Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs update from Al Viro:

 - big one - consolidation of descriptor-related logics; almost all of
   that is moved to fs/file.c

   (BTW, I'm seriously tempted to rename the result to fd.c.  As it is,
   we have a situation when file_table.c is about handling of struct
   file and file.c is about handling of descriptor tables; the reasons
   are historical - file_table.c used to be about a static array of
   struct file we used to have way back).

   A lot of stray ends got cleaned up and converted to saner primitives,
   disgusting mess in android/binder.c is still disgusting, but at least
   doesn't poke so much in descriptor table guts anymore.  A bunch of
   relatively minor races got fixed in process, plus an ext4 struct file
   leak.

 - related thing - fget_light() partially unuglified; see fdget() in
   there (and yes, it generates the code as good as we used to have).

 - also related - bits of Cyrill's procfs stuff that got entangled into
   that work; _not_ all of it, just the initial move to fs/proc/fd.c and
   switch of fdinfo to seq_file.

 - Alex's fs/coredump.c spiltoff - the same story, had been easier to
   take that commit than mess with conflicts.  The rest is a separate
   pile, this was just a mechanical code movement.

 - a few misc patches all over the place.  Not all for this cycle,
   there'll be more (and quite a few currently sit in akpm's tree)."

Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
  MAX_LFS_FILESIZE should be a loff_t
  compat: fs: Generic compat_sys_sendfile implementation
  fs: push rcu_barrier() from deactivate_locked_super() to filesystems
  btrfs: reada_extent doesn't need kref for refcount
  coredump: move core dump functionality into its own file
  coredump: prevent double-free on an error path in core dumper
  usb/gadget: fix misannotations
  fcntl: fix misannotations
  ceph: don't abuse d_delete() on failure exits
  hypfs: ->d_parent is never NULL or negative
  vfs: delete surplus inode NULL check
  switch simple cases of fget_light to fdget
  new helpers: fdget()/fdput()
  switch o2hb_region_dev_write() to fget_light()
  proc_map_files_readdir(): don't bother with grabbing files
  make get_file() return its argument
  vhost_set_vring(): turn pollstart/pollstop into bool
  switch prctl_set_mm_exe_file() to fget_light()
  switch xfs_find_handle() to fget_light()
  switch xfs_swapext() to fget_light()
  ...

1 files changed, 11 insertions, 406 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index acd1960c28a2..d295af993677 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -90,6 +90,7 @@
 #endif
 #include <trace/events/oom.h>
 #include "internal.h"
+#include "fd.h"
 
 /* NOTE:
  *	Implementing inode permission operations in /proc is almost
@@ -136,8 +137,6 @@ struct pid_entry {
 		NULL, &proc_single_file_operations,	\
 		{ .proc_show = show } )
 
-static int proc_fd_permission(struct inode *inode, int mask);
-
 /*
  * Count the number of hardlinks for the pid_entry table, excluding the .
  * and .. links.
@@ -1500,7 +1499,7 @@ out:
 	return error;
 }
 
-static const struct inode_operations proc_pid_link_inode_operations = {
+const struct inode_operations proc_pid_link_inode_operations = {
 	.readlink	= proc_pid_readlink,
 	.follow_link	= proc_pid_follow_link,
 	.setattr	= proc_setattr,
@@ -1509,21 +1508,6 @@ static const struct inode_operations proc_pid_link_inode_operations = {
 
 /* building an inode */
 
-static int task_dumpable(struct task_struct *task)
-{
-	int dumpable = 0;
-	struct mm_struct *mm;
-
-	task_lock(task);
-	mm = task->mm;
-	if (mm)
-		dumpable = get_dumpable(mm);
-	task_unlock(task);
-	if(dumpable == 1)
-		return 1;
-	return 0;
-}
-
 struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
 {
 	struct inode * inode;
@@ -1649,15 +1633,6 @@ int pid_revalidate(struct dentry *dentry, unsigned int flags)
 	return 0;
 }
 
-static int pid_delete_dentry(const struct dentry * dentry)
-{
-	/* Is the task we represent dead?
-	 * If so, then don't put the dentry on the lru list,
-	 * kill it immediately.
-	 */
-	return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
-}
-
 const struct dentry_operations pid_dentry_operations =
 {
 	.d_revalidate	= pid_revalidate,
@@ -1720,289 +1695,6 @@ end_instantiate:
 	return filldir(dirent, name, len, filp->f_pos, ino, type);
 }
 
-static unsigned name_to_int(struct dentry *dentry)
-{
-	const char *name = dentry->d_name.name;
-	int len = dentry->d_name.len;
-	unsigned n = 0;
-
-	if (len > 1 && *name == '0')
-		goto out;
-	while (len-- > 0) {
-		unsigned c = *name++ - '0';
-		if (c > 9)
-			goto out;
-		if (n >= (~0U-9)/10)
-			goto out;
-		n *= 10;
-		n += c;
-	}
-	return n;
-out:
-	return ~0U;
-}
-
-#define PROC_FDINFO_MAX 64
-
-static int proc_fd_info(struct inode *inode, struct path *path, char *info)
-{
-	struct task_struct *task = get_proc_task(inode);
-	struct files_struct *files = NULL;
-	struct file *file;
-	int fd = proc_fd(inode);
-
-	if (task) {
-		files = get_files_struct(task);
-		put_task_struct(task);
-	}
-	if (files) {
-		/*
-		 * We are not taking a ref to the file structure, so we must
-		 * hold ->file_lock.
-		 */
-		spin_lock(&files->file_lock);
-		file = fcheck_files(files, fd);
-		if (file) {
-			unsigned int f_flags;
-			struct fdtable *fdt;
-
-			fdt = files_fdtable(files);
-			f_flags = file->f_flags & ~O_CLOEXEC;
-			if (close_on_exec(fd, fdt))
-				f_flags |= O_CLOEXEC;
-
-			if (path) {
-				*path = file->f_path;
-				path_get(&file->f_path);
-			}
-			if (info)
-				snprintf(info, PROC_FDINFO_MAX,
-					 "pos:\t%lli\n"
-					 "flags:\t0%o\n",
-					 (long long) file->f_pos,
-					 f_flags);
-			spin_unlock(&files->file_lock);
-			put_files_struct(files);
-			return 0;
-		}
-		spin_unlock(&files->file_lock);
-		put_files_struct(files);
-	}
-	return -ENOENT;
-}
-
-static int proc_fd_link(struct dentry *dentry, struct path *path)
-{
-	return proc_fd_info(dentry->d_inode, path, NULL);
-}
-
-static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
-{
-	struct inode *inode;
-	struct task_struct *task;
-	int fd;
-	struct files_struct *files;
-	const struct cred *cred;
-
-	if (flags & LOOKUP_RCU)
-		return -ECHILD;
-
-	inode = dentry->d_inode;
-	task = get_proc_task(inode);
-	fd = proc_fd(inode);
-
-	if (task) {
-		files = get_files_struct(task);
-		if (files) {
-			struct file *file;
-			rcu_read_lock();
-			file = fcheck_files(files, fd);
-			if (file) {
-				unsigned f_mode = file->f_mode;
-
-				rcu_read_unlock();
-				put_files_struct(files);
-
-				if (task_dumpable(task)) {
-					rcu_read_lock();
-					cred = __task_cred(task);
-					inode->i_uid = cred->euid;
-					inode->i_gid = cred->egid;
-					rcu_read_unlock();
-				} else {
-					inode->i_uid = GLOBAL_ROOT_UID;
-					inode->i_gid = GLOBAL_ROOT_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);
-				put_task_struct(task);
-				return 1;
-			}
-			rcu_read_unlock();
-			put_files_struct(files);
-		}
-		put_task_struct(task);
-	}
-	d_drop(dentry);
-	return 0;
-}
-
-static const struct dentry_operations tid_fd_dentry_operations =
-{
-	.d_revalidate	= tid_fd_revalidate,
-	.d_delete	= pid_delete_dentry,
-};
-
-static struct dentry *proc_fd_instantiate(struct inode *dir,
-	struct dentry *dentry, struct task_struct *task, const void *ptr)
-{
-	unsigned fd = (unsigned long)ptr;
- 	struct inode *inode;
- 	struct proc_inode *ei;
-	struct dentry *error = ERR_PTR(-ENOENT);
-
-	inode = proc_pid_make_inode(dir->i_sb, task);
