Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.
* blkdev_get/put() are the primary open and close functions.
* bd_claim/release() deal with exclusive open.
* open/close_bdev_exclusive() are combination of open and claim and
the other way around, respectively.
* bd_link/unlink_disk_holder() to create and remove holder/slave
symlinks.
* open_by_devnum() wraps bdget() + blkdev_get().
The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access. Reorganize the interface such that,
* blkdev_get() is extended to include exclusive access management.
@holder argument is added and, if is @FMODE_EXCL specified, it will
gain exclusive access atomically w.r.t. other exclusive accesses.
* blkdev_put() is similarly extended. It now takes @mode argument and
if @FMODE_EXCL is set, it releases an exclusive access. Also, when
the last exclusive claim is released, the holder/slave symlinks are
removed automatically.
* bd_claim/release() and close_bdev_exclusive() are no longer
necessary and either made static or removed.
* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
is no longer necessary and removed.
* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
and blkdev_get(). It also has an unexpected extra bdev_read_only()
test which probably should be moved into blkdev_get().
* open_by_devnum() is modified to take @holder argument and pass it to
blkdev_get().
Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should). This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.
open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features. Well, let's leave them for another day.
Most conversions are straight-forward. drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
__block_write_begin and block_prepare_write are identical except for slightly
different calling conventions. Convert all callers to the __block_write_begin
calling conventions and drop block_prepare_write.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (36 commits)
xfs: semaphore cleanup
xfs: Extend project quotas to support 32bit project ids
xfs: remove xfs_buf wrappers
xfs: remove xfs_cred.h
xfs: remove xfs_globals.h
xfs: remove xfs_version.h
xfs: remove xfs_refcache.h
xfs: fix the xfs_trans_committed
xfs: remove unused t_callback field in struct xfs_trans
xfs: fix bogus m_maxagi check in xfs_iget
xfs: do not use xfs_mod_incore_sb_batch for per-cpu counters
xfs: do not use xfs_mod_incore_sb for per-cpu counters
xfs: remove XFS_MOUNT_NO_PERCPU_SB
xfs: pack xfs_buf structure more tightly
xfs: convert buffer cache hash to rbtree
xfs: serialise inode reclaim within an AG
xfs: batch inode reclaim lookup
xfs: implement batched inode lookups for AG walking
xfs: split out inode walk inode grabbing
xfs: split inode AG walking into separate code for reclaim
...
Stop having two different names for many buffer functions and use
the more descriptive xfs_buf_* names directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
It used to have a place when it contained an automatically generated
CVS version, but these days it's entirely superflous.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Fail the mount if we can't allocate memory for the per-CPU counters.
This is consistent with how we handle everything else in the mount
path and makes the superblock counter modification a lot simpler.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Each buffer contains both a buftarg pointer and a mount pointer. If
we add a mount pointer into the buftarg, we can avoid needing the
b_mount field in every buffer and grab it from the buftarg when
needed instead. This shrinks the xfs_buf by 8 bytes.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Under heavy multi-way parallel create workloads, the VFS struggles
to write back all the inodes that have been changed in age order.
The bdi flusher thread becomes CPU bound, spending 85% of it's time
in the VFS code, mostly traversing the superblock dirty inode list
to separate dirty inodes old enough to flush.
We already keep an index of all metadata changes in age order - in
the AIL - and continued log pressure will do age ordered writeback
without any extra overhead at all. If there is no pressure on the
log, the xfssyncd will periodically write back metadata in ascending
disk address offset order so will be very efficient.
Hence we can stop marking VFS inodes dirty during transaction commit
or when changing timestamps during transactions. This will keep the
inodes in the superblock dirty list to those containing data or
unlogged metadata changes.
However, the timstamp changes are slightly more complex than this -
there are a couple of places that do unlogged updates of the
timestamps, and the VFS need to be informed of these. Hence add a
new function xfs_trans_ichgtime() for transactional changes,
and leave xfs_ichgtime() for the non-transactional changes.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
All the blkdev_issue_* helpers can only sanely be used for synchronous
caller. To issue cache flushes or barriers asynchronously the caller needs
to set up a bio by itself with a completion callback to move the asynchronous
state machine ahead. So drop the BLKDEV_IFL_WAIT flag that is always
specified when calling blkdev_issue_* and also remove the now unused flags
argument to blkdev_issue_flush and blkdev_issue_zeroout. For
blkdev_issue_discard we need to keep it for the secure discard flag, which
gains a more descriptive name and loses the bitops vs flag confusion.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
When we need to cover the log, we issue dummy transactions to ensure
the current log tail is on disk. Unfortunately we currently use the
root inode in the dummy transaction, and the act of committing the
transaction dirties the inode at the VFS level.
As a result, the VFS writeback of the dirty inode will prevent the
filesystem from idling long enough for the log covering state
machine to complete. The state machine gets stuck in a loop issuing
new dummy transactions to cover the log and never makes progress.
To avoid this problem, the dummy transactions should not cause
externally visible state changes. To ensure this occurs, make sure
that dummy transactions log an unchanging field in the superblock as
it's state is never propagated outside the filesystem. This allows
the log covering state machine to complete successfully and the
filesystem now correctly enters a fully idle state about 90s after
the last modification was made.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Because of delayed updates to sb_icount field in the super block, it
is possible to allocate over maxicount number of inodes. This
causes the arithmetic to calculate a negative number of free inodes
in user commands like df or stat -f.
Since maxicount is a somewhat arbitrary number, a slight over
allocation is not critical but user commands should be displayed as
0 or greater and never go negative. To do this the value in the
stats buffer f_ffree is capped to never go negative.
[ Modified to use max_t as per Christoph's comment. ]
Signed-off-by: Stu Brodsky <sbrodsky@sgi.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Since Linux 2.6.33 the kernel has support for real O_SYNC, which made
the osyncisosync option a no-op. Warn the users about this and remove
the mount flag for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
I missed Dave Chinner's second revision of this change, and pushed
his first version out to the repository instead.
commit a476c59ebb279d738718edc0e3fb76aab3687114
Author: Dave Chinner <dchinner@redhat.com>
This commit compensates for that by moving a block of code up a bit
further, with a result that matches the the effect of Dave's second
version.
Dave's first version was:
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Dave's second version was:
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Currently we don't remove the XFS mount from the shrinker list until
late in the unmount path. By this time, we have already torn down
the internals of the filesystem (e.g. the per-ag structures), and
hence if the shrinker is executed between the teardown and the
unregistering, the shrinker will get NULL per-ag structure pointers
and panic trying to dereference them.
Fix this by removing the xfs mount from the shrinker list before
tearing down it's internal structures.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Replace the xfs_itrace_entry catchall with specific trace points. For
most simple callers we now use the simple inode class, which used to
be the iget class, but add more details tracing for namespace events,
which now includes the name of the directory entries manipulated.
Remove the xfs_inactive trace point, which is a duplicate of the clear_inode
one, and the xfs_change_file_space trace point, which is immediately
followed by the more specific alloc/free space trace points.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
On the final put of a superblock the VFS already calls sync_filesystem
for us to write out all data and wait for it. No need to start another
asynchronous writeback inside ->put_super.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
We already rely on the fact that the sync code will cause a synchronous
log force later on (currently via xfs_fs_sync_fs -> xfs_quiesce_data ->
xfs_sync_data), so no need to do this here. This allows us to avoid
a lot of synchronous log forces during sync, which pays of especially
with delayed logging enabled. Some compilebench numbers that show
this:
xfs (delayed logging, 256k logbufs)
===================================
intial create 25.94 MB/s 25.75 MB/s 25.64 MB/s
create 8.54 MB/s 9.12 MB/s 9.15 MB/s
patch 2.47 MB/s 2.47 MB/s 3.17 MB/s
compile 29.65 MB/s 30.51 MB/s 27.33 MB/s
clean 90.92 MB/s 98.83 MB/s 128.87 MB/s
read tree 11.90 MB/s 11.84 MB/s 8.56 MB/s
read compiled 28.75 MB/s 29.96 MB/s 24.25 MB/s
delete tree 8.39 seconds 8.12 seconds 8.46 seconds
delete compiled 8.35 seconds 8.44 seconds 5.11 seconds
stat tree 6.03 seconds 5.59 seconds 5.19 seconds
stat compiled tree 9.00 seconds 9.52 seconds 8.49 seconds
xfs + write_inode log_force removal
===================================
intial create 25.87 MB/s 25.76 MB/s 25.87 MB/s
create 15.18 MB/s 14.80 MB/s 14.94 MB/s
patch 3.13 MB/s 3.14 MB/s 3.11 MB/s
compile 36.74 MB/s 37.17 MB/s 36.84 MB/s
clean 226.02 MB/s 222.58 MB/s 217.94 MB/s
read tree 15.14 MB/s 15.02 MB/s 15.14 MB/s
read compiled tree 29.30 MB/s 29.31 MB/s 29.32 MB/s
delete tree 6.22 seconds 6.14 seconds 6.15 seconds
delete compiled tree 5.75 seconds 5.92 seconds 5.81 seconds
stat tree 4.60 seconds 4.51 seconds 4.56 seconds
stat compiled tree 4.07 seconds 3.87 seconds 3.96 seconds
In addition to that also remove the delwri inode flush that is unessecary
now that bulkstat is always coherent.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Currently we need to either call IHOLD or xfs_trans_ihold on an inode when
joining it to a transaction via xfs_trans_ijoin.
This patches instead makes xfs_trans_ijoin usable on it's own by doing
an implicity xfs_trans_ihold, which also allows us to drop the third
argument. For the case where we want to hold a reference on the inode
a xfs_trans_ijoin_ref wrapper is added which does the IHOLD and marks
the inode for needing an xfs_iput. In addition to the cleaner interface
to the caller this also simplifies the implementation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Currently we track log item descriptor belonging to a transaction using a
complex opencoded chunk allocator. This code has been there since day one
and seems to work around the lack of an efficient slab allocator.
This patch replaces it with dynamically allocated log item descriptors
from a dedicated slab pool, linked to the transaction by a linked list.
This allows to greatly simplify the log item descriptor tracking to the
point where it's just a couple hundred lines in xfs_trans.c instead of
a separate file. The external API has also been simplified while we're
at it - the xfs_trans_add_item and xfs_trans_del_item functions to add/
delete items from a transaction have been simplified to the bare minium,
and the xfs_trans_find_item function is replaced with a direct dereference
of the li_desc field. All debug code walking the list of log items in
a transaction is down to a simple list_for_each_entry.
Note that we could easily use a singly linked list here instead of the
double linked list from list.h as the fastpath only does deletion from
sequential traversal. But given that we don't have one available as
a library function yet I use the list.h functions for simplicity.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Dmapi support was never merged upstream, but we still have a lot of hooks
bloating XFS for it, all over the fast pathes of the filesystem.
This patch drops over 700 lines of dmapi overhead. If we'll ever get HSM
support in mainline at least the namespace events can be done much saner
in the VFS instead of the individual filesystem, so it's not like this
is much help for future work.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Now the shrinker passes us a context, wire up a shrinker context per
filesystem. This allows us to remove the global mount list and the
locking problems that introduced. It also means that a shrinker call
does not need to traverse clean filesystems before finding a
filesystem with reclaimable inodes. This significantly reduces
scanning overhead when lots of filesystems are present.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
The delayed logging code only changes in-memory structures and as
such can be enabled and disabled with a mount option. Add the mount
option and emit a warning that this is an experimental feature that
should not be used in production yet.
We also need infrastructure to track committed items that have not
yet been written to the log. This is what the Committed Item List
(CIL) is for.
