For symlinks generic_readlink() will work just fine and for directories
we don't want ->readlink() at all.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

I do not know if you've looked on the patch, but unfortunately it is
incorrect. A suggested better version is in this email (the old
version didn't work in case the user provided buffer was not long
enough - it incorrectly appended null byte on a position of last char,
and thus broke the contract of the readlink method). However, I'm
still not sure this is 100% correct thing to do, I think readlink is
supposed to return buffer without last null byte in all cases, but we
do return last null byte (even the old version).. on the other hand it
is likely unspecified what is in the remaining part of the buffer, so
null character may be fine there ;):
Signed-off-by: NMartin Stava <martin.stava@gmail.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

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

Change all occurrence of inode->i_size with i_size_read() or i_size_write()
as appropriate.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Cast the error return value (ENOMEM) in v9fs_get_inode() to its
correct type using ERR_PTR.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Add missing p9stat_free in v9fs_inode_from_fid to avoid
any possible leaks.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Fix the comments -- mostly the improper and/or missing descriptions
of function parameters.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Add a missing iput when cleaning up if v9fs_get_inode
fails after returning a valid inode.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Check if v9fs_fid_add was successful or not based on its
return value.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

d_iname is rubbish for long file names.
Use d_name.name in printks instead.
Signed-off-by: NWu Fengguang <wfg@linux.intel.com>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

Signed-off-by: NDuane Griffin <duaneg@dghda.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NJames Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Reviewed-by: NEric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: v9fs-developer@lists.sourceforge.net
Signed-off-by: NJames Morris <jmorris@namei.org>

In v9fs_get_inode(), for block, as well as char devices (in theory), 
the function init_special_inode() is called to set up callback functions 
for file ops. this function uses the file mode's value to determine whether 
to use block or char dev functions. In v9fs_inode_from_fid(), the function 
p9mode2unixmode() is used, but for all devices it initially returns S_IFBLK, 
then uses v9fs_get_inode() to initialise a new inode, then finally uses 
v9fs_stat2inode(), which would determine whether the inode is a block or 
character device. However, at that point init_special_inode() had already 
decided to use the block device functions, so even if the inode's mode is 
turned to a character device, the block functions are still used to operate 
on them. The attached patch simply calls init_special_inode() again for devices 
after parsing device node data in v9fs_stat2inode() so that the proper functions 
are used.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Now that the new protocol functions are in place, this patch switches
the client code to using the new support code.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

In case of error, the function p9_client_walk returns an ERR pointer, but
never returns a NULL pointer.  So a NULL test that comes after an IS_ERR
test should be deleted.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@match_bad_null_test@
expression x, E;
statement S1,S2;
@@
x = p9_client_walk(...)
... when != x = E
*  if (x != NULL)
S1 else S2
// </smpl>
Signed-off-by: NJulien Brunel <brunel@diku.dk>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

The legacy protocol's open operation doesn't handle an append operation
(it is expected that the client take care of it).  We were incorrectly
passing the extended protocol's flag through even in legacy mode.  This
was reported in bugzilla report #10689.  This patch fixes the problem
by disallowing extended protocol open modes from being passed in legacy
mode and implemented append functionality on the client side by adding
a seek after the open.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

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: NEric Van Hensbergen <ericvh@gmail.com>

Convert instances of ERR_PTR(PTR_ERR(p)) to ERR_CAST(p) using:

perl -spi -e 's/ERR_PTR[(]PTR_ERR[(](.*)[)][)]/ERR_CAST(\1)/' `grep -rl 'ERR_PTR[(]*PTR_ERR' fs crypto net security`
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NAnthony Liguori <aliguori@us.ibm.com>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>

In v9fs_vfs_rename function labels don't match the fids that are clunked.
The correct clunk order is clunking newdirfid first and then olddirfid next.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

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

Change the names of 'uid' and 'gid' parameters to the more appropriate
'dfltuid' and 'dfltgid'.  This also sets the default uid/gid to -2
(aka nfsnobody)
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Create more general flags field in the v9fs_session_info struct and move the
'extended' flag as a bit in the flags.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

This patch expands the impact of the loose cache mode to allow for cached
metadata increasing the performance of directory listings and other metadata
read operations.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

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

First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
   getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
   they don't need sched.h
b) sched.h stops being dependency for significant number of files:
   on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
   after patch it's only 3744 (-8.3%).

