unix extensions are not enabled, the default is set to 60k. According
to MS-CIFS, Windows servers can only send a max of 60k at a time, so
this is more efficient than requesting a larger size. If the user wishes
however, the max can be extended up to 128k - the length of the READ_RSP
header.

Really old servers however require a special hack to ensure that we don't
request too large a read.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:30:26 -04:00
Jeff Layton
690c5e3163 cifs: convert cifs_readpages to use async reads
Now that we have code in place to do asynchronous reads, convert
cifs_readpages to use it. The new cifs_readpages walks the page_list
that gets passed in, locks and adds the pages to the pagecache and
sets up cifs_readdata to handle the reads.

The rest is handled by the cifs_async_readv infrastructure.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:30:16 -04:00
Jeff Layton
e28bc5b1fd cifs: add cifs_async_readv
...which will allow cifs to do an asynchronous read call to the server.
The caller will allocate and set up cifs_readdata for each READ_AND_X
call that should be issued on the wire. The pages passed in are added
to the pagecache, but not placed on the LRU list yet (as we need the
page->lru to keep the pages on the list in the readdata).

When cifsd identifies the mid, it will see that there is a special
receive handler for the call, and use that to receive the rest of the
frame. cifs_readv_receive will then marshal up a kvec array with
kmapped pages from the pagecache, which eliminates one copy of the
data. Once the data is received, the pages are added to the LRU list,
set uptodate, and unlocked.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:30:07 -04:00
Jeff Layton
2ab2593f4b cifs: fix protocol definition for READ_RSP
There is no pad, and it simplifies the code to remove the "Data" field.

None of the existing code relies on these fields, or on the READ_RSP
being a particular length.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:29:59 -04:00
Jeff Layton
44d22d846f cifs: add a callback function to receive the rest of the frame
In order to handle larger SMBs for readpages and other calls, we want
to be able to read into a preallocated set of buffers. Rather than
changing all of the existing code to preallocate buffers however, we
instead add a receive callback function to the MID.

cifsd will call this function once the mid_q_entry has been identified
in order to receive the rest of the SMB. If the mid can't be identified
or the receive pointer is unset, then the standard 3rd phase receive
function will be called.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:29:49 -04:00
Jeff Layton
e9097ab489 cifs: break out 3rd receive phase into separate function
Move the entire 3rd phase of the receive codepath into a separate
function in preparation for the addition of a pluggable receive
function.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:29:40 -04:00
Jeff Layton
c8054ebdb6 cifs: find mid earlier in receive codepath
In order to receive directly into a preallocated buffer, we need to ID
the mid earlier, before the bulk of the response is read. Call the mid
finding routine as soon as we're able to read the mid.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:29:31 -04:00
Jeff Layton
2a37ef94bb cifs: move buffer pointers into TCP_Server_Info
We have several functions that need to access these pointers. Currently
that's done with a lot of double pointer passing. Instead, move them
into the TCP_Server_Info and simplify the handling.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:29:23 -04:00
Jeff Layton
ffc00e27aa cifs: eliminate is_multi_rsp parm to find_cifs_mid
Change find_cifs_mid to only return NULL if a mid could not be found.
If we got part of a multi-part T2 response, then coalesce it and still
return the mid. The caller can determine the T2 receive status from
the flags in the mid.

With this change, there is no need to pass a pointer to "length" as
well so just pass by value. If a mid is found, then we can just mark
it as malformed. If one isn't found, then the value of "length" won't
change anyway.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:29:13 -04:00
Jeff Layton
ea1f4502fc cifs: move mid finding into separate routine
Begin breaking up find_cifs_mid into smaller pieces. The parts that
coalesce T2 responses don't really need to be done under the
GlobalMid_lock anyway. Create a new function that just finds the
mid on the list, and then later takes it off the list if the entire
response has been received.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:29:05 -04:00
Jeff Layton
89482a56a0 cifs: add a third receive phase to cifs_demultiplex_thread
Have the demultiplex thread receive just enough to get to the MID, and
then find it before receiving the rest. Later, we'll use this to swap
in a preallocated receive buffer for some calls.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:28:57 -04:00
Jeff Layton
1041e3f991 cifs: keep a reusable kvec array for receives
Having to continually allocate a new kvec array is expensive. Allocate
one that's big enough, and only reallocate it as needed.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:28:27 -04:00
Jeff Layton
42c4dfc213 cifs: turn read_from_socket into a wrapper around a vectorized version
Eventually we'll want to allow cifsd to read data directly into the
pagecache. In order to do that we'll need a routine that can take a
kvec array and pass that directly to kernel_recvmsg.

