proc: simplify proc_register calling conventions

Return registered entry on success, return NULL on failure and free the
passed in entry.  Also expose it in internal.h as we'll start using it
in proc_net.c soon.

Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Christoph Hellwig 2018-04-24 17:00:52 +02:00
parent 04015e3fa2
commit 61172eaea1
2 changed files with 20 additions and 26 deletions

View File

@ -346,13 +346,12 @@ static const struct inode_operations proc_dir_inode_operations = {
.setattr = proc_notify_change,
};
static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
/* returns the registered entry, or frees dp and returns NULL on failure */
struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
struct proc_dir_entry *dp)
{
int ret;
ret = proc_alloc_inum(&dp->low_ino);
if (ret)
return ret;
if (proc_alloc_inum(&dp->low_ino))
goto out_free_entry;
write_lock(&proc_subdir_lock);
dp->parent = dir;
@ -360,12 +359,16 @@ static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp
WARN(1, "proc_dir_entry '%s/%s' already registered\n",
dir->name, dp->name);
write_unlock(&proc_subdir_lock);
proc_free_inum(dp->low_ino);
return -EEXIST;
goto out_free_inum;
}
write_unlock(&proc_subdir_lock);
return 0;
return dp;
out_free_inum:
proc_free_inum(dp->low_ino);
out_free_entry:
pde_free(dp);
return NULL;
}
static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
@ -443,10 +446,7 @@ struct proc_dir_entry *proc_symlink(const char *name,
if (ent->data) {
strcpy((char*)ent->data,dest);
ent->proc_iops = &proc_link_inode_operations;
if (proc_register(parent, ent) < 0) {
pde_free(ent);
ent = NULL;
}
ent = proc_register(parent, ent);
} else {
pde_free(ent);
ent = NULL;
@ -470,11 +470,9 @@ struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode,
ent->proc_fops = &proc_dir_operations;
ent->proc_iops = &proc_dir_inode_operations;
parent->nlink++;
if (proc_register(parent, ent) < 0) {
pde_free(ent);
ent = proc_register(parent, ent);
if (!ent)
parent->nlink--;
ent = NULL;
}
}
return ent;
}
@ -505,11 +503,9 @@ struct proc_dir_entry *proc_create_mount_point(const char *name)
ent->proc_fops = NULL;
ent->proc_iops = NULL;
parent->nlink++;
if (proc_register(parent, ent) < 0) {
pde_free(ent);
ent = proc_register(parent, ent);
if (!ent)
parent->nlink--;
ent = NULL;
}
}
return ent;
}
@ -539,11 +535,7 @@ struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
pde->proc_fops = proc_fops;
pde->data = data;
pde->proc_iops = &proc_file_inode_operations;
if (proc_register(parent, pde) < 0)
goto out_free;
return pde;
out_free:
pde_free(pde);
return proc_register(parent, pde);
out:
return NULL;
}

View File

@ -162,6 +162,8 @@ extern bool proc_fill_cache(struct file *, struct dir_context *, const char *, i
/*
* generic.c
*/
struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
struct proc_dir_entry *dp);
extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
extern int proc_readdir(struct file *, struct dir_context *);