Commit Graph

23508 Commits

Author SHA1 Message Date
Al Viro
963945bf93 fix jffs2 ACLs on big-endian with 16bit mode_t
casting int * to mode_t * is not a good thing - on a *lot* of big-endian
architectures mode_t happens to be smaller than int and there it breaks
quite spectaculary...

Fucked-up-by: commit cfc8dc6f6f
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-24 10:12:01 -04:00
Al Viro
1ec95bf34d 9p: close ACL leaks
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-24 10:10:18 -04:00
Al Viro
c0d960f038 ocfs2_init_acl(): fix a leak
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-24 10:10:09 -04:00
Tim Chen
423e0ab086 VFS : mount lock scalability for internal mounts
For a number of file systems that don't have a mount point (e.g. sockfs
and pipefs), they are not marked as long term. Therefore in
mntput_no_expire, all locks in vfs_mount lock are taken instead of just
local cpu's lock to aggregate reference counts when we release
reference to file objects.  In fact, only local lock need to have been
taken to update ref counts as these file systems are in no danger of
going away until we are ready to unregister them.

The attached patch marks file systems using kern_mount without
mount point as long term.  The contentions of vfs_mount lock
is now eliminated.  Before un-registering such file system,
kern_unmount should be called to remove the long term flag and
make the mount point ready to be freed.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-24 10:08:32 -04:00
Linus Torvalds
bbd9d6f7fb 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: (107 commits)
  vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp
  isofs: Remove global fs lock
  jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
  fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
  mm/truncate.c: fix build for CONFIG_BLOCK not enabled
  fs:update the NOTE of the file_operations structure
  Remove dead code in dget_parent()
  AFS: Fix silly characters in a comment
  switch d_add_ci() to d_splice_alias() in "found negative" case as well
  simplify gfs2_lookup()
  jfs_lookup(): don't bother with . or ..
  get rid of useless dget_parent() in btrfs rename() and link()
  get rid of useless dget_parent() in fs/btrfs/ioctl.c
  fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
  drivers: fix up various ->llseek() implementations
  fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
  Ext4: handle SEEK_HOLE/SEEK_DATA generically
  Btrfs: implement our own ->llseek
  fs: add SEEK_HOLE and SEEK_DATA flags
  reiserfs: make reiserfs default to barrier=flush
  ...

Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new
shrinker callout for the inode cache, that clashed with the xfs code to
start the periodic workers later.
2011-07-22 19:02:39 -07:00
Konstantin Khlebnikov
5a9a43646c vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp
Replace unclear (struct dentry *) to (struct file *) typecast with ERR_CAST() macro.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-22 19:42:13 -04:00
Jan Kara
d769b3c2ab isofs: Remove global fs lock
sbi->s_mutex isn't needed for isofs at all so we can just remove it. Generally,
since isofs is always mounted read-only, filesystem structure cannot change
under us.  So buffer_head contents stays constant after it's filled in. That
leaves us with possible changes of global data structures. Superblock changes
only during filesystem mount (even remount does not change it), inodes are only
filled in during reading from disk. So there are no changes of these structures
to bother about.

