9p: Add additional debug flags and open modes

Add some additional debug flags to assist with debugging
cache changes. Also add some additional open modes so we
can track cache state in fids more directly.

Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>

net/9p: distinguish zero-copy requests

Add boolean `zc` member to struct p9_fcall to distinguish zero-copy
messages (not using the linear `sdata` buffer for message payload) from
regular messages (which do copy message payload to `sdata` before being
further processed).

This new member is appended to end of structure to avoid inserting huge
padding in generated layout.

Link: https://lkml.kernel.org/r/8f2a5c12a446c3b544da64e0b1550e1fb2d6f972.1669144861.git.linux_oss@crudebyte.com
Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

9p: add P9_ERRMAX for 9p2000 and 9p2000.u

Add P9_ERRMAX macro to 9P protocol header which reflects the maximum
error string length of Rerror replies for 9p2000 and 9p2000.u protocol
versions. Unfortunately a maximum error string length is not defined by
the 9p2000 spec, picking 128 as value for now, as this seems to be a
common max. size for POSIX error strings in practice.

9p2000.L protocol version uses Rlerror replies instead which does not
contain an error string.

Link: https://lkml.kernel.org/r/3f23191d21032e7c14852b1e1a4ae26417a36739.1657920926.git.linux_oss@crudebyte.com
Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

9p/trans_fd: split into dedicated module

This allows these transports only to be used when needed.

Link: https://lkml.kernel.org/r/20211103193823.111007-3-linux@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
[Dominique: Kconfig NET_9P_FD: -depends VIRTIO, +default NET_9P]
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

9p: fix a bunch of checkpatch warnings

Sohaib Mohamed started a serie of tiny and incomplete checkpatch fixes but
seemingly stopped halfway -- take over and do most of it.
This is still missing net/9p/trans* and net/9p/protocol.c for a later
time...

Link: http://lkml.kernel.org/r/20211102134608.1588018-3-dominique.martinet@atmark-techno.com
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

9p: fix file headers

- add missing SPDX-License-Identifier
- remove (sometimes incorrect) file name from file header

Link: http://lkml.kernel.org/r/20211102134608.1588018-2-dominique.martinet@atmark-techno.com
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to free software
foundation 51 franklin street fifth floor boston ma 02111 1301 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 27 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.981318839@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

9p: add a per-client fcall kmem_cache

Having a specific cache for the fcall allocations helps speed up
end-to-end latency.

The caches will automatically be merged if there are multiple caches
of items with the same size so we do not need to try to share a cache
between different clients of the same size.

Since the msize is negotiated with the server, only allocate the cache
after that negotiation has happened - previous allocations or
allocations of different sizes (e.g. zero-copy fcall) are made with
kmalloc directly.

Some figures on two beefy VMs with Connect-IB (sriov) / trans=rdma,
with ior running 32 processes in parallel doing small 32 bytes IOs:
- no alloc (4.18-rc7 request cache): 65.4k req/s
- non-power of two alloc, no patch: 61.6k req/s
- power of two alloc, no patch: 62.2k req/s
- non-power of two alloc, with patch: 64.7k req/s
- power of two alloc, with patch: 65.1k req/s

Link: http://lkml.kernel.org/r/1532943263-24378-2-git-send-email-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Acked-by: Jun Piao <piaojun@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Greg Kurz <groug@kaod.org>

9p: Remove p9_idpool

There are no more users left of the p9_idpool; delete it.

Link: http://lkml.kernel.org/r/20180711210225.19730-7-willy@infradead.org
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>

9p: constify ->d_name handling

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

9p: Modify the stat structures to use kuid_t and kgid_t

9p has thre strucrtures that can encode inode stat information. Modify
all of those structures to contain kuid_t and kgid_t values. Modify
he wire encoders and decoders of those structures to use 'u' and 'g' instead of
'd' in the format string where uids and gids are present.

This results in all kuid and kgid conversion to and from on the wire values
being performed by the same code in protocol.c where the client is known
at the time of the conversion.

Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

9p: Reduce object size with CONFIG_NET_9P_DEBUG

Reduce object size by deduplicating formats.

Use vsprintf extension %pV.
Rename P9_DPRINTK uses to p9_debug, align arguments.
Add function for _p9_debug and macro to add __func__.
Add missing "\n"s to p9_debug uses.
Remove embedded function names as p9_debug adds it.
Remove P9_EPRINTK macro and convert use to pr_<level>.
Add and use pr_fmt and pr_<level>.

$ size fs/9p/built-in.o*
text data bss dec hex filename
62133 984 16000 79117 1350d fs/9p/built-in.o.new
67342 984 16928 85254 14d06 fs/9p/built-in.o.old
$ size net/9p/built-in.o*
text data bss dec hex filename
88792 4148 22024 114964 1c114 net/9p/built-in.o.new
94072 4148 23232 121452 1da6c net/9p/built-in.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

net/9p: Convert net/9p protocol dumps to tracepoints

This helps in more control over debugging.
root@qemu-img-64:~# ls /pass/123
ls: cannot access /pass/123: No such file or directory
root@qemu-img-64:~# cat /sys/kernel/debug/tracing/trace
# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
ls-1536 [001] 70.928584: 9p_protocol_dump: clnt 18446612132784021504 P9_TWALK(tag = 1)
000: 16 00 00 00 6e 01 00 01 00 00 00 02 00 00 00 01
010: 00 03 00 31 32 33 00 00 00 ff ff ff ff 00 00 00

ls-1536 [001] 70.928587: <stack trace>
=> trace_9p_protocol_dump
=> p9pdu_finalize
=> p9_client_rpc
=> p9_client_walk
=> v9fs_vfs_lookup
=> d_alloc_and_lookup
=> walk_component
=> path_lookupat
ls-1536 [000] 70.929696: 9p_protocol_dump: clnt 18446612132784021504 P9_RLERROR(tag = 1)
000: 0b 00 00 00 07 01 00 02 00 00 00 4e 03 00 02 00
010: 00 00 00 00 03 00 02 00 00 00 00 00 ff 43 00 00

ls-1536 [000] 70.929697: <stack trace>
=> trace_9p_protocol_dump
=> p9_client_rpc
=> p9_client_walk
=> v9fs_vfs_lookup
=> d_alloc_and_lookup
=> walk_component
=> path_lookupat
=> do_path_lookup

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

fs/9p: Update zero-copy implementation in 9p

* remove lot of update to different data structure
* add a seperate callback for zero copy request.
* above makes non zero copy code path simpler
* remove conditionalizing TREAD/TREADDIR/TWRITE in the zero copy path
* Fix the dotu p9_check_errors with zero copy. Add sufficient doc around
* Add support for both in and output buffers in zero copy callback
* pin and unpin pages in the same context
* use helpers instead of defining page offset and rest of page ourself
* Fix mem leak in p9_check_errors
* Remove 'E' and 'F' in p9pdu_vwritef

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

fs/9p: Use protocol-defined value for lock/getlock 'type' field.

Signed-off-by: Jim Garlick <garlick@llnl.gov>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

fs/9p: Add OS dependent open flags in 9p protocol

Some of the flags are OS/arch dependent we add a 9p
protocol value which maps to asm-generic/fcntl.h values in Linux
Based on the original patch from Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

fs/9p: add 9P2000.L unlinkat operation

unlinkat - Remove a directory entry

size[4] Tunlinkat tag[2] dirfid[4] name[s] flag[4]
size[4] Runlinkat tag[2]

older Tremove have the below request format

size[4] Tremove tag[2] fid[4]

The remove message is used to remove a directory entry either file or directory
The remove opreation is actually a directory opertation and should ideally have
dirfid, if not we cannot represent the fid on server with anything other than
name. We will have to derive the directory name from fid in the Tremove request.

