Andrew Vasquez is reporting as-iosched oopses and a 65% throughput
slowdown due to the recent special-casing of direct-io against
blockdevs. We don't know why either of these things are occurring.
The patch minimally reverts us back to the 2.6.19 code for a 2.6.20
release.
Cc: Andrew Vasquez <andrew.vasquez@qlogic.com>
Cc: Ken Chen <kenchen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
An AIO bug was reported that sleeping function is being called in softirq
context:
BUG: warning at kernel/mutex.c:132/__mutex_lock_common()
Call Trace:
[<a000000100577b00>] __mutex_lock_slowpath+0x640/0x6c0
[<a000000100577ba0>] mutex_lock+0x20/0x40
[<a0000001000a25b0>] flush_workqueue+0xb0/0x1a0
[<a00000010018c0c0>] __put_ioctx+0xc0/0x240
[<a00000010018d470>] aio_complete+0x2f0/0x420
[<a00000010019cc80>] finished_one_bio+0x200/0x2a0
[<a00000010019d1c0>] dio_bio_complete+0x1c0/0x200
[<a00000010019d260>] dio_bio_end_aio+0x60/0x80
[<a00000010014acd0>] bio_endio+0x110/0x1c0
[<a0000001002770e0>] __end_that_request_first+0x180/0xba0
[<a000000100277b90>] end_that_request_chunk+0x30/0x60
[<a0000002073c0c70>] scsi_end_request+0x50/0x300 [scsi_mod]
[<a0000002073c1240>] scsi_io_completion+0x200/0x8a0 [scsi_mod]
[<a0000002074729b0>] sd_rw_intr+0x330/0x860 [sd_mod]
[<a0000002073b3ac0>] scsi_finish_command+0x100/0x1c0 [scsi_mod]
[<a0000002073c2910>] scsi_softirq_done+0x230/0x300 [scsi_mod]
[<a000000100277d20>] blk_done_softirq+0x160/0x1c0
[<a000000100083e00>] __do_softirq+0x200/0x240
[<a000000100083eb0>] do_softirq+0x70/0xc0
See report: http://marc.theaimsgroup.com/?l=linux-kernel&m=116599593200888&w=2
flush_workqueue() is not allowed to be called in the softirq context.
However, aio_complete() called from I/O interrupt can potentially call
put_ioctx with last ref count on ioctx and triggers bug. It is simply
incorrect to perform ioctx freeing from aio_complete.
The bug is trigger-able from a race between io_destroy() and aio_complete().
A possible scenario:
cpu0 cpu1
io_destroy aio_complete
wait_for_all_aios { __aio_put_req
... ctx->reqs_active--;
if (!ctx->reqs_active)
return;
}
...
put_ioctx(ioctx)
put_ioctx(ctx);
__put_ioctx
bam! Bug trigger!
The real problem is that the condition check of ctx->reqs_active in
wait_for_all_aios() is incorrect that access to reqs_active is not
being properly protected by spin lock.
This patch adds that protective spin lock, and at the same time removes
all duplicate ref counting for each kiocb as reqs_active is already used
as a ref count for each active ioctx. This also ensures that buggy call
to flush_workqueue() in softirq context is eliminated.
Signed-off-by: "Ken Chen" <kenchen@google.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Suparna Bhattacharya <suparna@in.ibm.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: <stable@kernel.org>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The KM_BIO_SRC_IRQ kmap slot requires local irq protection.
Acked-by: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
But keep it as a dprintk
The message can be generated in a quite normal situation:
If a 'lock' request is interrupted, then the lock client needs to
record that the server has the lock, incase it does.
When we come the unlock, the server might say it doesn't, even
though we think it does (or might) and this generates the message.
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In blocks reallocation function sometimes does not update some of
buffer_head::b_blocknr, which may and cause data damage.
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During ufs_trunc_direct which is subroutine of ufs::truncate, we try the first
of all free parts of block and then whole blocks. But we calculate size of
block's part to free in the wrong way.
This may cause bad update of used blocks and fragments statistic, and you can
got report that you have free 32T on 1Gb partition.
