29 Nov, 2007
1 commit
-
tmpfs was misconverted to __GFP_ZERO in 2.6.11. There's an unusual case in
which shmem_getpage receives the page from its caller instead of allocating.
We must cover this case by clear_highpage before SetPageUptodate, as before.Signed-off-by: Hugh Dickins
Signed-off-by: Linus Torvalds
30 Oct, 2007
1 commit
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It's possible to provoke unionfs (not yet in mainline, though in mm and
some distros) to hit shmem_writepage's BUG_ON(page_mapped(page)). I expect
it's possible to provoke the 2.6.23 ecryptfs in the same way (but the
2.6.24 ecryptfs no longer calls lower level's ->writepage).This came to light with the recent find that AOP_WRITEPAGE_ACTIVATE could
leak from tmpfs via write_cache_pages and unionfs to userspace. There's
already a fix (e423003028183df54f039dfda8b58c49e78c89d7 - writeback: don't
propagate AOP_WRITEPAGE_ACTIVATE) in the tree for that, and it's okay so
far as it goes; but insufficient because it doesn't address the underlying
issue, that shmem_writepage expects to be called only by vmscan (relying on
backing_dev_info capabilities to prevent the normal writeback path from
ever approaching it).That's an increasingly fragile assumption, and ramdisk_writepage (the other
source of AOP_WRITEPAGE_ACTIVATEs) is already careful to check
wbc->for_reclaim before returning it. Make the same check in
shmem_writepage, thereby sidestepping the page_mapped BUG also.Signed-off-by: Hugh Dickins
Cc: Erez Zadok
Cc:
Reviewed-by: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Oct, 2007
2 commits
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Now that nfsd has stopped writing to the find_exported_dentry member we an
mark the export_operations constSigned-off-by: Christoph Hellwig
Cc: Neil Brown
Cc: "J. Bruce Fields"
Cc:
Cc: Dave Kleikamp
Cc: Anton Altaparmakov
Cc: David Chinner
Cc: Timothy Shimmin
Cc: OGAWA Hirofumi
Cc: Hugh Dickins
Cc: Chris Mason
Cc: Jeff Mahoney
Cc: "Vladimir V. Saveliev"
Cc: Steven Whitehouse
Cc: Mark Fasheh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
I'm not sure what people were thinking when adding support to export tmpfs,
but here's the conversion anyway:Signed-off-by: Christoph Hellwig
Cc: Neil Brown
Cc: "J. Bruce Fields"
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Oct, 2007
9 commits
-
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 -
These aren't modular, so SLAB_PANIC is OK.
Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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 -
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 -
This patch makes three needlessly global functions static.
Signed-off-by: Adrian Bunk
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch marks a number of allocations that are either short-lived such as
network buffers or are reclaimable such as inode allocations. When something
like updatedb is called, long-lived and unmovable kernel allocations tend to
be spread throughout the address space which increases fragmentation.This patch groups these allocations together as much as possible by adding a
new MIGRATE_TYPE. The MIGRATE_RECLAIMABLE type is for allocations that can be
reclaimed on demand, but not moved. i.e. they can be migrated by deleting
them and re-reading the information from elsewhere.Signed-off-by: Mel Gorman
Cc: Andy Whitcroft
Cc: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Here's a cut at fixing up uses of the online node map in generic code.
mm/shmem.c:shmem_parse_mpol()
Ensure nodelist is subset of nodes with memory.
Use node_states[N_HIGH_MEMORY] as default for missing
nodelist for interleave policy.mm/shmem.c:shmem_fill_super()
initialize policy_nodes to node_states[N_HIGH_MEMORY]
mm/page-writeback.c:highmem_dirtyable_memory()
sum over nodes with memory
mm/page_alloc.c:zlc_setup()
allowednodes - use nodes with memory.
mm/page_alloc.c:default_zonelist_order()
average over nodes with memory.
mm/page_alloc.c:find_next_best_node()
skip nodes w/o memory.
N_HIGH_MEMORY state mask may not be initialized at this time,
unless we want to depend on early_calculate_totalpages() [see
below]. Will ZONE_MOVABLE ever be configurable?mm/page_alloc.c:find_zone_movable_pfns_for_nodes()
spread kernelcore over nodes with memory.
This required calling early_calculate_totalpages()
unconditionally, and populating N_HIGH_MEMORY node
state therein from nodes in the early_node_map[].
