The following patch is a combination of a patch by myself and Peter
Staubach.
Trond: If we allow other processes to dirty pages while a process is doing
a consistency sync to disk, we can end up never making progress.
Peter: Attached is a patch which addresses a continuing problem with
the NFS client generating out of order WRITE requests. While
this is compliant with all of the current protocol
specifications, there are servers in the market which can not
handle out of order WRITE requests very well. Also, this may
lead to sub-optimal block allocations in the underlying file
system on the server. This may cause the read throughputs to
be reduced when reading the file from the server.
Peter: There has been a lot of work recently done to address out of
order issues on a systemic level. However, the NFS client is
still susceptible to the problem. Out of order WRITE
requests can occur when pdflush is in the middle of writing
out pages while the process dirtying the pages calls
generic_file_buffered_write which calls
generic_perform_write which calls
balance_dirty_pages_rate_limited which ends up calling
writeback_inodes which ends up calling back into the NFS
client to writes out dirty pages for the same file that
pdflush happens to be working with.
Signed-off-by: Peter Staubach <staubach@redhat.com>
[modification by Trond to merge the two similar patches]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The main problem is dealing with inode->i_size: we need to set the
inode->i_lock on all attribute updates, and so vmtruncate won't cut it.
Make an NFS-private version of vmtruncate that has the necessary locking
semantics.
The result should be that the following inode attribute updates are
protected by inode->i_lock
nfsi->cache_validity
nfsi->read_cache_jiffies
nfsi->attrtimeo
nfsi->attrtimeo_timestamp
nfsi->change_attr
nfsi->last_updated
nfsi->cache_change_attribute
nfsi->access_cache
nfsi->access_cache_entry_lru
nfsi->access_cache_inode_lru
nfsi->acl_access
nfsi->acl_default
nfsi->nfs_page_tree
nfsi->ncommit
nfsi->npages
nfsi->open_files
nfsi->silly_list
nfsi->acl
nfsi->open_states
inode->i_size
inode->i_atime
inode->i_mtime
inode->i_ctime
inode->i_nlink
inode->i_uid
inode->i_gid
The following is protected by dir->i_mutex
nfsi->cookieverf
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, if an unstable write completes, we cannot redirty the page in
order to reflect a new change in the page data until after we've sent a
COMMIT request.
This patch allows a page rewrite to proceed without the unnecessary COMMIT
step, putting it immediately back onto the dirty page list, undoing the
VM unstable write accounting, and removing the NFS_PAGE_TAG_COMMIT tag from
the NFS radix tree.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Simplify the loop in nfs_update_request by moving into a separate function
the code that attempts to update an existing cached NFS write.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: fix a few dprintk messages that still need to show the RPC task ID
correctly, and be sure we use the preferred %lld or %llu instead of %Ld or
%Lu.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Revert commit 44dd151d "NFS: Don't mark a written page as uptodate until it
is on disk". While it is true that the write may fail, that is always the
case. There is no reason why we should treat data on pages that are not
already marked as PG_uptodate as being special. The only thing we gain is a
noticeable slowdown when re-reading these pages.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If a file is being extended, and we're creating a hole, we might as well
declare the entire page to be up to date.
This patch significantly improves the write performance for sparse files
in the case where lseek(SEEK_END) is used to append several non-contiguous
writes at intervals of < PAGE_SIZE.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The commit 2785259631 (nfs: use GFP_NOFS
preloads for radix-tree insertion) appears to have introduced a bug:
We only want to call radix_tree_preload() once after creating a request.
Calling it every time we loop after we created the request, will cause
preemption count leaks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Nick Piggin <npiggin@suse.de>
When called from nfs_flush_incompatible, the req is not locked, so
req->wb_page might be set to NULL before it is used by PageWriteback.
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It is possible for nfs_wb_page() to sometimes exit with 0 return value, yet
the page is left in a dirty state.
For instance in the case where the server rebooted, and the COMMIT request
failed, then all the previously "clean" pages which were cached by the
server, but were not guaranteed to have been writted out to disk,
have to be redirtied and resent to the server.
The fix is to have nfs_wb_page_priority() check that the page is clean
before it exits...
This fixes a condition that triggers the BUG_ON(PagePrivate(page)) in
nfs_create_request() when we're in the nfs_readpage() path.
