18 Aug, 2010
2 commits
-
These flags aren't real I/O types, but tell ll_rw_block to always
lock the buffer instead of giving up on a failed trylock.Instead add a new write_dirty_buffer helper that implements this semantic
and use it from the existing SWRITE* callers. Note that the ll_rw_block
code had a bug where it didn't promote WRITE_SYNC_PLUG properly, which
this patch fixes.In the ufs code clean up the helper that used to call ll_rw_block
to mirror sync_dirty_buffer, which is the function it implements for
compound buffers.Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro -
Instead of abusing a buffer_head flag just add a variant of
sync_dirty_buffer which allows passing the exact type of write
flag required.Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro
11 Aug, 2010
1 commit
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (96 commits)
no need for list_for_each_entry_safe()/resetting with superblock list
Fix sget() race with failing mount
vfs: don't hold s_umount over close_bdev_exclusive() call
sysv: do not mark superblock dirty on remount
sysv: do not mark superblock dirty on mount
btrfs: remove junk sb_dirt change
BFS: clean up the superblock usage
AFFS: wait for sb synchronization when needed
AFFS: clean up dirty flag usage
cifs: truncate fallout
mbcache: fix shrinker function return value
mbcache: Remove unused features
add f_flags to struct statfs(64)
pass a struct path to vfs_statfs
update VFS documentation for method changes.
All filesystems that need invalidate_inode_buffers() are doing that explicitly
convert remaining ->clear_inode() to ->evict_inode()
Make ->drop_inode() just return whether inode needs to be dropped
fs/inode.c:clear_inode() is gone
fs/inode.c:evict() doesn't care about delete vs. non-delete paths now
...Fix up trivial conflicts in fs/nilfs2/super.c
10 Aug, 2010
6 commits
-
The comment suggests that when b_count equals zero it is calling
__wait_no_buffer to trigger some debug, but as there is no debug in
__wait_on_buffer the whole thing is redundant.AFAICT from the git log this has been the case for at least 5 years, so
it seems safe just to remove this.Signed-off-by: Richard Kennedy
Cc: Nick Piggin
Cc: Jens Axboe
Cc: Jeff Mahoney
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Copy and simplify in the only two users remaining.
Signed-off-by: Al Viro
-
Move the call to vmtruncate to get rid of accessive blocks to the callers
in preparation of the new truncate sequence and rename the non-truncating
version to block_write_begin.While we're at it also remove several unused arguments to block_write_begin.
Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro -
Split up the block_write_begin implementation - __block_write_begin is a new
trivial wrapper for block_prepare_write that always takes an already
allocated page and can be either called from block_write_begin or filesystem
code that already has a page allocated. Remove the handling of already
allocated pages from block_write_begin after switching all callers that
do it to __block_write_begin.Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro -
Move the call to vmtruncate to get rid of accessive blocks to the callers
in preparation of the new truncate sequence and rename the non-truncating
version to cont_write_begin.Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro -
Move the call to vmtruncate to get rid of accessive blocks to the only
remaining caller and rename the non-truncating version to nobh_write_begin.Get rid of the superflous file argument to it while we're at it.
Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro
28 May, 2010
2 commits
-
Introduce a new truncate calling sequence into fs/mm subsystems. Rather than
setattr > vmtruncate > truncate, have filesystems call their truncate sequence
from ->setattr if filesystem specific operations are required. vmtruncate is
deprecated, and truncate_pagecache and inode_newsize_ok helpers introduced
previously should be used.simple_setattr is introduced for simple in-ram filesystems to implement
the new truncate sequence. Eventually all filesystems should be converted
to implement a setattr, and the default code in notify_change should go
away.simple_setsize is also introduced to perform just the ATTR_SIZE portion
of simple_setattr (ie. changing i_size and trimming pagecache).To implement the new truncate sequence:
- filesystem specific manipulations (eg freeing blocks) must be done in
the setattr method rather than ->truncate.
- vmtruncate can not be used by core code to trim blocks past i_size in
the event of write failure after allocation, so this must be performed
in the fs code.
