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68 commits

Author SHA1 Message Date
Al Viro
4a0fd5bf0f teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long
... and convert a bunch of SYSCALL_DEFINE ones to SYSCALL_DEFINE<n>,
killing the boilerplate crap around them.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-03 22:46:22 -05:00
Al Viro
496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Al Viro
2903ff019b switch simple cases of fget_light to fdget
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 22:20:08 -04:00
Jan Kara
4ea425b63a vfs: Avoid unnecessary WB_SYNC_NONE writeback during sys_sync and reorder sync passes
wakeup_flusher_threads(0) will queue work doing complete writeback for each
flusher thread. Thus there is not much point in submitting another work doing
full inode WB_SYNC_NONE writeback by writeback_inodes_sb().

After this change it does not make sense to call nonblocking ->sync_fs and
block device flush before calling sync_inodes_sb() because
wakeup_flusher_threads() is completely asynchronous and thus these functions
would be called in parallel with inode writeback running which will effectively
void any work they do. So we move sync_inodes_sb() call before these two
functions.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22 23:59:01 +04:00
Jan Kara
d0e91b13eb vfs: Remove unnecessary flushing of block devices
It is not necessary to write block devices twice. The reason why we first did
flush and then proper sync is that
  for_each_bdev() {
    write_bdev()
    wait_for_completion()
  }
is much slower than
  for_each_bdev()
    write_bdev()
  for_each_bdev()
    wait_for_completion()
when there is bigger amount of data. But as is seen in the above, there's no real
need to scan pages and submit them twice. We just need to separate the submission
and waiting part. This patch does that.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22 23:58:53 +04:00
Jan Kara
a8c7176b6d vfs: Make sys_sync writeout also block device inodes
In case block device does not have filesystem mounted on it, sys_sync will just
ignore it and doesn't writeout its dirty pages. This is because writeback code
avoids writing inodes from superblock without backing device and
blockdev_superblock is such a superblock.  Since it's unexpected that sync
doesn't writeout dirty data for block devices be nice to users and change the
behavior to do so. So now we iterate over all block devices on blockdev_super
instead of iterating over all superblocks when syncing block devices.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22 23:58:49 +04:00
Jan Kara
b3de653105 vfs: Reorder operations during sys_sync
Change the order of operations during sync from

for_each_sb {
        writeback_inodes_sb();
        sync_fs(nowait);
        __sync_blockdev(nowait);
}
for_each_sb {
        sync_inodes_sb();
        sync_fs(wait);
        __sync_blockdev(wait);
}

to

for_each_sb
        writeback_inodes_sb();
for_each_sb
        sync_fs(nowait);
for_each_sb
        __sync_blockdev(nowait);
for_each_sb
        sync_inodes_sb();
for_each_sb
        sync_fs(wait);
for_each_sb
        __sync_blockdev(wait);

This is a preparation for the following patches in this series.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22 23:58:41 +04:00
Jan Kara
a117782571 quota: Move quota syncing to ->sync_fs method
Since the moment writes to quota files are using block device page cache and
space for quota structures is reserved at the moment they are first accessed we
have no reason to sync quota before inode writeback. In fact this order is now
only harmful since quota information can easily change during inode writeback
(either because conversion of delayed-allocated extents or simply because of
allocation of new blocks for simple filesystems not using page_mkwrite).

So move syncing of quota information after writeback of inodes into ->sync_fs
method. This way we do not have to use ->quota_sync callback which is primarily
intended for use by quotactl syscall anyway and we get rid of calling
->sync_fs() twice unnecessarily. We skip quota syncing for OCFS2 since it does
proper quota journalling in all cases (unlike ext3, ext4, and reiserfs which
also support legacy non-journalled quotas) and thus there are no dirty quota
structures.

CC: "Theodore Ts'o" <tytso@mit.edu>
CC: Joel Becker <jlbec@evilplan.org>
CC: reiserfs-devel@vger.kernel.org
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Dave Kleikamp <shaggy@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22 23:58:34 +04:00
Jan Kara
ceed17236a quota: Split dquot_quota_sync() to writeback and cache flushing part
Split off part of dquot_quota_sync() which writes dquots into a quota file
to a separate function. In the next patch we will use the function from
filesystems and we do not want to abuse ->quota_sync quotactl callback more
than necessary.

Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22 23:58:19 +04:00
Jan Kara
6eedc70150 vfs: Move noop_backing_dev_info check from sync into writeback
In principle, a filesystem may want to have ->sync_fs() called during sync(1)
although it does not have a bdi (i.e. s_bdi is set to noop_backing_dev_info).
Only writeback code really needs bdi set to something reasonable. So move the
checks where they are more logical.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-22 23:58:18 +04:00
Al Viro
c2bd6c11cd switch do_fsync() to fget_light()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-29 23:28:29 -04:00
Paul Gortmaker
630d9c4727 fs: reduce the use of module.h wherever possible
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include.  Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-28 19:31:58 -05:00
Al Viro
ff01bb4832 fs: move code out of buffer.c
Move invalidate_bdev, block_sync_page into fs/block_dev.c.  Export
kill_bdev as well, so brd doesn't have to open code it.  Reduce
buffer_head.h requirement accordingly.

Removed a rather large comment from invalidate_bdev, as it looked a bit
obsolete to bother moving.  The small comment replacing it says enough.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:07 -05:00
Curt Wohlgemuth
0e175a1835 writeback: Add a 'reason' to wb_writeback_work
This creates a new 'reason' field in a wb_writeback_work
structure, which unambiguously identifies who initiates
writeback activity.  A 'wb_reason' enumeration has been
added to writeback.h, to enumerate the possible reasons.

The 'writeback_work_class' and tracepoint event class and
'writeback_queue_io' tracepoints are updated to include the
symbolic 'reason' in all trace events.

And the 'writeback_inodes_sbXXX' family of routines has had
a wb_stats parameter added to them, so callers can specify
why writeback is being started.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-31 00:33:36 +08:00
Josef Bacik
02c24a8218 fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:59 -04:00
Linus Torvalds
6c51038900 Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
  Documentation/iostats.txt: bit-size reference etc.
  cfq-iosched: removing unnecessary think time checking
  cfq-iosched: Don't clear queue stats when preempt.
  blk-throttle: Reset group slice when limits are changed
  blk-cgroup: Only give unaccounted_time under debug
  cfq-iosched: Don't set active queue in preempt
  block: fix non-atomic access to genhd inflight structures
  block: attempt to merge with existing requests on plug flush
  block: NULL dereference on error path in __blkdev_get()
  cfq-iosched: Don't update group weights when on service tree
  fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
  block: Require subsystems to explicitly allocate bio_set integrity mempool
  jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  fs: make fsync_buffers_list() plug
  mm: make generic_writepages() use plugging
  blk-cgroup: Add unaccounted time to timeslice_used.
  block: fixup plugging stubs for !CONFIG_BLOCK
  block: remove obsolete comments for blkdev_issue_zeroout.
  blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
  ...

Fix up conflicts in fs/{aio.c,super.c}
2011-03-24 10:16:26 -07:00
Sage Weil
b7ed78f565 introduce sys_syncfs to sync a single file system
It is frequently useful to sync a single file system, instead of all
mounted file systems via sync(2):

 - On machines with many mounts, it is not at all uncommon for some of
   them to hang (e.g. unresponsive NFS server).  sync(2) will get stuck on
   those and may never get to the one you do care about (e.g., /).
 - Some applications write lots of data to the file system and then
   want to make sure it is flushed to disk.  Calling fsync(2) on each
   file introduces unnecessary ordering constraints that result in a large
   amount of sub-optimal writeback/flush/commit behavior by the file
   system.

There are currently two ways (that I know of) to sync a single super_block:

 - BLKFLSBUF ioctl on the block device: That also invalidates the bdev
   mapping, which isn't usually desirable, and doesn't work for non-block
   file systems.
 - 'mount -o remount,rw' will call sync_filesystem as an artifact of the
   current implemention.  Relying on this little-known side effect for
   something like data safety sounds foolish.

Both of these approaches require root privileges, which some applications
do not have (nor should they need?) given that sync(2) is an unprivileged
operation.

This patch introduces a new system call syncfs(2) that takes an fd and
syncs only the file system it references.  Maybe someday we can

 $ sync /some/path

and not get

 sync: ignoring all arguments

The syscall is motivated by comments by Al and Christoph at the last LSF.
syncfs(2) seems like an appropriate name given statfs(2).

A similar ioctl was also proposed a while back, see
	http://marc.info/?l=linux-fsdevel&m=127970513829285&w=2

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-21 00:40:29 -04:00
Jens Axboe
95f28604a6 fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
We don't have proper reference counting for this yet, so we run into
cases where the device is pulled and we OOPS on flushing the fs data.
This happens even though the dirty inodes have already been
migrated to the default_backing_dev_info.

Reported-by: Torsten Hilbrich <torsten.hilbrich@secunet.com>
Tested-by: Torsten Hilbrich <torsten.hilbrich@secunet.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-17 11:13:12 +01:00
Al Viro
b5fc510c48 get rid of file_fsync()
Copy and simplify in the only two users remaining.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:47:43 -04:00
Jens Axboe
b4ca761577 Merge branch 'master' into for-linus
Conflicts:
	fs/pipe.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-01 12:42:12 +02:00
Jens Axboe
0e3c9a2284 Revert "writeback: fix WB_SYNC_NONE writeback from umount"
This reverts commit e913fc825d.

We are investigating a hang associated with the WB_SYNC_NONE changes,
so revert them for now.

Conflicts:

	fs/fs-writeback.c
	mm/page-writeback.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-01 11:08:43 +02:00
Christoph Hellwig
7ea8085910 drop unused dentry argument to ->fsync
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-27 22:05:02 -04:00
Linus Torvalds
e8bebe2f71 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (69 commits)
  fix handling of offsets in cris eeprom.c, get rid of fake on-stack files
  get rid of home-grown mutex in cris eeprom.c
  switch ecryptfs_write() to struct inode *, kill on-stack fake files
  switch ecryptfs_get_locked_page() to struct inode *
  simplify access to ecryptfs inodes in ->readpage() and friends
  AFS: Don't put struct file on the stack
  Ban ecryptfs over ecryptfs
  logfs: replace inode uid,gid,mode initialization with helper function
  ufs: replace inode uid,gid,mode initialization with helper function
  udf: replace inode uid,gid,mode init with helper
  ubifs: replace inode uid,gid,mode initialization with helper function
  sysv: replace inode uid,gid,mode initialization with helper function
  reiserfs: replace inode uid,gid,mode initialization with helper function
  ramfs: replace inode uid,gid,mode initialization with helper function
  omfs: replace inode uid,gid,mode initialization with helper function
  bfs: replace inode uid,gid,mode initialization with helper function
  ocfs2: replace inode uid,gid,mode initialization with helper function
  nilfs2: replace inode uid,gid,mode initialization with helper function
  minix: replace inode uid,gid,mode init with helper
  ext4: replace inode uid,gid,mode init with helper
  ...

Trivial conflict in fs/fs-writeback.c (mark bitfields unsigned)
2010-05-21 19:37:45 -07:00
Christoph Hellwig
8018ab0574 sanitize vfs_fsync calling conventions
Now that the last user passing a NULL file pointer is gone we can remove
the redundant dentry argument and associated hacks inside vfs_fsynmc_range.

The next step will be removig the dentry argument from ->fsync, but given
the luck with the last round of method prototype changes I'd rather
defer this until after the main merge window.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:21 -04:00
Al Viro
01a05b337a new helper: iterate_supers()
... and switch the simple "loop over superblocks and do something"
loops to it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:16 -04:00
Al Viro
8edd64bd60 get rid of restarts in sync_filesystems()
At the same time we can kill s_need_restart and local mutex in there.
__put_super() made public for a while; will be gone later.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:15 -04:00
Al Viro
551de6f34d Leave superblocks on s_list until the end
We used to remove from s_list and s_instances at the same
time.  So let's *not* do the former and skip superblocks
that have empty s_instances in the loops over s_list.

