GFS2: split function rgblk_search

This patch splits function rgblk_search into a function that finds
blocks to allocate (rgblk_search) and a function that assigns those
blocks (gfs2_alloc_extent).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@rehat.com>

1 files changed, 51 insertions, 25 deletions

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index f1d19603d237..6b6cc096756a 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -65,8 +65,8 @@ static const char valid_change[16] = {
 };
 
 static u32 rgblk_search(struct gfs2_rgrpd *rgd, u32 goal,
-                        unsigned char old_state, bool dinode,
-                        unsigned int *ndata);
+                        unsigned char old_state, bool dinode,
+                        struct gfs2_bitmap **rbi);
 
 /**
  * gfs2_setbit - Set a bit in the bitmaps
@@ -899,6 +899,11 @@ static int try_rgrp_fit(const struct gfs2_rgrpd *rgd, const struct gfs2_inode *i
         return 0;
 }
 
+static inline u32 gfs2_bi2rgd_blk(struct gfs2_bitmap *bi, u32 blk)
+{
+        return (bi->bi_start * GFS2_NBBY) + blk;
+}
+
 /**
  * try_rgrp_unlink - Look for any unlinked, allocated, but unused inodes
  * @rgd: The rgrp
@@ -912,19 +917,20 @@ static void try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, u64 skip
         u32 goal = 0, block;
         u64 no_addr;
         struct gfs2_sbd *sdp = rgd->rd_sbd;
-        unsigned int n;
         struct gfs2_glock *gl;
         struct gfs2_inode *ip;
         int error;
         int found = 0;
+        struct gfs2_bitmap *bi;
 
         while (goal < rgd->rd_data) {
                 down_write(&sdp->sd_log_flush_lock);
-                n = 1;
-                block = rgblk_search(rgd, goal, GFS2_BLKST_UNLINKED, 0, &n);
+                block = rgblk_search(rgd, goal, GFS2_BLKST_UNLINKED, 0, &bi);
                 up_write(&sdp->sd_log_flush_lock);
                 if (block == BFITNOENT)
                         break;
+
+                block = gfs2_bi2rgd_blk(bi, block);
                 /* rgblk_search can return a block < goal, so we need to
                    keep it marching forward. */
                 no_addr = block + rgd->rd_data0;
@@ -1109,38 +1115,35 @@ static unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, u64 block)
 }
 
 /**
- * rgblk_search - find a block in @old_state, change allocation
- *           state to @new_state
+ * rgblk_search - find a block in @old_state
  * @rgd: the resource group descriptor
  * @goal: the goal block within the RG (start here to search for avail block)
  * @old_state: GFS2_BLKST_XXX the before-allocation state to find
  * @dinode: TRUE if the first block we allocate is for a dinode
- * @n: The extent length
+ * @rbi: address of the pointer to the bitmap containing the block found
  *
  * Walk rgrp's bitmap to find bits that represent a block in @old_state.
- * Add the found bitmap buffer to the transaction.
- * Set the found bits to @new_state to change block's allocation state.
  *
  * This function never fails, because we wouldn't call it unless we
  * know (from reservation results, etc.) that a block is available.
  *
- * Scope of @goal and returned block is just within rgrp, not the whole
- * filesystem.
+ * Scope of @goal is just within rgrp, not the whole filesystem.
+ * Scope of @returned block is just within bitmap, not the whole filesystem.
  *
- * Returns:  the block number allocated
+ * Returns: the block number found relative to the bitmap rbi
  */
 
 static u32 rgblk_search(struct gfs2_rgrpd *rgd, u32 goal,
-                        unsigned char old_state, bool dinode, unsigned int *n)
+                        unsigned char old_state, bool dinode,
+                        struct gfs2_bitmap **rbi)
 {
         struct gfs2_bitmap *bi = NULL;
         const u32 length = rgd->rd_length;
         u32 blk = BFITNOENT;
         unsigned int buf, x;
-        const unsigned int elen = *n;
         const u8 *buffer = NULL;
 
-        *n = 0;
+        *rbi = NULL;
         /* Find bitmap block that contains bits for goal block */
         for (buf = 0; buf < length; buf++) {
                 bi = rgd->rd_bits + buf;
@@ -1187,12 +1190,32 @@ skip:
                 goal = 0;
         }
 
-        if (blk == BFITNOENT)
-                return blk;
+        if (blk != BFITNOENT)
+                *rbi = bi;
 
-        if (old_state == GFS2_BLKST_UNLINKED)
-                goto out;
+        return blk;
+}
 
+/**
+ * gfs2_alloc_extent - allocate an extent from a given bitmap
+ * @rgd: the resource group descriptor
+ * @bi: the bitmap within the rgrp
+ * @blk: the block within the bitmap
+ * @dinode: TRUE if the first block we allocate is for a dinode
+ * @n: The extent length
+ *
+ * Add the found bitmap buffer to the transaction.
+ * Set the found bits to @new_state to change block's allocation state.
+ * Returns: starting block number of the extent (fs scope)
+ */
+static u64 gfs2_alloc_extent(struct gfs2_rgrpd *rgd, struct gfs2_bitmap *bi,
+                             u32 blk, bool dinode, unsigned int *n)
+{
+        const unsigned int elen = *n;
+        u32 goal;
+        const u8 *buffer = NULL;
+
+        buffer = bi->bi_bh->b_data + bi->bi_offset;
         gfs2_trans_add_bh(rgd->rd_gl, bi->bi_bh, 1);
         gfs2_setbit(rgd, bi->bi_bh->b_data, bi->bi_clone, bi->bi_offset,
                     bi, blk, dinode ? GFS2_BLKST_DINODE : GFS2_BLKST_USED);
@@ -1210,8 +1233,9 @@ skip:
                             bi, goal, GFS2_BLKST_USED);
                 (*n)++;
         }
-out:
-        return (bi->bi_start * GFS2_NBBY) + blk;
+        blk = gfs2_bi2rgd_blk(bi, blk);
+        rgd->rd_last_alloc = blk;
+        return rgd->rd_data0 + blk;
 }
 
 /**
@@ -1319,6 +1343,7 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *ndata,
         u32 goal, extlen, blk; /* block, within the rgrp scope */
         u64 block; /* block, within the file system scope */
         int error;
+        struct gfs2_bitmap *bi;
 
         /* Only happens if there is a bug in gfs2, return something distinctive
          * to ensure that it is noticed.
@@ -1333,14 +1358,15 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *ndata,
         else
                 goal = rgd->rd_last_alloc;
 
-        blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, dinode, ndata);
+        blk = rgblk_search(rgd, goal, GFS2_BLKST_FREE, dinode, &bi);
 
+        *ndata = 0;
         /* Since all blocks are reserved in advance, this shouldn't happen */
         if (blk == BFITNOENT)
                 goto rgrp_error;
 
-        rgd->rd_last_alloc = blk;
-        block = rgd->rd_data0 + blk;
+        block = gfs2_alloc_extent(rgd, bi, blk, dinode, ndata);
+
         if (!dinode) {
                 ip->i_goal = block + *ndata - 1;
                 error = gfs2_meta_inode_buffer(ip, &dibh);