Arguments why sbi->s_mutex can be removed at each place:
isofs_readdir: Accesses sb, inode, filp, local variables => s_mutex not needed
isofs_lookup: Protected by directory's i_mutex. Accesses sb, inode, dentry,
  local variables => s_mutex not needed
rock_ridge_symlink_readpage: Protected by page lock. Accesses sb, inode,
  local variables => s_mutex not needed.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-22 19:42:12 -04:00
Al Viro
22ba747f66 jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
We don't generate IN_DELETE_SELF on victim of overwriting rename() if
it happens to be a directory.  Trivially fixed by doing to ->i_nlink
what we do ->pino_nlink a couple of lines later in jffs2_rename().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-22 19:42:11 -04:00
Al Viro
841590ce16 fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
On ramfs and other simple_rename() users IN_DELETE_SELF is not generated
for victim of overwriting rename() if it's is a directory.  Works on
most of the local filesystems and really trivial to fix...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-22 19:42:11 -04:00
Linus Torvalds
8209f53d79 Merge branch 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc
* 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc: (39 commits)
  ptrace: do_wait(traced_leader_killed_by_mt_exec) can block forever
  ptrace: fix ptrace_signal() && STOP_DEQUEUED interaction
  connector: add an event for monitoring process tracers
  ptrace: dont send SIGSTOP on auto-attach if PT_SEIZED
  ptrace: mv send-SIGSTOP from do_fork() to ptrace_init_task()
  ptrace_init_task: initialize child->jobctl explicitly
  has_stopped_jobs: s/task_is_stopped/SIGNAL_STOP_STOPPED/
  ptrace: make former thread ID available via PTRACE_GETEVENTMSG after PTRACE_EVENT_EXEC stop
  ptrace: wait_consider_task: s/same_thread_group/ptrace_reparented/
  ptrace: kill real_parent_is_ptracer() in in favor of ptrace_reparented()
  ptrace: ptrace_reparented() should check same_thread_group()
  redefine thread_group_leader() as exit_signal >= 0
  do not change dead_task->exit_signal
  kill task_detached()
  reparent_leader: check EXIT_DEAD instead of task_detached()
  make do_notify_parent() __must_check, update the callers
  __ptrace_detach: avoid task_detached(), check do_notify_parent()
  kill tracehook_notify_death()
  make do_notify_parent() return bool
  ptrace: s/tracehook_tracer_task()/ptrace_parent()/
  ...
2011-07-22 15:06:50 -07:00
Linus Torvalds
c1f792a5bf Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (49 commits)
  xfs: add size update tracepoint to IO completion
  xfs: convert AIL cursors to use struct list_head
  xfs: remove confusing ail cursor wrapper
  xfs: use a cursor for bulk AIL insertion
  xfs: failure mapping nfs fh to inode should return ESTALE
  xfs: Remove the second parameter to xfs_sb_count()
  xfs: remove the dead XFS_DABUF_DEBUG code
  xfs: remove leftovers of the old btree tracing code
  xfs: remove the dead QUOTADEBUG code
  xfs: remove the unused xfs_buf_delwri_sort function
  xfs: remove wrappers around b_iodone
  xfs: remove wrappers around b_fspriv
  xfs: add a proper transaction pointer to struct xfs_buf
  xfs: factor out xfs_da_grow_inode_int
  xfs: factor out xfs_dir2_leaf_find_stale
  xfs: cleanup struct xfs_dir2_free
  xfs: reshuffle dir2 headers
  xfs: start periodic workers later
  Revert "xfs: fix filesystsem freeze race in xfs_trans_alloc"
  xfs: remove variables that serve no purpose in xfs_alloc_ag_vextent_exact()
  ...
2011-07-22 13:16:33 -07:00
Linus Torvalds
6aaf4404ab Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
  dlm: don't limit active work items
  dlm: use workqueue for callbacks
  dlm: remove deadlock debug print
  dlm: improve rsb searches
  dlm: keep lkbs in idr
  dlm: fix kmalloc args
  dlm: don't do pointless NULL check, use kzalloc and fix order of arguments
  dlm: dump address of unknown node
  dlm: use vmalloc for hash tables
  dlm: show addresses in configfs
2011-07-22 13:16:07 -07:00
Linus Torvalds
ba1f9db908 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/hfsplus
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/hfsplus:
  hfsplus: ensure bio requests are not smaller than the hardware sectors
  hfsplus: Add additional range check to handle on-disk corruptions
  hfsplus: Add error propagation for hfsplus_ext_write_extent_locked
  hfsplus: add error checking for hfs_find_init()
  hfsplus: lift the 2TB size limit
  hfsplus: fix overflow in hfsplus_read_wrapper
  hfsplus: fix overflow in hfsplus_get_block
  hfsplus: assignments inside `if' condition clean-up
2011-07-22 13:12:17 -07:00
Linus Torvalds
49302baa64 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw:
  GFS2: combine duplicated block freeing routines
  GFS2: Add S_NOSEC support
  GFS2: Automatically adjust glock min hold time
  GFS2: Cache dir hash table in a contiguous buffer
2011-07-22 13:10:41 -07:00
Linus Torvalds
59a7ac1211 Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6
* 'linux-next' of git://git.infradead.org/ubifs-2.6: (32 commits)
  MAINTAINERS: change e-mail of Adrian Hunter
  UBIFS: fix master node recovery
  UBIFS: improve power cut emulation testing
  UBIFS: rename recovery testing variables
  UBIFS: remove custom list of superblocks
  UBIFS: stop re-defining UBI operations
  UBIFS: switch to I/O helpers
  UBIFS: switch to ubifs_leb_write
  UBIFS: switch to ubifs_leb_read
  UBIFS: introduce more I/O helpers
  UBIFS: always print stacktrace when switching to R/O mode
  UBIFS: remove unused and unneeded debugging function
  UBIFS: add global debugfs knobs
  UBIFS: introduce debugfs helpers
  UBIFS: re-arrange debugging code a bit
  UBIFS: be more informative in failure mode
  UBIFS: switch self-check knobs to debugfs
  UBIFS: lessen amount of debugging check types
  UBIFS: introduce helper functions for debugging checks and tests
  UBIFS: amend debugging inode size check function prototype
  ...
2011-07-22 13:09:35 -07:00
Seth Forshee
6596528e39 hfsplus: ensure bio requests are not smaller than the hardware sectors
Currently all bio requests are 512 bytes, which may fail for media
whose physical sector size is larger than this. Ensure these
requests are not smaller than the block device logical block size.

