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e02ba72aab
linux/fs
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Anatol Pomozov e02ba72aab aio: block io_destroy() until all context requests are completed 
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>
2014-04-16 13:38:04 -04:00
..
9p mm: implement ->map_pages for page cache 2014-04-07 16:35:53 -07:00
adfs fs/adfs/super.c: add __init to init_inodecache() 2014-04-07 16:36:08 -07:00
affs affs: add mount option to avoid filename truncates 2014-04-07 16:36:08 -07:00
afs mm + fs: store shadow entries in page cache 2014-04-03 16:21:01 -07:00
autofs4 autofs4: check dev ioctl size before allocating 2014-04-08 16:48:51 -07:00
befs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
bfs fs/bfs/inode.c: add __init to init_inodecache() 2014-04-07 16:36:08 -07:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
cachefiles Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
ceph ceph: fix pr_fmt() redefinition 2014-04-12 15:39:53 -07:00
cifs cifs: Use min_t() when comparing "size_t" and "unsigned long" 2014-04-13 14:10:26 -07:00
coda Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
configfs
cramfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
debugfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
devpts fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
dlm net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
ecryptfs Merge branch 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2014-04-04 14:03:05 -07:00
efivarfs
efs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
exofs Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd 2014-04-10 14:33:02 -07:00
exportfs
ext2 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-04-07 17:59:17 -07:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-04-07 17:59:17 -07:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
f2fs Merge branch 'akpm' (incoming from Andrew) 2014-04-07 16:38:06 -07:00
fat Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
freevxfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
fscache
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
gfs2 mm: implement ->map_pages for page cache 2014-04-07 16:35:53 -07:00
hfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
hfsplus Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
hostfs mm + fs: store shadow entries in page cache 2014-04-03 16:21:01 -07:00
hpfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
hppfs
hugetlbfs mm, hugetlb: unify region structure handling 2014-04-03 16:20:59 -07:00
isofs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-04-07 17:59:17 -07:00
jbd
jbd2 jbd2: improve error messages for inconsistent journal heads 2014-03-12 16:38:03 -04:00
jffs2 MTD updates for 3.15: 2014-04-07 10:17:30 -07:00
jfs Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
kernfs Merge branch 'akpm' (incoming from Andrew) 2014-04-03 16:22:16 -07:00
lockd lockd: ensure we tear down any live sockets when socket creation fails during lockd_up 2014-03-28 10:43:08 -04:00
logfs mm + fs: store shadow entries in page cache 2014-04-03 16:21:01 -07:00
minix Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
ncpfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-04-12 17:31:22 -07:00
nfs mm: implement ->map_pages for page cache 2014-04-07 16:35:53 -07:00
nfs_common
nfsd Merge branch 'for-3.15' of git://linux-nfs.org/~bfields/linux 2014-04-08 18:28:14 -07:00
nilfs2 mm: implement ->map_pages for page cache 2014-04-07 16:35:53 -07:00
nls
notify fanotify: move unrelated handling from copy_event_to_user() 2014-04-03 16:20:51 -07:00
ntfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
ocfs2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-04-12 17:31:22 -07:00
omfs mm + fs: store shadow entries in page cache 2014-04-03 16:21:01 -07:00
openpromfs fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
proc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
pstore Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
qnx4 fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
qnx6 fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
quota Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-04-07 17:59:17 -07:00
ramfs
reiserfs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-04-07 17:59:17 -07:00
romfs fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
squashfs fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
sysfs Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()" 2014-03-25 20:54:57 -07:00
sysv Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
ubifs mm: implement ->map_pages for page cache 2014-04-07 16:35:53 -07:00
udf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
ufs fs/ufs: remove unused ufs_super_block_third pointer 2014-04-07 16:36:16 -07:00
xfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
aio.c aio: block io_destroy() until all context requests are completed 2014-04-16 13:38:04 -04:00
anon_inodes.c vfs: Allocate anon_inode_inode in anon_inode_init() 2014-03-27 09:52:54 -07:00
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c exec: kill the unnecessary mm->def_flags setting in load_elf_binary() 2014-04-07 16:35:52 -07:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c binfmt_misc: add missing 'break' statement 2014-04-03 16:21:16 -07:00
binfmt_script.c
binfmt_som.c
bio-integrity.c block: Ensure we only enable integrity metadata for reads and writes 2014-04-09 08:00:06 -06:00
bio.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
block_dev.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
buffer.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c
compat.c Merge branch 'locks-3.15' of git://git.samba.org/jlayton/linux 2014-04-04 14:21:20 -07:00
coredump.c
dcache.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2014-04-08 09:52:16 -07:00
dcookies.c
direct-io.c xfs: update for 3.15-rc1 2014-04-04 15:50:08 -07:00
drop_caches.c drop_caches: add some documentation and info message 2014-04-03 16:21:04 -07:00
eventfd.c
eventpoll.c
exec.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
fcntl.c locks: add new fcntl cmd values for handling file private locks 2014-03-31 08:24:43 -04:00
fhandle.c
file_table.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
filesystems.c sys_sysfs: Add CONFIG_SYSFS_SYSCALL 2014-04-03 16:21:05 -07:00
fs_struct.c
fs-writeback.c One of the main highlights this time, is not the patches themselves 2014-04-04 14:49:16 -07:00
inode.c Major changes for 3.14 include support for the newly added ZERO_RANGE 2014-04-04 15:39:39 -07:00
internal.h
ioctl.c
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c
locks.c locks: make locks_mandatory_area check for file-private locks 2014-03-31 08:24:43 -04:00
Makefile
mbcache.c ext4: each filesystem creates and uses its own mb_cache 2014-03-18 19:24:49 -04:00
mount.h reduce m_start() cost... 2014-04-01 23:19:09 -04:00
mpage.c
namei.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
namespace.c VFS: Make delayed_free() call free_vfsmnt() 2014-04-01 23:19:18 -04:00
no-block.c
open.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-04-12 14:49:50 -07:00
pipe.c switch pipe_read() to copy_page_to_iter() 2014-04-01 23:19:22 -04:00
pnode.c smarter propagate_mnt() 2014-04-01 23:19:08 -04:00
pnode.h smarter propagate_mnt() 2014-04-01 23:19:08 -04:00
posix_acl.c One of the main highlights this time, is not the patches themselves 2014-04-04 14:49:16 -07:00
proc_namespace.c reduce m_start() cost... 2014-04-01 23:19:09 -04:00
read_write.c Merge branch 'compat' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2014-03-31 14:32:17 -07:00
readdir.c
select.c
seq_file.c
signalfd.c
splice.c switch vmsplice_to_user() to copy_page_to_iter() 2014-04-01 23:19:23 -04:00
stack.c
stat.c
statfs.c
super.c fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
sync.c
timerfd.c
utimes.c
xattr.c