Messages in this thread Patch in this message | | | Date | Sun, 25 Jul 2010 17:26:18 -0700 | From | Randy Dunlap <> | Subject | Re: [PATCH] V7: Add support for non-PDP11 v7 filesystems |
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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 <hch@lst.de> > Cc: Al Viro <viro@ZenIV.linux.org.uk> > Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> > --- > 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 ***
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