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>

1 files changed, 44 insertions, 37 deletions

diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index d38845ecc408..f5de22a9e9e0 100644
--- 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 *