Also eliminate a redundant BUG_ON(!PageLocked(page)) while we're at it. It
turns out that clear_page_dirty_for_io() has the exact same test.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Both flush functions have the same error handling routine. Pull
it out as a function.
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ignoring the return value from nfs_pageio_add_request can cause deadlocks.
In read path:
call nfs_pageio_add_request from readpage_async_filler
assume at this point that there are requests already in desc, that
can't be merged with the current request.
so nfs_pageio_doio is fired up to clear out desc.
assume something goes wrong in setting up the io, so desc->pg_error is set.
This causes nfs_pageio_add_request to return 0, *WITHOUT* adding the original
request.
BUT, since return code is ignored, readpage_async_filler assumes it has
been added, and does nothing further, leaving page locked.
do_generic_mapping_read will eventually call lock_page, resulting in deadlock
In write path:
page is marked dirty by generic_perform_write
nfs_writepages is called
call nfs_pageio_add_request from nfs_page_async_flush
assume at this point that there are requests already in desc, that
can't be merged with the current request.
so nfs_pageio_doio is fired up to clear out desc.
assume something goes wrong in setting up the io, so desc->pg_error is set.
This causes nfs_page_async_flush to return 0, *WITHOUT* adding the original
request, yet marking the request as locked (PG_BUSY) and in writeback,
clearing dirty marks.
The next time a write is done to the page, deadlock will result as
nfs_write_end calls nfs_update_request
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Now that we've tightened up the locking rules for RPC queue wakeups, we can
remove the RCU-safe kfree calls...
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We want to ensure that rpc_call_ops that involve mntput() are run on nfsiod
rather than on rpciod, so that they don't deadlock when the resulting
umount calls rpc_shutdown_client(). Hence we specify that read, write and
commit calls must complete on nfsiod.
Ditto for NFSv4 open, lock, locku and close asynchronous calls.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We can't allow rpc callback functions like task->tk_ops->rpc_call_prepare()
and task->tk_ops->rpc_call_done() to call mntput() in any way, since
that will cause a deadlock when the call to rpc_shutdown_client() attempts
to wait on 'task' to complete.
We can avoid the above deadlock by moving calls to mntput to
task->tk_ops->rpc_release() callback, since at that time the task will be
marked as completed, and so rpc_shutdown_client won't attempt to wait on
it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS should use GFP_NOFS mode radix tree preloads rather than GFP_ATOMIC
allocations at radix-tree insertion-time. This is important to reduce the
atomic memory requirement.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the inode is flagged as having an invalid mapping, then we can't rely on
the PageUptodate() flag. Ensure that we don't use the "anti-fragmentation"
write optimisation in nfs_updatepage(), since that will cause NFS to write
out areas of the page that are no longer guaranteed to be up to date.
A potential corruption could occur in the following scenario:
client 1 client 2
=============== ===============
fd=open("f",O_CREAT|O_WRONLY,0644);
write(fd,"fubar\n",6); // cache last page
close(fd);
fd=open("f",O_WRONLY|O_APPEND);
write(fd,"foo\n",4);
close(fd);
fd=open("f",O_WRONLY|O_APPEND);
write(fd,"bar\n",4);
close(fd);
-----
The bug may lead to the file "f" reading 'fubar\n\0\0\0\nbar\n' because
client 2 does not update the cached page after re-opening the file for
write. Instead it keeps it marked as PageUptodate() until someone calls
invaldate_inode_pages2() (typically by calling read()).
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Simplify page cache zeroing of segments of pages through 3 functions
zero_user_segments(page, start1, end1, start2, end2)
Zeros two segments of the page. It takes the position where to
start and end the zeroing which avoids length calculations and
makes code clearer.
zero_user_segment(page, start, end)
Same for a single segment.
zero_user(page, start, length)
Length variant for the case where we know the length.
We remove the zero_user_page macro. Issues:
1. Its a macro. Inline functions are preferable.
2. The KM_USER0 macro is only defined for HIGHMEM.
Having to treat this special case everywhere makes the
code needlessly complex. The parameter for zeroing is always
KM_USER0 except in one single case that we open code.
Avoiding KM_USER0 makes a lot of code not having to be dealing
with the special casing for HIGHMEM anymore. Dealing with
kmap is only necessary for HIGHMEM configurations. In those
configurations we use KM_USER0 like we do for a series of other
functions defined in highmem.h.
Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
function could not be a macro. zero_user_* functions introduced
here can be be inline because that constant is not used when these
functions are called.
Also extract the flushing of the caches to be outside of the kmap.
[akpm@linux-foundation.org: fix nfs and ntfs build]
[akpm@linux-foundation.org: fix ntfs build some more]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc: (22 commits)
Remove commented-out code copied from NFS
NFS: Switch from intr mount option to TASK_KILLABLE
Add wait_for_completion_killable
Add wait_event_killable
Add schedule_timeout_killable
Use mutex_lock_killable in vfs_readdir
Add mutex_lock_killable
Use lock_page_killable
Add lock_page_killable
Add fatal_signal_pending
Add TASK_WAKEKILL
exit: Use task_is_*
signal: Use task_is_*
sched: Use task_contributes_to_load, TASK_ALL and TASK_NORMAL
ptrace: Use task_is_*
power: Use task_is_*
wait: Use TASK_NORMAL
proc/base.c: Use task_is_*
proc/array.c: Use TASK_REPORT
perfmon: Use task_is_*
...
Fixed up conflicts in NFS/sunrpc manually..
Clean up: PAGE_CACHE_SIZE is unsigned, and nfs_pageio_init() takes a size_t.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Move the common code for setting up the nfs_write_data and nfs_read_data
structures into fs/nfs/read.c, fs/nfs/write.c and fs/nfs/direct.c.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We want the default scheduling priority (priority == 0) to remain
RPC_PRIORITY_NORMAL.
Also ensure that the priority wait queue scheduling is per process id
instead of sometimes being per thread, and sometimes being per inode.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
By using the TASK_KILLABLE infrastructure, we can get rid of the 'intr'
mount option. We have to use _killable everywhere instead of _interruptible
as we get rid of rpc_clnt_sigmask/sigunmask.
Signed-off-by: Liam R. Howlett <howlett@gmail.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
nfs_wb_page_priority() can now become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch fixes a regression that was introduced by commit
44dd151d5c
We cannot zero the user page in nfs_mark_uptodate() any more, since
a) We'd be modifying the page without holding the page lock
b) We can race with other updates of the page, most notably
because of the call to nfs_wb_page() in nfs_writepage_setup().
Instead, we do the zeroing in nfs_update_request() if we see that we're
creating a request that might potentially be marked as up to date.
Thanks to Olivier Paquet for reporting the bug and providing a test-case.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
These patches aim to improve balance_dirty_pages() and directly address three
issues:
1) inter device starvation
2) stacked device deadlocks
3) inter process starvation
1 and 2 are a direct result from removing the global dirty limit and using
per device dirty limits. By giving each device its own dirty limit is will
no longer starve another device, and the cyclic dependancy on the dirty limit
is broken.
In order to efficiently distribute the dirty limit across the independant
devices a floating proportion is used, this will allocate a share of the total
limit proportional to the device's recent activity.
3 is done by also scaling the dirty limit proportional to the current task's
recent dirty rate.
This patch:
nfs: remove congestion_end(). It's redundant, clear_bdi_congested() already
wakes the waiters.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The lower level routines in fs/nfs/proc.c, fs/nfs/nfs3proc.c and
fs/nfs/nfs4proc.c should already be dealing with the revalidation issues.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This helps prevent huge queues of background writes from building up
whenever the server runs out of disk or quota space, or if someone changes
the file access modes behind our backs.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Schedule writes using WB_SYNC_NONE first, then come back for a second pass
using WB_SYNC_ALL.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The only user of nfs_sync_mapping_range() is nfs_getattr(), which uses it
to flush out the entire inode without sending a commit. We therefore
replace nfs_sync_mapping_range with a more appropriate helper.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Just call write_cache_pages directly instead of hacking the writeback
control structure in order to find out if we were called from writepages()
or directly from the VM.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The addition of nfs_page_mkwrite means that We should no longer need to
create requests inside nfs_writepage()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ryusuke Konishi says:
The recent truncate_complete_page() clears the dirty flag from a page
before calling a_ops->invalidatepage(),
^^^^^^
static void
truncate_complete_page(struct address_space *mapping, struct page *page)
{
...
cancel_dirty_page(page, PAGE_CACHE_SIZE); <--- Inserted here at
kernel 2.6.20
if (PagePrivate(page))
do_invalidatepage(page, 0); ---> will call
a_ops->invalidatepage()
...