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These series of patches result of UFS1 write support stress testing, like
running fsx-linux, untar and build linux kernel etc
We pass from ufs::get_block_t to levels below: pointer to the current page, to
make possible things like reallocation of blocks on the fly, and we also uses
this pointer for indication, what actually we allocate data block or meta data
block, but currently we make decision about what we allocate on the wrong
level, this may and cause oops if we allocate blocks in some special order.
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The BUG in fuse_ctl_add_dentry() could be triggered if the control
filesystem was unmounted and mounted again while one or more fuse
filesystems were present.
The fix is to reset the dentry counter in fuse_ctl_kill_sb().
Bug reported by Florent Mertens.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Also remove {NFSD,RPC}_PARANOIA as having the defines doesn't really add
anything.
The printks covered by RPC_PARANOIA were triggered by badly formatted
packets and so should be ratelimited.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds missing newlines to dprintk's.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix UML hostfs mknod(): userspace has differernt dev_t size and encoding
than kernel, so extract major/minor and reencode using glibc makedev()
macro.
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Acked-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix commit ecdfc9787f
Not to put too fine a point on it, but in a nutshell...
__set_page_dirty_buffers() | try_to_free_buffers()
---------------------------+---------------------------
| spin_lock(private_lock);
| drop_bufers()
| spin_unlock(private_lock);
spin_lock(private_lock) |
!page_has_buffers() |
spin_unlock(private_lock) |
SetPageDirty() |
| cancel_dirty_page()
oops!
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a bug which was introduced when I synced up ocfs2_fs.h with ocfs2-tools.
We can't do u64/u32 in kernel.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Proposed patch to fix#5 in
http://www.isec.pl/vulnerabilities/isec-0017-binfmt_elf.txt
aka
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-1073
To reproduce, do
* grab poc at the end of advisory.
* add line "eph.p_memsz = 4096;" after "eph.p_filesz = 4096;"
where first "4096" is something equal to or greater than 4096.
* ./poc /usr/bin/sudo && ls -l
Here I get with 2.6.20-rc5:
-rw------- 1 ad ad 102400 2007-01-15 19:17 core
---s--x--x 2 root root 101820 2007-01-15 19:15 /usr/bin/sudo
Check for MAY_READ like binfmt_misc.c does.
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
nfsd defines a type 'encode_dent_fn' which is much like 'filldir_t' except
that the first pointer is 'struct readdir_cd *' rather than 'void *'. It
then casts encode_dent_fn points to 'filldir_t' as needed. This hides any
other type mismatches between the two such as the fact that the 'ino' arg
recently changed from ino_t to u64.
So: get rid of 'encode_dent_fn', get rid of the cast of the function type,
change the first arg of various functions from 'struct readdir_cd *' to
'void *', and live with the fact that we have a little less type checking
on the calling of these functions now. Less internal (to nfsd) checking
offset by more external checking, which is more important.
Thanks to Gabriel Paubert <paubert@iram.es> for discovering this and
providing an initial patch.
Signed-off-by: Gabriel Paubert <paubert@iram.es>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We weren't properly NULL terminating protocol error strings for our debug
printk resulting in garbage being included in the output when debug was
enabled.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Running dbench multithreaded exposed a race condition where fid structures
were removed while in use. This patch adds semaphores to meta-data operations
to protect the fid structure. Some cleanup of error-case handling in the
inode operations is also included.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
9p doesn't handle renames between directories -- however, we were returning
EPERM instead of EXDEV when we detected this case.
Signed-off-by: Eric Van Hensbergren <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a simple logic error in init_v9fs - the return code checks are
reversed. This patch fixes the return code and adds some messages to prevent
module initialization from failing silently.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NFS V3 (and V4) support exclusive create by passing a 'cookie' which can get
stored with the file. If the file exists but has exactly the right cookie
stored, then we assume this is a retransmit and the exclusive create was
successful.
The cookie is 64bits and is traditionally stored in the mtime and atime
fields. This causes a problem with Solaris7 as negative mtime or atime
confuse it. So we moved two bits into the mode word instead.
But inherited ACLs sometimes overwrite the mode word on create, so this is a
problem.
