linux-toradex.git/fs/hugetlbfs, branch v2.6.32.58

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

2009-09-24T15:32:11+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  truncate: use new helpers
  truncate: new helpers
  fs: fix overflow in sys_mount() for in-kernel calls
  fs: Make unload_nls() NULL pointer safe
  freeze_bdev: grab active reference to frozen superblocks
  freeze_bdev: kill bd_mount_sem
  exofs: remove BKL from super operations
  fs/romfs: correct error-handling code
  vfs: seq_file: add helpers for data filling
  vfs: remove redundant position check in do_sendfile
  vfs: change sb->s_maxbytes to a loff_t
  vfs: explicitly cast s_maxbytes in fiemap_check_ranges
  libfs: return error code on failed attr set
  seq_file: return a negative error code when seq_path_root() fails.
  vfs: optimize touch_time() too
  vfs: optimization for touch_atime()
  vfs: split generic_forget_inode() so that hugetlbfs does not have to copy it
  fs/inode.c: add dev-id and inode number for debugging in init_special_inode()
  libfs: make simple_read_from_buffer conventional

hugetlbfs: do not call user_shm_lock() for MAP_HUGETLB fix

2009-09-24T14:20:56+00:00

Commit 6bfde05bf5c ("hugetlbfs: allow the creation of files suitable for
MAP_PRIVATE on the vfs internal mount") altered can_do_hugetlb_shm() to
check if a file is being created for shared memory or mmap().  If this
returns false, we then unconditionally call user_shm_lock() triggering a
warning.  This block should never be entered for MAP_HUGETLB.  This
patch partially reverts the problem and fixes the check.

Signed-off-by: Eric B Munson 
Cc: David Rientjes 
Cc: Mel Gorman 
Cc: Adam Litke 
Cc: David Gibson 
Cc: Lee Schermerhorn 
Cc: Nick Piggin 
Cc: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

vfs: split generic_forget_inode() so that hugetlbfs does not have to copy it

2009-09-24T11:47:25+00:00

Hugetlbfs needs to do special things instead of truncate_inode_pages().
 Currently, it copied generic_forget_inode() except for
truncate_inode_pages() call which is asking for trouble (the code there
isn't trivial).  So create a separate function generic_detach_inode()
which does all the list magic done in generic_forget_inode() and call
it from hugetlbfs_forget_inode().

Signed-off-by: Jan Kara 
Cc: Al Viro 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Al Viro

Move magic numbers into magic.h

2009-09-23T14:39:28+00:00

Move various magic-number definitions into magic.h.

Signed-off-by: Nick Black 
Acked-by: Pekka Enberg 
Cc: Al Viro 
Cc: "David S. Miller" 
Cc: Casey Schaufler 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlbfs: allow the creation of files suitable for MAP_PRIVATE on the vfs internal mount

2009-09-22T14:17:41+00:00

This patchset adds a flag to mmap that allows the user to request that an
anonymous mapping be backed with huge pages.  This mapping will borrow
functionality from the huge page shm code to create a file on the kernel
internal mount and use it to approximate an anonymous mapping.  The
MAP_HUGETLB flag is a modifier to MAP_ANONYMOUS and will not work without
both flags being preset.

A new flag is necessary because there is no other way to hook into huge
pages without creating a file on a hugetlbfs mount which wouldn't be
MAP_ANONYMOUS.

To userspace, this mapping will behave just like an anonymous mapping
because the file is not accessible outside of the kernel.

This patchset is meant to simplify the programming model.  Presently there
is a large chunk of boiler platecode, contained in libhugetlbfs, required
to create private, hugepage backed mappings.  This patch set would allow
use of hugepages without linking to libhugetlbfs or having hugetblfs
mounted.

Unification of the VM code would provide these same benefits, but it has
been resisted each time that it has been suggested for several reasons: it
would break PAGE_SIZE assumptions across the kernel, it makes page-table
abstractions really expensive, and it does not provide any benefit on
architectures that do not support huge pages, incurring fast path
penalties without providing any benefit on these architectures.

