libext2fs: move ext2fs_bmap2()'s the extent handling to a separate function

Separate the extent handling to a separate function to make BMAP_ALLOC
processing more efficient.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/lib/ext2fs/bmap.c b/lib/ext2fs/bmap.c
index 90d9e72d46b698e55438e6616bfdb832031ce449..f3e41c26f0333b0038e2a85de1713b4fd49d3150 100644 (file)
--- a/lib/ext2fs/bmap.c
+++ b/lib/ext2fs/bmap.c
@@ -129,13 +129,70 @@ static _BMAP_INLINE_ errcode_t block_tind_bmap(ext2_filsys fs, int flags,
        return retval;
 }
 
+static errcode_t extent_bmap(ext2_filsys fs, ext2_ino_t ino,
+                            struct ext2_inode *inode,
+                            ext2_extent_handle_t handle,
+                            char *block_buf, int bmap_flags, blk64_t block,
+                            int *ret_flags, int *blocks_alloc,
+                            blk64_t *phys_blk)
+{
+       struct ext2fs_extent    extent;
+       unsigned int            offset;
+       errcode_t               retval = 0;
+       blk64_t                 blk64;
+
+       if (bmap_flags & BMAP_SET) {
+               retval = ext2fs_extent_set_bmap(handle, block,
+                                               *phys_blk, 0);
+               return retval;
+       }
+       retval = ext2fs_extent_goto(handle, block);
+       if (retval) {
+               /* If the extent is not found, return phys_blk = 0 */
+               if (retval == EXT2_ET_EXTENT_NOT_FOUND)
+                       goto got_block;
+               return retval;
+       }
+       retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
+       if (retval)
+               return retval;
+       offset = block - extent.e_lblk;
+       if (block >= extent.e_lblk && (offset <= extent.e_len)) {
+               *phys_blk = extent.e_pblk + offset;
+               if (ret_flags && extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+                       *ret_flags |= BMAP_RET_UNINIT;
+       }
+got_block:
+       if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
+               retval = extent_bmap(fs, ino, inode, handle, block_buf,
+                                    0, block-1, 0, blocks_alloc, &blk64);
+               if (retval)
+                       blk64 = 0;
+               retval = ext2fs_alloc_block2(fs, blk64, block_buf,
+                                            &blk64);
+               if (retval)
+                       return retval;
+               retval = ext2fs_extent_set_bmap(handle, block,
+                                               blk64, 0);
+               if (retval)
+                       return retval;
+               /* Update inode after setting extent */
+               retval = ext2fs_read_inode(fs, ino, inode);
+               if (retval)
+                       return retval;
+               *blocks_alloc += 1;
+               *phys_blk = blk64;
+       }
+       return 0;
+}
+
+
 errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
                       char *block_buf, int bmap_flags, blk64_t block,
                       int *ret_flags, blk64_t *phys_blk)
 {
        struct ext2_inode inode_buf;
        ext2_extent_handle_t handle = 0;
-       blk64_t blk64;
        blk_t addr_per_block;
        blk_t   b, blk32;
        char    *buf = 0;
@@ -157,59 +214,6 @@ errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
        }
        addr_per_block = (blk_t) fs->blocksize >> 2;
 
-       if (inode->i_flags & EXT4_EXTENTS_FL) {
-               struct ext2fs_extent    extent;
-               unsigned int            offset;
-
-               retval = ext2fs_extent_open2(fs, ino, inode, &handle);
-               if (retval)
-                       goto done;
-               if (bmap_flags & BMAP_SET) {
-                       retval = ext2fs_extent_set_bmap(handle, block,
-                                                       *phys_blk, 0);
-                       goto done;
-               }
-               retval = ext2fs_extent_goto(handle, block);
-               if (retval) {
-                       /* If the extent is not found, return phys_blk = 0 */
-                       if (retval == EXT2_ET_EXTENT_NOT_FOUND)
-                               goto got_block;
-                       goto done;
-               }
-               retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
-               if (retval)
-                       goto done;
-               offset = block - extent.e_lblk;
-               if (block >= extent.e_lblk && (offset <= extent.e_len)) {
-                       *phys_blk = extent.e_pblk + offset;
-                       if (ret_flags && extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
-                               *ret_flags |= BMAP_RET_UNINIT;
-               }
-       got_block:
-               if ((*phys_blk == 0) && (bmap_flags & BMAP_ALLOC)) {
-                       retval = ext2fs_bmap2(fs, ino, inode, block_buf,
-                                             0, block-1, 0, &blk64);
-                       if (retval)
-                               blk64 = 0;
-                       retval = ext2fs_alloc_block2(fs, blk64, block_buf,
-                                                    &blk64);
-                       if (retval)
-                               goto done;
-                       retval = ext2fs_extent_set_bmap(handle, block,
-                                                       blk64, 0);
-                       if (retval)
-                               goto done;
-                       /* Update inode after setting extent */
-                       retval = ext2fs_read_inode(fs, ino, inode);
-                       if (retval)
-                               return retval;
-                       blocks_alloc++;
-                       *phys_blk = blk64;
-               }
-               retval = 0;
-               goto done;
-       }
-
        if (!block_buf) {
                retval = ext2fs_get_array(2, fs->blocksize, &buf);
                if (retval)
@@ -217,6 +221,16 @@ errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
                block_buf = buf;
        }
 
+       if (inode->i_flags & EXT4_EXTENTS_FL) {
+               retval = ext2fs_extent_open2(fs, ino, inode, &handle);
+               if (retval)
+                       goto done;
+               retval = extent_bmap(fs, ino, inode, handle, block_buf,
+                                    bmap_flags, block, ret_flags,
+                                    &blocks_alloc, phys_blk);
+               goto done;
+       }
+
        if (block < EXT2_NDIR_BLOCKS) {
                if (bmap_flags & BMAP_SET) {
                        b = *phys_blk;