}
and this is disturbing nfs_wb_page_priority() from calling
nfs_writepage_locked() that is expected to handle the pending
request (=nfs_page) associated with the page.
int nfs_wb_page_priority(struct inode *inode, struct page *page, int how)
{
...
if (clear_page_dirty_for_io(page)) {
ret = nfs_writepage_locked(page, &wbc);
if (ret < 0)
goto out;
}
...
}
Since truncate_complete_page() will get rid of the page after
a_ops->invalidatepage() returns, the request (=nfs_page) associated
with the page becomes a garbage in nfs_inode->nfs_page_tree.
------------------------
Fix this by ensuring that nfs_wb_page_priority() recognises that it may
also need to clear out non-dirty pages that have an nfs_page associated
with them.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Slab destructors were no longer supported after Christoph's
c59def9f22 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 <lethal@linux-sh.org>
There is no justification for keeping a special spinlock for the exclusive
use of the NFS writeback code.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The write may fail, so we should not mark the page as uptodate until we are
certain that the data has been accepted and written to disk by the server.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When processes are allowed to attempt to lock a non-contiguous range of nfs
write requests, it is possible for generic_writepages to 'wrap round' the
address space, and call writepage() on a request that is already locked by
the same process.
We avoid the deadlock by checking if the page index is contiguous with the
list of nfs write requests that is already held in our
nfs_pageio_descriptor prior to attempting to lock a new request.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
- fs/nfs/dir.c:610:8: warning: symbol 'nfs_llseek_dir' was not declared.
Should it be static?
- fs/nfs/dir.c:636:5: warning: symbol 'nfs_fsync_dir' was not declared.
Should it be static?
- fs/nfs/write.c:925:19: warning: symbol 'req' shadows an earlier one
- fs/nfs/write.c:61:6: warning: symbol 'nfs_commit_rcu_free' was not
declared. Should it be static?
- fs/nfs/nfs4proc.c:793:5: warning: symbol 'nfs4_recover_expired_lease'
was not declared. Should it be static?
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Use zero_user_page() instead of the newly deprecated memclear_highpage_flush().
Signed-off-by: Nate Diller <nate.diller@gmail.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Change the atomic_t in struct nfs_server to atomic_long_t in anticipation
of machines that can handle 8+TB of (4K) pages under writeback.
However I suspect other things in NFS will start going *bang* by then.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we do write coalescing in a very inefficient manner: one pass in
generic_writepages() in order to lock the pages for writing, then one pass
in nfs_flush_mapping() and/or nfs_sync_mapping_wait() in order to gather
the locked pages for coalescing into RPC requests of size "wsize".
In fact, it turns out there is actually a deadlock possible here since we
only start I/O on the second pass. If the user signals the process while
we're in nfs_sync_mapping_wait(), for instance, then we may exit before
starting I/O on all the requests that have been queued up.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It is redundant, and will interfere with the call to
balance_dirty_pages_ratelimited_nr in generic_file_write().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Redirtying a request that is already marked for commit will screw up the
accounting for NR_UNSTABLE_NFS as well as nfs_i.ncommit.
Ensure that all requests on the commit queue are labelled with the
PG_NEED_COMMIT flag, and avoid moving them onto the dirty list inside
nfs_page_mark_flush().
Also inline nfs_mark_request_dirty() into nfs_page_mark_flush() for
atomicity reasons. Avoid dropping the spinlock until we're done marking the
request in the radix tree and have added it to the ->dirty list.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ensure that we don't release the PG_writeback lock until after the page has
either been redirtied, or queued on the nfs_inode 'commit' list.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Get rid of the inlined #ifdefs.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We must remove the request from whatever list it is currently on before we
can add it to the dirty list.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the writebacks are cancelled via nfs_cancel_dirty_list, or due to the
memory allocation failing in nfs_flush_one/nfs_flush_multi, then we must
ensure that the PG_writeback flag is cleared.
Also ensure that we actually own the PG_writeback flag whenever we
schedule a new writeback by making nfs_set_page_writeback() return the
value of test_set_page_writeback().