- convert usage of helpers block_write_begin, nobh_write_begin,
cont_write_begin, and *blockdev_direct_IO* to use _newtrunc postfixed
variants. These avoid calling vmtruncate to trim blocks (see previous).
- inode_setattr should not be used. generic_setattr is a new function
to be used to copy simple attributes into the generic inode.
- make use of the better opportunity to handle errors with the new sequence.Big problem with the previous calling sequence: the filesystem is not called
until i_size has already changed. This means it is not allowed to fail the
call, and also it does not know what the previous i_size was. Also, generic
code calling vmtruncate to truncate allocated blocks in case of error had
no good way to return a meaningful error (or, for example, atomically handle
block deallocation).Cc: Christoph Hellwig
Acked-by: Jan Kara
Signed-off-by: Nick Piggin
Signed-off-by: Al Viro -
Signed-off-by: Christoph Hellwig
Signed-off-by: Al Viro
16 Apr, 2009
1 commit
-
block_write_full_page doesn't allow the caller to control what happens
when the IO is over. This adds a new call named block_write_full_page_endio
so the buffer head end_io handler can be provided by the caller.This will be used by the ext3 data=guarded mode to do i_size updates in
a workqueue based end_io handler. end_buffer_async_write is also
exported so it can be called to do the dirty work of managing page
writeback for the higher level end_io handler.Signed-off-by: Chris Mason
Acked-by: Theodore Tso
Acked-by: Jan Kara
Signed-off-by: Linus Torvalds
03 Apr, 2009
1 commit
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
Remove two unneeded exports and make two symbols static in fs/mpage.c
Cleanup after commit 585d3bc06f4ca57f975a5a1f698f65a45ea66225
Trim includes of fdtable.h
Don't crap into descriptor table in binfmt_som
Trim includes in binfmt_elf
Don't mess with descriptor table in load_elf_binary()
Get rid of indirect include of fs_struct.h
New helper - current_umask()
check_unsafe_exec() doesn't care about signal handlers sharing
New locking/refcounting for fs_struct
Take fs_struct handling to new file (fs/fs_struct.c)
Get rid of bumping fs_struct refcount in pivot_root(2)
Kill unsharing fs_struct in __set_personality()
01 Apr, 2009
2 commits
-
Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags. There should be no functional change.This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg. virtual_address to the
driver, which might be important in some special cases).This is required for a subsequent fix. And will also make it easier to
merge page_mkwrite() with fault() in future.Signed-off-by: Nick Piggin
Cc: Chris Mason
Cc: Trond Myklebust
Cc: Miklos Szeredi
Cc: Steven Whitehouse
Cc: Mark Fasheh
Cc: Joel Becker
Cc: Artem Bityutskiy
Cc: Felix Blyakher
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
fsync_bdev() export and a bunch of stubs for !CONFIG_BLOCK case had
been left behindSigned-off-by: Al Viro
28 Mar, 2009
1 commit
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Move some block device related code out from buffer.c and put it in
block_dev.c. I'm trying to move non-buffer_head code out of buffer.cSigned-off-by: Al Viro
10 Jan, 2009
1 commit
-
The ioctls for the generic freeze feature are below.
o Freeze the filesystem
int ioctl(int fd, int FIFREEZE, arg)
fd: The file descriptor of the mountpoint
FIFREEZE: request code for the freeze
arg: Ignored
Return value: 0 if the operation succeeds. Otherwise, -1o Unfreeze the filesystem
int ioctl(int fd, int FITHAW, arg)
fd: The file descriptor of the mountpoint
FITHAW: request code for unfreeze
arg: Ignored
Return value: 0 if the operation succeeds. Otherwise, -1
Error number: If the filesystem has already been unfrozen,
errno is set to EINVAL.[akpm@linux-foundation.org: fix CONFIG_BLOCK=n]
Signed-off-by: Takashi Sato
Signed-off-by: Masayuki Hamaguchi
Cc:
Cc:
Cc: Christoph Hellwig
Cc: Dave Kleikamp
Cc: Dave Chinner
Cc: Alasdair G Kergon
Cc: Al Viro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Dec, 2008
1 commit
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Allow the scsi request REQ_QUIET flag to be propagated to the buffer
file system layer. The basic ideas is to pass the flag from the scsi
request to the bio (block IO) and then to the buffer layer. The buffer
layer can then suppress needless printks.This patch declutters the kernel log by removed the 40-50 (per lun)
buffer io error messages seen during a boot in my multipath setup . It
is a good chance any real errors will be missed in the "noise" it the
logs without this patch.During boot I see blocks of messages like
"
__ratelimit: 211 callbacks suppressed
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242847
Buffer I/O error on device sdm, logical block 1
Buffer I/O error on device sdm, logical block 5242878
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242879
Buffer I/O error on device sdm, logical block 5242872
"
in my logs.My disk environment is multipath fiber channel using the SCSI_DH_RDAC
code and multipathd. This topology includes an "active" and "ghost"
path for each lun. IO's to the "ghost" path will never complete and the
SCSI layer, via the scsi device handler rdac code, quick returns the IOs
to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi
layer messages.I am wanting to extend the QUIET behavior to include the buffer file
system layer to deal with these errors as well. I have been running this
patch for a while now on several boxes without issue. A few runs of
bonnie++ show no noticeable difference in performance in my setup.Thanks for John Stultz for the quiet_error finalization.
Submitted-by: Keith Mannthey
Signed-off-by: Jens Axboe
20 Oct, 2008
1 commit
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trylock_buffer and unlock_buffer open and close a critical section.
Hence, we can use the lock bitops to get the desired memory ordering.Signed-off-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Aug, 2008
1 commit
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Like the page lock change, this also requires name change, so convert the
raw test_and_set bitop to a trylock.Signed-off-by: Nick Piggin
Signed-off-by: Linus Torvalds
29 Jul, 2008
1 commit
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When we read some part of a file through pagecache, if there is a
pagecache of corresponding index but this page is not uptodate, read IO
is issued and this page will be uptodate.I think this is good for pagesize == blocksize environment but there is
room for improvement on pagesize != blocksize environment. Because in
this case a page can have multiple buffers and even if a page is not
uptodate, some buffers can be uptodate.So I suggest that when all buffers which correspond to a part of a file
that we want to read are uptodate, use this pagecache and copy data from
this pagecache to user buffer even if a page is not uptodate. This can
reduce read IO and improve system throughput.I wrote a benchmark program and got result number with this program.
This benchmark do:
1: mount and open a test file.
2: create a 512MB file.
3: close a file and umount.
4: mount and again open a test file.
5: pwrite randomly 300000 times on a test file. offset is aligned
by IO size(1024bytes).6: measure time of preading randomly 100000 times on a test file.
The result was:
2.6.26
330 sec2.6.26-patched
226 secArch:i386
Filesystem:ext3
Blocksize:1024 bytes
Memory: 1GBOn ext3/4, a file is written through buffer/block. So random read/write
mixed workloads or random read after random write workloads are optimized
with this patch under pagesize != blocksize environment. This test result
showed this.The benchmark program is as follows:
#include
#include
#include
#include
#include
#include
#include
#include
#include#define LEN 1024
#define LOOP 1024*512 /* 512MB */main(void)
{
unsigned long i, offset, filesize;
int fd;
char buf[LEN];
time_t t1, t2;if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
perror("cannot mount\n");
exit(1);
}
memset(buf, 0, LEN);
fd = open("/root/test1/testfile", O_CREAT|O_RDWR|O_TRUNC);
if (fd < 0) {
perror("cannot open file\n");
exit(1);
}
for (i = 0; i < LOOP; i++)
write(fd, buf, LEN);
close(fd);
if (umount("/root/test1/") < 0) {
perror("cannot umount\n");
exit(1);
}
if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
perror("cannot mount\n");
exit(1);
}
fd = open("/root/test1/testfile", O_RDWR);
if (fd < 0) {
perror("cannot open file\n");
exit(1);
}filesize = LEN * LOOP;
for (i = 0; i < 300000; i++){
offset = (random() % filesize) & (~(LEN - 1));
pwrite(fd, buf, LEN, offset);
}
printf("start test\n");
time(&t1);
for (i = 0; i < 100000; i++){
offset = (random() % filesize) & (~(LEN - 1));
pread(fd, buf, LEN, offset);
}
time(&t2);
printf("%ld sec\n", t2-t1);
close(fd);
if (umount("/root/test1/") < 0) {
perror("cannot umount\n");
exit(1);
}
}Signed-off-by: Hisashi Hifumi
Cc: Nick Piggin
Cc: Christoph Hellwig
Cc: Jan Kara
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Apr, 2008
1 commit
-
Remove the obsolete and no longer used generic_commit_write().
Signed-off-by: Adrian Bunk
Cc: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Feb, 2008
1 commit
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FASTCALL() is always expanded to empty, remove it.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Harvey Harrison
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Jan, 2008
1 commit
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Add buffer head related helper function bh_uptodate_or_lock and
bh_submit_read which can be used by file systemSigned-off-by: Aneesh Kumar K.V
17 Oct, 2007
4 commits
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Implement nobh in new aops. This is a bit tricky. FWIW, nobh_truncate is
now implemented in a way that does not create blocks in sparse regions,
which is a silly thing for it to have been doing (isn't it?)ext2 survives fsx and fsstress. jfs is converted as well... ext3
should be easy to do (but not done yet).[akpm@linux-foundation.org: coding-style fixes]
Cc: Badari Pulavarty
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Rework the generic block "cont" routines to handle the new aops. Supporting
cont_prepare_write would take quite a lot of code to support, so remove it
instead (and we later convert all filesystems to use it).write_begin gets passed AOP_FLAG_CONT_EXPAND when called from
generic_cont_expand, so filesystems can avoid the old hacks they used.Signed-off-by: Nick Piggin
Cc: OGAWA Hirofumi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
These are intended to replace prepare_write and commit_write with more
flexible alternatives that are also able to avoid the buffered write
deadlock problems efficiently (which prepare_write is unable to do).[mark.fasheh@oracle.com: API design contributions, code review and fixes]
[akpm@linux-foundation.org: various fixes]
[dmonakhov@sw.ru: new aop block_write_begin fix]
Signed-off-by: Nick Piggin
Signed-off-by: Mark Fasheh
Signed-off-by: Dmitriy Monakhov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Jul, 2007
1 commit
-
Many filesystems need a ->page-mkwrite callout to correctly
set up pages that have been written to by mmap. This is especially
important when mmap is writing into holes as it allows filesystems
to correctly account for and allocate space before the mmap
write is allowed to proceed.Protection against truncate races is provided by locking the page
and checking to see whether the page mapping is correct and whether
it is beyond EOF so we don't end up allowing allocations beyond
the current EOF or changing EOF as a result of a mmap write.SGI-PV: 940392
SGI-Modid: 2.6.x-xfs-melb:linux:29146aSigned-off-by: David Chinner
Signed-off-by: Christoph Hellwig
Signed-off-by: Tim Shimmin
08 May, 2007
2 commits
-
Remove duplicate work in kill_bdev().
It currently invalidates and then truncates the bdev's mapping.
