Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753452Ab2JFSZn (ORCPT ); Sat, 6 Oct 2012 14:25:43 -0400 Received: from mail-da0-f46.google.com ([209.85.210.46]:45867 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751968Ab2JFSZl (ORCPT ); Sat, 6 Oct 2012 14:25:41 -0400 Message-ID: <1349547932.12699.49.camel@kjgkr> Subject: Re: [PATCH 02/16] f2fs: add on-disk layout From: Jaegeuk Kim To: Martin Steigerwald Cc: linux-kernel@vger.kernel.org, =?euc-kr?Q?=B1=E8=C0=E7=B1=D8?= , viro@zeniv.linux.org.uk, "'Theodore Ts'o'" , gregkh@linuxfoundation.org, chur.lee@samsung.com, cm224.lee@samsung.com, jooyoung.hwang@samsung.com Date: Sun, 07 Oct 2012 03:25:32 +0900 In-Reply-To: <201210051946.21451.Martin@lichtvoll.de> References: <000901cda2f0$7d773eb0$7865bc10$%kim@samsung.com> (sfid-20121005_184512_086765_45BFD6B3) <201210051946.21451.Martin@lichtvoll.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 8bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4071 Lines: 93 2012-10-05 (금), 19:46 +0200, Martin Steigerwald: > Am Freitag, 5. Oktober 2012 schrieb 김재극: > > This adds a header file describing the on-disk layout of f2fs. > > > > Signed-off-by: Changman Lee > > Signed-off-by: Chul Lee > > Signed-off-by: Jaegeuk Kim > > --- > > include/linux/f2fs_fs.h | 359 +++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 359 insertions(+) > > create mode 100644 include/linux/f2fs_fs.h > > > > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h > > new file mode 100644 > > index 0000000..b17eeec > > --- /dev/null > > +++ b/include/linux/f2fs_fs.h > > @@ -0,0 +1,359 @@ > > +/** > > + * include/linux/f2fs_fs.h > […] > > +/* > > + * For superblock > > + */ > > +struct f2fs_super_block { > > + __le32 magic; /* Magic Number */ > > + __le16 major_ver; /* Major Version */ > > + __le16 minor_ver; /* Minor Version */ > > + __le32 log_sectorsize; /* log2 (Sector size in bytes) */ > > + __le32 log_sectors_per_block; /* log2 (Number of sectors per block */ > > + __le32 log_blocksize; /* log2 (Block size in bytes) */ > > + __le32 log_blocks_per_seg; /* log2 (Number of blocks per segment) */ > > + __le32 log_segs_per_sec; /* log2 (Number of segments per section) */ > > + __le32 secs_per_zone; /* Number of sections per zone */ > > + __le32 checksum_offset; /* Checksum position in this super block */ > > + __le64 block_count; /* Total number of blocks */ > > + __le32 section_count; /* Total number of sections */ > > + __le32 segment_count; /* Total number of segments */ > > + __le32 segment_count_ckpt; /* Total number of segments > > + in Checkpoint area */ > > + __le32 segment_count_sit; /* Total number of segments > > + in Segment information table */ > > + __le32 segment_count_nat; /* Total number of segments > > + in Node address table */ > > + /*Total number of segments in Segment summary area */ > > + __le32 segment_count_ssa; > > + /* Total number of segments in Main area */ > > + __le32 segment_count_main; > > + __le32 failure_safe_block_distance; > > + __le64 segment0_blkaddr; /* Start block address of Segment 0 */ > > + __le64 start_segment_checkpoint; /* Start block address of ckpt */ > > + __le64 sit_blkaddr; /* Start block address of SIT */ > > + __le64 nat_blkaddr; /* Start block address of NAT */ > > + __le64 ssa_blkaddr; /* Start block address of SSA */ > > + __le64 main_blkaddr; /* Start block address of Main area */ > > + __le32 root_ino; /* Root directory inode number */ > > + __le32 node_ino; /* node inode number */ > > + __le32 meta_ino; /* meta inode number */ > > + __le32 volume_serial_number; /* VSN is optional field */ > > + __le16 volume_name[8]; /* Volume Name. 8 unicode characters */ > > +} __packed; > > Any reason why volume label is that short? > Noop. > If superblock can occupy up to 4096 bytes, i.e. a block, I think a bit > more space for volume label would fit in there. I count 128 bytes up > to volume_name. Do other structures need to fit in superblock as well? > I think it cannot be a problem to give more bytes to the name space. I'll do this. > I believe users easily can hit a limit of 8 unicode characters even for > USB sticks and SD cards. > Nice to see a flash friendly filesystem which seems to take lots of the > stuff in account I read at Linaro website about flash devices. > Thank you. -- Jaegeuk Kim Samsung -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/