So we give up and just store 62 of the 64 bits and assume that is close
enough.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NFSd assumes that largest number of pages that will be needed for a
request+response is 2+N where N pages is the size of the largest permitted
read/write request. The '2' are 1 for the non-data part of the request, and 1
for the non-data part of the reply.
However, when a read request is not page-aligned, and we choose to use
->sendfile to send it directly from the page cache, we may need N+1 pages to
hold the whole reply. This can overflow and array and cause an Oops.
This patch increases size of the array for holding pages by one and makes sure
that entry is NULL when it is not in use.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Due to silly typos, if the nfs versions are explicitly set, no NFSACL versions
get enabled.
Also improve an error message that would have made this bug a little easier to
find.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes core dumps to include the vDSO vma, which is left out now.
It removes the special-case core writing macros, which were not doing the
right thing for the vDSO vma anyway. Instead, it uses VM_ALWAYSDUMP in the
vma; there is no need for the fixmap page to be installed. It handles the
CONFIG_COMPAT_VDSO case by making elf_core_dump use the fake vma from
get_gate_vma after real vmas in the same way the /proc/PID/maps code does.
This changes core dumps so they no longer include the non-PT_LOAD phdrs from
the vDSO. I made the change to add them in the first place, but in turned out
that nothing ever wanted them there since the advent of NT_AUXV. It's cleaner
to leave them out, and just let the phdrs inside the vDSO image speak for
themselves.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds the VM_ALWAYSDUMP flag for vm_flags in vm_area_struct. This
provides a clean explicit way to have a vma always included in core dumps, as
is needed for vDSO's.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In __writeback_single_inode(), when we find a locked inode and we're not
doing a data-integrity sync, we used to just skip writing entirely,
since we didn't want to wait for the inode to unlock.
However, there's really no reason to skip writing the data pages, which
are likely to be the the bulk of the dirty state anyway (and the main
reason why writeback was started for the non-data-integrity case, of
course!)
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Andrew Morton <akpm@osdl.org>,
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's not pretty, but it appears that ext3 with data=journal will clean
pages without ever actually telling the VM that they are clean. This,
in turn, will result in the VM (and balance_dirty_pages() in particular)
to never realize that the pages got cleaned, and wait forever for an
event that already happened.
Technically, this seems to be a problem with ext3 itself, but it used to
be hidden by 'try_to_free_buffers()' noticing this situation on its own,
and just working around the filesystem problem.
This commit re-instates that hack, in order to avoid a regression for
the 2.6.20 release. This fixes bugzilla 7844:
http://bugzilla.kernel.org/show_bug.cgi?id=7844
Peter Zijlstra points out that we should probably retain the debugging
code that this removes from cancel_dirty_page(), and I agree, but for
the imminent release we might as well just silence the warning too
(since it's not a new bug: anything that triggers that warning has been
around forever).
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prevent the call to invalidate_inode_pages2() from racing with file writes
by taking the inode->i_mutex across the page cache flush and invalidate.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes a confusion reiserfs has for a long time.
On release file operation reiserfs used to try to pack file data stored in
last incomplete page of some files into metadata blocks. After packing the
page got cleared with clear_page_dirty. It did not take into account that
the page may be mmaped into other process's address space. Recent
replacement for clear_page_dirty cancel_dirty_page found the confusion with
sanity check that page has to be not mapped.
The patch fixes the confusion by making reiserfs avoid tail packing if an
inode was ever mmapped. reiserfs_mmap and reiserfs_file_release are
serialized with mutex in reiserfs specific inode. reiserfs_mmap locks the
mutex and sets a bit in reiserfs specific inode flags.
reiserfs_file_release checks the bit having the mutex locked. If bit is
set - tail packing is avoided. This eliminates a possibility that mmapped
page gets cancel_page_dirty-ed.
Signed-off-by: Vladimir Saveliev <vs@namesys.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <mason@suse.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For large size DIO that needs multiple bio, one full page worth of data was
lost at the boundary of bio's maximum sector or segment limits. After a
bio is full and got submitted. The outer while (nbytes) { ... } loop will
allocate a new bio and just march on to index into next page. It just
forgets about the page that bio_add_page() rejected when previous bio is
full. Fix it by put the rejected page back to pvec so we pick it up again
for the next bio.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes RedHat bug 211672
Windows sends one byte (instead of two) of null to terminate final Unicode
string (domain name) in session setup response in some cases - this caused
cifs to misalign some informational strings (making it hard to convert
from UCS16 to UTF8).
