Commit Graph

1201 Commits

Author SHA1 Message Date
Tao Ma
abf1b3cb5b ocfs2: Set ac_last_group properly with discontig group.
ac_last_group is used to record the last block group we
used during allocation. But the initialization process
only calls ocfs2_which_suballoc_group and fails to
use suballoc_loc properly. So let us do it.
Another function ocfs2_test_suballoc_bit also needs fix.

I have searched all the callers of ocfs2_which_suballoc_group,
and all the callers notices suballoc_loc now.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-04-27 08:30:36 +08:00
Tao Ma
74380c479a ocfs2: Free block to the right block group.
In case the block we are going to free is allocated from
a discontiguous block group, we have to use suballoc_loc
to be the right group.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-03-22 14:20:18 +08:00
Tao Ma
af2bf0d860 ocfs2: Add ocfs2_gd_is_discontig.
Add ocfs2_gd_is_discontig so that we can test whether
a group descriptor is discontiguous or not.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-05-17 15:14:17 +08:00
Tao Ma
8571882c21 ocfs2: ocfs2_group_bitmap_size has to handle old volume.
ocfs2_group_bitmap_size has to handle the case when the
volume don't have discontiguous block group support. So
pass the feature_incompat in and check it.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-04-13 14:38:06 +08:00
Tao Ma
4711954eaa ocfs2: Some tiny bug fixes for discontiguous block allocation.
The fixes include:
1. some endian problems.
2. we should use bit/bpc in ocfs2_block_group_grow_discontig to
   allocate clusters.
3. set num_clusters properly in __ocfs2_claim_clusters.
4. change name from ocfs2_supports_discontig_bh to
   ocfs2_supports_discontig_bg.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-04-22 14:09:15 +08:00
Joel Becker
95ec0adf0b ocfs2: Don't relink cluster groups when allocating discontig block groups
We don't have enough credits, and the filesystem is in a full state
anyway.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-26 10:10:08 +08:00
Joel Becker
8b06bc592e ocfs2: Grow discontig block groups in one transaction.
Rather than extending the transaction every time we add an extent to a
discontiguous block group, we grab enough credits to fill the extent
list up front.  This means we can free the bits in the same transaction
if we end up not getting enough space.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-26 10:09:29 +08:00
Joel Becker
2b6cb576aa ocfs2: Set suballoc_loc on allocated metadata.
Get the suballoc_loc from ocfs2_claim_new_inode() or
ocfs2_claim_metadata().  Store it on the appropriate field of the block
we just allocated.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-26 10:09:15 +08:00
Joel Becker
ba2066351b ocfs2: Return allocated metadata blknos on the ocfs2_suballoc_result.
Rather than calculating the resulting block number, return it on the
ocfs2_suballoc_result structure.  This way we can calculate block
numbers for discontiguous block groups.

Cluster groups keep doing it the old way.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-26 10:08:59 +08:00
Joel Becker
1ed9b777f7 ocfs2: ocfs2_claim_*() don't need an ocfs2_super argument.
They all take an ocfs2_alloc_context, which has the allocation inode.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-05-06 13:59:06 +08:00
Joel Becker
13e434cf0c ocfs2: Trim suballocations if they cross discontiguous regions
A discontiguous block group can find a range of free bits that straddle
more than one region of its space.  Callers can't handle that, so we
trim the returned bits until they fit within one region.