The next step, of course, will be to get rid of rescan logics
in those loops.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:14 -04:00
Jens Axboe
e913fc825d writeback: fix WB_SYNC_NONE writeback from umount
When umount calls sync_filesystem(), we first do a WB_SYNC_NONE
writeback to kick off writeback of pending dirty inodes, then follow
that up with a WB_SYNC_ALL to wait for it. Since umount already holds
the sb s_umount mutex, WB_SYNC_NONE ends up doing nothing and all
writeback happens as WB_SYNC_ALL. This can greatly slow down umount,
since WB_SYNC_ALL writeback is a data integrity operation and thus
a bigger hammer than simple WB_SYNC_NONE. For barrier aware file systems
it's a lot slower.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-05-17 12:55:07 +02:00
Jörn Engel
5129a469a9 Catch filesystems lacking s_bdi
noop_backing_dev_info is used only as a flag to mark filesystems that
don't have any backing store, like tmpfs, procfs, spufs, etc.

Signed-off-by: Joern Engel <joern@logfs.org>

Changed the BUG_ON() to a WARN_ON(). Note that adding dirty inodes
to the noop_backing_dev_info is not legal and will not result in
them being flushed, but we already catch this condition in
__mark_inode_dirty() when checking for a registered bdi.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-25 08:54:42 +02:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
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>
2010-03-30 22:02:32 +09:00
Christoph Hellwig
5fb324ad24 quota: move code from sync_quota_sb into vfs_quota_sync
Currenly sync_quota_sb does a lot of sync and truncate action that only
applies to "VFS" style quotas and is actively harmful for the sync
performance in XFS.  Move it into vfs_quota_sync and add a wait parameter
to ->quota_sync to tell if we need it or not.

My audit of the GFS2 code says it's also not needed given the way GFS2
implements quotas, but I'd be happy if this can get a detailed review.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2010-03-05 00:20:24 +01:00
Christoph Hellwig
7a0ad10c36 fold do_sync_file_range into sys_sync_file_range
We recently go rid of all callers of do_sync_file_range as they're better
served with vfs_fsync or the filemap_write_and_wait.  Now that
do_sync_file_range is down to a single caller fold it into it so that people
don't start using it again accidentally.  While at it also switch it from
using __filemap_fdatawrite_range(..., WB_SYNC_ALL) to the more clear
filemap_fdatawrite_range().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-17 11:03:25 -05:00
Christoph Hellwig
94004ed726 kill wait_on_page_writeback_range
All callers really want the more logical filemap_fdatawait_range interface,
so convert them to use it and merge wait_on_page_writeback_range into
filemap_fdatawait_range.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-12-10 15:02:50 +01:00
Christoph Hellwig
6b2f3d1f76 vfs: Implement proper O_SYNC semantics
While Linux provided an O_SYNC flag basically since day 1, it took until
Linux 2.4.0-test12pre2 to actually get it implemented for filesystems,
since that day we had generic_osync_around with only minor changes and the
great "For now, when the user asks for O_SYNC, we'll actually give
O_DSYNC" comment.  This patch intends to actually give us real O_SYNC
semantics in addition to the O_DSYNC semantics.  After Jan's O_SYNC
patches which are required before this patch it's actually surprisingly
simple, we just need to figure out when to set the datasync flag to
vfs_fsync_range and when not.

This patch renames the existing O_SYNC flag to O_DSYNC while keeping it's
numerical value to keep binary compatibility, and adds a new real O_SYNC
flag.  To guarantee backwards compatiblity it is defined as expanding to
both the O_DSYNC and the new additional binary flag (__O_SYNC) to make
sure we are backwards-compatible when compiled against the new headers.

This also means that all places that don't care about the differences can
just check O_DSYNC and get the right behaviour for O_SYNC, too - only
places that actuall care need to check __O_SYNC in addition.  Drivers and
network filesystems have been updated in a fail safe way to always do the
full sync magic if O_DSYNC is set.  The few places setting O_SYNC for
lower layers are kept that way for now to stay failsafe.