This patch:

There are two means of creating mappings backed by huge pages:

        1. mmap() a file created on hugetlbfs
        2. Use shm which creates a file on an internal mount which essentially
           maps it MAP_SHARED

The internal mount is only used for shared mappings but there is very
little that stops it being used for private mappings. This patch extends
hugetlbfs_file_setup() to deal with the creation of files that will be
mapped MAP_PRIVATE on the internal hugetlbfs mount. This extended API is
used in a subsequent patch to implement the MAP_HUGETLB mmap() flag.

Signed-off-by: Eric Munson 
Acked-by: David Rientjes 
Cc: Mel Gorman 
Cc: Adam Litke 
Cc: David Gibson 
Cc: Lee Schermerhorn 
Cc: Nick Piggin 
Cc: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

writeback: add name to backing_dev_info

2009-09-11T07:20:26+00:00

This enables us to track who does what and print info. Its main use
is catching dirty inodes on the default_backing_dev_info, so we can
fix that up.

Signed-off-by: Jens Axboe

mm: fix hugetlb bug due to user_shm_unlock call

2009-08-24T19:53:01+00:00

2.6.30's commit 8a0bdec194c21c8fdef840989d0d7b742bb5d4bc removed
user_shm_lock() calls in hugetlb_file_setup() but left the
user_shm_unlock call in shm_destroy().

In detail:
Assume that can_do_hugetlb_shm() returns true and hence user_shm_lock()
is not called in hugetlb_file_setup(). However, user_shm_unlock() is
called in any case in shm_destroy() and in the following
atomic_dec_and_lock(&up->__count) in free_uid() is executed and if
up->__count gets zero, also cleanup_user_struct() is scheduled.

Note that sched_destroy_user() is empty if CONFIG_USER_SCHED is not set.
However, the ref counter up->__count gets unexpectedly non-positive and
the corresponding structs are freed even though there are live
references to them, resulting in a kernel oops after a lots of
shmget(SHM_HUGETLB)/shmctl(IPC_RMID) cycles and CONFIG_USER_SCHED set.

Hugh changed Stefan's suggested patch: can_do_hugetlb_shm() at the
time of shm_destroy() may give a different answer from at the time
of hugetlb_file_setup().  And fixed newseg()'s no_id error path,
which has missed user_shm_unlock() ever since it came in 2.6.9.

Reported-by: Stefan Huber 
Signed-off-by: Hugh Dickins 
Tested-by: Stefan Huber 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds

Merge branch 'master' into next

2009-05-22T08:40:59+00:00

Conflicts:
	fs/exec.c

Removed IMA changes (the IMA checks are now performed via may_open()).

Signed-off-by: James Morris

integrity: move ima_counts_get

2009-05-21T23:45:33+00:00

Based on discussion on lkml (Andrew Morton and Eric Paris),
move ima_counts_get down a layer into shmem/hugetlb__file_setup().
Resolves drm shmem_file_setup() usage case as well.

HD comment:
  I still think you're doing this at the wrong level, but recognize
  that you probably won't be persuaded until a few more users of
  alloc_file() emerge, all wanting your ima_counts_get().

  Resolving GEM's shmem_file_setup() is an improvement, so I'll say

Acked-by: Hugh Dickins 
Signed-off-by: Mimi Zohar 
Signed-off-by: James Morris

Remove implementation of readpage from the hugetlbfs_aops

2009-05-13T15:04:45+00:00

The core VM assumes the page size used by the address_space in
inode->i_mapping is PAGE_SIZE but hugetlbfs breaks this assumption by
inserting pages into the page cache at offsets the core VM considers
unexpected.

This would not be a problem except that hugetlbfs also provide a
->readpage implementation.  As it exists, the core VM can assume the
base page size is being used, allocate pages on behalf of the
filesystem, insert them into the page cache and call ->readpage to
populate them.  These pages are the wrong size and at the wrong offset
for hugetlbfs causing confusion.

This patch deletes the ->readpage implementation for hugetlbfs on the
grounds the core VM should not be allocating and populating pages on
behalf of hugetlbfs.  There should be no existing users of the
->readpage implementation so it should not cause a regression.

Signed-off-by: Mel Gorman 
Signed-off-by: Linus Torvalds