linux-sg2042/fs
Jeff Layton d529ef83c3 NFS: fix the handling of NFS_INO_INVALID_DATA flag in nfs_revalidate_mapping
There is a possible race in how the nfs_invalidate_mapping function is
handled.  Currently, we go and invalidate the pages in the file and then
clear NFS_INO_INVALID_DATA.

The problem is that it's possible for a stale page to creep into the
mapping after the page was invalidated (i.e., via readahead). If another
writer comes along and sets the flag after that happens but before
invalidate_inode_pages2 returns then we could clear the flag
without the cache having been properly invalidated.

So, we must clear the flag first and then invalidate the pages. Doing
this however, opens another race:

It's possible to have two concurrent read() calls that end up in
nfs_revalidate_mapping at the same time. The first one clears the
NFS_INO_INVALID_DATA flag and then goes to call nfs_invalidate_mapping.

Just before calling that though, the other task races in, checks the
flag and finds it cleared. At that point, it trusts that the mapping is
good and gets the lock on the page, allowing the read() to be satisfied
from the cache even though the data is no longer valid.

These effects are easily manifested by running diotest3 from the LTP
test suite on NFS. That program does a series of DIO writes and buffered
reads. The operations are serialized and page-aligned but the existing
code fails the test since it occasionally allows a read to come out of
the cache incorrectly. While mixing direct and buffered I/O isn't
recommended, I believe it's possible to hit this in other ways that just
use buffered I/O, though that situation is much harder to reproduce.

The problem is that the checking/clearing of that flag and the
invalidation of the mapping really need to be atomic. Fix this by
serializing concurrent invalidations with a bitlock.

At the same time, we also need to allow other places that check
NFS_INO_INVALID_DATA to check whether we might be in the middle of
invalidating the file, so fix up a couple of places that do that
to look for the new NFS_INO_INVALIDATING flag.

Doing this requires us to be careful not to set the bitlock
unnecessarily, so this code only does that if it believes it will
be doing an invalidation.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-01-27 15:35:56 -05:00
..
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
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: fix the handling of NFS_INO_INVALID_DATA flag in nfs_revalidate_mapping 2014-01-27 15:35:56 -05:00
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 Revert "sysfs: handle duplicate removal attempts in sysfs_remove_group()" 2013-11-27 09:44:55 -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
Kconfig
Kconfig.binfmt
Makefile
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.c elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo) 2013-11-09 00:16:30 -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_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.c [readdir] constify ->actor 2013-06-29 12:57:05 +04:00
compat_binfmt_elf.c
compat_ioctl.c file->f_op is never NULL... 2013-10-24 23:34:54 -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.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
filesystems.c
fs-writeback.c Merge branch 'akpm' (patches from Andrew Morton) 2013-11-13 15:45:43 +09:00
fs_struct.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
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
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
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 RCU'd vfsmounts 2013-11-09 00:16:19 -05:00
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 timerfd: Add alarm timers 2013-05-29 12:57:34 -07:00
utimes.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
xattr.c
xattr_acl.c