-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
yaml --- r: 142747 b: refs/heads/master c: 6a5d263 h: refs/heads/master i: 142745: af9b9f2 142743: 415cc2b v: v3
- Loading branch information
Linus Torvalds
committed
Apr 7, 2009
1 parent
ac98415
commit bfcadac
Showing
627 changed files
with
64,137 additions
and
20,247 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,2 +1,2 @@ | ||
| --- | ||
| refs/heads/master: ffcd7dca3ab78f9f425971756e5e90024157f6be | ||
| refs/heads/master: 6a5d263866d699ebf6843105497afc86ee53de5b |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,200 @@ | ||
| NILFS2 | ||
| ------ | ||
|
|
||
| NILFS2 is a log-structured file system (LFS) supporting continuous | ||
| snapshotting. In addition to versioning capability of the entire file | ||
| system, users can even restore files mistakenly overwritten or | ||
| destroyed just a few seconds ago. Since NILFS2 can keep consistency | ||
| like conventional LFS, it achieves quick recovery after system | ||
| crashes. | ||
|
|
||
| NILFS2 creates a number of checkpoints every few seconds or per | ||
| synchronous write basis (unless there is no change). Users can select | ||
| significant versions among continuously created checkpoints, and can | ||
| change them into snapshots which will be preserved until they are | ||
| changed back to checkpoints. | ||
|
|
||
| There is no limit on the number of snapshots until the volume gets | ||
| full. Each snapshot is mountable as a read-only file system | ||
| concurrently with its writable mount, and this feature is convenient | ||
| for online backup. | ||
|
|
||
| The userland tools are included in nilfs-utils package, which is | ||
| available from the following download page. At least "mkfs.nilfs2", | ||
| "mount.nilfs2", "umount.nilfs2", and "nilfs_cleanerd" (so called | ||
| cleaner or garbage collector) are required. Details on the tools are | ||
| described in the man pages included in the package. | ||
|
|
||
| Project web page: http://www.nilfs.org/en/ | ||
| Download page: http://www.nilfs.org/en/download.html | ||
| Git tree web page: http://www.nilfs.org/git/ | ||
| NILFS mailing lists: http://www.nilfs.org/mailman/listinfo/users | ||
|
|
||
| Caveats | ||
| ======= | ||
|
|
||
| Features which NILFS2 does not support yet: | ||
|
|
||
| - atime | ||
| - extended attributes | ||
| - POSIX ACLs | ||
| - quotas | ||
| - writable snapshots | ||
| - remote backup (CDP) | ||
| - data integrity | ||
| - defragmentation | ||
|
|
||
| Mount options | ||
| ============= | ||
|
|
||
| NILFS2 supports the following mount options: | ||
| (*) == default | ||
|
|
||
| barrier=on(*) This enables/disables barriers. barrier=off disables | ||
| it, barrier=on enables it. | ||
| errors=continue(*) Keep going on a filesystem error. | ||
| errors=remount-ro Remount the filesystem read-only on an error. | ||
| errors=panic Panic and halt the machine if an error occurs. | ||
| cp=n Specify the checkpoint-number of the snapshot to be | ||
| mounted. Checkpoints and snapshots are listed by lscp | ||
| user command. Only the checkpoints marked as snapshot | ||
| are mountable with this option. Snapshot is read-only, | ||
| so a read-only mount option must be specified together. | ||
| order=relaxed(*) Apply relaxed order semantics that allows modified data | ||
| blocks to be written to disk without making a | ||
| checkpoint if no metadata update is going. This mode | ||
| is equivalent to the ordered data mode of the ext3 | ||
| filesystem except for the updates on data blocks still | ||
| conserve atomicity. This will improve synchronous | ||
| write performance for overwriting. | ||
| order=strict Apply strict in-order semantics that preserves sequence | ||
| of all file operations including overwriting of data | ||
| blocks. That means, it is guaranteed that no | ||
| overtaking of events occurs in the recovered file | ||
| system after a crash. | ||
|
|
||
| NILFS2 usage | ||
| ============ | ||
|
|
||
| To use nilfs2 as a local file system, simply: | ||
|
|
||
| # mkfs -t nilfs2 /dev/block_device | ||
| # mount -t nilfs2 /dev/block_device /dir | ||
|
|
||
| This will also invoke the cleaner through the mount helper program | ||
| (mount.nilfs2). | ||
|
|
||
| Checkpoints and snapshots are managed by the following commands. | ||
| Their manpages are included in the nilfs-utils package above. | ||
|
|
||
| lscp list checkpoints or snapshots. | ||
| mkcp make a checkpoint or a snapshot. | ||
| chcp change an existing checkpoint to a snapshot or vice versa. | ||
| rmcp invalidate specified checkpoint(s). | ||
|
|
||
| To mount a snapshot, | ||
|
|
||
| # mount -t nilfs2 -r -o cp=<cno> /dev/block_device /snap_dir | ||
|
|
||
| where <cno> is the checkpoint number of the snapshot. | ||
|
|
||
| To unmount the NILFS2 mount point or snapshot, simply: | ||
|
|
||
| # umount /dir | ||
|
|
||
| Then, the cleaner daemon is automatically shut down by the umount | ||
| helper program (umount.nilfs2). | ||
|
|
||
| Disk format | ||
| =========== | ||
|
|
||
| A nilfs2 volume is equally divided into a number of segments except | ||
| for the super block (SB) and segment #0. A segment is the container | ||
| of logs. Each log is composed of summary information blocks, payload | ||
| blocks, and an optional super root block (SR): | ||
|
|
||
