e2fsck: Fix directory with holes even when i_size is wrong

The old method for detecting directories with holes depended on i_size
being correct, even though the correct value of i_size hadn't been
calculated yet.  Hence, a directory inode with holes and an i_size of
0 would require two e2fsck passes to fix completely.

The replacement method for determining whether or not
ext2fs_add_dir_block() should be called is more reliable, and reduces
the size of e2fsck and makes the code more readable as a bonus.

Thanks to Mikulas Patocka for providing a sample file system which
demonstrated this problem.

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

diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index 2531e57..b534841 100644 (file)
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -83,6 +83,7 @@ struct process_block_struct {
        blk_t           num_blocks;
        blk_t           max_blocks;
        e2_blkcnt_t     last_block;
+       e2_blkcnt_t     last_db_block;
        int             num_illegal_blocks;
        blk_t           previous_block;
        struct ext2_inode *inode;
@@ -767,6 +768,7 @@ void e2fsck_pass1(e2fsck_t ctx)
                        }
                        pb.ino = EXT2_BAD_INO;
                        pb.num_blocks = pb.last_block = 0;
+                       pb.last_db_block = -1;
                        pb.num_illegal_blocks = 0;
                        pb.suppress = 0; pb.clear = 0; pb.is_dir = 0;
                        pb.is_reg = 0; pb.fragmented = 0; pb.bbcheck = 0;
@@ -1820,6 +1822,7 @@ static void check_blocks(e2fsck_t ctx, struct problem_context *pctx,
        pb.ino = ino;
        pb.num_blocks = 0;
        pb.last_block = -1;
+       pb.last_db_block = -1;
        pb.num_illegal_blocks = 0;
        pb.suppress = 0; pb.clear = 0;
        pb.fragmented = 0;
@@ -1883,26 +1886,6 @@ static void check_blocks(e2fsck_t ctx, struct problem_context *pctx,
                return;
        }
 
-       if (pb.is_dir) {
-               while (1) {
-                       struct ext2_db_entry *entry;
-
-                       if (ext2fs_dblist_get_last(fs->dblist, &entry) ||
-                           (entry->ino != ino) ||
-                           (entry->blk != 0) ||
-                           (entry->blockcnt == 0))
-                               break;
-                       /* printf("Dropping ino %lu blk %lu blockcnt %d\n",
-                                 entry->ino, entry->blk, entry->blockcnt); */
-                       ext2fs_dblist_drop_last(fs->dblist);
-                       if (ext2fs_dblist_get_last(fs->dblist, &entry) ||
-                           (entry->ino != ino))
-                               pb.last_block--;
-                       else
-                               pb.last_block = entry->blockcnt;
-               }
-       }
-
        if (inode->i_flags & EXT2_INDEX_FL) {
                if (handle_htree(ctx, pctx, ino, inode, block_buf)) {
                        inode->i_flags &= ~EXT2_INDEX_FL;
@@ -2094,31 +2077,8 @@ static int process_block(ext2_filsys fs,
                return 0;
        }
 
-       if (blk == 0) {
-               if (p->is_dir == 0) {
-                       /*
-                        * Should never happen, since only directories
-                        * get called with BLOCK_FLAG_HOLE
-                        */
-#if DEBUG_E2FSCK
-                       printf("process_block() called with blk == 0, "
-                              "blockcnt=%d, inode %lu???\n",
-                              blockcnt, p->ino);
-#endif
-                       return 0;
-               }
-               if (blockcnt < 0)
-                       return 0;
-               if (blockcnt * fs->blocksize < p->inode->i_size) {
-#if 0
-                       printf("Missing block (#%d) in directory inode %lu!\n",
-                              blockcnt, p->ino);
-#endif
-                       p->last_block = blockcnt;
-                       goto mark_dir;
-               }
+       if (blk == 0)
                return 0;
-       }
 
 #if 0
        printf("Process_block, inode %lu, block %u, #%d\n", p->ino, blk,
@@ -2203,11 +2163,22 @@ static int process_block(ext2_filsys fs,
                p->last_block = blockcnt;
 mark_dir:
        if (p->is_dir && (blockcnt >= 0)) {
+               while (++p->last_db_block < blockcnt) {
+                       pctx->errcode = ext2fs_add_dir_block(fs->dblist,
+                                                            p->ino, 0,
+                                                            p->last_db_block);
+                       if (pctx->errcode) {
+                               pctx->blk = 0;
+                               pctx->num = p->last_db_block;
+                               goto failed_add_dir_block;
+                       }
+               }
                pctx->errcode = ext2fs_add_dir_block(fs->dblist, p->ino,
                                                    blk, blockcnt);
                if (pctx->errcode) {
                        pctx->blk = blk;
                        pctx->num = blockcnt;
+               failed_add_dir_block:
                        fix_problem(ctx, PR_1_ADD_DBLOCK, pctx);
                        /* Should never get here */
                        ctx->flags |= E2F_FLAG_ABORT;