BugLink: http://bugs.launchpad.net/bugs/734883
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-07-22 16:37:44 +02:00
Naohiro Aota
aac4e4198e hfsplus: Add additional range check to handle on-disk corruptions
'recoff' is read from disk and used for an argument to memcpy, so if
the value read from disk is larger than the page size, it result to
"general protection fault". This patch add additional range check for
the value, so that disk fuzz won't cause such fault.

Signed-off-by: Naohiro Aota <naota@elisp.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-07-22 16:36:56 +02:00
Oleg Nesterov
eac1b5e57d ptrace: do_wait(traced_leader_killed_by_mt_exec) can block forever
Test-case:

	void *tfunc(void *arg)
	{
		execvp("true", NULL);
		return NULL;
	}

	int main(void)
	{
		int pid;

		if (fork()) {
			pthread_t t;

			kill(getpid(), SIGSTOP);

			pthread_create(&t, NULL, tfunc, NULL);

			for (;;)
				pause();
		}

		pid = getppid();
		assert(ptrace(PTRACE_ATTACH, pid, 0,0) == 0);

		while (wait(NULL) > 0)
			ptrace(PTRACE_CONT, pid, 0,0);

		return 0;
	}

It is racy, exit_notify() does __wake_up_parent() too. But in the
likely case it triggers the problem: de_thread() does release_task()
and the old leader goes away without the notification, the tracer
sleeps in do_wait() without children/tracees.

Change de_thread() to do __wake_up_parent(traced_leader->parent).
Since it is already EXIT_DEAD we can do this without ptrace_unlink(),
EXIT_DEAD threads do not exist from do_wait's pov.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
2011-07-22 15:10:49 +02:00
Linus Torvalds
2bafc7a275 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  CIFS: Fix wrong length in cifs_iovec_read
2011-07-21 14:28:01 -07:00
Linus Torvalds
b91da88fed vfs: drop conditional inode prefetch in __do_lookup_rcu
It seems to hurt performance in real life.  Yes, the inode will be used
later, but the conditional doesn't seem to predict all that well
(negative dentries are not uncommon) and it looks like the cost of
prefetching is simply higher than depending on the cache doing the right
thing.

As usual.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-21 11:01:42 -07:00
Jan Beulich
b307d4655a FS-Cache: Fix __fscache_uncache_all_inode_pages()'s outer loop
The compiler, at least for ix86 and m68k, validly warns that the
comparison:

	next <= (loff_t)-1

is always true (and it's always true also for x86-64 and probably all
other arches - as long as pgoff_t isn't wider than loff_t).  The
intention appears to be to avoid wrapping of "next", so rather than
eliminating the pointless comparison, fix the loop to indeed get exited
when "next" would otherwise wrap.

On m68k the following warning is observed:

  fs/fscache/page.c: In function '__fscache_uncache_all_inode_pages':
  fs/fscache/page.c:979: warning: comparison is always false due to limited range of data type

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Suresh Jayaraman <sjayaraman@suse.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-21 10:59:16 -07:00
Pavel Shilovsky
2cebaa58b7 CIFS: Fix wrong length in cifs_iovec_read
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-07-21 00:48:05 +00:00
Al Viro
86c98e8cdb Remove dead code in dget_parent()
->d_parent is never NULL...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:48:04 -04:00
David Howells
e4b9f00581 AFS: Fix silly characters in a comment
Fix silly characters in a comment in AFS code (some weird characters replaced
the word 'flag' some point way back).