-	if (!inode)
-		goto out;
-	ei = PROC_I(inode);
-	ei->fd = fd;
-
-	inode->i_mode = S_IFLNK;
-	inode->i_op = &proc_pid_link_inode_operations;
-	inode->i_size = 64;
-	ei->op.proc_get_link = proc_fd_link;
-	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))
-		error = NULL;
-
- out:
-	return error;
-}
-
-static struct dentry *proc_lookupfd_common(struct inode *dir,
-					   struct dentry *dentry,
-					   instantiate_t instantiate)
-{
-	struct task_struct *task = get_proc_task(dir);
-	unsigned fd = name_to_int(dentry);
-	struct dentry *result = ERR_PTR(-ENOENT);
-
-	if (!task)
-		goto out_no_task;
-	if (fd == ~0U)
-		goto out;
-
-	result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
-out:
-	put_task_struct(task);
-out_no_task:
-	return result;
-}
-
-static int proc_readfd_common(struct file * filp, void * dirent,
-			      filldir_t filldir, instantiate_t instantiate)
-{
-	struct dentry *dentry = filp->f_path.dentry;
-	struct inode *inode = dentry->d_inode;
-	struct task_struct *p = get_proc_task(inode);
-	unsigned int fd, ino;
-	int retval;
-	struct files_struct * files;
-
-	retval = -ENOENT;
-	if (!p)
-		goto out_no_task;
-	retval = 0;
-
-	fd = filp->f_pos;
-	switch (fd) {
-		case 0:
-			if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
-				goto out;
-			filp->f_pos++;
-		case 1:
-			ino = parent_ino(dentry);
-			if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
-				goto out;
-			filp->f_pos++;
-		default:
-			files = get_files_struct(p);
-			if (!files)
-				goto out;
-			rcu_read_lock();
-			for (fd = filp->f_pos-2;
-			     fd < files_fdtable(files)->max_fds;
-			     fd++, filp->f_pos++) {
-				char name[PROC_NUMBUF];
-				int len;
-				int rv;
-
-				if (!fcheck_files(files, fd))
-					continue;
-				rcu_read_unlock();
-
-				len = snprintf(name, sizeof(name), "%d", fd);
-				rv = proc_fill_cache(filp, dirent, filldir,
-						     name, len, instantiate, p,
-						     (void *)(unsigned long)fd);
-				if (rv < 0)
-					goto out_fd_loop;
-				rcu_read_lock();
-			}
-			rcu_read_unlock();
-out_fd_loop:
-			put_files_struct(files);
-	}
-out:
-	put_task_struct(p);
-out_no_task:
-	return retval;
-}
-
-static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
-				    unsigned int flags)
-{
-	return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
-}
-
-static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
-{
-	return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
-}
-
-static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
-				      size_t len, loff_t *ppos)
-{
-	char tmp[PROC_FDINFO_MAX];
-	int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
-	if (!err)
-		err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
-	return err;
-}
-
-static const struct file_operations proc_fdinfo_file_operations = {
-	.open           = nonseekable_open,
-	.read		= proc_fdinfo_read,
-	.llseek		= no_llseek,
-};
-
-static const struct file_operations proc_fd_operations = {
-	.read		= generic_read_dir,
-	.readdir	= proc_readfd,
-	.llseek		= default_llseek,
-};
-
 #ifdef CONFIG_CHECKPOINT_RESTORE
 
