[PATCH 30/32] IGET: Stop HOSTFS from using iget() and read_inode() [try #2]

David Howells
2007-10-04T16:10:22Z

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

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

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

(*) hostfs_iget() should perhaps subsume init_inode() and hostfs_read_inode().

(*) It would appear that all hostfs 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/hostfs/hostfs_kern.c | 58 ++++++++++++++++++++++++++++++++---------------
1 files changed, 39 insertions(+), 19 deletions(-)

diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index c778620..c6a456a 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -208,7 +208,7 @@ static char *follow_link(char *link)
return ERR_PTR(n);
}

-static int read_inode(struct inode *ino)
+static int hostfs_read_inode(struct inode *ino)
{
char *name;
int err = 0;
@@ -238,6 +238,25 @@ static int read_inode(struct inode *ino)
return err;
}

+static struct inode *hostfs_iget(struct super_block *sb)
+{
+ struct inode *inode;
+ long ret;
+
+ inode = iget_locked(sb, 0);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+ if (inode->i_state & I_NEW) {
+ ret = hostfs_read_inode(inode);
+ if (ret < 0) {
+ iget_failed(inode);
+ return ERR_PTR(ret);
+ }
+ unlock_new_inode(inode);
+ }
+ return inode;
+}
+
int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf)
{
/* do_statfs uses struct statfs64 internally, but the linux kernel
@@ -305,17 +324,11 @@ static void hostfs_destroy_inode(struct inode *inode)
kfree(HOSTFS_I(inode));
}

-static void hostfs_read_inode(struct inode *inode)
-{
- read_inode(inode);
-}
-
static const struct super_operations hostfs_sbops = {
.alloc_inode = hostfs_alloc_inode,
.drop_inode = generic_delete_inode,
.delete_inode = hostfs_delete_inode,
.destroy_inode = hostfs_destroy_inode,
- .read_inode = hostfs_read_inode,
.statfs = hostfs_statfs,
};

@@ -584,9 +597,11 @@ int hostfs_create(struct inode *dir, struct dentry *dentry, int mode,
char *name;
int error, fd;

- error = -ENOMEM;
- inode = iget(dir->i_sb, 0);
- if(inode == NULL) goto out;
+ inode = hostfs_iget(dir->i_sb);
+ if (IS_ERR(inode)) {
+ error = PTR_ERR(inode);
+ goto out;
+ }

error = init_inode(inode, dentry);
if(error)
@@ -627,10 +642,11 @@ struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry,
char *name;
int err;

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

err = init_inode(inode, dentry);
if(err)
@@ -748,11 +764,13 @@ int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
{
struct inode *inode;
char *name;
- int err = -ENOMEM;
+ int err;

- inode = iget(dir->i_sb, 0);
- if(inode == NULL)
+ inode = hostfs_iget(dir->i_sb);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
goto out;
+ }

err = init_inode(inode, dentry);
if(err)
@@ -973,9 +991,11 @@ static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent)

sprintf(host_root_path, "%s/%s", root_ino, req_root);

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

err = init_inode(root_inode, NULL);
if(err)
@@ -991,7 +1011,7 @@ static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent)
if(sb->s_root == NULL)
goto out_put;

- err = read_inode(root_inode);
+ err = hostfs_read_inode(root_inode);
if(err){
/* No iput in this case because the dput does that for us */
dput(sb->s_root);