The log item also needs to be extended to track the current log
vector, the associated memory buffer and it's location in the Commit
Item List. Extend the log item and log vector structures to enable
this tracking.
To maintain the current log format for transactions with delayed
logging, we need to introduce a checkpoint transaction and a context
for tracking each checkpoint from initiation to transaction
completion. This includes adding a log ticket for tracking space
log required/used by the context checkpoint.
To track all the changes we need an io vector array per log item,
rather than a single array for the entire transaction. Using the new
log vector structure for this requires two passes - the first to
allocate the log vector structures and chain them together, and the
second to fill them out. This log vector chain can then be passed
to the CIL for formatting, pinning and insertion into the CIL.
Formatting of the log vector chain is relatively simple - it's just
a loop over the iovecs on each log vector, but it is made slightly
more complex because we re-write the iovec after the copy to point
back at the memory buffer we just copied into.
This code also needs to pin log items. If the log item is not
already tracked in this checkpoint context, then it needs to be
pinned. Otherwise it is already pinned and we don't need to pin it
again.
The only other complexity is calculating the amount of new log space
the formatting has consumed. This needs to be accounted to the
transaction in progress, and the accounting is made more complex
becase we need also to steal space from it for log metadata in the
checkpoint transaction. Calculate all this at insert time and update
all the tickets, counters, etc correctly.
Once we've formatted all the log items in the transaction, attach
the busy extents to the checkpoint context so the busy extents live
until checkpoint completion and can be processed at that point in
time. Transactions can then be freed at this point in time.
Now we need to issue checkpoints - we are tracking the amount of log space
used by the items in the CIL, so we can trigger background checkpoints when the
space usage gets to a certain threshold. Otherwise, checkpoints need ot be
triggered when a log synchronisation point is reached - a log force event.
Because the log write code already handles chained log vectors, writing the
transaction is trivial, too. Construct a transaction header, add it
to the head of the chain and write it into the log, then issue a
commit record write. Then we can release the checkpoint log ticket
and attach the context to the log buffer so it can be called during
Io completion to complete the checkpoint.
We also need to allow for synchronising multiple in-flight
checkpoints. This is needed for two things - the first is to ensure
that checkpoint commit records appear in the log in the correct
sequence order (so they are replayed in the correct order). The
second is so that xfs_log_force_lsn() operates correctly and only
flushes and/or waits for the specific sequence it was provided with.
To do this we need a wait variable and a list tracking the
checkpoint commits in progress. We can walk this list and wait for
the checkpoints to change state or complete easily, an this provides
the necessary synchronisation for correct operation in both cases.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Clean up the buffer log format (XFS_BLI_*) flags because they have a
polluted namespace. They XFS_BLI_ prefix is used for both in-memory
and on-disk flag feilds, but have overlapping values for different
flags. Rename the buffer log format flags to use the XFS_BLF_*
prefix to avoid confusing them with the in-memory XFS_BLI_* prefixed
flags.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
We need to wait for all pending direct I/O requests before taking care of
metadata in fsync and write_inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
This allows to see in `ps` and similar tools which kthreads are
allotted to which block device/filesystem, similar to what jbd2
does. As the process name is a fixed 16-char array, no extra
space is needed in tasks.
PID TTY STAT TIME COMMAND
2 ? S 0:00 [kthreadd]
197 ? S 0:00 \_ [jbd2/sda2-8]
198 ? S 0:00 \_ [ext4-dio-unwrit]
204 ? S 0:00 \_ [flush-8:0]
2647 ? S 0:00 \_ [xfs_mru_cache]
2648 ? S 0:00 \_ [xfslogd/0]
2649 ? S 0:00 \_ [xfsdatad/0]
2650 ? S 0:00 \_ [xfsconvertd/0]
2651 ? S 0:00 \_ [xfsbufd/ram0]
2652 ? S 0:00 \_ [xfsaild/ram0]
2653 ? S 0:00 \_ [xfssyncd/ram0]
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
On low memory boxes or those with highmem, kernel can OOM before the
background reclaims inodes via xfssyncd. Add a shrinker to run inode
reclaim so that it inode reclaim is expedited when memory is low.
