Commit Graph

143 Commits

Author SHA1 Message Date
Al Viro
f21f62208a ... and the same for vfsmount id/mount group id
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-24 08:15:26 -04:00
Trond Myklebust
3b22edc573 VFS: Switch init_mount_tree() to use the new create_mnt_ns() helper
Eliminates some duplicated code...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-24 08:15:24 -04:00
Trond Myklebust
cf8d2c11cb VFS: Add VFS helper functions for setting up private namespaces
The purpose of this patch is to improve the remote mount path lookup
support for distributed filesystems such as the NFSv4 client.

When given a mount command of the form "mount server:/foo/bar /mnt", the
NFSv4 client is required to look up the filehandle for "server:/", and
then look up each component of the remote mount path "foo/bar" in order
to find the directory that is actually going to be mounted on /mnt.
Following that remote mount path may involve following symlinks,
crossing server-side mount points and even following referrals to
filesystem volumes on other servers.

Since the standard VFS path lookup code already supports walking paths
that contain all these features (using in-kernel automounts for
following referrals) we would like to be able to reuse that rather than
duplicate the full path traversal functionality in the NFSv4 client code.

This patch therefore defines a VFS helper function create_mnt_ns(), that
sets up a temporary filesystem namespace and attaches a root filesystem to
it. It exports the create_mnt_ns() and put_mnt_ns() function for use by
filesystem modules.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-22 21:28:25 -07:00
Trond Myklebust
616511d039 VFS: Uninline the function put_mnt_ns()
In order to allow modules to use it without having to export vfsmount_lock.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-22 21:28:25 -07:00
Al Viro
4aa98cf768 Push BKL down into do_remount_sb()
[folded fix from Jiri Slaby]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:08 -04:00
Al Viro
7f78d4cd4c Push BKL down beyond VFS-only parts of do_mount()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:08 -04:00
Al Viro
6fac98dd21 Push BKL into do_mount()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:08 -04:00
Alexey Dobriyan
f3da392e9f dcache: extrace and use d_unlinked()
d_unlinked() will be used in middle-term to ban checkpointing when opened
but unlinked file is detected, and in long term, to detect such situation
and special case on it.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:06 -04:00
npiggin@suse.de
96029c4e09 fs: introduce mnt_clone_write
This patch speeds up lmbench lat_mmap test by about another 2% after the
first patch.

Before:
 avg = 462.286
 std = 5.46106

After:
 avg = 453.12
 std = 9.58257

(50 runs of each, stddev gives a reasonable confidence)

It does this by introducing mnt_clone_write, which avoids some heavyweight
operations of mnt_want_write if called on a vfsmount which we know already
has a write count; and mnt_want_write_file, which can call mnt_clone_write
if the file is open for write.

After these two patches, mnt_want_write and mnt_drop_write go from 7% on
the profile down to 1.3% (including mnt_clone_write).

[AV: mnt_want_write_file() should take file alone and derive mnt from it;
not only all callers have that form, but that's the only mnt about which
we know that it's already held for write if file is opened for write]

Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:02 -04:00
npiggin@suse.de
d3ef3d7351 fs: mnt_want_write speedup
This patch speeds up lmbench lat_mmap test by about 8%. lat_mmap is set up
basically to mmap a 64MB file on tmpfs, fault in its pages, then unmap it.
A microbenchmark yes, but it exercises some important paths in the mm.

Before:
 avg = 501.9
 std = 14.7773

After:
 avg = 462.286
 std = 5.46106

(50 runs of each, stddev gives a reasonable confidence, but there is quite
a bit of variation there still)

It does this by removing the complex per-cpu locking and counter-cache and
replaces it with a percpu counter in struct vfsmount. This makes the code
much simpler, and avoids spinlocks (although the msync is still pretty
costly, unfortunately). It results in about 900 bytes smaller code too. It
does increase the size of a vfsmount, however.

It should also give a speedup on large systems if CPUs are frequently operating
on different mounts (because the existing scheme has to operate on an atomic in
the struct vfsmount when switching between mounts). But I'm most interested in
the single threaded path performance for the moment.

