If we are doing a forced shutdown, we can get lots of noise about
delalloc pages being discarded. This is happens by design during a
forced shutdown, so don't spam the logs with these messages.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Re-apply a commit that had been reverted due to regressions
that have since been fixed.
From 95f8e302c0 Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@suse.de>
Date: Tue, 6 Jan 2009 14:43:09 +1100
Implement XFS's large buffer support with the new vmap APIs. See the vmap
rewrite (db64fe02) for some numbers. The biggest improvement that comes from
using the new APIs is avoiding the global KVA allocation lock on every call.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Only modifications here were a minor reformat, plus making the patch
apply given the new use of xfs_buf_is_vmapped().
Modified-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Re-apply a commit that had been reverted due to regressions
that have since been fixed.
Original commit: d2859751cd
Author: Nick Piggin <npiggin@suse.de>
Date: Tue, 6 Jan 2009 14:40:44 +1100
XFS's vmap batching simply defers a number (up to 64) of vunmaps,
and keeps track of them in a list. To purge the batch, it just goes
through the list and calls vunamp on each one. This is pretty poor:
a global TLB flush is generally still performed on each vunmap, with
the most expensive parts of the operation being the broadcast IPIs
and locking involved in the SMP callouts, and the locking involved
in the vmap management -- none of these are avoided by just batching
up the calls. I'm actually surprised it ever made much difference.
(Now that the lazy vmap allocator is upstream, this description is
not quite right, but the vunmap batching still doesn't seem to do
much).
Rip all this logic out of XFS completely. I will improve vmap
performance and scalability directly in subsequent patch.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
The only change I made was to use the "new" xfs_buf_is_vmapped()
function in a place it had been open-coded in the original.
Modified-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (21 commits)
xfs: return inode fork offset in bulkstat for fsr
xfs: Increase the default size of the reserved blocks pool
xfs: truncate delalloc extents when IO fails in writeback
xfs: check for more work before sleeping in xfssyncd
xfs: Fix a build warning in xfs_aops.c
xfs: fix locking for inode cache radix tree tag updates
xfs: remove xfs_ipin/xfs_iunpin
xfs: cleanup xfs_iunpin_wait/xfs_iunpin_nowait
xfs: kill xfs_lrw.h
xfs: factor common xfs_trans_bjoin code
xfs: stop passing opaque handles to xfs_log.c routines
xfs: split xfs_bmap_btalloc
xfs: fix xfs_fsblock_t tracing
xfs: fix inode pincount check in fsync
xfs: Non-blocking inode locking in IO completion
xfs: implement optimized fdatasync
xfs: remove wrapper for the fsync file operation
xfs: remove wrappers for read/write file operations
xfs: merge xfs_lrw.c into xfs_file.c
xfs: fix dquota trace format
...
* 'for-2.6.34' of git://linux-nfs.org/~bfields/linux: (22 commits)
nfsd4: fix minor memory leak
svcrpc: treat uid's as unsigned
nfsd: ensure sockets are closed on error
Revert "sunrpc: move the close processing after do recvfrom method"
Revert "sunrpc: fix peername failed on closed listener"
sunrpc: remove unnecessary svc_xprt_put
NFSD: NFSv4 callback client should use RPC_TASK_SOFTCONN
xfs_export_operations.commit_metadata
commit_metadata export operation replacing nfsd_sync_dir
lockd: don't clear sm_monitored on nsm_reboot_lookup
lockd: release reference to nsm_handle in nlm_host_rebooted
nfsd: Use vfs_fsync_range() in nfsd_commit
NFSD: Create PF_INET6 listener in write_ports
SUNRPC: NFS kernel APIs shouldn't return ENOENT for "transport not found"
SUNRPC: Bury "#ifdef IPV6" in svc_create_xprt()
NFSD: Support AF_INET6 in svc_addsock() function
SUNRPC: Use rpc_pton() in ip_map_parse()
nfsd: 4.1 has an rfc number
nfsd41: Create the recovery entry for the NFSv4.1 client
nfsd: use vfs_fsync for non-directories
...