Cross-compile tested on

	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
	alpha alpha-up
	arm
	i386 i386-up i386-defconfig i386-allnoconfig
	ia64 ia64-up
	m68k
	mips
	parisc parisc-up
	powerpc powerpc-up
	s390 s390-up
	sparc sparc-up
	sparc64 sparc64-up
	um-x86_64
	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

v9fs_insert uses v9fs_fid_lookup (which also locks the fid) to get the
primary fid associated with the dentry and destroys the v9fs_fid struct
after removing the file.  If another process called v9fs_fid_lookup on the
same dentry, it may wait undefinitely for the fid's lock (as the struct is
freed).

This patch changes v9fs_remove to use a cloned fid, so the primary fid is
not locked and freed.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@hera.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

While cacheing is generally frowned upon in the 9p world, it has its
place -- particularly in situations where the remote file system is
exclusive and/or read-only.  The vacfs views of venti content addressable
store are a real-world instance of such a situation.  To facilitate higher
performance for these workloads (and eventually use the fscache patches),
we have enabled a "loose" cache mode which does not attempt to maintain
any form of consistency on the page-cache or dcache.  This results in over
two orders of magnitude performance improvement for cacheable block reads
in the Bonnie benchmark.  The more aggressive use of the dcache also seems
to improve metadata operational performance.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a double free of "dfid" introduced by commit
da977b2c and spotted by the Coverity
checker.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Running dbench multithreaded exposed a race condition where fid structures
were removed while in use.  This patch adds semaphores to meta-data operations
to protect the fid structure.  Some cleanup of error-case handling in the
inode operations is also included.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

9p doesn't handle renames between directories -- however, we were returning
EPERM instead of EXDEV when we detected this case.
Signed-off-by: NEric Van Hensbergren <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Function v9fs_get_idpool returns int, not u32.  Actually it returns -1 on
errors, and these two callers check if the value is smaller than 0, which
was caught by gcc with extra warning flags.  Compile tested only but should
be OK, as the value computed in v9fs_get_idpool() is also int.
Signed-of-by: NMika Kukkonen <mikukkon@iki.fi>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@lanl.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is mostly included for parity with dec_nlink(), where we will have some
more hooks.  This one should stay pretty darn straightforward for now.
Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This eliminates the i_blksize field from struct inode.  Filesystems that want
to provide a per-inode st_blksize can do so by providing their own getattr
routine instead of using the generic_fillattr() function.

Note that some filesystems were providing pretty much random (and incorrect)
values for i_blksize.

[bunk@stusta.de: cleanup]
[akpm@osdl.org: generic_fillattr() fix]
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Based on a bug report from Russ Ross <russruss@gmail.com>

According to the spec:

"The remove request asks the file server both to remove the file
 represented by fid and to clunk the fid, even if the remove fails."

but the Linux client seems to expect the fid to be valid after a failed
remove attempt.  Specifically, I'm getting this behavior when attempting to
remove a non-empty directory.
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix an incorrect check whether a fid was allocated in v9fs_create and if it
should be freed on error.
Signed-off-by: NLatchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

coverity found two needless checks in vfs_inode.c (cid #1165 and #1164)
In both cases inode is always NULL when we goto error; either because it
is still initialized to NULL or is set to NULL explicitly. This patch
simply removes these checks to save some code.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@lanl.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

__getname() may fail and return NULL (as pointed out by Coverity 437 &
1220).
Signed-off-by: NFlorin Malita <fmalita@gmail.com>
Acked-by: NEric Van Hensbergen <ericvh@gmail.com>
Cc: <rminnich@lanl.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>