Revision bf294b41cefcb22fc3139e0f42c5b3f06728bd5e authored by Trond Myklebust on 21 February 2011, 19:05:41 UTC, committed by Trond Myklebust on 10 March 2011, 20:04:52 UTC
Although they run as rpciod background tasks, under normal operation (i.e. no SIGKILL), functions like nfs_sillyrename(), nfs4_proc_unlck() and nfs4_do_close() want to be fully synchronous. This means that when we exit, we want all references to the rpc_task to be gone, and we want any dentry references etc. held by that task to be released. For this reason these functions call __rpc_wait_for_completion_task(), followed by rpc_put_task() in the expectation that the latter will be releasing the last reference to the rpc_task, and thus ensuring that the callback_ops->rpc_release() has been called synchronously. This patch fixes a race which exists due to the fact that rpciod calls rpc_complete_task() (in order to wake up the callers of __rpc_wait_for_completion_task()) and then subsequently calls rpc_put_task() without ensuring that these two steps are done atomically. In order to avoid adding new spin locks, the patch uses the existing waitqueue spin lock to order the rpc_task reference count releases between the waiting process and rpciod. The common case where nobody is waiting for completion is optimised for by checking if the RPC_TASK_ASYNC flag is cleared and/or if the rpc_task reference count is 1: in those cases we drop trying to grab the spin lock, and immediately free up the rpc_task. Those few processes that need to put the rpc_task from inside an asynchronous context and that do not care about ordering are given a new helper: rpc_put_task_async(). Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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File | Mode | Size |
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9p | ||
adfs | ||
affs | ||
afs | ||
autofs4 | ||
befs | ||
bfs | ||
btrfs | ||
cachefiles | ||
ceph | ||
cifs | ||
coda | ||
configfs | ||
cramfs | ||
debugfs | ||
devpts | ||
dlm | ||
ecryptfs | ||
efs | ||
exofs | ||
exportfs | ||
ext2 | ||
ext3 | ||
ext4 | ||
fat | ||
freevxfs | ||
fscache | ||
fuse | ||
gfs2 | ||
hfs | ||
hfsplus | ||
hostfs | ||
hpfs | ||
hppfs | ||
hugetlbfs | ||
isofs | ||
jbd | ||
jbd2 | ||
jffs2 | ||
jfs | ||
lockd | ||
logfs | ||
minix | ||
ncpfs | ||
nfs | ||
nfs_common | ||
nfsd | ||
nilfs2 | ||
nls | ||
notify | ||
ntfs | ||
ocfs2 | ||
omfs | ||
openpromfs | ||
partitions | ||
proc | ||
qnx4 | ||
quota | ||
ramfs | ||
reiserfs | ||
romfs | ||
squashfs | ||
sysfs | ||
sysv | ||
ubifs | ||
udf | ||
ufs | ||
xfs | ||
Kconfig | -rw-r--r-- | 5.3 KB |
Kconfig.binfmt | -rw-r--r-- | 6.4 KB |
Makefile | -rw-r--r-- | 4.0 KB |
aio.c | -rw-r--r-- | 47.7 KB |
anon_inodes.c | -rw-r--r-- | 6.3 KB |
attr.c | -rw-r--r-- | 6.6 KB |
bad_inode.c | -rw-r--r-- | 7.8 KB |
binfmt_aout.c | -rw-r--r-- | 12.4 KB |
binfmt_elf.c | -rw-r--r-- | 53.7 KB |
binfmt_elf_fdpic.c | -rw-r--r-- | 48.7 KB |
binfmt_em86.c | -rw-r--r-- | 2.8 KB |
binfmt_flat.c | -rw-r--r-- | 26.8 KB |
binfmt_misc.c | -rw-r--r-- | 15.2 KB |
binfmt_script.c | -rw-r--r-- | 2.8 KB |
binfmt_som.c | -rw-r--r-- | 7.4 KB |
bio-integrity.c | -rw-r--r-- | 21.2 KB |
bio.c | -rw-r--r-- | 39.5 KB |
block_dev.c | -rw-r--r-- | 39.4 KB |
buffer.c | -rw-r--r-- | 87.2 KB |
char_dev.c | -rw-r--r-- | 13.8 KB |
compat.c | -rw-r--r-- | 55.6 KB |
compat_binfmt_elf.c | -rw-r--r-- | 3.5 KB |
compat_ioctl.c | -rw-r--r-- | 45.8 KB |
dcache.c | -rw-r--r-- | 78.0 KB |
dcookies.c | -rw-r--r-- | 6.8 KB |
direct-io.c | -rw-r--r-- | 35.2 KB |
drop_caches.c | -rw-r--r-- | 1.3 KB |
eventfd.c | -rw-r--r-- | 11.0 KB |
eventpoll.c | -rw-r--r-- | 42.5 KB |
exec.c | -rw-r--r-- | 48.6 KB |
fcntl.c | -rw-r--r-- | 18.3 KB |
fifo.c | -rw-r--r-- | 3.2 KB |
file.c | -rw-r--r-- | 11.7 KB |
file_table.c | -rw-r--r-- | 12.1 KB |
filesystems.c | -rw-r--r-- | 6.4 KB |
fs-writeback.c | -rw-r--r-- | 34.2 KB |
fs_struct.c | -rw-r--r-- | 3.9 KB |
generic_acl.c | -rw-r--r-- | 4.7 KB |
inode.c | -rw-r--r-- | 44.6 KB |
internal.h | -rw-r--r-- | 2.8 KB |
ioctl.c | -rw-r--r-- | 15.9 KB |
ioprio.c | -rw-r--r-- | 5.0 KB |
libfs.c | -rw-r--r-- | 25.3 KB |
locks.c | -rw-r--r-- | 58.4 KB |
mbcache.c | -rw-r--r-- | 16.3 KB |
mpage.c | -rw-r--r-- | 19.7 KB |
namei.c | -rw-r--r-- | 87.8 KB |
namespace.c | -rw-r--r-- | 63.1 KB |
nfsctl.c | -rw-r--r-- | 2.4 KB |
no-block.c | -rw-r--r-- | 688 bytes |
open.c | -rw-r--r-- | 23.9 KB |
pipe.c | -rw-r--r-- | 28.4 KB |
pnode.c | -rw-r--r-- | 9.3 KB |
pnode.h | -rw-r--r-- | 1.1 KB |
posix_acl.c | -rw-r--r-- | 8.6 KB |
read_write.c | -rw-r--r-- | 20.8 KB |
read_write.h | -rw-r--r-- | 542 bytes |
readdir.c | -rw-r--r-- | 6.9 KB |
select.c | -rw-r--r-- | 24.3 KB |
seq_file.c | -rw-r--r-- | 17.8 KB |
signalfd.c | -rw-r--r-- | 7.5 KB |
splice.c | -rw-r--r-- | 46.5 KB |
stack.c | -rw-r--r-- | 2.7 KB |
stat.c | -rw-r--r-- | 10.5 KB |
statfs.c | -rw-r--r-- | 5.2 KB |
super.c | -rw-r--r-- | 26.9 KB |
sync.c | -rw-r--r-- | 9.9 KB |
timerfd.c | -rw-r--r-- | 6.5 KB |
utimes.c | -rw-r--r-- | 5.6 KB |
xattr.c | -rw-r--r-- | 15.6 KB |
xattr_acl.c | -rw-r--r-- | 2.3 KB |
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