If we can depend on this, we can eliminate the
population of N_HIGH_MEMORY mask from __build_all_zonelists()
and use the N_HIGH_MEMORY mask in find_next_best_node().mm/mempolicy.c:mpol_check_policy()
Ensure nodes specified for policy are subset of
nodes with memory.[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Lee Schermerhorn
Acked-by: Christoph Lameter
Cc: Shaohua Li
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Implement new aops for some of the simpler filesystems.
Signed-off-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch cleans up duplicate includes in
mm/Signed-off-by: Jesper Juhl
Acked-by: Paul Mundt
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Jul, 2007
5 commits
-
Slab destructors were no longer supported after Christoph's
c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been
BUGs for both slab and slub, and slob never supported them
either.This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).Signed-off-by: Paul Mundt
-
This patch completes Linus's wish that the fault return codes be made into
bit flags, which I agree makes everything nicer. This requires requires
all handle_mm_fault callers to be modified (possibly the modifications
should go further and do things like fault accounting in handle_mm_fault --
however that would be for another patch).[akpm@linux-foundation.org: fix alpha build]
[akpm@linux-foundation.org: fix s390 build]
[akpm@linux-foundation.org: fix sparc build]
[akpm@linux-foundation.org: fix sparc64 build]
[akpm@linux-foundation.org: fix ia64 build]
Signed-off-by: Nick Piggin
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Cc: Russell King
Cc: Ian Molton
Cc: Bryan Wu
Cc: Mikael Starvik
Cc: David Howells
Cc: Yoshinori Sato
Cc: "Luck, Tony"
Cc: Hirokazu Takata
Cc: Geert Uytterhoeven
Cc: Roman Zippel
Cc: Greg Ungerer
Cc: Matthew Wilcox
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Heiko Carstens
Cc: Martin Schwidefsky
Cc: Paul Mundt
Cc: Kazumoto Kojima
Cc: Richard Curnow
Cc: William Lee Irwin III
Cc: "David S. Miller"
Cc: Jeff Dike
Cc: Paolo 'Blaisorblade' Giarrusso
Cc: Miles Bader
Cc: Chris Zankel
Acked-by: Kyle McMartin
Acked-by: Haavard Skinnemoen
Acked-by: Ralf Baechle
Acked-by: Andi Kleen
Signed-off-by: Andrew Morton
[ Still apparently needs some ARM and PPC loving - Linus ]
Signed-off-by: Linus Torvalds -
Change ->fault prototype. We now return an int, which contains
VM_FAULT_xxx code in the low byte, and FAULT_RET_xxx code in the next byte.
FAULT_RET_ code tells the VM whether a page was found, whether it has been
locked, and potentially other things. This is not quite the way he wanted
it yet, but that's changed in the next patch (which requires changes to
arch code).This means we no longer set VM_CAN_INVALIDATE in the vma in order to say
that a page is locked which requires filemap_nopage to go away (because we
can no longer remain backward compatible without that flag), but we were
going to do that anyway.struct fault_data is renamed to struct vm_fault as Linus asked. address
is now a void __user * that we should firmly encourage drivers not to use
without really good reason.The page is now returned via a page pointer in the vm_fault struct.
Signed-off-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Nonlinear mappings are (AFAIKS) simply a virtual memory concept that encodes
the virtual address -> file offset differently from linear mappings.->populate is a layering violation because the filesystem/pagecache code
should need to know anything about the virtual memory mapping. The hitch here
is that the ->nopage handler didn't pass down enough information (ie. pgoff).
But it is more logical to pass pgoff rather than have the ->nopage function
calculate it itself anyway (because that's a similar layering violation).Having the populate handler install the pte itself is likewise a nasty thing
to be doing.This patch introduces a new fault handler that replaces ->nopage and
->populate and (later) ->nopfn. Most of the old mechanism is still in place
so there is a lot of duplication and nice cleanups that can be removed if
everyone switches over.The rationale for doing this in the first place is that nonlinear mappings are
subject to the pagefault vs invalidate/truncate race too, and it seemed stupid
to duplicate the synchronisation logic rather than just consolidate the two.After this patch, MAP_NONBLOCK no longer sets up ptes for pages present in
pagecache. Seems like a fringe functionality anyway.NOPAGE_REFAULT is removed. This should be implemented with ->fault, and no
users have hit mainline yet.[akpm@linux-foundation.org: cleanup]
[randy.dunlap@oracle.com: doc. fixes for readahead]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Nick Piggin
Signed-off-by: Randy Dunlap
Cc: Mark Fasheh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix the race between invalidate_inode_pages and do_no_page.
