[PATCH] Minix V3 support

This morning I needed to read a Minix V3 filesystem, but unfortunately my
2.6.19 did not support that, and neither did the downloaded 2.6.20rc4.

Fortunately, google told me that Daniel Aragones had already done the work,
patch found at http://www.terra.es/personal2/danarag/

Unfortunaly, looking at the patch was painful to my eyes, so I polished it
a bit before applying.  The resulting kernel boots, and reads the
filesystem it needed to read.

Signed-off-by: Daniel Aragones <danarag@gmail.com>
Signed-off-by: Andries Brouwer <aeb@cwi.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 38 insertions, 11 deletions

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 629e09b38c5c..9ddfcc148287 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -7,6 +7,7 @@
  *      Minix V2 fs support.
  *
  *  Modified for 680x0 by Andreas Schwab
+ *  Updated to filesystem version 3 by Daniel Aragones
  */
 
 #include <linux/module.h>
@@ -36,7 +37,8 @@ static void minix_put_super(struct super_block *sb)
         struct minix_sb_info *sbi = minix_sb(sb);
 
         if (!(sb->s_flags & MS_RDONLY)) {
-                sbi->s_ms->s_state = sbi->s_mount_state;
+                if (sbi->s_version != MINIX_V3)  /* s_state is now out from V3 sb */
+                        sbi->s_ms->s_state = sbi->s_mount_state;
                 mark_buffer_dirty(sbi->s_sbh);
         }
         for (i = 0; i < sbi->s_imap_blocks; i++)
@@ -117,12 +119,17 @@ static int minix_remount (struct super_block * sb, int * flags, char * data)
                     !(sbi->s_mount_state & MINIX_VALID_FS))
                         return 0;
                 /* Mounting a rw partition read-only. */
-                ms->s_state = sbi->s_mount_state;
+                if (sbi->s_version != MINIX_V3)
+                        ms->s_state = sbi->s_mount_state;
                 mark_buffer_dirty(sbi->s_sbh);
         } else {
                 /* Mount a partition which is read-only, read-write. */
-                sbi->s_mount_state = ms->s_state;
-                ms->s_state &= ~MINIX_VALID_FS;
+                if (sbi->s_version != MINIX_V3) {
+                        sbi->s_mount_state = ms->s_state;
+                        ms->s_state &= ~MINIX_VALID_FS;
+                } else {
+                        sbi->s_mount_state = MINIX_VALID_FS;
+                }
                 mark_buffer_dirty(sbi->s_sbh);
 
                 if (!(sbi->s_mount_state & MINIX_VALID_FS))
@@ -140,7 +147,8 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
         struct buffer_head *bh;
         struct buffer_head **map;
         struct minix_super_block *ms;
-        int i, block;
+        struct minix3_super_block *m3s = NULL;
+        unsigned long i, block;
         struct inode *root_inode;
         struct minix_sb_info *sbi;
 
@@ -192,6 +200,22 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
                 sbi->s_dirsize = 32;
                 sbi->s_namelen = 30;
                 sbi->s_link_max = MINIX2_LINK_MAX;
+        } else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
+                m3s = (struct minix3_super_block *) bh->b_data;
+                s->s_magic = m3s->s_magic;
+                sbi->s_imap_blocks = m3s->s_imap_blocks;
+                sbi->s_zmap_blocks = m3s->s_zmap_blocks;
+                sbi->s_firstdatazone = m3s->s_firstdatazone;
+                sbi->s_log_zone_size = m3s->s_log_zone_size;
+                sbi->s_max_size = m3s->s_max_size;
+                sbi->s_ninodes = m3s->s_ninodes;
+                sbi->s_nzones = m3s->s_zones;
+                sbi->s_dirsize = 64;
+                sbi->s_namelen = 60;
+                sbi->s_version = MINIX_V3;
+                sbi->s_link_max = MINIX2_LINK_MAX;
+                sbi->s_mount_state = MINIX_VALID_FS;
+                sb_set_blocksize(s, m3s->s_blocksize);
         } else
                 goto out_no_fs;
 
@@ -236,7 +260,8 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
                 s->s_root->d_op = &minix_dentry_operations;
 
         if (!(s->s_flags & MS_RDONLY)) {
-                ms->s_state &= ~MINIX_VALID_FS;
+                if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
+                        ms->s_state &= ~MINIX_VALID_FS;
                 mark_buffer_dirty(bh);
         }
         if (!(sbi->s_mount_state & MINIX_VALID_FS))
@@ -278,8 +303,8 @@ out_illegal_sb:
 
 out_no_fs:
         if (!silent)
-                printk("VFS: Can't find a Minix or Minix V2 filesystem "
-                        "on device %s\n", s->s_id);
+                printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
+                       "on device %s.\n", s->s_id);
 out_release:
         brelse(bh);
         goto out;
@@ -537,12 +562,14 @@ int minix_sync_inode(struct inode * inode)
 
 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 {
+        struct inode *dir = dentry->d_parent->d_inode;
+        struct super_block *sb = dir->i_sb;
         generic_fillattr(dentry->d_inode, stat);
         if (INODE_VERSION(dentry->d_inode) == MINIX_V1)
-                stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size);
+                stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
         else
-                stat->blocks = (BLOCK_SIZE / 512) * V2_minix_blocks(stat->size);
-        stat->blksize = BLOCK_SIZE;
+                stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
+        stat->blksize = sb->s_blocksize;
         return 0;
 }