linux-toradex.git/include/linux/fs.h, branch v2.6.25.17

block: Properly notify block layer of sync writes

2008-07-24T16:14:03+00:00

commit 18ce3751ccd488c78d3827e9f6bf54e6322676fb upstream

fsync_buffers_list() and sync_dirty_buffer() both issue async writes and
then immediately wait on them. Conceptually, that makes them sync writes
and we should treat them as such so that the IO schedulers can handle
them appropriately.

This patch fixes a write starvation issue that Lin Ming reported, where
xx is stuck for more than 2 minutes because of a large number of
synchronous IO in the system:

INFO: task kjournald:20558 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
kjournald     D ffff810010820978  6712 20558      2
ffff81022ddb1d10 0000000000000046 ffff81022e7baa10 ffffffff803ba6f2
ffff81022ecd0000 ffff8101e6dc9160 ffff81022ecd0348 000000008048b6cb
0000000000000086 ffff81022c4e8d30 0000000000000000 ffffffff80247537
Call Trace:
[] kobject_get+0x12/0x17
[] getnstimeofday+0x2f/0x83
[] sync_buffer+0x0/0x3f
[] io_schedule+0x5d/0x9f
[] sync_buffer+0x3b/0x3f
[] __wait_on_bit+0x40/0x6f
[] sync_buffer+0x0/0x3f
[] out_of_line_wait_on_bit+0x6c/0x78
[] wake_bit_function+0x0/0x23
[] sync_dirty_buffer+0x98/0xcb
[] journal_commit_transaction+0x97d/0xcb6
[] lock_timer_base+0x26/0x4b
[] kjournald+0xc1/0x1fb
[] autoremove_wake_function+0x0/0x2e
[] kjournald+0x0/0x1fb
[] kthread+0x47/0x74
[] schedule_tail+0x28/0x5d
[] child_rip+0xa/0x12
[] kthread+0x0/0x74
[] child_rip+0x0/0x12

Lin Ming confirms that this patch fixes the issue. I've run tests with
it for the past week and no ill effects have been observed, so I'm
proposing it for inclusion into 2.6.26.

Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

make struct def_blk_aops static

2008-02-19T09:04:00+00:00

This patch makes the needlessly global struct def_blk_aops static.

Signed-off-by: Adrian Bunk 
Signed-off-by: Jens Axboe

vfs: add explanation of I_DIRTY_DATASYNC bit

2008-02-15T04:58:06+00:00

Add explanation of I_DIRTY_DATASYNC bit.

Signed-off-by: Jan Kara 
Cc: Joern Engel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs/char_dev.c: chrdev_open marked static and removed from fs.h

2008-02-08T17:22:42+00:00

There is an outdated comment in serial_core.c also fixed.

Signed-off-by: Denis Cheng 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mount options: add generic_show_options()

2008-02-08T17:22:39+00:00

Add a new s_options field to struct super_block.  Filesystems can save
mount options passed to them in mount or remount.  It is automatically
freed when the superblock is destroyed.

A new helper function, generic_show_options() is introduced, which uses
this field to display the mount options in /proc/mounts.

Another helper function, save_mount_options() may be used by
filesystems to save the options in the super block.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kill do_generic_mapping_read

2008-02-08T17:22:39+00:00

do_generic_mapping_read was used by gfs2 for internals reads, but this use
of the interface was rather suboptimal (as was the whole interface) and has
been replaced by an internal helper now.  This patch kills
do_generic_mapping_read and surrounding damage in preparation of additional
cleanups for the buffered read path.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

libfs: rename simple_attr_close to simple_attr_release

2008-02-08T17:22:34+00:00

simple_attr_close implementes ->release so it should be named accordingly.

Signed-off-by: Christoph Hellwig 
Cc: 
Cc: Arnd Bergmann 
Cc: Greg KH 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

libfs: allow error return from simple attributes

2008-02-08T17:22:34+00:00

Sometimes simple attributes might need to return an error, e.g. for
acquiring a mutex interruptibly.  In fact we have that situation in
spufs already which is the original user of the simple attributes.  This
patch merged the temporarily forked attributes in spufs back into the
main ones and allows to return errors.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Christoph Hellwig 
Cc: 
Cc: Arnd Bergmann 
Cc: Greg KH 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

iget: remove iget() and the read_inode() super op as being obsolete

2008-02-07T16:42:29+00:00

Remove the old iget() call and the read_inode() superblock operation it uses
as these are really obsolete, and the use of read_inode() does not produce
proper error handling (no distinction between ENOMEM and EIO when marking an
inode bad).

Furthermore, this removes the temptation to use iget() to find an inode by
number in a filesystem from code outside that filesystem.

iget_locked() should be used instead.  A new function is added in an earlier
patch (iget_failed) that is to be called to mark an inode as bad, unlock it
and release it should the get routine fail.  Mark iget() and read_inode() as
being obsolete and remove references to them from the documentation.

Typically a filesystem will be modified such that the read_inode function
becomes an internal iget function, for example the following:

	void thingyfs_read_inode(struct inode *inode)
	{
		...
	}

would be changed into something like:

	struct inode *thingyfs_iget(struct super_block *sp, unsigned long ino)
	{
		struct inode *inode;
		int ret;

		inode = iget_locked(sb, ino);
		if (!inode)
			return ERR_PTR(-ENOMEM);
		if (!(inode->i_state & I_NEW))
			return inode;

		...
		unlock_new_inode(inode);
		return inode;
	error:
		iget_failed(inode);
		return ERR_PTR(ret);
	}

and then thingyfs_iget() would be called rather than iget(), for example:

	ret = -EINVAL;
	inode = iget(sb, ino);
	if (!inode || is_bad_inode(inode))
		goto error;

becomes:

	inode = thingyfs_iget(sb, ino);
	if (IS_ERR(inode)) {
		ret = PTR_ERR(inode);
		goto error;
	}

Note that is_bad_inode() does not need to be called.  The error returned by
thingyfs_iget() should render it unnecessary.

Signed-off-by: David Howells 
Acked-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

iget: introduce a function to register iget failure

2008-02-07T16:42:26+00:00

Introduce a function to register failure in an inode construction path.  This
includes marking the inode under construction as bad, unlocking it and
releasing it.

Signed-off-by: David Howells 
Acked-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds