linux.git/fs/file_table.c, branch v3.13

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2013-11-13T06:34:18+00:00

Pull vfs updates from Al Viro:
 "All kinds of stuff this time around; some more notable parts:

   - RCU'd vfsmounts handling
   - new primitives for coredump handling
   - files_lock is gone
   - Bruce's delegations handling series
   - exportfs fixes

  plus misc stuff all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits)
  ecryptfs: ->f_op is never NULL
  locks: break delegations on any attribute modification
  locks: break delegations on link
  locks: break delegations on rename
  locks: helper functions for delegation breaking
  locks: break delegations on unlink
  namei: minor vfs_unlink cleanup
  locks: implement delegations
  locks: introduce new FL_DELEG lock flag
  vfs: take i_mutex on renamed file
  vfs: rename I_MUTEX_QUOTA now that it's not used for quotas
  vfs: don't use PARENT/CHILD lock classes for non-directories
  vfs: pull ext4's double-i_mutex-locking into common code
  exportfs: fix quadratic behavior in filehandle lookup
  exportfs: better variable name
  exportfs: move most of reconnect_path to helper function
  exportfs: eliminate unused "noprogress" counter
  exportfs: stop retrying once we race with rename/remove
  exportfs: clear DISCONNECTED on all parents sooner
  exportfs: more detailed comment for path_reconnect
  ...

get rid of s_files and files_lock

2013-11-09T05:16:20+00:00

The only thing we need it for is alt-sysrq-r (emergency remount r/o)
and these days we can do just as well without going through the
list of files.

Signed-off-by: Al Viro

file->f_op is never NULL...

2013-10-25T03:34:54+00:00

Signed-off-by: Al Viro

nfsd regression since delayed fput()

2013-10-20T12:44:39+00:00

Background: nfsd v[23] had throughput regression since delayed fput
went in; every read or write ends up doing fput() and we get a pair
of extra context switches out of that (plus quite a bit of work
in queue_work itselfi, apparently).  Use of schedule_delayed_work()
gives it a chance to accumulate a bit before we do __fput() on all
of them.  I'm not too happy about that solution, but... on at least
one real-world setup it reverts about 10% throughput loss we got from
switch to delayed fput.

Signed-off-by: Al Viro

fs/file_table.c:fput(): make comment more truthful

2013-09-11T22:59:01+00:00

Cc: "Eric W. Biederman" 
Cc: Andrey Vagin 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

only regular files with FMODE_WRITE need to be on s_files

2013-09-04T02:50:28+00:00

Signed-off-by: Al Viro

fput: turn "list_head delayed_fput_list" into llist_head

2013-07-13T09:29:10+00:00

fput() and delayed_fput() can use llist and avoid the locking.

This is unlikely path, it is not that this change can improve
the performance, but this way the code looks simpler.

Signed-off-by: Oleg Nesterov 
Suggested-by: Andrew Morton 
Cc: Al Viro 
Cc: Andrey Vagin 
Cc: "Eric W. Biederman" 
Cc: David Howells 
Cc: Huang Ying 
Cc: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Al Viro

fs/file_table.c:fput(): add comment

2013-07-13T09:27:42+00:00

A missed update to "fput: task_work_add() can fail if the caller has
passed exit_task_work()".

Cc: "Eric W. Biederman" 
Cc: Al Viro 
Cc: Andrey Vagin 
Cc: David Howells 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Al Viro

Replace a bunch of file->dentry->d_inode refs with file_inode()

2013-06-29T08:57:13+00:00

Replace a bunch of file->dentry->d_inode refs with file_inode().

In __fput(), use file->f_inode instead so as not to be affected by any tricks
that file_inode() might grow.

Signed-off-by: David Howells 
Signed-off-by: Al Viro

fput: task_work_add() can fail if the caller has passed exit_task_work()

2013-06-15T01:39:08+00:00

fput() assumes that it can't be called after exit_task_work() but
this is not true, for example free_ipc_ns()->shm_destroy() can do
this. In this case fput() silently leaks the file.

Change it to fallback to delayed_fput_work if task_work_add() fails.
The patch looks complicated but it is not, it changes the code from

	if (PF_KTHREAD) {
		schedule_work(...);
		return;
	}
	task_work_add(...)

to
	if (!PF_KTHREAD) {
		if (!task_work_add(...))
			return;
		/* fallback */
	}
	schedule_work(...);

As for shm_destroy() in particular, we could make another fix but I
think this change makes sense anyway. There could be another similar
user, it is not safe to assume that task_work_add() can't fail.

Reported-by: Andrey Vagin 
Signed-off-by: Oleg Nesterov 
Signed-off-by: Al Viro