Andrea Arcangeli identified a subtle race between invalidation of pages from
pagecache with userspace mappings, and do_no_page.The issue is that invalidation has to shoot down all mappings to the page,
before it can be discarded from the pagecache. Between shooting down ptes to
a particular page, and actually dropping the struct page from the pagecache,
do_no_page from any process might fault on that page and establish a new
mapping to the page just before it gets discarded from the pagecache.The most common case where such invalidation is used is in file truncation.
This case was catered for by doing a sort of open-coded seqlock between the
file's i_size, and its truncate_count.Truncation will decrease i_size, then increment truncate_count before
unmapping userspace pages; do_no_page will read truncate_count, then find the
page if it is within i_size, and then check truncate_count under the page
table lock and back out and retry if it had subsequently been changed (ptl
will serialise against unmapping, and ensure a potentially updated
truncate_count is actually visible).Complexity and documentation issues aside, the locking protocol fails in the
case where we would like to invalidate pagecache inside i_size. do_no_page
can come in anytime and filemap_nopage is not aware of the invalidation in
progress (as it is when it is outside i_size). The end result is that
dangling (->mapping == NULL) pages that appear to be from a particular file
may be mapped into userspace with nonsense data. Valid mappings to the same
place will see a different page.Andrea implemented two working fixes, one using a real seqlock, another using
a page->flags bit. He also proposed using the page lock in do_no_page, but
that was initially considered too heavyweight. However, it is not a global or
per-file lock, and the page cacheline is modified in do_no_page to increment
_count and _mapcount anyway, so a further modification should not be a large
performance hit. Scalability is not an issue.This patch implements this latter approach. ->nopage implementations return
with the page locked if it is possible for their underlying file to be
invalidated (in that case, they must set a special vm_flags bit to indicate
so). do_no_page only unlocks the page after setting up the mapping
completely. invalidation is excluded because it holds the page lock during
invalidation of each page (and ensures that the page is not mapped while
holding the lock).This also allows significant simplifications in do_no_page, because we have
the page locked in the right place in the pagecache from the start.Signed-off-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 Jul, 2007
2 commits
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currently the export_operation structure and helpers related to it are in
fs.h. fs.h is already far too large and there are very few places needing the
export bits, so split them off into a separate header.[akpm@linux-foundation.org: fix cifs build]
Signed-off-by: Christoph Hellwig
Signed-off-by: Neil Brown
Cc: Steven French
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It is often known at allocation time whether a page may be migrated or not.
This patch adds a flag called __GFP_MOVABLE and a new mask called
GFP_HIGH_MOVABLE. Allocations using the __GFP_MOVABLE can be either migrated
using the page migration mechanism or reclaimed by syncing with backing
storage and discarding.An API function very similar to alloc_zeroed_user_highpage() is added for
__GFP_MOVABLE allocations called alloc_zeroed_user_highpage_movable(). The
flags used by alloc_zeroed_user_highpage() are not changed because it would
change the semantics of an existing API. After this patch is applied there
are no in-kernel users of alloc_zeroed_user_highpage() so it probably should
be marked deprecated if this patch is merged.Note that this patch includes a minor cleanup to the use of __GFP_ZERO in
shmem.c to keep all flag modifications to inode->mapping in the
shmem_dir_alloc() helper function. This clean-up suggestion is courtesy of
Hugh Dickens.Additional credit goes to Christoph Lameter and Linus Torvalds for shaping the
concept. Credit to Hugh Dickens for catching issues with shmem swap vector
and ramfs allocations.[akpm@linux-foundation.org: build fix]
[hugh@veritas.com: __GFP_ZERO cleanup]
Signed-off-by: Mel Gorman
Cc: Andy Whitcroft
Cc: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Jul, 2007
1 commit
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Remove shmem_file_sendfile and resurrect shmem_readpage, as used by tmpfs
to support loop and sendfile in 2.4 and 2.5. Now tmpfs can support splice,
loop and sendfile in the simplest way, using generic_file_splice_read and
generic_file_splice_write (with the aid of shmem_prepare_write).We could make some efficiency tweaks later, if there's a real need;
but this is stable and works well as is.Signed-off-by: Hugh Dickins
Signed-off-by: Jens Axboe
09 Jun, 2007
1 commit
-
Randy Dunlap reports that a tmpfs, mounted with NUMA mpol= specifying an
offline node, crashes as soon as data is allocated upon it. Now restrict it
to online nodes, where before it restricted to MAX_NUMNODES.Signed-off-by: Hugh Dickins
Cc: Robin Holt
Cc: Christoph Lameter
Cc: Andi Kleen
Tested-and-acked-by: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 May, 2007
1 commit
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SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it.