Reported-by: viro@ZenIV.linux.org.uk
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:48:03 -04:00
Al Viro
4513d899c4 switch d_add_ci() to d_splice_alias() in "found negative" case as well
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:48:02 -04:00
Al Viro
6c673ab393 simplify gfs2_lookup()
d_splice_alias() will DTRT when given NULL or ERR_PTR

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:48:02 -04:00
Al Viro
79ac5a46c5 jfs_lookup(): don't bother with . or ..
they'll never be passed to ->lookup()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:48:01 -04:00
Al Viro
10d9f309d8 get rid of useless dget_parent() in btrfs rename() and link()
->d_parent is locked and stable there...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:48:00 -04:00
Al Viro
2fbe8c8ad1 get rid of useless dget_parent() in fs/btrfs/ioctl.c
both callers there have dentry->d_parent stabilized by the fact that
their caller had obtained dentry from lookup_one_len() and had not
dropped ->i_mutex on parent since then.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:48:00 -04:00
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
Josef Bacik
06222e491e fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
This converts everybody to handle SEEK_HOLE/SEEK_DATA properly.  In some cases
we just return -EINVAL, in others we do the normal generic thing, and in others
we're simply making sure that the properly due-dilligence is done.  For example
in NFS/CIFS we need to make sure the file size is update properly for the
SEEK_HOLE and SEEK_DATA case, but since it calls the generic llseek stuff itself
that is all we have to do.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:58 -04:00
Josef Bacik
c334b1138b Ext4: handle SEEK_HOLE/SEEK_DATA generically
Since Ext4 has its own lseek we need to make sure it handles
SEEK_HOLE/SEEK_DATA.  For now just do the same thing that is done in the generic
case, somebody else can come along and make it do fancy things later.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:57 -04:00
Josef Bacik
b26751575a Btrfs: implement our own ->llseek
In order to handle SEEK_HOLE/SEEK_DATA we need to implement our own llseek.
Basically for the normal SEEK_*'s we will just defer to the generic helper, and
for SEEK_HOLE/SEEK_DATA we will use our fiemap helper to figure out the nearest
hole or data.  Currently this helper doesn't check for delalloc bytes for
prealloc space, so for now treat prealloc as data until that is fixed.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:56 -04:00
Josef Bacik
982d816581 fs: add SEEK_HOLE and SEEK_DATA flags
This just gets us ready to support the SEEK_HOLE and SEEK_DATA flags.  Turns out
using fiemap in things like cp cause more problems than it solves, so lets try
and give userspace an interface that doesn't suck.  We need to match solaris
here, and the definitions are

*o* If /whence/ is SEEK_HOLE, the offset of the start of the
next hole greater than or equal to the supplied offset
is returned. The definition of a hole is provided near
the end of the DESCRIPTION.

*o* If /whence/ is SEEK_DATA, the file pointer is set to the
start of the next non-hole file region greater than or
equal to the supplied offset.

So in the generic case the entire file is data and there is a virtual hole at
the end.  That means we will just return i_size for SEEK_HOLE and will return
the same offset for SEEK_DATA.  This is how Solaris does it so we have to do it
the same way.

Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:56 -04:00
Christoph Hellwig
b4d5b10fb2 reiserfs: make reiserfs default to barrier=flush
Change the default reiserfs mount option to barrier=flush.  Based on a patch
from Jeff Mahoney in the SuSE tree.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:55 -04:00
Christoph Hellwig
00eacd66cd ext3: make ext3 mount default to barrier=1
This patch turns on barriers by default for ext3.  mount -o barrier=0
will turn them off.  Based on a patch from Chris Mason in the SuSE tree.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Jeff Mahoney <jeffm@suse.com>
Acked-by: Ted Ts'o <tytso@mit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:54 -04:00
Al Viro
b85fd6bdc9 don't open-code parent_ino() in assorted ->readdir()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:54 -04:00
Al Viro
2def9e4ec7 minix_getattr(): don't bother with ->d_parent
we can find superblock easier, TYVM...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:53 -04:00
Al Viro
ee60498f3e coda_venus_readdir(): use offsetof()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:52 -04:00
Kay Sievers
f15146380d fs: seq_file - add event counter to simplify poll() support
Moving the event counter into the dynamically allocated 'struc seq_file'
allows poll() support without the need to allocate its own tracking
structure.

All current users are switched over to use the new counter.

