[GFS2] Tidy up bmap & fix boundary bug

This moves the locking for bmap into the bmap function itself
rather than using a wrapper function. It also fixes a bug where
the boundary flag was set on the wrong bh. Also the flags on
the mapped bh are reset earlier in the function to ensure that
they are 100% correct on the error path.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 54 insertions, 63 deletions

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 06e3447ea132..8240c1ff94f4 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -423,12 +423,29 @@ static int lookup_block(struct gfs2_inode *ip, struct buffer_head *bh,
         return 0;
 }
 
+static inline void bmap_lock(struct inode *inode, int create)
+{
+        struct gfs2_inode *ip = GFS2_I(inode);
+        if (create)
+                down_write(&ip->i_rw_mutex);
+        else
+                down_read(&ip->i_rw_mutex);
+}
+
+static inline void bmap_unlock(struct inode *inode, int create)
+{
+        struct gfs2_inode *ip = GFS2_I(inode);
+        if (create)
+                up_write(&ip->i_rw_mutex);
+        else
+                up_read(&ip->i_rw_mutex);
+}
+
 /**
- * gfs2_block_pointers - Map a block from an inode to a disk block
+ * gfs2_block_map - Map a block from an inode to a disk block
  * @inode: The inode
  * @lblock: The logical block number
- * @map_bh: The bh to be mapped
- * @mp: metapath to use
+ * @bh_map: The bh to be mapped
  *
  * Find the block number on the current device which corresponds to an
  * inode's block. If the block had to be created, "new" will be set.
@@ -436,8 +453,8 @@ static int lookup_block(struct gfs2_inode *ip, struct buffer_head *bh,
  * Returns: errno
  */
 
-static int gfs2_block_pointers(struct inode *inode, u64 lblock, int create,
-                               struct buffer_head *bh_map, struct metapath *mp)
+int gfs2_block_map(struct inode *inode, u64 lblock, int create,
+                   struct buffer_head *bh_map)
 {
         struct gfs2_inode *ip = GFS2_I(inode);
         struct gfs2_sbd *sdp = GFS2_SB(inode);
@@ -451,51 +468,55 @@ static int gfs2_block_pointers(struct inode *inode, u64 lblock, int create,
         u64 dblock = 0;
         int boundary;
         unsigned int maxlen = bh_map->b_size >> inode->i_blkbits;
+        struct metapath mp;
+        u64 size;
 
         BUG_ON(maxlen == 0);
 
         if (gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
                 return 0;
 
+        bmap_lock(inode, create);
+        clear_buffer_mapped(bh_map);
+        clear_buffer_new(bh_map);
+        clear_buffer_boundary(bh_map);
         bsize = gfs2_is_dir(ip) ? sdp->sd_jbsize : sdp->sd_sb.sb_bsize;
-
-        height = calc_tree_height(ip, (lblock + 1) * bsize);
-        if (ip->i_di.di_height < height) {
-                if (!create)
-                        return 0;
-
-                error = build_height(inode, height);
-                if (error)
-                        return error;
+        size = (lblock + 1) * bsize;
+
+        if (size > ip->i_di.di_size) {
+                height = calc_tree_height(ip, size);
+                if (ip->i_di.di_height < height) {
+                        if (!create)
+                                goto out_ok;
+        
+                        error = build_height(inode, height);
+                        if (error)
+                                goto out_fail;
+                }
         }
 
-        find_metapath(ip, lblock, mp);
+        find_metapath(ip, lblock, &mp);
         end_of_metadata = ip->i_di.di_height - 1;
-
         error = gfs2_meta_inode_buffer(ip, &bh);
         if (error)
-                return error;
+                goto out_fail;
 
         for (x = 0; x < end_of_metadata; x++) {
-                lookup_block(ip, bh, x, mp, create, &new, &dblock);
+                lookup_block(ip, bh, x, &mp, create, &new, &dblock);
                 brelse(bh);
                 if (!dblock)
-                        return 0;
+                        goto out_ok;
 
                 error = gfs2_meta_indirect_buffer(ip, x+1, dblock, new, &bh);
                 if (error)
-                        return error;
+                        goto out_fail;
         }
 
-        boundary = lookup_block(ip, bh, end_of_metadata, mp, create, &new, &dblock);
-        clear_buffer_mapped(bh_map);
-        clear_buffer_new(bh_map);
-        clear_buffer_boundary(bh_map);
-
+        boundary = lookup_block(ip, bh, end_of_metadata, &mp, create, &new, &dblock);
         if (dblock) {
                 map_bh(bh_map, inode->i_sb, dblock);
                 if (boundary)
-                        set_buffer_boundary(bh);
+                        set_buffer_boundary(bh_map);
                 if (new) {
                         struct buffer_head *dibh;
                         error = gfs2_meta_inode_buffer(ip, &dibh);
@@ -510,8 +531,8 @@ static int gfs2_block_pointers(struct inode *inode, u64 lblock, int create,
                 while(--maxlen && !buffer_boundary(bh_map)) {
                         u64 eblock;
 
-                        mp->mp_list[end_of_metadata]++;
-                        boundary = lookup_block(ip, bh, end_of_metadata, mp, 0, &new, &eblock);
+                        mp.mp_list[end_of_metadata]++;
+                        boundary = lookup_block(ip, bh, end_of_metadata, &mp, 0, &new, &eblock);
                         if (eblock != ++dblock)
                                 break;
                         bh_map->b_size += (1 << inode->i_blkbits);
@@ -521,43 +542,15 @@ static int gfs2_block_pointers(struct inode *inode, u64 lblock, int create,
         }
 out_brelse:
         brelse(bh);
-        return 0;
-}
-
-
-static inline void bmap_lock(struct inode *inode, int create)
-{
-        struct gfs2_inode *ip = GFS2_I(inode);
-        if (create)
-                down_write(&ip->i_rw_mutex);
-        else
-                down_read(&ip->i_rw_mutex);
-}
-
-static inline void bmap_unlock(struct inode *inode, int create)
-{
-        struct gfs2_inode *ip = GFS2_I(inode);
-        if (create)
-                up_write(&ip->i_rw_mutex);
-        else
-                up_read(&ip->i_rw_mutex);
-}
-
-int gfs2_block_map(struct inode *inode, u64 lblock, int create,
-                   struct buffer_head *bh)
-{
-        struct metapath mp;
-        int ret;
-
-        bmap_lock(inode, create);
-        ret = gfs2_block_pointers(inode, lblock, create, bh, &mp);
+out_ok:
+        error = 0;
+out_fail:
         bmap_unlock(inode, create);
-        return ret;
+        return error;
 }
 
 int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen)
 {
-        struct metapath mp;
         struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 };
         int ret;
         int create = *new;
@@ -567,9 +560,7 @@ int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsi
         BUG_ON(!new);
 
         bh.b_size = 1 << (inode->i_blkbits + 5);
-        bmap_lock(inode, create);
-        ret = gfs2_block_pointers(inode, lblock, create, &bh, &mp);
-        bmap_unlock(inode, create);
+        ret = gfs2_block_map(inode, lblock, create, &bh);
         *extlen = bh.b_size >> inode->i_blkbits;
         *dblock = bh.b_blocknr;
         if (buffer_new(&bh))