Unfortunately though, the kernel's recvmsg routines modify the kvec
array that gets passed in, so we need to use a copy of the kvec array
and refresh that copy on each pass through the loop.

Reviewed-and-Tested-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2011-10-19 15:28:17 -04:00
Dan Carpenter
7748dd6eab CIFS: cleanup min_t() cast in cifs_read()
Smatch complains that the cast to "int" in min_t() changes very large
values of current_read_size into negative values and so min_t()
could return the wrong value.  I removed the const as well, as that
doesn't do anything here.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-18 10:33:44 -05:00
Shirish Pargaonkar
a5ff376966 cifs: Call id to SID mapping functions to change owner/group (try #4 repost)
Now build security descriptor to change either owner or group at the
server.  Initially security descriptor was built to change only
(D)ACL, that functionality has been extended.

When either an Owner or a Group of a file object at the server is changed,
rest of security descriptor remains same (DACL etc.).

To set security descriptor, it is necessary to open that file
with permission bits of either WRITE_DAC if DACL is being modified or
WRITE_OWNER (Take Ownership) if Owner or Group is being changed.

It is the server that decides whether a set security descriptor with
either owner or group change succeeds or not.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-17 09:11:11 -05:00
Pavel Shilovsky
d59dad2be0 CIFS: Move byte range lock list from fd to inode
that let us do local lock checks before requesting to the server.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-13 19:52:47 -05:00
Jeff Layton
fe11e4ccb8 cifs: clean up check_rfc1002_header
Rename it for better clarity as to what it does and have the caller pass
in just the single type byte. Turn the if statement into a switch and
optimize it by placing the most common message type at the top. Move the
header length check back into cifs_demultiplex_thread in preparation
for adding a new receive phase and normalize the cFYI messages.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-13 18:44:40 -05:00
Pavel Shilovsky
03776f4516 CIFS: Simplify byte range locking code
Split cifs_lock into several functions and let CIFSSMBLock get pid
as an argument.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-13 17:16:28 -05:00
Pavel Shilovsky
94443f4340 CIFS: Fix incorrect max RFC1002 write size value
..the length field has only 17 bits.

Cc: <stable@kernel.org>
Acked-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-13 15:20:14 -05:00
Jeff Layton
a52c1eb7ae cifs: simplify read_from_socket
Move the iovec handling entirely into read_from_socket. That simplifies
the code and gets rid of the special handling for header reads. With
this we can also get rid of the "goto incomplete_rcv" label in the main
demultiplex thread function since we can now treat header and non-header
receives the same way.

Also, make it return an int (since we'll never receive enough to worry
about the sign bit anyway), and simply make it return the amount of bytes
read or a negative error code.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-13 00:05:59 -05:00
Shirish Pargaonkar
21fed0d5b7 cifs: Add data structures and functions for uid/gid to SID mapping (try #4)
Add data structures and functions necessary to map a uid and gid to SID.
These functions are very similar to the ones used to map a SID to uid and gid.
This time, instead of storing sid to id mapping sorted on a sid value,
id to sid is stored, sorted on an id.
A cifs upcall sends an id (uid or gid) and expects a SID structure
in return, if mapping was done successfully.

A failed id to sid mapping to EINVAL.

This patchset aims to enable chown and chgrp commands when
cifsacl mount option is specified, especially to Windows SMB servers.
Currently we can't do that.  So now along with chmod command,
chown and chgrp work.

Winbind is used to map id to a SID.  chown and chgrp use an upcall
to provide an id to winbind and upcall returns with corrosponding
SID if any exists. That SID is used to build security descriptor.
The DACL part of a security descriptor is not changed by either
chown or chgrp functionality.

cifs client maintains a separate caches for uid to SID and
gid to SID mapping. This is similar to the one used earlier
to map SID to id (as part of ID mapping code).

I tested it by mounting shares from a Windows (2003) server by
authenticating as two users, one at a time, as Administrator and
as a ordinary user.
And then attempting to change owner of a file on the share.

Depending on the permissions/privileges at the server for that file,
chown request fails to either open a file (to change the ownership)
or to set security descriptor.
So it all depends on privileges on the file at the server and what
user you are authenticated as at the server, cifs client is just a
conduit.

I compared the security descriptor during chown command to that
what smbcacls sends when it is used with -M OWNNER: option
and they are similar.

