linux/fs
Anatol Pomozov 199f5458a1 aio: block io_destroy() until all context requests are completed
commit e02ba72aab upstream.

deletes aio context and all resources related to. It makes sense that
no IO operations connected to the context should be running after the context
is destroyed. As we removed io_context we have no chance to
get requests status or call io_getevents().

man page for io_destroy says that this function may block until
all context's requests are completed. Before kernel 3.11 io_destroy()
blocked indeed, but since aio refactoring in 3.11 it is not true anymore.

Here is a pseudo-code that shows a testcase for a race condition discovered
in 3.11:

  initialize io_context
  io_submit(read to buffer)
  io_destroy()

  // context is destroyed so we can free the resources
  free(buffers);

  // if the buffer is allocated by some other user he'll be surprised
  // to learn that the buffer still filled by an outstanding operation
  // from the destroyed io_context

The fix is straight-forward - add a completion struct and wait on it
in io_destroy, complete() should be called when number of in-fligh requests
reaches zero.

If two or more io_destroy() called for the same context simultaneously then
only the first one waits for IO completion, other calls behaviour is undefined.

Tested: ran http://pastebin.com/LrPsQ4RL testcase for several hours and
  do not see the race condition anymore.

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09 11:18:28 -07:00
..
9p Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-01-28 08:38:04 -08:00
adfs adfs: delayed freeing of sbi 2013-10-24 23:43:27 -04:00
affs fs/affs/super.c: bugfix / double free 2014-06-07 10:28:16 -07:00
afs afs: proc cells and rootcell are writeable 2014-02-01 10:59:39 -08:00
autofs4 autofs: fix lockref lookup 2014-06-07 10:28:20 -07:00
befs befs: iget_locked() doesn't return an ERR_PTR 2014-01-25 03:14:38 -05:00
bfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
btrfs btrfs: allocate raid type kobjects dynamically 2014-06-30 20:12:02 -07:00
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 ceph: clear directory's completeness when creating file 2014-06-07 10:28:20 -07:00
cifs CIFS: fix mount failure with broken pathnames when smb3 mount with mapchars option 2014-07-09 11:18:27 -07:00
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: take headers to fs/cramfs 2014-01-25 03:13:02 -05:00
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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
ecryptfs ecryptfs: fix failure handling in ->readlink() 2014-01-25 03:13:00 -05:00
efivarfs consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
efs efs: get rid of ->put_super() 2014-01-25 03:13:02 -05:00
exofs exofs: Print less in r4w 2014-01-23 18:54:14 +02:00
exportfs exportfs: fix quadratic behavior in filehandle lookup 2013-11-09 00:16:38 -05:00
ext2 ext2/3/4: use generic posix ACL infrastructure 2014-01-25 23:58:19 -05:00
ext3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-01-28 08:38:04 -08:00
ext4 ext4: Fix hole punching for files with indirect blocks 2014-07-09 11:18:27 -07:00
f2fs Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
fat fat: rcu-delay unloading nls and freeing sbi 2013-10-24 23:43:28 -04:00
freevxfs
fscache FS-Cache: Handle removal of unadded object to the fscache_object_list rb tree 2014-02-17 13:47:35 -08:00
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-01-28 08:38:04 -08:00
gfs2 Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
hfs fs/hfs/btree.h: remove duplicate defines 2013-11-13 12:09:32 +09:00
hfsplus hfsplus: add HFSX subfolder count support 2014-03-10 17:26:21 -07:00
hostfs um: hostfs: make functions static 2014-01-26 11:51:09 +01:00
hpfs hpfs: optimize quad buffer loading 2014-02-02 16:24:07 -08:00
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: Revise KERN_EMERG error messages 2013-12-04 12:27:46 +01:00
jbd2 jbd2: fix use after free in jbd2_journal_start_reserved() 2014-02-17 20:33:01 -05:00
jffs2 jffs2: remove from wait queue after schedule() 2014-04-26 17:19:06 -07:00
jfs jfs: set i_ctime when setting ACL 2014-02-13 15:56:05 -06:00
kernfs kernfs: add back missing error check in kernfs_fop_mmap() 2014-06-07 10:28:08 -07:00
lockd lockd: ensure we tear down any live sockets when socket creation fails during lockd_up 2014-05-13 13:32:56 +02:00
logfs Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
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 cache_validity check in nfs_write_pageuptodate() 2014-07-06 18:57:28 -07:00
nfs_common
nfsd nfsd: fix rare symlink decoding bug 2014-07-09 11:18:27 -07:00
nilfs2 Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
nls nls: have register_nls() set ->owner 2014-01-25 03:14:05 -05:00
notify fsnotify: Allocate overflow events with proper type 2014-02-25 11:18:06 +01:00
ntfs fix O_SYNC|O_APPEND syncing the wrong range on write() 2014-02-09 15:18:09 -05:00
ocfs2 ocfs2: fix panic on kfree(xattr->name) 2014-05-06 07:59:36 -07:00
omfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