NOTE: The operation doesn't clunk the unlink fid.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

fs/9p: add 9P2000.L renameat operation

renameat - change name of file or directory

size[4] Trenameat tag[2] olddirfid[4] oldname[s] newdirfid[4] newname[s]
size[4] Rrenameat tag[2]

older Trename have the below request format

size[4] Trename tag[2] fid[4] newdirfid[4] name[s]

The rename message is used to change the name of a file, possibly moving it
to a new directory. The rename opreation is actually a directory opertation
and should ideally have olddirfid, if not we cannot represent the fid on server
with anything other than name. We will have to derive the old directory name
from fid in the Trename request.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

net/9p: Remove structure not used in the code

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: clean up packet dump code

Switch to generic kernel hexdump library and cleanup macros to
be more consistent with the way we do normal debug prints.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Small cleanup in <net/9p/9p.h>

There are two small cleanups in this patch:
- p9_errstr2errno was declared twice - remove one declaration.
- A uint8_t type was mixed in, change it to u8 to match
with the rest of the type names and remove dependency.

Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: typo fixes and minor cleanups

Typo fixes and minor cleanups for v9fs

Signed-off-by: Rob Landley <rob@landley.net>
Reviewed-by: Venkateswararao Jujjuri (JV) <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: revert tsyncfs related changes

Now that we use write_inode to flush server
cache related to fid, we don't need tsyncfs either fort dotl or dotu
protocols. For dotu this helps to do a more efficient server flush.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

net/9p: Implement syncfs 9P operation

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

[net/9p] Small non-IO PDUs for zero-copy supporting transports.

If a transport prefers payload to be sent separate from the PDU
(P9_TRANS_PREF_PAYLOAD_SEP), there is no need to allocate msize
PDU buffers(struct p9_fcall).

This patch allocates only upto 4k buffers for this kind of transports
and there won't be any change to the legacy transports.

Hence, this patch on top of zero copy changes allows user to
specify higher msizes through the mount option
without hogging the kernel heap.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

[net/9p] Preparation and helper functions for zero copy

This patch prepares p9_fcall structure for zero copy. Added
fields send the payload buffer information to the transport layer.
In addition it adds a 'private' field for the transport layer to
store mapped/pinned page information so that it can be freed/unpinned
during req_done.

This patch also creates trans_common.[ch] to house helper functions.
It adds the following helper functions.

p9_release_req_pages - Release pages after the transaction.
p9_nr_pages - Return number of pages needed to accomodate the payload.
payload_gup - Translates user buffer into kernel pages.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Implement TREADLINK operation for 9p2000.L

Synopsis

size[4] TReadlink tag[2] fid[4]
size[4] RReadlink tag[2] target[s]

Description
Readlink is used to return the contents of the symoblic link
referred by fid. Contents of symboic link is returned as a
response.

target[s] - Contents of the symbolic link referred by fid.

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Implement TGETLOCK

Synopsis

size[4] TGetlock tag[2] fid[4] getlock[n]
size[4] RGetlock tag[2] getlock[n]

Description

TGetlock is used to test for the existence of byte range posix locks on a file
identified by given fid. The reply contains getlock structure. If the lock could
be placed it returns F_UNLCK in type field of getlock structure. Otherwise it
returns the details of the conflicting locks in the getlock structure

getlock structure:
type[1] - Type of lock: F_RDLCK, F_WRLCK
start[8] - Starting offset for lock
length[8] - Number of bytes to check for the lock
If length is 0, check for lock in all bytes starting at the location
'start' through to the end of file
pid[4] - PID of the process that wants to take lock/owns the task
in case of reply
client[4] - Client id of the system that owns the process which
has the conflicting lock

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Implement TLOCK

Synopsis

size[4] TLock tag[2] fid[4] flock[n]
size[4] RLock tag[2] status[1]