We enforce that O_DSYNC is set when __O_SYNC is set early in the open path
to make sure we always get these sane options.

Note that parisc really screwed up their headers as they already define a
O_DSYNC that has always been a no-op.  We try to repair it by using it for
the new O_DSYNC and redefinining O_SYNC to send both the traditional
O_SYNC numerical value _and_ the O_DSYNC one.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger@sun.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-12-10 15:02:50 +01:00
H Hartley Sweeten
1fe72eaa0f fs/buffer.c: clean up EXPORT* macros
According to Documentation/CodingStyle the EXPORT* macro should follow
immediately after the closing function brace line.

Also, mark_buffer_async_write_endio() and do_thaw_all() are not used
elsewhere so they should be marked as static.

In addition, file_fsync() is actually in fs/sync.c so move the EXPORT* to
that file.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 07:39:29 -07:00
Jens Axboe
32a88aa1b6 fs: Assign bdi in super_block
We do this automatically in get_sb_bdev() from the set_bdev_super()
callback. Filesystems that have their own private backing_dev_info
must assign that in ->fill_super().

Note that ->s_bdi assignment is required for proper writeback!

Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-16 15:18:51 +02:00
Christoph Hellwig
2daea67e96 fsync: wait for data writeout completion before calling ->fsync
Currenly vfs_fsync(_range) first calls filemap_fdatawrite to write out
the data, the calls into ->fsync to write out the metadata and then finally
calls filemap_fdatawait to wait for the data I/O to complete.  What sounds
like a clever micro-optimization actually is nast trap for many filesystems.

For many modern filesystems i_size or other inode information is only
updated on I/O completion and we need to wait for I/O to finish before
we can write out the metadata.  For old fashionen filesystems that
instanciate blocks during the actual write and also update the metadata
at that point it opens up a large window were we could expose uninitialized
blocks after a crash.  While a few filesystems that need it already wait
for the I/O to finish inside their ->fsync methods it is rather suboptimal
as it is done under the i_mutex and also always for the whole file instead
of just a part as we could do for O_SYNC handling.

Here is a small audit of all fsync instances in the tree:

 - spufs_mfc_fsync:
 - ps3flash_fsync:
 - vol_cdev_fsync:
 - printer_fsync:
 - fb_deferred_io_fsync:
 - bad_file_fsync:
 - simple_sync_file:

	don't care - filesystems/drivers do't use the page cache or are
	purely in-memory.

 - simple_fsync:
 - file_fsync:
 - affs_file_fsync:
 - fat_file_fsync:
 - jfs_fsync:
 - ubifs_fsync:
 - reiserfs_dir_fsync:
 - reiserfs_sync_file:

	never touch pagecache themselves.  We need to wait before if we do
	not want to expose stale data after an allocation.

 - afs_fsync:
 - fuse_fsync_common:

	do the waiting writeback itself in awkward ways, would benefit from
	proper semantics

 - block_fsync:

	Does a filemap_write_and_wait on the block device inode.  Because we
	now have f_mapping that is the same inode we call it on in vfs_fsync.
	So just removing it and letting the VFS do the work in one go would
	be an improvement.

 - btrfs_sync_file:
 - cifs_fsync:
 - xfs_file_fsync:

	need the wait first and currently do it themselves. would benefit from
	doing it outside i_mutex.

 - coda_fsync:
 - ecryptfs_fsync:
 - exofs_file_fsync:
 - shm_fsync:

	only passes the fsync through to the lower layer

 - ext3_sync_file:

	doesn't seem to care, comments are confusing.

 - ext4_sync_file:

	would need the wait to work correctly for delalloc mode with late
	i_size updates.  Otherwise the ext3 comment applies.

	currently implemens it's own writeback and wait in an odd way,
	could benefit from doing it properly.

 - gfs2_fsync:

	not needed for journaled data mode, but probably harmless there.
	Currently writes back data asynchronously itself.  Needs some
	major audit.

