tune2fs: Fix inefficient O(n**2) algorithms when expanding the inode size

When running "tune2fs -I 256" on moderate to large filesystems, the
time required to run tune2fs can take many hours (20+ before some
users gave up in disgust).  This was due to some O(n**2) and O(n*m)
algorithms in move_block() and inode_scan_and_fix(), respectively.

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

diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index b29b344..e72518a 100644 (file)
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -1011,13 +1011,13 @@ static int move_block(ext2_filsys fs, ext2fs_block_bitmap bmap)
        if (retval)
                return retval;
 
-       for (blk = fs->super->s_first_data_block;
-                       blk < fs->super->s_blocks_count; blk++) {
+       for (new_blk = blk = fs->super->s_first_data_block;
+            blk < fs->super->s_blocks_count; blk++) {
 
                if (!ext2fs_test_block_bitmap(bmap, blk))
                        continue;
 
-               retval = ext2fs_new_block(fs, blk, NULL, &new_blk);
+               retval = ext2fs_new_block(fs, new_blk, NULL, &new_blk);
                if (retval)
                        goto err_out;
 
@@ -1068,12 +1068,14 @@ static int process_block(ext2_filsys fs EXT2FS_ATTR((unused)),
                         e2_blkcnt_t blockcnt EXT2FS_ATTR((unused)),
                         blk_t ref_block EXT2FS_ATTR((unused)),
                         int ref_offset EXT2FS_ATTR((unused)),
-                        void *priv_data EXT2FS_ATTR((unused)))
+                        void *priv_data)
 {
        int ret = 0;
        blk_t new_blk;
+       ext2fs_block_bitmap bmap = (ext2fs_block_bitmap) priv_data;
 
-
+       if (!ext2fs_test_block_bitmap(bmap, *block_nr))
+               return 0;
        new_blk = transalate_block(*block_nr);
        if (new_blk) {
                *block_nr = new_blk;
@@ -1086,7 +1088,7 @@ static int process_block(ext2_filsys fs EXT2FS_ATTR((unused)),
        return ret;
 }
 
-static int inode_scan_and_fix(ext2_filsys fs)
+static int inode_scan_and_fix(ext2_filsys fs, ext2fs_block_bitmap bmap)
 {
        errcode_t retval = 0;
        ext2_ino_t ino;
@@ -1122,8 +1124,8 @@ static int inode_scan_and_fix(ext2_filsys fs)
                 * Do we need to fix this ??
                 */
 
-               if (inode.i_file_acl) {
-
+               if (inode.i_file_acl &&
+                   ext2fs_test_block_bitmap(bmap, inode.i_file_acl)) {
                        blk = transalate_block(inode.i_file_acl);
                        if (!blk)
                                continue;
@@ -1142,9 +1144,8 @@ static int inode_scan_and_fix(ext2_filsys fs)
                if (!ext2fs_inode_has_valid_blocks(&inode))
                        continue;
 
-               retval = ext2fs_block_iterate2(fs, ino, 0,
-                                               block_buf, process_block,
-                                               0);
+               retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
+                                              process_block, bmap);
                if (retval)
                        goto err_out;
 
@@ -1344,7 +1345,7 @@ static int resize_inode(ext2_filsys fs, unsigned long new_size)
        if (retval)
                goto err_out;
 
-       retval = inode_scan_and_fix(fs);
+       retval = inode_scan_and_fix(fs, bmap);
        if (retval)
                goto err_out;