openpromfs
proc mm: add !pte_present() check on existing hugetlb_entry callbacks 2014-06-11 11:54:13 -07:00
pstore pstore: Don't allow high traffic options on fragile devices 2013-12-20 13:12:01 -08:00
qnx4 qnx4: clean qnx4_fill_super() up 2014-01-25 03:13:03 -05:00
qnx6
quota quota: Fix race between dqput() and dquot_scan_active() 2014-02-20 21:57:04 +01:00
ramfs fs/ramfs: move ramfs_aops to inode.c 2014-01-23 16:36:58 -08:00
reiserfs reiserfs: call truncate_setsize under tailpack mutex 2014-07-06 18:57:29 -07:00
romfs romfs: fix returm err while getting inode in fill_super 2014-01-23 16:37:04 -08:00
squashfs Squashfs: fix failure to unlock pages on decompress error 2013-11-24 01:02:50 +00:00
sysfs sysfs: make sure read buffer is zeroed 2014-06-07 10:28:24 -07:00
sysv sysv: Add forgotten superblock lock init for v7 fs 2013-09-29 22:02:02 -04:00
ubifs UBIFS: Remove incorrect assertion in shrink_tnc() 2014-07-06 18:57:26 -07:00
udf udf: Fix data corruption on file type conversion 2014-02-20 21:56:00 +01:00
ufs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
xfs xfs: xfs_readsb needs to check for magic numbers 2014-07-06 18:57:28 -07:00
Kconfig fs: remove generic_acl 2014-01-26 08:26:40 -05:00
Kconfig.binfmt
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-01-28 08:38:04 -08:00
aio.c aio: block io_destroy() until all context requests are completed 2014-07-09 11:18:28 -07:00
anon_inodes.c vfs: Allocate anon_inode_inode in anon_inode_init() 2014-03-27 09:52:54 -07:00
attr.c fs,userns: Change inode_capable to capable_wrt_inode_uidgid 2014-06-16 13:40:32 -07:00
bad_inode.c
binfmt_aout.c dump_skip(): dump_seek() replacement taking coredump_params 2013-11-09 00:16:26 -05:00
binfmt_elf.c fs: binfmt_elf: remove unused defines INTERPRETER_NONE and INTERPRETER_ELF 2014-01-23 16:36:58 -08:00
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 bio-integrity: Drop bio_integrity_verify BUG_ON in post bip->bip_iter world 2014-02-21 15:56:36 -08:00
bio.c block: Fix cloning of discard/write same bios 2014-02-11 08:40:45 -07:00
block_dev.c a trivial writeback fix 2013-09-13 23:06:40 -04:00
buffer.c mm: __set_page_dirty uses spin_lock_irqsave instead of spin_lock_irq 2014-02-06 13:48:51 -08:00
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
compat_binfmt_elf.c
compat_ioctl.c fs/compat_ioctl.c: fix an underflow issue (harmless) 2014-01-21 16:19:42 -08:00
coredump.c coredump: fix va_list corruption 2014-06-07 10:28:08 -07:00
dcache.c fix races between __d_instantiate() and checks of dentry flags 2014-06-07 10:28:20 -07:00
dcookies.c fs/compat: fix lookup_dcookie() parameter handling 2014-01-29 16:22:40 -08:00
direct-io.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
drop_caches.c shrinker: add node awareness 2013-09-10 18:56:31 -04:00
eventfd.c eventfd_ctx_fdget(): use fdget() instead of fget() 2014-01-25 03:13:04 -05:00
eventpoll.c epoll: fix use-after-free in eventpoll_release_file 2014-06-30 20:12:02 -07:00
exec.c metag: Reduce maximum stack size to 256MB 2014-06-07 10:28:23 -07:00
fcntl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
fhandle.c
file.c vfs: Don't let __fdget_pos() get FMODE_PATH files 2014-03-23 00:03:12 -04:00
file_table.c don't bother with {get,put}_write_access() on non-regular files 2014-05-31 13:20:29 -07:00
filesystems.c
fs-writeback.c bdi: avoid oops on device removal 2014-04-26 17:19:05 -07:00
fs_struct.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
inode.c fs,userns: Change inode_capable to capable_wrt_inode_uidgid 2014-06-16 13:40:32 -07:00
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: allow __break_lease to sleep even when break_time is 0 2014-05-13 13:32:53 +02:00
mbcache.c fs: convert fs shrinkers to new scan/count API 2013-09-10 18:56:31 -04:00
mount.h switch mnt_hash to hlist 2014-03-30 19:18:51 -04:00
mpage.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
namei.c fs,userns: Change inode_capable to capable_wrt_inode_uidgid 2014-06-16 13:40:32 -07:00
namespace.c smarter propagate_mnt() 2014-05-06 07:59:36 -07:00
no-block.c
open.c don't bother with {get,put}_write_access() on non-regular files 2014-05-31 13:20:29 -07:00
pipe.c fs/pipe.c: skip file_update_time on frozen fs 2014-01-23 16:37:00 -08:00
pnode.c smarter propagate_mnt() 2014-05-06 07:59:36 -07:00
pnode.h smarter propagate_mnt() 2014-05-06 07:59:36 -07:00
posix_acl.c posix_acl: handle NULL ACL in posix_acl_equiv_mode 2014-06-07 10:28:16 -07:00
proc_namespace.c fs/proc_namespace.c: simplify testing nsp and nsp->mnt_ns 2014-01-23 16:37:02 -08:00
read_write.c vfs: atomic f_pos access in llseek() 2014-03-23 00:03:12 -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 fuse: fix pipe_buf_operations 2014-01-22 19:36:57 +01:00
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 fs: Don't return 0 from get_anon_bdev 2014-05-31 13:20:31 -07:00
sync.c Revert "writeback: do not sync data dirtied after sync start" 2014-02-22 02:02:28 +01:00
timerfd.c
utimes.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
xattr.c