This patchset aim to enable chown and chgrp commands when
cifsacl mount option is specified, especially to Windows SMB servers.
Currently we can't do that.  So now along with chmod command,
chown and chgrp work.

I tested it by mounting shares from a Windows (2003) server by
authenticating as two users, one at a time, as Administrator and
as a ordinary user.
And then attempting to change owner of a file on the share.

Depending on the permissions/privileges at the server for that file,
chown request fails to either open a file (to change the ownership)
or to set security descriptor.
So it all depends on privileges on the file at the server and what
user you are authenticated as at the server, cifs client is just a
conduit.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:45:39 -05:00
Steve French
20c3a200c4 Typo in cifs readme in name of module parm directory
Suresh had a typo in his recent patch adding information on
the new oplock_endabled parm. Should be documented as in
directory /sys/module/cifs/parameters not /proc/module/cifs/parameters

Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:42:26 -05:00
Shirish Pargaonkar
d026168692 cifs: clean up unused encryption code
Remove unsed  #if 0 encryption code.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:42:21 -05:00
Shirish Pargaonkar
3d3ea8e64e cifs: Add mount options for backup intent (try #6)
Add mount options backupuid and backugid.

It allows an authenticated user to access files with the intent to back them
up including their ACLs, who may not have access permission but has
"Backup files and directories user right" on them (by virtue of being part
of the built-in group Backup Operators.

When mount options backupuid is specified, cifs client restricts the
use of backup intents to the user whose effective user id is specified
along with the mount option.

When mount options backupgid is specified, cifs client restricts the
use of backup intents to the users whose effective user id belongs to the
group id specified along with the mount option.

If an authenticated user is not part of the built-in group Backup Operators
at the server, access to such files is denied, even if allowed by the client.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:42:17 -05:00
Suresh Jayaraman
8bc4392a1e cifs: warn about deprecation of /proc/fs/cifs/OplockEnabled interface
The plan is to deprecate this interface by kernel version 3.4.

Changes since v1
   - add a '\n' to the printk.

Reported-by: Alexander Swen <alex@swen.nu>
Cc: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:42:13 -05:00
Suresh Jayaraman
c9c4708fdf cifs: update README about the kernel module parameters
Reported-by: Alexander Swen <alex@swen.nu>
Cc: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:42:09 -05:00
Steve French
e75047344e add new module parameter 'enable_oplocks'
Thus spake Jeff Layton:

"Making that a module parm would allow you to set that parameter at boot
time without needing to add special startup scripts. IMO, all of the
procfile "switches" under /proc/fs/cifs should be module parms
instead."

This patch doesn't alter the default behavior (Oplocks are enabled by
default).

To disable oplocks when loading the module, use

   modprobe cifs enable_oplocks=0

(any of '0' or 'n' or 'N' conventions can be used).

To disable oplocks at runtime using the new interface, use

   echo 0 > /sys/module/cifs/parameters/enable_oplocks

The older /proc/fs/cifs/OplockEnabled interface will be deprecated
after two releases. A subsequent patch will add an warning message
about this deprecation.

Changes since v2:
   - make enable_oplocks a 'bool'

Changes since v1:
   - eliminate the use of extra variable by renaming the old one to
     enable_oplocks and make it an 'int' type.

Reported-by: Alexander Swen <alex@swen.nu>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:42:05 -05:00
Jeff Layton
ba749e6d52 cifs: check for unresponsive server every time we call kernel_recvmsg
If the server stops sending data while in the middle of sending a
response then we still want to reconnect it if it doesn't come back.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:59 -05:00
Jeff Layton
e831e6cf3a cifs: make smb_msg local to read_from_socket
If msg_controllen is 0, then the socket layer should never touch these
fields. Thus, there's no need to continually reset them. Also, there's
no need to keep this field on the stack for the demultiplex thread, just
make it a local variable in read_from_socket.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:54 -05:00
Jeff Layton
e2218eab20 cifs: trivial: remove obsolete comment
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:47 -05:00
Jeff Layton
826a95e4a3 cifs: consolidate signature generating code
We have two versions of signature generating code. A vectorized and
non-vectorized version. Eliminate a large chunk of cut-and-paste
code by turning the non-vectorized version into a wrapper around the
vectorized one.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:41 -05:00
Jeff Layton
376b43f41c cifs: clean up checkSMB
The variable names in this function are so ambiguous that it's very
difficult to know what it's doing. Rename them to make it a bit more
clear.

