Commit graph

560 commits

Author SHA1 Message Date
Linus Torvalds
aab174f0df Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs update from Al Viro:

 - big one - consolidation of descriptor-related logics; almost all of
   that is moved to fs/file.c

   (BTW, I'm seriously tempted to rename the result to fd.c.  As it is,
   we have a situation when file_table.c is about handling of struct
   file and file.c is about handling of descriptor tables; the reasons
   are historical - file_table.c used to be about a static array of
   struct file we used to have way back).

   A lot of stray ends got cleaned up and converted to saner primitives,
   disgusting mess in android/binder.c is still disgusting, but at least
   doesn't poke so much in descriptor table guts anymore.  A bunch of
   relatively minor races got fixed in process, plus an ext4 struct file
   leak.

 - related thing - fget_light() partially unuglified; see fdget() in
   there (and yes, it generates the code as good as we used to have).

 - also related - bits of Cyrill's procfs stuff that got entangled into
   that work; _not_ all of it, just the initial move to fs/proc/fd.c and
   switch of fdinfo to seq_file.

 - Alex's fs/coredump.c spiltoff - the same story, had been easier to
   take that commit than mess with conflicts.  The rest is a separate
   pile, this was just a mechanical code movement.

 - a few misc patches all over the place.  Not all for this cycle,
   there'll be more (and quite a few currently sit in akpm's tree)."

Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
  MAX_LFS_FILESIZE should be a loff_t
  compat: fs: Generic compat_sys_sendfile implementation
  fs: push rcu_barrier() from deactivate_locked_super() to filesystems
  btrfs: reada_extent doesn't need kref for refcount
  coredump: move core dump functionality into its own file
  coredump: prevent double-free on an error path in core dumper
  usb/gadget: fix misannotations
  fcntl: fix misannotations
  ceph: don't abuse d_delete() on failure exits
  hypfs: ->d_parent is never NULL or negative
  vfs: delete surplus inode NULL check
  switch simple cases of fget_light to fdget
  new helpers: fdget()/fdput()
  switch o2hb_region_dev_write() to fget_light()
  proc_map_files_readdir(): don't bother with grabbing files
  make get_file() return its argument
  vhost_set_vring(): turn pollstart/pollstop into bool
  switch prctl_set_mm_exe_file() to fget_light()
  switch xfs_find_handle() to fget_light()
  switch xfs_swapext() to fget_light()
  ...
2012-10-02 20:25:04 -07:00
Linus Torvalds
437589a74b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace changes from Eric Biederman:
 "This is a mostly modest set of changes to enable basic user namespace
  support.  This allows the code to code to compile with user namespaces
  enabled and removes the assumption there is only the initial user
  namespace.  Everything is converted except for the most complex of the
  filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs,
  nfs, ocfs2 and xfs as those patches need a bit more review.

  The strategy is to push kuid_t and kgid_t values are far down into
  subsystems and filesystems as reasonable.  Leaving the make_kuid and
  from_kuid operations to happen at the edge of userspace, as the values
  come off the disk, and as the values come in from the network.
  Letting compile type incompatible compile errors (present when user
  namespaces are enabled) guide me to find the issues.

  The most tricky areas have been the places where we had an implicit
  union of uid and gid values and were storing them in an unsigned int.
  Those places were converted into explicit unions.  I made certain to
  handle those places with simple trivial patches.

  Out of that work I discovered we have generic interfaces for storing
  quota by projid.  I had never heard of the project identifiers before.
  Adding full user namespace support for project identifiers accounts
  for most of the code size growth in my git tree.

  Ultimately there will be work to relax privlige checks from
  "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing
  root in a user names to do those things that today we only forbid to
  non-root users because it will confuse suid root applications.

  While I was pushing kuid_t and kgid_t changes deep into the audit code
  I made a few other cleanups.  I capitalized on the fact we process
  netlink messages in the context of the message sender.  I removed
  usage of NETLINK_CRED, and started directly using current->tty.

  Some of these patches have also made it into maintainer trees, with no
  problems from identical code from different trees showing up in
  linux-next.

  After reading through all of this code I feel like I might be able to
  win a game of kernel trivial pursuit."

Fix up some fairly trivial conflicts in netfilter uid/git logging code.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits)
  userns: Convert the ufs filesystem to use kuid/kgid where appropriate
  userns: Convert the udf filesystem to use kuid/kgid where appropriate
  userns: Convert ubifs to use kuid/kgid
  userns: Convert squashfs to use kuid/kgid where appropriate
  userns: Convert reiserfs to use kuid and kgid where appropriate
  userns: Convert jfs to use kuid/kgid where appropriate
  userns: Convert jffs2 to use kuid and kgid where appropriate
  userns: Convert hpfs to use kuid and kgid where appropriate
  userns: Convert btrfs to use kuid/kgid where appropriate
  userns: Convert bfs to use kuid/kgid where appropriate
  userns: Convert affs to use kuid/kgid wherwe appropriate
  userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids
  userns: On ia64 deal with current_uid and current_gid being kuid and kgid
  userns: On ppc convert current_uid from a kuid before printing.
  userns: Convert s390 getting uid and gid system calls to use kuid and kgid
  userns: Convert s390 hypfs to use kuid and kgid where appropriate
  userns: Convert binder ipc to use kuids
  userns: Teach security_path_chown to take kuids and kgids
  userns: Add user namespace support to IMA
  userns: Convert EVM to deal with kuids and kgids in it's hmac computation
  ...
2012-10-02 11:11:09 -07:00
Al Viro
2903ff019b switch simple cases of fget_light to fdget
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 22:20:08 -04:00
Al Viro
f6d2ac5ca7 namei.c: fix BS comment
get_write_access() is needed for nfsd, not binfmt_aout (the latter
has no business doing anything of that kind, of course)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 21:10:02 -04:00
Randy Dunlap
55852635a8 fs: fix fs/namei.c kernel-doc warnings
Fix kernel-doc warnings in fs/namei.c:

Warning(fs/namei.c:360): No description found for parameter 'inode'
Warning(fs/namei.c:672): No description found for parameter 'nd'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc:	Alexander Viro <viro@zeniv.linux.org.uk>
Cc:	linux-fsdevel@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-22 10:30:10 -04:00
Sage Weil
62b2ce964b vfs: fix propagation of atomic_open create error on negative dentry
If ->atomic_open() returns -ENOENT, we take care to return the create
error (e.g., EACCES), if any.  Do the same when ->atomic_open() returns 1
and provides a negative dentry.

This fixes a regression where an unprivileged open O_CREAT fails with
ENOENT instead of EACCES, introduced with the new atomic_open code.  It
is tested by the open/08.t test in the pjd posix test suite, and was
observed on top of fuse (backed by ceph-fuse).

Signed-off-by: Sage Weil <sage@inktank.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2012-08-16 19:29:09 +02:00
Miklos Szeredi
38227f78a5 vfs: pass right create mode to may_o_create()
Pass the umask-ed create mode to may_o_create() instead of the original one.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
2012-08-15 13:01:24 +02:00
Miklos Szeredi
62b259d8b3 vfs: atomic_open(): fix create mode usage
Don't mask S_ISREG off the create mode before passing to ->atomic_open().  Other
methods (->create, ->mknod) also get the complete file mode and filesystems
expect it.

Reported-by: Steve <steveamigauk@yahoo.co.uk>
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
2012-08-15 13:01:24 +02:00
Eric W. Biederman
81abe27b10 userns: Fix link restrictions to use uid_eq
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2012-08-03 19:23:45 -07:00
Jan Kara
c30dabfe5d fs: Push mnt_want_write() outside of i_mutex
Currently, mnt_want_write() is sometimes called with i_mutex held and sometimes
without it. This isn't really a problem because mnt_want_write() is a
non-blocking operation (essentially has a trylock semantics) but when the
function starts to handle also frozen filesystems, it will get a full lock
semantics and thus proper lock ordering has to be established. So move
all mnt_want_write() calls outside of i_mutex.

One non-trivial case needing conversion is kern_path_create() /
user_path_create() which didn't include mnt_want_write() but now needs to
because it acquires i_mutex.  Because there are virtual file systems which
don't bother with freeze / remount-ro protection we actually provide both
versions of the function - one which calls mnt_want_write() and one which does
not.

