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  1. 01 Mar, 2016 1 commit
  3. 22 Jan, 2016 1 commit
    • Al Viro's avatar
      wrappers for ->i_mutex access · 5955102c
      Al Viro authored 
      parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      5955102c
  5. 15 Jan, 2016 1 commit
    • Vladimir Davydov's avatar
      kmemcg: account certain kmem allocations to memcg · 5d097056
      Vladimir Davydov authored 
      Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg.  For the list, see below:

 - threadinfo
 - task_struct
 - task_delay_info
 - pid
 - cred
 - mm_struct
 - vm_area_struct and vm_region (nommu)
 - anon_vma and anon_vma_chain
 - signal_struct
 - sighand_struct
 - fs_struct
 - files_struct
 - fdtable and fdtable->full_fds_bits
 - dentry and external_name
 - inode for all filesystems. This is the most tedious part, because
   most filesystems overwrite the alloc_inode method.

The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds.  Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5d097056
  7. 14 Jan, 2016 2 commits
  9. 30 Dec, 2015 1 commit
  11. 09 Dec, 2015 1 commit
    • Al Viro's avatar
      replace ->follow_link() with new method that could stay in RCU mode · 6b255391
      Al Viro authored 
      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: default avatarAl Viro <viro@zeniv.linux.org.uk>
      6b255391
  13. 08 Dec, 2015 2 commits
    • Arnd Bergmann's avatar
      cifs: avoid unused variable and label · 8c36e9df
      Arnd Bergmann authored 
      The newly introduced cifs_clone_file_range() function produces
two harmless compile-time warnings:

cifsfs.c: In function 'cifs_clone_file_range':
cifsfs.c:963:1: warning: label 'out_unlock' defined but not used [-Wunused-label]
cifsfs.c:924:20: warning: unused variable 'src_tcon' [-Wunused-variable]

In both cases, removing the extraneous line avoids the warning.
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Fixes: c6f2a1e2e5f8 ("vfs: pull btrfs clone API to vfs layer")
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      8c36e9df
    • Christoph Hellwig's avatar
      vfs: pull btrfs clone API to vfs layer · 04b38d60
      Christoph Hellwig authored 
      The btrfs clone ioctls are now adopted by other file systems, with NFS
and CIFS already having support for them, and XFS being under active
development.  To avoid growth of various slightly incompatible
implementations, add one to the VFS.  Note that clones are different from
file copies in several ways:

 - they are atomic vs other writers
 - they support whole file clones
 - they support 64-bit legth clones
 - they do not allow partial success (aka short writes)
 - clones are expected to be a fast metadata operation

Because of that it would be rather cumbersome to try to piggyback them on
top of the recent clone_file_range infrastructure.  The converse isn't
true and the clone_file_range system call could try clone file range as
a first attempt to copy, something that further patches will enable.

Based on earlier work from Peng Tao.
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      04b38d60
  15. 09 Nov, 2015 1 commit
  17. 03 Nov, 2015 2 commits
  19. 12 Sep, 2015 1 commit
  21. 04 Sep, 2015 1 commit
    • Kees Cook's avatar
      fs: create and use seq_show_option for escaping · a068acf2
      Kees Cook authored 
      Many file systems that implement the show_options hook fail to correctly
escape their output which could lead to unescaped characters (e.g.  new
lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files.  This
could lead to confusion, spoofed entries (resulting in things like
systemd issuing false d-bus "mount" notifications), and who knows what
else.  This looks like it would only be the root user stepping on
themselves, but it's possible weird things could happen in containers or
in other situations with delegated mount privileges.

Here's an example using overlay with setuid fusermount trusting the
contents of /proc/mounts (via the /etc/mtab symlink).  Imagine the use
of "sudo" is something more sneaky:

  $ BASE="ovl"
  $ MNT="$BASE/mnt"
  $ LOW="$BASE/lower"
  $ UP="$BASE/upper"
  $ WORK="$BASE/work/ 0 0
  none /proc fuse.pwn user_id=1000"
  $ mkdir -p "$LOW" "$UP" "$WORK"
  $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt
  $ cat /proc/mounts
  none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0
  none /proc fuse.pwn user_id=1000 0 0
  $ fusermount -u /proc
  $ cat /proc/mounts
  cat: /proc/mounts: No such file or directory

This fixes the problem by adding new seq_show_option and
seq_show_option_n helpers, and updating the vulnerable show_option
handlers to use them as needed.  Some, like SELinux, need to be open
coded due to unusual existing escape mechanisms.

[akpm@linux-foundation.org: add lost chunk, per Kees]
[keescook@chromium.org: seq_show_option should be using const parameters]
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
Acked-by: default avatarJan Kara <jack@suse.com>
Acked-by: default avatarPaul Moore <paul@paul-moore.com>
Cc: J. R. Okajima <hooanon05g@gmail.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a068acf2
  23. 11 May, 2015 1 commit
  25. 15 Apr, 2015 1 commit
  27. 12 Apr, 2015 1 commit
  29. 19 Nov, 2014 1 commit
  31. 07 Oct, 2014 1 commit
    • Jeff Layton's avatar
      locks: plumb a "priv" pointer into the setlease routines · e6f5c789
      Jeff Layton authored 
      In later patches, we're going to add a new lock_manager_operation to
finish setting up the lease while still holding the i_lock.  To do
this, we'll need to pass a little bit of info in the fcntl setlease
case (primarily an fasync structure). Plumb the extra pointer into
there in advance of that.