Also, remove a redundant length check. cifsd checks to make sure that
the rfclen isn't larger than the maximum frame size when it does the
receive.

Finally, change checkSMB to return a real error code (-EIO) when
it finds an error. That will help simplify some coming changes in the
callers.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:36 -05:00
Jeff Layton
c974befa40 cifs: untangle server->maxBuf and CIFSMaxBufSize
server->maxBuf is the maximum SMB size (including header) that the
server can handle. CIFSMaxBufSize is the maximum amount of data (sans
header) that the client can handle. Currently maxBuf is being capped at
CIFSMaxBufSize + the max headers size, and the two values are used
somewhat interchangeably in the code.

This makes little sense as these two values are not related at all.
Separate them and make sure the code uses the right values in the right
places.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:32 -05:00
Paul Bolle
f3a6a60e4c cifs: Fix typo 'CIFS_NFSD_EXPORT'
It should be 'CONFIG_CIFS_NFSD_EXPORT'. No-one noticed because that
symbol depends on BROKEN.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:27 -05:00
Jeff Layton
4a29a0bd1d cifs: get rid of unused xid in cifs_get_root
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:22 -05:00
Jeff Layton
b4dacbc282 cifs: use memcpy for magic string in cifs signature generation BSRSPYL
...it's more efficient since we know the length.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:18 -05:00
Jeff Layton
ac423446d8 cifs: switch CIFSSMBQAllEAs to use memcmp
...as that's more efficient when we know that the lengths are equal.

Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:14 -05:00
Sachin Prabhu
875cd04381 cifs: Display strictcache mount option in /proc/mounts
Commit d39454ffe4 adds a strictcache mount
option. This patch allows the display of this mount option in
/proc/mounts when listing shares mounted with the strictcache mount
option.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-11 13:13:18 -05:00
Linus Torvalds
65112dccf8 Merge git://git.samba.org/sfrench/cifs-2.6
* git://git.samba.org/sfrench/cifs-2.6:
  [CIFS] Fix first time message on mount, ntlmv2 upgrade delayed to 3.2
2011-10-10 14:53:11 +12:00
Steve French
9d1e397b7b [CIFS] Fix first time message on mount, ntlmv2 upgrade delayed to 3.2
Microsoft has a bug with ntlmv2 that requires use of ntlmssp, but
we didn't get the required information on when/how to use ntlmssp to
old (but once very popular) legacy servers (various NT4 fixpacks
for example) until too late to merge for 3.1.  Will upgrade
to NTLMv2 in NTLMSSP in 3.2

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
2011-10-07 20:17:56 -05:00
Linus Torvalds
7fd21be75d Merge branch 'btrfs-3.0' of git://github.com/chrismason/linux
* 'btrfs-3.0' of git://github.com/chrismason/linux:
  Btrfs: force a page fault if we have a shorty copy on a page boundary
2011-10-03 12:17:44 -07:00
Josef Bacik
b6316429af Btrfs: force a page fault if we have a shorty copy on a page boundary
A user reported a problem where ceph was getting into 100% cpu usage while doing
some writing.  It turns out it's because we were doing a short write on a not
uptodate page, which means we'd fall back at one page at a time and fault the
page in.  The problem is our position is on the page boundary, so our fault in
logic wasn't actually reading the page, so we'd just spin forever or until the
page got read in by somebody else.  This will force a readpage if we end up
doing a short copy.  Alexandre could reproduce this easily with ceph and reports
it fixes his problem.  I also wrote a reproducer that no longer hangs my box
with this patch.  Thanks,

Reported-and-tested-by: Alexandre Oliva <aoliva@redhat.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-09-30 15:23:54 -04:00
Linus Torvalds
b6c8069d35 vfs: remove LOOKUP_NO_AUTOMOUNT flag
That flag no longer makes sense, since we don't look up automount points
as eagerly any more.  Additionally, it turns out that the NO_AUTOMOUNT
handling was buggy to begin with: it would avoid automounting even for
cases where we really *needed* to do the automount handling, and could
return ENOENT for autofs entries that hadn't been instantiated yet.

With our new non-eager automount semantics, one discussion has been
about adding a AT_AUTOMOUNT flag to vfs_fstatat (and thus the
newfstatat() and fstatat64() system calls), but it's probably not worth
it: you can always force at least directory automounting by simply
adding the final '/' to the filename, which works for *all* of the stat
family system calls, old and new.