| ______________________________________________________ | ||
| | |SB| | Segment | Segment | Segment | ... | Segment | | | ||
| |_|__|_|____0____|____1____|____2____|_____|____N____|_| | ||
| 0 +1K +4K +8M +16M +24M +(8MB x N) | ||
| . . (Typical offsets for 4KB-block) | ||
| . . | ||
| .______________________. | ||
| | log | log |... | log | | ||
| |__1__|__2__|____|__m__| | ||
| . . | ||
| . . | ||
| . . | ||
| .______________________________. | ||
| | Summary | Payload blocks |SR| | ||
| |_blocks__|_________________|__| | ||
|
|
||
| The payload blocks are organized per file, and each file consists of | ||
| data blocks and B-tree node blocks: | ||
|
|
||
| |<--- File-A --->|<--- File-B --->| | ||
| _______________________________________________________________ | ||
| | Data blocks | B-tree blocks | Data blocks | B-tree blocks | ... | ||
| _|_____________|_______________|_____________|_______________|_ | ||
|
|
||
|
|
||
| Since only the modified blocks are written in the log, it may have | ||
| files without data blocks or B-tree node blocks. | ||
|
|
||
| The organization of the blocks is recorded in the summary information | ||
| blocks, which contains a header structure (nilfs_segment_summary), per | ||
| file structures (nilfs_finfo), and per block structures (nilfs_binfo): | ||
|
|
||
| _________________________________________________________________________ | ||
| | Summary | finfo | binfo | ... | binfo | finfo | binfo | ... | binfo |... | ||
| |_blocks__|___A___|_(A,1)_|_____|(A,Na)_|___B___|_(B,1)_|_____|(B,Nb)_|___ | ||
|
|
||
|
|
||
| The logs include regular files, directory files, symbolic link files | ||
| and several meta data files. The mata data files are the files used | ||
| to maintain file system meta data. The current version of NILFS2 uses | ||
| the following meta data files: | ||
|
|
||
| 1) Inode file (ifile) -- Stores on-disk inodes | ||
| 2) Checkpoint file (cpfile) -- Stores checkpoints | ||
| 3) Segment usage file (sufile) -- Stores allocation state of segments | ||
| 4) Data address translation file -- Maps virtual block numbers to usual | ||
| (DAT) block numbers. This file serves to | ||
| make on-disk blocks relocatable. | ||
|
|
||
| The following figure shows a typical organization of the logs: | ||
|
|
||
| _________________________________________________________________________ | ||
| | Summary | regular file | file | ... | ifile | cpfile | sufile | DAT |SR| | ||
| |_blocks__|_or_directory_|_______|_____|_______|________|________|_____|__| | ||
|
|
||
|
|
||
| To stride over segment boundaries, this sequence of files may be split | ||
| into multiple logs. The sequence of logs that should be treated as | ||
| logically one log, is delimited with flags marked in the segment | ||
| summary. The recovery code of nilfs2 looks this boundary information | ||
| to ensure atomicity of updates. | ||
|
|
||
| The super root block is inserted for every checkpoints. It includes | ||
| three special inodes, inodes for the DAT, cpfile, and sufile. Inodes | ||
| of regular files, directories, symlinks and other special files, are | ||
| included in the ifile. The inode of ifile itself is included in the | ||
| corresponding checkpoint entry in the cpfile. Thus, the hierarchy | ||
| among NILFS2 files can be depicted as follows: | ||
|
|
||
| Super block (SB) | ||
| | | ||
| v | ||
| Super root block (the latest cno=xx) | ||
| |-- DAT | ||
| |-- sufile | ||
| `-- cpfile | ||
| |-- ifile (cno=c1) | ||
| |-- ifile (cno=c2) ---- file (ino=i1) | ||
| : : |-- file (ino=i2) | ||
| `-- ifile (cno=xx) |-- file (ino=i3) | ||
| : : | ||
| `-- file (ino=yy) | ||
| ( regular file, directory, or symlink ) | ||
|
|
||
| For detail on the format of each file, please see include/linux/nilfs2_fs.h. |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,36 @@ | ||
| Kernel driver g760a | ||
| =================== | ||
|
|
||
| Supported chips: | ||
| * Global Mixed-mode Technology Inc. G760A | ||
| Prefix: 'g760a' | ||
| Datasheet: Publicly available at the GMT website | ||
| http://www.gmt.com.tw/datasheet/g760a.pdf | ||
|
|
||
| Author: Herbert Valerio Riedel <hvr@gnu.org> | ||
|
|
||
| Description | ||
| ----------- | ||
|
|
||
| The GMT G760A Fan Speed PWM Controller is connected directly to a fan | ||
| and performs closed-loop control of the fan speed. | ||
|
|
||
| The fan speed is programmed by setting the period via 'pwm1' of two | ||
| consecutive speed pulses. The period is defined in terms of clock | ||
| cycle counts of an assumed 32kHz clock source. | ||
|
|
||
| Setting a period of 0 stops the fan; setting the period to 255 sets | ||
| fan to maximum speed. | ||
|
|
||
| The measured fan rotation speed returned via 'fan1_input' is derived | ||
| from the measured speed pulse period by assuming again a 32kHz clock | ||
| source and a 2 pulse-per-revolution fan. | ||
|
|
||
| The 'alarms' file provides access to the two alarm bits provided by | ||
| the G760A chip's status register: Bit 0 is set when the actual fan | ||
| speed differs more than 20% with respect to the programmed fan speed; | ||
| bit 1 is set when fan speed is below 1920 RPM. | ||
|
|
||
| The g760a driver will not update its values more frequently than every | ||
| other second; reading them more often will do no harm, but will return | ||
| 'old' values. |
Oops, something went wrong.