[AV: scratch the previous, mnt_want_write() has been moved to kern_path_create()
by now]

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 01:02:49 +04:00
Al Viro
64894cf843 simplify lookup_open()/atomic_open() - do the temporary mnt_want_write() early
The write ref to vfsmount taken in lookup_open()/atomic_open() is going to
be dropped; we take the one to stay in dentry_open().  Just grab the temporary
in caller if it looks like we are going to need it (create/truncate/writable open)
and pass (by value) "has it succeeded" flag.  Instead of doing mnt_want_write()
inside, check that flag and treat "false" as "mnt_want_write() has just failed".
mnt_want_write() is cheap and the things get considerably simpler and more robust
that way - we get it and drop it in the same function, to start with, rather
than passing a "has something in the guts of really scary functions taken it"
back to caller.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-31 00:53:35 +04:00
Al Viro
f8310c5920 fix O_EXCL handling for devices
O_EXCL without O_CREAT has different semantics; it's "fail if already opened",
not "fail if already exists".  commit 71574865 broke that...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-30 11:50:30 +04:00
Kees Cook
a51d9eaa41 fs: add link restriction audit reporting
Adds audit messages for unexpected link restriction violations so that
system owners will have some sort of potentially actionable information
about misbehaving processes.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:43:08 +04:00
Kees Cook
800179c9b8 fs: add link restrictions
This adds symlink and hardlink restrictions to the Linux VFS.

Symlinks:

A long-standing class of security issues is the symlink-based
time-of-check-time-of-use race, most commonly seen in world-writable
directories like /tmp. The common method of exploitation of this flaw
is to cross privilege boundaries when following a given symlink (i.e. a
root process follows a symlink belonging to another user). For a likely
incomplete list of hundreds of examples across the years, please see:
http://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=/tmp

The solution is to permit symlinks to only be followed when outside
a sticky world-writable directory, or when the uid of the symlink and
follower match, or when the directory owner matches the symlink's owner.

Some pointers to the history of earlier discussion that I could find:

 1996 Aug, Zygo Blaxell
  http://marc.info/?l=bugtraq&m=87602167419830&w=2
 1996 Oct, Andrew Tridgell
  http://lkml.indiana.edu/hypermail/linux/kernel/9610.2/0086.html
 1997 Dec, Albert D Cahalan
  http://lkml.org/lkml/1997/12/16/4
 2005 Feb, Lorenzo Hernández García-Hierro
  http://lkml.indiana.edu/hypermail/linux/kernel/0502.0/1896.html
 2010 May, Kees Cook
  https://lkml.org/lkml/2010/5/30/144

Past objections and rebuttals could be summarized as:

 - Violates POSIX.
   - POSIX didn't consider this situation and it's not useful to follow
     a broken specification at the cost of security.
 - Might break unknown applications that use this feature.
   - Applications that break because of the change are easy to spot and
     fix. Applications that are vulnerable to symlink ToCToU by not having
     the change aren't. Additionally, no applications have yet been found
     that rely on this behavior.
 - Applications should just use mkstemp() or O_CREATE|O_EXCL.
   - True, but applications are not perfect, and new software is written
     all the time that makes these mistakes; blocking this flaw at the
     kernel is a single solution to the entire class of vulnerability.
 - This should live in the core VFS.
   - This should live in an LSM. (https://lkml.org/lkml/2010/5/31/135)
 - This should live in an LSM.
   - This should live in the core VFS. (https://lkml.org/lkml/2010/8/2/188)

Hardlinks:

On systems that have user-writable directories on the same partition
as system files, a long-standing class of security issues is the
hardlink-based time-of-check-time-of-use race, most commonly seen in
world-writable directories like /tmp. The common method of exploitation
of this flaw is to cross privilege boundaries when following a given
hardlink (i.e. a root process follows a hardlink created by another
user). Additionally, an issue exists where users can "pin" a potentially
vulnerable setuid/setgid file so that an administrator will not actually
upgrade a system fully.

The solution is to permit hardlinks to only be created when the user is
already the existing file's owner, or if they already have read/write
access to the existing file.