 - hostfs_fsync:

	just calls fsync/datasync on the host FD.  Without the wait before
	data might not even be inflight yet if we're unlucky.

 - hpfs_file_fsync:
 - ncp_fsync:

	no-ops.  Dangerous before and after.

 - jffs2_fsync:

	just calls jffs2_flush_wbuf_gc, not sure how this relates to data.

 - nfs_fsync_dir:

	just increments stats, claims all directory operations are synchronous

 - nfs_file_fsync:

	only writes out data???  Looks very odd.

 - nilfs_sync_file:

	looks like it expects all data done, but not sure from the code

 - ntfs_dir_fsync:
 - ntfs_file_fsync:

	appear to do their own data writeback.  Very convoluted code.

 - ocfs2_sync_file:

	does it's own data writeback, but no wait.  probably needs the wait.

 - smb_fsync:

	according to a comment expects all pages written already, probably needs
	the wait before.

This patch only changes vfs_fsync_range, removal of the wait in the methods
that have it is left to the filesystem maintainers.  Note that most
filesystems really do need an audit for their fsync methods given the
gems found in this very brief audit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-09-14 17:08:17 +02:00
Jan Kara
148f948ba8 vfs: Introduce new helpers for syncing after writing to O_SYNC file or IS_SYNC inode
Introduce new function for generic inode syncing (vfs_fsync_range) and use
it from fsync() path. Introduce also new helper for syncing after a sync
write (generic_write_sync) using the generic function.

Use these new helpers for syncing from generic VFS functions. This makes
O_SYNC writes to block devices acquire i_mutex for syncing. If we really
care about this, we can make block_fsync() drop the i_mutex and reacquire
it before it returns.

CC: Evgeniy Polyakov <zbr@ioremap.net>
CC: ocfs2-devel@oss.oracle.com
CC: Joel Becker <joel.becker@oracle.com>
CC: Felix Blyakher <felixb@sgi.com>
CC: xfs@oss.sgi.com
CC: Anton Altaparmakov <aia21@cantab.net>
CC: linux-ntfs-dev@lists.sourceforge.net
CC: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
CC: linux-ext4@vger.kernel.org
CC: tytso@mit.edu
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-09-14 17:08:15 +02:00
Jens Axboe
03ba3782e8 writeback: switch to per-bdi threads for flushing data
This gets rid of pdflush for bdi writeout and kupdated style cleaning.
pdflush writeout suffers from lack of locality and also requires more
threads to handle the same workload, since it has to work in a
non-blocking fashion against each queue. This also introduces lumpy
behaviour and potential request starvation, since pdflush can be starved
for queue access if others are accessing it. A sample ffsb workload that
does random writes to files is about 8% faster here on a simple SATA drive
during the benchmark phase. File layout also seems a LOT more smooth in
vmstat:

 r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id wa
 0  1      0 608848   2652 375372    0    0     0 71024  604    24  1 10 48 42
 0  1      0 549644   2712 433736    0    0     0 60692  505    27  1  8 48 44
 1  0      0 476928   2784 505192    0    0     4 29540  553    24  0  9 53 37
 0  1      0 457972   2808 524008    0    0     0 54876  331    16  0  4 38 58
 0  1      0 366128   2928 614284    0    0     4 92168  710    58  0 13 53 34
 0  1      0 295092   3000 684140    0    0     0 62924  572    23  0  9 53 37
 0  1      0 236592   3064 741704    0    0     4 58256  523    17  0  8 48 44
 0  1      0 165608   3132 811464    0    0     0 57460  560    21  0  8 54 38
 0  1      0 102952   3200 873164    0    0     4 74748  540    29  1 10 48 41
 0  1      0  48604   3252 926472    0    0     0 53248  469    29  0  7 47 45

where vanilla tends to fluctuate a lot in the creation phase:

