linux/fs/nilfs2
Vyacheslav Dubeyko aebe17f684 nilfs2: add /sys/fs/nilfs2/features group
This patchset implements creation of sysfs groups and attributes with
the purpose to show NILFS2 volume details, internal state of the driver
and to manage internal state of NILFS2 driver.

Sysfs is a virtual file system that exports information about devices
and drivers from the kernel device model to user space, and is also used
for configuration.  NILFS2 is a complex file system that has segctor
thread, GC thread, checkpoint/snapshot model and so on.  Sysfs namespace
provides native and easy way for: (1) getting info and statistics about
volume state; (2) getting info and configuration of internal subsystems
(segctor thread); (3) snapshots management.

Suggested patchset provides basis for managing segctor thread behaviour
and manipulation by snapshots.  Currently, it informs only about segctor
thread's internal parameters and about mounted snapshots.  But sysfs
interface can provide easy and simple way for deep management of segctor
thread and snapshots.

This patchset provides opportunity to manage interval of periodical
update of superblock (in seconds).  Default value is 10 seconds.  Now a
user can increase this value by means of
nilfs2/<device>/superblock/sb_update_frequency attribute in the case of
necessity.

Also the patchset provides opportunity to get information easily about
key volumes's parameters (free blocks, superblock write count,
superblock update frequency, latest segment info, dirty data blocks
count, count of clean segments, count of dirty segments and so on) in
real time manner.  Such information can be used in scripts for subtle
management of filesystem.

Implemented functionality creates such groups:
(1) /sys/fs/nilfs2 - root group
(2) /sys/fs/nilfs2/features - group contains attributes that describe NILFS
file system driver features
(3) /sys/fs/nilfs2/<device> - group contains attributes that describe file
system partition's details
(4) /sys/fs/nilfs2/<device>/superblock - group contains attributes that describe
superblock's details
(5) /sys/fs/nilfs2/<device>/segctor - group contains attributes that describe
segctor thread activity details
(6) /sys/fs/nilfs2/<device>/segments - group contains attributes that describe
details about volume's segments
(7) /sys/fs/nilfs2/<device>/checkpoints - group contains attributes that describe
details about volume's checkpoints
(8) /sys/fs/nilfs2/<device>/mounted_snapshots - group contains group for every
mounted snapshot
(9) /sys/fs/nilfs2/<device>/mounted_snapshots/<snapshot> - group contains
details about mounted snapshot

This patch (of 9):

This patch adds code of creation /sys/fs/nilfs2 group and
/sys/fs/nilfs2/features group.

The features group contains attributes that describe NILFS
file system driver features:
(1) revision - show current revision of NILFS file system driver.

There are two formats of timestamp output - seconds and human-readable
format.  Every showed timestamp has two sysfs files (time-<xxx> and
time-<xxx>-secs).  One sysfs file (time-<xxx>) shows time in
human-readable format.  Another sysfs file (time-<xxx>-secs) shows time in
seconds.

It was reported by Michael Semon that timestamp output in human-readable
format should be changed from "2014-4-12 14:5:38" to "2014-04-12
14:05:38".  Second version of the patch fixes this issue.

