WSL2-Linux-Kernel/fs
Josh Boyer e096d0c7e2 lockdep: Add helper function for dir vs file i_mutex annotation
Purely in-memory filesystems do not use the inode hash as the dcache
tells us if an entry already exists.  As a result, they do not call
unlock_new_inode, and thus directory inodes do not get put into a
different lockdep class for i_sem.

We need the different lockdep classes, because the locking order for
i_mutex is different for directory inodes and regular inodes.  Directory
inodes can do "readdir()", which takes i_mutex *before* possibly taking
mm->mmap_sem (due to a page fault while copying the directory entry to
user space).

In contrast, regular inodes can be mmap'ed, which takes mm->mmap_sem
before accessing i_mutex.

The two cases can never happen for the same inode, so no real deadlock
can occur, but without the different lockdep classes, lockdep cannot
understand that.  As a result, if CONFIG_DEBUG_LOCK_ALLOC is set, this
can lead to false positives from lockdep like below:

    find/645 is trying to acquire lock:
     (&mm->mmap_sem){++++++}, at: [<ffffffff81109514>] might_fault+0x5c/0xac

    but task is already holding lock:
     (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffff81149f34>]
    vfs_readdir+0x5b/0xb4

    which lock already depends on the new lock.

    the existing dependency chain (in reverse order) is:

    -> #1 (&sb->s_type->i_mutex_key#15){+.+.+.}:
          [<ffffffff8108ac26>] lock_acquire+0xbf/0x103
          [<ffffffff814db822>] __mutex_lock_common+0x4c/0x361
          [<ffffffff814dbc46>] mutex_lock_nested+0x40/0x45
          [<ffffffff811daa87>] hugetlbfs_file_mmap+0x82/0x110
          [<ffffffff81111557>] mmap_region+0x258/0x432
          [<ffffffff811119dd>] do_mmap_pgoff+0x2ac/0x306
          [<ffffffff81111b4f>] sys_mmap_pgoff+0x118/0x16a
          [<ffffffff8100c858>] sys_mmap+0x22/0x24
          [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b

    -> #0 (&mm->mmap_sem){++++++}:
          [<ffffffff8108a4bc>] __lock_acquire+0xa1a/0xcf7
          [<ffffffff8108ac26>] lock_acquire+0xbf/0x103
          [<ffffffff81109541>] might_fault+0x89/0xac
          [<ffffffff81149cff>] filldir+0x6f/0xc7
          [<ffffffff811586ea>] dcache_readdir+0x67/0x205
          [<ffffffff81149f54>] vfs_readdir+0x7b/0xb4
          [<ffffffff8114a073>] sys_getdents+0x7e/0xd1
          [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b

This patch moves the directory vs file lockdep annotation into a helper
function that can be called by in-memory filesystems and has hugetlbfs
call it.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-25 10:50:18 -07:00
..
9p switch posix_acl_equiv_mode() to umode_t * 2011-08-01 02:10:06 -04:00
adfs
affs fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers 2011-07-20 20:47:59 -04:00
afs AFS: Fix silly characters in a comment 2011-07-20 20:48:03 -04:00
autofs4 autofs4: fix debug printk warning uncovered by cleanup 2011-08-08 12:02:43 -07:00
befs befs: Validate length of long symbolic links. 2011-08-17 13:31:24 -07:00
bfs bfs: remove unnecessary dentry_unhash on dir rename 2011-05-28 01:02:50 -04:00
btrfs Btrfs: fix 64 bit divide problem 2011-08-21 07:02:00 -07:00
cachefiles kill useless checks for sb->s_op == NULL 2011-07-20 01:44:21 -04:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2011-07-26 13:38:50 -07:00
cifs update cifs version to 1.75 2011-08-18 16:55:10 +00:00
coda fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers 2011-07-20 20:47:59 -04:00
configfs configfs: remove unnecessary dentry_unhash on rmdir, dir rename 2011-05-28 01:02:54 -04:00
cramfs cramfs: get_cramfs_inode() returns ERR_PTR() on failure 2011-07-17 23:22:02 -04:00
debugfs debugfs: move to new strtobool 2011-05-19 16:55:28 +09:30
devpts
dlm Merge branch 'for-3.1' of git://linux-nfs.org/~bfields/linux 2011-07-25 22:49:19 -07:00
ecryptfs Ecryptfs: Add mount option to check uid of device being mounted = expect uid 2011-08-09 23:29:01 -05:00
efs make d_splice_alias(ERR_PTR(err), dentry) = ERR_PTR(err) 2011-07-20 01:44:26 -04:00
exofs Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd 2011-08-06 22:56:03 -07:00
exportfs
ext2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-08-01 13:48:31 -10:00
ext3 ext3: Properly count journal credits for long symlinks 2011-08-11 17:23:40 -07:00
ext4 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2011-08-21 06:59:41 -07:00
fat Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6 2011-08-18 14:16:13 -07:00
freevxfs treewide: fix a few typos in comments 2011-05-10 10:16:21 +02:00
fscache FS-Cache: Fix __fscache_uncache_all_inode_pages()'s outer loop 2011-07-21 10:59:16 -07:00
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse 2011-08-24 09:14:42 -07:00
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-08-01 13:48:31 -10:00
hfs fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers 2011-07-20 20:47:59 -04:00
hfsplus Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-07-22 19:02:39 -07:00
hostfs fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers 2011-07-20 20:47:59 -04:00
hpfs fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers 2011-07-20 20:47:59 -04:00
hppfs hppfs: missing include 2011-07-27 22:21:58 -04:00
hugetlbfs lockdep: Add helper function for dir vs file i_mutex annotation 2011-08-25 10:50:18 -07:00
isofs isofs: Remove global fs lock 2011-07-22 19:42:12 -04:00
jbd jbd: Use WRITE_SYNC in journal checkpoint. 2011-06-28 00:06:41 +02:00
jbd2 jbd2: remove jbd2_dev_to_name() from jbd2 tracepoints 2011-07-10 22:05:08 -04:00
jffs2 switch posix_acl_equiv_mode() to umode_t * 2011-08-01 02:10:06 -04:00
jfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shaggy/jfs-2.6 2011-08-15 08:40:24 -07:00
lockd Merge branch 'nfs-for-3.1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs 2011-07-27 13:23:02 -07:00
logfs fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers 2011-07-20 20:47:59 -04:00
minix minix_getattr(): don't bother with ->d_parent 2011-07-20 20:47:53 -04:00
ncpfs fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers 2011-07-20 20:47:59 -04:00
nfs Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/linux-nfs 2011-08-18 22:47:13 -07:00
nfs_common
nfsd Merge branch 'for-3.1' of git://linux-nfs.org/~bfields/linux 2011-07-25 22:49:19 -07:00
nilfs2 fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers 2011-07-20 20:47:59 -04:00
nls
notify atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
ntfs atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
ocfs2 switch posix_acl_equiv_mode() to umode_t * 2011-08-01 02:10:06 -04:00
omfs omfs: fix (mode & S_IFDIR) abuse 2011-07-26 13:05:28 -04:00
openpromfs
partitions Merge branch 'for-linus' into for-3.1/core 2011-07-01 16:17:13 +02:00
proc vfs: show O_CLOEXE bit properly in /proc/<pid>/fdinfo/<fd> files 2011-08-06 11:51:33 -07:00
pstore pstore: Allow the user to explicitly choose a backend 2011-07-22 16:14:39 -07:00
qnx4
quota vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
ramfs
reiserfs switch posix_acl_equiv_mode() to umode_t * 2011-08-01 02:10:06 -04:00
romfs romfs: fix romfs_get_unmapped_area() argument check 2011-06-27 18:00:12 -07:00
squashfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus 2011-07-25 22:50:35 -07:00
sysfs ->permission() sanitizing: don't pass flags to ->permission() 2011-07-20 01:43:24 -04:00
sysv sysv: remove unnecessary dentry_unhash from rmdir, dir rename 2011-05-28 01:02:50 -04:00
ubifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-07-22 19:02:39 -07:00
udf switch udf_ioctl() to inode_permission() 2011-07-20 01:43:07 -04:00
ufs make d_splice_alias(ERR_PTR(err), dentry) = ERR_PTR(err) 2011-07-20 01:44:26 -04:00
xfs xfs: fix tracing builds inside the source tree 2011-08-22 16:37:24 -05:00
Kconfig tmpfs: expand "help" to explain value of TMPFS_POSIX_ACL 2011-08-03 14:25:25 -10:00
Kconfig.binfmt
Makefile nfsd: Remove deprecated nfsctl system call and related code. 2011-07-15 18:58:42 -04:00
aio.c
anon_inodes.c vfs: dont chain pipe/anon/socket on superblock s_inodes list 2011-07-26 12:57:09 -04:00
attr.c fs: move inode_dio_wait calls into ->setattr 2011-07-20 20:47:47 -04:00
bad_inode.c fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers 2011-07-20 20:47:59 -04:00
binfmt_aout.c
binfmt_elf.c consolidate BINPRM_FLAGS_ENFORCE_NONDUMP handling 2011-07-20 01:43:10 -04:00
binfmt_elf_fdpic.c consolidate BINPRM_FLAGS_ENFORCE_NONDUMP handling 2011-07-20 01:43:10 -04:00
binfmt_em86.c
binfmt_flat.c CRED: Fix load_flat_shared_library() to initialise bprm correctly 2011-05-03 10:10:51 +10:00
binfmt_misc.c consolidate BINPRM_FLAGS_ENFORCE_NONDUMP handling 2011-07-20 01:43:10 -04:00
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c block: improve the bio_add_page() and bio_add_pc_page() descriptions 2011-05-28 14:44:46 +02:00
block_dev.c fix block device fallout from ->fsync() changes 2011-08-01 21:33:47 -04:00
buffer.c vfs: Fix data corruption after failed write in __block_write_begin() 2011-06-16 11:44:46 -04:00
char_dev.c
compat.c nfsd: Remove deprecated nfsctl system call and related code. 2011-07-15 18:58:42 -04:00
compat_binfmt_elf.c
compat_ioctl.c compat_ioctl: add compat handler for PPPIOCGL2TPSTATS 2011-08-07 22:24:41 -07:00
dcache.c vfs: renumber DCACHE_xyz flags, remove some stale ones 2011-08-06 22:52:40 -07:00
dcookies.c oprofile, dcookies: Fix possible circular locking dependency 2011-05-31 16:33:35 +02:00
direct-io.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
drop_caches.c vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
eventfd.c
eventpoll.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
exec.c move RLIMIT_NPROC check from set_user() to do_execve_common() 2011-08-11 11:24:42 -07:00
fcntl.c
fhandle.c
fifo.c
file.c
file_table.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
filesystems.c
fs-writeback.c don't busy retry the inode on failed grab_super_passive() 2011-07-31 22:52:08 +08:00
fs_struct.c
generic_acl.c switch posix_acl_equiv_mode() to umode_t * 2011-08-01 02:10:06 -04:00
inode.c lockdep: Add helper function for dir vs file i_mutex annotation 2011-08-25 10:50:18 -07:00
internal.h superblock: move pin_sb_for_writeback() to fs/super.c 2011-07-20 01:44:38 -04:00
ioctl.c
ioprio.c
libfs.c fix IN_DELETE_SELF on overwriting rename() on ramfs et.al. 2011-07-22 19:42:11 -04:00
locks.c locks: rename lock-manager ops 2011-07-20 20:23:19 -04:00
mbcache.c vmscan: change shrinker API by passing shrink_control struct 2011-05-25 08:39:26 -07:00
mpage.c mm/fs: add hooks to support cleancache 2011-05-26 10:01:43 -06:00
namei.c vfs: rename 'do_follow_link' to 'should_follow_link' 2011-08-07 13:42:25 -07:00
namespace.c VFS : mount lock scalability for internal mounts 2011-07-24 10:08:32 -04:00
no-block.c
open.c merge fchmod() and fchmodat() guts, kill ancient broken kludge 2011-07-26 15:07:43 -04:00
pipe.c vfs: dont chain pipe/anon/socket on superblock s_inodes list 2011-07-26 12:57:09 -04:00
pnode.c
pnode.h
posix_acl.c switch posix_acl_chmod() to umode_t 2011-08-01 02:10:32 -04:00
read_write.c fs: add missing unlock in default_llseek() 2011-07-26 12:57:09 -04:00
read_write.h
readdir.c
select.c
seq_file.c
signalfd.c
splice.c tmpfs: clone shmem_file_splice_read() 2011-07-25 20:57:11 -07:00
stack.c mm: a few small updates for radix-swap 2011-08-03 14:25:24 -10:00
stat.c vfs: optimize inode cache access patterns 2011-08-06 22:53:23 -07:00
statfs.c
super.c Merge branch 'for-3.1/core' of git://git.kernel.dk/linux-block 2011-07-25 10:33:36 -07:00
sync.c fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers 2011-07-20 20:47:59 -04:00
timerfd.c timerfd: Fix wakeup of processes when timer is cancelled on clock change 2011-06-14 11:46:14 +02:00
utimes.c
xattr.c Cache xattr security drop check for write v2 2011-05-28 12:02:09 -04:00
xattr_acl.c