Signed-off-by: Christoph Lameter
Cc: David Howells
Cc: Jens Axboe
Cc: Steven French
Cc: Michael Halcrow
Cc: OGAWA Hirofumi
Cc: Miklos Szeredi
Cc: Steven Whitehouse
Cc: Roman Zippel
Cc: David Woodhouse
Cc: Dave Kleikamp
Cc: Trond Myklebust
Cc: "J. Bruce Fields"
Cc: Anton Altaparmakov
Cc: Mark Fasheh
Cc: Paul Mackerras
Cc: Christoph Hellwig
Cc: Jan Kara
Cc: David Chinner
Cc: "David S. Miller"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 May, 2007
1 commit
-
I have never seen a use of SLAB_DEBUG_INITIAL. It is only supported by
SLAB.I think its purpose was to have a callback after an object has been freed
to verify that the state is the constructor state again? The callback is
performed before each freeing of an object.I would think that it is much easier to check the object state manually
before the free. That also places the check near the code object
manipulation of the object.Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was
compiled with SLAB debugging on. If there would be code in a constructor
handling SLAB_DEBUG_INITIAL then it would have to be conditional on
SLAB_DEBUG otherwise it would just be dead code. But there is no such code
in the kernel. I think SLUB_DEBUG_INITIAL is too problematic to make real
use of, difficult to understand and there are easier ways to accomplish the
same effect (i.e. add debug code before kfree).There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be
clear in fs inode caches. Remove the pointless checks (they would even be
pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors.This is the last slab flag that SLUB did not support. Remove the check for
unimplemented flags from SLUB.Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Mar, 2007
3 commits
-
shmem_truncate_range has its own truncate_inode_pages_range, to free any pages
racily instantiated while it was in progress: a SHMEM_PAGEIN flag is set when
this might have happened. But holepunching gets no chance to clear that flag
at the start of vmtruncate_range, so it's always set (unless a truncate came
just before), so holepunch almost always does this second
truncate_inode_pages_range.shmem holepunch has unlikely swapfile races hereabouts whatever we do
(without a fuller rework than is fit for this release): I was going to skip
the second truncate in the punch_hole case, but Miklos points out that would
make holepunch correctness more vulnerable to swapoff. So keep the second
truncate, but follow it by an unmap_mapping_range to eliminate the
disconnected pages (freed from pagecache while still mapped in userspace) that
it might have left behind.Signed-off-by: Hugh Dickins
Cc: Miklos Szeredi
Cc: Badari Pulavarty
Cc: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Miklos Szeredi observes that during truncation of shmem page directories,
info->lock is released to improve latency (after lowering i_size and
next_index to exclude races); but this is quite wrong for holepunching, which
receives no such protection from i_size or next_index, and is left vulnerable
to races with shmem_unuse, shmem_getpage and shmem_writepage.Hold info->lock throughout when holepunching? No, any user could prevent
rescheduling for far too long. Instead take info->lock just when needed: in
shmem_free_swp when removing the swap entries, and whenever removing a
directory page from the level above. But so long as we remove before
scanning, we can safely skip taking the lock at the lower levels, except at
misaligned start and end of the hole.Signed-off-by: Hugh Dickins
Cc: Miklos Szeredi
Cc: Badari Pulavarty
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Miklos Szeredi observes BUG_ON(!entry) in shmem_writepage() triggered in rare
circumstances, because shmem_truncate_range() erroneously removes partially
truncated directory pages at the end of the range: later reclaim on pages
pointing to these removed directories triggers the BUG. Indeed, and it can
also cause data loss beyond the hole.Fix this as in the patch proposed by Miklos, but distinguish between "limit"
(how far we need to search: ignore truncation's next_index optimization in the
holepunch case - if there are races it's more consistent to act on the whole
range specified) and "upper_limit" (how far we can free directory pages:
generally we must be careful to keep partially punched pages, but can relax at
end of file - i_size being held stable by i_mutex).Signed-off-by: Hugh Dickins
Cc: Miklos Szeredi
Cc: Badari Pulavarty
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Mar, 2007
1 commit
-
shmem's super_operations were missed from the recent const-ification;
and simple_fill_super()'s, which can share with get_sb_pseudo()'s.Signed-off-by: Hugh Dickins
Acked-by: Josef 'Jeff' Sipek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Mar, 2007
1 commit
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shmem_{nopage,mmap} are no longer used in ipc/shm.c
Signed-off-by: Adrian Bunk
Cc: "Eric W. Biederman"
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Feb, 2007
1 commit
-
Many struct inode_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Feb, 2007
1 commit
-
shmem backed file does not have page writeback, nor it participates in
backing device's dirty or writeback accounting. So using generic
__set_page_dirty_nobuffers() for its .set_page_dirty aops method is a bit
overkill. It unnecessarily prolongs shm unmap latency.For example, on a densely populated large shm segment (sevearl GBs), the
unmapping operation becomes painfully long. Because at unmap, kernel
transfers dirty bit in PTE into page struct and to the radix tree tag. The
operation of tagging the radix tree is particularly expensive because it
has to traverse the tree from the root to the leaf node on every dirty
page. What's bothering is that radix tree tag is used for page write back.