This is more complex than it needs to be because the VM folk don't
want a context added to the shrinker infrastructure. Hence we need
to add a global list of XFS mount structures so the shrinker can
traverse them.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
The patch just convert all blkdev_issue_xxx function to common
set of flags. Wait/allocation semantics preserved.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
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>
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 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>
This mangles the reserved blocks counts a little more.
1) add a helper function for the default reserved count
2) add helper functions to save/restore counts on ro/rw
3) save/restore reserved blocks on freeze/thaw
4) disallow changing reserved count while readonly
V2: changed field name to match Dave's changes
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Alex Elder <aelder@sgi.com>
If we hold onto reserved blocks when doing a remount,ro we end
up writing the blocks used count to disk that includes the reserved
blocks. Reserved blocks are not actually used, so this results in
the values in the superblock being incorrect.
Hence if we run xfs_check or xfs_repair -n while the filesystem is
mounted remount,ro we end up with an inconsistent filesystem being
reported. Also, running xfs_copy on the remount,ro filesystem will
result in an inconsistent image being generated.
To fix this, unreserve the blocks when doing the remount,ro, and
reserved them again on remount,rw. This way a remount,ro filesystem
will appear consistent on disk to all utilities.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Now that the AIL push algorithm is traversal safe, we don't need a
watchdog function in the xfsaild to catch pushes that fail to make
progress. Remove the watchdog timeout and make pushes purely driven
by demand. This will remove the once-per-second wakeup that is seen
when the filesystem is idle and make laptop power misers happy.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
We cannot do direct inode reclaim without taking the flush lock to
ensure that we do not reclaim an inode under IO. We check the inode
is clean before doing direct reclaim, but this is not good enough
because the inode flush code marks the inode clean once it has
copied the in-core dirty state to the backing buffer.
It is the flush lock that determines whether the inode is still
under IO, even though it is marked clean, and the inode is still
required at IO completion so we can't reclaim it even though it is
clean in core. Hence the requirement that we need to take the flush
lock even on clean inodes because this guarantees that the inode
writeback IO has completed and it is safe to reclaim the inode.
With delayed write inode flushing, we coul dend up waiting a long
time on the flush lock even for a clean inode. The background
reclaim already handles this efficiently, so avoid all the problems
by killing the direct reclaim path altogether.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Convert the old xfs tracing support that could only be used with the
out of tree kdb and xfsidbg patches to use the generic event tracer.
To use it make sure CONFIG_EVENT_TRACING is enabled and then enable
all xfs trace channels by:
echo 1 > /sys/kernel/debug/tracing/events/xfs/enable
or alternatively enable single events by just doing the same in one
event subdirectory, e.g.
echo 1 > /sys/kernel/debug/tracing/events/xfs/xfs_ihold/enable
or set more complex filters, etc. In Documentation/trace/events.txt
all this is desctribed in more detail. To reads the events do a
cat /sys/kernel/debug/tracing/trace
Compared to the last posting this patch converts the tracing mostly to
the one tracepoint per callsite model that other users of the new
tracing facility also employ. This allows a very fine-grained control
of the tracing, a cleaner output of the traces and also enables the
perf tool to use each tracepoint as a virtual performance counter,
allowing us to e.g. count how often certain workloads git various
spots in XFS. Take a look at
http://lwn.net/Articles/346470/
for some examples.
Also the btree tracing isn't included at all yet, as it will require
additional core tracing features not in mainline yet, I plan to
deliver it later.