Many Linux users are surprised when they learn they can link to files
they have no access to, so this change appears to follow the doctrine
of "least surprise". Additionally, this change does not violate POSIX,
which states "the implementation may require that the calling process
has permission to access the existing file"[1].

This change is known to break some implementations of the "at" daemon,
though the version used by Fedora and Ubuntu has been fixed[2] for
a while. Otherwise, the change has been undisruptive while in use in
Ubuntu for the last 1.5 years.

[1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/linkat.html
[2] http://anonscm.debian.org/gitweb/?p=collab-maint/at.git;a=commitdiff;h=f4114656c3a6c6f6070e315ffdf940a49eda3279

This patch is based on the patches in Openwall and grsecurity, along with
suggestions from Al Viro. I have added a sysctl to enable the protected
behavior, and documentation.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:37:58 +04:00
Jeff Layton
3134f37e93 vfs: don't let do_last pass negative dentry to audit_inode
I can reliably reproduce the following panic by simply setting an audit
rule on a recent 3.5.0+ kernel:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
 IP: [<ffffffff810d1250>] audit_copy_inode+0x10/0x90
 PGD 7acd9067 PUD 7b8fb067 PMD 0
 Oops: 0000 [#86] SMP
 Modules linked in: nfs nfs_acl auth_rpcgss fscache lockd sunrpc tpm_bios btrfs zlib_deflate libcrc32c kvm_amd kvm joydev virtio_net pcspkr i2c_piix4 floppy virtio_balloon microcode virtio_blk cirrus drm_kms_helper ttm drm i2c_core [last unloaded: scsi_wait_scan]
 CPU 0
 Pid: 1286, comm: abrt-dump-oops Tainted: G      D      3.5.0+ #1 Bochs Bochs
 RIP: 0010:[<ffffffff810d1250>]  [<ffffffff810d1250>] audit_copy_inode+0x10/0x90
 RSP: 0018:ffff88007aebfc38  EFLAGS: 00010282
 RAX: 0000000000000000 RBX: ffff88003692d860 RCX: 00000000000038c4
 RDX: 0000000000000000 RSI: ffff88006baf5d80 RDI: ffff88003692d860
 RBP: ffff88007aebfc68 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
 R13: ffff880036d30f00 R14: ffff88006baf5d80 R15: ffff88003692d800
 FS:  00007f7562634740(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000040 CR3: 000000003643d000 CR4: 00000000000006f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process abrt-dump-oops (pid: 1286, threadinfo ffff88007aebe000, task ffff880079614530)
 Stack:
  ffff88007aebfdf8 ffff88007aebff28 ffff88007aebfc98 ffffffff81211358
  ffff88003692d860 0000000000000000 ffff88007aebfcc8 ffffffff810d4968
  ffff88007aebfcc8 ffff8800000038c4 0000000000000000 0000000000000000
 Call Trace:
  [<ffffffff81211358>] ? ext4_lookup+0xe8/0x160
  [<ffffffff810d4968>] __audit_inode+0x118/0x2d0
  [<ffffffff811955a9>] do_last+0x999/0xe80
  [<ffffffff81191fe8>] ? inode_permission+0x18/0x50
  [<ffffffff81171efa>] ? kmem_cache_alloc_trace+0x11a/0x130
  [<ffffffff81195b4a>] path_openat+0xba/0x420
  [<ffffffff81196111>] do_filp_open+0x41/0xa0
  [<ffffffff811a24bd>] ? alloc_fd+0x4d/0x120
  [<ffffffff811855cd>] do_sys_open+0xed/0x1c0
  [<ffffffff810d40cc>] ? __audit_syscall_entry+0xcc/0x300
  [<ffffffff811856c1>] sys_open+0x21/0x30
  [<ffffffff81611ca9>] system_call_fastpath+0x16/0x1b
  RSP <ffff88007aebfc38>
 CR2: 0000000000000040

The problem is that do_last is passing a negative dentry to audit_inode.
The comments on lookup_open note that it can pass back a negative dentry
if O_CREAT is not set.

This patch fixes the oops, but I'm not clear on whether there's a better
approach.

Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:27:03 +04:00
Al Viro
a8104a9fcd pull mnt_want_write()/mnt_drop_write() into kern_path_create()/done_path_create() resp.
One side effect - attempt to create a cross-device link on a read-only fs fails
with EROFS instead of EXDEV now.  Makes more sense, POSIX allows, etc.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:24:15 +04:00
Al Viro
8e4bfca1d1 mknod: take sanity checks on mode into the very beginning
Note that applying umask can't affect their results.  While
that affects errno in cases like
	mknod("/no_such_directory/a", 030000)
yielding -EINVAL (due to impossible mode_t) instead of
-ENOENT (due to inexistent directory), IMO that makes a lot
more sense, POSIX allows to return either and any software
that relies on getting -ENOENT instead of -EINVAL in that
case deserves everything it gets.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:24:14 +04:00
Al Viro
921a1650de new helper: done_path_create()
releases what needs to be released after {kern,user}_path_create()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:24:13 +04:00
Al Viro
32a7991b6a tidy up namei.c a bit
locking/unlocking for rcu walk taken to a couple of inline helpers

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-23 00:00:55 +04:00
Al Viro
3c0a616368 unobfuscate follow_up() a bit
really convoluted test in there has grown up during struct mount
introduction; what it checks is that we'd reached the root of
mount tree.
2012-07-23 00:00:45 +04:00
Al Viro
1e0ea00144 use __lookup_hash() in kern_path_parent()
No need to bother with lookup_one_len() here - it's an overkill

Signed-off-by Al Viro <viro@zeniv.linux.org.uk>
2012-07-22 23:57:53 +04:00
David Howells
0bdaea9017 VFS: Split inode_permission()
Split inode_permission() into inode- and superblock-dependent parts.

This is aimed at unionmounts where the superblock from the upper layer has to
be checked rather than the superblock from the lower layer as the upper layer
may be writable, thus allowing an unwritable file from the lower layer to be
copied up and modified.

Original-author: Valerie Aurora <vaurora@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com> (Further development)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:38:36 +04:00
David Howells
f015f1267b VFS: Comment mount following code
Add comments describing what the directions "up" and "down" mean and ref count
handling to the VFS mount following family of functions.

Signed-off-by: Valerie Aurora <vaurora@redhat.com> (Original author)
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:38:32 +04:00
Christoph Hellwig
b5fb63c183 fs: add nd_jump_link
Add a helper that abstracts out the jump to an already parsed struct path
from ->follow_link operation from procfs.  Not only does this clean up
the code by moving the two sides of this game into a single helper, but
it also prepares for making struct nameidata private to namei.c

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:35:40 +04:00
Christoph Hellwig
408ef013cc fs: move path_put on failure out of ->follow_link
Currently the non-nd_set_link based versions of ->follow_link are expected
to do a path_put(&nd->path) on failure.  This calling convention is unexpected,
undocumented and doesn't match what the nd_set_link-based instances do.

Move the path_put out of the only non-nd_set_link based ->follow_link
instance into the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:35:35 +04:00
Al Viro
79714f72d3 get rid of kern_path_parent()
all callers want the same thing, actually - a kinda-sorta analog of
kern_path_create().  I.e. they want parent vfsmount/dentry (with
->i_mutex held, to make sure the child dentry is still their child)
+ the child dentry.

Signed-off-by Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:35:02 +04:00
David Howells
1acf0af9b9 VFS: Fix the banner comment on lookup_open()
Since commit 197e37d9, the banner comment on lookup_open() no longer matches
what the function returns.  It used to return a struct file pointer or NULL and
now it returns an integer and is passed the struct file pointer it is to use
amongst its arguments.  Update the comment to reflect this.

Also add a banner comment to atomic_open().

