linux-stable.git/include/linux/nilfs2_fs.h, branch linux-2.6.38.y

nilfs2: change license of exported header file

2010-10-23T00:24:39+00:00

This allows other projects to carry copies of the header file related
to ABI and disk format (i.e. "nilfs2_fs.h") without it or distributors
having to worry about effects on the project's overall license terms.
It's also desired for switching the license of nilfs library to LGPL.

Jiro SEKIBA pointed out these license issues (Message-ID:
<87tylo7msw.wl%jir@sekiba.com>), and he suggested switching license of
the library and nilfs2_fs.h to GNU Lesser General Public License.  We
take in his suggestion to avoid the license issues.

Signed-off-by: Ryusuke Konishi 
Cc: Jiro SEKIBA 
Cc: linux-nilfs

nilfs2: get rid of snapshot mount flag

2010-10-23T00:24:36+00:00

This flag is a fake used to distinguish type of super block instance.
And, it got obsolete by the unification of sb.

Signed-off-by: Ryusuke Konishi

nilfs2: keep zero value in i_cno except for gc-inodes

2010-10-23T00:24:33+00:00

On-memory inode structures of nilfs have a member "i_cno" which stores
a checkpoint number related to the inode.  For gc-inodes, this field
indicates version of data each gc-inode caches for GC.  Log writer
temporarily uses "i_cno" to transfer the latest checkpoint number.

This stops the latter use and lets only gc-inodes use it.

The purpose of this patch is to allow the successive change use
"i_cno" for inode lookup.

Signed-off-by: Ryusuke Konishi

nilfs2: accept future revisions

2010-10-23T00:24:33+00:00

Compatibility of nilfs partitions is now managed with three feature
sets.  This changes old compatibility check with revision number so
that it can accept future revisions.

Note that we can stop support of experimental versions of nilfs that
doesn't know the feature sets by incrementing NILFS_CURRENT_REV.  We
don't have to do it soon, but it would be a possible option whenever
the need arises.

Signed-off-by: Ryusuke Konishi

nilfs2: reject filesystem with unsupported block size

2010-07-25T14:29:21+00:00

This inserts sanity check that refuses to mount a filesystem with
unsupported block size.

Previously, kernel code of nilfs was looking only limitation of
devices though mkfs.nilfs2 limits the range of block sizes; there was
no check that prevents rec_len overflow with larger block sizes.

With this change, block sizes larger than 64KB or smaller than 1KB
will get rejected explicitly by kernel.

Signed-off-by: Ryusuke Konishi

nilfs2: avoid rec_len overflow with 64KB block size

2010-07-25T11:46:43+00:00

With 64KB blocksize, a directory entry can have size 64KB which does
not fit into 16 bits we have for entry length.  So this patch stores
0xffff instead and converts value when read from / written to disk.

Nilfs derives its directory implementation from ext2 filesystem, and
this draws upon the corresponding change on ext2.

Signed-off-by: Ryusuke Konishi

nilfs2: add feature set fields to super block

2010-07-23T01:02:16+00:00

This adds three new fields to nilfs_super_block structure, compatible
feature set, readonly-compatible feature set, and incompatible feature
set in order to prepare for future disk format modifications.

The role of these fields conforms to those of ext3 or other
filesystems.  Most important flags are the incompatible feature set;
it is used to refuse to mount the filesystem which sets an
incompatible feature the kernel doesn't know about.

Signed-off-by: Ryusuke Konishi

nilfs2: clarify byte offset in super block format

2010-07-23T01:02:16+00:00

This inserts comments indicating hexadecimal offset in declaration of
nilfs_super_block structure so that people can know offset of its
fields without counting from the head.

Signed-off-by: Ryusuke Konishi

nilfs2: enlarge s_volume_name member in nilfs_super_block

2010-05-10T02:32:33+00:00

Current s_volume_name has 16 bytes, which is too small as modern filesystem.

s_last_mounted resides just after s_volume_name and has 64 bytes.

s_last_mounted is historically came from ext2, but not used in nilfs2 at all.
Deleting s_last_mounted member and merging that space with s_volume_name
enlarge s_volume_name upto 80 bytes for volume label.

When user land tools see the old header for new disk, it will just ignore
additional bytes stored in s_last_mounted.  While, old disk format has only
16 bytes label, it doesn't affects in case seeing the new header for old disk.

Signed-off-by: Jiro SEKIBA 
Signed-off-by: Ryusuke Konishi

nilfs2: insert checkpoint number in segment summary header

2010-05-10T02:32:31+00:00

This adds a field to record the latest checkpoint number in the
nilfs_segment_summary structure.  This will help to recover the latest
checkpoint number from logs on disk.  This field is intended for
crucial cases in which super blocks have lost pointer to the latest
log.

Even though this will change the disk format, both backward and
forward compatibility is preserved by a size field prepared in the
segment summary header.

Signed-off-by: Ryusuke Konishi