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: (33 commits)
quota: stop using QUOTA_OK / NO_QUOTA
dquot: cleanup dquot initialize routine
dquot: move dquot initialization responsibility into the filesystem
dquot: cleanup dquot drop routine
dquot: move dquot drop responsibility into the filesystem
dquot: cleanup dquot transfer routine
dquot: move dquot transfer responsibility into the filesystem
dquot: cleanup inode allocation / freeing routines
dquot: cleanup space allocation / freeing routines
ext3: add writepage sanity checks
ext3: Truncate allocated blocks if direct IO write fails to update i_size
quota: Properly invalidate caches even for filesystems with blocksize < pagesize
quota: generalize quota transfer interface
quota: sb_quota state flags cleanup
jbd: Delay discarding buffers in journal_unmap_buffer
ext3: quota_write cross block boundary behaviour
quota: drop permission checks from xfs_fs_set_xstate/xfs_fs_set_xquota
quota: split out compat_sys_quotactl support from quota.c
quota: split out netlink notification support from quota.c
quota: remove invalid optimization from quota_sync_all
...
Fixed trivial conflicts in fs/namei.c and fs/ufs/inode.c
This gives the filesystem more information about the writeback that
is happening. Trond requested this for the NFS unstable write handling,
and other filesystems might benefit from this too by beeing able to
distinguish between the different callers in more detail.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Similar to the fsync issue fixed a while ago in commit
2daea67e96 we need to write for data to
actually hit the disk before writing out the metadata to guarantee
data integrity for filesystems that modify the inode in the data I/O
completion path. Currently XFS and NFS handle this manually, and AFS
has a write_inode method that does nothing but waiting for data, while
others are possibly missing out on this.
Fortunately this change has a lot less impact than the fsync change
as none of the write_inode methods starts data writeout of any form
by itself.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
So that fsr can attempt to get the fork offset of the temporary
inode it uses the same as the inode it is defragmenting, pass the
fork offset out in the bulkstat information.
The bulkstat structure has padding that has always been zeroed, so
userspace can tell if this field is set or not by use of the xattr
present flag and a non-zero value for the fork offset.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
The current default size of the reserved blocks pool is easy to deplete
with certain workloads, in particular workloads that do lots of concurrent
delayed allocation extent conversions. If enough transactions are running
in parallel and the entire pool is consumed then subsequent calls to
xfs_trans_reserve() will fail with ENOSPC. Also add a rate limited
warning so we know if this starts happening again.
This is an updated version of an old patch from Lachlan McIlroy.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
We currently use block_invalidatepage() to clean up pages where I/O
fails in ->writepage(). Unfortunately, if the page has delalloc
regions on it, we fail to remove the delalloc regions when we
invalidate the page. This can result in tripping a BUG() in
xfs_get_blocks() later on if a direct IO read is done on that same
region - the delalloc extent is returned when none is supposed to be
there.
Fix this by truncating away the delalloc regions on the page before
invalidating it. Because they are delalloc, we can do this without
needing a transaction. Indeed - if we get ENOSPC errors, we have to
be able to do this truncation without a transaction as there is
no space left for block reservation (typically why we see a ENOSPC
in writeback).
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
xfssyncd processes a queue of work by detaching the queue and
then iterating over all the work items. It then sleeps for a
time period or until new work comes in. If new work is queued
while xfssyncd is actively processing the detached work queue,
it will not process that new work until after a sleep timeout
or the next work event queued wakes it.
Fix this by checking the work queue again before going to sleep.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Fix a build warning that slipped through. Dave Chinner had posted
an updated version of his patch but the previous version--without
this fix--was what got committed.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Currently Q_XQUOTASYNC calls into the quota_sync method, but XFS does something
entirely different in it than the rest of the filesystems. xfs_quota which
calls Q_XQUOTASYNC expects an asynchronous data writeout to flush delayed
allocations, while the "VFS" quota support wants to flush changes to the quota
file.
So make Q_XQUOTASYNC call into the writeback code directly and make the
quota_sync method optional as XFS doesn't need in the sense expected by the
rest of the quota code.