Requested-by: Andrew Morton akpm@linux-foundation.org
Acked-by: NeilBrown <neilb@suse.de>
Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:50 -04:00
Christoph Hellwig
72c5052ddc fs: move inode_dio_done to the end_io handler
For filesystems that delay their end_io processing we should keep our
i_dio_count until the the processing is done.  Enable this by moving
the inode_dio_done call to the end_io handler if one exist.  Note that
the actual move to the workqueue for ext4 and XFS is not done in
this patch yet, but left to the filesystem maintainers.  At least
for XFS it's not needed yet either as XFS has an internal equivalent
to i_dio_count.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:50 -04:00
Christoph Hellwig
aacfc19c62 fs: simplify the blockdev_direct_IO prototype
Simple filesystems always pass inode->i_sb_bdev as the block device
argument, and never need a end_io handler.  Let's simply things for
them and for my grepping activity by dropping these arguments.  The
only thing not falling into that scheme is ext4, which passes and
end_io handler without needing special flags (yet), but given how
messy the direct I/O code there is use of __blockdev_direct_IO
in one instead of two out of three cases isn't going to make a large
difference anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:49 -04:00
Christoph Hellwig
df2d6f2658 fs: always maintain i_dio_count
Maintain i_dio_count for all filesystems, not just those using DIO_LOCKING.
This these filesystems to also protect truncate against direct I/O requests
by using common code.  Right now the only non-DIO_LOCKING filesystem that
appears to do so is XFS, which uses an opencoded variant of the i_dio_count
scheme.

Behaviour doesn't change for filesystems never calling inode_dio_wait.
For ext4 behaviour changes when using the dioread_nonlock option, which
previously was missing any protection between truncate and direct I/O reads.
For ocfs2 that handcrafted i_dio_count manipulations are replaced with
the common code now enable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:48 -04:00
Christoph Hellwig
562c72aa57 fs: move inode_dio_wait calls into ->setattr
Let filesystems handle waiting for direct I/O requests themselves instead
of doing it beforehand.  This means filesystem-specific locks to prevent
new dio referenes from appearing can be held.  This is important to allow
generalizing i_dio_count to non-DIO_LOCKING filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:47 -04:00
Christoph Hellwig
bd5fe6c5eb fs: kill i_alloc_sem
i_alloc_sem is a rather special rw_semaphore.  It's the last one that may
be released by a non-owner, and it's write side is always mirrored by
real exclusion.  It's intended use it to wait for all pending direct I/O
requests to finish before starting a truncate.

Replace it with a hand-grown construct:

 - exclusion for truncates is already guaranteed by i_mutex, so it can
   simply fall way
 - the reader side is replaced by an i_dio_count member in struct inode
   that counts the number of pending direct I/O requests.  Truncate can't
   proceed as long as it's non-zero
 - when i_dio_count reaches non-zero we wake up a pending truncate using
   wake_up_bit on a new bit in i_flags
 - new references to i_dio_count can't appear while we are waiting for
   it to read zero because the direct I/O count always needs i_mutex
   (or an equivalent like XFS's i_iolock) for starting a new operation.

This scheme is much simpler, and saves the space of a spinlock_t and a
struct list_head in struct inode (typically 160 bits on a non-debug 64-bit
system).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:46 -04:00
Christoph Hellwig
f9b5570d7f fs: simplify handling of zero sized reads in __blockdev_direct_IO
Reject zero sized reads as soon as we know our I/O length, and don't
borther with locks or allocations that might have to be cleaned up
otherwise.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:45 -04:00
Jan Kara
9ea7df534e ext4: Rewrite ext4_page_mkwrite() to use generic helpers
Rewrite ext4_page_mkwrite() to use __block_page_mkwrite() helper. This
removes the need of using i_alloc_sem to avoid races with truncate which
seems to be the wrong locking order according to lock ordering documented in
mm/rmap.c. Also calling ext4_da_write_begin() as used by the old code seems to
be problematic because we can decide to flush delay-allocated blocks which
will acquire s_umount semaphore - again creating unpleasant lock dependency
if not directly a deadlock.

Also add a check for frozen filesystem so that we don't busyloop in page fault
when the filesystem is frozen.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:45 -04:00
Christoph Hellwig
5826869158 fat: remove i_alloc_sem abuse
Add a new rw_semaphore to protect bmap against truncate.  Previous
i_alloc_sem was abused for this, but it's going away in this series.

Note that we can't simply use i_mutex, given that the swapon code
calls ->bmap under it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:44 -04:00
Tobias Klauser
8c5dc70aae VFS: Fixup kerneldoc for generic_permission()
The flags parameter went away in
d749519b444db985e40b897f73ce1898b11f997e

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:43 -04:00
Dave Chinner
8daaa83145 xfs: make use of new shrinker callout for the inode cache
Convert the inode reclaim shrinker to use the new per-sb shrinker
operations. This allows much bigger reclaim batches to be used, and
allows the XFS inode cache to be shrunk in proportion with the VFS
dentry and inode caches. This avoids the problem of the VFS caches
being shrunk significantly before the XFS inode cache is shrunk
resulting in imbalances in the caches during reclaim.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:42 -04:00