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authorBenjamin Marzinski <bmarzins@redhat.com>2012-11-06 00:49:28 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-11-26 12:14:19 -0800
commit3707c973f834b0035e611ceb89162d3f6081e262 (patch)
treef4e5a0b6c22a3ec213e149fbf927039945c03a7e
parente01d83515635e7176cb69f1ac2c59ad1e39e8a63 (diff)
GFS2: Don't call file_accessed() with a shared glock
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 <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/gfs2/file.c12
-rw-r--r--fs/gfs2/super.c3
2 files changed, 7 insertions, 8 deletions
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 382000ffac1f..07cc71ffe5d9 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -515,15 +515,13 @@ 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 fc3168f47a14..12ff463cba0b 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -810,7 +810,8 @@ 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);