aboutsummaryrefslogtreecommitdiff
path: root/fs/nilfs2
AgeCommit message (Collapse)Author
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24nilfs2: fix imperfect completion wait in nilfs_wait_on_logsRyusuke Konishi
nilfs_wait_on_logs has a potential to slip out before completion of all bio requests when it met an error. This synchronization fault may cause unexpected results, for instance, violative access to freed segment buffers from an end-bio callback routine. This fixes the issue by ensuring that nilfs_wait_on_logs waits all given logs. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-03-24nilfs2: fix hang-up of cleaner after log writer returned with errorRyusuke Konishi
According to the report from Andreas Beckmann (Message-ID: <4BA54677.3090902@abeckmann.de>), nilfs in 2.6.33 kernel got stuck after a disk full error. This turned out to be a regression by log writer updates merged at kernel 2.6.33. nilfs_segctor_abort_construction, which is a cleanup function for erroneous cases, was skipping writeback completion for some logs. This fixes the bug and would resolve the hang issue. Reported-by: Andreas Beckmann <debian@abeckmann.de> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: stable <stable@kernel.org> [2.6.33.x]
2010-03-22nilfs2: fix duplicate call to nilfs_segctor_cancel_freevRyusuke Konishi
Andreas Beckmann gave me a report that nilfs logged the following warnings when it got a disk full: nilfs_sufile_do_cancel_free: segment 0 must be clean nilfs_sufile_do_cancel_free: segment 1 must be clean These arise from a duplicate call to nilfs_segctor_cancel_freev in an error path of log writer. This will fix the issue. Reported-by: Andreas Beckmann <debian@abeckmann.de> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-03-14nilfs2: remove whitespaces before quoted newlinesRyusuke Konishi
This kills the following checkpatch warnings: WARNING: unnecessary whitespace before a quoted newline #869: FILE: super.c:869: + "remount to a different snapshot. \n", WARNING: unnecessary whitespace before a quoted newline #389: FILE: the_nilfs.c:389: + printk(KERN_ERR "NILFS: too short segment. \n"); Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-03-14nilfs2: remove spaces before tabsRyusuke Konishi
This kills the following checkpatch warnings: WARNING: please, no space before tabs #74: FILE: segment.h:74: +^Iunsigned ^I^Iflags;$ WARNING: please, no space before tabs #35: FILE: segbuf.c:35: +^Iint ^I^I^Istart, end; /* The region to be submitted */$ Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-03-14nilfs2: fix various typos in commentsRyusuke Konishi
This fixes various typos I found in comments of nilfs2. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-03-14nilfs2: fix typo "cout" -> "count" in error messageRyusuke Konishi
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-03-14nilfs2: fix function name typos in docbook commentsRyusuke Konishi
Fixes the following typos in docbook comments: nilfs_detroy_transaction_cache -> nilfs_destroy_transaction_cache nilfs_secgtor_start_timer -> nilfs_segctor_start_timer Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-03-14nilfs2: fix discrepancy in use of static specifierRyusuke Konishi
Two segbuf functions, nilfs_segbuf_write and nilfs_segbuf_wait, are declared with the static storage class specifier, but their implementations are not. This fixes the discrepancy. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-03-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits) init: Open /dev/console from rootfs mqueue: fix typo "failues" -> "failures" mqueue: only set error codes if they are really necessary mqueue: simplify do_open() error handling mqueue: apply mathematics distributivity on mq_bytes calculation mqueue: remove unneeded info->messages initialization mqueue: fix mq_open() file descriptor leak on user-space processes fix race in d_splice_alias() set S_DEAD on unlink() and non-directory rename() victims vfs: add NOFOLLOW flag to umount(2) get rid of ->mnt_parent in tomoyo/realpath hppfs can use existing proc_mnt, no need for do_kern_mount() in there Mirror MS_KERNMOUNT in ->mnt_flags get rid of useless vfsmount_lock use in put_mnt_ns() Take vfsmount_lock to fs/internal.h get rid of insanity with namespace roots in tomoyo take check for new events in namespace (guts of mounts_poll()) to namespace.c Don't mess with generic_permission() under ->d_lock in hpfs sanitize const/signedness for udf nilfs: sanitize const/signedness in dealing with ->d_name.name ... Fix up fairly trivial (famous last words...) conflicts in drivers/infiniband/core/uverbs_main.c and security/tomoyo/realpath.c
2010-03-03nilfs: sanitize const/signedness in dealing with ->d_name.nameAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-03-03nilfs really shouldn't slap struct dentry on stack...Al Viro
... especially when it only needs (and initializes) .d_name of it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-02-20nilfs2: add reader's lock for cno in nilfs_ioctl_syncJiro SEKIBA
This adds reader's lock for the_nilfs->cno in nilfs_ioctl_sync, for the_nilfs->cno should be proctected by segctor_sem when reading. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-02-18nilfs2: delete unnecessary condition in load_segment_summaryJiro SEKIBA
This is a trivial patch to remove unnecessary condition. load_segment_summary() checks crc of segment_summary OR crc of whole log data blocks based on boolean argument full_check. However, callers of the function pass only 1 as full_check, which means only whole log data blocks checking code is running all the time. This patch deletes the condition and full_check argument and also deletes enum 'NILFS_SEG_FAIL_CHECKSUM_SEGSUM' and corresponding case clause, for it is nolonger used anymore. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-02-13nilfs2: move iterator to write log into segment bufferRyusuke Konishi
This moves iterator to submit write requests for a series of logs into segbuf.c, and hides nilfs_segbuf_write() and nilfs_segbuf_wait() in the file. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-02-13nilfs2: get rid of s_dirt flag useRyusuke Konishi
This replaces s_dirt flag use in nilfs with a new flag added on the nilfs object. The s_dirt flag was used to indicate if sop->write_super() should be called, however the current version of nilfs does not use the callback. Thus, it can be replaced with the own flag. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Jiro SEKIBA <jir@unicus.jp>
2010-02-13nilfs2: get rid of nilfs_segctor_req structRyusuke Konishi
This will clean up nilfs_segctor_req struct and the obscure request argument passed among private methods of segment constructor. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-02-13nilfs2: delete unnecessary condition in nilfs_dat_translateJiro SEKIBA
This is a trivial patch to delete unnecessary condition in nilfs_dat_translate. nilfs_dat_translate() will asign translated address to *blocknrp if blocknrp is not NULL. However the condition is unneeded, because all callers of nilfs_dat_translate() pass blocknrp properly. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-02-13nilfs2: fix potential hang in nilfs_error on errors=remount-roRyusuke Konishi
nilfs_error() calls nilfs_detach_segment_constructor() if errors=remount-ro option is specified, and this may lead to a hang due to recursive locking of, for instance, nilfs->ns_segctor_sem and others. In this case, detaching segment constructor is not necessary because read-only flag is set to the filesystem and further writes are blocked. This fixes the potential hang issue by removing the nilfs_detach_segment_constructor() call from nilfs_error. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-02-13nilfs2: use mnt_want_write in ioctls where write access is neededRyusuke Konishi
A few nilfs2 ioctls need to ask for and then later release write access to the mount in order to avoid potential write to read-only mounts. This adds the missing mnt_want_write and mnt_drop_write in nilfs_ioctl_change_cpmode, nilfs_ioctl_delete_checkpoint, and nilfs_ioctl_clean_segments. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-02-13nilfs2: issue discard request after cleaning segmentsJiro SEKIBA
This adds a function to send discard requests for given array of segment numbers, and calls the function when garbage collection succeeded. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2010-01-31nilfs2: fix potential leak of dirty data on umountRyusuke Konishi
This fixes incorrect usage of nilfs_segctor_confirm() test function in nilfs_segctor_destroy(); nilfs_segctor_confirm() returns zero if the filesystem is not clean, so its use in nilfs_segctor_destroy() needs inversion. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-12-25nilfs2: Storage class should be before const qualifierTobias Klauser
The C99 specification states in section 6.11.5: The placement of a storage-class specifier other than at the beginning of the declaration specifiers in a declaration is an obsolescent feature. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-12-25nilfs2: trivial coding style fixJiro SEKIBA
This is a trivial style fix patch to mend errors/warnings reported by "checkpatch.pl --file". Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-12-17Revert "task_struct: make journal_info conditional"Linus Torvalds
This reverts commit e4c570c4cb7a95dbfafa3d016d2739bf3fdfe319, as requested by Alexey: "I think I gave a good enough arguments to not merge it. To iterate: * patch makes impossible to start using ext3 on EXT3_FS=n kernels without reboot. * this is done only for one pointer on task_struct" None of config options which define task_struct are tristate directly or effectively." Requested-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16switch nilfs2 to deactivate_locked_super()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-15task_struct: make journal_info conditionalHiroshi Shimamoto
journal_info in task_struct is used in journaling file system only. So introduce CONFIG_FS_JOURNAL_INFO and make it conditional. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-30nilfs2: separate wait function from nilfs_segctor_writeRyusuke Konishi
This separates wait function for submitted logs from the write function nilfs_segctor_write(). A new list of segment buffers "sc_write_logs" is added to hold logs under writing, and double buffering is partially applied to hide io latency. At this point, the double buffering is disabled for blocksize < pagesize because page dirty flag is turned off during write and dirty buffers are not properly collected for pages crossing over segments. To receive full benefit of the double buffering, further refinement is needed to move the io wait outside the lock section of log writer. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-30nilfs2: add iterator for segment buffersRyusuke Konishi
This adds a few iterator functions for segment buffers to make it easy to handle multiple series of logs. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-30nilfs2: hide nilfs_write_info struct in segment buffer codeRyusuke Konishi
Hides nilfs_write_info struct and nilfs_segbuf_prepare_write function in segbuf.c to simplify the interface of nilfs_segbuf_write function. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-30nilfs2: relocate io status variables to segment bufferRyusuke Konishi
