There is a bug in writepage and delete_inode which allows jdata files to
invalidate pages from the address space without being in a transaction at
the time. This causes problems in case the pages are in the journal. This
patch fixes that case and prevents the resulting oops.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

Move the contents of some headers which contained very
little into more sensible places, and remove the original
header files. This should make it easier to find things.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

This patch implements the FIEMAP ioctl for GFS2. We can use the generic
code (aside from a lock order issue, solved as per Ted Tso's suggestion)
for which I've introduced a new variant of the generic function. We also
have one exception to deal with, namely stuffed files, so we do that
"by hand", setting all the required flags.

This has been tested with a modified (I could only find an old version) of
Eric's test program, and appears to work correctly.

This patch does not currently support FIEMAP of xattrs, but the plan is to add
that feature at some future point.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
Cc: Theodore Tso <tytso@mit.edu>
Cc: Eric Sandeen <sandeen@redhat.com>

With the write_begin/write_end aops, page_symlink was broken because it
could no longer pass a GFP_NOFS type mask into the point where the
allocations happened.  They are done in write_begin, which would always
assume that the filesystem can be entered from reclaim.  This bug could
cause filesystem deadlocks.

The funny thing with having a gfp_t mask there is that it doesn't really
allow the caller to arbitrarily tinker with the context in which it can be
called.  It couldn't ever be GFP_ATOMIC, for example, because it needs to
take the page lock.  The only thing any callers care about is __GFP_FS
anyway, so turn that into a single flag.

Add a new flag for write_begin, AOP_FLAG_NOFS.  Filesystems can now act on
this flag in their write_begin function.  Change __grab_cache_page to
accept a nofs argument as well, to honour that flag (while we're there,
change the name to grab_cache_page_write_begin which is more instructive
and does away with random leading underscores).

This is really a more flexible way to go in the end anyway -- if a
filesystem happens to want any extra allocations aside from the pagecache
ones in ints write_begin function, it may now use GFP_KERNEL (rather than
GFP_NOFS) for common case allocations (eg.  ocfs2_alloc_write_ctxt, for a
random example).

[kosaki.motohiro@jp.fujitsu.com: fix ubifs]
[kosaki.motohiro@jp.fujitsu.com: fix fuse]
Signed-off-by: NNick Piggin <npiggin@suse.de>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
[ Cleaned up the calling convention: just pass in the AOP flags
  untouched to the grab_cache_page_write_begin() function.  That
  just simplifies everybody, and may even allow future expansion of the
  logic.   - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As suggested by Andreas Dilger, introduce a bgl_lock_ptr() helper in
<linux/blockgroup_lock.h> and add separate sb_bgl_lock() helpers to
filesystem specific header files to break the hidden dependency to
struct ext[234]_sb_info.

Also, while at it, convert the macros to static inlines to try make up
for all the times I broke Andrew Morton's tree.
Acked-by: NAndreas Dilger <adilger@sun.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* no allocations
* return void
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... just make it a binfmt handler like #! one.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

They are actually alpha vs.  i386/arm/m68k i.e. ecoff vs. aout.

In the only place where we actually tried to handle arm and i386/m68k in
different ways (START_DATA() in coredump handling), the arm variant
works for all of them (i386 and m68k have u.start_code set to 0).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

it's been used only in sunos compat
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.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: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/devpts/inode.c:324: warning: 'compare_init_pts_sb' defined but not used
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Just nail the oddments now while this code is being touched
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To support containers, allow multiple instances of devpts filesystem, such
that indices of ptys allocated in one instance are independent of ptys
allocated in other instances of devpts.

But to preserve backward compatibility, enable this support for multiple
instances only if:

	- CONFIG_DEVPTS_MULTIPLE_INSTANCES is set to Y, and
	- '-o newinstance' mount option is specified while mounting devpts

To use multi-instance mount, a container startup script could:

	$ ns_exec -cm /bin/bash
	$ umount /dev/pts
	$ mount -t devpts -o newinstance lxcpts /dev/pts
	$ mount -o bind /dev/pts/ptmx /dev/ptmx
	$ /usr/sbin/sshd -p 1234

where 'ns_exec -cm /bin/bash' is calls clone() with CLONE_NEWNS flag and execs
/bin/bash in the child process. A pty created by the sshd is not visible in
the original mount of /dev/pts.

USER-SPACE-IMPACT:
	- See Documentation/fs/devpts.txt (included in next patch) for user-
	  space impact in multi-instance and mixed-mode operation.
TODO:
	- Update mount(8), pts(4) man pages. Highlight impact of not
	  redirecting /dev/ptmx to /dev/pts/ptmx after a multi-instance mount.

