GFS2: high time to take some time over atime

Until now, we've used the same scheme as GFS1 for atime. This has failed
since atime is a per vfsmnt flag, not a per fs flag and as such the
"noatime" flag was not getting passed down to the filesystems. This
patch removes all the "special casing" around atime updates and we
simply use the VFS's atime code.

The net result is that GFS2 will now support all the same atime related
mount options of any other filesystem on a per-vfsmnt basis. We do lose
the "lazy atime" updates, but we gain "relatime". We could add lazy
atime to the VFS at a later date, if there is a requirement for that
variant still - I suspect relatime will be enough.

Also we lose about 100 lines of code after this patch has been applied,
and I have a suspicion that it will speed things up a bit, even when
atime is "on". So it seems like a nice clean up as well.

From a user perspective, everything stays the same except the loss of
the per-fs atime quantum tweekable (ought to be per-vfsmnt at the very
least, and to be honest I don't think anybody ever used it) and that a
number of options which were ignored before now work correctly.

Please let me know if you've got any comments. I'm pushing this out
early so that you can all see what my plans are.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 8 insertions, 8 deletions

diff --git a/fs/gfs2/ops_file.c b/fs/gfs2/ops_file.c
index e9a366d4411c..3a747f8e2188 100644
--- a/fs/gfs2/ops_file.c
+++ b/fs/gfs2/ops_file.c
@@ -89,8 +89,8 @@ static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
         u64 offset = file->f_pos;
         int error;
 
-        gfs2_holder_init(dip->i_gl, LM_ST_SHARED, GL_ATIME, &d_gh);
-        error = gfs2_glock_nq_atime(&d_gh);
+        gfs2_holder_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
+        error = gfs2_glock_nq(&d_gh);
         if (error) {
                 gfs2_holder_uninit(&d_gh);
                 return error;
@@ -153,8 +153,8 @@ static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
         int error;
         u32 fsflags;
 
-        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
-        error = gfs2_glock_nq_atime(&gh);
+        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
+        error = gfs2_glock_nq(&gh);
         if (error)
                 return error;
 
@@ -351,8 +351,8 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct page *page)
         struct gfs2_alloc *al;
         int ret;
 
-        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &gh);
-        ret = gfs2_glock_nq_atime(&gh);
+        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
+        ret = gfs2_glock_nq(&gh);
         if (ret)
                 goto out;
 
@@ -434,8 +434,8 @@ 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, GL_ATIME, &i_gh);
-        error = gfs2_glock_nq_atime(&i_gh);
+        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
+        error = gfs2_glock_nq(&i_gh);
         if (error) {
                 gfs2_holder_uninit(&i_gh);
                 return error;