linux-stable.git/include/linux/fs.h, branch linux-2.6.24.y

exportfs: make struct export_operations const

2007-10-22T15:13:21+00:00

Now that nfsd has stopped writing to the find_exported_dentry member we an
mark the export_operations const

Signed-off-by: Christoph Hellwig 
Cc: Neil Brown 
Cc: "J. Bruce Fields" 
Cc: 
Cc: Dave Kleikamp 
Cc: Anton Altaparmakov 
Cc: David Chinner 
Cc: Timothy Shimmin 
Cc: OGAWA Hirofumi 
Cc: Hugh Dickins 
Cc: Chris Mason 
Cc: Jeff Mahoney 
Cc: "Vladimir V. Saveliev" 
Cc: Steven Whitehouse 
Cc: Mark Fasheh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] new helpers - collect_mounts() and release_collected_mounts()

2007-10-21T06:37:25+00:00

Get a snapshot of a subtree, creating private clones of vfsmounts
for all its components and release such snapshot resp.

Signed-off-by: Al Viro

fix do_sys_open() prototype

2007-10-20T01:16:18+00:00

Fix an argument name in do_sys_open()'s prototype.

Signed-off-by: Jason Uhlenkott 
Signed-off-by: Adrian Bunk

pid namespaces: introduce MS_KERNMOUNT flag

2007-10-19T18:53:38+00:00

This flag tells the .get_sb callback that this is a kern_mount() call so that
it can trust *data pointer to be valid in-kernel one.  If this flag is passed
from the user process, it is cleared since the *data pointer is not a valid
kernel object.

Running a few steps forward - this will be needed for proc to create the
superblock and store a valid pid namespace on it during the namespace
creation.  The reason, why the namespace cannot live without proc mount is
described in the appropriate patch.

Signed-off-by: Pavel Emelyanov 
Cc: Oleg Nesterov 
Cc: Sukadev Bhattiprolu 
Cc: Paul Menage 
Cc: "Eric W. Biederman" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

put declaration of put_filesystem() in fs.h

2007-10-19T18:53:33+00:00

Declarations go into headers.

Signed-off-by: Miklos Szeredi 
Cc: Ram Pai 
Acked-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

VFS: allow filesystems to implement atomic open+truncate

2007-10-18T21:37:30+00:00

Add a new attribute flag ATTR_OPEN, with the meaning: "truncation was
initiated by open() due to the O_TRUNC flag".

This way filesystems wanting to implement truncation within their ->open()
method can ignore such truncate requests.

This is a quick & dirty hack, but it comes for free.

Signed-off-by: Miklos Szeredi 
Cc: Christoph Hellwig 
Cc: Al Viro 
Cc: Andreas Dilger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Implement file posix capabilities

2007-10-17T15:43:07+00:00

Implement file posix capabilities.  This allows programs to be given a
subset of root's powers regardless of who runs them, without having to use
setuid and giving the binary all of root's powers.

This version works with Kaigai Kohei's userspace tools, found at
http://www.kaigai.gr.jp/index.php.  For more information on how to use this
patch, Chris Friedhoff has posted a nice page at
http://www.friedhoff.org/fscaps.html.

Changelog:
	Nov 27:
	Incorporate fixes from Andrew Morton
	(security-introduce-file-caps-tweaks and
	security-introduce-file-caps-warning-fix)
	Fix Kconfig dependency.
	Fix change signaling behavior when file caps are not compiled in.

	Nov 13:
	Integrate comments from Alexey: Remove CONFIG_ ifdef from
	capability.h, and use %zd for printing a size_t.

	Nov 13:
	Fix endianness warnings by sparse as suggested by Alexey
	Dobriyan.

	Nov 09:
	Address warnings of unused variables at cap_bprm_set_security
	when file capabilities are disabled, and simultaneously clean
	up the code a little, by pulling the new code into a helper
	function.

	Nov 08:
	For pointers to required userspace tools and how to use
	them, see http://www.friedhoff.org/fscaps.html.

	Nov 07:
	Fix the calculation of the highest bit checked in
	check_cap_sanity().

	Nov 07:
	Allow file caps to be enabled without CONFIG_SECURITY, since
	capabilities are the default.
	Hook cap_task_setscheduler when !CONFIG_SECURITY.
	Move capable(TASK_KILL) to end of cap_task_kill to reduce
	audit messages.

	Nov 05:
	Add secondary calls in selinux/hooks.c to task_setioprio and
	task_setscheduler so that selinux and capabilities with file
	cap support can be stacked.

	Sep 05:
	As Seth Arnold points out, uid checks are out of place
	for capability code.

	Sep 01:
	Define task_setscheduler, task_setioprio, cap_task_kill, and
	task_setnice to make sure a user cannot affect a process in which
	they called a program with some fscaps.

	One remaining question is the note under task_setscheduler: are we
	ok with CAP_SYS_NICE being sufficient to confine a process to a
	cpuset?

	It is a semantic change, as without fsccaps, attach_task doesn't
	allow CAP_SYS_NICE to override the uid equivalence check.  But since
	it uses security_task_setscheduler, which elsewhere is used where
	CAP_SYS_NICE can be used to override the uid equivalence check,
	fixing it might be tough.

	     task_setscheduler
		 note: this also controls cpuset:attach_task.  Are we ok with
		     CAP_SYS_NICE being used to confine to a cpuset?
	     task_setioprio
	     task_setnice
		 sys_setpriority uses this (through set_one_prio) for another
		 process.  Need same checks as setrlimit

	Aug 21:
	Updated secureexec implementation to reflect the fact that
	euid and uid might be the same and nonzero, but the process
	might still have elevated caps.

	Aug 15:
	Handle endianness of xattrs.
	Enforce capability version match between kernel and disk.
	Enforce that no bits beyond the known max capability are
	set, else return -EPERM.
	With this extra processing, it may be worth reconsidering
	doing all the work at bprm_set_security rather than
	d_instantiate.

	Aug 10:
	Always call getxattr at bprm_set_security, rather than
	caching it at d_instantiate.

[morgan@kernel.org: file-caps clean up for linux/capability.h]
[bunk@kernel.org: unexport cap_inode_killpriv]
Signed-off-by: Serge E. Hallyn 
Cc: Stephen Smalley 
Cc: James Morris 
Cc: Chris Wright 
Cc: Andrew Morgan 
Signed-off-by: Andrew Morgan 
Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

introduce I_SYNC

2007-10-17T15:43:02+00:00

I_LOCK was used for several unrelated purposes, which caused deadlock
situations in certain filesystems as a side effect.  One of the purposes
now uses the new I_SYNC bit.

Also document the various bits and change their order from historical to
logical.

[bunk@stusta.de: make fs/inode.c:wake_up_inode() static]
Signed-off-by: Joern Engel 
Cc: Dave Kleikamp 
Cc: David Chinner 
Cc: Anton Altaparmakov 
Cc: Al Viro 
Cc: Christoph Hellwig 
Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

writeback: fix ntfs with sb_has_dirty_inodes()

2007-10-17T15:43:02+00:00

NTFS's if-condition on dirty inodes is not complete.  Fix it with
sb_has_dirty_inodes().

Cc: Anton Altaparmakov 
Cc: Ken Chen 
Signed-off-by: Fengguang Wu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

writeback: fix periodic superblock dirty inode flushing

2007-10-17T15:43:02+00:00

Current -mm tree has bucketful of bug fixes in periodic writeback path.
However, we still hit a glitch where dirty pages on a given inode aren't
completely flushed to the disk, and system will accumulate large amount of
dirty pages beyond what dirty_expire_interval is designed for.

The problem is __sync_single_inode() will move an inode to sb->s_dirty list
even when there are more pending dirty pages on that inode.  If there is
another inode with a small number of dirty pages, we hit a case where the loop
iteration in wb_kupdate() terminates prematurely because wbc.nr_to_write > 0.
Thus leaving the inode that has large amount of dirty pages behind and it has
to wait for another dirty_writeback_interval before we flush it again.  We
effectively only write out MAX_WRITEBACK_PAGES every dirty_writeback_interval.
If the rate of dirtying is sufficiently high, the system will start
accumulate a large number of dirty pages.

So fix it by having another sb->s_more_io list on which to park the inode
while we iterate through sb->s_io and to allow each dirty inode which resides
on that sb to have an equal chance of flushing some amount of dirty pages.

Signed-off-by: Ken Chen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds