linux-toradex.git/fs/locks.c, branch v4.7

locks: use file_inode()

2016-07-01T14:24:18+00:00

(Another one for the f_path debacle.)

ltp fcntl33 testcase caused an Oops in selinux_file_send_sigiotask.

The reason is that generic_add_lease() used filp->f_path.dentry->inode
while all the others use file_inode().  This makes a difference for files
opened on overlayfs since the former will point to the overlay inode the
latter to the underlying inode.

So generic_add_lease() added the lease to the overlay inode and
generic_delete_lease() removed it from the underlying inode.  When the file
was released the lease remained on the overlay inode's lock list, resulting
in use after free.

Reported-by: Eryu Guan 
Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Cc: 
Signed-off-by: Miklos Szeredi 
Reviewed-by: Jeff Layton 
Signed-off-by: J. Bruce Fields

wrappers for ->i_mutex access

2016-01-22T23:04:28+00:00

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: Al Viro

Merge branch 'work.copy_file_range' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-01-13T00:30:34+00:00

Pull vfs copy_file_range updates from Al Viro:
 "Several series around copy_file_range/CLONE"

* 'work.copy_file_range' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  btrfs: use new dedupe data function pointer
  vfs: hoist the btrfs deduplication ioctl to the vfs
  vfs: wire up compat ioctl for CLONE/CLONE_RANGE
  cifs: avoid unused variable and label
  nfsd: implement the NFSv4.2 CLONE operation
  nfsd: Pass filehandle to nfs4_preprocess_stateid_op()
  vfs: pull btrfs clone API to vfs layer
  locks: new locks_mandatory_area calling convention
  vfs: Add vfs_copy_file_range() support for pagecache copies
  btrfs: add .copy_file_range file operation
  x86: add sys_copy_file_range to syscall tables
  vfs: add copy_file_range syscall and vfs helper

locks: rename __posix_lock_file to posix_lock_inode

2016-01-08T16:38:30+00:00

...a more descriptive name and we can drop the double underscore prefix.

Signed-off-by: Jeff Layton 
Acked-by: "J. Bruce Fields"

locks: prink more detail when there are leaked locks

2016-01-08T16:38:25+00:00

Right now, we just get WARN_ON_ONCE, which is not particularly helpful.
Have it dump some info about the locks and the inode to make it easier
to track down leaked locks in the future.

Signed-off-by: Jeff Layton 
Acked-by: "J. Bruce Fields"

locks: pass inode pointer to locks_free_lock_context

2016-01-08T16:38:19+00:00

...so we can print information about it if there are leaked locks.

Signed-off-by: Jeff Layton 
Acked-by: "J. Bruce Fields"

locks: sprinkle some tracepoints around the file locking code

2016-01-08T16:38:13+00:00

Add some tracepoints around the POSIX locking code. These were useful
when tracking down problems when handling the race between setlk and
close.

Signed-off-by: Jeff Layton 
Acked-by: "J. Bruce Fields"

locks: don't check for race with close when setting OFD lock

2016-01-08T16:38:07+00:00

We don't clean out OFD locks on close(), so there's no need to check
for a race with them here. They'll get cleaned out at the same time
that flock locks are.

Signed-off-by: Jeff Layton 
Acked-by: "J. Bruce Fields"

locks: fix unlock when fcntl_setlk races with a close

2016-01-08T01:32:48+00:00

Dmitry reported that he was able to reproduce the WARN_ON_ONCE that
fires in locks_free_lock_context when the flc_posix list isn't empty.

The problem turns out to be that we're basically rebuilding the
file_lock from scratch in fcntl_setlk when we discover that the setlk
has raced with a close. If the l_whence field is SEEK_CUR or SEEK_END,
then we may end up with fl_start and fl_end values that differ from
when the lock was initially set, if the file position or length of the
file has changed in the interim.

Fix this by just reusing the same lock request structure, and simply
override fl_type value with F_UNLCK as appropriate. That ensures that
we really are unlocking the lock that was initially set.

While we're there, make sure that we do pop a WARN_ON_ONCE if the
removal ever fails. Also return -EBADF in this event, since that's
what we would have returned if the close had happened earlier.

Cc: Alexander Viro 
Cc: 
Fixes: c293621bbf67 (stale POSIX lock handling)
Reported-by: Dmitry Vyukov 
Signed-off-by: Jeff Layton 
Acked-by: "J. Bruce Fields"

fs: make locks.c explicitly non-modular

2015-12-18T12:05:06+00:00

The Kconfig currently controlling compilation of this code is:

config FILE_LOCKING
     bool "Enable POSIX file locking API" if EXPERT

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modularity so that when reading the
driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering gets bumped to one level earlier when we
use the more appropriate fs_initcall here.  However we've made similar
changes before without any fallout and none is expected here either.

Cc: Jeff Layton 
Acked-by: Jeff Layton 
Cc: "J. Bruce Fields" 
Cc: Alexander Viro 
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Paul Gortmaker 
Signed-off-by: Jeff Layton