GFS2 was using limited XFS-style quota and has a quota_sync method fitting
neither the style used by vfs_quota_sync nor xfs_fs_quota_sync. I left it
in for now as per discussion with Steve it expects to be called from the
sync path this way.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
The radix-tree code requires it's users to serialize tag updates
against other updates to the tree. While XFS protects tag updates
against each other it does not serialize them against updates of the
tree contents, which can lead to tag corruption. Fix the inode
cache to always take pag_ici_lock in exclusive mode when updating
radix tree tags.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Patrick Schreurs <patrick@news-service.com>
Tested-by: Patrick Schreurs <patrick@news-service.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Inodes are only pinned/unpinned via the inode item methods, and lots of
code relies on that fact. So remove the separate xfs_ipin/xfs_iunpin
helpers and merge them into their only callers. This also fixes up
various duplicate and/or incorrect comments.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Remove the inode item pointer and ili_last_lsn checks in
__xfs_iunpin_wait as any pinned inode is guaranteed to have them
valid. After this the xfs_iunpin_nowait case is nothing more than a
xfs_log_force_lsn, as we know that the caller has already checked
the pincount.
Make xfs_iunpin_nowait the new low-level routine just doing the log
force and rewrite xfs_iunpin_wait around it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Move the two declarations to better fitting headers now that
xfs_lrw.c is gone.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Most of xfs_trans_bjoin is duplicated in xfs_trans_get_buf,
xfs_trans_getsb and xfs_trans_read_buf. Add a new _xfs_trans_bjoin
which can be called by all four functions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Currenly we pass opaque xfs_log_ticket_t handles instead of
struct xlog_ticket pointers, and void pointers instead of
struct xlog_in_core pointers to various log manager functions.
Instead pass properly typed pointers after adding forward
declarations for them to xfs_log.h, and adjust the touched
function prototypes to the standard XFS style while at it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Split out the nullfb case into a separate function to reduce the stack
footprint and make the code more readable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Using a static buffer in xfs_fmtfsblock means we can corrupt traces if
multiple CPUs hit this code path at the same. Just remove xfs_fmtfsblock
for now and print the block number purely numerical. If we want the
NULLFSBLOCK and NULLSTARTBLOCK formatting back the best way would be
a decoding plugin in the trace-cmd userspace command.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
We need to hold the ilock to check the inode pincount safely. While
we're at it also remove the check for ip->i_itemp->ili_last_lsn, a
pinned inode always has it set.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
The introduction of barriers to loop devices has created a new IO
order completion dependency that XFS does not handle. The loop
device implements barriers using fsync and so turns a log IO in the
XFS filesystem on the loop device into a data IO in the backing
filesystem. That is, the completion of log IOs in the loop
filesystem are now dependent on completion of data IO in the backing
filesystem.
This can cause deadlocks when a flush daemon issues a log force with
an inode locked because the IO completion of IO on the inode is
blocked by the inode lock. This in turn prevents further data IO
completion from occuring on all XFS filesystems on that CPU (due to
the shared nature of the completion queues). This then prevents the
log IO from completing because the log is waiting for data IO
completion as well.
The fix for this new completion order dependency issue is to make
the IO completion inode locking non-blocking. If the inode lock
can't be grabbed, simply requeue the IO completion back to the work
queue so that it can be processed later. This prevents the
completion queue from being blocked and allows data IO completion on
other inodes to proceed, hence avoiding completion order dependent
deadlocks.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Allow us to track the difference between timestamp and size updates
by using mark_inode_dirty from the I/O completion code, and checking
the VFS inode flags in xfs_file_fsync.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Currently the fsync file operation is divided into a low-level
routine doing all the work and one that implements the Linux file
operation and does minimal argument wrapping. This is a leftover
from the days of the vnode operations layer and can be removed to
simplify the code a bit, as well as preparing for the implementation
of an optimized fdatasync which needs to look at the Linux inode
state.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Currently the aio_read, aio_write, splice_read and splice_write file
operations are divided into a low-level routine doing all the work
and one that implements the Linux file operations and does minimal
argument wrapping. This is a leftover from the days of the vnode
operations layer and can be removed to simplify the code a lot.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Currently the code to implement the file operations is split over
two small files. Merge the content of xfs_lrw.c into xfs_file.c to
have it in one place. Note that I haven't done various cleanups
that are possible after this yet, they will follow in the next
patch. Also the function xfs_dev_is_read_only which was in
xfs_lrw.c before really doesn't fit in here at all and was moved to
xfs_mount.c.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
The be32_to_cpu in the TP_printk output breaks automatic parsing of
the trace format by the trace-cmd tools, so we have to move it into
the TP_assign block. While we're at it also fix the format for the
quota limits to more regular and easier parseable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
While doing some testing of readdir perf a while back,
I noticed that the buffer size we're using internally is
smaller than what glibc gives us by default. Upping this
size helped a bit, and seems safe.