And the really nice thing about this patch is that it actually removes
many lines of code while adding this nice functionality:
fs/xfs/Makefile | 8
fs/xfs/linux-2.6/xfs_acl.c | 1
fs/xfs/linux-2.6/xfs_aops.c | 52 -
fs/xfs/linux-2.6/xfs_aops.h | 2
fs/xfs/linux-2.6/xfs_buf.c | 117 +--
fs/xfs/linux-2.6/xfs_buf.h | 33
fs/xfs/linux-2.6/xfs_fs_subr.c | 3
fs/xfs/linux-2.6/xfs_ioctl.c | 1
fs/xfs/linux-2.6/xfs_ioctl32.c | 1
fs/xfs/linux-2.6/xfs_iops.c | 1
fs/xfs/linux-2.6/xfs_linux.h | 1
fs/xfs/linux-2.6/xfs_lrw.c | 87 --
fs/xfs/linux-2.6/xfs_lrw.h | 45 -
fs/xfs/linux-2.6/xfs_super.c | 104 ---
fs/xfs/linux-2.6/xfs_super.h | 7
fs/xfs/linux-2.6/xfs_sync.c | 1
fs/xfs/linux-2.6/xfs_trace.c | 75 ++
fs/xfs/linux-2.6/xfs_trace.h | 1369 +++++++++++++++++++++++++++++++++++++++++
fs/xfs/linux-2.6/xfs_vnode.h | 4
fs/xfs/quota/xfs_dquot.c | 110 ---
fs/xfs/quota/xfs_dquot.h | 21
fs/xfs/quota/xfs_qm.c | 40 -
fs/xfs/quota/xfs_qm_syscalls.c | 4
fs/xfs/support/ktrace.c | 323 ---------
fs/xfs/support/ktrace.h | 85 --
fs/xfs/xfs.h | 16
fs/xfs/xfs_ag.h | 14
fs/xfs/xfs_alloc.c | 230 +-----
fs/xfs/xfs_alloc.h | 27
fs/xfs/xfs_alloc_btree.c | 1
fs/xfs/xfs_attr.c | 107 ---
fs/xfs/xfs_attr.h | 10
fs/xfs/xfs_attr_leaf.c | 14
fs/xfs/xfs_attr_sf.h | 40 -
fs/xfs/xfs_bmap.c | 507 +++------------
fs/xfs/xfs_bmap.h | 49 -
fs/xfs/xfs_bmap_btree.c | 6
fs/xfs/xfs_btree.c | 5
fs/xfs/xfs_btree_trace.h | 17
fs/xfs/xfs_buf_item.c | 87 --
fs/xfs/xfs_buf_item.h | 20
fs/xfs/xfs_da_btree.c | 3
fs/xfs/xfs_da_btree.h | 7
fs/xfs/xfs_dfrag.c | 2
fs/xfs/xfs_dir2.c | 8
fs/xfs/xfs_dir2_block.c | 20
fs/xfs/xfs_dir2_leaf.c | 21
fs/xfs/xfs_dir2_node.c | 27
fs/xfs/xfs_dir2_sf.c | 26
fs/xfs/xfs_dir2_trace.c | 216 ------
fs/xfs/xfs_dir2_trace.h | 72 --
fs/xfs/xfs_filestream.c | 8
fs/xfs/xfs_fsops.c | 2
fs/xfs/xfs_iget.c | 111 ---
fs/xfs/xfs_inode.c | 67 --
fs/xfs/xfs_inode.h | 76 --
fs/xfs/xfs_inode_item.c | 5
fs/xfs/xfs_iomap.c | 85 --
fs/xfs/xfs_iomap.h | 8
fs/xfs/xfs_log.c | 181 +----
fs/xfs/xfs_log_priv.h | 20
fs/xfs/xfs_log_recover.c | 1
fs/xfs/xfs_mount.c | 2
fs/xfs/xfs_quota.h | 8
fs/xfs/xfs_rename.c | 1
fs/xfs/xfs_rtalloc.c | 1
fs/xfs/xfs_rw.c | 3
fs/xfs/xfs_trans.h | 47 +
fs/xfs/xfs_trans_buf.c | 62 -
fs/xfs/xfs_vnodeops.c | 8
70 files changed, 2151 insertions(+), 2592 deletions(-)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Stop the flag saving as we never mangle those in the unmount path, and
hide all the weird arguents to the dmapi code inside the
XFS_SEND_PREUNMOUNT / XFS_SEND_UNMOUNT macros.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
The iolock is used for protecting reads, writes and block truncates
against each other. We have two classes of callers, the first one is
induced by a file operation and requires a reference to the inode be
held and not dropped after the operation is done:
- xfs_vm_vmap, xfs_vn_fallocate, xfs_read, xfs_write, xfs_splice_read,
xfs_splice_write and xfs_setattr are all implementations of VFS
methods that require a live inode
- xfs_getbmap and xfs_swap_extents are ioctl subcommand for which the
same is true
- xfs_truncate_file is only called on quota inodes just returned from
xfs_iget
- xfs_sync_inode_data does the lock just after an igrab()
- xfs_filestream_associate and xfs_filestream_new_ag take the iolock
on the parent inode of an inode which by VFS rules must be referenced
And we have various calls to truncate blocks past EOF or the whole
file when dropping the last reference to an inode. Unfortunately