Only cluster allocations ask for min_bits>1.  Discontiguous block groups
are only for block allocations.  So min_bits doesn't matter here.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-26 10:08:27 +08:00
Joel Becker
aa8f8e93c8 ocfs2: ocfs2_claim_suballoc_bits() doesn't need an osb argument.
It's contained on ac->ac_inode->i_sb anyway.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-26 10:08:07 +08:00
Joel Becker
9cbc01231e ocfs2: Add suballoc_loc to metadata blocks.
We need a suballoc_loc field on any suballocated block.  Define them.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-26 10:07:42 +08:00
Joel Becker
7d1fe093bf ocfs2: Pass suballocation results back via a structure.
We're going to be adding more info to a suballocator allocation.  Rather
than growing every function in the chain, let's pass a result structure
around.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-04-13 14:30:19 +08:00
Joel Becker
798db35f46 ocfs2: Allocate discontiguous block groups.
If we cannot get a contiguous region for a block group, allocate a
discontiguous one when the filesystem supports it.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-04-13 14:26:32 +08:00
Joel Becker
4cbe4249d6 ocfs2: Define data structures for discontiguous block groups.
Defines the OCFS2_FEATURE_INCOMPAT_DISCONTIG_BG feature bit and modifies
struct ocfs2_group_desc for the feature.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-04-13 14:26:12 +08:00
Sunil Mushran
0467ae954d ocfs2/dlm: Increase o2dlm lockres hash size
Lockres hash size of 16KB is far too small for large filesystems (where we
have hundreds of thousands of lock resources stored in the table).
This patch increases it to 128KB.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:20:01 -07:00
Tao Ma
c901fb0073 ocfs2: Make ocfs2_extend_trans() really extend.
In ocfs2, we use ocfs2_extend_trans() to extend a journal handle's
blocks. But if jbd2_journal_extend() fails, it will only restart
with the the new number of blocks.  This tends to be awkward since
in most cases we want additional reserved blocks. It makes our code
harder to mantain since the caller can't be sure all the original
blocks will not be accessed and dirtied again.  There are 15 callers
of ocfs2_extend_trans() in fs/ocfs2, and 12 of them have to add
h_buffer_credits before they call ocfs2_extend_trans().  This makes
ocfs2_extend_trans() really extend atop the original block count.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:09 -07:00
Tao Ma
3e4218df31 ocfs2/trivial: Code cleanup for allocation reservation.
Two tiny cleanup for allocation reservation.
1. Remove some extra codes in ocfs2_local_alloc_find_clear_bits.
2. Remove an unuseful variables in ocfs2_find_resv_lhs.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:09 -07:00
Tao Ma
b065556a7d ocfs2: make ocfs2_adjust_resv_from_alloc simple.
When we allocate some bits from the reservation, we always
allocate from the r_start(see ocfs2_resmap_resv_bits).
So there should be no reason to check between r_start
and start. And I don't think we will change this behaviour
later by allocating from some bits after r_start.  Why not make
ocfs2_adjust_resv_from_alloc simple for now?

The only chance we have to adjust the reservation is when we haven't
reached the end. With this patch, the function is more readable.

Note:
btw, this patch also fixes an original bug in the function
which I haven't found before.
	if (end < ocfs2_resv_end(resv))
		rhs = end - ocfs2_resv_end(resv);
This code is of course buggy. ;)

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:09 -07:00
Sunil Mushran
4b37fcb7d4 ocfs2: Make nointr a default mount option
OCFS2 has never really supported intr. This patch acknowledges this reality
and makes nointr the default mount option. In a later patch, we intend to
support intr.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:08 -07:00
Sunil Mushran
5c80d4c9e5 ocfs2/dlm: Make o2dlm domain join/leave messages KERN_NOTICE
o2dlm join and leave messages are more than informational as they are
required for debugging locking issues. This patch changes them from
KERN_INFO to KERN_NOTICE.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:08 -07:00
Srinivas Eeda
23fd9abdc8 o2net: log socket state changes
This patch logs socket state changes that lead to socket shutdown.

Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:08 -07:00
Wengang Wang
a5196ec5ef ocfs2: print node # when tcp fails
Print the node number of a peer node if sending it a message failed.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:08 -07:00
Mark Fasheh
83f92318fa ocfs2: Add dir_resv_level mount option
The default behavior for directory reservations stays the same, but we add a
mount option so people can tweak the size of directory reservations
according to their workloads.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:07 -07:00
Mark Fasheh
b07f8f24df ocfs2: change default reservation window sizes
The default reservation size of 4 (32-bit windows) is a bit too ambitious.
Scale it back to 16 bits (resv_level=2). I have been testing various sizes
on a 4-node cluster which runs a mixed workload that is heavily threaded.
With a 256MB local alloc, I get *roughly* the following levels of average file
fragmentation:

resv_level=0	70%
resv_level=1	21%
resv_level=2	23%
resv_level=3	24%
resv_level=4	60%
resv_level=5	did not test
resv_level=6	60%

resv_level=2 seemed like a good compromise between not letting windows be
too small, but not so big that heavier workloads will immediately suffer
without tuning.

This patch also change the behavior of directory reservations - they now
track file reservations.  The previous compromise of giving directory
windows only 8 bits wound up fragmenting more at some window sizes because
file allocations had smaller unused windows to poach from.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:07 -07:00
Mark Fasheh
6b82021b9e ocfs2: increase the default size of local alloc windows
I have observed that the current size of 8M gives us pretty poor
fragmentation on multi-threaded workloads which do lots of writes.

Generally, I can increase the size of local alloc windows and observe a
marked decrease in fragmentation, even up and beyond window sizes of 512
megabytes. This makes sense for a couple reasons - larger local alloc means
more room for reservation windows. On multi-node workloads the larger local
alloc helps as well because we don't have to do window slides as often.