Thanks to Shaggy for his help and Akemi Yagi for debugging/testing
Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Get rid of some error prints in the ocfs2_iget() path from
ocfs2_get_dentry(). NFSD can easily cause us to read stale inodes.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
ocfs2 wasn't updating c/mtime on directories during dirent
creation/deletion. Fix ocfs2_unlink(), ocfs2_rename() and
__ocfs2_add_entry() by adding the proper code to update the struct inode and
push the change out to disk.
This helps rename/unlink on nfs exported file systems in particular as those
clients compare directory time values to avoid a full re-reading a directory
which hasn't changed.
ocfs2_rename() loses some superfluous error handling as a result of this
patch.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
We shouldn't print errors returned from vfs_follow_link(). This was causing
spurious errors to show up in the logs.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
- Fix deadlock in fs/ntfs/inode.c::ntfs_put_inode(). Thanks to Sergey
Vlasov for the report and detailed analysis of the deadlock. The fix
involved getting rid of ntfs_put_inode() altogether and hence NTFS no
longer has a ->put_inode super operation.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Revert bd_mount_mutex back to a semaphore so that xfs_freeze -f /mnt/newtest;
xfs_freeze -u /mnt/newtest works safely and doesn't produce lockdep warnings.
(XFS unlocks the semaphore from a different task, by design. The mutex
code warns about this)
Signed-off-by: Dave Chinner <dgc@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
NFS: Fix race in nfs_release_page()
invalidate_inode_pages2() may find the dirty bit has been set on a page
owing to the fact that the page may still be mapped after it was locked.
Only after the call to unmap_mapping_range() are we sure that the page
can no longer be dirtied.
In order to fix this, NFS has hooked the releasepage() method and tries
to write the page out between the call to unmap_mapping_range() and the
call to remove_mapping(). This, however leads to deadlocks in the page
reclaim code, where the page may be locked without holding a reference
to the inode or dentry.
Fix is to add a new address_space_operation, launder_page(), which will
attempt to write out a dirty page without releasing the page lock.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Also, the bare SetPageDirty() can skew all sort of accounting leading to
other nasties.
[akpm@osdl.org: cleanup]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Revert previous attempts at messing with the linux banner string and
simply use a separate format string for proc.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Acked-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: Andrey Borzenkov <arvidjaar@mail.ru>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Don't use ref->flash_offset directly in debugging code, use the ref_offset macro instead.
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>
This reverts commit 59287c0913.
Hugh Dickins reports that it causes random failures on x86 with SuSE
10.2, and points out
"Isn't that randomization, anywhere from 0x10000 to ELF_ET_DYN_BASE,
sure to place the ET_DYN from time to time just where the comment
says it's trying to avoid? I assume that somehow results in the error
reported."
(where the comment in question is the existing comment in the source
code about mmap/brk clashes).
Suggested-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Marcus Meissner <meissner@suse.de>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Looks like this is the problem, which point Al Viro some time ago:
ufs's get_block callback allocates 16k of disk at a time, and links that
entire 16k into the file's metadata. But because get_block is called for only
a single buffer_head (a 2k buffer_head in this case?) we are only able to tell
the VFS that this 2k is buffer_new().
So when ufs_getfrag_block() is later called to map some more data in the file,
and when that data resides within the remaining 14k of this fragment,
ufs_getfrag_block() will incorrectly return a !buffer_new() buffer_head.
I don't see _right_ way to do nullification of whole block, if use inode
page cache, some pages may be outside of inode limits (inode size), and
will be lost; if use blockdev page cache it is possible to zero real data,
if later inode page cache will be used.
The simpliest way, as can I see usage of block device page cache, but not only
mark dirty, but also sync it during "nullification". I use my simple tests
collection, which I used for check that create,open,write,read,close works on
ufs, and I see that this patch makes ufs code 18% slower then before.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Andrew Morton