linux-sg2042/fs
Benjamin Coddington 9d5b86ac13 fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks
Since commit c69899a17c "NFSv4: Update of VFS byte range lock must be
atomic with the stateid update", NFSv4 has been inserting locks in rpciod
worker context.  The result is that the file_lock's fl_nspid is the
kworker's pid instead of the original userspace pid.

The fl_nspid is only used to represent the namespaced virtual pid number
when displaying locks or returning from F_GETLK.  There's no reason to set
it for every inserted lock, since we can usually just look it up from
fl_pid.  So, instead of looking up and holding struct pid for every lock,
let's just look up the virtual pid number from fl_pid when it is needed.
That means we can remove fl_nspid entirely.

The translaton and presentation of fl_pid should handle the following four
cases:

1 - F_GETLK on a remote file with a remote lock:
    In this case, the filesystem should determine the l_pid to return here.
    Filesystems should indicate that the fl_pid represents a non-local pid
    value that should not be translated by returning an fl_pid <= 0.

2 - F_GETLK on a local file with a remote lock:
    This should be the l_pid of the lock manager process, and translated.

3 - F_GETLK on a remote file with a local lock, and
4 - F_GETLK on a local file with a local lock:
    These should be the translated l_pid of the local locking process.

Fuse was already doing the correct thing by translating the pid into the
caller's namespace.  With this change we must update fuse to translate
to init's pid namespace, so that the locks API can then translate from
init's pid namespace into the pid namespace of the caller.

With this change, the locks API will expect that if a filesystem returns
a remote pid as opposed to a local pid for F_GETLK, that remote pid will
be <= 0.  This signifies that the pid is remote, and the locks API will
forego translating that pid into the pid namespace of the local calling
process.

Finally, we convert remote filesystems to present remote pids using
negative numbers. Have lustre, 9p, ceph, cifs, and dlm negate the remote
pid returned for F_GETLK lock requests.

Since local pids will never be larger than PID_MAX_LIMIT (which is
currently defined as <= 4 million), but pid_t is an unsigned int, we
should have plenty of room to represent remote pids with negative
numbers if we assume that remote pid numbers are similarly limited.

