[PATCH 31/32] IGET: Stop HPPFS from using iget() and read_inode() [try #2]

David Howells
2007-10-04T16:09:50Z

Stop the HPPFS filesystem from using iget() and read_inode(). Provide an
hppfs_iget(), and call that instead of iget(). hppfs_iget() then uses
iget_locked() directly and returns a proper error code instead of an inode in
the event of an error.

hppfs_fill_sb_common() returns any error incurred when getting the root inode
instead of EINVAL.

Note that the contents of hppfs_kern.c need to be examined:

(*) The HPPFS inode retains a pointer to the proc dentry it is shadowing, but
whilst it does appear to retain a reference to it, it doesn't appear to
destroy the reference if the inode goes away.

(*) hppfs_iget() should perhaps subsume init_inode() and hppfs_read_inode().

(*) It would appear that all hppfs inodes are the same inode because iget()
was being called with inode number 0, which forms the lookup key.

Signed-off-by: David Howells <dhowells@redhat.com>
---

fs/hppfs/hppfs_kern.c | 27 ++++++++++++++++++++++-----
1 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/fs/hppfs/hppfs_kern.c b/fs/hppfs/hppfs_kern.c
index affb741..a1e1f0f 100644
--- a/fs/hppfs/hppfs_kern.c
+++ b/fs/hppfs/hppfs_kern.c
@@ -155,6 +155,20 @@ static void hppfs_read_inode(struct inode *ino)
ino->i_blocks = proc_ino->i_blocks;
}

+static struct inode *hppfs_iget(struct super_block *sb)
+{
+ struct inode *inode;
+
+ inode = iget_locked(sb, 0);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+ if (inode->i_state & I_NEW) {
+ hppfs_read_inode(inode);
+ unlock_new_inode(inode);
+ }
+ return inode;
+}
+
static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
struct nameidata *nd)
{
@@ -190,9 +204,11 @@ static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
if(IS_ERR(proc_dentry))
return(proc_dentry);

- inode = iget(ino->i_sb, 0);
- if(inode == NULL)
+ inode = hppfs_iget(ino->i_sb);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
goto out_dput;
+ }

err = init_inode(inode, proc_dentry);
if(err)
@@ -652,7 +668,6 @@ static void hppfs_destroy_inode(struct inode *inode)
static const struct super_operations hppfs_sbops = {
.alloc_inode = hppfs_alloc_inode,
.destroy_inode = hppfs_destroy_inode,
- .read_inode = hppfs_read_inode,
.delete_inode = hppfs_delete_inode,
.statfs = hppfs_statfs,
};
@@ -745,9 +760,11 @@ static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
sb->s_magic = HPPFS_SUPER_MAGIC;
sb->s_op = &hppfs_sbops;

- root_inode = iget(sb, 0);
- if(root_inode == NULL)
+ root_inode = hppfs_iget(sb);
+ if (IS_ERR(root_inode)) {
+ err = PTR_ERR(root_inode);
goto out;
+ }

err = init_inode(root_inode, proc_sb->s_root);
if(err)