invalidate_mapping_pages() will opportunistically remove pages from the
mapping. And truncate_inode_pages() will forcefully remove all pages.The only thing truncate doesn't do is flush the bh lrus. So do that
explicitly. This avoids (very unlikely) but possible invalid lookup
results if the same bdev is quickly re-issued.It also will prevent extreme kernel latencies which are observed when
blockdevs which have a large amount of pagecache are unmounted, by avoiding
invalidate_mapping_pages() on that path. invalidate_mapping_pages() has no
cond_resched (it can be called under spinlock), whereas truncate_inode_pages()
has one.[akpm@linux-foundation.org: restore nrpages==0 optimisation]
Signed-off-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove the destroy_dirty_buffers argument from invalidate_bdev(), it hasn't
been used in 6 years (so akpm says).find * -name \*.[ch] | xargs grep -l invalidate_bdev |
while read file; do
quilt add $file;
sed -ie 's/invalidate_bdev(\([^,]*\),[^)]*)/invalidate_bdev(\1)/g' $file;
doneSigned-off-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Feb, 2007
2 commits
-
While compiling my code with -Wconversion using gcc-trunk, I always get a
bunch of warrning from headers, here is fix for them:__getblk is alawys called with unsigned argument,
but it takes signed, the same story with __bread,__breadahead and so on.Signed-off-by: Tomasz Kvarsin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently, XFS uses BH_PrivateStart for flagging unwritten extent state in a
bufferhead. Recently, I found the long standing mmap/unwritten extent
conversion bug, and it was to do with partial page invalidation not clearing
the unwritten flag from bufferheads attached to the page but beyond EOF. See
here for a full explaination:http://oss.sgi.com/archives/xfs/2006-12/msg00196.html
The solution I have checked into the XFS dev tree involves duplicating code
from block_invalidatepage to clear the unwritten flag from the bufferhead(s),
and then calling block_invalidatepage() to do the rest.Christoph suggested that this would be better solved by pushing the unwritten
flag into the common buffer head flags and just adding the call to
discard_buffer():http://oss.sgi.com/archives/xfs/2006-12/msg00239.html
The following patch makes BH_Unwritten a first class citizen.
Signed-off-by: Dave Chinner
Acked-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Oct, 2006
1 commit
-
When IO error happens on metadata buffer, buffer is freed from memory and
later fsync() is called, filesystems like ext2 fail to report EIO. Wesolve the problem by introducing a pointer to associated address space into
the buffer_head. When a buffer is removed from a list of metadata buffers
associated with an address space, IO error is transferred from the buffer to
the address space, so that fsync can later report it.Signed-off-by: Jan Kara
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Oct, 2006
2 commits
-
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.Signed-Off-By: David Howells
Signed-off-by: Jens Axboe -
Move some functions out of the buffering code that aren't strictly buffering
specific. This is a precursor to being able to disable the block layer.(*) Moved some stuff out of fs/buffer.c:
(*) The file sync and general sync stuff moved to fs/sync.c.
(*) The superblock sync stuff moved to fs/super.c.
(*) do_invalidatepage() moved to mm/truncate.c.
(*) try_to_release_page() moved to mm/filemap.c.
(*) Moved some related declarations between header files:
(*) declarations for do_invalidatepage() and try_to_release_page() moved
to linux/mm.h.(*) __set_page_dirty_buffers() moved to linux/buffer_head.h.
Signed-Off-By: David Howells
Signed-off-by: Jens Axboe
28 Jun, 2006
1 commit
-
- add a proper prototype for the following global function:
- buffer_init()- make the following needlessly global function static:
- end_buffer_async_write()Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Mar, 2006
3 commits
-
Pass amount of disk needs to be mapped to get_block(). This way one can
modify the fs ->get_block() functions to map multiple blocks at the same time.[akpm@osdl.org: performance tweak]
[akpm@osdl.org: remove unneeded assignments]
Signed-off-by: Badari Pulavarty
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Increase the size of the buffer_head b_size field (only) for 64 bit platforms.
Update some old and moldy comments in and around the structure as well.The b_size increase allows us to perform larger mappings and allocations for
large I/O requests from userspace, which tie in with other changes allowing
the get_block_t() interface to map multiple blocks at once.Signed-off-by: Nathan Scott
Signed-off-by: Badari Pulavarty
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The return value of this function is never used, so let's be honest and
declare it as void.Some places where invalidatepage returned 0, I have inserted comments
suggesting a BUG_ON.[akpm@osdl.org: JBD BUG fix]
[akpm@osdl.org: rework for git-nfs]
[akpm@osdl.org: don't go BUG in block_invalidate_page()]
Signed-off-by: Neil Brown
Acked-by: Dave Kleikamp
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