 /*
@@ -2121,7 +1813,7 @@ out:
 }
 
 struct map_files_info {
-	struct file	*file;
+	fmode_t		mode;
 	unsigned long	len;
 	unsigned char	name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */
 };
@@ -2130,13 +1822,10 @@ static struct dentry *
 proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
 			   struct task_struct *task, const void *ptr)
 {
-	const struct file *file = ptr;
+	fmode_t mode = (fmode_t)(unsigned long)ptr;
 	struct proc_inode *ei;
 	struct inode *inode;
 
-	if (!file)
-		return ERR_PTR(-ENOENT);
-
 	inode = proc_pid_make_inode(dir->i_sb, task);
 	if (!inode)
 		return ERR_PTR(-ENOENT);
@@ -2148,9 +1837,9 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
 	inode->i_size = 64;
 	inode->i_mode = S_IFLNK;
 
-	if (file->f_mode & FMODE_READ)
+	if (mode & FMODE_READ)
 		inode->i_mode |= S_IRUSR;
-	if (file->f_mode & FMODE_WRITE)
+	if (mode & FMODE_WRITE)
 		inode->i_mode |= S_IWUSR;
 
 	d_set_d_op(dentry, &tid_map_files_dentry_operations);
@@ -2194,7 +1883,8 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
 	if (!vma)
 		goto out_no_vma;
 
-	result = proc_map_files_instantiate(dir, dentry, task, vma->vm_file);
+	result = proc_map_files_instantiate(dir, dentry, task,
+			(void *)(unsigned long)vma->vm_file->f_mode);
 
 out_no_vma:
 	up_read(&mm->mmap_sem);
@@ -2295,8 +1985,7 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
 				if (++pos <= filp->f_pos)
 					continue;
 
-				get_file(vma->vm_file);
-				info.file = vma->vm_file;
+				info.mode = vma->vm_file->f_mode;
 				info.len = snprintf(info.name,
 						sizeof(info.name), "%lx-%lx",
 						vma->vm_start, vma->vm_end);
@@ -2311,19 +2000,11 @@ proc_map_files_readdir(struct file *filp, void *dirent, filldir_t filldir)
 			ret = proc_fill_cache(filp, dirent, filldir,
 					      p->name, p->len,
 					      proc_map_files_instantiate,
-					      task, p->file);
+					      task,
+					      (void *)(unsigned long)p->mode);
 			if (ret)
 				break;
 			filp->f_pos++;
-			fput(p->file);
-		}
-		for (; i < nr_files; i++) {
-			/*
-			 * In case of error don't forget
-			 * to put rest of file refs.
-			 */
-			p = flex_array_get(fa, i);
-			fput(p->file);
 		}
 		if (fa)
 			flex_array_free(fa);
@@ -2345,82 +2026,6 @@ static const struct file_operations proc_map_files_operations = {
 
 #endif /* CONFIG_CHECKPOINT_RESTORE */
 
-/*
- * /proc/pid/fd needs a special permission handler so that a process can still
- * access /proc/self/fd after it has executed a setuid().
- */
-static int proc_fd_permission(struct inode *inode, int mask)
-{
-	int rv = generic_permission(inode, mask);
-	if (rv == 0)
-		return 0;
-	if (task_pid(current) == proc_pid(inode))
-		rv = 0;
-	return rv;
-}
-
-/*
- * proc directories can do almost nothing..
- */
-static const struct inode_operations proc_fd_inode_operations = {
-	.lookup		= proc_lookupfd,
-	.permission	= proc_fd_permission,
-	.setattr	= proc_setattr,
-};
-
-static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
-	struct dentry *dentry, struct task_struct *task, const void *ptr)
-{
-	unsigned fd = (unsigned long)ptr;
- 	struct inode *inode;
- 	struct proc_inode *ei;
-	struct dentry *error = ERR_PTR(-ENOENT);
-
-	inode = proc_pid_make_inode(dir->i_sb, task);
-	if (!inode)
-		goto out;
-	ei = PROC_I(inode);
-	ei->fd = fd;
-	inode->i_mode = S_IFREG | S_IRUSR;
-	inode->i_fop = &proc_fdinfo_file_operations;
-	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))
-		error = NULL;
-
- out:
-	return error;
-}
-
-static struct dentry *proc_lookupfdinfo(struct inode *dir,
-					struct dentry *dentry,
-					unsigned int flags)
-{
-	return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
-}
-
-static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
-{
-	return proc_readfd_common(filp, dirent, filldir,
-				  proc_fdinfo_instantiate);
-}
-
-static const struct file_operations proc_fdinfo_operations = {
-	.read		= generic_read_dir,
-	.readdir	= proc_readfdinfo,
-	.llseek		= default_llseek,
-};
-
-/*
- * proc directories can do almost nothing..
- */
-static const struct inode_operations proc_fdinfo_inode_operations = {
-	.lookup		= proc_lookupfdinfo,
-	.setattr	= proc_setattr,
-};
-
-
 static struct dentry *proc_pident_instantiate(struct inode *dir,
 	struct dentry *dentry, struct task_struct *task, const void *ptr)
 {