Changelog[v6]:
	- [Dave Hansen] Use new get_init_pts_sb() interface
	- [Serge Hallyn] Don't bother displaying 'newinstance' in show_options
	- [Serge Hallyn] Use macros (PARSE_REMOUNT/PARSE_MOUNT) instead of 0/1.
	- [Serge Hallyn] Check error return from get_sb_single() (now
	  get_init_pts_sb())
	- devpts_pty_kill(): don't dput error dentries

Changelog[v5]:
	- Move get_sb_ref() definition to earlier patch
	- Move usage info to Documentation/filesystems/devpts.txt (next patch)
	- Make ptmx node even in init_pts_ns, now that default mode is 0000
	  (defined in earlier patch, enabled here).
	- Cache ptmx dentry and use to update mode during remount
	  (defined in earlier patch, enabled here).
	- Bugfix: explicitly ignore newinstance on remount (if newinstance was
	  specified on remount of initial mount, it would be ignored but
	  /proc/mounts would imply that the option was set)

Changelog[v4]:

	- Update patch description to address H. Peter Anvin's comments
	- Consolidate multi-instance mode code under new config token,
	  CONFIG_DEVPTS_MULTIPLE_INSTANCE.
	- Move usage-details from patch description to
	  Documentation/fs/devpts.txt

Changelog[v3]:
	- Rename new mount option to 'newinstance'
	- Create ptmx nodes only in 'newinstance' mounts
	- Bugfix: parse_mount_options() modifies @data but since we need to
	  parse the @data twice (once in devpts_get_sb() and once during
	  do_remount_sb()), parse a local copy of @data in devpts_get_sb().
	  (restructured code in devpts_get_sb() to fix this)

Changelog[v2]:
	- Support both single-mount and multiple-mount semantics and
	  provide '-onewmnt' option to select the semantics.
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

See comments in the function header for details. The new interface will
be used in a follow-on patch.

Changelog [v2]:
	[Dave Hansen] Replace get_sb_ref() in fs/super.c with get_init_pts_sb()
	and make the new interface private to devpts
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

/dev/ptmx is closely tied to the devpts filesystem. An open of /dev/ptmx,
allocates the next pty index and the associated device shows up in the
devpts fs as /dev/pts/n.

Wih multiple instancs of devpts filesystem, during an open of /dev/ptmx
we would be unable to determine which instance of the devpts is being
accessed.

So we move the 'ptmx' node into /dev/pts and use the inode of the 'ptmx'
node to identify the superblock and hence the devpts instance.  This patch
adds ability for the kernel to internally create the [ptmx, c, 5:2] device
when mounting devpts filesystem.  Since the ptmx node in devpts is new and
may surprise some userspace scripts, the default permissions for the new
node is 0000.  These permissions can be changed either using chmod or by
remounting with the new '-o ptmxmode=0666' mount option.

Changelog[v5]:
	- [Serge Hallyn bugfix]: Letting new_inode() assign inode number to
	  ptmx can collide with hand-assigning inode numbers to ptys. So,
	  hand-assign specific inode number to ptmx node also.
	- [Serge Hallyn]: Maybe safer to grab root dentry mutex while creating
	  ptmx node
	- [Bugfix with Serge Hallyn] Replace lookup_one_len() in mknod_ptmx()
	  wih d_alloc_name() (lookup during ->get_sb() locks up system). To
	  simplify patchset, fold the ptmx_dentry patch into this.

Changelog[v4]:
	- Change default permissions of pts/ptmx node to 0000.
	- Move code for ptmxmode under #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES.

Changelog[v3]:
	- Rename ptmx_mode to ptmxmode (for consistency with 'newinstance')

Changelog[v2]:
	- [H. Peter Anvin] Remove mknod() system call support and create the
	  ptmx node internally.

Changelog[v1]:
	- Earlier version of this patch enabled creating /dev/pts/tty as
	  well. As pointed out by Al Viro and H. Peter Anvin, that is not
	  really necessary.
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move code to parse mount options into a separate function so it can
(later) be shared between mount and remount operations.
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With support for multiple mounts of devpts, the 'config' structure really
represents per-mount options rather than config parameters. Rename 'config'
structure to 'pts_mount_opts' and store it in the super-block.
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To enable multiple mounts of devpts, 'allocated_ptys' must be a per-mount
variable rather than a global variable.  Move 'allocated_ptys' into the
super_block's s_fs_info.

