diff options
| -rw-r--r-- | fs/proc/base.c | 133 |
1 files changed, 111 insertions, 22 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 6d00ccc48c1..7832efbd43a 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1674,6 +1674,108 @@ static struct inode_operations proc_self_inode_operations = { }; /* + * proc base + * + * These are the directory entries in the root directory of /proc + * that properly belong to the /proc filesystem, as they describe + * describe something that is process related. + */ +static struct pid_entry proc_base_stuff[] = { + NOD(PROC_TGID_INO, "self", S_IFLNK|S_IRWXUGO, + &proc_self_inode_operations, NULL, {}), + {} +}; + +/* + * Exceptional case: normally we are not allowed to unhash a busy + * directory. In this case, however, we can do it - no aliasing problems + * due to the way we treat inodes. + */ +static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd) +{ + struct inode *inode = dentry->d_inode; + struct task_struct *task = get_proc_task(inode); + if (task) { + put_task_struct(task); + return 1; + } + d_drop(dentry); + return 0; +} + +static struct dentry_operations proc_base_dentry_operations = +{ + .d_revalidate = proc_base_revalidate, + .d_delete = pid_delete_dentry, +}; + +static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) +{ + struct inode *inode; + struct dentry *error; + struct task_struct *task = get_proc_task(dir); + struct pid_entry *p; + struct proc_inode *ei; + + error = ERR_PTR(-ENOENT); + inode = NULL; + + if (!task) + goto out_no_task; + + /* Lookup the directory entry */ + for (p = proc_base_stuff; p->name; p++) { + if (p->len != dentry->d_name.len) + continue; + if (!memcmp(dentry->d_name.name, p->name, p->len)) + break; + } + if (!p->name) + goto out; + + /* Allocate the inode */ + error = ERR_PTR(-ENOMEM); + inode = new_inode(dir->i_sb); + if (!inode) + goto out; + + /* Initialize the inode */ + ei = PROC_I(inode); + inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; + inode->i_ino = fake_ino(0, p->type); + + /* + * grab the reference to the task. + */ + ei->pid = get_pid(task_pid(task)); + if (!ei->pid) + goto out_iput; + + inode->i_uid = 0; + inode->i_gid = 0; + inode->i_mode = p->mode; + if (S_ISDIR(inode->i_mode)) + inode->i_nlink = 2; + if (S_ISLNK(inode->i_mode)) + inode->i_size = 64; + if (p->iop) + inode->i_op = p->iop; + if (p->fop) + inode->i_fop = p->fop; + ei->op = p->op; + dentry->d_op = &proc_base_dentry_operations; + d_add(dentry, inode); + error = NULL; +out: + put_task_struct(task); +out_no_task: + return error; +out_iput: + iput(inode); + goto out; +} + +/* * Thread groups */ static struct file_operations proc_task_operations; @@ -1819,24 +1921,12 @@ struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct struct dentry *result = ERR_PTR(-ENOENT); struct task_struct *task; struct inode *inode; - struct proc_inode *ei; unsigned tgid; - if (dentry->d_name.len == 4 && !memcmp(dentry->d_name.name,"self",4)) { - inode = new_inode(dir->i_sb); - if (!inode) - return ERR_PTR(-ENOMEM); - ei = PROC_I(inode); - inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; - inode->i_ino = fake_ino(0, PROC_TGID_INO); - ei->pde = NULL; - inode->i_mode = S_IFLNK|S_IRWXUGO; - inode->i_uid = inode->i_gid = 0; - inode->i_size = 64; - inode->i_op = &proc_self_inode_operations; - d_add(dentry, inode); - return NULL; - } + result = proc_base_lookup(dir, dentry); + if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT) + goto out; + tgid = name_to_int(dentry); if (tgid == ~0U) goto out; @@ -1922,12 +2012,11 @@ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) struct task_struct *task; int tgid; - if (!nr) { - ino_t ino = fake_ino(0,PROC_TGID_INO); - if (filldir(dirent, "self", 4, filp->f_pos, ino, DT_LNK) < 0) - return 0; - filp->f_pos++; - nr++; + for (; nr < (ARRAY_SIZE(proc_base_stuff) - 1); filp->f_pos++, nr++) { + struct pid_entry *p = &proc_base_stuff[nr]; + if (filldir(dirent, p->name, p->len, filp->f_pos, + fake_ino(0, p->type), p->mode >> 12) < 0) + goto out; } tgid = filp->f_pos - TGID_OFFSET; |