linux/fs
Dave Chinner d0eb2f38b2 xfs: convert grant head manipulations to lockless algorithm
The only thing that the grant lock remains to protect is the grant head
manipulations when adding or removing space from the log. These calculations
are already based on atomic variables, so we can already update them safely
without locks. However, the grant head manpulations require atomic multi-step
calculations to be executed, which the algorithms currently don't allow.

To make these multi-step calculations atomic, convert the algorithms to
compare-and-exchange loops on the atomic variables. That is, we sample the old
value, perform the calculation and use atomic64_cmpxchg() to attempt to update
the head with the new value. If the head has not changed since we sampled it,
it will succeed and we are done. Otherwise, we rerun the calculation again from
a new sample of the head.

This allows us to remove the grant lock from around all the grant head space
manipulations, and that effectively removes the grant lock from the log
completely. Hence we can remove the grant lock completely from the log at this
point.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21 12:29:14 +11:00
..
9p convert v9fs 2010-10-29 04:16:38 -04:00
adfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
affs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
afs convert afs 2010-10-29 04:17:13 -04:00
autofs4 convert get_sb_nodev() users 2010-10-29 04:16:31 -04:00
befs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
bfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
btrfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable 2010-11-29 14:11:08 -08:00
cachefiles llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2010-11-19 15:32:22 -08:00
cifs cifs: fix a memleak in cifs_setattr_nounix() 2010-11-09 15:17:53 +00:00
coda convert get_sb_nodev() users 2010-10-29 04:16:31 -04:00
configfs convert get_sb_single() users 2010-10-29 04:16:28 -04:00
cramfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
debugfs convert get_sb_single() users 2010-10-29 04:16:28 -04:00
devpts convert get_sb_single() users 2010-10-29 04:16:28 -04:00
dlm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm 2010-10-22 17:33:16 -07:00
ecryptfs BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
efs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
exofs convert get_sb_nodev() users 2010-10-29 04:16:31 -04:00
exportfs exportfs: use dget_parent 2010-10-25 21:26:13 -04:00
ext2 new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
ext3 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
ext4 ext4: Add EXT4_IOC_TRIM ioctl to handle batched discard 2010-11-19 21:47:07 -05:00
fat new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
freevxfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
fscache Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
fuse fuse: fix attributes after open(O_TRUNC) 2010-11-25 06:50:41 +09:00
gfs2 GFS2: Userland expects quota limit/warn/usage in 512b blocks 2010-11-19 11:20:29 +00:00
hfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
hfsplus new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
hostfs convert get_sb_nodev() users 2010-10-29 04:16:31 -04:00
hpfs Merge branches 'irq-core-for-linus' and 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-31 20:40:24 -04:00
hppfs convert get_sb_nodev() users 2010-10-29 04:16:31 -04:00
hugetlbfs hugetlbfs: lessen the impact of a deprecation warning 2010-11-12 07:55:32 -08:00
isofs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
jbd Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 2010-10-27 20:13:18 -07:00
jbd2 jbd2: fix /proc/fs/jbd2/<dev> when using an external journal 2010-11-17 21:46:26 -05:00
jffs2 Merge git://git.infradead.org/mtd-2.6 2010-10-30 08:31:35 -07:00
jfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
lockd BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
logfs fs: logfs: Fix up MTD=y build. 2010-11-01 16:34:56 -04:00
minix new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
ncpfs BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
nfs NFS: Ensure we return the dirent->d_type when it is known 2010-11-22 13:24:48 -05:00
nfs_common
nfsd BKL: remove references to lock_kernel from comments 2010-11-17 08:59:32 -08:00
nilfs2 nilfs2: fix typo in comment of nilfs_dat_move function 2010-11-24 12:51:48 +09:00
nls
notify make fanotify_read() restartable across signals 2010-10-30 14:07:35 -04:00
ntfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
ocfs2 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
omfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
openpromfs sparc: fix openpromfs compile 2010-11-08 14:29:39 -08:00
partitions Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block 2010-10-25 07:45:10 -07:00
proc pagemap: set pagemap walk limit to PMD boundary 2010-11-25 06:50:46 +09:00
qnx4 new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
quota quota: Fix possible oops in __dquot_initialize() 2010-10-28 01:30:06 +02:00
ramfs convert get_sb_nodev() users 2010-10-29 04:16:31 -04:00
