Hi, At Mon, 16 May 2011 18:05:13 +0900, Ryusuke Konishi wrote: > > This is an experimental patchset which adds new ioctl commands for > finding differences between two checkpoints (snapshots) efficiently. > > One of the commands is NILFS_IOCTL_COMPARE_CHECKPOINTS and another is > NILFS_IOCTL_INO_LOOKUP. > > The NILFS_IOCTL_COMPARE_CHECKPOINT command enumerates changed inodes > between two checkpoints. It compares two versions of b-trees managing > blocks of "ifile" instead of traversing namespace and comparing all > pairs of inodes. > > It gathers up inode numbers of changed inodes, but it's not efficient > to find a pathname of inode at userspace from its inode number. So, > the NILFS_IOCTL_INO_LOOKUP command is included to make it faster and > easier -- it makes up a pathname of an inode in the past filesystem > tree searching directories bottom up. > > > With this api, users or tools can know which inodes were changed, > created, or deleted and how they were modified. This is intended to > be used for online backup, realtime remote replication, or quickly > rebuilding search index against numerous versions of a filesystem > provided by nilfs. Kernel already has some notification mechanisms > for these purposes, but they don't suit for extract changes later on. > > > A utility program for examining these ioctl commands is available on > "diff" branch of the following git tree: > > http://git.nilfs.org/nilfs2-utils-devel.git I can't find "diff" branch from the repository nor retrieve the branch. Is something wrong with my local or the remote repository? $ git remote -v devel http://git.nilfs.org/nilfs2-utils-devel.git origin http://git.nilfs.org/nilfs2-utils.git $ git branch -r devel/fixes devel/fsck0 devel/fsck0-2010-05-16 devel/master devel/next origin/HEAD origin/master $ git fetch http://git.nilfs.org/nilfs2-utils-devel.git diff:diff fatal: Couldn't find remote ref diff thanks, regards > It experimentally adds "nilfs-diff" program to nilfs-utils. The usage > of this program is as follows: > > > # nilfs-diff [option] [device] cno1..cno2 > > "nilfs-diff" displays appended files or directories as below: > > + /aaa/bbb > + /aaa/bbb/ccc > > Deleted files are displayed like: > > - /aaa/xxx > > Modified or moved files are: > > M /aaa/bbb/file-000.txt > R /aaa/bbb/file-123.txt -> /aaa/file-123.txt > > > Unfortunately, the NILFS_IOCTL_INO_LOOKUP command needs disk format > change since it has to keep parent inode numbers for each on-disk > inode. > > This patchset uses an unused pad field in disk inode, so this feature > is only available for new filesystems created with updated mkfs.nilfs2 > tool. > > In addition, this patchset has a few important limitations and does > not suit for practical use. First, hard links are not supported (only > one parent inode number is recorded in an inode). And, inode number > of parent inodes are truncated to 32-bit width from the original > 64-bit value when being stored to disk. > > So, this is very experimetal, and I have no plan to send them upstream > at this moment. > > To make it practical, parent inode number should be recorded in disk > more nicely. I guess a disk format change would be necessary for > that. > > If anyone have comments, please let me know. > > > Thanks, > Ryusuke Konishi > -- > Ryusuke Konishi (9): > nilfs2: add separable lookup routines to direct/btree mappings > nilfs2: add comparison function of two block mappings > nilfs2: add helper functions to get type of blocks on ifile > nilfs2: add ifile method to find and get modified inodes > nilfs2: add ioctl to compare two checkpoints and get their changes > nilfs2: store parent inode number in disk inode > nilfs2: add routine to find directory entry from inode number > nilfs2: add pathname lookup routine from inode number > nilfs2: add ioctl to lookup pathname of inode > > fs/nilfs2/alloc.c | 35 ++++++++- > fs/nilfs2/alloc.h | 10 +++ > fs/nilfs2/bmap.c | 154 +++++++++++++++++++++++++++++++++++++ > fs/nilfs2/bmap.h | 20 +++++ > fs/nilfs2/btree.c | 134 ++++++++++++++++++++++++++++++++ > fs/nilfs2/dir.c | 60 +++++++++++++++ > fs/nilfs2/direct.c | 49 ++++++++++++ > fs/nilfs2/ifile.c | 184 +++++++++++++++++++++++++++++++++++++++++++++ > fs/nilfs2/ifile.h | 20 +++++ > fs/nilfs2/inode.c | 131 +++++++++++++++++++++++++++++++- > fs/nilfs2/ioctl.c | 135 +++++++++++++++++++++++++++++++++ > fs/nilfs2/namei.c | 97 ++++++++++++++++++++++++ > fs/nilfs2/nilfs.h | 14 ++++ > fs/nilfs2/super.c | 49 ++++++++++++ > include/linux/nilfs2_fs.h | 64 +++++++++++++++- > 15 files changed, 1148 insertions(+), 8 deletions(-) > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > -- Jiro SEKIBA <jir@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
