[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, 9 insertions, 7 deletions

diff --git a/fs/minix/itree_common.c b/fs/minix/itree_common.c
index 429baf8de105..a731cabf1540 100644
--- a/fs/minix/itree_common.c
+++ b/fs/minix/itree_common.c
@@ -23,7 +23,7 @@ static inline int verify_chain(Indirect *from, Indirect *to)
 
 static inline block_t *block_end(struct buffer_head *bh)
 {
-        return (block_t *)((char*)bh->b_data + BLOCK_SIZE);
+        return (block_t *)((char*)bh->b_data + bh->b_size);
 }
 
 static inline Indirect *get_branch(struct inode *inode,
@@ -85,7 +85,7 @@ static int alloc_branch(struct inode *inode,
                 branch[n].key = cpu_to_block(nr);
                 bh = sb_getblk(inode->i_sb, parent);
                 lock_buffer(bh);
-                memset(bh->b_data, 0, BLOCK_SIZE);
+                memset(bh->b_data, 0, bh->b_size);
                 branch[n].bh = bh;
                 branch[n].p = (block_t*) bh->b_data + offsets[n];
                 *branch[n].p = branch[n].key;
@@ -292,6 +292,7 @@ static void free_branches(struct inode *inode, block_t *p, block_t *q, int depth
 
 static inline void truncate (struct inode * inode)
 {
+        struct super_block *sb = inode->i_sb;
         block_t *idata = i_data(inode);
         int offsets[DEPTH];
         Indirect chain[DEPTH];
@@ -301,7 +302,7 @@ static inline void truncate (struct inode * inode)
         int first_whole;
         long iblock;
 
-        iblock = (inode->i_size + BLOCK_SIZE-1) >> 10;
+        iblock = (inode->i_size + sb->s_blocksize -1) >> sb->s_blocksize_bits;
         block_truncate_page(inode->i_mapping, inode->i_size, get_block);
 
         n = block_to_path(inode, iblock, offsets);
@@ -346,15 +347,16 @@ do_indirects:
         mark_inode_dirty(inode);
 }
 
-static inline unsigned nblocks(loff_t size)
+static inline unsigned nblocks(loff_t size, struct super_block *sb)
 {
+        int k = sb->s_blocksize_bits - 10;
         unsigned blocks, res, direct = DIRECT, i = DEPTH;
-        blocks = (size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS;
+        blocks = (size + sb->s_blocksize - 1) >> (BLOCK_SIZE_BITS + k);
         res = blocks;
         while (--i && blocks > direct) {
                 blocks -= direct;
-                blocks += BLOCK_SIZE/sizeof(block_t) - 1;
-                blocks /= BLOCK_SIZE/sizeof(block_t);
+                blocks += sb->s_blocksize/sizeof(block_t) - 1;
+                blocks /= sb->s_blocksize/sizeof(block_t);
                 res += blocks;
                 direct = 1;
         }