This moves io status variables in nilfs_write_info struct to nilfs_segment_buffer struct. This is a preparation to hide nilfs_write_info in segment buffer code. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-29nilfs2: do not return io error for bio allocation failureRyusuke Konishi
Previously, log writer had possibility to set an io error flag on segments even in case of memory allocation failure. This fixes the issue. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-29nilfs2: use list_splice_tail or list_splice_tail_initRyusuke Konishi
This applies list_splice_tail (or list_splice_tail_init) operation instead of list_splice (or list_splice_init, respectively) to append a new list to tail of an existing list. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-27nilfs2: replace mark_inode_dirty as nilfs_mark_inode_dirtyJiro SEKIBA
Replace mark_inode_dirty() as nilfs_mark_inode_dirty() to reduce deep function calls. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-27nilfs2: delete mark_inode_dirty in nilfs_delete_entryJiro SEKIBA
Delete mark_inode_dirty() in nilfs_delete_entry() to reduce duplicate mark_inode_dirty() calls both in nilfs_rename() and nilfs_delete_entry(). Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-27nilfs2: delete mark_inode_dirty in nilfs_commit_chunkJiro SEKIBA
Delete mark_inode_dirty() in nilfs_commit_chunk(), for callers of nilfs_commit_chunk() will call equivalent mark_inode_dirty() after calling nilfs_commit_chunk(). Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-27nilfs2: change return type of nilfs_commit_chunkJiro SEKIBA
change return type of nilfs_commit_chunk() as void from int, for nilfs_set_file_dirty() usually does not return error. This is an intermediate patch to reduce mark_inode_dirty() in nilfs_commit_chunk(). Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-27nilfs2: split nilfs_unlink as nilfs_do_unlink and nilfs_unlinkJiro SEKIBA
Split nilfs_unlink() to reduce nested transaction and duplicate mark_inode_dirty() calls when calling nilfs_unlink() from nilfs_rmdir(). nilfs_do_unlink() is an actual unlink functionality which is not in transaction and does not call mark_inode_dirty() for dentry argument. nilfs_unlink() is a wrapper function for do_nilfs_unlink() with transaction and mark_inode_dirty() for dentry argument. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-27nilfs2: delete redundant mark_inode_dirtyJiro SEKIBA
delete redundant mark_inode_dirty() calls Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-27nilfs2: expand inode_inc_link_count and inode_dec_link_countJiro SEKIBA
This is an intermidiate patch to reduce redandunt mark_inode_dirty() calls by calling inode_inc_link_count() and inode_dec_link_count() functions. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-27nilfs2: delete mark_inode_dirty from nilfs_set_linkJiro SEKIBA
Delete mark_inode_dirty() from nilfs_set_link() to reduce redundant mark_inode_dirty() calls in caller of nilfs_set_link(). Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-27nilfs2: delete mark_inode_dirty in nilfs_new_inodeJiro SEKIBA
It is redundant to call mark_inode_dirty() in nilfs_new_inode() because all caller of nilfs_new_inode() will call mark_inode_dirty() after calling nilfs_new_inode() directly or indirectly in transaction. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-20nilfs2: add norecovery mount optionRyusuke Konishi
This adds "norecovery" mount option which disables temporal write access to read-only mounts or snapshots during mount/recovery. Without this option, write access will be even performed for those types of mounts; the temporal write access is needed to mount root file system read-only after an unclean shutdown. This option will be helpful when user wants to prevent any write access to the device. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Eric Sandeen <sandeen@redhat.com>
2009-11-20nilfs2: add helper to get if volume is in a valid stateRyusuke Konishi
This adds a helper function, nilfs_valid_fs() which returns if nilfs is in a valid state or not. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-20nilfs2: move recovery completion into load_nilfs functionRyusuke Konishi
Although mount recovery of nilfs is integrated in load_nilfs() procedure, the completion of recovery was isolated from the procedure and performed at the end of the fill_super routine. This was somewhat confusing since the recovery is needed for the nilfs object, not for a super block instance. To resolve the inconsistency, this will integrate the recovery completion into load_nilfs(). Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-20nilfs2: apply readahead for recovery on mountRyusuke Konishi
This inserts readahead in the recovery code. The readahead request is issued per segment while searching the latest super root block. This will shorten mount time after unclean unmount. A measurement shows the recovery time was reduced by more than 60 percent: e.g. real 0m11.586s -> 0m3.918s (x 2.96) Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-20nilfs2: clean up get/put function of a segment usageRyusuke Konishi
This eliminates obsolete nilfs_get_sufile_get_segment_usage() and nilfs_set_sufile_segment_usage() from sufile. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-20nilfs2: move routine to set segment usage into sufileRyusuke Konishi
This adds nilfs_sufile_set_segment_usage() function in sufile to replace direct access to the sufile metadata in log writer code. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-20nilfs2: move routine marking segment usage dirty into sufileRyusuke Konishi
This adds nilfs_sufile_mark_dirty() function in sufile to replace nilfs_touch_segusage() function in log writer code. This is a preparation for the further cleanup which will move out low level sufile operations in the log writer. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>