ufs_trunc_branch(): kill recursion

turn recursion into a pair of loops

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 26 insertions, 26 deletions

diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index dac81c318da7..314caad56d83 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -1124,34 +1124,14 @@ static void free_full_branch(struct inode *inode, int depth, void *p)
         mark_inode_dirty(inode);
 }
 
-static void ufs_trunc_branch(struct inode *inode, unsigned *offsets, int depth2, int depth, void *p)
+static void free_branch_tail(struct inode *inode, unsigned from, struct ufs_buffer_head *ubh, int depth)
 {
         struct super_block *sb = inode->i_sb;
         struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
-        struct ufs_inode_info *ufsi = UFS_I(inode);
-        struct ufs_buffer_head *ubh;
-        u64 tmp;
-        unsigned from = *offsets++;
         unsigned i;
 
-        tmp = ufs_data_ptr_to_cpu(sb, p);
-        if (!tmp)
-                return;
-        ubh = ubh_bread (sb, tmp, uspi->s_bsize);
-        if (!ubh) {
-                write_seqlock(&ufsi->meta_lock);
-                ufs_data_ptr_clear(uspi, p);
-                write_sequnlock(&ufsi->meta_lock);
-                return;
-        }
-
-        if (--depth2) {
-                void *ind = ubh_get_data_ptr(uspi, ubh, from++);
-                ufs_trunc_branch(inode, offsets, depth2, depth - 1, ind);
-                ubh_mark_buffer_dirty(ubh);
-        }
         if (--depth) {
-                for (i = from ; i < uspi->s_apb ; i++) {
+                for (i = from; i < uspi->s_apb ; i++) {
                         void *ind = ubh_get_data_ptr(uspi, ubh, i);
                         free_full_branch(inode, depth, ind);
                         ubh_mark_buffer_dirty(ubh);
@@ -1161,7 +1141,7 @@ static void ufs_trunc_branch(struct inode *inode, unsigned *offsets, int depth2,
 
                 for (i = from; i < uspi->s_apb; i++) {
                         void *ind = ubh_get_data_ptr(uspi, ubh, i);
-                        tmp = ufs_data_ptr_to_cpu(sb, ind);
+                        u64 tmp = ufs_data_ptr_to_cpu(sb, ind);
                         if (!tmp)
                                 continue;
 
@@ -1258,6 +1238,9 @@ static void __ufs_truncate_blocks(struct inode *inode)
         int depth = ufs_block_to_path(inode, DIRECT_BLOCK, offsets);
         int depth2;
         unsigned i;
+        struct ufs_buffer_head *ubh[3];
+        void *p;
+        u64 block;
 
         if (!depth)
                 return;
@@ -1272,9 +1255,26 @@ static void __ufs_truncate_blocks(struct inode *inode)
                 ufs_trunc_direct(inode);
                 offsets[0] = UFS_IND_BLOCK;
         } else {
-                if (depth2)
-                        ufs_trunc_branch(inode, offsets + 1, depth2, depth - 1,
-                           ufs_get_direct_data_ptr(uspi, ufsi, offsets[0]++));
+                /* get the blocks that should be partially emptied */
+                p = ufs_get_direct_data_ptr(uspi, ufsi, offsets[0]);
+                for (i = 0; i < depth2; i++) {
+                        offsets[i]++;   /* next branch is fully freed */
+                        block = ufs_data_ptr_to_cpu(sb, p);
+                        if (!block)
+                                break;
+                        ubh[i] = ubh_bread(sb, block, uspi->s_bsize);
+                        if (!ubh[i]) {
+                                write_seqlock(&ufsi->meta_lock);
+                                ufs_data_ptr_clear(uspi, p);
+                                write_sequnlock(&ufsi->meta_lock);
+                                break;
+                        }
+                        p = ubh_get_data_ptr(uspi, ubh[i], offsets[i + 1]);
+                }
+                while (i--) {
+                        ubh_mark_buffer_dirty(ubh[i]);
+                        free_branch_tail(inode, offsets[i + 1], ubh[i], depth - i - 1);
+                }
         }
         for (i = offsets[0]; i <= UFS_TIND_BLOCK; i++) {
                 free_full_branch(inode, i - UFS_IND_BLOCK + 1,