glibc's __alloc_dir() does:
const size_t default_allocation = (4 * BUFSIZ < sizeof (struct dirent64)
? sizeof (struct dirent64) : 4 * BUFSIZ);
const size_t small_allocation = (BUFSIZ < sizeof (struct dirent64)
? sizeof (struct dirent64) : BUFSIZ);
size_t allocation = default_allocation;
#ifdef _STATBUF_ST_BLKSIZE
if (statp != NULL && default_allocation < statp->st_blksize)
allocation = statp->st_blksize;
#endif
and
#define _G_BUFSIZ 8192
#define _IO_BUFSIZ _G_BUFSIZ
# define BUFSIZ _IO_BUFSIZ
so the default buffer is 4 * 8192 = 32768
(except in the unlikely case of blocks > 32k....)
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (52 commits)
fs/xfs: Correct NULL test
xfs: optimize log flushing in xfs_fsync
xfs: only clear the suid bit once in xfs_write
xfs: kill xfs_bawrite
xfs: log changed inodes instead of writing them synchronously
xfs: remove invalid barrier optimization from xfs_fsync
xfs: kill the unused XFS_QMOPT_* flush flags V2
xfs: Use delay write promotion for dquot flushing
xfs: Sort delayed write buffers before dispatch
xfs: Don't issue buffer IO direct from AIL push V2
xfs: Use delayed write for inodes rather than async V2
xfs: Make inode reclaim states explicit
xfs: more reserved blocks fixups
xfs: turn off sign warnings
xfs: don't hold onto reserved blocks on remount,ro
xfs: quota limit statvfs available blocks
xfs: replace KM_LARGE with explicit vmalloc use
xfs: cleanup up xfs_log_force calling conventions
xfs: kill XLOG_VEC_SET_TYPE
xfs: remove duplicate buffer flags
...
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/xfs-vipt:
xfs: fix xfs to work with Virtually Indexed architectures
sh: add mm API for DMA to vmalloc/vmap areas
arm: add mm API for DMA to vmalloc/vmap areas
parisc: add mm API for DMA to vmalloc/vmap areas
mm: add coherence API for DMA to vmalloc/vmap areas
This is the commit_metadata export operation for XFS.
- Takes one inode to be committed.
- Forces the log up to the lsn of the inode.
- Doesn't force the log if the inode doesn't have a pincount.
Signed-off-by: Ben Myers <bpm@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
[bfields@citi.umich.edu: trivial whitespace fix]
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Add __percpu sparse annotations to fs.
These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Test the value that was just allocated rather than the previously tested one.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r@
expression *x;
expression e;
identifier l;
@@
if (x == NULL || ...) {
... when forall
return ...; }
... when != goto l;
when != x = e
when != &x
*x == NULL
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
If we have a pinned inode it must have a log item attached to it.
Usually that log item will have ili_last_lsn already set, in which
case we only need to flush the log up to that LSN instead of doing a
full log force. This gives speedups of about 5% in some fsync heavy
workloads.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
file_remove_suid already calls into ->setattr to clear the suid and
sgid bits if needed, no need to start a second transaction to do it
ourselves.
Note that xfs_write_clear_setuid issues a sync transaction while the
path through ->setattr doesn't, but that is consistant with the
other filesystems.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
xfs_buf.c includes what is essentially a hand rolled version of
blk_rq_map_kern(). In order to work properly with the vmalloc buffers
that xfs uses, this hand rolled routine must also implement the flushing
API for vmap/vmalloc areas.
[style updates from hch@lst.de]
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
There are no more users of this function left in the XFS code
now that we've switched everything to delayed write flushing.
Remove it.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When an inode has already be flushed delayed write,
xfs_inode_clean() returns true and hence xfs_fs_write_inode() can
return on a synchronous inode write without having written the
inode. Currently these sycnhronous writes only come sync(1),
unmount, a sycnhronous NFS export and cachefiles so should be
relatively rare and out of common performance paths.
Realistically, a synchronous inode write is not necessary here; we
can avoid writing the inode by logging any non-transactional changes
that are pending. This needs to be done with synchronous
transactions, but it avoids seeking between the log and inode
clusters as we do now. We don't force the log if the inode is
pinned, though, so this differs from the fsync case. For normal
sys_sync and unmount behaviour this is fine because we do a
synchronous log force in xfs_sync_data which is called from the
->sync_fs code.