reiserfs reiserfs: fix inode mutex - reiserfs lock misordering 2010-11-25 06:50:48 +09:00
romfs convert get_sb_mtd() users to ->mount() 2010-10-29 04:16:26 -04:00
squashfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus 2010-10-29 08:48:58 -07:00
sysfs convert sysfs 2010-10-29 04:17:08 -04:00
sysv new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
ubifs convert ubifs 2010-10-29 04:16:36 -04:00
udf new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
ufs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
xfs xfs: convert grant head manipulations to lockless algorithm 2010-12-21 12:29:14 +11:00
aio.c new helper: ihold() 2010-10-25 21:26:11 -04:00
anon_inodes.c convert get_sb_pseudo() users 2010-10-29 04:16:33 -04:00
attr.c check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
bad_inode.c bkl: Remove locked .ioctl file operation 2010-08-14 00:24:24 +02:00
binfmt_aout.c Don't dump task struct in a.out core-dumps 2010-10-14 10:57:40 -07:00
binfmt_elf_fdpic.c
binfmt_elf.c ARM: 6342/1: fix ASLR of PIE executables 2010-10-08 10:02:53 +01:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c convert get_sb_single() users 2010-10-29 04:16:28 -04:00
binfmt_script.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
binfmt_som.c
bio-integrity.c fs/bio-integrity.c: return -ENOMEM on kmalloc failure 2010-08-23 13:36:59 +02:00
bio.c bio: take care not overflow page count when mapping/copying user data 2010-11-10 14:40:43 +01:00
block_dev.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
buffer.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-10-26 17:58:44 -07:00
char_dev.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
compat_binfmt_elf.c
compat_ioctl.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
compat.c fs/compat.c: fix build on MIPS/s390 2010-10-30 08:19:35 -07:00
dcache.c fs: use RCU read side protection in d_validate 2010-10-25 21:26:13 -04:00
dcookies.c
direct-io.c fs/direct-io.c: fix truncation error in dio_complete() return 2010-10-26 16:52:13 -07:00
drop_caches.c simplify checks for I_CLEAR/I_FREEING 2010-08-09 16:47:44 -04:00
eventfd.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
eventpoll.c epoll: make epoll_wait() use the hrtimer range feature 2010-10-27 18:03:18 -07:00
exec.c exec: don't turn PF_KTHREAD off when a target command was not found 2010-10-27 18:03:13 -07:00
fcntl.c fasync: Fix placement of FASYNC flag comment 2010-10-27 18:17:02 -07:00
fifo.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
file_table.c fs: allow for more than 2^31 files 2010-10-26 16:52:15 -07:00
file.c vfs: use kmalloc() to allocate fdmem if possible 2010-08-11 08:59:02 -07:00
filesystems.c
fs_struct.c fs: fs_struct rwlock to spinlock 2010-08-18 08:35:46 -04:00
fs-writeback.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable 2010-10-30 09:05:48 -07:00
generic_acl.c vfs: update ctime when changing the file's permission by setfacl 2010-08-18 01:04:22 -04:00
inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-10-26 17:58:44 -07:00
internal.h braino in internal.h 2010-10-29 05:49:13 -04:00
ioctl.c Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2010-11-19 19:46:45 -08:00
ioprio.c ioprio: grab rcu_read_lock in sys_ioprio_{set,get}() 2010-11-15 10:23:31 +01:00
Kconfig Merge 'staging-next' to Linus's tree 2010-10-28 09:44:56 -07:00
Kconfig.binfmt coredump: default CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS=y 2010-10-27 18:03:12 -07:00
libfs.c convert get_sb_pseudo() users 2010-10-29 04:16:33 -04:00
locks.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
Makefile Merge 'staging-next' to Linus's tree 2010-10-28 09:44:56 -07:00
mbcache.c mbcache: Limit the maximum number of cache entries 2010-08-18 06:24:41 -04:00
mpage.c
namei.c fix open/umount race 2010-10-29 04:14:56 -04:00
namespace.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
nfsctl.c
no-block.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
open.c fix open/umount race 2010-10-29 04:14:56 -04:00
pipe.c Un-inline get_pipe_info() helper function 2010-11-28 16:27:19 -08:00
pnode.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
pnode.h
posix_acl.c
read_write.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
read_write.h
readdir.c vfs: fix warning: 'dirent' is used uninitialized in this function 2010-08-09 20:45:05 -07:00
select.c epoll: make epoll_wait() use the hrtimer range feature 2010-10-27 18:03:18 -07:00
seq_file.c fs: take dcache_lock inside __d_path 2010-10-25 21:26:12 -04:00
signalfd.c Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2010-10-26 10:13:10 -07:00
splice.c Export 'get_pipe_info()' to other users 2010-11-28 14:09:57 -08:00
stack.c
stat.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
statfs.c add f_flags to struct statfs(64) 2010-08-09 16:48:44 -04:00
super.c switch get_sb_ns() users 2010-10-29 04:17:03 -04:00
sync.c get rid of file_fsync() 2010-08-09 16:47:43 -04:00
timerfd.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00
utimes.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
xattr_acl.c
xattr.c