Miklos Szeredi eed8100766 vfs: check unlinked ancestors before mount ...

We check submounts before doing d_drop() on a non-empty directory dentry in
NFS (have_submounts()), but we do not exclude a racing mount.  Nor do we
prevent mounts to be added to the disconnected subtree using relative paths
after the d_drop().

This patch fixes these issues by checking for unlinked (unhashed, non-root)
ancestors before proceeding with the mount.  This is done with rename
seqlock taken for write and with ->d_lock grabbed on each ancestor in turn,
including our dentry itself.  This ensures that the only one of
check_submounts_and_drop() or has_unlinked_ancestor() can succeed.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2013-09-05 16:23:50 -04:00

..

9p

Merge tag 'for-linus-3.11-merge-window-part-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

2013-07-11 10:21:23 -07:00

adfs

Don't pass inode to ->d_hash() and ->d_compare()

2013-06-29 12:57:36 +04:00

affs

Don't pass inode to ->d_hash() and ->d_compare()

2013-06-29 12:57:36 +04:00

afs

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

2013-07-03 09:10:19 -07:00

autofs4

helper for reading ->d_count

2013-07-05 18:59:33 +04:00

befs

[readdir] convert befs

2013-06-29 12:56:55 +04:00

bfs

bfs: iget_locked() doesn't return an ERR_PTR

2013-08-24 12:10:22 -04:00

btrfs

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

2013-09-05 08:50:26 -07:00

cachefiles

mm: remove lru parameter from __pagevec_lru_add and remove parts of pagevec API

2013-07-03 16:07:31 -07:00

ceph

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

2013-07-09 12:39:10 -07:00

cifs

direct-io: Handle O_(D)SYNC AIO

2013-09-04 09:23:46 -04:00

coda

helper for reading ->d_count

2013-07-05 18:59:33 +04:00

configfs

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

2013-07-14 11:42:26 -07:00

cramfs

[readdir] convert f2fs

2013-06-29 12:56:46 +04:00

debugfs

debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs)

2013-07-31 12:16:31 -04:00

devpts

…

dlm

dlm: remove signal blocking

2013-08-12 15:22:43 -05:00

ecryptfs

Merge tag 'ecryptfs-3.11-rc1-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs

2013-07-11 10:20:18 -07:00

efivarfs

efivarfs: we can use simple_lookup() now

2013-07-14 17:48:35 +04:00

efs

efs: iget_locked() doesn't return an ERR_PTR()

2013-08-24 12:10:22 -04:00

exofs

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2013-07-02 09:39:34 -07:00

exportfs

[readdir] constify ->actor

2013-06-29 12:57:05 +04:00

ext2

[O_TMPFILE] it's still short a few helpers, but infrastructure should be OK now...

2013-06-29 12:57:10 +04:00

ext3

ext4: Fix misspellings using 'codespell' tool

2013-08-28 14:40:12 -04:00

ext4

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

2013-09-05 08:50:26 -07:00

f2fs

f2fs: fix readdir incorrectness

2013-07-08 13:35:48 +04:00

fat

fatfs: add FAT_IOCTL_GET_VOLUME_ID

2013-07-09 10:33:25 -07:00

freevxfs

[readdir] convert freevxfs

2013-06-29 12:56:53 +04:00

fscache

FS-Cache: Don't use spin_is_locked() in assertions

2013-06-19 14:16:47 +01:00

fuse

Merge 3.11-rc3 into driver-core-next

2013-07-29 12:30:13 -07:00

gfs2

GFS2: Check for glock already held in gfs2_getxattr

2013-08-19 09:33:57 +01:00

hfs

Don't pass inode to ->d_hash() and ->d_compare()

2013-06-29 12:57:36 +04:00

hfsplus

Don't pass inode to ->d_hash() and ->d_compare()

2013-06-29 12:57:36 +04:00

hostfs

[readdir] convert hostfs

2013-06-29 12:56:59 +04:00

hpfs

Merge branch 'hpfs' from Mikulas Patocka

2013-07-04 11:22:55 -07:00

hppfs

clean up scary strncpy(dst, src, strlen(src)) uses

2013-07-03 16:07:41 -07:00

hugetlbfs

cope with potentially long ->d_dname() output for shmem/hugetlb

2013-08-24 12:10:17 -04:00

isofs

Don't pass inode to ->d_hash() and ->d_compare()

2013-06-29 12:57:36 +04:00

jbd

jbd: change journal_invalidatepage() to accept length

2013-05-21 23:26:36 -04:00

jbd2

jbd2: Fix endian mixing problems in the checksumming code

2013-08-28 14:59:58 -04:00

jffs2

[readdir] convert jffs2

2013-06-29 12:56:47 +04:00

jfs

jfs: fix readdir cookie incompatibility with NFSv4

2013-08-15 17:22:29 -05:00

lockd

LOCKD: Don't call utsname()->nodename from nlmclnt_setlockargs

2013-08-05 15:03:46 -04:00

logfs

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2013-07-02 09:39:34 -07:00

minix

minix: bug widening a binary "not" operation

2013-06-29 12:57:35 +04:00

ncpfs

ncpfs: fix error return code in ncp_parse_options()

2013-07-09 10:33:25 -07:00

nfs

NFSv4: Fix up nfs4_proc_lookup_mountpoint

2013-08-07 20:47:26 -04:00

nfs_common

…

nfsd

nfsd: racy access to ->d_name in nsfd4_encode_path()

2013-09-03 22:50:28 -04:00

nilfs2

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

2013-09-05 08:50:26 -07:00

nls

…

notify

fsnotify: update comments concerning locking scheme

2013-07-09 10:33:20 -07:00

ntfs

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2013-07-02 09:39:34 -07:00

ocfs2

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

2013-09-05 08:50:26 -07:00

omfs

[readdir] convert omfs

2013-06-29 12:56:37 +04:00

openpromfs

[readdir] convert openpromfs

2013-06-29 12:56:32 +04:00

proc

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

2013-08-25 12:25:38 -07:00

pstore

pstore/ram: (really) fix undefined usage of rounddown_pow_of_two

2013-08-30 15:57:01 -07:00

qnx4

[readdir] convert qnx4

2013-06-29 12:56:38 +04:00

qnx6

[readdir] convert qnx6

2013-06-29 12:56:39 +04:00

quota

quota: provide interface for readding allocated space into reserved space

2013-08-17 09:32:32 -04:00

ramfs

…

reiserfs

reiserfs: fix deadlock in umount

2013-08-05 17:37:37 +04:00

romfs

[readdir] convert romfs

2013-06-29 12:56:29 +04:00

squashfs

[readdir] convert squashfs

2013-06-29 12:56:28 +04:00

sysfs

sysfs: group.c: fix up kerneldoc

2013-08-22 09:23:28 -07:00

sysv

Don't pass inode to ->d_hash() and ->d_compare()

2013-06-29 12:57:36 +04:00

ubifs

Merge tag 'upstream-3.11-rc1' of git://git.infradead.org/linux-ubifs

2013-07-05 12:08:47 -07:00

udf

udf: provide ->tmpfile()

2013-06-29 12:57:12 +04:00

ufs

[readdir] simple local unixlike: switch to ->iterate()

2013-06-29 12:46:47 +04:00

xfs

direct-io: Implement generic deferred AIO completions

2013-09-04 09:23:46 -04:00

aio.c

aio: fix wrong comment in aio_complete()

2013-07-03 16:08:06 -07:00

anon_inodes.c

…

attr.c

…

bad_inode.c

[readdir] ->readdir() is gone

2013-06-29 12:57:04 +04:00

binfmt_aout.c

mm: remove free_area_cache

2013-07-10 18:11:34 -07:00

binfmt_elf_fdpic.c

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2013-05-02 10:16:16 -07:00

binfmt_elf.c

mm: remove free_area_cache

2013-07-10 18:11:34 -07:00

binfmt_em86.c

…

binfmt_flat.c

…

binfmt_misc.c

binfmt_misc: reuse string_unescape_inplace()

2013-04-30 17:04:03 -07:00

binfmt_script.c

…

binfmt_som.c

…

bio-integrity.c

…

bio.c

Merge branch 'for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2013-09-03 18:25:03 -07:00

block_dev.c

direct-io: Handle O_(D)SYNC AIO

2013-09-04 09:23:46 -04:00

buffer.c

mm: vmscan: take page buffers dirty and locked state into account

2013-07-03 16:07:29 -07:00

char_dev.c

…

compat_binfmt_elf.c

…

compat_ioctl.c

compat.c: LOOP_CLR_FD is taken care of in loop.c itself...

2013-06-29 12:46:44 +04:00

compat.c

[readdir] constify ->actor

2013-06-29 12:57:05 +04:00

coredump.c

coredump: '% at the end' shouldn't bypass core_uses_pid logic

2013-07-03 16:08:02 -07:00

coredump.h

…

dcache.c

vfs: check unlinked ancestors before mount

2013-09-05 16:23:50 -04:00

dcookies.c

…

direct-io.c

direct-io: Handle O_(D)SYNC AIO

2013-09-04 09:23:46 -04:00

drop_caches.c

…

eventfd.c

…

eventpoll.c

switch epoll_ctl() to fdget

2013-09-03 23:04:44 -04:00

exec.c

Fix TLB gather virtual address range invalidation corner cases

2013-08-16 08:52:46 -07:00

fcntl.c

vfs: add missing check for __O_TMPFILE in fcntl_init()

2013-08-05 18:25:32 +04:00

fhandle.c

…

file_table.c

only regular files with FMODE_WRITE need to be on s_files

2013-09-03 22:50:28 -04:00

file.c

don't bother with deferred freeing of fdtables

2013-05-01 17:31:42 -04:00

filesystems.c

…

fs_struct.c

…

fs-writeback.c

mm/writeback: don't check force_wait to handle bdi->work_list

2013-07-09 10:33:22 -07:00

generic_acl.c

…

inode.c

constify touch_atime()

2013-09-03 22:52:45 -04:00

internal.h

vfs: check unlinked ancestors before mount

2013-09-05 16:23:50 -04:00

ioctl.c

…

ioprio.c

…

Kconfig

…

Kconfig.binfmt

fs: make binfmt support for #! scripts modular and removable

2013-04-30 17:04:04 -07:00

libfs.c

make simple_lookup() usable for filesystems that set ->s_d_op

2013-07-14 17:43:25 +04:00

locks.c

locks: move file_lock_list to a set of percpu hlist_heads and convert file_lock_lock to an lglock

2013-07-08 13:36:42 +04:00

Makefile

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

2013-05-01 17:51:54 -07:00

mbcache.c

…

mount.h

…

mpage.c

…

namei.c

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

2013-09-05 08:50:26 -07:00

namespace.c

vfs: check unlinked ancestors before mount

2013-09-05 16:23:50 -04:00

no-block.c

…

open.c

switch fchmod() to fdget

2013-09-03 23:04:45 -04:00

pipe.c

aio: don't include aio.h in sched.h

2013-05-07 20:16:25 -07:00

pnode.c

vfs: Fix invalid ida_remove() call

2013-05-31 15:16:33 -04:00

pnode.h

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

2013-05-01 17:51:54 -07:00

posix_acl.c

…

proc_namespace.c

…

read_write.c

vfs: export lseek_execute() to modules

2013-07-03 16:23:27 +04:00

readdir.c

[readdir] constify ->actor

2013-06-29 12:57:05 +04:00

select.c

net: rename include/net/ll_poll.h to include/net/busy_poll.h

2013-07-10 17:08:27 -07:00

seq_file.c

seq_file: add seq_list_*_percpu helpers

2013-07-08 13:36:41 +04:00

signalfd.c

…

splice.c

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

2013-07-03 09:10:19 -07:00

stack.c

…

stat.c

quota: provide interface for readding allocated space into reserved space

2013-08-17 09:32:32 -04:00

statfs.c

…

super.c

direct-io: Implement generic deferred AIO completions

2013-09-04 09:23:46 -04:00

sync.c

…

timerfd.c

timerfd: Add alarm timers

2013-05-29 12:57:34 -07:00

utimes.c

…

xattr_acl.c

…

xattr.c

…