In commit 85fe402 (fs: do not assign default i_ino in new_inode), the
initialisation of i_ino was removed from new_inode() and pushed down
into the callers. However spufs_new_inode() was not updated.
This exhibits as no files appearing in /spu, because all our dirents
have a zero inode, which readdir() seems to dislike.
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.
A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.
Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.
Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives. Allowing simple, safe,
well understood work-arounds to known problematic software.
This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work. While writing this patch I saw a handful of such
cases. The most significant being autofs that lives in the module
autofs4.
This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.
After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module. The common pattern in the kernel is to call request_module()
without regards to the users permissions. In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted. In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Pull powerpc merge from Benjamin Herrenschmidt:
"Here's the powerpc batch for this merge window. It is going to be a
bit more nasty than usual as in touching things outside of
arch/powerpc mostly due to the big iSeriesectomy :-) We finally got
rid of the bugger (legacy iSeries support) which was a PITA to
maintain and that nobody really used anymore.
Here are some of the highlights:
- Legacy iSeries is gone. Thanks Stephen ! There's still some bits
and pieces remaining if you do a grep -ir series arch/powerpc but
they are harmless and will be removed in the next few weeks
hopefully.
- The 'fadump' functionality (Firmware Assisted Dump) replaces the
previous (equivalent) "pHyp assisted dump"... it's a rewrite of a
mechanism to get the hypervisor to do crash dumps on pSeries, the
new implementation hopefully being much more reliable. Thanks
Mahesh Salgaonkar.
- The "EEH" code (pSeries PCI error handling & recovery) got a big
spring cleaning, motivated by the need to be able to implement a
new backend for it on top of some new different type of firwmare.
The work isn't complete yet, but a good chunk of the cleanups is
there. Note that this adds a field to struct device_node which is
not very nice and which Grant objects to. I will have a patch soon
that moves that to a powerpc private data structure (hopefully
before rc1) and we'll improve things further later on (hopefully
getting rid of the need for that pointer completely). Thanks Gavin
Shan.
- I dug into our exception & interrupt handling code to improve the
way we do lazy interrupt handling (and make it work properly with
"edge" triggered interrupt sources), and while at it found & fixed
a wagon of issues in those areas, including adding support for page
fault retry & fatal signals on page faults.
- Your usual random batch of small fixes & updates, including a bunch
of new embedded boards, both Freescale and APM based ones, etc..."
I fixed up some conflicts with the generalized irq-domain changes from
Grant Likely, hopefully correctly.
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (141 commits)
powerpc/ps3: Do not adjust the wrapper load address
powerpc: Remove the rest of the legacy iSeries include files
powerpc: Remove the remaining CONFIG_PPC_ISERIES pieces
init: Remove CONFIG_PPC_ISERIES
powerpc: Remove FW_FEATURE ISERIES from arch code
tty/hvc_vio: FW_FEATURE_ISERIES is no longer selectable
powerpc/spufs: Fix double unlocks
powerpc/5200: convert mpc5200 to use of_platform_populate()
powerpc/mpc5200: add options to mpc5200_defconfig
powerpc/mpc52xx: add a4m072 board support
powerpc/mpc5200: update mpc5200_defconfig to fit for charon board
Documentation/powerpc/mpc52xx.txt: Checkpatch cleanup
powerpc/44x: Add additional device support for APM821xx SoC and Bluestone board
powerpc/44x: Add support PCI-E for APM821xx SoC and Bluestone board
MAINTAINERS: Update PowerPC 4xx tree
powerpc/44x: The bug fixed support for APM821xx SoC and Bluestone board
powerpc: document the FSL MPIC message register binding
powerpc: add support for MPIC message register API
powerpc/fsl: Added aliased MSIIR register address to MSI node in dts
powerpc/85xx: mpc8548cds - add 36-bit dts
...
spufs return path has a bug where it could end up trying to
unlock an inode mutex twice. Fix it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else. Not to mention the removal of
boilerplate code from ->destroy_inode() instances...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
dget_locked was a shortcut to avoid the lazy lru manipulation when we already
held dcache_lock (lru manipulation was relatively cheap at that point).
However, how that the lru lock is an innermost one, we never hold it at any
caller, so the lock cost can now be avoided. We already have well working lazy
dcache LRU, so it should be fine to defer LRU manipulations to scan time.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Protect d_unhashed(dentry) condition with d_lock. This means keeping
DCACHE_UNHASHED bit in synch with hash manipulations.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Replace inode_setattr with opencoded variants of it in all callers. This
moves the remaining call to vmtruncate into the filesystem methods where it
can be replaced with the proper truncate sequence.
In a few cases it was obvious that we would never end up calling vmtruncate
so it was left out in the opencoded variant:
spufs: explicitly checks for ATTR_SIZE earlier
btrfs,hugetlbfs,logfs,dlmfs: explicitly clears ATTR_SIZE earlier
ufs: contains an opencoded simple_seattr + truncate that sets the filesize just above
In addition to that ncpfs called inode_setattr with handcrafted iattrs,
which allowed to trim down the opencoded variant.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We don't name our generic fsync implementations very well currently.
The no-op implementation for in-memory filesystems currently is called
simple_sync_file which doesn't make too much sense to start with,
the the generic one for simple filesystems is called simple_fsync
which can lead to some confusion.
This patch renames the generic file fsync method to generic_file_fsync
to match the other generic_file_* routines it is supposed to be used
with, and the no-op implementation to noop_fsync to make it obvious
what to expect. In addition add some documentation for both methods.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit 45db924089 ("powerpc/spufs: Remove
double check for non-negative dentry") removed the only user of the
out_dput label, so remove it and the code following it.
Gets rid of this warning:
arch/powerpc/platforms/cell/spufs/inode.c: In function 'spufs_create':
arch/powerpc/platforms/cell/spufs/inode.c:647: warning: label 'out_dput' defined but not used
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch removes an unnecessary double check if the dentry returned by
lookup_create() is actually non-negative. Since lookup_create() itself returns
an error in this case just remove the check.
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The spufs context directory contents definitions are not changed after
initialisation, so we can declare them as const. We can do the same
with the spu coredump reader callbacks too.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
... and don't bother in callers. Don't bother with zeroing i_blocks,
while we are at it - it's already been zeroed.
i_mode is not worth the effort; it has no common default value.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pass credentials through dentry_open() so that the COW creds patch can have
SELinux's flush_unauthorized_files() pass the appropriate creds back to itself
when it opens its null chardev.
The security_dentry_open() call also now takes a creds pointer, as does the
dentry_open hook in struct security_operations.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
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: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@ozlabs.org
Signed-off-by: James Morris <jmorris@namei.org>
This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.
This was posted for review some time ago and I believe its been in -mm
since then.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A mutex_unlock(&gang->aff_mutex) in spufs_create_context() is missing
in case spufs_context_open() fails. As a result, spu_create syscall
and spu_get_idle() may block.
This patch adds the mutex_unlock.
Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Andre Detsch <adetsch@br.ibm.com>
Currently, an empty spufs root inode has nlink count of 1. However,
the directory has two links; / -> spu and /spu/ -> .
This change increments the link count of the root inode in spufs.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres. Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.
Non-trivial places are:
arch/powerpc/mm/init_64.c
arch/powerpc/mm/hugetlbpage.c
This is flag day, yes.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Matt Mackall <mpm@selenic.com>
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, the .ctx debug file in spu context directories is always
present.
We'd prefer to prevent users from relying on this file, so add a
"debug" mount option to spufs. The .ctx file will only be added to
the context directories when this option is present.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Currently, spufs never specifies the i_size for the files in context
directories, so stat() always reports 0-byte files.
This change adds allows the spufs_dir_(nosched_)contents arrays to
specify a file size. This allows stat() to report correct file sizes,
and makes SEEK_END work.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
We need to acquire the parent i_mutex with I_MUTEX_PARENT to keep
lockdep happy.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Creating a spufs context or gand using spu_create should send an inotify
event so that things like performance monitors have an easy way to find
out about newly created contexts.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
None of these files use any of the functionality promised by
asm/semaphore.h. It's possible that they rely on it dragging in some
unrelated header file, but I can't build all these files, so we'll have
fix any build failures as they come up.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.
Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
<dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
struct path in every place where the stack can be traversed
- it reduces the overall code size:
without patch series:
text data bss dec hex filename
5321639 858418 715768 6895825 6938d1 vmlinux
with patch series:
text data bss dec hex filename
5320026 858418 715768 6894212 693284 vmlinux
This patch:
Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