However, shmem is memory backed and there is no page write back for such
file system. And in the end, we spend all that time tagging radix tree and
none of that fancy tagging will be used. So let's simplify it by introduce
a new aops __set_page_dirty_no_writeback and this will speed up shm unmap.Signed-off-by: Ken Chen
Cc: Peter Zijlstra
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Dec, 2006
1 commit
-
Ran into BUG() while doing madvise(REMOVE) testing. If we are punching a
hole into shared memory segment using madvise(REMOVE) and the entire hole
is below the indirect blocks, we hit following assert.BUG_ON(limit
Cc: Hugh Dickins
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Dec, 2006
1 commit
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Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in linux/mm/.
Signed-off-by: Josef "Jeff" Sipek
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Dec, 2006
3 commits
-
- move some file_operations structs into the .rodata section
- move static strings from policy_types[] array into the .rodata section
- fix generic seq_operations usages, so that those structs may be defined
as "const" as well[akpm@osdl.org: couple of fixes]
Signed-off-by: Helge Deller
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
SLAB_KERNEL is an alias of GFP_KERNEL.
Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Oct, 2006
1 commit
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Separate out the concept of "queue congestion" from "backing-dev congestion".
Congestion is a backing-dev concept, not a queue concept.The blk_* congestion functions are retained, as wrappers around the core
backing-dev congestion functions.This proper layering is needed so that NFS can cleanly use the congestion
functions, and so that CONFIG_BLOCK=n actually links.Cc: "Thomas Maier"
Cc: "Jens Axboe"
Cc: Trond Myklebust
Cc: David Howells
Cc: Peter Osterlund
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Oct, 2006
1 commit
-
We need to encode a decode the 'file' part of a handle. We simply use the
inode number and generation number to construct the filehandle.The generation number is the time when the file was created. As inode numbers
cycle through the full 32 bits before being reused, there is no real chance of
the same inum being allocated to different files in the same second so this is
suitably unique. Using time-of-day rather than e.g. jiffies makes it less
likely that the same filehandle can be created after a reboot.In order to be able to decode a filehandle we need to be able to lookup by
inum, which means that the inode needs to be added to the inode hash table
(tmpfs doesn't currently hash inodes as there is never a need to lookup by
inum). To avoid overhead when not exporting, we only hash an inode when it is
first exported. This requires a lock to ensure it isn't hashed twice.This code is separate from the patch posted in June06 from Atal Shargorodsky
which provided the same functionality, but does borrow slightly from it.Locking comment: Most filesystems that hash their inodes do so at the point
where the 'struct inode' is initialised, and that has suitable locking
(I_NEW). Here in shmem, we are hashing the inode later, the first time we
need an NFS file handle for it. We no longer have I_NEW to ensure only one
thread tries to add it to the hash table.Cc: Atal Shargorodsky
Cc: Gilad Ben-Yossef
Signed-off-by: David M. Grimes
Signed-off-by: Neil Brown
Acked-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Oct, 2006
2 commits
-
This is mostly included for parity with dec_nlink(), where we will have some
more hooks. This one should stay pretty darn straightforward for now.Signed-off-by: Dave Hansen
Acked-by: Christoph Hellwig
Cc: Al Viro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When a filesystem decrements i_nlink to zero, it means that a write must be
performed in order to drop the inode from the filesystem.We're shortly going to have keep filesystems from being remounted r/o between
the time that this i_nlink decrement and that write occurs.So, add a little helper function to do the decrements. We'll tie into it in a
bit to note when i_nlink hits zero.Signed-off-by: Dave Hansen
Acked-by: Christoph Hellwig
Cc: Al Viro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds