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-rw-r--r--fs/proc/base.c133
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;