The PG_writeback page flag ends up replacing the functionality of the
PG_FLUSHING nfs_page flag, so we rip that out too.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current NFS client congestion logic is severly broken, it marks the
backing device congested during each nfs_writepages() call but doesn't
mirror this in nfs_writepage() which makes for deadlocks. Also it
implements its own waitqueue.
Replace this by a more regular congestion implementation that puts a cap on
the number of active writeback pages and uses the bdi congestion waitqueue.
Also always use an interruptible wait since it makes sense to be able to
SIGKILL the process even for mounts without 'intr'.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ClearPageUptodate() will just cause races here. What we really want to do
is to invalidate the page cache.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The tk_pid field is an unsigned short. The proper print format specifier for
that type is %5u, not %4d.
Also clean up some miscellaneous print formatting nits.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the nfs
client code.
Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Replace all uses of kmem_cache_t with struct kmem_cache.
The patch was generated using the following script:
#!/bin/sh
#
# Replace one string by another in all the kernel sources.
#
set -e
for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
quilt add $file
sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
mv /tmp/$$ $file
quilt refresh
done
The script was run like this
sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
SLAB_NOFS is an alias of GFP_NOFS.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There is now no reason to account for the dirty pages in the NFS code,
since the VM code will now do it for us via __set_page_dirty_nobuffers(),
and set_page_writeback().
We still need to keep the accounting of stable writes, though.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This will ensure that we can call set_page_writeback() from within
nfs_writepage(), which is always called with the page lock set.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We will want to allow nfs_writepage() to distinguish between pages that
have been marked as dirty by the VM, and those that have been marked as
dirty by nfs_updatepage().
In the former case, the entire page will want to be written out, and so any
requests that were pending need to be flushed out first.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Maintaining two parallel ways of doing synchronous writes is rather
pointless. This patch gets rid of the legacy nfs_writepage_sync(), and
replaces it with the faster asynchronous writes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We always ensure that the nfs_open_context holds a reference to the dentry,
so the test in nfs_writepage() for whether or not the inode is referenced
is redundant.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This will allow fast lookup of the nfs_page from the struct page instead of
having to search the radix tree.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Remove use of the Big Kernel Lock around calls to rpc_execute.
Signed-off-by: Frank Filz <ffilz@us.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently nfs_sync_inode_wait() will fail to loop correctly when we call
nfs_sync_inode_wait with the FLUSH_INVALIDATE argument.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Use RCU to ensure that we can safely call rpc_finish_wakeup after we've
called __rpc_do_wake_up_task. If not, there is a theoretical race, in which
the rpc_task finishes executing, and gets freed first.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix two bugs:
- nfs_inode_remove_request will call nfs_clear_request, so we cannot
reference req->wb_page after it. Move the call to dec_zone_page_state so
that it occurs while req->wb_page is still valid.
- Calling nfs_clear_page_writeback is unnecessary since the radix tree
tags will have been cleared by the call to nfs_inode_remove_request.
Replace with a simple call to nfs_unlock_request.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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" <balagi@justmail.de>
Cc: "Jens Axboe" <jens.axboe@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: David Howells <dhowells@redhat.com>
Cc: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove inclusions of linux/mpage.h that are no longer necessary due to the
transfer of generic_writepages().
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Rougly half of callers already do it by not checking return value
* Code in drivers/acpi/osl.c does the following to be sure:
(void)kmem_cache_destroy(cache);
* Those who check it printk something, however, slab_error already printed
the name of failed cache.
* XFS BUGs on failed kmem_cache_destroy which is not the decision
low-level filesystem driver should make. Converted to ignore.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Comments-only change to clarify a detail of the NFS protocol and how it is
implemented in Linux.
Test plan:
None.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The attached patch makes NFS share superblocks between mounts from the same
server and FSID over the same protocol.
It does this by creating each superblock with a false root and returning the
real root dentry in the vfsmount presented by get_sb(). The root dentry set
starts off as an anonymous dentry if we don't already have the dentry for its
inode, otherwise it simply returns the dentry we already have.
We may thus end up with several trees of dentries in the superblock, and if at
some later point one of anonymous tree roots is discovered by normal filesystem
activity to be located in another tree within the superblock, the anonymous
root is named and materialises attached to the second tree at the appropriate
point.
