linux/fs
Tejun Heo 9b2db6e189 sysfs: bail early from kernfs_file_mmap() to avoid spurious lockdep warning
This is v3.14 fix for the same issue that a8b1474442 ("sysfs: give
different locking key to regular and bin files") addresses for v3.13.
Due to the extensive kernfs reorganization in v3.14 branch, the same
fix couldn't be ported as-is.  The v3.13 fix was ignored while merging
it into v3.14 branch.

027a485d12 ("sysfs: use a separate locking class for open files
depending on mmap") assigned different lockdep key to
sysfs_open_file->mutex depending on whether the file implements mmap
or not in an attempt to avoid spurious lockdep warning caused by
merging of regular and bin file paths.

While this restored some of the original behavior of using different
locks (at least lockdep is concerned) for the different clases of
files.  The restoration wasn't full because now the lockdep key
assignment depends on whether the file has mmap or not instead of
whether it's a regular file or not.

This means that bin files which don't implement mmap will get assigned
the same lockdep class as regular files.  This is problematic because
file_operations for bin files still implements the mmap file operation
and checking whether the sysfs file actually implements mmap happens
in the file operation after grabbing @sysfs_open_file->mutex.  We
still end up adding locking dependency from mmap locking to
sysfs_open_file->mutex to the regular file mutex which triggers
spurious circular locking warning.

For v3.13, a8b1474442 ("sysfs: give different locking key to regular
and bin files") fixed it by giving sysfs_open_file->mutex different
lockdep keys depending on whether the file is regular or bin instead
of whether mmap exists or not; however, due to the way sysfs is now
layered behind kernfs, this approach is no longer viable.  kernfs can
tell whether a sysfs node has mmap implemented or not but can't tell
whether a bin file from a regular one.