Description

Tlock is used to acquire/release byte range posix locks on a file
identified by given fid. The reply contains status of the lock request

flock structure:
type[1] - Type of lock: F_RDLCK, F_WRLCK, F_UNLCK
flags[4] - Flags could be either of
P9_LOCK_FLAGS_BLOCK - Blocked lock request, if there is a
conflicting lock exists, wait for that lock to be released.
P9_LOCK_FLAGS_RECLAIM - Reclaim lock request, used when client is
trying to reclaim a lock after a server restrart (due to crash)
start[8] - Starting offset for lock
length[8] - Number of bytes to lock
If length is 0, lock all bytes starting at the location 'start'
through to the end of file
pid[4] - PID of the process that wants to take lock
client_id[4] - Unique client id

status[1] - Status of the lock request, can be
P9_LOCK_SUCCESS(0), P9_LOCK_BLOCKED(1), P9_LOCK_ERROR(2) or
P9_LOCK_GRACE(3)
P9_LOCK_SUCCESS - Request was successful
P9_LOCK_BLOCKED - A conflicting lock is held by another process
P9_LOCK_ERROR - Error while processing the lock request
P9_LOCK_GRACE - Server is in grace period, it can't accept new lock
requests in this period (except locks with
P9_LOCK_FLAGS_RECLAIM flag set)

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

[9p] Introduce client side TFSYNC/RFSYNC for dotl.

SYNOPSIS
size[4] Tfsync tag[2] fid[4]

size[4] Rfsync tag[2]

DESCRIPTION

The Tfsync transaction transfers ("flushes") all modified in-core data of
file identified by fid to the disk device (or other permanent storage
device) where that file resides.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

net/9p: This patch implements TLERROR/RLERROR on the 9P client.

Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

net/9p: Implement TXATTRCREATE 9p call

TXATTRCREATE: Prepare a fid for setting xattr value on a file system object.

size[4] TXATTRCREATE tag[2] fid[4] name[s] attr_size[8] flags[4]
size[4] RXATTRCREATE tag[2]

txattrcreate gets a fid pointing to xattr. This fid can later be
used to set the xattr value.

flag value is derived from set Linux setxattr. The manpage says
"The flags parameter can be used to refine the semantics of the operation.
XATTR_CREATE specifies a pure create, which fails if the named attribute
exists already. XATTR_REPLACE specifies a pure replace operation, which
fails if the named attribute does not already exist. By default (no flags),
the extended attribute will be created if need be, or will simply replace
the value if the attribute exists."

The actual setxattr operation happens when the fid is clunked. At that point
the written byte count and the attr_size specified in TXATTRCREATE should be
same otherwise an error will be returned.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

net/9p: Implement attrwalk 9p call

TXATTRWALK: Descend a ATTR namespace

size[4] TXATTRWALK tag[2] fid[4] newfid[4] name[s]
size[4] RXATTRWALK tag[2] size[8]

txattrwalk gets a fid pointing to xattr. This fid can later be
used to read the xattr value. If name is NULL the fid returned
can be used to get the list of extended attribute associated to
the file system object.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Implement LOPEN

Implement 9p2000.L version of open(LOPEN) interface in 9p client.

For LOPEN, no need to convert the flags to and from 9p mode to VFS mode.

Synopsis:

size[4] Tlopen tag[2] fid[4] mode[4]

size[4] Rlopen tag[2] qid[13] iounit[4]

[Fix mode bit format - jvrao@linux.vnet.ibm.com]

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbegren <ericvh@gmail.com>

fs/9p: This patch implements TLCREATE for 9p2000.L protocol.

SYNOPSIS

size[4] Tlcreate tag[2] fid[4] name[s] flags[4] mode[4] gid[4]

size[4] Rlcreate tag[2] qid[13] iounit[4]

DESCRIPTION

The Tlreate request asks the file server to create a new regular file with the
name supplied, in the directory (dir) represented by fid.
The mode argument specifies the permissions to use. New file is created with
the uid if the fid and with supplied gid.