[AV: minor cleanup]

Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:02 -04:00
Al Viro
1c755af4df switch lookup_mnt()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:01 -04:00
Al Viro
9393bd07cf switch follow_down()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:01 -04:00
Al Viro
589ff870ed Switch collect_mounts() to struct path
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:01 -04:00
Al Viro
dd5cae6e97 Don't bother with check_mnt() in do_add_mount() on shrinkable ones
These guys are what we add as submounts; checks for "is that attached in
our namespace" are simply irrelevant for those and counterproductive for
use of private vfsmount trees a-la what NFS folks want.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:35:59 -04:00
Al Viro
2a32cebd6c Fix races around the access to ->s_options
Put generic_show_options read access to s_options under rcu_read_lock,
split save_mount_options() into "we are setting it the first time"
(uses in foo_fill_super()) and "we are relacing and freeing the old one",
synchronize_rcu() before kfree() in the latter.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09 10:51:34 -04:00
Alessio Igor Bogani
67e55205ec vfs: umount_begin BKL pushdown
Push BKL down into ->umount_begin()

Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09 10:49:38 -04:00
Al Viro
e5d67f0715 Touch all affected namespaces on propagation of mount
We shouldn't just touch the namespace of current process

Caught-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-20 23:01:15 -04:00
Andi Kleen
613cbe3d48 Don't set relatime when noatime is specified
Since commit 0a1c01c947 ("Make relatime
default") when a file system is mounted explicitely with noatime it gets
both the MNT_RELATIME and MNT_NOATIME bits set.

This shows up like this in /proc/mounts:

  /dev/xxx /yyy ext3 rw,noatime,relatime,errors=continue,data=writeback 0 0

That looks strange.  The VFS uses noatime in this case, but both flags
are set.  So it's more a cosmetic issue, but still better to fix.

Cc: mjg@redhat.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-19 10:46:47 -07:00
Al Viro
5ad4e53bd5 Get rid of indirect include of fs_struct.h
Don't pull it in sched.h; very few files actually need it and those
can include directly.  sched.h itself only needs forward declaration
of struct fs_struct;

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:27 -04:00
Al Viro
3e93cd6718 Take fs_struct handling to new file (fs/fs_struct.c)
Pure code move; two new helper functions for nfsd and daemonize
(unshare_fs_struct() and daemonize_fs_struct() resp.; for now -
the same code as used to be in callers).  unshare_fs_struct()
exported (for nfsd, as copy_fs_struct()/exit_fs() used to be),
copy_fs_struct() and exit_fs() don't need exports anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:26 -04:00
Al Viro
f8ef3ed2be Get rid of bumping fs_struct refcount in pivot_root(2)
Not because execve races with _that_ are serious - we really
need a situation when final drop of fs_struct refcount is
done by something that used to have it as current->fs.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:25 -04:00
Linus Torvalds
3ae5080f4c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (37 commits)
  fs: avoid I_NEW inodes
  Merge code for single and multiple-instance mounts
  Remove get_init_pts_sb()
  Move common mknod_ptmx() calls into caller
  Parse mount options just once and copy them to super block
  Unroll essentials of do_remount_sb() into devpts
  vfs: simple_set_mnt() should return void
  fs: move bdev code out of buffer.c
  constify dentry_operations: rest
  constify dentry_operations: configfs
  constify dentry_operations: sysfs
  constify dentry_operations: JFS
  constify dentry_operations: OCFS2
  constify dentry_operations: GFS2
  constify dentry_operations: FAT
  constify dentry_operations: FUSE
  constify dentry_operations: procfs
  constify dentry_operations: ecryptfs
  constify dentry_operations: CIFS
  constify dentry_operations: AFS
  ...
2009-03-27 16:23:12 -07:00
Sukadev Bhattiprolu
a3ec947c85 vfs: simple_set_mnt() should return void
simple_set_mnt() is defined as returning 'int' but always returns 0.
Callers assume simple_set_mnt() never fails and don't properly cleanup if
it were to _ever_ fail.  For instance, get_sb_single() and get_sb_nodev()
should:

        up_write(sb->s_unmount);
        deactivate_super(sb);

if simple_set_mnt() fails.