Why do it this way? Why not pass an extra argument to the mount() syscall to
indicate the subpath and then pathwalk from the server root to the desired
directory? You can't guarantee this will work for two reasons:
(1) The root and intervening nodes may not be accessible to the client.
With NFS2 and NFS3, for instance, mountd is called on the server to get
the filehandle for the tip of a path. mountd won't give us handles for
anything we don't have permission to access, and so we can't set up NFS
inodes for such nodes, and so can't easily set up dentries (we'd have to
have ghost inodes or something).
With this patch we don't actually create dentries until we get handles
from the server that we can use to set up their inodes, and we don't
actually bind them into the tree until we know for sure where they go.
(2) Inaccessible symbolic links.
If we're asked to mount two exports from the server, eg:
mount warthog:/warthog/aaa/xxx /mmm
mount warthog:/warthog/bbb/yyy /nnn
We may not be able to access anything nearer the root than xxx and yyy,
but we may find out later that /mmm/www/yyy, say, is actually the same
directory as the one mounted on /nnn. What we might then find out, for
example, is that /warthog/bbb was actually a symbolic link to
/warthog/aaa/xxx/www, but we can't actually determine that by talking to
the server until /warthog is made available by NFS.
This would lead to having constructed an errneous dentry tree which we
can't easily fix. We can end up with a dentry marked as a directory when
it should actually be a symlink, or we could end up with an apparently
hardlinked directory.
With this patch we need not make assumptions about the type of a dentry
for which we can't retrieve information, nor need we assume we know its
place in the grand scheme of things until we actually see that place.
This patch reduces the possibility of aliasing in the inode and page caches for
inodes that may be accessed by more than one NFS export. It also reduces the
number of superblocks required for NFS where there are many NFS exports being
used from a server (home directory server + autofs for example).
This in turn makes it simpler to do local caching of network filesystems, as it
can then be guaranteed that there won't be links from multiple inodes in
separate superblocks to the same cache file.
Obviously, cache aliasing between different levels of NFS protocol could still
be a problem, but at least that gives us another key to use when indexing the
cache.
This patch makes the following changes:
(1) The server record construction/destruction has been abstracted out into
its own set of functions to make things easier to get right. These have
been moved into fs/nfs/client.c.
All the code in fs/nfs/client.c has to do with the management of
connections to servers, and doesn't touch superblocks in any way; the
remaining code in fs/nfs/super.c has to do with VFS superblock management.
(2) The sequence of events undertaken by NFS mount is now reordered:
(a) A volume representation (struct nfs_server) is allocated.
(b) A server representation (struct nfs_client) is acquired. This may be
allocated or shared, and is keyed on server address, port and NFS
version.
(c) If allocated, the client representation is initialised. The state
member variable of nfs_client is used to prevent a race during
initialisation from two mounts.
(d) For NFS4 a simple pathwalk is performed, walking from FH to FH to find
the root filehandle for the mount (fs/nfs/getroot.c). For NFS2/3 we
are given the root FH in advance.
(e) The volume FSID is probed for on the root FH.
(f) The volume representation is initialised from the FSINFO record
retrieved on the root FH.
(g) sget() is called to acquire a superblock. This may be allocated or
shared, keyed on client pointer and FSID.
(h) If allocated, the superblock is initialised.
(i) If the superblock is shared, then the new nfs_server record is
discarded.
(j) The root dentry for this mount is looked up from the root FH.
(k) The root dentry for this mount is assigned to the vfsmount.
(3) nfs_readdir_lookup() creates dentries for each of the entries readdir()
returns; this function now attaches disconnected trees from alternate
roots that happen to be discovered attached to a directory being read (in
the same way nfs_lookup() is made to do for lookup ops).
The new d_materialise_unique() function is now used to do this, thus
permitting the whole thing to be done under one set of locks, and thus
avoiding any race between mount and lookup operations on the same
directory.
(4) The client management code uses a new debug facility: NFSDBG_CLIENT which
is set by echoing 1024 to /proc/net/sunrpc/nfs_debug.
(5) Clone mounts are now called xdev mounts.
(6) Use the dentry passed to the statfs() op as the handle for retrieving fs
statistics rather than the root dentry of the superblock (which is now a
dummy).
