Commit af04fadc authored by Al Viro's avatar Al Viro Committed by Linus Torvalds

Revert "fs: fold open_check_o_direct into do_dentry_open"

This reverts commit cab64df1.

Having vfs_open() in some cases drop the reference to
struct file combined with

	error = vfs_open(path, f, cred);
	if (error) {
		put_filp(f);
		return ERR_PTR(error);
	}
	return f;

is flat-out wrong.  It used to be

		error = vfs_open(path, f, cred);
		if (!error) {
			/* from now on we need fput() to dispose of f */
			error = open_check_o_direct(f);
			if (error) {
				fput(f);
				f = ERR_PTR(error);
			}
		} else {
			put_filp(f);
			f = ERR_PTR(error);
		}

and sure, having that open_check_o_direct() boilerplate gotten rid of is
nice, but not that way...

Worse, another call chain (via finish_open()) is FUBAR now wrt
FILE_OPENED handling - in that case we get error returned, with file
already hit by fput() *AND* FILE_OPENED not set.  Guess what happens in
path_openat(), when it hits

	if (!(opened & FILE_OPENED)) {
		BUG_ON(!error);
		put_filp(file);
	}

The root cause of all that crap is that the callers of do_dentry_open()
have no way to tell which way did it fail; while that could be fixed up
(by passing something like int *opened to do_dentry_open() and have it
marked if we'd called ->open()), it's probably much too late in the
cycle to do so right now.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4faa9996
......@@ -125,6 +125,7 @@ int do_fchmodat(int dfd, const char __user *filename, umode_t mode);
int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
int flag);
extern int open_check_o_direct(struct file *f);
extern int vfs_open(const struct path *, struct file *, const struct cred *);
extern struct file *filp_clone_open(struct file *);
......
......@@ -3367,6 +3367,8 @@ static int do_last(struct nameidata *nd,
goto out;
*opened |= FILE_OPENED;
opened:
error = open_check_o_direct(file);
if (!error)
error = ima_file_check(file, op->acc_mode, *opened);
if (!error && will_truncate)
error = handle_truncate(file);
......@@ -3447,6 +3449,9 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags,
error = finish_open(file, child, NULL, opened);
if (error)
goto out2;
error = open_check_o_direct(file);
if (error)
fput(file);
out2:
mnt_drop_write(path.mnt);
out:
......
......@@ -724,6 +724,16 @@ SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
return ksys_fchown(fd, user, group);
}
int open_check_o_direct(struct file *f)
{
/* NB: we're sure to have correct a_ops only after f_op->open */
if (f->f_flags & O_DIRECT) {
if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO)
return -EINVAL;
}
return 0;
}
static int do_dentry_open(struct file *f,
struct inode *inode,
int (*open)(struct inode *, struct file *),
......@@ -745,7 +755,7 @@ static int do_dentry_open(struct file *f,
if (unlikely(f->f_flags & O_PATH)) {
f->f_mode = FMODE_PATH;
f->f_op = &empty_fops;
goto done;
return 0;
}
if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) {
......@@ -798,12 +808,7 @@ static int do_dentry_open(struct file *f,
f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
done:
/* NB: we're sure to have correct a_ops only after f_op->open */
error = -EINVAL;
if ((f->f_flags & O_DIRECT) &&
(!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO))
goto out_fput;
return 0;
cleanup_all:
......@@ -818,9 +823,6 @@ static int do_dentry_open(struct file *f,
f->f_path.dentry = NULL;
f->f_inode = NULL;
return error;
out_fput:
fput(f);
return error;
}
/**
......@@ -918,14 +920,20 @@ struct file *dentry_open(const struct path *path, int flags,
BUG_ON(!path->mnt);
f = get_empty_filp();
if (IS_ERR(f))
return f;
if (!IS_ERR(f)) {
f->f_flags = flags;
error = vfs_open(path, f, cred);
if (!error) {
/* from now on we need fput() to dispose of f */
error = open_check_o_direct(f);
if (error) {
fput(f);
f = ERR_PTR(error);
}
} else {
put_filp(f);
return ERR_PTR(error);
f = ERR_PTR(error);
}
}
return f;
}
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment