Commit Graph

312 Commits

Author SHA1 Message Date
Ian Kent
6035974147 autofs: use path_has_submounts() to fix unreliable have_submount() checks
If an automount mount is clone(2)ed into a file system that is propagation
private, when it later expires in the originating namespace, subsequent
calls to autofs ->d_automount() for that dentry in the original namespace
will return ELOOP until the mount is umounted in the cloned namespace.

Now that a struct path is available where needed use path_has_submounts()
instead of have_submounts() so we don't get false positives when checking
if a dentry is a mount point or contains mounts in the current namespace.

Link: http://lkml.kernel.org/r/20161011053423.27645.91233.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-03 20:51:49 -05:00
Ian Kent
cfaf86ab6c autofs: use path_is_mountpoint() to fix unreliable d_mountpoint() checks
If an automount mount is clone(2)ed into a file system that is propagation
private, when it later expires in the originating namespace, subsequent
calls to autofs ->d_automount() for that dentry in the original namespace
will return ELOOP until the mount is umounted in the cloned namespace.

Now that a struct path is available where needed use path_is_mountpoint()
instead of d_mountpoint() so we don't get false positives when checking if
a dentry is a mount point in the current namespace.

Link: http://lkml.kernel.org/r/20161011053418.27645.15241.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-03 20:51:48 -05:00
Ian Kent
dd36a882e7 autofs: change autofs4_wait() to take struct path
In order to use the functions path_is_mountpoint() and path_has_submounts()
autofs needs to pass a struct path in several places.

Now change autofs4_wait() to take a struct path instead of a struct
dentry.

Link: http://lkml.kernel.org/r/20161011053413.27645.84666.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-03 20:51:48 -05:00
Ian Kent
74f504cff5 autofs: change autofs4_expire_wait()/do_expire_wait() to take struct path
In order to use the functions path_is_mountpoint() and path_has_submounts()
autofs needs to pass a struct path in several places.

Start by changing autofs4_expire_wait() and do_expire_wait() to take
a struct path instead of a struct dentry.

Link: http://lkml.kernel.org/r/20161011053408.27645.40091.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-03 20:51:47 -05:00
Ian Kent
fb5f51c742 vfs: change d_manage() to take a struct path
For the autofs module to be able to reliably check if a dentry is a
mountpoint in a multiple namespace environment the ->d_manage() dentry
operation will need to take a path argument instead of a dentry.

Link: http://lkml.kernel.org/r/20161011053352.27645.83962.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-02 22:15:53 -05:00
Tomohiro Kusumi
fcc24534b0 autofs: refactor ioctl fn vector in iookup_dev_ioctl()
cmd part of this struct is the same as an index of itself within
_ioctls[]. In fact this cmd is unused, so we can drop this part.

Link: http://lkml.kernel.org/r/20160831033414.9910.66697.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Tomohiro Kusumi
962ca7cfbd autofs: remove possibly misleading /* #define DEBUG */
Having this in autofs_i.h gives illusion that uncommenting this enables
pr_debug(), but it doesn't enable all the pr_debug() in autofs because
inclusion order matters.

XFS has the same DEBUG macro in its core header fs/xfs/xfs.h, however XFS
seems to have a rule to include this prior to other XFS headers as well as
kernel headers.  This is not the case with autofs, and DEBUG could be
enabled via Makefile, so autofs should just get rid of this comment to
make the code less confusing.  It's a comment, so there is literally no
functional difference.

Link: http://lkml.kernel.org/r/20160831033409.9910.77067.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Tomohiro Kusumi
390855547c autofs: fix print format for ioctl warning message
All other warnings use "cmd(0x%08x)" and this is the only one with
"cmd(%d)".  (below comes from my userspace debug program, but not
automount daemon)

[ 1139.905676] autofs4:pid:1640:check_dev_ioctl_version: ioctl control interface version mismatch: kernel(1.0), user(0.0), cmd(-1072131215)

Link: http://lkml.kernel.org/r/20160812024851.12352.75458.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Ian Kent
d9e1923207 autofs: add autofs_dev_ioctl_version() for AUTOFS_DEV_IOCTL_VERSION_CMD
No functional changes, based on the following justification.

1. Make the code more consistent using the ioctl vector _ioctls[],
   rather than assigning NULL only for this ioctl command.
2. Remove goto done; for better maintainability in the long run.
3. The existing code is based on the fact that validate_dev_ioctl()
   sets ioctl version for any command, but AUTOFS_DEV_IOCTL_VERSION_CMD
   should explicitly set it regardless of the default behavior.

Link: http://lkml.kernel.org/r/20160812024846.12352.9885.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Ian Kent
aa8419367b autofs: fix dev ioctl number range check
The count of miscellaneous device ioctls in fs/autofs4/autofs_i.h is wrong.

The number of ioctls is the difference between AUTOFS_DEV_IOCTL_VERSION_CMD
and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD (14) not the difference between
AUTOFS_IOC_COUNT and 11 (21).

[kusumi.tomohiro@gmail.com: fix typo that made the count macro negative]
 Link: http://lkml.kernel.org/r/20160831033420.9910.16809.stgit@pluto.themaw.net
Link: http://lkml.kernel.org/r/20160812024841.12352.11975.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Tomohiro Kusumi
b6e3795a06 autofs: fix pr_debug() message
This isn't a return value, so change the message to indicate the status is
the result of may_umount().

(or locate pr_debug() after put_user() with the same message)

Link: http://lkml.kernel.org/r/20160812024836.12352.74628.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Tomohiro Kusumi
41a4497a4f autofs: don't fail to free_dev_ioctl(param)
Returning -ENOTTY here fails to free dynamically allocated param.

Link: http://lkml.kernel.org/r/20160812024815.12352.69153.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Tomohiro Kusumi
eea618e6d5 autofs: remove obsolete sb fields
These two were left from commit aa55ddf340 ("autofs4: remove unused
ioctls") which removed unused ioctls.

Link: http://lkml.kernel.org/r/20160812024810.12352.96377.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <ikent@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Tomohiro Kusumi
ca552599bf autofs: use autofs4_free_ino() to kfree dentry data
kfree dentry data allocated by autofs4_new_ino() with autofs4_free_ino()
instead of raw kfree.  (since we have the interface to free autofs_info*)

This patch was modified to remove the need to set the dentry info field to
NULL dew to a change in the previous patch.

Link: http://lkml.kernel.org/r/20160812024805.12352.43650.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Ian Kent
1574fa7beb autofs: remove ino free in autofs4_dir_symlink()
The inode allocation failure case in autofs4_dir_symlink() frees the
autofs dentry info of the dentry without setting ->d_fsdata to NULL.

That could lead to a double free so just get rid of the free and leave it
to ->d_release().

Link: http://lkml.kernel.org/r/20160812024759.12352.10653.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Tomohiro Kusumi
97537b35b6 autofs: add WARN_ON(1) for non dir/link inode case
It's invalid if the given mode is neither dir nor link, so warn on else
case.

Link: http://lkml.kernel.org/r/20160812024754.12352.8536.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Ian Kent
1973a12269 autofs: fix autofs4_fill_super() error exit handling
Somewhere along the line the error handling gotos have become incorrect.

Link: http://lkml.kernel.org/r/20160812024749.12352.15100.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Tomohiro Kusumi
749800ef53 autofs: test autofs versions first on sb initialization
This patch does what the below comment says.  It could be and it's
considered better to do this first before various functions get called
during initialization.

/* Couldn't this be tested earlier? */

Link: http://lkml.kernel.org/r/20160812024744.12352.43075.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Tomohiro Kusumi
4a44c1859f autofs: drop unnecessary extern in autofs_i.h
autofs4_kill_sb() doesn't need to be declared as extern, and no other
functions in .h are explicitly declared as extern.

Link: http://lkml.kernel.org/r/20160812024739.12352.99354.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:31 -07:00
Linus Torvalds
101105b171 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 ">rename2() work from Miklos + current_time() from Deepa"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Replace current_fs_time() with current_time()
  fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
  fs: Replace CURRENT_TIME with current_time() for inode timestamps
  fs: proc: Delete inode time initializations in proc_alloc_inode()
  vfs: Add current_time() api
  vfs: add note about i_op->rename changes to porting
  fs: rename "rename2" i_op to "rename"
  vfs: remove unused i_op->rename
  fs: make remaining filesystems use .rename2
  libfs: support RENAME_NOREPLACE in simple_rename()
  fs: support RENAME_NOREPLACE for local filesystems
  ncpfs: fix unused variable warning
2016-10-10 20:16:43 -07:00
Al Viro
3873691e5a Merge remote-tracking branch 'ovl/rename2' into for-linus 2016-10-10 23:02:51 -04:00
Linus Torvalds
14986a34e1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman:
 "This set of changes is a number of smaller things that have been
  overlooked in other development cycles focused on more fundamental
  change. The devpts changes are small things that were a distraction
  until we managed to kill off DEVPTS_MULTPLE_INSTANCES. There is an
  trivial regression fix to autofs for the unprivileged mount changes
  that went in last cycle. A pair of ioctls has been added by Andrey
  Vagin making it is possible to discover the relationships between
  namespaces when referring to them through file descriptors.

  The big user visible change is starting to add simple resource limits
  to catch programs that misbehave. With namespaces in general and user
  namespaces in particular allowing users to use more kinds of
  resources, it has become important to have something to limit errant
  programs. Because the purpose of these limits is to catch errant
  programs the code needs to be inexpensive to use as it always on, and
  the default limits need to be high enough that well behaved programs
  on well behaved systems don't encounter them.

  To this end, after some review I have implemented per user per user
  namespace limits, and use them to limit the number of namespaces. The
  limits being per user mean that one user can not exhause the limits of
  another user. The limits being per user namespace allow contexts where
  the limit is 0 and security conscious folks can remove from their
  threat anlysis the code used to manage namespaces (as they have
  historically done as it root only). At the same time the limits being
  per user namespace allow other parts of the system to use namespaces.

  Namespaces are increasingly being used in application sand boxing
  scenarios so an all or nothing disable for the entire system for the
  security conscious folks makes increasing use of these sandboxes
  impossible.

  There is also added a limit on the maximum number of mounts present in
  a single mount namespace. It is nontrivial to guess what a reasonable
  system wide limit on the number of mount structure in the kernel would
  be, especially as it various based on how a system is using
  containers. A limit on the number of mounts in a mount namespace
  however is much easier to understand and set. In most cases in
  practice only about 1000 mounts are used. Given that some autofs
  scenarious have the potential to be 30,000 to 50,000 mounts I have set
  the default limit for the number of mounts at 100,000 which is well
  above every known set of users but low enough that the mount hash
  tables don't degrade unreaonsably.

  These limits are a start. I expect this estabilishes a pattern that
  other limits for resources that namespaces use will follow. There has
  been interest in making inotify event limits per user per user
  namespace as well as interest expressed in making details about what
  is going on in the kernel more visible"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (28 commits)
  autofs:  Fix automounts by using current_real_cred()->uid
  mnt: Add a per mount namespace limit on the number of mounts
  netns: move {inc,dec}_net_namespaces into #ifdef
  nsfs: Simplify __ns_get_path
  tools/testing: add a test to check nsfs ioctl-s
  nsfs: add ioctl to get a parent namespace
  nsfs: add ioctl to get an owning user namespace for ns file descriptor
  kernel: add a helper to get an owning user namespace for a namespace
  devpts: Change the owner of /dev/pts/ptmx to the mounter of /dev/pts
  devpts: Remove sync_filesystems
  devpts: Make devpts_kill_sb safe if fsi is NULL
  devpts: Simplify devpts_mount by using mount_nodev
  devpts: Move the creation of /dev/pts/ptmx into fill_super
  devpts: Move parse_mount_options into fill_super
  userns: When the per user per user namespace limit is reached return ENOSPC
  userns; Document per user per user namespace limits.
  mntns: Add a limit on the number of mount namespaces.
  netns: Add a limit on the number of net namespaces
  cgroupns: Add a limit on the number of cgroup namespaces
  ipcns: Add a  limit on the number of ipc namespaces
  ...
2016-10-06 09:52:23 -07:00
Eric W. Biederman
069d5ac9ae autofs: Fix automounts by using current_real_cred()->uid
Seth Forshee reports that in 4.8-rcN some automounts are failing
because the requesting the automount changed.

The relevant call path is:
follow_automount()
    ->d_automount
    autofs4_d_automount
       autofs4_mount_wait
           autofs4_wait

In autofs4_wait wq_uid and wq_gid are set to current_uid() and
current_gid respectively.  With follow_automount now overriding creds
uid that we export to userspace changes and that breaks existing
setups.

To remove the regression set wq_uid and wq_gid from
current_real_cred()->uid and current_real_cred()->gid respectively.
This restores the current behavior as current->real_cred is identical
to current->cred except when override creds are used.

Cc: stable@vger.kernel.org
Fixes: aeaa4a79ff ("fs: Call d_automount with the filesystems creds")
Reported-by: Seth Forshee <seth.forshee@canonical.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-09-30 12:48:01 -05:00
Deepa Dinamani
078cd8279e fs: Replace CURRENT_TIME with current_time() for inode timestamps
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.

CURRENT_TIME is also not y2038 safe.

This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.

Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Felipe Balbi <balbi@kernel.org>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27 21:06:21 -04:00
Ian Kent
7cbdb4a286 autofs: use dentry flags to block walks during expire
Somewhere along the way the autofs expire operation has changed to hold
a spin lock over expired dentry selection.  The autofs indirect mount
expired dentry selection is complicated and quite lengthy so it isn't
appropriate to hold a spin lock over the operation.

Commit 47be61845c ("fs/dcache.c: avoid soft-lockup in dput()") added a
might_sleep() to dput() causing a WARN_ONCE() about this usage to be
issued.

But the spin lock doesn't need to be held over this check, the autofs
dentry info.  flags are enough to block walks into dentrys during the
expire.

I've left the direct mount expire as it is (for now) because it is much
simpler and quicker than the indirect mount expire and adding spin lock
release and re-aquires would do nothing more than add overhead.

Fixes: 47be61845c ("fs/dcache.c: avoid soft-lockup in dput()")
Link: http://lkml.kernel.org/r/20160912014017.1773.73060.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Reported-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Takashi Iwai <tiwai@suse.de>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-19 15:36:17 -07:00
Linus Torvalds
835c92d43b Merge branch 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull qstr constification updates from Al Viro:
 "Fairly self-contained bunch - surprising lot of places passes struct
  qstr * as an argument when const struct qstr * would suffice; it
  complicates analysis for no good reason.

  I'd prefer to feed that separately from the assorted fixes (those are
  in #for-linus and with somewhat trickier topology)"

* 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  qstr: constify instances in adfs
  qstr: constify instances in lustre
  qstr: constify instances in f2fs
  qstr: constify instances in ext2
  qstr: constify instances in vfat
  qstr: constify instances in procfs
  qstr: constify instances in fuse
  qstr constify instances in fs/dcache.c
  qstr: constify instances in nfs
  qstr: constify instances in ocfs2
  qstr: constify instances in autofs4
  qstr: constify instances in hfs
  qstr: constify instances in hfsplus
  qstr: constify instances in logfs
  qstr: constify dentry_init_security
2016-08-06 09:49:02 -04:00
Linus Torvalds
554828ee0d Merge branch 'salted-string-hash'
This changes the vfs dentry hashing to mix in the parent pointer at the
_beginning_ of the hash, rather than at the end.

