Miklos Szeredi 9f6c61f96f proc/mounts: add cursor ... If mounts are deleted after a read(2) call on /proc/self/mounts (or its kin), the subsequent read(2) could miss a mount that comes after the deleted one in the list. This is because the file position is interpreted as the number mount entries from the start of the list. E.g. first read gets entries #0 to #9; the seq file index will be 10. Then entry #5 is deleted, resulting in #10 becoming #9 and #11 becoming #10, etc... The next read will continue from entry #10, and #9 is missed. Solve this by adding a cursor entry for each open instance. Taking the global namespace_sem for write seems excessive, since we are only dealing with a per-namespace list. Instead add a per-namespace spinlock and use that together with namespace_sem taken for read to protect against concurrent modification of the mount list. This may reduce parallelism of is_local_mountpoint(), but it's hardly a big contention point. We could also use RCU freeing of cursors to make traversal not need additional locks, if that turns out to be neceesary. Only move the cursor once for each read (cursor is not added on open) to minimize cacheline invalidation. When EOF is reached, the cursor is taken off the list, in order to prevent an excessive number of cursors due to inactive open file descriptors. Reported-by: Karel Zak <kzak@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>		2020-05-14 16:44:24 +02:00
..
9p	9p: read only once on O_NONBLOCK	2020-03-27 09:29:56 +00:00
adfs
affs
afs	afs: Make record checking use TASK_UNINTERRUPTIBLE when appropriate	2020-04-24 16:33:32 +01:00
autofs	LOOKUP_MOUNTPOINT: fold path_mountpointat() into path_lookupat()	2020-03-13 21:08:17 -04:00
befs
bfs
btrfs	btrfs: fix gcc-4.8 build warning for struct initializer	2020-04-30 12:17:49 +02:00
cachefiles
ceph	ceph: fix potential bad pointer deref in async dirops cb's	2020-04-13 19:33:47 +02:00
cifs	cifs: fix uninitialised lease_key in open_shroot()	2020-04-22 20:29:11 -05:00
coda
configfs
cramfs
crypto	fscrypt updates for 5.7	2020-03-31 12:58:36 -07:00
debugfs	debugfs: remove return value of debugfs_create_u32()	2020-04-17 17:08:50 +02:00
devpts
dlm
ecryptfs
efivarfs	efi: Use more granular check for availability for variable services	2020-02-23 21:59:42 +01:00
efs
erofs	erofs: handle corrupted images whose decompressed size less than it'd be	2020-03-03 23:40:52 +08:00
exfat	exfat: truncate atimes to 2s granularity	2020-04-22 20:14:06 +09:00
exportfs
ext2	ext2: fix empty body warnings when -Wextra is used	2020-03-23 13:01:37 +01:00
ext4	ext4: convert BUG_ON's to WARN_ON's in mballoc.c	2020-04-15 23:58:49 -04:00
f2fs	f2fs-for-5.7-rc1	2020-04-07 13:48:26 -07:00
fat	fat: fix uninit-memory access for partial initialized inode	2020-03-06 07:06:09 -06:00
freevxfs
fscache
fuse
gfs2	We've got a lot of patches (39) for this merge window. Most of these patches	2020-03-31 14:16:03 -07:00
hfs
hfsplus	hfsplus: fix crash and filesystem corruption when deleting files	2020-04-10 15:36:20 -07:00
hostfs	hostfs: Use kasprintf() instead of fixed buffer formatting	2020-03-29 23:23:00 +02:00
hpfs
hugetlbfs	hugetlbfs: Use i_mmap_rwsem to address page fault/truncate race	2020-04-02 09:35:32 -07:00
iomap	fibmap: Warn and return an error in case of block > INT_MAX	2020-04-30 07:57:46 -07:00
isofs
jbd2	jbd2: improve comments about freeing data buffers whose page mapping is NULL	2020-03-05 20:25:05 -05:00
jffs2
jfs
kernfs	kernfs: Add option to enable user xattrs	2020-03-16 15:53:47 -04:00
lockd
minix
nfs	NFS: Fix a race in __nfs_list_for_each_server()	2020-04-30 15:08:26 -04:00
nfs_common
nfsd	SUNRPC: Fix backchannel RPC soft lockups	2020-04-17 12:40:31 -04:00
nilfs2
nls
notify	fanotify: Fix the checks in fanotify_fsid_equal	2020-03-30 12:40:53 +02:00
ntfs	fs/buffer: Make BH_Uptodate_Lock bit_spin_lock a regular spinlock_t	2020-03-28 13:21:08 +01:00
ocfs2	dlmfs_file_write(): fix the bogosity in handling non-zero *ppos	2020-04-23 13:45:27 -04:00
omfs
openpromfs
orangefs	orangefs: don't mess with I_DIRTY_TIMES in orangefs_flush	2020-04-08 09:39:11 -04:00
overlayfs	ovl: enable xino automatically in more cases	2020-03-27 16:51:02 +01:00
proc	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2020-04-25 12:25:32 -07:00
pstore	pstore/ram: Replace zero-length array with flexible-array member	2020-03-09 14:45:40 -07:00
qnx4
qnx6
quota
ramfs
reiserfs	reiserfs: clean up several indentation issues	2020-04-07 10:43:44 -07:00
romfs
squashfs
sysfs	sysfs: remove redundant __compat_only_sysfs_link_entry_to_kobj fn	2020-04-05 11:34:35 -07:00
sysv
tracefs
ubifs	This pull request contains fixes for UBI and UBIFS:	2020-04-07 12:40:56 -07:00
udf	change email address for Pali Rohár	2020-04-10 15:36:22 -07:00
ufs
unicode	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
vboxsf
verity
xfs	xfs: move inode flush to the sync workqueue	2020-04-16 09:07:42 -07:00
zonefs	zonfs: Fix handling of read-only zones	2020-03-25 11:28:26 +09:00
aio.c	aio: fix async fsync creds	2020-05-14 16:44:24 +02:00
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf.c	fs/binfmt_elf.c: don't free interpreter's ELF pheaders on common path	2020-04-07 10:43:44 -07:00
binfmt_elf_fdpic.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
block_dev.c	block: remove unused header	2020-04-21 09:51:10 -06:00
buffer.c	block-5.7-2020-04-24	2020-04-24 12:44:19 -07:00
char_dev.c	vfs: allow unprivileged whiteout creation	2020-05-14 16:44:23 +02:00
compat.c
compat_binfmt_elf.c
coredump.c	coredump: fix null pointer dereference on coredump	2020-04-21 11:11:56 -07:00
d_path.c
dax.c	dax,iomap: Add helper dax_iomap_zero() to zero a range	2020-04-02 19:15:03 -07:00
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c	fs/epoll: make nesting accounting safe for -rt kernel	2020-04-07 10:43:44 -07:00
exec.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2020-04-02 11:22:17 -07:00
fcntl.c	fcntl: Distribute switch variables for initialization	2020-03-03 10:55:06 -05:00
fhandle.c
file.c	io_uring: make sure openat/openat2 honor rlimit nofile	2020-03-20 08:47:27 -06:00
file_table.c
filesystems.c	fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once()	2020-04-10 15:36:22 -07:00
fs-writeback.c
fs_context.c
fs_parser.c	fs_parse: remove pr_notice() about each validation	2020-04-02 09:35:26 -07:00
fs_pin.c
fs_struct.c
fs_types.c
fsopen.c
inode.c	futex: Fix inode life-time issue	2020-03-06 11:06:15 +01:00
internal.h	Merge branch 'work.dotdot1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-04-02 12:30:08 -07:00
io-wq.c	io_uring: use io-wq manager as backup task if task is exiting	2020-04-03 11:35:57 -06:00
io-wq.h	io_uring: use io-wq manager as backup task if task is exiting	2020-04-03 11:35:57 -06:00
io_uring.c	io_uring: punt splice async because of inode mutex	2020-05-01 08:50:57 -06:00
ioctl.c	fibmap: Warn and return an error in case of block > INT_MAX	2020-04-30 07:57:46 -07:00
Kconfig	exfat: add Kconfig and Makefile	2020-03-05 21:00:40 -05:00
Kconfig.binfmt
libfs.c	libfs: fix infoleak in simple_attr_read()	2020-03-24 13:27:16 +01:00
locks.c	locks: reinstate locks_delete_block optimization	2020-03-18 13:03:38 -07:00
Makefile	exfat: add Kconfig and Makefile	2020-03-05 21:00:40 -05:00
mbcache.c
mount.h	proc/mounts: add cursor	2020-05-14 16:44:24 +02:00
mpage.c
namei.c	vfs: allow unprivileged whiteout creation	2020-05-14 16:44:23 +02:00
namespace.c	proc/mounts: add cursor	2020-05-14 16:44:24 +02:00
no-block.c
nsfs.c	fs/nsfs.c: Added ns_match	2020-03-12 17:33:11 -07:00
open.c	Merge branch 'work.dotdot1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-04-02 12:30:08 -07:00
pipe.c	mm: kmem: rename memcg_kmem_(un)charge() into memcg_kmem_(un)charge_page()	2020-04-02 09:35:28 -07:00
pnode.c	propagate_one(): mnt_set_mountpoint() needs mount_lock	2020-04-27 10:37:14 -04:00
pnode.h
posix_acl.c
proc_namespace.c	proc/mounts: add cursor	2020-05-14 16:44:24 +02:00
read_write.c	powerpc: Add back __ARCH_WANT_SYS_LLSEEK macro	2020-04-03 00:09:59 +11:00
readdir.c
select.c
seq_file.c	fs/seq_file.c: seq_read(): add info message about buggy .next functions	2020-04-10 15:36:22 -07:00
signalfd.c
splice.c	splice: make do_splice public	2020-03-02 14:04:31 -07:00
stack.c
stat.c
statfs.c
super.c	Fix use after free in get_tree_bdev()	2020-04-28 14:37:40 -07:00
sync.c
timerfd.c
userfaultfd.c	userfaultfd: wp: declare _UFFDIO_WRITEPROTECT conditionally	2020-04-07 10:43:40 -07:00
utimes.c
xattr.c	kernfs: Add removed_size out param for simple_xattr_set	2020-03-16 15:53:47 -04:00