Also, I removed the OCFS2_DEFAULT_LOCAL_ALLOC_SIZE constant as it is no
longer used and the comment above it was out of date.

To test fragmentation, I used a workload which launched 4 threads that did
4k writes into a series of about 140 alternating files.

With resv_level=2, and a 4k/4k file system I observed the following average
fragmentation for various localalloc= parameters:

localalloc=	avg. fragmentation
	8		48
	32		16
	64		10
	120		7

On larger cluster sizes, the difference is more dramatic.

The new default size top out at 256M, which we'll only get for cluster
sizes of 32K and above.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:07 -07:00
Mark Fasheh
73c8a80003 ocfs2: clean up localalloc mount option size parsing
This patch pulls the local alloc sizing code into localalloc.c and provides
a callout to it from ocfs2_fill_super(). Behavior is essentially unchanged
except that I correctly calculate the maximum local alloc size. The old code
in ocfs2_parse_options() calculated the max size as:

ocfs2_local_alloc_size(sb) * 8

which is correct, in bits. Unfortunately though the option passed in is in
megabytes. Ultimately, this bug made no real difference - the shrink code
would catch a too-large size and bring it down to something reasonable.
Still, it's less than efficient as-is.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:18:06 -07:00
Mark Fasheh
a57c8fd2ad ocfs2: remove ocfs2_local_alloc_in_range()
Inodes are always allocated from the global bitmap now so we don't need this
any more. Also, the existing implementation bounces reservations around
needlessly.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2010-05-05 18:17:31 -07:00
Mark Fasheh
33d5d380d6 ocfs2: allocate btree internal block groups from the global bitmap
Otherwise, the need for a very large contiguous allocation tends to
wreak havoc on many inode allocation reservations on the local alloc, thus
ruining any chances for contiguousness.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2010-05-05 18:17:31 -07:00
Mark Fasheh
e3b4a97dbe ocfs2: use allocation reservations for directory data
Use the reservations system for unindexed dir tree allocations. We don't
bother with the indexed tree as reads from it are mostly random anyway.
Directory reservations are marked seperately, to allow the reservations code
a chance to optimize their window sizes. This patch allocates only 8 bits
for directory windows as they generally are not expected to grow as quickly
as file data. Future improvements to dir window sizing can trivially be
made.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2010-05-05 18:17:30 -07:00
Mark Fasheh
4fe370afaa ocfs2: use allocation reservations during file write
Add a per-inode reservations structure and pass it through to the
reservations code.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2010-05-05 18:17:30 -07:00
Mark Fasheh
d02f00cc05 ocfs2: allocation reservations
This patch improves Ocfs2 allocation policy by allowing an inode to
reserve a portion of the local alloc bitmap for itself. The reserved
portion (allocation window) is advisory in that other allocation
windows might steal it if the local alloc bitmap becomes
full. Otherwise, the reservations are honored and guaranteed to be
free. When the local alloc window is moved to a different portion of
the bitmap, existing reservations are discarded.

Reservation windows are represented internally by a red-black
tree. Within that tree, each node represents the reservation window of
one inode. An LRU of active reservations is also maintained. When new
data is written, we allocate it from the inodes window. When all bits
in a window are exhausted, we allocate a new one as close to the
previous one as possible. Should we not find free space, an existing
reservation is pulled off the LRU and cannibalized.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2010-05-05 18:17:30 -07:00
Joel Becker
ec20cec7a3 ocfs2: Make ocfs2_journal_dirty() void.
jbd[2]_journal_dirty_metadata() only returns 0.  It's been returning 0
since before the kernel moved to git.  There is no point in checking
this error.

ocfs2_journal_dirty() has been faithfully returning the status since the
beginning.  All over ocfs2, we have blocks of code checking this can't
fail status.  In the past few years, we've tried to avoid adding these
checks, because they are pointless.  But anyone who looks at our code
assumes they are needed.

Finally, ocfs2_journal_dirty() is made a void function.  All error
checking is removed from other files.  We'll BUG_ON() the status of
jbd2_journal_dirty_metadata() just in case they change it someday.  They
won't.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-05 18:17:29 -07:00
Mark Fasheh
b4414eea0e ocfs2: Clear undo bits when local alloc is freed
When the local alloc file changes windows, unused bits are freed back to the
global bitmap. By defnition, those bits can not be in use by any file. Also,
the local alloc will never have been able to allocate those bits if they
were part of a previous truncate. Therefore it makes sense that we should
clear unused local alloc bits in the undo buffer so that they can be used
immediatly.

[ Modified to call it ocfs2_release_clusters() -- Joel ]

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-23 18:22:40 -07:00
Tao Ma
b23179681c ocfs2: Init meta_ac properly in ocfs2_create_empty_xattr_block.
You can't store a pointer that you haven't filled in yet and expect it
to work.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-19 14:53:52 -07:00
Tao Ma
dfe4d3d6a6 ocfs2: Fix the update of name_offset when removing xattrs
When replacing a xattr's value, in some case we wipe its name/value
first and then re-add it. The wipe is done by
ocfs2_xa_block_wipe_namevalue() when the xattr is in the inode or
block. We currently adjust name_offset for all the entries which have
(offset < name_offset). This does not adjust the entrie we're replacing.
Since we are replacing the entry, we don't adjust the total entry count.
When we calculate a new namevalue location, we trust the entries
now-wrong offset in ocfs2_xa_get_free_start().  The solution is to
also adjust the name_offset for the replaced entry, allowing
ocfs2_xa_get_free_start() to calculate the new namevalue location
correctly.

The following script can trigger a kernel panic easily.

echo 'y'|mkfs.ocfs2 --fs-features=local,xattr -b 4K $DEVICE
mount -t ocfs2 $DEVICE $MNT_DIR
FILE=$MNT_DIR/$RANDOM
for((i=0;i<76;i++))
do
string_76="a$string_76"
done
string_78="aa$string_76"
string_82="aaaa$string_78"

touch $FILE
setfattr -n 'user.test1234567890' -v $string_76 $FILE
setfattr -n 'user.test1234567890' -v $string_78 $FILE
setfattr -n 'user.test1234567890' -v $string_82 $FILE

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-19 14:53:51 -07:00
Mark Fasheh
b22b63ebaf ocfs2: Always try for maximum bits with new local alloc windows
What we were doing before was to ask for the current window size as the
maximum allocation. This had the effect of limiting the amount of allocation
we could get for the local alloc during times when the window size was
shrunk due to fragmentation. In some cases, that could actually *increase*
fragmentation by artificially limiting the number of bits we can accept. So
while we still want to ask for a minimum number of bits equal to window
size, there is no reason why we should limit the number of bits the local
alloc should accept. Hence always allow the maximum number of local alloc
bits.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-18 13:22:42 -07:00
Mark Fasheh
fcefd25ac8 ocfs2: set i_mode on disk during acl operations
ocfs2_set_acl() and ocfs2_init_acl() were setting i_mode on the in-memory
inode, but never setting it on the disk copy. Thus, acls were some times not
getting propagated between nodes. This patch fixes the issue by adding a
helper function ocfs2_acl_set_mode() which does this the right way.
ocfs2_set_acl() and ocfs2_init_acl() are then updated to call
ocfs2_acl_set_mode().

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-17 12:28:22 -07:00
Tao Ma
6527f8f848 ocfs2: Update i_blocks in reflink operations.
In reflink, we need to upate i_blocks for the target inode.

Reported-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-17 12:28:00 -07:00
Tao Ma
78c37eb0d5 ocfs2: Change bg_chain check for ocfs2_validate_gd_parent.
In ocfs2_validate_gd_parent, we check bg_chain against the
cl_next_free_rec of the dinode. Actually in resize, we have
the chance of bg_chain == cl_next_free_rec. So add some
additional condition check for it.

I also rename paramter "clean_error" to "resize", since the
old one is not clearly enough to indicate that we should only
meet with this case in resize.

btw, the correpsonding bug is
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1230.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-17 12:07:21 -07:00
Sachin Prabhu
ee860b6a65 [PATCH] Skip check for mandatory locks when unlocking
ocfs2_lock() will skip locks on file which has mode set to 02666. This
is a problem in cases where the mode of the file is changed after a
process has obtained a lock on the file.

ocfs2_lock() should skip the check for mandatory locks when unlocking a
file.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-17 12:07:16 -07:00
Linus Torvalds
c32da02342 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (56 commits)
  doc: fix typo in comment explaining rb_tree usage
  Remove fs/ntfs/ChangeLog
  doc: fix console doc typo
  doc: cpuset: Update the cpuset flag file
  Fix of spelling in arch/sparc/kernel/leon_kernel.c no longer needed
  Remove drivers/parport/ChangeLog
  Remove drivers/char/ChangeLog
  doc: typo - Table 1-2 should refer to "status", not "statm"
  tree-wide: fix typos "ass?o[sc]iac?te" -> "associate" in comments
  No need to patch AMD-provided drivers/gpu/drm/radeon/atombios.h
  devres/irq: Fix devm_irq_match comment
  Remove reference to kthread_create_on_cpu
  tree-wide: Assorted spelling fixes
  tree-wide: fix 'lenght' typo in comments and code
  drm/kms: fix spelling in error message
  doc: capitalization and other minor fixes in pnp doc
  devres: typo fix s/dev/devm/
  Remove redundant trailing semicolons from macros
  fix typo "definetly" -> "definitely" in comment
  tree-wide: s/widht/width/g typo in comments
  ...

Fix trivial conflict in Documentation/laptops/00-INDEX
2010-03-12 16:04:50 -08:00
Joe Perches
03affdef4f fs/ocfs2/cluster/tcp.c: remove use of NIPQUAD, use %pI4
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:27 -08:00
Jiri Kosina
318ae2edc3 Merge branch 'for-next' into for-linus
Conflicts:
	Documentation/filesystems/proc.txt
	arch/arm/mach-u300/include/mach/debug-macro.S
	drivers/net/qlge/qlge_ethtool.c
	drivers/net/qlge/qlge_main.c
	drivers/net/typhoon.c
2010-03-08 16:55:37 +01:00
Emese Revfy
52cf25d0ab Driver core: Constify struct sysfs_ops in struct kobj_type
Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:49 -08:00
Akinobu Mita
984b3f5746 bitops: rename for_each_bit() to for_each_set_bit()
Rename for_each_bit to for_each_set_bit in the kernel source tree.  To
permit for_each_clear_bit(), should that ever be added.

The patch includes a macro to map the old for_each_bit() onto the new
for_each_set_bit().  This is a (very) temporary thing to ease the migration.

[akpm@linux-foundation.org: add temporary for_each_bit()]
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:23 -08:00
Linus Torvalds
e213e26ab3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: (33 commits)
  quota: stop using QUOTA_OK / NO_QUOTA
  dquot: cleanup dquot initialize routine
  dquot: move dquot initialization responsibility into the filesystem
  dquot: cleanup dquot drop routine
  dquot: move dquot drop responsibility into the filesystem
  dquot: cleanup dquot transfer routine
  dquot: move dquot transfer responsibility into the filesystem
  dquot: cleanup inode allocation / freeing routines
  dquot: cleanup space allocation / freeing routines
  ext3: add writepage sanity checks
  ext3: Truncate allocated blocks if direct IO write fails to update i_size
  quota: Properly invalidate caches even for filesystems with blocksize < pagesize
  quota: generalize quota transfer interface
  quota: sb_quota state flags cleanup
  jbd: Delay discarding buffers in journal_unmap_buffer
  ext3: quota_write cross block boundary behaviour
  quota: drop permission checks from xfs_fs_set_xstate/xfs_fs_set_xquota
  quota: split out compat_sys_quotactl support from quota.c
  quota: split out netlink notification support from quota.c
  quota: remove invalid optimization from quota_sync_all
  ...

Fixed trivial conflicts in fs/namei.c and fs/ufs/inode.c
2010-03-05 13:20:53 -08:00
Christoph Hellwig
871a293155 dquot: cleanup dquot initialize routine
Get rid of the initialize dquot operation - it is now always called from
the filesystem and if a filesystem really needs it's own (which none
currently does) it can just call into it's own routine directly.

Rename the now static low-level dquot_initialize helper to __dquot_initialize
and vfs_dq_init to dquot_initialize to have a consistent namespace.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2010-03-05 00:20:30 +01:00
Christoph Hellwig
907f4554e2 dquot: move dquot initialization responsibility into the filesystem
Currently various places in the VFS call vfs_dq_init directly.  This means
we tie the quota code into the VFS.  Get rid of that and make the
filesystem responsible for the initialization.   For most metadata operations
this is a straight forward move into the methods, but for truncate and
open it's a bit more complicated.

For truncate we currently only call vfs_dq_init for the sys_truncate case
because open already takes care of it for ftruncate and open(O_TRUNC) - the
new code causes an additional vfs_dq_init for those which is harmless.

For open the initialization is moved from do_filp_open into the open method,
which means it happens slightly earlier now, and only for regular files.
The latter is fine because we don't need to initialize it for operations
on special files, and we already do it as part of the namespace operations
for directories.

Add a dquot_file_open helper that filesystems that support generic quotas
can use to fill in ->open.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2010-03-05 00:20:30 +01:00