The flags argument represent Linux access mode flags with which the caller
is requesting to open the file with. Protocol allows all the Linux access
modes but it is upto the server to allow/disallow any of these acess modes.
If the server doesn't support any of the access mode, it is expected to
return error.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Implement TMKDIR

Implement TMKDIR as part of 2000.L Work

Synopsis

size[4] Tmkdir tag[2] fid[4] name[s] mode[4] gid[4]

size[4] Rmkdir tag[2] qid[13]

Description

mkdir asks the file server to create a directory with given name,
mode and gid. The qid for the new directory is returned with
the mkdir reply message.

Note: 72 is selected as the opcode for TMKDIR from the reserved list.

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Implement TMKNOD

Synopsis

size[4] Tmknod tag[2] fid[4] name[s] mode[4] major[4] minor[4] gid[4]

size[4] Rmknod tag[2] qid[13]

Description

mknod asks the file server to create a device node with given major and
minor number, mode and gid. The qid for the new device node is returned
with the mknod reply message.

[sripathik@in.ibm.com: Fix error handling code]

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Define and implement TSYMLINK for 9P2000.L

Create a symbolic link

SYNOPSIS

size[4] Tsymlink tag[2] fid[4] name[s] symtgt[s] gid[4]

size[4] Rsymlink tag[2] qid[13]

DESCRIPTION

Create a symbolic link named 'name' pointing to 'symtgt'.
gid represents the effective group id of the caller.
The permissions of a symbolic link are irrelevant hence it is omitted
from the protocol.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Reviewed-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Define and implement TLINK for 9P2000.L

This patch adds a helper function to get the dentry from inode and
uses it in creating a Hardlink

SYNOPSIS

size[4] Tlink tag[2] dfid[4] oldfid[4] newpath[s]

size[4] Rlink tag[2]

DESCRIPTION

Create a link 'newpath' in directory pointed by dfid linking to oldfid path.

[sripathik@in.ibm.com : p9_client_link should not free req structure
if p9_client_rpc has returned an error.]

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Implement client side of setattr for 9P2000.L protocol.

SYNOPSIS

size[4] Tsetattr tag[2] attr[n]

size[4] Rsetattr tag[2]

DESCRIPTION

The setattr command changes some of the file status information.
attr resembles the iattr structure used in Linux kernel. It
specifies which status parameter is to be changed and to what
value. It is laid out as follows:

valid[4]
specifies which status information is to be changed. Possible
values are:
ATTR_MODE (1 << 0)
ATTR_UID (1 << 1)
ATTR_GID (1 << 2)
ATTR_SIZE (1 << 3)
ATTR_ATIME (1 << 4)
ATTR_MTIME (1 << 5)
ATTR_ATIME_SET (1 << 7)
ATTR_MTIME_SET (1 << 8)

The last two bits represent whether the time information
is being sent by the client's user space. In the absense
of these bits the server always uses server's time.

mode[4]
File permission bits

uid[4]
Owner id of file

gid[4]
Group id of the file

size[8]
File size

atime_sec[8]
Time of last file access, seconds

atime_nsec[8]
Time of last file access, nanoseconds

mtime_sec[8]
Time of last file modification, seconds

mtime_nsec[8]
Time of last file modification, nanoseconds

Explanation of the patches:
--------------------------

*) The kernel just copies relevent contents of iattr structure to
p9_iattr_dotl structure and passes it down to the client. The
only check it has is calling inode_change_ok()
*) The p9_iattr_dotl structure does not have ctime and ia_file
parameters because I don't think these are needed in our case.
The client user space can request updating just ctime by calling
chown(fd, -1, -1). This is handled on server side without a need
for putting ctime on the wire.
*) The server currently supports changing mode, time, ownership and
size of the file.
*) 9P RFC says "Either all the changes in wstat request happen, or
none of them does: if the request succeeds, all changes were made;
if it fails, none were."
I have not done anything to implement this specifically because I
don't see a reason.

Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: getattr client implementation for 9P2000.L protocol.

