On Sat, Apr 26, 2008 at 05:17:55PM +0800, WANG Cong wrote:
> > +static struct inode *get_inode(struct super_block *, struct dentry *);
> > +
> > +struct hppfs_data {
> > +   struct list_head list;
> > +   char contents[PAGE_SIZE - sizeof(struct list_head)];
> > +};
> > +
> > +struct hppfs_private {
> > +   struct file *proc_file;
> > +   int host_fd;
> > +   loff_t len;
> > +   struct hppfs_data *contents;
> > +};
> > +
> > +struct hppfs_inode_info {
> > +   struct dentry *proc_dentry;
> > +   struct inode vfs_inode;
> > +};
> > +
> > +static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode)
> > +{
> > +   return container_of(inode, struct hppfs_inode_info, vfs_inode);
> > +}
> > +
> > +#define HPPFS_SUPER_MAGIC 0xb00000ee
> 
> 
> These can be put into a single header, e.g. hppfs.h.

Why, when this one C file is the only user?

> > +static char *dentry_name(struct dentry *dentry, int extra)
> > +{
> > +   struct dentry *parent;
> > +   char *root, *name;
> > +   const char *seg_name;
> > +   int len, seg_len;
> > +
> > +   len = 0;
> > +   parent = dentry;
> 
> These can be put into initialization, I think, that's more readable.

Yup.

> > +   if (fd > 0) {
> > +           os_close_file(fd);
> > +           return 1;
> > +   }
> 
> 
> How about 'fd < 0' ?

OK, that would remove the braces at least...

> > +           new = kmalloc(sizeof(*data), GFP_KERNEL);
> > +           if (new == 0) {
> 
> 
> Using NULL is better, at least sparse complains about this. ;)

Good, I never liked using 0 (or !ptr) in place of NULL anyway.

> > +static int hppfs_filldir(void *d, const char *name, int size,
> > +                    loff_t offset, u64 inode, unsigned int type)
> > +{
> > +   struct hppfs_dirent *dirent = d;
> > +
> > +   if (file_removed(dirent->dentry, name))
> > +           return 0;
> 
> If returning 0 indicates success, this is wrong, since file_removed() may
> return -ENOMEM.
> 
> Or I miss something that is too obvious? ;-)

Oops, nice spotting.

See what you think about the patch below...

                        Jeff

-- 
Work email - jdike at linux dot intel dot com

Index: linux-2.6.22/fs/hppfs/hppfs.c
===================================================================
--- linux-2.6.22.orig/fs/hppfs/hppfs.c  2008-04-28 11:21:38.000000000 -0400
+++ linux-2.6.22/fs/hppfs/hppfs.c       2008-04-28 11:34:58.000000000 -0400
@@ -64,13 +64,11 @@ static int is_pid(struct dentry *dentry)
 
 static char *dentry_name(struct dentry *dentry, int extra)
 {
-       struct dentry *parent;
-       char *root, *name;
+       struct dentry *parent = dentry;
+       char *root = "proc", *name;
        const char *seg_name;
-       int len, seg_len;
+       int len = 0, seg_len;
 
-       len = 0;
-       parent = dentry;
        while (parent->d_parent != parent) {
                if (is_pid(parent))
                        len += strlen("pid") + 1;
@@ -78,7 +76,6 @@ static char *dentry_name(struct dentry *
                parent = parent->d_parent;
        }
 
-       root = "proc";
        len += strlen(root);
        name = kmalloc(len + extra + 1, GFP_KERNEL);
        if (name == NULL)
@@ -128,11 +125,11 @@ static int file_removed(struct dentry *d
 
        fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
        kfree(host_file);
-       if (fd > 0) {
-               os_close_file(fd);
-               return 1;
-       }
-       return 0;
+       if (fd < 0)
+               return 0;
+
+       os_close_file(fd);
+       return 1;
 }
 
 static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
@@ -210,11 +207,10 @@ static ssize_t read_proc(struct file *fi
 
 static ssize_t hppfs_read_file(int fd, char __user *buf, ssize_t count)
 {
-       ssize_t n;
+       ssize_t n = -ENOMEM;
        int cur, err;
        char *new_buf;
 
-       n = -ENOMEM;
        new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
        if (new_buf == NULL) {
                printk(KERN_ERR "hppfs_read_file : kmalloc failed\n");
@@ -271,8 +267,10 @@ static ssize_t hppfs_read(struct file *f
                        count = hppfs->len - off;
                rem = copy_to_user(buf, &data->contents[off], count);
                *ppos += count - rem;
-               if (rem > 0)
+               if (rem == count)
                        return -EFAULT;
+               else if (rem > 0)
+                       return count - rem;
        } else if (hppfs->host_fd != -1) {
                err = os_seek_file(hppfs->host_fd, *ppos);
                if (err) {
@@ -380,7 +378,7 @@ static struct hppfs_data *hppfs_get_data
                        break;
 
                new = kmalloc(sizeof(*data), GFP_KERNEL);
-               if (new == 0) {
+               if (new == NULL) {
                        printk(KERN_ERR "hppfs_get_data : data allocation "
                               "failed\n");
                        err = -ENOMEM;
@@ -551,8 +549,11 @@ static int hppfs_filldir(void *d, const 
                         loff_t offset, u64 inode, unsigned int type)
 {
        struct hppfs_dirent *dirent = d;
+       int gone = file_removed(dirent->dentry, name);
 
-       if (file_removed(dirent->dentry, name))
+       if (gone < 0)
+               return gone;
+       else if (gone)
                return 0;
 
        return (*dirent->filldir)(dirent->vfs_dirent, name, size, offset,

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