linux/fs
Trond Myklebust daf3761c9f namei: results of d_is_negative() should be checked after dentry revalidation
Leandro Awa writes:
 "After switching to version 4.1.6, our parallelized and distributed
  workflows now fail consistently with errors of the form:

  T34: ./regex.c:39:22: error: config.h: No such file or directory

  From our 'git bisect' testing, the following commit appears to be the
  possible cause of the behavior we've been seeing: commit 766c4cbfacd8"

Al Viro says:
 "What happens is that 766c4cbfac got the things subtly wrong.

  We used to treat d_is_negative() after lookup_fast() as "fall with
  ENOENT".  That was wrong - checking ->d_flags outside of ->d_seq
  protection is unreliable and failing with hard error on what should've
  fallen back to non-RCU pathname resolution is a bug.

  Unfortunately, we'd pulled the test too far up and ran afoul of
  another kind of staleness.  The dentry might have been absolutely
  stable from the RCU point of view (and we might be on UP, etc), but
  stale from the remote fs point of view.  If ->d_revalidate() returns
  "it's actually stale", dentry gets thrown away and the original code
  wouldn't even have looked at its ->d_flags.

  What we need is to check ->d_flags where 766c4cbfac does (prior to
  ->d_seq validation) but only use the result in cases where we do not
  discard this dentry outright"

Reported-by: Leandro Awa <lawa@nvidia.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=104911
Fixes: 766c4cbfac ("namei: d_is_negative() should be checked...")
Tested-by: Leandro Awa <lawa@nvidia.com>
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-10 10:17:27 -07:00
..
9p
adfs
affs
afs
autofs4
befs
bfs
btrfs Merge branch 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2015-10-09 16:39:35 -07:00
cachefiles
ceph
cifs [CIFS] Update cifs version number 2015-10-03 16:54:17 -05:00
coda
configfs
cramfs
debugfs
devpts
dlm
ecryptfs
efivarfs
efs
exofs
exportfs
ext2
ext4
f2fs
fat
freevxfs
fscache
fuse
gfs2
hfs
hfsplus
hostfs
hpfs
hugetlbfs
isofs
jbd2
jffs2
jfs
kernfs
lockd
logfs
minix
ncpfs
nfs NFS: Fix a tracepoint NULL-pointer dereference 2015-10-06 18:56:25 -04:00
nfs_common
nfsd
nilfs2
nls
notify
ntfs
ocfs2
omfs
openpromfs
overlayfs
proc
pstore
qnx4
qnx6
quota
ramfs
reiserfs
romfs
squashfs
sysfs
sysv
tracefs
ubifs UBIFS: Kill unneeded locking in ubifs_init_security 2015-09-29 12:45:42 +02:00
udf
ufs
xfs
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf.c
binfmt_elf_fdpic.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
block_dev.c
buffer.c
char_dev.c
compat.c
compat_binfmt_elf.c
compat_ioctl.c
coredump.c
dax.c dax: fix NULL pointer in __dax_pmd_fault() 2015-10-01 21:42:35 -04:00
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fhandle.c
file.c
file_table.c
filesystems.c
fs-writeback.c
fs_pin.c
fs_struct.c
inode.c
internal.h
ioctl.c
Kconfig
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mount.h
mpage.c
namei.c namei: results of d_is_negative() should be checked after dentry revalidation 2015-10-10 10:17:27 -07:00
namespace.c
no-block.c
nsfs.c
open.c
pipe.c
pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c
readdir.c
select.c
seq_file.c
signalfd.c
splice.c
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c
userfaultfd.c
utimes.c
xattr.c