Changelog[v2]:
	Define and use DEVPTS_SB() wrapper.
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove the 'devpts_root' global variable and find the root dentry using
the super_block. The super-block can be found from the device inode, using
the new wrapper, pts_sb_from_inode().

Changelog: This patch is based on an earlier patchset from Serge Hallyn
	   and Matt Helsley.
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

jfs version of Al Viro's nfsd race patches
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and the same for reiserfs.  The difference here is that we need
insert_inode_locked4() to match iget5_locked().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

ext3 analog of the previous patch
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* make ext2_new_inode() put the inode into icache in locked state
* do not unlock until the inode is fully set up; otherwise nfsd
might pick it in half-baked state.
* make sure that ext2_new_inode() does *not* lead to two inodes with the
same inumber hashed at the same time; otherwise a bogus fhandle coming
from nfsd might race with inode creation:

nfsd: iget_locked() creates inode
nfsd: try to read from disk, block on that.
ext2_new_inode(): allocate inode with that inumber
ext2_new_inode(): insert it into icache, set it up and dirty
ext2_write_inode(): get the relevant part of inode table in cache,
set the entry for our inode (and start writing to disk)
nfsd: get CPU again, look into inode table, see nice and sane on-disk
inode, set the in-core inode from it

oops - we have two in-core inodes with the same inumber live in icache,
both used for IO.  Welcome to fs corruption...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

new helpers - insert_inode_locked() and insert_inode_locked4().
Hash new inode, making sure that there's no such inode in icache
already.  If there is and it does not end up unhashed (as would
happen if we have nfsd trying to resolve a bogus fhandle), fail.
Otherwise insert our inode into hash and succeed.

In either case have i_state set to new+locked; cleanup ends up
being simpler with such calling conventions.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Creating a generic filesystem notification interface, fsnotify, which will be
used by inotify, dnotify, and eventually fanotify is really starting to
clutter the fs directory.  This patch simply moves inotify and dnotify into
fs/notify/inotify and fs/notify/dnotify respectively to make both current fs/
and future notification tidier.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

- iget5_locked in bdget really needs blockdev_superblock, instead of
  bd_mnt, so bd_mnt could be just a local variable;

- blockdev_superblock really needs __read_mostly, while local var bd_mnt
  not;

- make use of sb_is_blkdev_sb in bd_forget, instead of direct reference
  to blockdev_superblock.
Signed-off-by: NDenis ChengRq <crquan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Remove the hopelessly misguided ->dir_notify().  The only instance (cifs)
has been broken by design from the very beginning; the objects it creates
are never destroyed, keep references to struct file they can outlive, nothing
that could possibly evict them exists on close(2) path *and* no locking
whatsoever is done to prevent races with close(), should the previous, er,
deficiencies someday be dealt with.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Instead of creating the "filp" kmem_cache in vfs_caches_init(),
we can do it a litle be later in files_init(), so that filp_cachep
is static to fs/file_table.c
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

[AV: rediffed on top of unification of init_fs]
Initialization of init_fs still uses the deprecated RW_LOCK_UNLOCKED macro.
This patch updates it to use the __RW_LOCK_UNLOCKED(lock) macro.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

With all the nameidata removal there's no point anymore for this helper.
Of the three callers left two will go away with the next lookup series
anyway.

Also add proper kerneldoc to inode_permission as this is the main
permission check routine now.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

No need for the nameidata in may_open - a struct path is enough.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

walk_init_root is a tiny helper that is marked __always_inline, has just
one caller and an unused argument.  Just merge it into the caller.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We now pass on all MAY_ flags to the filesystems permission routines,
so remove the comment stating the contrary.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Explain that you really need to use the return value of d_path rather than
the buffer you passed into it.

Also fix the comment for seq_path(), the function arguments changed
recently but the comment hadn't been updated in sync.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

no function named d_put(), it should be dput().

Impact: fix document and comment, no functionality changed
Signed-off-by: NZhao Lei <zhaolei@cn.fuijtsu.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We want ->name.len to match the resulting name on *both*
source and target
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Ensure fast symlink targets are NUL-terminated, even if corrupted
on-disk.

Cc: Sergey S. Kostyliov <rathamahata@php4.ru>
Signed-off-by: NDuane Griffin <duaneg@dghda.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Ensure fast symlink targets are NUL-terminated, even if corrupted
on-disk.

Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NDuane Griffin <duaneg@dghda.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>