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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git…
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…/viro/vfs

Pull vfs fixes from Al Viro.

 - fix io_destroy()/aio_complete() race

 - the vfs_open() change to get rid of open_check_o_direct() boilerplate
   was nice, but buggy. Al has a patch avoiding a revert, but that's
   definitely not a last-day fodder, so for now revert it is...

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Revert "fs: fold open_check_o_direct into do_dentry_open"
  fix io_destroy()/aio_complete() race
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Linus Torvalds committed Jun 3, 2018
2 parents 874cd33 + af04fad commit 325e14f
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Showing 4 changed files with 34 additions and 21 deletions.
3 changes: 1 addition & 2 deletions fs/aio.c
Original file line number Diff line number Diff line change
Expand Up @@ -634,9 +634,8 @@ static void free_ioctx_users(struct percpu_ref *ref)
while (!list_empty(&ctx->active_reqs)) {
req = list_first_entry(&ctx->active_reqs,
struct aio_kiocb, ki_list);

list_del_init(&req->ki_list);
kiocb_cancel(req);
list_del_init(&req->ki_list);
}

spin_unlock_irq(&ctx->ctx_lock);
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1 change: 1 addition & 0 deletions fs/internal.h
Original file line number Diff line number Diff line change
Expand Up @@ -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 *);

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7 changes: 6 additions & 1 deletion fs/namei.c
Original file line number Diff line number Diff line change
Expand Up @@ -3367,7 +3367,9 @@ static int do_last(struct nameidata *nd,
goto out;
*opened |= FILE_OPENED;
opened:
error = ima_file_check(file, op->acc_mode, *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);
out:
Expand Down Expand Up @@ -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:
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44 changes: 26 additions & 18 deletions fs/open.c
Original file line number Diff line number Diff line change
Expand Up @@ -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 *),
Expand All @@ -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)) {
Expand Down Expand Up @@ -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:
Expand 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;
}

/**
Expand Down Expand Up @@ -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;

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