Commit 3e79d978 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

Pull vfs fixes from Al Viro:
 "These four commits are obvious fixes (a couple of fdget_pos()-related
  ones from Eric Biggers, prepend_name() fix, missing checks for false
  negatives from __lookup_mnt() in fs/namei.c)"

For now I'm pulling just the four obvious fixes, there's another four
pending in Al's 'for-linus' branch wrt the mnt_hash list that were more
involved.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  rcuwalk: recheck mount_lock after mountpoint crossing attempts
  make prepend_name() work correctly when called with negative *buflen
  vfs: Don't let __fdget_pos() get FMODE_PATH files
  vfs: atomic f_pos access in llseek()
parents b098d672 b37199e6

fs/dcache.c

+2 −2
Original line number Diff line number Diff line
@@ -2833,9 +2833,9 @@ static int prepend_name(char **buffer, int *buflen, struct qstr *name) 
	u32 dlen = ACCESS_ONCE(name->len);

	char *p;



	if (*buflen < dlen + 1)

		return -ENAMETOOLONG;

	*buflen -= dlen + 1;

	if (*buflen < 0)

		return -ENAMETOOLONG;

	p = *buffer -= dlen + 1;

	*p++ = '/';

	while (dlen--) {

fs/file.c

+4 −15
Original line number Diff line number Diff line
@@ -713,27 +713,16 @@ unsigned long __fdget_raw(unsigned int fd) 


unsigned long __fdget_pos(unsigned int fd)

{

	struct files_struct *files = current->files;

	struct file *file;

	unsigned long v;



	if (atomic_read(&files->count) == 1) {

		file = __fcheck_files(files, fd);

		v = 0;

	} else {

		file = __fget(fd, 0);

		v = FDPUT_FPUT;

	}

	if (!file)

		return 0;

	unsigned long v = __fdget(fd);

	struct file *file = (struct file *)(v & ~3);



	if (file->f_mode & FMODE_ATOMIC_POS) {

	if (file && (file->f_mode & FMODE_ATOMIC_POS)) {

		if (file_count(file) > 1) {

			v |= FDPUT_POS_UNLOCK;

			mutex_lock(&file->f_pos_lock);

		}

	}

	return v | (unsigned long)file;

	return v;

}



/*

fs/namei.c

+13 −16
Original line number Diff line number Diff line
@@ -1109,7 +1109,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, 
			return false;



		if (!d_mountpoint(path->dentry))

			break;

			return true;



		mounted = __lookup_mnt(path->mnt, path->dentry);

		if (!mounted)
@@ -1125,20 +1125,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, 
		 */

		*inode = path->dentry->d_inode;

	}

	return true;

}



static void follow_mount_rcu(struct nameidata *nd)

{

	while (d_mountpoint(nd->path.dentry)) {

		struct mount *mounted;

		mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);

		if (!mounted)

			break;

		nd->path.mnt = &mounted->mnt;

		nd->path.dentry = mounted->mnt.mnt_root;

		nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);

	}

	return read_seqretry(&mount_lock, nd->m_seq);

}



static int follow_dotdot_rcu(struct nameidata *nd)
@@ -1166,7 +1153,17 @@ static int follow_dotdot_rcu(struct nameidata *nd) 
			break;

		nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);

	}

	follow_mount_rcu(nd);

	while (d_mountpoint(nd->path.dentry)) {

		struct mount *mounted;

		mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);

		if (!mounted)

			break;

		nd->path.mnt = &mounted->mnt;

		nd->path.dentry = mounted->mnt.mnt_root;

		nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);

		if (!read_seqretry(&mount_lock, nd->m_seq))

			goto failed;

	}

	nd->inode = nd->path.dentry->d_inode;

	return 0;

fs/read_write.c

+2 −2
Original line number Diff line number Diff line
@@ -307,7 +307,7 @@ SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, 
		unsigned int, whence)

{

	int retval;

	struct fd f = fdget(fd);

	struct fd f = fdget_pos(fd);

	loff_t offset;



	if (!f.file)
@@ -327,7 +327,7 @@ SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high, 
			retval = 0;

	}

out_putf:

	fdput(f);

	fdput_pos(f);

	return retval;

}

#endif

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