That actually improves both the hash and the code generation, because we
can move more of the computation to the "static" part of the dcache
setup, and do less at lookup runtime.

It turns out that a lot of other hash users also really wanted to mix in
a base pointer as a 'salt' for the hash, and so the slightly extended
interface ends up working well for other cases too.

Users that want a string hash that is purely about the string pass in a
'salt' pointer of NULL.

* merge branch 'salted-string-hash':
  fs/dcache.c: Save one 32-bit multiply in dcache lookup
  vfs: make the string hashes salt the hash
2016-07-28 12:26:31 -07:00
Al Viro
8ac790f312 qstr: constify instances in autofs4
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-20 23:30:06 -04:00
Andrey Vagin
5a9294e5c5 autofs: don't get stuck in a loop if vfs_write() returns an error
__vfs_write() returns a negative value in a error case.

Link: http://lkml.kernel.org/r/20160616083108.6278.65815.stgit@pluto.themaw.net
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-24 17:23:52 -07:00
Al Viro
ea01a18494 autofs races
* make autofs4_expire_indirect() skip the dentries being in process of
expiry
* do *not* mess with list_move(); making sure that dentry with
AUTOFS_INF_EXPIRING are not picked for expiry is enough.
* do not remove NO_RCU when we set EXPIRING, don't bother with smp_mb()
there.  Clear it at the same time we clear EXPIRING.  Makes a bunch of
tests simpler.
* rename NO_RCU to WANT_EXPIRE, which is what it really is.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-12 11:24:46 -04:00
Linus Torvalds
8387ff2577 vfs: make the string hashes salt the hash
We always mixed in the parent pointer into the dentry name hash, but we
did it late at lookup time.  It turns out that we can simplify that
lookup-time action by salting the hash with the parent pointer early
instead of late.

A few other users of our string hashes also wanted to mix in their own
pointers into the hash, and those are updated to use the same mechanism.

Hash users that don't have any particular initial salt can just use the
NULL pointer as a no-salt.

Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-10 20:21:46 -07:00
Al Viro
4e82901cd6 dcache_{readdir,dir_lseek}() users: switch to ->iterate_shared
no need to lock directory in dcache_dir_lseek(), while we are
at it - per-struct file exclusion is enough.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:32 -04:00
Linus Torvalds
3c2de27d79 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:

 - Preparations of parallel lookups (the remaining main obstacle is the
   need to move security_d_instantiate(); once that becomes safe, the
   rest will be a matter of rather short series local to fs/*.c

 - preadv2/pwritev2 series from Christoph

 - assorted fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits)
  splice: handle zero nr_pages in splice_to_pipe()
  vfs: show_vfsstat: do not ignore errors from show_devname method
  dcache.c: new helper: __d_add()
  don't bother with __d_instantiate(dentry, NULL)
  untangle fsnotify_d_instantiate() a bit
  uninline d_add()
  replace d_add_unique() with saner primitive
  quota: use lookup_one_len_unlocked()
  cifs_get_root(): use lookup_one_len_unlocked()
  nfs_lookup: don't bother with d_instantiate(dentry, NULL)
  kill dentry_unhash()
  ceph_fill_trace(): don't bother with d_instantiate(dn, NULL)
  autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup()
  configfs: move d_rehash() into configfs_create() for regular files
  ceph: don't bother with d_rehash() in splice_dentry()
  namei: teach lookup_slow() to skip revalidate
  namei: massage lookup_slow() to be usable by lookup_one_len_unlocked()
  lookup_one_len_unlocked(): use lookup_dcache()
  namei: simplify invalidation logics in lookup_dcache()
  namei: change calling conventions for lookup_{fast,slow} and follow_managed()
  ...
2016-03-19 18:52:29 -07:00
Ian Kent
8a78d59304 autofs4: use pr_xxx() macros directly for logging
Use the standard pr_xxx() log macros directly for log prints instead of
the AUTOFS_XXX() macros.

