Linus Torvalds d8e464ecc1 vfs: mark pipes and sockets as stream-like file descriptors ... In commit 3975b097e5 ("convert stream-like files -> stream_open, even if they use noop_llseek") Kirill used a coccinelle script to change "nonseekable_open()" to "stream_open()", which changed the trivial cases of stream-like file descriptors to the new model with FMODE_STREAM. However, the two big cases - sockets and pipes - don't actually have that trivial pattern at all, and were thus never converted to FMODE_STREAM even though it makes lots of sense to do so. That's particularly true when looking forward to the next change: getting rid of FMODE_ATOMIC_POS entirely, and just using FMODE_STREAM to decide whether f_pos updates are needed or not. And if they are, we'll always do them atomically. This came up because KCSAN (correctly) noted that the non-locked f_pos updates are data races: they are clearly benign for the case where we don't care, but it would be good to just not have that issue exist at all. Note that the reason we used FMODE_ATOMIC_POS originally is that only doing it for the minimal required case is "safer" in that it's possible that the f_pos locking can cause unnecessary serialization across the whole write() call. And in the worst case, that kind of serialization can cause deadlock issues: think writers that need readers to empty the state using the same file descriptor. [ Note that the locking is per-file descriptor - because it protects "f_pos", which is obviously per-file descriptor - so it only affects cases where you literally use the same file descriptor to both read and write. So a regular pipe that has separate reading and writing file descriptors doesn't really have this situation even though it's the obvious case of "reader empties what a bit writer concurrently fills" But we want to make pipes as being stream-line anyway, because we don't want the unnecessary overhead of locking, and because a named pipe can be (ab-)used by reading and writing to the same file descriptor. ] There are likely a lot of other cases that might want FMODE_STREAM, and looking for ".llseek = no_llseek" users and other cases that don't have an lseek file operation at all and making them use "stream_open()" might be a good idea. But pipes and sockets are likely to be the two main cases. Cc: Kirill Smelkov <kirr@nexedi.com> Cc: Eic Dumazet <edumazet@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Marco Elver <elver@google.com> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Paul McKenney <paulmck@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2019-11-25 09:12:11 -08:00
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9p
adfs
affs
afs	afs: Fix large file support	2019-11-22 14:19:26 -08:00
autofs
befs
bfs
btrfs	for-5.4-rc7-tag	2019-11-13 12:06:10 -08:00
cachefiles
ceph	ceph: increment/decrement dio counter on async requests	2019-11-14 18:44:51 +01:00
cifs	SMB3: Fix persistent handles reconnect	2019-11-06 21:32:18 -06:00
coda
configfs	configfs: calculate the depth of parent item	2019-11-06 18:36:01 +01:00
cramfs	cramfs: fix usage on non-MTD device	2019-11-23 21:44:49 -05:00
crypto
debugfs
devpts
dlm
ecryptfs	ecryptfs_lookup_interpose(): lower_dentry->d_parent is not stable either	2019-11-10 11:57:45 -05:00
efivarfs
efs
erofs
exportfs	exportfs_decode_fh(): negative pinned may become positive without the parent locked	2019-11-10 11:56:05 -05:00
ext2
ext4
f2fs
fat
freevxfs
fscache
fuse
gfs2	gfs2: Fix initialisation of args for remount	2019-10-30 12:16:53 +01:00
hfs
hfsplus
hostfs
hpfs
hugetlbfs
iomap
isofs
jbd2
jffs2
jfs
kernfs
lockd
minix
nfs	NFS: Fix an RCU lock leak in nfs4_refresh_delegation_stateid()	2019-11-01 11:03:56 -04:00
nfs_common
nfsd
nilfs2
nls
notify
ntfs
ocfs2	Revert "fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()"	2019-11-22 09:11:18 -08:00
omfs
openpromfs
orangefs
overlayfs
proc
pstore
qnx4
qnx6
quota
ramfs
reiserfs
romfs
squashfs
sysfs
sysv
tracefs
ubifs
udf
ufs
unicode
verity
xfs
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
block_dev.c
buffer.c
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c
compat.c
coredump.c
d_path.c
dax.c
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fhandle.c
file_table.c
file.c
filesystems.c
fs_context.c
fs_parser.c
fs_pin.c
fs_struct.c
fs_types.c
fs-writeback.c	cgroup,writeback: don't switch wbs immediately on dead wbs if the memcg is dead	2019-11-08 13:37:24 -07:00
fsopen.c
inode.c
internal.h
io_uring.c	io_uring: ensure registered buffer import returns the IO length	2019-11-13 16:15:14 -07:00
ioctl.c
Kconfig
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mount.h
mpage.c
namei.c
namespace.c
no-block.c
nsfs.c
open.c
pipe.c	vfs: mark pipes and sockets as stream-like file descriptors	2019-11-25 09:12:11 -08:00
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