Reported-by: Michael L. Semon <mlsemon35@gmail.com>
Signed-off-by: Vyacheslav Dubeyko <Vyacheslav.Dubeyko@hgst.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:20 -07:00
..
Kconfig fs/nilfs2: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:39:04 -08:00
Makefile nilfs2: get rid of GCDAT inode 2010-10-23 09:24:38 +09:00
alloc.c nilfs2: implement calculation of free inodes count 2013-07-03 16:08:01 -07:00
alloc.h nilfs2: implement calculation of free inodes count 2013-07-03 16:08:01 -07:00
bmap.c nilfs2: get rid of NILFS_I_NILFS 2011-05-10 22:21:56 +09:00
bmap.h nilfs2: add omitted comments for different structures in driver implementation 2012-07-30 17:25:19 -07:00
btnode.c nilfs2: use mark_buffer_dirty to mark btnode or meta data dirty 2011-05-10 22:21:57 +09:00
btnode.h nilfs2: add omitted comments for different structures in driver implementation 2012-07-30 17:25:19 -07:00
btree.c nilfs2: fix missing block address termination in btree node shrinking 2011-06-11 15:51:15 +09:00
btree.h nilfs2: get rid of nilfs_bmap_union 2010-07-23 10:02:14 +09:00
cpfile.c nilfs2: verify metadata sizes read from disk 2014-04-03 16:21:26 -07:00
cpfile.h nilfs2: use iget for all metadata files 2010-10-23 09:24:38 +09:00
dat.c nilfs2: verify metadata sizes read from disk 2014-04-03 16:21:26 -07:00
dat.h nilfs2: use iget for all metadata files 2010-10-23 09:24:38 +09:00
dir.c [readdir] convert nilfs2 2013-06-29 12:56:36 +04:00
direct.c nilfs2: record used amount of each checkpoint in checkpoint list 2011-03-08 14:58:31 +09:00
direct.h nilfs2: get rid of nilfs_bmap_union 2010-07-23 10:02:14 +09:00
export.h nilfs2: add omitted comments for different structures in driver implementation 2012-07-30 17:25:19 -07:00
file.c write_iter variants of {__,}generic_file_aio_write() 2014-05-06 17:38:00 -04:00
gcinode.c nilfs2: ensure proper cache clearing for gc-inodes 2012-06-20 14:39:35 -07:00
ifile.c ] nilfs2: use atomic64_t type for inodes_count and blocks_count fields in nilfs_root struct 2013-07-03 16:08:01 -07:00
ifile.h nilfs2: implement calculation of free inodes count 2013-07-03 16:08:01 -07:00
inode.c switch {__,}blockdev_direct_IO() to iov_iter 2014-05-06 17:32:46 -04:00
ioctl.c nilfs2: add FITRIM ioctl support for nilfs2 2014-04-03 16:21:26 -07:00
mdt.c nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption 2013-04-30 17:04:04 -07:00
mdt.h nilfs2: add omitted comments for different structures in driver implementation 2012-07-30 17:25:19 -07:00
namei.c fs: encode_fh: return FILEID_INVALID if invalid fid_type 2013-02-26 02:46:10 -05:00
nilfs.h nilfs2: drop vmtruncate 2012-12-20 18:40:54 -05:00
page.c nilfs2: fix issue with race condition of competition between segments for dirty blocks 2013-09-30 14:31:02 -07:00
page.h nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption 2013-04-30 17:04:04 -07:00
recovery.c nilfs2: drop vmtruncate 2012-12-20 18:40:54 -05:00
segbuf.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
segbuf.h nilfs2: get rid of macros for segment summary information 2010-07-23 10:02:09 +09:00
segment.c nilfs2: fix segctor bug that causes file system corruption 2014-01-15 14:19:42 +07:00
segment.h nilfs2: get rid of private page allocator 2011-05-10 22:21:44 +09:00
sufile.c nilfs2: verify metadata sizes read from disk 2014-04-03 16:21:26 -07:00
sufile.h nilfs2: add nilfs_sufile_trim_fs to trim clean segs 2014-04-03 16:21:25 -07:00
super.c fs: push sync_filesystem() down to the file system's remount_fs() 2014-03-13 10:14:33 -04:00
sysfs.c nilfs2: add /sys/fs/nilfs2/features group 2014-08-08 15:57:20 -07:00
sysfs.h nilfs2: add /sys/fs/nilfs2/features group 2014-08-08 15:57:20 -07:00
the_nilfs.c nilfs2: verify metadata sizes read from disk 2014-04-03 16:21:26 -07:00
the_nilfs.h ] nilfs2: use atomic64_t type for inodes_count and blocks_count fields in nilfs_root struct 2013-07-03 16:08:01 -07:00