We declare this pointer as a void ** to make it clear that this is
private info, and that the caller isn't required to set this unless
the lm_setup specifically requires it.
Signed-off-by: default avatarJeff Layton <jlayton@primarydata.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      e6f5c789
  33. 17 Aug, 2014 1 commit
  35. 16 Aug, 2014 1 commit
  37. 07 Aug, 2014 1 commit
  39. 19 Jun, 2014 1 commit
  41. 21 May, 2014 3 commits
  43. 06 May, 2014 3 commits
  45. 16 Apr, 2014 1 commit
    • Sachin Prabhu's avatar
      cifs: Wait for writebacks to complete before attempting write. · c11f1df5
      Sachin Prabhu authored 
      Problem reported in Red Hat bz 1040329 for strict writes where we cache
only when we hold oplock and write direct to the server when we don't.

When we receive an oplock break, we first change the oplock value for
the inode in cifsInodeInfo->oplock to indicate that we no longer hold
the oplock before we enqueue a task to flush changes to the backing
device. Once we have completed flushing the changes, we return the
oplock to the server.

There are 2 ways here where we can have data corruption
1) While we flush changes to the backing device as part of the oplock
break, we can have processes write to the file. These writes check for
the oplock, find none and attempt to write directly to the server.
These direct writes made while we are flushing from cache could be
overwritten by data being flushed from the cache causing data
corruption.
2) While a thread runs in cifs_strict_writev, the machine could receive
and process an oplock break after the thread has checked the oplock and
found that it allows us to cache and before we have made changes to the
cache. In that case, we end up with a dirty page in cache when we
shouldn't have any. This will be flushed later and will overwrite all
subsequent writes to the part of the file represented by this page.

Before making any writes to the server, we need to confirm that we are
not in the process of flushing data to the server and if we are, we
should wait until the process is complete before we attempt the write.
We should also wait for existing writes to complete before we process
an oplock break request which changes oplock values.

We add a version specific  downgrade_oplock() operation to allow for
differences in the oplock values set for the different smb versions.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Reviewed-by: default avatarPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      c11f1df5
  47. 03 Apr, 2014 2 commits
  49. 02 Apr, 2014 1 commit
  51. 13 Mar, 2014 1 commit
    • Theodore Ts'o's avatar
      fs: push sync_filesystem() down to the file system's remount_fs() · 02b9984d
      Theodore Ts'o authored 
      Previously, the no-op "mount -o mount /dev/xxx" operation when the
file system is already mounted read-write causes an implied,
unconditional syncfs().  This seems pretty stupid, and it's certainly
documented or guaraunteed to do this, nor is it particularly useful,
except in the case where the file system was mounted rw and is getting
remounted read-only.

However, it's possible that there might be some file systems that are
actually depending on this behavior.  In most file systems, it's
probably fine to only call sync_filesystem() when transitioning from
read-write to read-only, and there are some file systems where this is
not needed at all (for example, for a pseudo-filesystem or something
like romfs).
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Jan Kara <jack@suse.cz>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Anders Larsen <al@alarsen.net>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: xfs@oss.sgi.com
Cc: linux-btrfs@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: codalist@coda.cs.cmu.edu
Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: fuse-devel@lists.sourceforge.net
Cc: cluster-devel@redhat.com
Cc: linux-mtd@lists.infradead.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: linux-nfs@vger.kernel.org
Cc: linux-nilfs@vger.kernel.org
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: reiserfs-devel@vger.kernel.org
      02b9984d
  53. 25 Oct, 2013 1 commit
  55. 07 Oct, 2013 1 commit
    • Jan Klos's avatar
      cifs: Fix inability to write files >2GB to SMB2/3 shares · 2f6c9479
      Jan Klos authored 
      When connecting to SMB2/3 shares, maximum file size is set to non-LFS maximum in superblock. This is due to cap_large_files bit being different for SMB1 and SMB2/3 (where it is just an internal flag that is not negotiated and the SMB1 one corresponds to multichannel capability, so maybe LFS works correctly if server sends 0x08 flag) while capabilities are checked always for the SMB1 bit in cifs_read_super().

The patch fixes this by checking for the correct bit according to the protocol version.

CC: Stable <stable@kernel.org>
Signed-off-by: default avatarJan Klos <honza.klos@gmail.com>
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      2f6c9479
  57. 10 Sep, 2013 1 commit
  59. 08 Sep, 2013 2 commits
  61. 31 Jul, 2013 1 commit
    • Jeff Layton's avatar
      cifs: set sb->s_d_op before calling d_make_root() · 66ffd113
      Jeff Layton authored 
      Currently, the s_root dentry doesn't get its d_op pointer set to
anything. This breaks lookups in the root of case-insensitive mounts
since that relies on having d_hash and d_compare routines that know to
treat the filename as case-insensitive.

cifs.ko has been broken this way for a long time, but commit 1c929cfe
("switch cifs"), added a cryptic comment which is removed in the patch
below, which makes me wonder if this was done deliberately for some
reason. It's not clear to me why we'd want the s_root not to have d_op
set properly.

It may have something to do with d_automount or d_revalidate on the
root, but my suspicion in looking over the code is that Al was just
trying to preserve the existing behavior when changing this code over to
use s_d_op.

This patch changes it so that we set s_d_op before calling d_make_root
and removes the comment. I tested mounting, accessing and unmounting
several types of shares (including DFS referrals) and everything still
seemed to work OK afterward. I could be missing something however, so
please do let me know if I am.
Reported-by: default avatarJan-Marek Glogowski <glogow@fbihome.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      66ffd113
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