SYNOPSIS

size[4] Tgetattr tag[2] fid[4] request_mask[8]

size[4] Rgetattr tag[2] lstat[n]

DESCRIPTION

The getattr transaction inquires about the file identified by fid.
request_mask is a bit mask that specifies which fields of the
stat structure is the client interested in.

The reply will contain a machine-independent directory entry,
laid out as follows:

st_result_mask[8]
Bit mask that indicates which fields in the stat structure
have been populated by the server

qid.type[1]
the type of the file (directory, etc.), represented as a bit
vector corresponding to the high 8 bits of the file's mode
word.

qid.vers[4]
version number for given path

qid.path[8]
the file server's unique identification for the file

st_mode[4]
Permission and flags

st_uid[4]
User id of owner

st_gid[4]
Group ID of owner

st_nlink[8]
Number of hard links

st_rdev[8]
Device ID (if special file)

st_size[8]
Size, in bytes

st_blksize[8]
Block size for file system IO

st_blocks[8]
Number of file system blocks allocated

st_atime_sec[8]
Time of last access, seconds

st_atime_nsec[8]
Time of last access, nanoseconds

st_mtime_sec[8]
Time of last modification, seconds

st_mtime_nsec[8]
Time of last modification, nanoseconds

st_ctime_sec[8]
Time of last status change, seconds

st_ctime_nsec[8]
Time of last status change, nanoseconds

st_btime_sec[8]
Time of creation (birth) of file, seconds

st_btime_nsec[8]
Time of creation (birth) of file, nanoseconds

st_gen[8]
Inode generation

st_data_version[8]
Data version number

request_mask and result_mask bit masks contain the following bits
#define P9_STATS_MODE 0x00000001ULL
#define P9_STATS_NLINK 0x00000002ULL
#define P9_STATS_UID 0x00000004ULL
#define P9_STATS_GID 0x00000008ULL
#define P9_STATS_RDEV 0x00000010ULL
#define P9_STATS_ATIME 0x00000020ULL
#define P9_STATS_MTIME 0x00000040ULL
#define P9_STATS_CTIME 0x00000080ULL
#define P9_STATS_INO 0x00000100ULL
#define P9_STATS_SIZE 0x00000200ULL
#define P9_STATS_BLOCKS 0x00000400ULL

#define P9_STATS_BTIME 0x00000800ULL
#define P9_STATS_GEN 0x00001000ULL
#define P9_STATS_DATA_VERSION 0x00002000ULL

#define P9_STATS_BASIC 0x000007ffULL
#define P9_STATS_ALL 0x00003fffULL

This patch implements the client side of getattr implementation for
9P2000.L. It introduces a new structure p9_stat_dotl for getting
Linux stat information along with QID. The data layout is similar to
stat structure in Linux user space with the following major
differences:

inode (st_ino) is not part of data. Instead qid is.

device (st_dev) is not part of data because this doesn't make sense
on the client.

All time variables are 64 bit wide on the wire. The kernel seems to use
32 bit variables for these variables. However, some of the architectures
have used 64 bit variables and glibc exposes 64 bit variables to user
space on some architectures. Hence to be on the safer side we have made
these 64 bit in the protocol. Refer to the comments in
include/asm-generic/stat.h

There are some additional fields: st_btime_sec, st_btime_nsec, st_gen,
st_data_version apart from the bitmask, st_result_mask. The bit mask
is filled by the server to indicate which stat fields have been
populated by the server. Currently there is no clean way for the
server to obtain these additional fields, so it sends back just the
basic fields.

Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbegren <ericvh@gmail.com>

9p: readdir implementation for 9p2000.L

This patch implements the kernel part of readdir() implementation for 9p2000.L

Change from V3: Instead of inode, server now sends qids for each dirent

SYNOPSIS

size[4] Treaddir tag[2] fid[4] offset[8] count[4]
size[4] Rreaddir tag[2] count[4] data[count]

DESCRIPTION

The readdir request asks the server to read the directory specified by 'fid'
at an offset specified by 'offset' and return as many dirent structures as
possible that fit into count bytes. Each dirent structure is laid out as
follows.

qid.type[1]
the type of the file (directory, etc.), represented as a bit
vector corresponding to the high 8 bits of the file's mode
word.

qid.vers[4]
version number for given path

qid.path[8]
the file server's unique identification for the file

offset[8]
offset into the next dirent.

type[1]
type of this directory entry.

name[256]
name of this directory entry.

This patch adds v9fs_dir_readdir_dotl() as the readdir() call for 9p2000.L.
This function sends P9_TREADDIR command to the server. In response the server
sends a buffer filled with dirent structures. This is different from the
existing v9fs_dir_readdir() call which receives stat structures from the server.
This results in significant speedup of readdir() on large directories.
For example, doing 'ls >/dev/null' on a directory with 10000 files on my
laptop takes 1.088 seconds with the existing code, but only takes 0.339 seconds
with the new readdir.

Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: add 9P2000.L rename operation

I made a V2 of this patch on top of my patches for VFS switches.
All the changes were due to change in some offsets.

rename - change name of file or directory

size[4] Trename tag[2] fid[4] newdirfid[4] name[s]
size[4] Rrename tag[2]

The rename message is used to change the name of a file, possibly moving it
to a new directory. The 9P wstat message can only rename a file within the
same directory.

Signed-off-by: Jim Garlick <garlick@llnl.gov>
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: add 9P2000.L statfs operation

I made a V2 of this patch on top of my patches for VFS switches. The
change was adding v9fs_statfs pointer to v9fs_super_ops_dotl
instead of v9fs_super_ops.

statfs - get file system statistics

size[4] Tstatfs tag[2] fid[4]
size[4] Rstatfs tag[2] type[4] bsize[4] blocks[8] bfree[8] bavail[8]
files[8] ffree[8] fsid[8] namelen[4]

The statfs message is used to request file system information returned
by the statfs(2) system call, which is used by df(1) to report file
system and disk space usage.

Signed-off-by: Jim Garlick <garlick@llnl.gov>
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Add fscache support to 9p

This patch adds a persistent, read-only caching facility for
9p clients using the FS-Cache caching backend.

When the fscache facility is enabled, each inode is associated
with a corresponding vcookie which is an index into the FS-Cache
indexing tree. The FS-Cache indexing tree is indexed at 3 levels:
- session object associated with each mount.
- inode/vcookie
- actual data (pages)

A cache tag is chosen randomly for each session. These tags can
be read off /sys/fs/9p/caches and can be passed as a mount-time
parameter to re-attach to the specified caching session.

Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: fix debug build error

Fixes build problem with 9p when building with debug disabled.
Also contains some fixes for warnings which pop up when
CONFIG_NET_9P_DEBUG is disabled.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Improve debug support

The new debug support lacks some of the information that the previous fcprint
code provided -- this patch focuses on better presentation of debug data along
with more helpful debug along error paths.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: eliminate depricated conv functions

Remove depricated conv functions which have been replaced with new
protocol routines.

This patch also reworks the one instance of the file-system code which
directly calls conversion routines (to accomplish unpacking dirreads).

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: rework client code to use new protocol support functions

Now that the new protocol functions are in place, this patch switches
the client code to using the new support code.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: remove 9p fcall debug prints

One of the current debug options allows users to get a verbose dump of fcalls.
This isn't really necessary as correctly parsed protocol frames can be printed
as part of the code in the client functions. The consolidated printfcalls
structure would require new entries to be added for every extension. This
patch removes the debug print methods and their use.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: add new protocol support code

This adds a new protocol processing support code based on Anthony Liguori's
9p library code. This code performs protocol marshalling/unmarshalling using
printf like strings to represent protocol elements. It is my intent to use
them to replace the current functions in conv.c as well as the
p9_create_* functions.

This should make the client implementation much more clear, and also make it
much easier to add new protocol extensions by limiting the number of places
in which changes need to be made.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

include: replace __FUNCTION__ with __func__

__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9p: implement proper trans module refcounting and unregistration

9p trans modules aren't refcounted nor were they unregistered
properly. Fix it.

* Add 9p_trans_module->owner and reference the module on each trans
instance creation and put it on destruction.

* Protect v9fs_trans_list with a spinlock. This isn't strictly
necessary as the list is manipulated only during module loading /
unloading but it's a good idea to make the API safe.

* Unregister trans modules when the corresponding module is being
unloaded.

* While at it, kill unnecessary EXPORT_SYMBOL on p9_trans_fd_init().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: fix error path during early mount

There was some cleanup issues during early mount which would trigger
a kernel bug for certain types of failure. This patch reorganizes the
cleanup to get rid of the bad behavior.

This also merges the 9pnet and 9pnet_fd modules for the purpose of
configuration and initialization. Keeping the fd transport separate
from the core 9pnet code seemed like a good idea at the time, but in
practice has caused more harm and confusion than good.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: Documentation updates

The kernel-doc comments of much of the 9p system have been in disarray since
reorganization. This patch fixes those problems, adds additional documentation
and a template book which collects the 9p information.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: add support for sticky bit

GDM gets unhappy if /var/gdm doesn't have the sticky bit set. This patch adds
support for the sticky bit in much the same way setuid/setgid is supported.

With this patch, I can launch X from a v9fs rootfs (although I quickly run out
of fds in the server once gnome starts up).

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Acked-by: Eric Van Hensbergen <ericvh@gmail.com>

Use helpers to obtain task pid in printks

The task_struct->pid member is going to be deprecated, so start
using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in
the kernel.

The first thing to start with is the pid, printed to dmesg - in
this case we may safely use task_pid_nr(). Besides, printks produce
more (much more) than a half of all the explicit pid usage.

[akpm@linux-foundation.org: git-drm went and changed lots of stuff]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

9p: remove sysctl

A sysctl method was added to enable and disable debugging levels. After
further review, it was decided that there are better approaches to doing this
and the sysctl methodology isn't really desirable. This patch removes the
sysctl code from 9p.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

9p: attach-per-user

The 9P2000 protocol requires the authentication and permission checks to be
done in the file server. For that reason every user that accesses the file
server tree has to authenticate and attach to the server separately.
Multiple users can share the same connection to the server.

Currently v9fs does a single attach and executes all I/O operations as a
single user. This makes using v9fs in multiuser environment unsafe as it
depends on the client doing the permission checking.

This patch improves the 9P2000 support by allowing every user to attach
separately. The patch defines three modes of access (new mount option
'access'):

- attach-per-user (access=user) (default mode for 9P2000.u)
If a user tries to access a file served by v9fs for the first time, v9fs
sends an attach command to the server (Tattach) specifying the user. If
the attach succeeds, the user can access the v9fs tree.
As there is no uname->uid (string->integer) mapping yet, this mode works
only with the 9P2000.u dialect.

- allow only one user to access the tree (access=<uid>)
Only the user with uid can access the v9fs tree. Other users that attempt
to access it will get EPERM error.

- do all operations as a single user (access=any) (default for 9P2000)
V9fs does a single attach and all operations are done as a single user.
If this mode is selected, the v9fs behavior is identical with the current
one.

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

[9P]: build fix with !CONFIG_SYSCTL

found via make randconfig build testing:

net/built-in.o: In function `init_p9':
mod.c:(.init.text+0x3b39): undefined reference to `p9_sysctl_register'
net/built-in.o: In function `exit_p9':
mod.c:(.exit.text+0x36b): undefined reference to `p9_sysctl_unregister'

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>

9p: Reorganization of 9p file system code

This patchset moves non-filesystem interfaces of v9fs from fs/9p to net/9p.
It moves the transport, packet marshalling and connection layers to net/9p
leaving only the VFS related files in fs/9p. This work is being done in
preparation for in-kernel 9p servers as well as alternate 9p clients (other
than VFS).

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>