If this is not the case, then we run the risk of having a remote pid
returned for which there is also a corresponding local pid.  This is a
problem we have now, but this patch should reduce the chances of that
occurring, while also returning those remote pid numbers, for whatever
that may be worth.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-16 10:28:22 -04:00
..
9p fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks 2017-07-16 10:28:22 -04:00
adfs
affs affs: Implement show_options 2017-07-11 06:06:17 -04:00
afs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
autofs4 Fix up over-eager 'wait_queue_t' renaming 2017-07-10 11:40:19 -07:00
befs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
bfs bfs: fix sanity checks for empty files 2017-07-12 16:26:00 -07:00
btrfs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
cachefiles sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming 2017-06-20 12:19:14 +02:00
ceph fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks 2017-07-16 10:28:22 -04:00
cifs fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks 2017-07-16 10:28:22 -04:00
coda fs: implement vfs_iter_write using do_iter_write 2017-06-29 17:49:23 -04:00
configfs configfs: Introduce config_item_get_unless_zero() 2017-06-12 13:20:20 +02:00
cramfs
crypto The first major feature for ext4 this merge window is the largedir 2017-07-09 09:31:22 -07:00
debugfs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
devpts
dlm fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks 2017-07-16 10:28:22 -04:00
ecryptfs ecryptfs: Convert to separately allocated bdi 2017-04-20 12:09:55 -06:00
efivarfs VFS: Kill off s_options and helpers 2017-07-11 06:09:21 -04:00
efs
exofs mm: drop "wait" parameter from write_one_page() 2017-07-05 18:44:22 -04:00
exportfs Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-03-03 11:38:56 -08:00
ext2 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2017-07-13 13:53:54 -07:00
ext4 The first major feature for ext4 this merge window is the largedir 2017-07-09 09:31:22 -07:00
f2fs for-f2fs-4.13 2017-07-10 14:29:45 -07:00
fat fat: fix using uninitialized fields of fat_inode/fsinfo_inode 2017-03-09 17:01:10 -08:00
freevxfs
fscache KEYS: Differentiate uses of rcu_dereference_key() and user_key_payload() 2017-03-02 10:09:00 +11:00
fuse fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks 2017-07-16 10:28:22 -04:00
gfs2 Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
hfs fs: semove set but not checked AOP_FLAG_UNINTERRUPTIBLE flag 2017-05-08 17:15:14 -07:00
hfsplus fs: semove set but not checked AOP_FLAG_UNINTERRUPTIBLE flag 2017-05-08 17:15:14 -07:00
hostfs
hpfs sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
hugetlbfs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
isofs isofs: Fix isofs_show_options() 2017-07-13 12:30:43 -04:00
jbd2 Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
jffs2 jffs2: fix spelling mistake: "requestied" -> "requested" 2017-04-19 11:35:55 -07:00
jfs Writeback error handling fixes (pile #1) 2017-07-07 18:39:15 -07:00
kernfs kernfs: Check KERNFS_HAS_RELEASE before calling kernfs_release_file() 2017-03-17 10:25:59 +09:00
lockd sunrpc: mark all struct svc_version instances as const 2017-07-13 15:58:03 -04:00
minix Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
ncpfs mm: per-cgroup memory reclaim stats 2017-07-06 16:24:35 -07:00
nfs NFS client updates for Linux 4.13 2017-07-13 14:35:37 -07:00
nfs_common
nfsd Chuck's RDMA update overhauls the "call receive" side of the 2017-07-13 13:56:24 -07:00
nilfs2 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-03 13:08:04 -07:00
nls
notify dentry name snapshots 2017-07-07 20:09:10 -04:00
ntfs ntfs: Use ERR_CAST() to avoid cross-structure cast 2017-05-28 10:11:48 -07:00
ocfs2 ocfs2: constify attribute_group structures 2017-07-06 16:24:30 -07:00
omfs omfs: Implement show_options 2017-07-06 03:31:46 -04:00
openpromfs
orangefs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
overlayfs ovl: mark parent impure and restore timestamp on ovl_link_up() 2017-07-04 22:08:15 +02:00
proc fault-inject: add /proc/<pid>/fail-nth 2017-07-14 15:05:13 -07:00
pstore Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
qnx4
qnx6
quota quota: add get_inode_usage callback to transfer multi-inode charges 2017-06-22 11:46:48 -04:00
ramfs ramfs: Implement show_options 2017-07-06 03:31:46 -04:00
reiserfs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
romfs
squashfs fs/pstore: fs/squashfs: change usage of LZ4 to work with new LZ4 version 2017-02-24 17:46:57 -08:00
sysfs sysfs: be careful of error returns from ops->show() 2017-04-08 17:33:32 +02:00
sysv mm: drop "wait" parameter from write_one_page() 2017-07-05 18:44:22 -04:00
tracefs VFS: Don't use save/replace_mount_options if not using generic_show_options 2017-07-06 03:31:46 -04:00
ubifs ubifs: Set double hash cookie also for RENAME_EXCHANGE 2017-07-14 22:50:57 +02:00
udf udf: Convert udf_disk_stamp_to_time() to use mktime64() 2017-06-14 11:21:02 +02:00
ufs Writeback error handling fixes (pile #1) 2017-07-07 18:39:15 -07:00
xfs Changes since last update: 2017-07-14 22:57:32 -07:00
