[GFS2] inode_diet: Replace inode.u.generic_ip with inode.i_private (gfs)
The following patches reduce the size of the VFS inode structure by 28 bytes
on a UP x86. (It would be more on an x86_64 system). This is a 10% reduction
in the inode size on a UP kernel that is configured in a production mode
(i.e., with no spinlock or other debugging functions enabled; if you want to
save memory taken up by in-core inodes, the first thing you should do is
disable the debugging options; they are responsible for a huge amount of bloat
in the VFS inode structure).
This patch:
The filesystem or device-specific pointer in the inode is inside a union,
which is pretty pointless given that all 30+ users of this field have been
using the void pointer. Get rid of the union and rename it to i_private, with
a comment to explain who is allowed to use the void pointer. This is just a
cleanup, but it allows us to reuse the union 'u' for something something where
the union will actually be used.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c
index 9c3aedd..ca94a83 100644
--- a/fs/dlm/debug_fs.c
+++ b/fs/dlm/debug_fs.c
@@ -282,7 +282,7 @@
return ret;
seq = file->private_data;
- seq->private = inode->u.generic_ip;
+ seq->private = inode->i_private;
return 0;
}
@@ -301,7 +301,7 @@
static int waiters_open(struct inode *inode, struct file *file)
{
- file->private_data = inode->u.generic_ip;
+ file->private_data = inode->i_private;
return 0;
}
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index ac9535b..784d145 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -160,7 +160,7 @@
if (inode->i_state & I_NEW) {
struct gfs2_sbd *sdp = GFS2_SB(inode);
umode_t mode = DT2IF(type);
- inode->u.generic_ip = ip;
+ inode->i_private = ip;
inode->i_mode = mode;
if (S_ISREG(mode)) {
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index d3708af..7317991 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -78,7 +78,7 @@
mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS);
aspace->i_mapping->a_ops = &aspace_aops;
aspace->i_size = ~0ULL;
- aspace->u.generic_ip = NULL;
+ aspace->i_private = NULL;
insert_inode_hash(aspace);
}
return aspace;
diff --git a/fs/gfs2/ops_super.c b/fs/gfs2/ops_super.c
index 8cfda64..06f06f7 100644
--- a/fs/gfs2/ops_super.c
+++ b/fs/gfs2/ops_super.c
@@ -53,7 +53,7 @@
struct gfs2_inode *ip = GFS2_I(inode);
/* Check this is a "normal" inode */
- if (inode->u.generic_ip) {
+ if (inode->i_private) {
if (current->flags & PF_MEMALLOC)
return 0;
if (sync)
@@ -280,7 +280,7 @@
* serves to contain an address space (see rgrp.c, meta_io.c)
* which therefore doesn't have its own glocks.
*/
- if (inode->u.generic_ip) {
+ if (inode->i_private) {
struct gfs2_inode *ip = GFS2_I(inode);
gfs2_glock_inode_squish(inode);
gfs2_assert(inode->i_sb->s_fs_info, ip->i_gl->gl_state == LM_ST_UNLOCKED);
@@ -381,7 +381,7 @@
struct gfs2_holder gh;
int error;
- if (!inode->u.generic_ip)
+ if (!inode->i_private)
goto out;
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, &gh);