lockdep complains when we do memory allocations that can recurse into
the filesystem in the first class because the second class happens to
take the same lock. To avoid this re-init the iolock in the beginning
of xfs_fs_clear_inode to get a new lock class.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Currently the reclaim code for the case where we don't reclaim the
final reclaim is overly complicated. We know that the inode is clean
but instead of just directly reclaiming the clean inode we go through
the whole process of marking the inode reclaimable just to directly
reclaim it from the calling context. Besides being overly complicated
this introduces a race where iget could recycle an inode between
marked reclaimable and actually being reclaimed leading to panics.
This patch gets rid of the existing reclaim path, and replaces it with
a simple call to xfs_ireclaim if the inode was clean. While we're at
it we also use the slightly more lax xfs_inode_clean check we'd use
later to determine if we need to flush the inode here.
Finally get rid of xfs_reclaim function and place the remaining small
bits of reclaim code directly into xfs_fs_destroy_inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Patrick Schreurs <patrick@news-service.com>
Reported-by: Tommy van Leeuwen <tommy@news-service.com>
Tested-by: Patrick Schreurs <patrick@news-service.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Sort out ->sync_fs to not perform a superblock writeback for the wait = 0 case
as that is just an optional first pass and the superblock will be written back
properly in the next call with wait = 1. Instead perform an opportunistic
quota writeback to have less work later. Also remove the freeze special case
as we do a proper wait = 1 call in the freeze code anyway.
Also rename the function to xfs_fs_sync_fs to match the normal naming
convention, update comments and avoid calling into the laptop_mode logic on
an error.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
This is picking up on Felix's repost of Dave's patch to implement a
.dirty_inode method. We really need this notification because
the VFS keeps writing directly into the inode structure instead
of going through methods to update this state. In addition to
the long-known atime issue we now also have a caller in VM code
that updates c/mtime that way for shared writeable mmaps. And
I found another one that no one has noticed in practice in the FIFO
code.
So implement ->dirty_inode to set i_update_core whenever the
inode gets externally dirtied, and switch the c/mtime handling to
the same scheme we already use for atime (always picking up
the value from the Linux inode).
Note that this patch also removes the xfs_synchronize_atime call
in xfs_reclaim it was superflous as we already synchronize the time
when writing the inode via the log (xfs_inode_item_format) or the
normal buffers (xfs_iflush_int).
In addition also remove the I_CLEAR check before copying the Linux
timestamps - now that we always have the Linux inode available
we can always use the timestamps in it.
Also switch to just using file_update_time for regular reads/writes -
that will get us all optimization done to it for free and make
sure we notice early when it breaks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Tejun Heo
Al Viro
Christoph Hellwig
Linus Torvalds
Jens Axboe
Christoph Hellwig
Dave Chinner
Stuart Brodsky
Dave Chinner
Alex Elder
Jens Axboe
Jan Engelhardt
Dmitry Monakhov
Eric Sandeen
Alexey Dobriyan