 r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id wa
 1  1      0 678716   5792 303380    0    0     0 74064  565    50  1 11 52 36
 1  0      0 662488   5864 319396    0    0     4   352  302   329  0  2 47 51
 0  1      0 599312   5924 381468    0    0     0 78164  516    55  0  9 51 40
 0  1      0 519952   6008 459516    0    0     4 78156  622    56  1 11 52 37
 1  1      0 436640   6092 541632    0    0     0 82244  622    54  0 11 48 41
 0  1      0 436640   6092 541660    0    0     0     8  152    39  0  0 51 49
 0  1      0 332224   6200 644252    0    0     4 102800  728    46  1 13 49 36
 1  0      0 274492   6260 701056    0    0     4 12328  459    49  0  7 50 43
 0  1      0 211220   6324 763356    0    0     0 106940  515    37  1 10 51 39
 1  0      0 160412   6376 813468    0    0     0  8224  415    43  0  6 49 45
 1  1      0  85980   6452 886556    0    0     4 113516  575    39  1 11 54 34
 0  2      0  85968   6452 886620    0    0     0  1640  158   211  0  0 46 54

A 10 disk test with btrfs performs 26% faster with per-bdi flushing. A
SSD based writeback test on XFS performs over 20% better as well, with
the throughput being very stable around 1GB/sec, where pdflush only
manages 750MB/sec and fluctuates wildly while doing so. Random buffered
writes to many files behave a lot better as well, as does random mmap'ed
writes.

A separate thread is added to sync the super blocks. In the long term,
adding sync_supers_bdi() functionality could get rid of this thread again.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11 09:20:25 +02:00
Jens Axboe
d8a8559cd7 writeback: get rid of generic_sync_sb_inodes() export
This adds two new exported functions:

- writeback_inodes_sb(), which only attempts to writeback dirty inodes on
  this super_block, for WB_SYNC_NONE writeout.
- sync_inodes_sb(), which writes out all dirty inodes on this super_block
  and also waits for the IO to complete.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11 09:20:25 +02:00
Zhang, Yanmin
3beab0b424 sys_sync(): fix 16% performance regression in ffsb create_4k test
I run many ffsb test cases on JBODs (typically 13/12 disks).  Comparing
with kernel 2.6.30, 2.6.31-rc1 has about 16% regression with
ffsb_create_4k.  The sub test case creates files continuously for 10
minitues and every file is 1MB.

Bisect located below patch.

5cee5815d1 is first bad commit
commit 5cee5815d1
Author: Jan Kara <jack@suse.cz>
Date:   Mon Apr 27 16:43:51 2009 +0200

    vfs: Make sys_sync() use fsync_super() (version 4)

    It is unnecessarily fragile to have two places (fsync_super() and do_sync())
    doing data integrity sync of the filesystem. Alter __fsync_super() to
    accommodate needs of both callers and use it. So after this patch
    __fsync_super() is the only place where we gather all the calls needed to
    properly send all data on a filesystem to disk.

As a matter of fact, ffsb calls sys_sync in the end to make sure all data
is flushed to disks and the flushing is counted into the result.  vmstat
shows ffsb is blocked when syncing for a long time.  With 2.6.30, ffsb is
blocked for a short time.

I checked the patch and did experiments to recover the original methods.
Eventually, the root cause is the patch deletes the calling to
wakeup_pdflush when syncing, so only ffsb is blocked on disk I/O.
wakeup_pdflush could ask pdflush to write back pages with ffsb at the
same time.

[akpm@linux-foundation.org: restore comment too]
Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-06 13:57:03 -07:00
Christoph Hellwig
0c95ee190e remove the call to ->write_super in __sync_filesystem
Now that all filesystems provide ->sync_fs methods we can change
__sync_filesystem to only call ->sync_fs.

This gives us a clear separation between periodic writeouts which
are driven by ->write_super and data integrity syncs that go
through ->sync_fs. (modulo file_fsync which is also going away)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:17 -04:00
Christoph Hellwig
ebc1ac1645 ->write_super lock_super pushdown
Push down lock_super into ->write_super instances and remove it from the
caller.