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:57 +04:00
Al Viro
312b63fba9 don't pass nameidata * to vfs_create()
all we want is a boolean flag, same as the method gets now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:50 +04:00
Al Viro
ebfc3b49a7 don't pass nameidata to ->create()
boolean "does it have to be exclusive?" flag is passed instead;
Local filesystem should just ignore it - the object is guaranteed
not to be there yet.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:47 +04:00
Al Viro
72bd866a01 fs/namei.c: don't pass nameidata to __lookup_hash() and lookup_real()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:40 +04:00
Al Viro
00cd8dd3bf stop passing nameidata to ->lookup()
Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument.  And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:32 +04:00
Al Viro
201f956e43 fs/namei.c: don't pass namedata to lookup_dcache()
just the flags...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:25 +04:00
Al Viro
4ce16ef3fe fs/namei.c: don't pass nameidata to d_revalidate()
since the method wrapped by it doesn't need that anymore...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:21 +04:00
Al Viro
0b728e1911 stop passing nameidata * to ->d_revalidate()
Just the lookup flags.  Die, bastard, die...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:14 +04:00
Al Viro
2675a4eb6a fs/namei.c: get do_last() and friends return int
Same conventions as for ->atomic_open().  Trimmed the
forest of labels a bit, while we are at it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:43 +04:00
Al Viro
30d9049474 kill struct opendata
Just pass struct file *.  Methods are happier that way...
There's no need to return struct file * from finish_open() now,
so let it return int.  Next: saner prototypes for parts in
namei.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:39 +04:00
Al Viro
a4a3bdd778 kill opendata->{mnt,dentry}
->filp->f_path is there for purpose...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:37 +04:00
Al Viro
d95852777b make ->atomic_open() return int
Change of calling conventions:
old		new
NULL		1
file		0
ERR_PTR(-ve)	-ve

Caller *knows* that struct file *; no need to return it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:35 +04:00
Al Viro
3d8a00d209 don't modify od->filp at all
make put_filp() conditional on flag set by finish_open()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:33 +04:00
Al Viro
47237687d7 ->atomic_open() prototype change - pass int * instead of bool *
... and let finish_open() report having opened the file via that sucker.
Next step: don't modify od->filp at all.

[AV: FILE_CREATE was already used by cifs; Miklos' fix folded]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:31 +04:00
Miklos Szeredi
a8277b9baa vfs: move O_DIRECT check to common code
Perform open_check_o_direct() in a common place in do_last after opening the
file.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:28 +04:00
Miklos Szeredi
f60dc3db6e vfs: do_last(): clean up retry
Move the lookup retry logic to the bottom of the function to make the normal
case simpler to read.

Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:26 +04:00
Miklos Szeredi
77d660a8a8 vfs: do_last(): clean up bool
Consistently use bool for boolean values in do_last().

Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:24 +04:00
Miklos Szeredi
e83db16722 vfs: do_last(): clean up labels
Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:21 +04:00
Miklos Szeredi
aa4caadb70 vfs: do_last(): clean up error handling
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:20 +04:00
Miklos Szeredi
015c3bbcd8 vfs: remove open intents from nameidata
All users of open intents have been converted to use ->atomic_{open,create}.

This patch gets rid of nd->intent.open and related infrastructure.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:18 +04:00
Miklos Szeredi
d18e9008c3 vfs: add i_op->atomic_open()
Add a new inode operation which is called on the last component of an open.
Using this the filesystem can look up, possibly create and open the file in one
atomic operation.  If it cannot perform this (e.g. the file type turned out to
be wrong) it may signal this by returning NULL instead of an open struct file
pointer.

i_op->atomic_open() is only called if the last component is negative or needs
lookup.  Handling cached positive dentries here doesn't add much value: these
can be opened using f_op->open().  If the cached file turns out to be invalid,
the open can be retried, this time using ->atomic_open() with a fresh dentry.

For now leave the old way of using open intents in lookup and revalidate in
place.  This will be removed once all the users are converted.

David Howells noticed that if ->atomic_open() opens the file but does not create
it, handle_truncate() will be called on it even if it is not a regular file.
Fix this by checking the file type in this case too.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:04 +04:00
Miklos Szeredi
54ef487241 vfs: lookup_open(): expand lookup_hash()
Copy __lookup_hash() into lookup_open().  The next patch will insert the atomic
open call just before the real lookup.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:02 +04:00
Miklos Szeredi
d58ffd35c1 vfs: add lookup_open()
Split out lookup + maybe create from do_last().  This is the part under i_mutex
protection.

The function is called lookup_open() and returns a filp even though the open
part is not used yet.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:01 +04:00
Miklos Szeredi
7157486541 vfs: do_last(): common slow lookup
Make the slow lookup part of O_CREAT and non-O_CREAT opens common.

This allows atomic_open to be hooked into the slow lookup part.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:33:00 +04:00