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The logic in nfs_direct_read_schedule and nfs_direct_write_schedule can
allow data->npages to be one larger than rpages. This causes a page
pointer to be written beyond the end of the pagevec in nfs_read_data (or
nfs_write_data).
Fix this by making nfs_(read|write)_alloc() calculate the size of the
pagevec array, and initialise data->npages.
Also get rid of the redundant argument to nfs_commit_alloc().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
nfs_writedata_free() and nfs_readdata_free() can now become static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
(cherry picked from 5e1ce40f0c3c8f67591aff17756930d7a18ceb1a commit)
The introduction of the FLUSH_INVALIDATE argument to nfs_sync_inode_wait()
does not clear the nr_unstable page state counter for pages that are being
released.
Also fix a longstanding similar bug when nfs_commit_list() fails.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Conversion of nr_unstable to a per zone counter
We need to do some special modifications to the nfs code since there are
multiple cases of disposition and we need to have a page ref for proper
accounting.
This converts the last critical page state of the VM and therefore we need to
remove several functions that were depending on GET_PAGE_STATE_LAST in order
to make the kernel compile again. We are only left with event type counters
in page state.
[akpm@osdl.org: bugfixes]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This makes nr_dirty a per zone counter. Looping over all processors is
avoided during writeback state determination.
The counter aggregation for nr_dirty had to be undone in the NFS layer since
we summed up the page counts from multiple zones. Someone more familiar with
NFS should probably review what I have done.
[akpm@osdl.org: bugfix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Builds on ARM report link problems with common configurations like
statically linked NFS (for nfsroot). The symptom is that __init
section code references __exit section code; that won't work since
the exit sections are discarded (since they can never be called).
The best fix for these particular cases would be an "__init_or_exit"
section annotation.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As fs/nfs/inode.c is rather large, heterogenous and unwieldy, the attached
patch splits it up into a number of files:
(*) fs/nfs/inode.c
Strictly inode specific functions.
(*) fs/nfs/super.c
Superblock management functions for NFS and NFS4, normal access, clones
and referrals. The NFS4 superblock functions _could_ move out into a
separate conditionally compiled file, but it's probably not worth it as
there're so many common bits.
(*) fs/nfs/namespace.c
Some namespace-specific functions have been moved here.
(*) fs/nfs/nfs4namespace.c
NFS4-specific namespace functions (this could be merged into the previous
file). This file is conditionally compiled.
(*) fs/nfs/internal.h
Inter-file declarations, plus a few simple utility functions moved from
fs/nfs/inode.c.
Additionally, all the in-.c-file externs have been moved here, and those
files they were moved from now includes this file.
For the most part, the functions have not been changed, only some multiplexor
functions have changed significantly.
I've also:
(*) Added some extra banner comments above some functions.
(*) Rearranged the function order within the files to be more logical and
better grouped (IMO), though someone may prefer a different order.
(*) Reduced the number of #ifdefs in .c files.
(*) Added missing __init and __exit directives.
Signed-Off-By: David Howells <dhowells@redhat.com>
In the case of a call to truncate_inode_pages(), we should really try to
cancel any pending writes on the page.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up use of page_array, and fix an off-by-one error noticed by Tom
Talpey which causes kmalloc calls in cases where using the page_array
is sufficient.
Test plan:
Normal client functional testing with r/wsize=32768.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Modify well over a dozen mempool users to call mempool_create_slab_pool()
rather than calling mempool_create() with extra arguments, saving about 30
lines of code and increasing readability.
Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Kudos to Neil Brown for spotting the problem:
"in nfs_sync_inode, there is effectively the sequence:
nfs_wait_on_requests
nfs_flush_inode
nfs_commit_inode
This seems a bit racy to me as if the only requests are on the
->commit list, and nfs_commit_inode is called separately after
nfs_wait_on_requests completes, and before nfs_commit_inode start
(say: by nfs_write_inode) then none of these function will return
>0, yet there will be some pending request that aren't waited for."
The solution is to search for requests to wait upon, search for dirty
requests, and search for uncommitted requests while holding the
nfsi->req_lock
The patch also cleans up nfs_sync_inode(), getting rid of the redundant
FLUSH_WAIT flag. It turns out that we were always setting it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We don't need to set PG_private for readahead pages, since they never get
unlocked while I/O is in progress. However there is a small race in
nfs_readpage_release() whereby the page may be unlocked, and have
PG_private set.
Fix is to have PG_private set only for the case of writes...
Also fix a bug in nfs_clear_page_writeback(): Don't attempt to clear the
radix_tree tag if we've already deleted the radix tree entry.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Duplicate infrastructure from direct read path that will allow write
path to generate multiple write requests concurrently. This will
enable us to add support for aio in this path.
Temporarily we will lose the ability to do UNSTABLE writes followed by
a COMMIT in the direct write path. However, all applications I am
aware of that use NFS O_DIRECT currently write in relatively small
chunks, so this should not be inconvenient in any way.
Test plan:
Millions of fsx-odirect ops. OraSim.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch inverts the callback hierarchy for NFS write calls.
Instead of having the NFSv2/v3/v4-specific code set up the RPC callback
ops, we allow the original caller to do so. This allows for more
flexibility w.r.t. how to set up and tear down the nfs_write_data
structure while still allowing the NFSv3/v4 code to perform error
handling.
The greater flexibility is needed by the asynchronous O_DIRECT code, which
wants to be able to hold on to the original nfs_write_data structures after
the WRITE RPC call has completed in order to be able to replay them if the
COMMIT call determines that the server has rebooted.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Invoke the byte and event counter macros where we want to count bytes and
events.
Clean-up: fix a possible NULL dereference in nfs_lock, and simplify
nfs_file_open.
Test-plan:
fsx and iozone on UP and SMP systems, with and without pre-emption. Watch
for memory overwrite bugs, and performance loss (significantly more CPU
required per op).
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
this converts fs/nfs to kzalloc() usage.
compile tested with make allyesconfig
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
I've been reading through fs/nfs/write.c trying to track down a bug
that seems to be related to pages loosing a refcount and getting
freed too early (you interested in detail??) and I spotted a little
bug which the following patch should fix.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The SuS states that a call to write() will cause mtime to be updated on
the file. In order to satisfy that requirement, we need to flush out
any cached writes in nfs_getattr().
Speed things up slightly by not committing the writes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Most NFS server implementations allow up to 64KB reads and writes on the
wire. The Solaris NFS server allows up to a megabyte, for instance.
Now the Linux NFS client supports transfer sizes up to 1MB, too. This will
help reduce protocol and context switch overhead on read/write intensive NFS
workloads, and support larger atomic read and write operations on servers
that support them.
Test-plan:
Connectathon and iozone on mount point with wsize=rsize>32768 over TCP.
Tests with NFS over UDP to verify the maximum RPC payload size cap.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Shrink the RPC task structure. Instead of storing separate pointers
for task->tk_exit and task->tk_release, put them in a structure.
Also pass the user data pointer as a parameter instead of passing it via
task->tk_calldata. This enables us to nest callbacks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ensure that we always initiate flushing of data before we exit
a single-page ->writepage() call.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Ensure that we use set_page_writeback() in the appropriate places
to help the VM in keeping its page radix_tree in sync.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix some dprintk's so that NLM, NFS client, and RPC client compile
cleanly if CONFIG_SYSCTL is disabled.
Test plan:
Compile kernel with CONFIG_NFS enabled and CONFIG_SYSCTL disabled.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
RFC 3530 states that for OPEN_DOWNGRADE "The share_access and share_deny
bits specified must be exactly equal to the union of the share_access and
share_deny bits specified for some subset of the OPENs in effect for
current openowner on the current file.
Setattr is currently violating the NFSv4 rules for OPEN_DOWNGRADE in that
it may cause a downgrade from OPEN4_SHARE_ACCESS_BOTH to
OPEN4_SHARE_ACCESS_WRITE despite the fact that there exists no open file
with O_WRONLY access mode.
Fix the problem by replacing nfs4_find_state() with a modified version of
nfs_find_open_context().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Basically copies the VFS's method for tracking writebacks and applies
it to the struct nfs_page.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Instead of looking at whether or not the file is open for writes before
we accept to update the length using the server value, we should rather
be looking at whether or not we are currently caching any writes.
Failure to do so means in particular that we're not updating the file
length correctly after obtaining a POSIX or BSD lock.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Trond Myklebust