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133b81f28e
linux/fs
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Larry Chen 133b81f28e ocfs2: ocfs2_inode_lock_tracker does not distinguish lock level 
ocfs2_inode_lock_tracker as a variant of ocfs2_inode_lock, is used to
prevent deadlock due to recursive lock acquisition.

But this function does not distinguish whether the requested level is EX
or PR.

If a RP lock has been attained, this function will immediately return
success afterwards even an EX lock is requested.

But actually the return value does not mean that the process got a EX
lock, because ocfs2_inode_lock has not been called.

When taking lock levels into account, we face some different situations:

1. no lock is held
   In this case, just lock the inode and return 0

2. We are holding a lock
   For this situation, things diverges into several cases

   wanted     holding	     what to do
   ex		ex	    see 2.1 below
   ex		pr	    see 2.2 below
   pr		ex	    see 2.1 below
   pr		pr	    see 2.1 below

   2.1 lock level that is been held is compatible
   with the wanted level, so no lock action will be tacken.

   2.2 Otherwise, an upgrade is needed, but it is forbidden.

Reason why upgrade within a process is forbidden is that lock upgrade
may cause dead lock.  The following illustrate how it happens.

        process 1                             process 2
ocfs2_inode_lock_tracker(ex=0)
                               <======   ocfs2_inode_lock_tracker(ex=1)

ocfs2_inode_lock_tracker(ex=1)

For the status quo of ocfs2, without this patch, neither a bug nor
end-user impact will be caused because the wrong logic is avoided.

But I'm afraid this generic interface, may be called by other developers
in future and used in this situation.

  a process
ocfs2_inode_lock_tracker(ex=0)
ocfs2_inode_lock_tracker(ex=1)

Link: http://lkml.kernel.org/r/20180510053230.17217-1-lchen@suse.com
Signed-off-by: Larry Chen <lchen@suse.com>
Reviewed-by: Gang He <ghe@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:33 -07:00
..
9p 9p: unify paths in v9fs_vfs_lookup() 2018-05-22 14:28:02 -04:00
adfs adfs_lookup: do not fail with ENOENT on negatives, use d_splice_alias() 2018-05-22 14:27:56 -04:00
affs affs: fix potential memory leak when parsing option 'prefix' 2018-05-28 12:36:41 +02:00
afs Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
autofs4 autofs: mount point create should honour passed in mode 2018-04-20 17:18:35 -07:00
befs befs_lookup(): use d_splice_alias() 2018-05-21 14:30:07 -04:00
bfs bfs_add_entry: pass name/len as qstr pointer 2018-05-22 14:27:50 -04:00
btrfs for-4.18-tag 2018-06-04 14:29:13 -07:00
cachefiles Merge branch 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 10:00:01 -07:00
ceph ceph: fix iov_iter issues in ceph_direct_read_write() 2018-05-10 10:15:12 +02:00
cifs some smb3 fixes for stable, as well as addition of ftrace hooks for cifs.ko, and improvements in compounding and smbdirect (RDMA) 2018-06-04 14:42:46 -07:00
coda vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
configfs
cramfs cramfs_lookup(): use d_splice_alias() 2018-05-22 14:27:51 -04:00
crypto fscrypt: log the crypto algorithm implementations 2018-05-20 16:36:00 -04:00
debugfs debugfs: inode: debugfs_create_dir uses mode permission from parent 2018-05-14 16:48:18 +02:00
devpts devpts: comment devpts_mntget() 2018-03-14 13:31:23 +01:00
dlm dlm: remove O_NONBLOCK flag in sctp_connect_to_sock 2018-05-29 10:48:35 -05:00
ecryptfs Merge branch 'fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into aio-base 2018-05-26 09:16:25 +02:00
efivarfs efivarfs: Limit the rate for non-root to read files 2018-02-22 10:21:02 -08:00
efs
exofs scsi/osd: remove the gfp argument to osd_start_request 2018-05-14 08:55:09 -06:00
exportfs ovl: do not try to reconnect a disconnected origin dentry 2018-04-12 12:04:49 +02:00
ext2 Changes for 4.18: 2018-06-05 13:24:20 -07:00
ext4 Add bunch of cleanups, and add support for the Speck128/256 2018-06-05 15:15:32 -07:00
f2fs Add bunch of cleanups, and add support for the Speck128/256 2018-06-05 15:15:32 -07:00
fat vfat: simplify checks in vfat_lookup() 2018-05-13 12:09:14 -04:00
freevxfs freevxfs_lookup(): use d_splice_alias() 2018-05-22 14:27:51 -04:00
fscache proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
fuse fuse update for 4.18 2018-06-07 08:50:57 -07:00
gfs2 Changes for 4.18: 2018-06-05 13:24:20 -07:00
hfs hfs: don't allow mounting over .../rsrc 2018-05-22 14:28:00 -04:00
hfsplus Merge branch 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 13:46:22 -07:00
hostfs hostfs: rename do_rmdir() to hostfs_do_rmdir() 2018-04-02 20:15:53 +02:00
hpfs
hugetlbfs hugetlbfs: fix bug in pgoff overflow checking 2018-04-05 21:36:21 -07:00
isofs isofs: fix potential memory leak in mount option parsing 2018-04-16 09:47:41 +02:00
jbd2 jbd2: remove NULL check before calling kmem_cache_destroy() 2018-05-20 22:38:26 -04:00
jffs2 do d_instantiate/unlock_new_inode combinations safely 2018-05-11 15:36:37 -04:00
jfs Merge branch 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 10:00:01 -07:00
kernfs Driver core changes for 4.18-rc1 2018-06-05 16:29:19 -07:00
lockd net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
minix minix_lookup: use d_splice_alias() 2018-05-22 14:27:52 -04:00
nfs proc: introduce proc_create_net{,_data} 2018-05-16 07:24:30 +02:00
nfs_common net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
nfsd for-4.18/block-20180603 2018-06-04 07:58:06 -07:00
nilfs2 do d_instantiate/unlock_new_inode combinations safely 2018-05-11 15:36:37 -04:00
nls
notify fsnotify: fix ignore mask logic in send_to_group() 2018-04-13 15:52:49 +02:00
ntfs ntfs: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) call 2018-03-28 01:39:02 -04:00
ocfs2 ocfs2: ocfs2_inode_lock_tracker does not distinguish lock level 2018-06-07 17:34:33 -07:00
omfs omfs_lookup(): report IO errors, use d_splice_alias() 2018-05-22 14:27:58 -04:00
openpromfs openpromfs: switch to d_splice_alias() 2018-05-22 14:27:57 -04:00
orangefs orangefs: fixes and cleanups 2018-06-07 09:23:12 -07:00
overlayfs ovl: use inode_insert5() to hash a newly created inode 2018-05-31 11:06:12 +02:00
proc powerpc updates for 4.18 2018-06-07 10:23:33 -07:00
pstore pstore: fix crypto dependencies without compression 2018-04-06 15:45:33 -07:00
qnx4 qnx4_lookup: use d_splice_alias() 2018-05-22 14:27:52 -04:00
qnx6 qnx6_lookup: switch to d_splice_alias() 2018-05-22 14:27:54 -04:00
quota fs: quota: Replace GFP_ATOMIC with GFP_KERNEL in dquot_init 2018-04-09 17:48:54 +02:00
ramfs
reiserfs Merge branch 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 10:00:01 -07:00
romfs romfs_lookup: switch to d_splice_alias() 2018-05-22 14:27:55 -04:00
squashfs
sysfs unfuck sysfs_mount() 2018-05-21 14:30:09 -04:00
sysv sysv_lookup: use d_splice_alias() 2018-05-22 14:27:53 -04:00
tracefs
ubifs Add bunch of cleanups, and add support for the Speck128/256 2018-06-05 15:15:32 -07:00
udf \n 2018-06-07 09:36:29 -07:00
ufs do d_instantiate/unlock_new_inode combinations safely 2018-05-11 15:36:37 -04:00
xfs Changes for 4.18: 2018-06-05 13:24:20 -07:00
aio.c aio: sanitize the limit checking in io_submit(2) 2018-05-29 23:20:17 -04:00
anon_inodes.c
attr.c fs: Allow superblock owner to replace invalid owners of inodes 2018-05-24 11:57:18 -05:00
bad_inode.c
binfmt_aout.c exec: introduce finalize_exec() before start_thread() 2018-04-11 10:28:37 -07:00
binfmt_elf_fdpic.c exec: introduce finalize_exec() before start_thread() 2018-04-11 10:28:37 -07:00
binfmt_elf.c fs, elf: don't complain MAP_FIXED_NOREPLACE unless -EEXIST error 2018-04-20 17:18:36 -07:00
binfmt_em86.c
binfmt_flat.c exec: introduce finalize_exec() before start_thread() 2018-04-11 10:28:37 -07:00
binfmt_misc.c fs: add ksys_close() wrapper; remove in-kernel calls to sys_close() 2018-04-02 20:16:00 +02:00
binfmt_script.c
block_dev.c fs: convert block_dev.c to bioset_init() 2018-05-30 15:33:32 -06:00
buffer.c fs: move page_cache_seek_hole_data to iomap.c 2018-06-01 18:37:33 -07:00
char_dev.c block, char_dev: Use correct format specifier for unsigned ints 2018-03-15 17:59:24 +01:00
compat_binfmt_elf.c
compat_ioctl.c
compat.c
coredump.c
d_path.c split d_path() and friends into a separate file 2018-03-29 15:07:46 -04:00
dax.c fs/dax.c: use new return type vm_fault_t 2018-06-07 17:34:33 -07:00
dcache.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 10:14:28 -07:00
dcookies.c fs: add do_lookup_dcookie() helper; remove in-kernel call to syscall 2018-04-02 20:15:39 +02:00
direct-io.c block: consistently use GFP_NOIO instead of __GFP_NORECLAIM 2018-05-14 08:55:18 -06:00
drop_caches.c
eventfd.c eventfd: switch to ->poll_mask 2018-05-26 09:16:44 +02:00
eventpoll.c fs: add new vfs_poll and file_can_poll helpers 2018-05-26 09:16:44 +02:00
exec.c umh: introduce fork_usermode_blob() helper 2018-05-23 13:23:39 -04:00
fcntl.c fasync: Fix deadlock between task-context and interrupt-context kill_fasync() 2018-05-01 07:39:50 -04:00
fhandle.c vfs: Copy struct mount.mnt_id to userspace using put_user() 2018-01-15 12:07:51 -08:00
file_table.c
file.c fs: add ksys_close() wrapper; remove in-kernel calls to sys_close() 2018-04-02 20:16:00 +02:00
filesystems.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
fs_pin.c
fs_struct.c
fs-writeback.c bdi: Fix oops in wb_workfn() 2018-05-03 16:11:37 -06:00
inode.c overlayfs fixes for 4.18 2018-06-07 08:53:50 -07:00
internal.h Revert "fs: fold open_check_o_direct into do_dentry_open" 2018-06-03 10:58:23 -07:00
ioctl.c fs: Allow CAP_SYS_ADMIN in s_user_ns to freeze and thaw filesystems 2018-05-24 12:04:28 -05:00
iomap.c fs: use ->is_partially_uptodate in page_cache_seek_hole_data 2018-06-01 18:37:33 -07:00
Kconfig docs/admin-guide/mm: start moving here files from Documentation/vm 2018-04-27 17:02:48 -06:00
Kconfig.binfmt treewide: simplify Kconfig dependencies for removed archs 2018-03-26 15:55:57 +02:00
libfs.c fs, dax: prepare for dax-specific address_space_operations 2018-03-30 11:34:55 -07:00
locks.c proc: introduce proc_create_seq_private 2018-05-16 07:23:35 +02:00
Makefile split d_path() and friends into a separate file 2018-03-29 15:07:46 -04:00
mbcache.c
mount.h
mpage.c
namei.c Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-06-04 15:21:19 -07:00
namespace.c fs: Allow superblock owner to access do_remount_sb() 2018-05-24 12:02:25 -05:00
no-block.c
nsfs.c net: Export open_related_ns() 2018-02-15 15:34:42 -05:00
open.c Revert "fs: fold open_check_o_direct into do_dentry_open" 2018-06-03 10:58:23 -07:00
pipe.c pipe: convert to ->poll_mask 2018-05-26 09:16:44 +02:00
pnode.c
pnode.h
posix_acl.c
proc_namespace.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
read_write.c fs: avoid fdput() after failed fdget() in vfs_dedupe_file_range() 2018-04-15 23:36:26 -04:00
readdir.c fs: add ksys_getdents64() helper; remove in-kernel calls to sys_getdents64() 2018-04-02 20:16:02 +02:00
select.c fs: introduce new ->get_poll_head and ->poll_mask methods 2018-05-26 09:16:44 +02:00
seq_file.c proc: fix smaps and meminfo alignment 2018-05-25 18:12:11 -07:00
signalfd.c signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR} 2018-04-26 19:51:14 -05:00
splice.c fs: add do_vmsplice() helper; remove in-kernel call to syscall 2018-04-02 20:15:40 +02:00
stack.c
stat.c fs: add do_readlinkat() helper; remove internal call to sys_readlinkat() 2018-04-02 20:15:34 +02:00
statfs.c
super.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 10:14:28 -07:00
sync.c Changes for this release: 2018-04-04 12:44:02 -07:00
timerfd.c timerfd: convert to ->poll_mask 2018-05-26 09:16:44 +02:00
userfaultfd.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
utimes.c fs: add do_compat_futimesat() helper; remove in-kernel call to compat syscall 2018-04-02 20:15:44 +02:00
xattr.c vfs: delete unnecessary assignment in vfs_listxattr 2018-05-29 13:22:41 -04:00