This patch updates kernfs such that kernfs_file_mmap() checks
SYSFS_FLAG_HAS_MMAP and bail before grabbing sysfs_open_file->mutex so
that it doesn't add spurious locking dependency from mmap to
sysfs_open_file->mutex and changes sysfs so that it specifies
kernfs_ops->mmap iff the sysfs file implements mmap.  Combined, this
ensures that sysfs_open_file->mutex is grabbed under mmap path iff the
sysfs file actually implements mmap.  As sysfs_open_file->mutex is
already given a different lockdep key if mmap is implemented, this
removes the spurious locking dependency.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Dave Jones <davej@redhat.com>
Link: http://lkml.kernel.org/g/20131203184324.GA11320@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-10 21:33:31 -08:00
..
9p consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
adfs adfs: delayed freeing of sbi 2013-10-24 23:43:27 -04:00
affs remove obsolete references to powertweak 2013-11-27 20:34:32 -08:00
afs Merge branch 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into linux-next 2013-10-28 19:36:46 -04:00
autofs4 autofs4: make freeing sbi rcu-delayed 2013-10-24 23:43:27 -04:00
befs befs: split symlink iops in two - for short and long symlinks resp. 2013-10-24 23:34:50 -04:00
bfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
btrfs Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2013-12-05 15:33:27 -08:00
cachefiles Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
ceph Merge branch 'for-linus-bugs' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2013-11-26 18:02:46 -08:00
cifs [CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload 2013-11-25 09:50:31 -06:00
coda coda_revalidate_inode(): switch to passing inode... 2013-11-09 00:16:21 -05:00
configfs configfs: fix race between dentry put and lookup 2013-11-21 16:42:27 -08:00
cramfs cramfs: mark as obsolete 2013-11-13 12:09:12 +09:00
debugfs debugfs: use list_next_entry() in debugfs_remove_recursive() 2013-11-13 12:09:24 +09:00
devpts devpts: plug the memory leak in kill_sb 2013-11-13 12:09:36 +09:00
dlm genetlink: only pass array to genl_register_family_with_ops() 2013-11-19 16:39:05 -05:00
ecryptfs Quiet static checkers by removing unneeded conditionals 2013-11-22 10:58:14 -08:00
efivarfs consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
efs efs: iget_locked() doesn't return an ERR_PTR() 2013-08-24 12:10:22 -04:00
exofs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
exportfs exportfs: fix quadratic behavior in filehandle lookup 2013-11-09 00:16:38 -05:00
ext2 ext2: Fix fs corruption in ext2_get_xip_mem() 2013-11-05 11:26:47 +01:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2013-11-13 15:25:47 +09:00
ext4 Ext4 updates for 3.13. Mostly bug fixes and cleanups. 2013-11-14 17:19:58 +09:00
f2fs f2fs: issue more large discard command 2013-11-11 09:36:32 +09:00
fat fat: rcu-delay unloading nls and freeing sbi 2013-10-24 23:43:28 -04:00
freevxfs [readdir] convert freevxfs 2013-06-29 12:56:53 +04:00
fscache Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block 2013-11-14 12:08:14 +09:00
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
gfs2 GFS2: Fix ref count bug relating to atomic_open 2013-11-21 18:47:57 +00:00
hfs fs/hfs/btree.h: remove duplicate defines 2013-11-13 12:09:32 +09:00
hfsplus block: submit_bio_wait() conversions 2013-11-24 16:33:41 -07:00
hostfs consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
hpfs locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
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 isofs: don't pass dentry to isofs_hash{i,}_common() 2013-10-24 23:34:59 -04:00
jbd jbd: Revert "jbd: remove dependency on __GFP_NOFAIL" 2013-10-31 20:37:15 +01:00
jbd2 jbd2: Fix endian mixing problems in the checksumming code 2013-08-28 14:59:58 -04:00
jffs2 jffs2: do not support the MLC nand 2013-10-27 16:27:07 -07:00
jfs Just a patch to fix an oops in an error path. 2013-10-22 09:01:11 +01:00
kernfs sysfs: bail early from kernfs_file_mmap() to avoid spurious lockdep warning 2013-12-10 21:33:31 -08:00
lockd LOCKD: Don't call utsname()->nodename from nlmclnt_setlockargs 2013-08-05 15:03:46 -04:00
logfs block: submit_bio_wait() conversions 2013-11-24 16:33:41 -07:00
minix fs/minix: Drop dependency on H8300 2013-09-16 18:20:25 -07:00
ncpfs ncpfs: rcu-delay unload_nls() and freeing ncp_server 2013-10-24 23:43:28 -04:00
nfs NFS client bugfixes 2013-12-05 13:05:48 -08:00
nfs_common
nfsd nfsd4: fix xdr decoding of large non-write compounds 2013-11-19 18:06:54 -05:00
nilfs2 nilfs2: fix issue with race condition of competition between segments for dirty blocks 2013-09-30 14:31:02 -07:00
nls
notify fsnotify: update comments concerning locking scheme 2013-07-09 10:33:20 -07:00
ntfs iget/iget5: don't bother with ->i_lock until we find a match 2013-11-09 00:16:31 -05:00
ocfs2 tree-wide: use reinit_completion instead of INIT_COMPLETION 2013-11-15 09:32:21 +09:00
omfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
openpromfs [readdir] convert openpromfs 2013-06-29 12:56:32 +04:00
proc Merge git://git.infradead.org/users/eparis/audit 2013-11-21 19:18:14 -08:00
pstore pstore: Remove the messages related to compression failure 2013-09-16 09:28:29 -07:00
qnx4 qnx4: i_sb is never NULL 2013-11-09 00:16:32 -05:00
qnx6 [readdir] convert qnx6 2013-06-29 12:56:39 +04:00
quota genetlink: make multicast groups const, prevent abuse 2013-11-19 16:39:06 -05:00
ramfs initmpfs: move rootfs code from fs/ramfs/ to init/ 2013-09-11 15:59:37 -07:00
reiserfs reiserfs: fix race with flush_used_journal_lists and flush_journal_list 2013-09-24 11:24:21 +02:00
romfs [readdir] convert romfs 2013-06-29 12:56:29 +04:00
squashfs Squashfs: fix failure to unlock pages on decompress error 2013-11-24 01:02:50 +00:00
sysfs sysfs: bail early from kernfs_file_mmap() to avoid spurious lockdep warning 2013-12-10 21:33:31 -08:00
sysv sysv: Add forgotten superblock lock init for v7 fs 2013-09-29 22:02:02 -04:00
ubifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
udf udf: fix for pathetic mount times in case of invalid file system 2013-10-18 22:39:07 +02:00
ufs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
xfs xfs: update #2 for v3.13-rc1 2013-11-22 08:37:47 -08:00
aio.c Merge git://git.kvack.org/~bcrl/aio-next 2013-12-06 08:32:59 -08:00
anon_inodes.c ... and kill anon_inode_getfile_private() 2013-11-09 00:16:28 -05:00
attr.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
bad_inode.c [readdir] ->readdir() is gone 2013-06-29 12:57:04 +04:00
binfmt_aout.c dump_skip(): dump_seek() replacement taking coredump_params 2013-11-09 00:16:26 -05:00
binfmt_elf_fdpic.c elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo) 2013-11-09 00:16:30 -05:00
binfmt_elf.c elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo) 2013-11-09 00:16:30 -05:00
binfmt_em86.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c Merge branch 'for-3.12/core' of git://git.kernel.dk/linux-block 2013-09-22 15:00:11 -07:00
bio.c bio: fix argument of __bio_add_page() for max_sectors > 0xffff 2013-11-18 12:31:27 -07:00
block_dev.c a trivial writeback fix 2013-09-13 23:06:40 -04:00
buffer.c fs: buffer: move allocation failure loop into the allocator 2013-10-16 21:35:53 -07:00
char_dev.c Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block 2013-11-14 12:08:14 +09:00
compat_binfmt_elf.c
compat_ioctl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
compat.c [readdir] constify ->actor 2013-06-29 12:57:05 +04:00
coredump.c dump_emit(): use __kernel_write(), not vfs_write() 2013-11-15 22:04:09 -05:00
coredump.h
dcache.c fold try_to_ascend() into the sole remaining caller 2013-11-15 22:04:17 -05:00
dcookies.c
direct-io.c direct-io: Use return from cmpxchg to decide of assignment happened 2013-09-09 10:47:42 -07:00
drop_caches.c shrinker: add node awareness 2013-09-10 18:56:31 -04:00
eventfd.c
eventpoll.c epoll: drop EPOLLWAKEUP if PM_SLEEP is disabled 2013-12-03 15:35:52 +01:00
exec.c Merge git://git.infradead.org/users/eparis/audit 2013-11-21 19:18:14 -08:00
fcntl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
fhandle.c
file_table.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
file.c
filesystems.c
fs_struct.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
fs-writeback.c Merge branch 'akpm' (patches from Andrew Morton) 2013-11-13 15:45:43 +09:00
generic_acl.c
inode.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
internal.h get rid of s_files and files_lock 2013-11-09 00:16:20 -05:00
ioctl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
locks.c locks: missing unlock on error in generic_add_lease() 2013-11-13 07:30:53 -05:00
Makefile sysfs, kernfs: add skeletons for kernfs 2013-11-27 13:28:24 -08:00
mbcache.c fs: convert fs shrinkers to new scan/count API 2013-09-10 18:56:31 -04:00
mount.h RCU'd vfsmounts 2013-11-09 00:16:19 -05:00
mpage.c
namei.c fix bogus path_put() of nd->root after some unlazy_walk() failures 2013-11-29 01:50:51 -05:00
namespace.c sysfs, kernfs: prepare mount path for kernfs 2013-11-29 18:16:08 -08:00
no-block.c
open.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
pipe.c vfs: fix subtle use-after-free of pipe_inode_info 2013-12-02 09:44:51 -08:00
pnode.c split __lookup_mnt() in two functions 2013-10-24 23:35:00 -04:00
pnode.h vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces 2013-08-26 18:42:15 -07:00
posix_acl.c
proc_namespace.c don't bother with vfsmount_lock in mounts_poll() 2013-10-24 23:34:59 -04:00
read_write.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
readdir.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
select.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
seq_file.c seq_file: always clear m->count when we free m->buf 2013-11-18 19:07:53 -08:00
signalfd.c
splice.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
stack.c
stat.c vfs: split out vfs_getattr_nosec 2013-11-09 00:16:31 -05:00
statfs.c vfs: allow O_PATH file descriptors for fstatfs() 2013-10-12 13:12:31 -07:00
super.c get rid of s_files and files_lock 2013-11-09 00:16:20 -05:00
sync.c Merge branch 'akpm' (patches from Andrew Morton) 2013-11-13 15:45:43 +09:00
timerfd.c
utimes.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
xattr_acl.c
xattr.c