linux/fs
Jaegeuk Kim 3843154598 f2fs: introduce large directory support
This patch introduces an i_dir_level field to support large directory.

Previously, f2fs maintains multi-level hash tables to find a dentry quickly
from a bunch of chiild dentries in a directory, and the hash tables consist of
the following tree structure as below.

In Documentation/filesystems/f2fs.txt,

----------------------
A : bucket
B : block
N : MAX_DIR_HASH_DEPTH
----------------------

level #0   | A(2B)
           |
level #1   | A(2B) - A(2B)
           |
level #2   | A(2B) - A(2B) - A(2B) - A(2B)
     .     |   .       .       .       .
level #N/2 | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
     .     |   .       .       .       .
level #N   | A(4B) - A(4B) - A(4B) - A(4B) - A(4B) - ... - A(4B)

But, if we can guess that a directory will handle a number of child files,
we don't need to traverse the tree from level #0 to #N all the time.
Since the lower level tables contain relatively small number of dentries,
the miss ratio of the target dentry is likely to be high.

In order to avoid that, we can configure the hash tables sparsely from level #0
like this.

level #0   | A(2B) - A(2B) - A(2B) - A(2B)

level #1   | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
     .     |   .       .       .       .
level #N/2 | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
     .     |   .       .       .       .
level #N   | A(4B) - A(4B) - A(4B) - A(4B) - A(4B) - ... - A(4B)

With this structure, we can skip the ineffective tree searches in lower level
hash tables.

