don't bother with tid_fd_revalidate() in lookups

what we want it for is actually updating inode metadata;
take _that_ into a separate helper and use it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index d38845e..f5de22a 100644 (file)
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -98,12 +98,27 @@ static bool tid_fd_mode(struct task_struct *task, unsigned fd, fmode_t *mode)
        return !!file;
 }
 
+static void tid_fd_update_inode(struct task_struct *task, struct inode *inode,
+                               fmode_t f_mode)
+{
+       task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
+
+       if (S_ISLNK(inode->i_mode)) {
+               unsigned i_mode = S_IFLNK;
+               if (f_mode & FMODE_READ)
+                       i_mode |= S_IRUSR | S_IXUSR;
+               if (f_mode & FMODE_WRITE)
+                       i_mode |= S_IWUSR | S_IXUSR;
+               inode->i_mode = i_mode;
+       }
+       security_task_to_inode(task, inode);
+}
+
 static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
 {
        struct task_struct *task;
        struct inode *inode;
        unsigned int fd;
-       fmode_t f_mode;
 
        if (flags & LOOKUP_RCU)
                return -ECHILD;
@@ -113,18 +128,9 @@ static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
        fd = proc_fd(inode);
 
        if (task) {
+               fmode_t f_mode;
                if (tid_fd_mode(task, fd, &f_mode)) {
-                       task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
-
-                       if (S_ISLNK(inode->i_mode)) {
-                               unsigned i_mode = S_IFLNK;
-                               if (f_mode & FMODE_READ)
-                                       i_mode |= S_IRUSR | S_IXUSR;
-                               if (f_mode & FMODE_WRITE)
-                                       i_mode |= S_IWUSR | S_IXUSR;
-                               inode->i_mode = i_mode;
-                       }
-                       security_task_to_inode(task, inode);
+                       tid_fd_update_inode(task, inode, f_mode);
                        put_task_struct(task);
                        return 1;
                }
@@ -168,34 +174,35 @@ static int proc_fd_link(struct dentry *dentry, struct path *path)
        return ret;
 }
 
+struct fd_data {
+       fmode_t mode;
+       unsigned fd;
+};
+
 static int
 proc_fd_instantiate(struct inode *dir, struct dentry *dentry,
                    struct task_struct *task, const void *ptr)
 {
-       unsigned fd = (unsigned long)ptr;
+       const struct fd_data *data = ptr;
        struct proc_inode *ei;
        struct inode *inode;
 
        inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK);
        if (!inode)
-               goto out;
+               return -ENOENT;
 
        ei = PROC_I(inode);
-       ei->fd = fd;
+       ei->fd = data->fd;
 
        inode->i_op = &proc_pid_link_inode_operations;
        inode->i_size = 64;
 
        ei->op.proc_get_link = proc_fd_link;
+       tid_fd_update_inode(task, inode, data->mode);
 
        d_set_d_op(dentry, &tid_fd_dentry_operations);
        d_add(dentry, inode);
-
-       /* Close the race of the process dying before we return the dentry */
-       if (tid_fd_revalidate(dentry, 0))
-               return 0;
- out:
-       return -ENOENT;
+       return 0;
 }
 
 static struct dentry *proc_lookupfd_common(struct inode *dir,
@@ -204,17 +211,16 @@ static struct dentry *proc_lookupfd_common(struct inode *dir,
 {
        struct task_struct *task = get_proc_task(dir);
        int result = -ENOENT;
-       unsigned fd = name_to_int(&dentry->d_name);
-       fmode_t f_mode;
+       struct fd_data data = {.fd = name_to_int(&dentry->d_name)};
 
        if (!task)
                goto out_no_task;
-       if (fd == ~0U)
+       if (data.fd == ~0U)
                goto out;
-       if (!tid_fd_mode(task, fd, &f_mode))
+       if (!tid_fd_mode(task, data.fd, &data.mode))
                goto out;
 
-       result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
+       result = instantiate(dir, dentry, task, &data);
 out:
        put_task_struct(task);
 out_no_task:
@@ -241,17 +247,22 @@ static int proc_readfd_common(struct file *file, struct dir_context *ctx,
        for (fd = ctx->pos - 2;
             fd < files_fdtable(files)->max_fds;
             fd++, ctx->pos++) {
+               struct file *f;
+               struct fd_data data;
                char name[10 + 1];
                int len;
 
-               if (!fcheck_files(files, fd))
+               f = fcheck_files(files, fd);
+               if (!f)
                        continue;
+               data.mode = f->f_mode;
                rcu_read_unlock();
+               data.fd = fd;
 
                len = snprintf(name, sizeof(name), "%u", fd);
                if (!proc_fill_cache(file, ctx,
                                     name, len, instantiate, p,
-                                    (void *)(unsigned long)fd))
+                                    &data))
                        goto out_fd_loop;
                cond_resched();
                rcu_read_lock();
@@ -313,27 +324,23 @@ static int
 proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry,
                        struct task_struct *task, const void *ptr)
 {
-       unsigned fd = (unsigned long)ptr;
+       const struct fd_data *data = ptr;
        struct proc_inode *ei;
        struct inode *inode;
 
        inode = proc_pid_make_inode(dir->i_sb, task, S_IFREG | S_IRUSR);
        if (!inode)
-               goto out;
+               return -ENOENT;
 
        ei = PROC_I(inode);
-       ei->fd = fd;
+       ei->fd = data->fd;
 
        inode->i_fop = &proc_fdinfo_file_operations;
+       tid_fd_update_inode(task, inode, 0);
 
        d_set_d_op(dentry, &tid_fd_dentry_operations);
        d_add(dentry, inode);
-
-       /* Close the race of the process dying before we return the dentry */
-       if (tid_fd_revalidate(dentry, 0))
-               return 0;
- out:
-       return -ENOENT;
+       return 0;
 }
 
 static struct dentry *