Skip to content

Commit

Permalink
[PATCH] sanitize hppfs
Browse files Browse the repository at this point in the history 
* hppfs_iget() and its users are racy; there's no need to pollute icache
  anyway, new_inode() works fine and is safe, unlike the current kludges
  (these relied on overwriting ->i_ino before another iget_locked() gets
  to that one - and did it after unlocking).
* merge hppfs_iget()/init_inode()/hppfs_read_inode(), while we are
  at it.
* to pass proper vfsmount to dentry_open() store the reference
  in hppfs superblock.

Signed-off-by: Al Viro <[email protected]>
 --
  • Loading branch information
Al Viro committed Mar 19, 2008
1 parent 1dd0dd1 commit f382d6e
Showing 1 changed file with 34 additions and 79 deletions.
113 changes: 34 additions & 79 deletions fs/hppfs/hppfs_kern.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,8 +18,7 @@
#include <asm/uaccess.h>
#include "os.h"

static int init_inode(struct inode *inode, struct dentry *dentry,
struct vfsmount *mnt);
static struct inode *get_inode(struct super_block *, struct dentry *);

struct hppfs_data {
struct list_head list;
Expand All @@ -35,7 +34,6 @@ struct hppfs_private {

struct hppfs_inode_info {
struct dentry *proc_dentry;
struct vfsmount *proc_mnt;
struct inode vfs_inode;
};

Expand Down Expand Up @@ -137,40 +135,6 @@ static int file_removed(struct dentry *dentry, const char *file)
return 0;
}

static void hppfs_read_inode(struct inode *ino)
{
struct inode *proc_ino;

if (HPPFS_I(ino)->proc_dentry == NULL)
return;

proc_ino = HPPFS_I(ino)->proc_dentry->d_inode;
ino->i_uid = proc_ino->i_uid;
ino->i_gid = proc_ino->i_gid;
ino->i_atime = proc_ino->i_atime;
ino->i_mtime = proc_ino->i_mtime;
ino->i_ctime = proc_ino->i_ctime;
ino->i_ino = proc_ino->i_ino;
ino->i_mode = proc_ino->i_mode;
ino->i_nlink = proc_ino->i_nlink;
ino->i_size = proc_ino->i_size;
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)
{
Expand Down Expand Up @@ -206,23 +170,14 @@ static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
if (IS_ERR(proc_dentry))
return proc_dentry;

inode = hppfs_iget(ino->i_sb);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
err = -ENOMEM;
inode = get_inode(ino->i_sb, proc_dentry);
if (!inode)
goto out_dput;
}

err = init_inode(inode, proc_dentry, HPPFS_I(ino)->proc_mnt);
if (err)
goto out_put;

hppfs_read_inode(inode);

d_add(dentry, inode);
return NULL;

out_put:
iput(inode);
out_dput:
dput(proc_dentry);
out:
Expand Down Expand Up @@ -489,7 +444,7 @@ static int hppfs_open(struct inode *inode, struct file *file)
goto out_free2;

proc_dentry = HPPFS_I(inode)->proc_dentry;
proc_mnt = HPPFS_I(inode)->proc_mnt;
proc_mnt = inode->i_sb->s_fs_info;

/* XXX This isn't closed anywhere */
data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt),
Expand Down Expand Up @@ -547,7 +502,7 @@ static int hppfs_dir_open(struct inode *inode, struct file *file)
goto out;

proc_dentry = HPPFS_I(inode)->proc_dentry;
proc_mnt = HPPFS_I(inode)->proc_mnt;
proc_mnt = inode->i_sb->s_fs_info;
data->proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt),
file_mode(file->f_mode));
err = PTR_ERR(data->proc_file);
Expand Down Expand Up @@ -659,7 +614,6 @@ static struct inode *hppfs_alloc_inode(struct super_block *sb)
return NULL;

hi->proc_dentry = NULL;
hi->proc_mnt = NULL;
inode_init_once(&hi->vfs_inode);
return &hi->vfs_inode;
}
Expand All @@ -676,7 +630,7 @@ static void hppfs_destroy_inode(struct inode *inode)

static void hppfs_put_super(struct super_block *sb)
{
mntput(HPPFS_I(sb->s_root->d_inode)->proc_mnt);
mntput(sb->s_fs_info);
}

static const struct super_operations hppfs_sbops = {
Expand All @@ -696,7 +650,7 @@ static int hppfs_readlink(struct dentry *dentry, char __user *buffer,
int ret;

proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
proc_mnt = HPPFS_I(dentry->d_inode)->proc_mnt;
proc_mnt = dentry->d_sb->s_fs_info;

proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt), O_RDONLY);
if (IS_ERR(proc_file))
Expand All @@ -717,7 +671,7 @@ static void* hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
void *ret;

proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
proc_mnt = HPPFS_I(dentry->d_inode)->proc_mnt;
proc_mnt = dentry->d_sb->s_fs_info;

proc_file = dentry_open(dget(proc_dentry), mntget(proc_mnt), O_RDONLY);
if (IS_ERR(proc_file))
Expand All @@ -739,9 +693,14 @@ static const struct inode_operations hppfs_link_iops = {
.follow_link = hppfs_follow_link,
};

static int init_inode(struct inode *inode, struct dentry *dentry,
struct vfsmount *mnt)
static struct inode *get_inode(struct super_block *sb, struct dentry *dentry)
{
struct inode *proc_ino = dentry->d_inode;
struct inode *inode = new_inode(sb);

if (!inode)
return ERR_PTR(-ENOMEM);

if (S_ISDIR(dentry->d_inode->i_mode)) {
inode->i_op = &hppfs_dir_iops;
inode->i_fop = &hppfs_dir_fops;
Expand All @@ -754,50 +713,46 @@ static int init_inode(struct inode *inode, struct dentry *dentry,
}

HPPFS_I(inode)->proc_dentry = dentry;
HPPFS_I(inode)->proc_mnt = mnt;

inode->i_uid = proc_ino->i_uid;
inode->i_gid = proc_ino->i_gid;
inode->i_atime = proc_ino->i_atime;
inode->i_mtime = proc_ino->i_mtime;
inode->i_ctime = proc_ino->i_ctime;
inode->i_ino = proc_ino->i_ino;
inode->i_mode = proc_ino->i_mode;
inode->i_nlink = proc_ino->i_nlink;
inode->i_size = proc_ino->i_size;
inode->i_blocks = proc_ino->i_blocks;

return 0;
}

static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
{
struct inode *root_inode;
struct file_system_type *procfs;
struct vfsmount *proc_mnt;
int err;
int err = -ENOENT;

err = -ENOENT;
procfs = get_fs_type("proc");
if (!procfs)
goto out;

proc_mnt = vfs_kern_mount(procfs, 0, procfs->name, NULL);
put_filesystem(procfs);
proc_mnt = do_kern_mount("proc", 0, "proc", NULL);
if (IS_ERR(proc_mnt))
goto out;

sb->s_blocksize = 1024;
sb->s_blocksize_bits = 10;
sb->s_magic = HPPFS_SUPER_MAGIC;
sb->s_op = &hppfs_sbops;

root_inode = hppfs_iget(sb);
if (IS_ERR(root_inode)) {
err = PTR_ERR(root_inode);
goto out;
}

err = init_inode(root_inode, proc_mnt->mnt_sb->s_root, proc_mnt);
if (err)
goto out_iput;
sb->s_fs_info = proc_mnt;

err = -ENOMEM;
root_inode = get_inode(sb, proc_mnt->mnt_sb->s_root);
if (!root_inode)
goto out_mntput;

sb->s_root = d_alloc_root(root_inode);
if (!sb->s_root)
goto out_iput;

hppfs_read_inode(root_inode);

return 0;

out_iput:
Expand Down

0 comments on commit f382d6e

Please sign in to comment.