From patchwork Thu Dec 13 13:59:42 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [217/241] GFS2: Don't call file_accessed() with a shared glock Date: Thu, 13 Dec 2012 03:59:42 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 206062 Message-Id: <1355407206-17100-218-git-send-email-herton.krzesinski@canonical.com> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Benjamin Marzinski , Steven Whitehouse 3.5.7.2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Marzinski 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 Signed-off-by: Steven Whitehouse Signed-off-by: Herton Ronaldo Krzesinski --- fs/gfs2/file.c | 12 +++++------- fs/gfs2/super.c | 3 ++- 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 31b199f..a8a81d7 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -492,15 +492,13 @@ static int gfs2_mmap(struct file *file, struct vm_area_struct *vma) 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; diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c index 713e621..12769a2 100644 --- a/fs/gfs2/super.c +++ b/fs/gfs2/super.c @@ -800,7 +800,8 @@ static void gfs2_dirty_inode(struct inode *inode, int flags) 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);