litmus2008.git/fs/hugetlbfs, branch master

hugetlb: allow bulk updating in hugetlb_*_quota()

2007-11-15T02:45:40+00:00

Add a second parameter 'delta' to hugetlb_get_quota and hugetlb_put_quota to
allow bulk updating of the sbinfo->free_blocks counter.  This will be used by
the next patch in the series.

Signed-off-by: Adam Litke 
Cc: Ken Chen 
Cc: Andy Whitcroft 
Cc: Dave Hansen 
Cc: David Gibson 
Cc: William Lee Irwin III 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlb: fix quota management for private mappings

2007-11-15T02:45:40+00:00

The hugetlbfs quota management system was never taught to handle MAP_PRIVATE
mappings when that support was added.  Currently, quota is debited at page
instantiation and credited at file truncation.  This approach works correctly
for shared pages but is incomplete for private pages.  In addition to
hugetlb_no_page(), private pages can be instantiated by hugetlb_cow(); but
this function does not respect quotas.

Private huge pages are treated very much like normal, anonymous pages.  They
are not "backed" by the hugetlbfs file and are not stored in the mapping's
radix tree.  This means that private pages are invisible to
truncate_hugepages() so that function will not credit the quota.

This patch (based on a prototype provided by Ken Chen) moves quota crediting
for all pages into free_huge_page().  page->private is used to store a pointer
to the mapping to which this page belongs.  This is used to credit quota on
the appropriate hugetlbfs instance.

Signed-off-by: Adam Litke 
Cc: Ken Chen 
Cc: Ken Chen 
Cc: Andy Whitcroft 
Cc: Dave Hansen 
Cc: David Gibson 
Cc: William Lee Irwin III 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

r/o bind mounts: filesystem helpers for custom 'struct file's

2007-10-17T15:43:04+00:00

Why do we need r/o bind mounts?

This feature allows a read-only view into a read-write filesystem.  In the
process of doing that, it also provides infrastructure for keeping track of
the number of writers to any given mount.

This has a number of uses.  It allows chroots to have parts of filesystems
writable.  It will be useful for containers in the future because users may
have root inside a container, but should not be allowed to write to
somefilesystems.  This also replaces patches that vserver has had out of the
tree for several years.

It allows security enhancement by making sure that parts of your filesystem
read-only (such as when you don't trust your FTP server), when you don't want
to have entire new filesystems mounted, or when you want atime selectively
updated.  I've been using the following script to test that the feature is
working as desired.  It takes a directory and makes a regular bind and a r/o
bind mount of it.  It then performs some normal filesystem operations on the
three directories, including ones that are expected to fail, like creating a
file on the r/o mount.

This patch:

Some filesystems forego the vfs and may_open() and create their own 'struct
file's.

This patch creates a couple of helper functions which can be used by these
filesystems, and will provide a unified place which the r/o bind mount code
may patch.

Also, rename an existing, static-scope init_file() to a less generic name.

Signed-off-by: Dave Hansen 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

introduce I_SYNC

2007-10-17T15:43:02+00:00

I_LOCK was used for several unrelated purposes, which caused deadlock
situations in certain filesystems as a side effect.  One of the purposes
now uses the new I_SYNC bit.

Also document the various bits and change their order from historical to
logical.

[bunk@stusta.de: make fs/inode.c:wake_up_inode() static]
Signed-off-by: Joern Engel 
Cc: Dave Kleikamp 
Cc: David Chinner 
Cc: Anton Altaparmakov 
Cc: Al Viro 
Cc: Christoph Hellwig 
Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Slab API: remove useless ctor parameter and reorder parameters

2007-10-17T15:42:45+00:00

Slab constructors currently have a flags parameter that is never used.  And
the order of the arguments is opposite to other slab functions.  The object
pointer is placed before the kmem_cache pointer.

Convert

        ctor(void *object, struct kmem_cache *s, unsigned long flags)

to

        ctor(struct kmem_cache *s, void *object)

throughout the kernel

[akpm@linux-foundation.org: coupla fixes]
Signed-off-by: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: bdi init hooks

2007-10-17T15:42:45+00:00

provide BDI constructor/destructor hooks

[akpm@linux-foundation.org: compile fix]
Signed-off-by: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlbfs read() support

2007-10-16T16:43:03+00:00

Support for reading from hugetlbfs files.  libhugetlbfs lets application
text/data to be placed in large pages.  When we do that, oprofile doesn't
work - since libbfd tries to read from it.

This code is very similar to what do_generic_mapping_read() does, but I
can't use it since it has PAGE_CACHE_SIZE assumptions.

[akpm@linux-foundation.org: cleanups, fix leak]
[bunk@stusta.de: make hugetlbfs_read() static]
Signed-off-by: Badari Pulavarty 
Acked-by: William Irwin 
Tested-by: Nishanth Aravamudan 
Cc: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugetlb: allow extending ftruncate on hugetlbfs

2007-10-16T16:43:02+00:00

For historical reason, expanding ftruncate that increases file size on
hugetlbfs is not allowed due to pages were pre-faulted and lack of fault
handler.  Now that we have demand faulting on hugetlb since 2.6.15, there
is no reason to hold back that limitation.

This will make hugetlbfs behave more like a normal fs.  I'm writing a user
level code that uses hugetlbfs but will fall back to tmpfs if there are no
hugetlb page available in the system.  Having hugetlbfs specific ftruncate
behavior is a bit quirky and I would like to remove that artificial
limitation.

Signed-off-by: 
Acked-by: Wiliam Irwin 
Cc: Adam Litke 
Cc: David Gibson 
Cc: Nishanth Aravamudan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

implement simple fs aops

2007-10-16T16:42:55+00:00

Implement new aops for some of the simpler filesystems.

Signed-off-by: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hugepage: fix broken check for offset alignment in hugepage mappings

2007-08-31T08:42:23+00:00

For hugepage mappings, the file offset, like the address and size, needs to
be aligned to the size of a hugepage.

In commit 68589bc353037f233fe510ad9ff432338c95db66, the check for this was
moved into prepare_hugepage_range() along with the address and size checks.
 But since BenH's rework of the get_unmapped_area() paths leading up to
commit 4b1d89290b62bb2db476c94c82cf7442aab440c8, prepare_hugepage_range()
is only called for MAP_FIXED mappings, not for other mappings.  This means
we're no longer ever checking for an aligned offset - I've confirmed that
mmap() will (apparently) succeed with a misaligned offset on both powerpc
and i386 at least.

This patch restores the check, removing it from prepare_hugepage_range()
and putting it back into hugetlbfs_file_mmap().  I'm putting it there,
rather than in the get_unmapped_area() path so it only needs to go in one
place, than separately in the half-dozen or so arch-specific
implementations of hugetlb_get_unmapped_area().

Signed-off-by: David Gibson 
Cc: Adam Litke 
Cc: Andi Kleen 
Cc: "David S. Miller" 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds