Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753027Ab0GZA00 (ORCPT ); Sun, 25 Jul 2010 20:26:26 -0400 Received: from xenotime.net ([72.52.115.56]:58639 "HELO xenotime.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752963Ab0GZA0Z (ORCPT ); Sun, 25 Jul 2010 20:26:25 -0400 Date: Sun, 25 Jul 2010 17:26:18 -0700 From: Randy Dunlap To: Lubomir Rintel Cc: Al Viro , Linux Kernel Mailing List , Andrew Morton , Christoph Hellwig Subject: Re: [PATCH] V7: Add support for non-PDP11 v7 filesystems Message-Id: <20100725172618.25e37c35.rdunlap@xenotime.net> In-Reply-To: <1280098756-26522-1-git-send-email-lkundrak@v3.sk> References: <20100724135128.GA11645@ZenIV.linux.org.uk> <1280098756-26522-1-git-send-email-lkundrak@v3.sk> Organization: YPO4 X-Mailer: Sylpheed 2.7.1 (GTK+ 2.16.6; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4397 Lines: 142 On Mon, 26 Jul 2010 00:59:16 +0200 Lubomir Rintel wrote: > This adds byte order autodetection (of PDP-11 and LE filesystems). > No attempt is made to detect big-endian filesystems -- were there any? > Tested with PDP-11 v7 filesystems and PC-IX maintenance floppy. > > Cc: Christoph Hellwig > Cc: Al Viro > Signed-off-by: Lubomir Rintel > --- > fs/sysv/super.c | 74 +++++++++++++++++++++++++++++++++++++------------------ > 1 files changed, 50 insertions(+), 24 deletions(-) > > diff --git a/fs/sysv/super.c b/fs/sysv/super.c > index ac7b008..0433f23 100644 > --- a/fs/sysv/super.c > +++ b/fs/sysv/super.c > @@ -435,12 +436,46 @@ Ebadsize: > goto failed; > } > > -static int v7_fill_super(struct super_block *sb, void *data, int silent) > +static int v7_sanity_check(struct super_block *sb, struct buffer_head *bh) > { > - struct sysv_sb_info *sbi; > - struct buffer_head *bh, *bh2 = NULL; > struct v7_super_block *v7sb; > struct sysv_inode *v7i; > + struct buffer_head *bh2; > + struct sysv_sb_info *sbi; > + > + sbi = sb->s_fs_info; > + > + /* plausibility check on superblock */ > + v7sb = (struct v7_super_block *) bh->b_data; > + if (fs16_to_cpu(sbi, v7sb->s_nfree) > V7_NICFREE || > + fs16_to_cpu(sbi, v7sb->s_ninode) > V7_NICINOD || > + fs32_to_cpu(sbi, v7sb->s_fsize) > V7_MAXSIZE) > + return 0; > + > + /* plausibility check on root inode: it is a directory, > + with a nonzero size that is a multiple of 16 */ > + if ((bh2 = sb_bread(sb, 2)) == NULL) { > + return 0; > + } Don't need the braces. > + > + v7i = (struct sysv_inode *)(bh2->b_data + 64); > + if ((fs16_to_cpu(sbi, v7i->i_mode) & ~0777) != S_IFDIR || > + (fs32_to_cpu(sbi, v7i->i_size) == 0) || > + (fs32_to_cpu(sbi, v7i->i_size) & 017) || > + (fs32_to_cpu(sbi, v7i->i_size) > V7_NFILES * > + sizeof (struct sysv_dir_entry))) { sizeof(struct sysv_dir_entry))) { > + brelse(bh2); > + return 0; > + } > + > + brelse(bh2); > + return 1; > +} > + > +static int v7_fill_super(struct super_block *sb, void *data, int silent) > +{ > + struct sysv_sb_info *sbi; > + struct buffer_head *bh; > > if (440 != sizeof (struct v7_super_block)) > panic("V7 FS: bad super-block size"); > @@ -454,7 +489,6 @@ static int v7_fill_super(struct super_block *sb, void *data, int silent) > sbi->s_sb = sb; > sbi->s_block_base = 0; > sbi->s_type = FSTYPE_V7; > - sbi->s_bytesex = BYTESEX_PDP; > sb->s_fs_info = sbi; > > sb_set_blocksize(sb, 512); > @@ -466,34 +500,26 @@ static int v7_fill_super(struct super_block *sb, void *data, int silent) > goto failed; > } > > - /* plausibility check on superblock */ > - v7sb = (struct v7_super_block *) bh->b_data; > - if (fs16_to_cpu(sbi, v7sb->s_nfree) > V7_NICFREE || > - fs16_to_cpu(sbi, v7sb->s_ninode) > V7_NICINOD || > - fs32_to_cpu(sbi, v7sb->s_fsize) > V7_MAXSIZE) > - goto failed; > + /* Try PDP-11 UNIX */ > + sbi->s_bytesex = BYTESEX_PDP; > + if (v7_sanity_check (sb, bh)) > + goto detected; > > - /* plausibility check on root inode: it is a directory, > - with a nonzero size that is a multiple of 16 */ > - if ((bh2 = sb_bread(sb, 2)) == NULL) > - goto failed; > - v7i = (struct sysv_inode *)(bh2->b_data + 64); > - if ((fs16_to_cpu(sbi, v7i->i_mode) & ~0777) != S_IFDIR || > - (fs32_to_cpu(sbi, v7i->i_size) == 0) || > - (fs32_to_cpu(sbi, v7i->i_size) & 017) || > - (fs32_to_cpu(sbi, v7i->i_size) > V7_NFILES * > - sizeof (struct sysv_dir_entry))) > - goto failed; > - brelse(bh2); > - bh2 = NULL; > + /* Try PC/IX, v7/x86 */ > + sbi->s_bytesex = BYTESEX_LE; > + if (v7_sanity_check (sb, bh)) > + goto detected; > > + goto failed; > + > +detected: > sbi->s_bh1 = bh; > sbi->s_bh2 = bh; > if (complete_read_super(sb, silent, 1)) > return 0; > > failed: > - brelse(bh2); > + printk("VFS: could not find a valid V7 on %s.\n", sb->s_id); V7 fs (or V7 filesystem) > brelse(bh); > kfree(sbi); > return -EINVAL; > -- --- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** -- 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/