It does however break the NFS synchronous export guarantees for now,
but work is under way to fix this at a higher level or for the
higher level to provide an additional flag in the writeback control
to tell us that a log force is needed.
Portions of this patch are based on work from Dave Chinner.
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
We always need to flush the disk write cache and can't skip it just because
the no inode attributes have changed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
dquots are never flushed asynchronously. Remove the flag and the
async write support from the flush function. Make the default flush
a delwri flush to make the inode flush code, which leaves the
XFS_QMOPT_SYNC the only flag remaining. Convert that to use
SYNC_WAIT instead, just like the inode flush code.
V2:
- just pass flush flags straight through
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
xfs_qm_dqflock_pushbuf_wait() does a very similar trick to item
pushing used to do to flush out delayed write dquot buffers. Change
it to use the new promotion method rather than an async flush.
Also, xfs_qm_dqflock_pushbuf_wait() can return without the flush lock
held, yet the callers make the assumption that after this call the
flush lock is held. Always return with the flush lock held.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Currently when the xfsbufd writes delayed write buffers, it pushes
them to disk in the order they come off the delayed write list. If
there are lots of buffers ѕpread widely over the disk, this results
in overwhelming the elevator sort queues in the block layer and we
end up losing the posibility of merging adjacent buffers to minimise
the number of IOs.
Use the new generic list_sort function to sort the delwri dispatch
queue before issue to ensure that the buffers are pushed in the most
friendly order possible to the lower layers.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
All buffers logged into the AIL are marked as delayed write.
When the AIL needs to push the buffer out, it issues an async write of the
buffer. This means that IO patterns are dependent on the order of
buffers in the AIL.
Instead of flushing the buffer, promote the buffer in the delayed
write list so that the next time the xfsbufd is run the buffer will
be flushed by the xfsbufd. Return the state to the xfsaild that the
buffer was promoted so that the xfsaild knows that it needs to cause
the xfsbufd to run to flush the buffers that were promoted.
Using the xfsbufd for issuing the IO allows us to dispatch all
buffer IO from the one queue. This means that we can make much more
enlightened decisions on what order to flush buffers to disk as
we don't have multiple places issuing IO. Optimisations to xfsbufd
will be in a future patch.
Version 2
- kill XFS_ITEM_FLUSHING as it is now unused.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
We currently do background inode flush asynchronously, resulting in
inodes being written in whatever order the background writeback
issues them. Not only that, there are also blocking and non-blocking
asynchronous inode flushes, depending on where the flush comes from.
This patch completely removes asynchronous inode writeback. It
removes all the strange writeback modes and replaces them with
either a synchronous flush or a non-blocking delayed write flush.
That is, inode flushes will only issue IO directly if they are
synchronous, and background flushing may do nothing if the operation
would block (e.g. on a pinned inode or buffer lock).
Delayed write flushes will now result in the inode buffer sitting in
the delwri queue of the buffer cache to be flushed by either an AIL
push or by the xfsbufd timing out the buffer. This will allow
accumulation of dirty inode buffers in memory and allow optimisation
of inode cluster writeback at the xfsbufd level where we have much
greater queue depths than the block layer elevators. We will also
get adjacent inode cluster buffer IO merging for free when a later
patch in the series allows sorting of the delayed write buffers
before dispatch.
This effectively means that any inode that is written back by
background writeback will be seen as flush locked during AIL
pushing, and will result in the buffers being pushed from there.
This writeback path is currently non-optimal, but the next patch
in the series will fix that problem.
A side effect of this delayed write mechanism is that background
inode reclaim will no longer directly flush inodes, nor can it wait
on the flush lock. The result is that inode reclaim must leave the
inode in the reclaimable state until it is clean. Hence attempts to
reclaim a dirty inode in the background will simply skip the inode
until it is clean and this allows other mechanisms (i.e. xfsbufd) to
do more optimal writeback of the dirty buffers. As a result, the
inode reclaim code has been rewritten so that it no longer relies on
the ambiguous return values of xfs_iflush() to determine whether it
is safe to reclaim an inode.
Portions of this patch are derived from patches by Christoph
Hellwig.
Version 2:
- cleanup reclaim code as suggested by Christoph
- log background reclaim inode flush errors
- just pass sync flags to xfs_iflush
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