Since simple_set_mnt() never fails, would be cleaner if it did not
return anything.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:44:03 -04:00
Matthew Garrett
0a1c01c947 Make relatime default
Change the default behaviour of the kernel to use relatime for all
filesystems. This can be overridden with the "strictatime" mount
option.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-26 11:01:10 -07:00
Matthew Garrett
d0adde574b Add a strictatime mount option
Add support for explicitly requesting full atime updates. This makes it
possible for kernels to default to relatime but still allow userspace to
override it.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-26 10:56:35 -07:00
Al Viro
1a88b5364b Fix incomplete __mntput locking
Getting this wrong caused

	WARNING: at fs/namespace.c:636 mntput_no_expire+0xac/0xf2()

due to optimistically checking cpu_writer->mnt outside the spinlock.

Here's what we really want:
 * we know that nobody will set cpu_writer->mnt to mnt from now on
 * all changes to that sucker are done under cpu_writer->lock
 * we want the laziest equivalent of
	spin_lock(&cpu_writer->lock);
	if (likely(cpu_writer->mnt != mnt)) {
		spin_unlock(&cpu_writer->lock);
		continue;
	}
	/* do stuff */
  that would make sure we won't miss earlier setting of ->mnt done by
  another CPU.

Anyway, for now we just move the spin_lock() earlier and move the test
into the properly locked region.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-and-tested-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-17 14:02:08 -08:00
Heiko Carstens
3480b25743 [CVE-2009-0029] System call wrappers part 14
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:24 +01:00
Heiko Carstens
bdc480e3be [CVE-2009-0029] System call wrappers part 10
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:22 +01:00
Julia Lawall
5cc4a0341a fs/namespace.c: drop code after return
The extra semicolon serves no purpose.

Signed-off-by: Julia Lawall <julia@diku.dk>
Reviewed-by: Richard Genoud <richard.genoud@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:38 -05:00
James Morris
2b82892565 Merge branch 'master' into next
Conflicts:
	security/keys/internal.h
	security/keys/process_keys.c
	security/keys/request_key.c

Fixed conflicts above by using the non 'tsk' versions.

Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 11:29:12 +11:00
David Howells
da9592edeb CRED: Wrap task credential accesses in the filesystem subsystem
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>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:05 +11:00
Eric W. Biederman
afef80b3d8 vfs: fix shrink_submounts
In the last refactoring of shrink_submounts a variable was not completely
renamed.  So finish the renaming of mnt to m now.

Without this if you attempt to mount an nfs mount that has both automatic
nfs sub mounts on it, and has normal mounts on it.  The unmount will
succeed when it should not.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 17:17:17 -08:00
Dan Williams
0e55a7cca4 [RFC PATCH] touch_mnt_namespace when the mount flags change
Daemons that need to be launched while the rootfs is read-only can now
poll /proc/mounts to be notified when their O_RDWR requests may no
longer end in EROFS.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-10-23 05:13:23 -04:00
Al Viro
0a0d8a4675 [PATCH] no need for noinline stuff in fs/namespace.c anymore
Stack footprint from hell had been due to many struct nameidata in there.
No more.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-23 03:34:22 -04:00
Al Viro
2d92ab3c62 [PATCH] finally get rid of nameidata in namespace.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-23 03:34:20 -04:00
Al Viro
8d66bf5481 [PATCH] pass struct path * to do_add_mount()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01 11:25:32 -04:00
Al Viro
2d8f30380a [PATCH] sanitize __user_walk_fd() et.al.
* do not pass nameidata; struct path is all the callers want.
* switch to new helpers:
	user_path_at(dfd, pathname, flags, &path)
	user_path(pathname, &path)
	user_lpath(pathname, &path)
	user_path_dir(pathname, &path)  (fail if not a directory)
  The last 3 are trivial macro wrappers for the first one.
* remove nameidata in callers.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:34 -04:00
Li Zefan
88b387824f [PATCH] vfs: use kstrdup() and check failing allocation
- use kstrdup() instead of kmalloc() + memcpy()
- return NULL if allocating ->mnt_devname failed
- mnt_devname should be const

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:24 -04:00
Al Viro
7f2da1e7d0 [PATCH] kill altroot
long overdue...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:20 -04:00
Arjan van de Ven
5c752ad9f3 Use WARN() in fs/
Use WARN() instead of a printk+WARN_ON() pair; this way the message
becomes part of the warning section for better reporting/collection.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:07 -07:00
Eric Paris
2069f45784 LSM/SELinux: show LSM mount options in /proc/mounts
This patch causes SELinux mount options to show up in /proc/mounts.  As
with other code in the area seq_put errors are ignored.  Other LSM's
will not have their mount options displayed until they fill in their own
security_sb_show_options() function.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14 15:02:05 +10:00
Harvey Harrison
8e24eea728 fs: replace remaining __FUNCTION__ occurrences
__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>
2008-04-30 08:29:54 -07:00
Jan Blunck
7ec02ef159 vfs: remove lives_below_in_same_fs()
Remove lives_below_in_same_fs() since is_subdir() from fs/dcache.c is
providing the same functionality.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:06 -07:00
Jan Kara
8794b5b246 quota: remove superfluous DQUOT_OFF() in fs/namespace.c
We don't need to turn quotas off before remounting root ro, because
do_remount_sb() already handles this.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:33 -07:00
Al Viro
42faad9965 [PATCH] restore sane ->umount_begin() API
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-25 09:23:25 -04:00
Miklos Szeredi
97e7e0f71d [patch 7/7] vfs: mountinfo: show dominating group id
Show peer group ID of nearest dominating group that has intersection
with the mount's namespace.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-23 00:05:09 -04:00
Ram Pai
2d4d4864ac [patch 6/7] vfs: mountinfo: add /proc/<pid>/mountinfo
[mszeredi@suse.cz] rewrite and split big patch into managable chunks

/proc/mounts in its current form lacks important information:

 - propagation state
 - root of mount for bind mounts
 - the st_dev value used within the filesystem
 - identifier for each mount and it's parent

It also suffers from the following problems:

 - not easily extendable
 - ambiguity of mountpoints within a chrooted environment
 - doesn't distinguish between filesystem dependent and independent options
 - doesn't distinguish between per mount and per super block options

This patch introduces /proc/<pid>/mountinfo which attempts to address
all these deficiencies.

Code shared between /proc/<pid>/mounts and /proc/<pid>/mountinfo is
extracted into separate functions.

Thanks to Al Viro for the help in getting the design right.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-23 00:05:03 -04:00
Miklos Szeredi
a1a2c409b6 [patch 5/7] vfs: mountinfo: allow using process root
Allow /proc/<pid>/mountinfo to use the root of <pid> to calculate
mountpoints.

 - move definition of 'struct proc_mounts' to <linux/mnt_namespace.h>
 - add the process's namespace and root to this structure
 - pass a pointer to 'struct proc_mounts' into seq_operations

In addition the following cleanups are made:

 - use a common open function for /proc/<pid>/{mounts,mountstat}
 - surround namespace.c part of these proc files with #ifdef CONFIG_PROC_FS
 - make the seq_operations structures const

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-23 00:04:57 -04:00
Miklos Szeredi
719f5d7f0b [patch 4/7] vfs: mountinfo: add mount peer group ID
Add a unique ID to each peer group using the IDR infrastructure.  The
identifiers are reused after the peer group dissolves.

The IDR structures are protected by holding namepspace_sem for write
while allocating or deallocating IDs.

IDs are allocated when a previously unshared vfsmount becomes the
first member of a peer group.  When a new member is added to an
existing group, the ID is copied from one of the old members.

IDs are freed when the last member of a peer group is unshared.

Setting the MNT_SHARED flag on members of a subtree is done as a
separate step, after all the IDs have been allocated.  This way an
allocation failure can be cleaned up easilty, without affecting the
propagation state.

Based on design sketch by Al Viro.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-23 00:04:51 -04:00
Miklos Szeredi
73cd49ecdd [patch 3/7] vfs: mountinfo: add mount ID
Add a unique ID to each vfsmount using the IDR infrastructure.  The
identifiers are reused after the vfsmount is freed.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-23 00:04:45 -04:00