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* [PATCH 0/4] IMA: making i_readcount a first class inode citizen
@ 2010-10-28 22:02 Mimi Zohar
  2010-10-28 22:02 ` [PATCH 1/4] IMA: define readcount functions Mimi Zohar
                   ` (5 more replies)
  0 siblings, 6 replies; 25+ messages in thread
From: Mimi Zohar @ 2010-10-28 22:02 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mimi Zohar, linux-security-module, linux-fsdevel, hch, warthog9,
	david, jmorris, kyle, hpa, akpm, torvalds, mingo, eparis, viro,
	Matthew Wilcox

On Mon, 2010-10-25 at 14:41 -0400, Eric Paris wrote:

<snip>

> I believe that IBM is going to look into making i_readcount a first
> class citizen which can be used by both IMA and generic_setlease().
> Then people could say IMA had 0 per inode overhead   :)

This patchset separates the incrementing/decrementing of the i_readcount,
in the VFS layer, from other IMA functionality, by replacing the current
ima_counts_get() call with iget_readcount(). Its unclear whether this
call to increment i_readcount should be made earlier. 

The patch ordering is a bit redundant in order to leave removing the ifdef
around i_readcount until the last patch. The first three patches: defines 
iget/iput_readcount(), moves the IMA functionality in ima_counts_get() to
ima_file_check(), and removes the IMA imbalance code, simplifying IMA. The
last patch moves iget/iput_readcount() to the fs directory and removes the
ifdef around i_readcount, making i_readcount into a "first class inode citizen".

The generic_setlease code could then take advantage of i_readcount, assuming
it can take the spin_lock, by doing something like:

-		if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
+
+		spin_lock(&inode->i_lock);
+		if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0)){
+			spin_unlock(&inode->i_lock);
 			goto out;
-		if ((arg == F_WRLCK)
-		    && ((atomic_read(&dentry->d_count) > 1)
-			|| (atomic_read(&inode->i_count) > 1)))
+		}
+		if ((arg == F_WRLCK) && (inode->i_readcount > 1)) {
+			spin_unlock(&inode->i_lock);
 			goto out;
+		}
+		spin_unlock(&inode->i_lock);
 	}
 
Mimi

Mimi Zohar (4):
  IMA: define readcount functions
  IMA: maintain i_readcount in the VFS layer
  IMA: remove IMA imbalance checking
  IMA: making i_readcount a first class inode citizen

 fs/file_table.c                   |   23 +++++++-
 fs/inode.c                        |    3 +
 fs/open.c                         |    3 +-
 include/linux/fs.h                |    4 +-
 include/linux/ima.h               |    6 --
 security/integrity/ima/ima_iint.c |    5 --
 security/integrity/ima/ima_main.c |  125 ++++--------------------------------
 7 files changed, 43 insertions(+), 126 deletions(-)

-- 
1.7.2.2


^ permalink raw reply	[flat|nested] 25+ messages in thread
* [PATCH 0/4] IMA: making i_readcount a first class inode citizen
@ 2011-02-14 20:29 Mimi Zohar
  2011-02-16 23:08 ` Mimi Zohar
  0 siblings, 1 reply; 25+ messages in thread
From: Mimi Zohar @ 2011-02-14 20:29 UTC (permalink / raw)
  To: linux-kernel
  Cc: Mimi Zohar, linux-security-module, linux-fsdevel, James Morris,
	torvalds, eparis, viro, Dave Chinner, J. Bruce Fields,
	David Safford

This is a repost of patches 1 - 4 of the ima-i_readcount patch set rebased
against security-testing/#next, as requested a while ago.  The patches are
also available from:
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/ima-2.6.git/#next

This patchset separates the incrementing/decrementing of the i_readcount,
in the VFS layer, from other IMA functionality, by replacing the current
ima_counts_get() call with i_readcount_inc(). Its unclear whether this
call to increment i_readcount should be made earlier, like i_writecount.
Currently the call is situated immediately after the switch from put_filp()
to fput() for cleanup.

Mimi

Mimi Zohar (4):
  IMA: convert i_readcount to atomic
  IMA: define readcount functions
  IMA: maintain i_readcount in the VFS layer
  IMA: remove IMA imbalance checking

 fs/file_table.c                   |    5 +-
 fs/open.c                         |    3 +-
 include/linux/fs.h                |   23 ++++++-
 include/linux/ima.h               |    6 --
 security/integrity/ima/ima_iint.c |    5 --
 security/integrity/ima/ima_main.c |  130 ++++---------------------------------
 6 files changed, 40 insertions(+), 132 deletions(-)

-- 
1.7.3.4


^ permalink raw reply	[flat|nested] 25+ messages in thread
end of thread, other threads:[~2011-02-17  1:46 UTC | newest]

Thread overview: 25+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-10-28 22:02 [PATCH 0/4] IMA: making i_readcount a first class inode citizen Mimi Zohar
2010-10-28 22:02 ` [PATCH 1/4] IMA: define readcount functions Mimi Zohar
2010-10-28 22:02 ` [PATCH 2/4] IMA: maintain i_readcount in the VFS layer Mimi Zohar
2010-10-29 14:13   ` Valdis.Kletnieks
2010-10-29 15:15     ` Valdis.Kletnieks
2010-10-28 22:02 ` [PATCH 3/4] IMA: remove IMA imbalance checking Mimi Zohar
2010-10-28 22:02 ` [PATCH 4/4] IMA: making i_readcount a first class inode citizen Mimi Zohar
2010-10-28 22:24 ` [PATCH 0/4] " Dave Chinner
2010-10-28 22:29   ` Linus Torvalds
2010-10-28 22:38     ` Mimi Zohar
2010-10-28 22:46       ` Linus Torvalds
2010-10-28 23:25         ` Al Viro
2010-10-28 22:45     ` Eric Paris
2010-10-29  0:30       ` Mimi Zohar
2010-11-06 10:44       ` Pavel Machek
2010-11-05  1:12 ` J. Bruce Fields
2010-11-05 11:08   ` Mimi Zohar
2010-11-05 16:28     ` J. Bruce Fields
2010-11-05 17:38       ` Mimi Zohar
2010-11-05 19:08         ` J. Bruce Fields
2010-11-05 20:58           ` J. Bruce Fields
2010-11-07  0:03           ` Mimi Zohar
  -- strict thread matches above, loose matches on Subject: below --
2011-02-14 20:29 Mimi Zohar
2011-02-16 23:08 ` Mimi Zohar
2011-02-17  1:46   ` James Morris

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