This is a note to let you know that I've just added the patch titled
GFS2: Don't call file_accessed() with a shared glock
to the 3.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
gfs2-don-t-call-file_accessed-with-a-shared-glock.patch
and it can be found in the queue-3.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 3d1626889a64bd5a661544d582036a0a02104a60 Mon Sep 17 00:00:00 2001
From: Benjamin Marzinski <[email protected]>
Date: Tue, 6 Nov 2012 00:49:28 -0600
Subject: GFS2: Don't call file_accessed() with a shared glock
From: Benjamin Marzinski <[email protected]>
commit 3d1626889a64bd5a661544d582036a0a02104a60 upstream.
file_accessed() was being called by gfs2_mmap() with a shared glock. If it
needed to update the atime, it was crashing because it dirtied the inode in
gfs2_dirty_inode() without holding an exclusive lock. gfs2_dirty_inode()
checked if the caller was already holding a glock, but it didn't make sure that
the glock was in the exclusive state. Now, instead of calling file_accessed()
while holding the shared lock in gfs2_mmap(), file_accessed() is called after
grabbing and releasing the glock to update the inode. If file_accessed() needs
to update the atime, it will grab an exclusive lock in gfs2_dirty_inode().
gfs2_dirty_inode() now also checks to make sure that if the calling process has
already locked the glock, it has an exclusive lock.
Signed-off-by: Benjamin Marzinski <[email protected]>
Signed-off-by: Steven Whitehouse <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/gfs2/file.c | 12 +++++-------
fs/gfs2/super.c | 3 ++-
2 files changed, 7 insertions(+), 8 deletions(-)
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -515,15 +515,13 @@ static int gfs2_mmap(struct file *file,
struct gfs2_holder i_gh;
int error;
- gfs2_holder_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
- error = gfs2_glock_nq(&i_gh);
- if (error == 0) {
- file_accessed(file);
- gfs2_glock_dq(&i_gh);
- }
- gfs2_holder_uninit(&i_gh);
+ error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
+ &i_gh);
if (error)
return error;
+ /* grab lock to update inode */
+ gfs2_glock_dq_uninit(&i_gh);
+ file_accessed(file);
}
vma->vm_ops = &gfs2_vm_ops;
vma->vm_flags |= VM_CAN_NONLINEAR;
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -810,7 +810,8 @@ static void gfs2_dirty_inode(struct inod
return;
}
need_unlock = 1;
- }
+ } else if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE))
+ return;
if (current->journal_info == NULL) {
ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
Patches currently in stable-queue which might be from [email protected] are
queue-3.6/gfs2-don-t-call-file_accessed-with-a-shared-glock.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