This patch adds just a facility for this by introducing i_dir_level in
f2fs_inode.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2014-02-27 19:56:09 +09:00
..
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 affs: use ->kill_sb() to simplify ->put_super() and failure exits of ->mount() 2014-01-25 03:13:01 -05:00
afs afs: proc cells and rootcell are writeable 2014-02-01 10:59:39 -08:00
autofs4 autofs: fix symlinks aren't checked for expiry 2014-01-23 16:36:59 -08:00
befs befs: iget_locked() doesn't return an ERR_PTR 2014-01-25 03:14:38 -05:00
bfs
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2014-02-16 11:05:27 -08:00
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: fix missing dput in ceph_set_acl 2014-01-31 08:14:06 -08:00
cifs Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6 2014-02-10 10:33:50 -08:00
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 fix O_SYNC|O_APPEND syncing the wrong range on write() 2014-02-09 15:18:09 -05:00
f2fs f2fs: introduce large directory support 2014-02-27 19:56:09 +09:00
fat fat: rcu-delay unloading nls and freeing sbi 2013-10-24 23:43:28 -04:00
freevxfs
fscache Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block 2013-11-14 12:08:14 +09:00
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 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-02-01 10:43:45 -08:00
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
hugetlbfs
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: rename obsoleted msg JBD->JBD2 2013-12-08 21:14:59 -05:00
jffs2 MTD updates for 3.14: 2014-01-28 18:56:37 -08:00
jfs jfs: fix generic posix ACL regression 2014-02-08 10:50:58 -06:00
kernfs kernfs: make kernfs_deactivate() honor KERNFS_LOCKDEP flag 2014-02-05 11:44:04 -08:00
lockd lockd: send correct lock when granting a delayed lock. 2014-02-13 14:55:02 -05:00
logfs Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
minix
ncpfs ncpfs: rcu-delay unload_nls() and freeing ncp_server 2013-10-24 23:43:28 -04:00
nfs mm: fix page leak at nfs_symlink() 2014-02-10 16:01:42 -08:00
nfs_common
nfsd nfsd4: fix acl buffer overrun 2014-02-11 13:48:11 -05:00
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 fanotify: Fix use after free for permission events 2014-01-29 13:57:17 +01:00
ntfs fix O_SYNC|O_APPEND syncing the wrong range on write() 2014-02-09 15:18:09 -05:00
ocfs2 ocfs2: check existence of old dentry in ocfs2_link() 2014-02-10 16:01:43 -08:00
omfs
openpromfs
proc vmcore: prevent PT_NOTE p_memsz overflow during header update 2014-02-10 16:01:40 -08:00
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 genetlink: make multicast groups const, prevent abuse 2013-11-19 16:39:06 -05:00
ramfs fs/ramfs: move ramfs_aops to inode.c 2014-01-23 16:36:58 -08:00
reiserfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-01-28 08:38:04 -08:00
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 Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers" 2014-01-13 14:05:13 -08:00
sysv
ubifs fs/ubifs: use rbtree postorder iteration helper instead of opencoding 2014-01-23 16:37:03 -08:00
udf udf: Fix lockdep warning from udf_symlink() 2013-12-23 22:02:16 +01:00
ufs
xfs fix O_SYNC|O_APPEND syncing the wrong range on write() 2014-02-09 15:18:09 -05:00
aio.c Merge git://git.kvack.org/~bcrl/aio-next 2013-12-22 11:03:49 -08:00
anon_inodes.c ... and kill anon_inode_getfile_private() 2013-11-09 00:16:28 -05:00
attr.c fs: fix iversion handling 2013-12-05 16:36:21 -06:00
bad_inode.c
binfmt_aout.c dump_skip(): dump_seek() replacement taking coredump_params 2013-11-09 00:16:26 -05:00
binfmt_elf_fdpic.c elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo) 2013-11-09 00:16:30 -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_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 fs: Mark function as static in fs/bio-integrity.c 2014-02-09 13:56:23 -07:00
bio.c block: Fix cloning of discard/write same bios 2014-02-11 08:40:45 -07:00
block_dev.c
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_binfmt_elf.c
compat_ioctl.c fs/compat_ioctl.c: fix an underflow issue (harmless) 2014-01-21 16:19:42 -08:00
compat.c
coredump.c coredump: make __get_dumpable/get_dumpable inline, kill fs/coredump.h 2014-01-23 16:37:01 -08:00
dcache.c __dentry_path() fixes 2014-01-26 12:37:55 -05:00
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
eventfd.c eventfd_ctx_fdget(): use fdget() instead of fget() 2014-01-25 03:13:04 -05:00
eventpoll.c epoll: do not take the nested ep->mtx on EPOLL_CTL_DEL 2014-01-02 14:40:30 -08:00
exec.c execve: use 'struct filename *' for executable name passing 2014-02-05 12:54:53 -08:00
fcntl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
fhandle.c
file_table.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
file.c fs/file.c:fdtable: avoid triggering OOMs from alloc_fdmem 2014-02-10 16:01:41 -08:00
filesystems.c
fs_struct.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
fs-writeback.c writeback: Fix data corruption on NFS 2013-12-14 04:21:26 +08:00
inode.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
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
Kconfig fs: remove generic_acl 2014-01-26 08:26:40 -05:00
Kconfig.binfmt
libfs.c consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
locks.c locks: missing unlock on error in generic_add_lease() 2013-11-13 07:30:53 -05:00
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
mbcache.c
mount.h vfs: Is mounted should be testing mnt_ns for NULL or error. 2014-01-26 08:26:42 -05:00
mpage.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
namei.c execve: use 'struct filename *' for executable name passing 2014-02-05 12:54:53 -08:00
namespace.c Driver core / sysfs patches for 3.14-rc1 2014-01-20 15:49:44 -08:00
no-block.c
open.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
pipe.c fs/pipe.c: skip file_update_time on frozen fs 2014-01-23 16:37:00 -08:00
pnode.c split __lookup_mnt() in two functions 2013-10-24 23:35:00 -04:00
pnode.h
posix_acl.c fs: get_acl() must be allowed to return EOPNOTSUPP 2014-02-03 17:12:37 -05:00
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 fs/compat: fix parameter handling for compat readv/writev syscalls 2014-01-29 16:22:39 -08:00
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/super.c: sync ro remount after blocking writers 2014-01-31 14:29:36 -05:00
sync.c fix O_SYNC|O_APPEND syncing the wrong range on write() 2014-02-09 15:18:09 -05:00
timerfd.c
utimes.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
xattr.c