Kconfig fs/Kconfig: kill CONFIG_PERCPU_RWSEM some more 2017-07-12 16:26:00 -07:00
Kconfig.binfmt
Makefile
aio.c fs: add O_DIRECT and aio support for sending down write life time hints 2017-06-27 12:05:36 -06:00
anon_inodes.c
attr.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
bad_inode.c statx: Add a system call to make enhanced file info available 2017-03-02 20:51:15 -05:00
binfmt_aout.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
binfmt_elf.c binfmt_elf: safely increment argv pointers 2017-07-10 16:32:36 -07:00
binfmt_elf_fdpic.c sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h> 2017-03-02 08:42:39 +01:00
binfmt_em86.c
binfmt_flat.c binfmt_flat: flat_{get,put}_addr_from_rp() should be able to fail 2017-07-03 18:44:02 -04:00
binfmt_misc.c fs: constify tree_descr arrays passed to simple_fill_super() 2017-04-26 23:54:06 -04:00
binfmt_script.c
block_dev.c Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
buffer.c fs/buffer.c: make bh_lru_install() more efficient 2017-07-10 16:32:30 -07:00
char_dev.c chardev: add helper function to register char devs with a struct device 2017-03-21 06:44:32 +01:00
compat.c fs/compat.c: trim unused includes 2017-04-17 12:52:27 -04:00
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'work.__copy_in_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:15:02 -07:00
coredump.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
dax.c Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
dcache.c Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
dcookies.c
direct-io.c fs: add O_DIRECT and aio support for sending down write life time hints 2017-06-27 12:05:36 -06:00
drop_caches.c
eventfd.c There has been a fair amount of activity in the docs tree this time 2017-07-03 21:13:25 -07:00
eventpoll.c kcmp: fs/epoll: wrap kcmp code with CONFIG_CHECKPOINT_RESTORE 2017-07-12 16:26:01 -07:00
exec.c exec: Limit arg stack to at most 75% of _STK_LIM 2017-07-07 20:05:08 -07:00
fcntl.c vfs: fix flock compat thinko 2017-07-07 13:48:18 -07:00
fhandle.c fhandle: move compat syscalls from compat.c 2017-04-17 12:52:26 -04:00
file.c fs/file.c: replace alloc_fdmem() with kvmalloc() alternative 2017-07-06 16:24:30 -07:00
file_table.c fs: new infrastructure for writeback error handling and reporting 2017-07-06 07:02:25 -04:00
filesystems.c Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
fs-writeback.c writeback: rework wb_[dec|inc]_stat family of functions 2017-07-12 16:26:05 -07:00
fs_pin.c sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming 2017-06-20 12:19:14 +02:00
fs_struct.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h> 2017-03-02 08:42:35 +01:00
inode.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
internal.h Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-05-09 09:12:53 -07:00
ioctl.c sched/headers: Prepare for the reduction of <linux/sched.h>'s signal API dependency 2017-03-02 08:42:37 +01:00
iomap.c Changes since last update: 2017-07-14 22:57:32 -07:00
libfs.c fs: convert __generic_file_fsync to use errseq_t based reporting 2017-07-06 07:02:29 -04:00
locks.c fs/locks: Remove fl_nspid and use fs-specific l_pid for remote locks 2017-07-16 10:28:22 -04:00
mbcache.c ext4: xattr inode deduplication 2017-06-22 11:44:55 -04:00
mount.h mnt: In propgate_umount handle visiting mounts in any order 2017-05-23 08:41:16 -05:00
mpage.c There has been a fair amount of activity in the docs tree this time 2017-07-03 21:13:25 -07:00
namei.c Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
namespace.c Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
no-block.c
nsfs.c VFS: Provide empty name qstr 2017-07-06 03:27:09 -04:00
open.c Writeback error handling fixes (pile #2) 2017-07-07 19:38:17 -07:00
pipe.c VFS: Provide empty name qstr 2017-07-06 03:27:09 -04:00
pnode.c mnt: Make propagate_umount less slow for overlapping mount propagation trees 2017-05-23 08:41:17 -05:00
pnode.h
posix_acl.c sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h> 2017-03-02 08:42:31 +01:00
proc_namespace.c sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
read_write.c Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-07 21:48:15 -07:00
readdir.c readdir: move compat syscalls from compat.c 2017-04-17 12:52:24 -04:00
select.c Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 20:57:13 -07:00
seq_file.c mm: introduce kv[mz]alloc helpers 2017-05-08 17:15:12 -07:00
signalfd.c sched/wait: Rename wait_queue_t => wait_queue_entry_t 2017-06-20 12:18:27 +02:00
splice.c fs: implement vfs_iter_write using do_iter_write 2017-06-29 17:49:23 -04:00
stack.c
stat.c ufs: restore maintaining ->i_blocks 2017-06-09 16:28:01 -04:00
statfs.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-08 10:50:54 -07:00
super.c VFS: Kill off s_options and helpers 2017-07-11 06:09:21 -04:00
sync.c fs: remove call_fsync helper function 2017-07-05 18:44:23 -04:00
timerfd.c timerfd: Use get_itimerspec64() and put_itimerspec64() 2017-06-30 04:14:38 -04:00
userfaultfd.c mm/hugetlb: add size parameter to huge_pte_offset() 2017-07-06 16:24:34 -07:00
utimes.c utimes: move compat syscalls from compat.c 2017-04-17 12:52:23 -04:00
xattr.c treewide: use kv[mz]alloc* rather than opencoded variants 2017-05-08 17:15:13 -07:00