Signed-off-by: Ian Kent <ikent@redhat.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
90967c87e3 autofs4: change log print macros to not insert newline
Common kernel coding practice is to include the newline of log prints
within the log text rather than hidden away in a macro.

To avoid introducing inconsistencies as changes are made change the log
macros to not include the newline.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
cab49f9ed8 autofs4: make autofs log prints consistent
Use the pr_*() print in AUTOFS_*() macros instead of printks and include
the module name in log message macros.  Also use the AUTOFS_*() macros
everywhere instead of raw printks.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
0266725ad4 autofs4: fix some white space errors
Fix some white space format errors.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
e3cd8067c1 autofs4: fix invalid ioctl return in autofs4_root_ioctl_unlocked()
The return from an ioctl if an invalid ioctl is passed in should be
EINVAL not ENOSYS.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
b3f67a988c autofs4: fix coding style line length in autofs4_wait()
The need for this is questionable but checkpatch.pl complains about the
line length and it's a straightfoward change.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
aa330ddc53 autofs4: fix coding style problem in autofs4_get_set_timeout()
Refactor autofs4_get_set_timeout() to eliminate coding style error.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Ian Kent
e9a7c2f1a5 autofs4: coding style fixes
Try and make the coding style completely consistent throughtout the
autofs module and inline with kernel coding style recommendations.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Stanislav Kinsburskiy
c83aa55d0b autofs: show pipe inode in mount options
This is required for CRIU (Checkpoint Restart In Userspace) to migrate a
mount point when write end in user space is closed.

Below is a brief description of the problem.

To migrate a non-catatonic autofs mount point, one has to restore the
control pipe between kernel and autofs master process.

One of the autofs masters is systemd, which closes pipe write end after
passing it to the kernel with mount call.

To be able to restore the systemd control pipe one has to know which
read pipe end in systemd corresponds to the write pipe end in the
kernel.  The pipe "fd" in mount options is not enough because it was
closed and probably replaced by some other descriptor.

Thus, some other attribute is required to be able to find the read pipe
end.  The best attribute to use to find the correct pipe end is inode
number becuase it's unique for the whole system and can't be reused
while the autofs mount exists.

This attribute can also be used to recognize a situation where an autofs
mount has no master (no process with specified "pgrp" or no file
descriptor with "pipe_ino", specified in autofs mount options).

Signed-off-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 16:55:16 -07:00
Al Viro
de4acda16e autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-14 00:16:00 -04:00
Al Viro
fceef393a5 switch ->get_link() to delayed_call, kill ->put_link()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-30 13:01:03 -05:00
Al Viro
6b2553918d replace ->follow_link() with new method that could stay in RCU mode
new method: ->get_link(); replacement of ->follow_link().  The differences
are:
	* inode and dentry are passed separately
	* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
	* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.

It's a flagday change - the old method is gone, all in-tree instances
converted.  Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode.  That'll change
in the next commits.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-08 22:41:54 -05:00
Al Viro
dc3f4198ea make simple_positive() public
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:02:01 -04:00
Al Viro
6e77137b36 don't pass nameidata to ->follow_link()
its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidata

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:20:15 -04:00
Al Viro
680baacbca new ->follow_link() and ->put_link() calling conventions
a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body.  Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks.  Stored pointer
is ignored in all cases except the last one.

Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().

b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is.  In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:19:45 -04:00
David Howells
2b0143b5c9 VFS: normal filesystems (and lustre): d_inode() annotations
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
Al Viro
a35fb914ae autofs: switch to __vfs_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:37 -04:00