So AT_NO_AUTOMOUNT (and thus LOOKUP_NO_AUTOMOUNT) really were just a
result of our bad default behavior.

Acked-by: Ian Kent <raven@themaw.net>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-27 08:12:33 -07:00
Trond Myklebust
815d405cef VFS: Fix the remaining automounter semantics regressions
The concensus seems to be that system calls such as stat() etc should
not trigger an automount.  Neither should the l* versions.

This patch therefore adds a LOOKUP_AUTOMOUNT flag to tag those lookups
that _should_ trigger an automount on the last path element.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[ Edited to leave out the cases that are already covered by LOOKUP_OPEN,
  LOOKUP_DIRECTORY and LOOKUP_CREATE - all of which also fundamentally
  force automounting for their own reasons   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-26 19:16:46 -07:00
Linus Torvalds
d94c177bee vfs pathname lookup: Add LOOKUP_AUTOMOUNT flag
Since we've now turned around and made LOOKUP_FOLLOW *not* force an
automount, we want to add the ability to force an automount event on
lookup even if we don't happen to have one of the other flags that force
it implicitly (LOOKUP_OPEN, LOOKUP_DIRECTORY, LOOKUP_PARENT..)

Most cases will never want to use this, since you'd normally want to
delay automounting as long as possible, which usually implies
LOOKUP_OPEN (when we open a file or directory, we really cannot avoid
the automount any more).

But Trond argued sufficiently forcefully that at a minimum bind mounting
a file and quotactl will want to force the automount lookup.  Some other
cases (like nfs_follow_remote_path()) could use it too, although
LOOKUP_DIRECTORY would work there as well.

This commit just adds the flag and logic, no users yet, though.  It also
doesn't actually touch the LOOKUP_NO_AUTOMOUNT flag that is related, and
was made irrelevant by the same change that made us not follow on
LOOKUP_FOLLOW.

Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-26 17:44:55 -07:00
Linus Torvalds
fed678dc8a Merge branch 'for-linus' of git://git.kernel.dk/linux-block
* 'for-linus' of git://git.kernel.dk/linux-block:
  floppy: use del_timer_sync() in init cleanup
  blk-cgroup: be able to remove the record of unplugged device
  block: Don't check QUEUE_FLAG_SAME_COMP in __blk_complete_request
  mm: Add comment explaining task state setting in bdi_forker_thread()
  mm: Cleanup clearing of BDI_pending bit in bdi_forker_thread()
  block: simplify force plug flush code a little bit
  block: change force plug flush call order
  block: Fix queue_flag update when rq_affinity goes from 2 to 1
  block: separate priority boosting from REQ_META
  block: remove READ_META and WRITE_META
  xen-blkback: fixed indentation and comments
  xen-blkback: Don't disconnect backend until state switched to XenbusStateClosed.
2011-09-21 13:20:21 -07:00
Dave Hansen
32ef43848f teach /proc/$pid/numa_maps about transparent hugepages
This is modeled after the smaps code.

It detects transparent hugepages and then does a single gather_stats()
for the page as a whole.  This has two benifits:
 1. It is more efficient since it does many pages in a single shot.
 2. It does not have to break down the huge page.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-21 13:15:44 -07:00
Dave Hansen
3200a8aaab break out numa_maps gather_pte_stats() checks
gather_pte_stats() does a number of checks on a target page
to see whether it should even be considered for statistics.
This breaks that code out in to a separate function so that
we can use it in the transparent hugepage case in the next
patch.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Christoph Lameter <cl@gentwo.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-21 13:15:44 -07:00
Dave Hansen
eb4866d006 make /proc/$pid/numa_maps gather_stats() take variable page size
We need to teach the numa_maps code about transparent huge pages.  The
first step is to teach gather_stats() that the pte it is dealing with
might represent more than one page.

Note that will we use this in a moment for transparent huge pages since
they have use a single pmd_t which _acts_ as a "surrogate" for a bunch
of smaller pte_t's.

I'm a _bit_ unhappy that this interface counts in hugetlbfs page sizes
for hugetlbfs pages and PAGE_SIZE for normal pages.  That means that to
figure out how many _bytes_ "dirty=1" means, you must first know the
hugetlbfs page size.  That's easier said than done especially if you
don't have visibility in to the mount.

But, that's probably a discussion for another day especially since it
would change behavior to fix it.  But, just in case anyone wonders why
this patch only passes a '1' in the hugetlb case...

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-21 13:15:44 -07:00