Following filesystem don't need ->s_lock in ->write_super and are skipped:

 * bfs, nilfs2 - no other uses of s_lock and have internal locks in
	->write_super
 * ext2 - uses BKL in ext2_write_super and has internal calls without s_lock
 * reiserfs - no other uses of s_lock as has reiserfs_write_lock (BKL) in
 	->write_super
 * xfs - no other uses of s_lock and uses internal lock (buffer lock on
	superblock buffer) to serialize ->write_super.  Also xfs_fs_write_super
	is superflous and will go away in the next merge window

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:09 -04:00
Christoph Hellwig
5af7926ff3 enforce ->sync_fs is only called for rw superblock
Make sure a superblock really is writeable by checking MS_RDONLY
under s_umount.  sync_filesystems needed some re-arragement for
that, but all but one sync_filesystem caller had the correct locking
already so that we could add that check there.  cachefiles grew
s_umount locking.

I've also added a WARN_ON to sync_filesystem to assert this for
future callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:06 -04:00
Jan Kara
c3f8a40c1c quota: Introduce writeout_quota_sb() (version 4)
Introduce this function which just writes all the quota structures but
avoids all the syncing and cache pruning work to expose quota structures
to userspace. Use this function from __sync_filesystem when wait == 0.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:04 -04:00
Christoph Hellwig
850b201b08 quota: cleanup dquota sync functions (version 4)
Currently the VFS calls vfs_dq_sync to sync out disk quotas for a given
superblock.  This is a small wrapper around sync_dquots which for the
case of a non-NULL superblock is a small wrapper around quota_sync_sb.

Just make quota_sync_sb global (rename it to sync_quota_sb) and call it
directly.  Also call it directly for those cases in quota.c that have a
superblock and leave sync_dquots purely an iterator over sync_quota_sb and
remove it's superblock argument.

To make this nicer move the check for the lack of a quota_sync method
from the callers into sync_quota_sb.

[folded build fix from Alexander Beregalov <a.beregalov@gmail.com>]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:04 -04:00
Jan Kara
60b0680fa2 vfs: Rename fsync_super() to sync_filesystem() (version 4)
Rename the function so that it better describe what it really does. Also
remove the unnecessary include of buffer_head.h.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:04 -04:00
Jan Kara
c15c54f5f0 vfs: Move syncing code from super.c to sync.c (version 4)
Move sync_filesystems(), __fsync_super(), fsync_super() from
super.c to sync.c where it fits better.

[build fixes folded]

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:04 -04:00
Jan Kara
5cee5815d1 vfs: Make sys_sync() use fsync_super() (version 4)
It is unnecessarily fragile to have two places (fsync_super() and do_sync())
doing data integrity sync of the filesystem. Alter __fsync_super() to
accommodate needs of both callers and use it. So after this patch
__fsync_super() is the only place where we gather all the calls needed to
properly send all data on a filesystem to disk.

Nice bonus is that we get a complete livelock avoidance and write_supers()
is now only used for periodic writeback of superblocks.

sync_blockdevs() introduced a couple of patches ago is gone now.

[build fixes folded]

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:03 -04:00
Jan Kara
5a3e5cb8e0 vfs: Fix sys_sync() and fsync_super() reliability (version 4)
So far, do_sync() called:
  sync_inodes(0);
  sync_supers();
  sync_filesystems(0);
  sync_filesystems(1);
  sync_inodes(1);

This ordering makes it kind of hard for filesystems as sync_inodes(0) need not
submit all the IO (for example it skips inodes with I_SYNC set) so e.g. forcing
transaction to disk in ->sync_fs() is not really enough. Therefore sys_sync has
not been completely reliable on some filesystems (ext3, ext4, reiserfs, ocfs2
and others are hit by this) when racing e.g. with background writeback. A
similar problem hits also other filesystems (e.g. ext2) because of
write_supers() being called before the sync_inodes(1).

Change the ordering of calls in do_sync() - this requires a new function
sync_blockdevs() to preserve the property that block devices are always synced
after write_super() / sync_fs() call.

The same issue is fixed in __fsync_super() function used on umount /
remount read-only.

[AV: build fixes]

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:03 -04:00