[PATCH 04/28] OCFS2 is screwy

Dave Hansen
2006-08-02T00:01:16Z

OCFS2 plays some games with i_nlink. It modifies it a bunch in
its unlink function, but rolls back the changes if an error
occurs. So, we can't just assume that iput_final() will happen
whenever i_nlink hits 0 in ocfs's unlink().

Create a helper function to do the hard work of i_nlink hitting
zero, and use it in ocfs2.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
---

lxc-dave/fs/libfs.c | 6 ++++++
lxc-dave/fs/ocfs2/namei.c | 8 +++++---
lxc-dave/include/linux/fs.h | 9 +++++++++
3 files changed, 20 insertions(+), 3 deletions(-)

diff -puN fs/ocfs2/namei.c~ofcfs-is-screwy fs/ocfs2/namei.c
--- lxc/fs/ocfs2/namei.c~ofcfs-is-screwy 2006-08-01 16:35:15.000000000 -0700
+++ lxc-dave/fs/ocfs2/namei.c 2006-08-01 16:35:16.000000000 -0700
@@ -909,6 +909,8 @@ static int ocfs2_unlink(struct inode *di
leave:
if (status < 0 && saved_nlink)
inode->i_nlink = saved_nlink;
+ if (inode->i_nlink == 0)
+ __inode_set_awaiting_final_iput(inode);

if (handle)
ocfs2_commit_trans(handle);
@@ -1329,7 +1331,7 @@ static int ocfs2_rename(struct inode *ol
}

if (new_inode) {
- new_inode->i_nlink--;
+ inode_drop_nlink(new_inode);
new_inode->i_ctime = CURRENT_TIME;
}
old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME;
@@ -1340,9 +1342,9 @@ static int ocfs2_rename(struct inode *ol
PARENT_INO(old_inode_de_bh->b_data) =
cpu_to_le64(OCFS2_I(new_dir)->ip_blkno);
status = ocfs2_journal_dirty(handle, old_inode_de_bh);
- old_dir->i_nlink--;
+ inode_drop_nlink(old_dir);
if (new_inode) {
- new_inode->i_nlink--;
+ inode_drop_nlink(new_inode);
} else {
new_dir->i_nlink++;
mark_inode_dirty(new_dir);
diff -puN fs/libfs.c~ofcfs-is-screwy fs/libfs.c
--- lxc/fs/libfs.c~ofcfs-is-screwy 2006-08-01 16:35:15.000000000 -0700
+++ lxc-dave/fs/libfs.c 2006-08-01 16:35:16.000000000 -0700
@@ -270,6 +270,11 @@ out:
return ret;
}

+void __inode_set_awaiting_final_iput(struct inode *inode)
+{
+}
+EXPORT_SYMBOL_GPL(inode_drop_nlink);
+
int simple_unlink(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
@@ -617,6 +622,7 @@ EXPORT_SYMBOL(simple_commit_write);
EXPORT_SYMBOL(simple_dir_inode_operations);
EXPORT_SYMBOL(simple_dir_operations);
EXPORT_SYMBOL(simple_empty);
+EXPORT_SYMBOL(__inode_set_awaiting_final_iput);
EXPORT_SYMBOL(d_alloc_name);
EXPORT_SYMBOL(simple_fill_super);
EXPORT_SYMBOL(simple_getattr);
diff -puN drivers/usb/core/inode.c~ofcfs-is-screwy drivers/usb/core/inode.c
diff -puN include/linux/fs.h~ofcfs-is-screwy include/linux/fs.h
--- lxc/include/linux/fs.h~ofcfs-is-screwy 2006-08-01 16:35:15.000000000 -0700
+++ lxc-dave/include/linux/fs.h 2006-08-01 16:35:16.000000000 -0700
@@ -1257,9 +1257,18 @@ static inline void inode_inc_link_count(
}

extern void __inode_set_awaiting_final_iput(struct inode *inode);
+static inline void inode_clear_nlink(struct inode *inode)
+{
+ if (inode->i_nlink)
+ __inode_set_awaiting_final_iput(inode);
+ inode->i_nlink = 0;
+}
+
static inline void inode_drop_nlink(struct inode *inode)
{
inode->i_nlink--;
+ if (!inode->i_nlink)
+ __inode_set_awaiting_final_iput(inode);
}

static inline void inode_dec_link_count(struct inode *inode)
_