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>
Hi.
I've been looking at a bugzilla which describes a problem where
a customer was advised to use either the "noac" or "actimeo=0"
mount options to solve a consistency problem that they were
seeing in the file attributes. It turned out that this solution
did not work reliably for them because sometimes, the local
attribute cache was believed to be valid and not timed out.
(With an attribute cache timeout of 0, the cache should always
appear to be timed out.)
In looking at this situation, it appears to me that the problem
is that the attribute cache timeout code has an off-by-one
error in it. It is assuming that the cache is valid in the
region, [read_cache_jiffies, read_cache_jiffies + attrtimeo]. The
cache should be considered valid only in the region,
[read_cache_jiffies, read_cache_jiffies + attrtimeo). With this
change, the options, "noac" and "actimeo=0", work as originally
expected.
This problem was previously addressed by special casing the
attrtimeo == 0 case. However, since the problem is only an off-
by-one error, the cleaner solution is address the off-by-one
error and thus, not require the special case.
Thanx...
ps
Signed-off-by: Peter Staubach <staubach@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: The nfs_mount() function is not to be used outside of the
NFS client. Move its public declaration to fs/nfs/internal.h.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
As not all files have an associated open_context (e.g. device special
files), it is safest to test for the existence of the open context
before de-referencing it.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It appears that 'jiffies' timestamps do not have high enough resolution for
nfs_inode_attrs_need_update(). One problem is that a GETATTR can be
launched within < 1 jiffy of the last operation that updated the attribute.
Another problem is that RPC calls can take < 1 jiffy to execute.
We can fix this by switching the variables to use a simple global counter
that gets incremented every time we start another GETATTR call.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, if two processes are both trying to revalidate metadata for the
same inode, they will find themselves being serialised. There is no good
justification for this now that we have improved our ability to detect
stale attribute data, so we should remove that serialisation.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
fs.h needs path.h, not namei.h; nfs_fs.h doesn't need it at all.
Several places in the tree needed direct include.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* kill nameidata * argument; map the 3 bits in ->flags anybody cares
about to new MAY_... ones and pass with the mask.
* kill redundant gfs2_iop_permission()
* sanitize ecryptfs_permission()
* fix remaining places where ->permission() instances might barf on new
MAY_... found in mask.
The obvious next target in that direction is permission(9)
folded fix for nfs_permission() breakage from Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Move the UDP/TCP default timeo/retrans settings for text mounts to
nfs_init_timeout_values(), which was were they were always being
initialised (and sanity checked) for binary mounts.
Document the default timeout values using appropriate #defines.
Ensure that we initialise and sanity check the transport protocols that
may have been specified by the user.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When we detect that we've crossed a mountpoint on the remote server, we
must take care not to use that inode to revalidate the fsid on our
current superblock. To do so, we label the inode as a remote mountpoint,
and check for that in nfs_update_inode().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* '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..
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>
lookup() and sillyrename() can race one another because the sillyrename()
completion cannot take the parent directory's inode->i_mutex since the
latter may be held by whoever is calling dput().
We therefore have little option but to add extra locking to ensure that
nfs_lookup() and nfs_atomic_open() do not race with the sillyrename
completion.
If somebody has looked up the sillyrenamed file in the meantime, we just
transfer the sillydelete information to the new dentry.
Please refer to the bug-report at
http://bugzilla.linux-nfs.org/show_bug.cgi?id=150
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This boot parameter will allow legacy 32-bit applications which call stat()
to continue to function even if the NFSv3/v4 server uses 64-bit inode
numbers.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Hi,
This patch cleans up duplicate includes in
include/linux/nfs_fs.h
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
- NFS_READTIME, NFS_CHANGE_ATTR are completely unused.
- Inline the few remaining uses of NFS_ATTRTIMEO, and remove.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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>
The fact that we're in the process of modifying the inode does not mean
that we should not invalidate the attribute and data caches. The defensive
thing is to always invalidate when we're confronted with inode
mtime/ctime or change_attribute updates that we do not immediately
recognise.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We don't care about whether or not some other process on our client is
changing the directory while we're in nfs_lookup_revalidate(), because the
dcache will take care of ensuring local atomicity.
We can therefore remove the test for nfs_caches_unstable().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFSv2 and v4 don't offer weak cache consistency attributes on WRITE calls.
In NFSv3, returning wcc data is optional. In all cases, we want to prevent
the client from invalidating our cached data whenever ->write_done()
attempts to update the inode attributes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFSv3 will correctly update atime on a readdir call, so there is no need to
set the NFS_INO_INVALID_ATIME flag unless the call to nfs_refresh_inode()
fails.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The reason is that if the weak cache consistency update was successful,
then we know that our client must be the only one that changed the
directory, and we've already updated the dcache to reflect the change.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We always want to check that the verifier and directory
cache_change_attribute match. This also allows us to remove the 'wraparound
hack' for the cache_change_attribute. If we're only checking for equality,
then we don't care about wraparound issues.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently, _nfs4_do_access() is just a copy of nfs_do_access() with added
conversion of the open flags into an access mask. This patch merges the
duplicate functionality.
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>
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>
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>
We need to grab the inode->i_lock atomically with the last reference put in
order to remove the open context that is being freed from the
nfsi->open_files list.
Fix by converting the kref to a standard atomic counter and then using
atomic_dec_and_lock()...
Thanks to Arnd Bergmann for pointing out the problem.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fix a couple of bugs:
- Don't rely on the parent dentry still being valid when the call completes.
Fixes a race with shrink_dcache_for_umount_subtree()
- Don't remove the file if the filehandle has been labelled as stale.
Fix a couple of inefficiencies
- Remove the global list of sillyrenamed files. Instead we can cache the
sillyrename information in the dentry->d_fsdata
- Move common code from unlink_setup/unlink_done into fs/nfs/unlink.c
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
In preparation for supporting NFSv2 and NFSv3 mount option handling in the
kernel NFS client, convert mount_clnt.c to be a permanent part of the NFS
client, instead of built only when CONFIG_ROOT_NFS is enabled.
In addition, we also replace the "struct sockaddr_in *" argument with
something more generic, to help support IPv6 at some later point.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Note to self: fix up /usr/sbin/rpcdebug too
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
