e2fsck: check and fix tails of all bitmap blocks

Currently, e2fsck effectively checks only tail of the last inode and
block bitmap in the filesystem. Thus if some previous bitmap has unset
bits it goes unnoticed.  Mostly these tail bits in the bitmap are
ignored; however, if blocks_per_group are smaller than 8*blocksize,
the multi-block allocator in the kernel can get confused when the tail
bits are unset and return bogus free extent.

Add support to libext2fs to check these bitmap tails when loading
bitmaps (as that's about the only place which has access to the bitmap
tail bits) and make e2fsck use this functionality to detect buggy bitmap
tails and fix them (by rewriting the bitmaps).

Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

diff --git a/e2fsck/pass5.c b/e2fsck/pass5.c
index 7803e8b..8100909 100644 (file)
--- a/e2fsck/pass5.c
+++ b/e2fsck/pass5.c
@@ -838,6 +838,7 @@ static void check_inode_end(e2fsck_t ctx)
        ext2_filsys fs = ctx->fs;
        ext2_ino_t      end, save_inodes_count, i;
        struct problem_context  pctx;
+       int asked = 0;
 
        clear_problem_context(&pctx);
 
@@ -851,11 +852,12 @@ static void check_inode_end(e2fsck_t ctx)
                return;
        }
        if (save_inodes_count == end)
-               return;
+               goto check_intra_bg_tail;
 
        /* protect loop from wrap-around if end is maxed */
        for (i = save_inodes_count + 1; i <= end && i > save_inodes_count; i++) {
                if (!ext2fs_test_inode_bitmap(fs->inode_map, i)) {
+                       asked = 1;
                        if (fix_problem(ctx, PR_5_INODE_BMAP_PADDING, &pctx)) {
                                for (; i <= end; i++)
                                        ext2fs_mark_inode_bitmap(fs->inode_map,
@@ -875,6 +877,20 @@ static void check_inode_end(e2fsck_t ctx)
                ctx->flags |= E2F_FLAG_ABORT; /* fatal */
                return;
        }
+       /*
+        * If the number of inodes per block group != blocksize, we
+        * can also have a potential problem with the tail bits in
+        * each individual inode bitmap block.  If there is a problem,
+        * it would have been noticed when the bitmap was loaded.  And
+        * fixing this is easy; all we need to do force the bitmap to
+        * be written back to disk.
+        */
+check_intra_bg_tail:
+       if (!asked && fs->flags & EXT2_FLAG_IBITMAP_TAIL_PROBLEM)
+               if (fix_problem(ctx, PR_5_INODE_BMAP_PADDING, &pctx))
+                       ext2fs_mark_ib_dirty(fs);
+               else
+                       ext2fs_unmark_valid(fs);
 }
 
 static void check_block_end(e2fsck_t ctx)
@@ -882,6 +898,7 @@ static void check_block_end(e2fsck_t ctx)
        ext2_filsys fs = ctx->fs;
        blk64_t end, save_blocks_count, i;
        struct problem_context  pctx;
+       int asked = 0;
 
        clear_problem_context(&pctx);
 
@@ -896,12 +913,13 @@ static void check_block_end(e2fsck_t ctx)
                return;
        }
        if (save_blocks_count == end)
-               return;
+               goto check_intra_bg_tail;
 
        /* Protect loop from wrap-around if end is maxed */
        for (i = save_blocks_count + 1; i <= end && i > save_blocks_count; i++) {
                if (!ext2fs_test_block_bitmap2(fs->block_map,
                                               EXT2FS_C2B(fs, i))) {
+                       asked = 1;
                        if (fix_problem(ctx, PR_5_BLOCK_BMAP_PADDING, &pctx)) {
                                for (; i <= end; i++)
                                        ext2fs_mark_block_bitmap2(fs->block_map,
@@ -921,7 +939,19 @@ static void check_block_end(e2fsck_t ctx)
                ctx->flags |= E2F_FLAG_ABORT; /* fatal */
                return;
        }
+       /*
+        * If the number of blocks per block group != blocksize, we
+        * can also have a potential problem with the tail bits in
+        * each individual block bitmap block.  If there is a problem,
+        * it would have been noticed when the bitmap was loaded.  And
+        * fixing this is easy; all we need to do force the bitmap to
+        * be written back to disk.
+        */
+check_intra_bg_tail:
+       if (!asked && fs->flags & EXT2_FLAG_BBITMAP_TAIL_PROBLEM) {
+               if (fix_problem(ctx, PR_5_BLOCK_BMAP_PADDING, &pctx))
+                       ext2fs_mark_bb_dirty(fs);
+               else
+                       ext2fs_unmark_valid(fs);
+       }
 }
-
-
-

diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 7d7c346..59fd974 100644 (file)
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -204,6 +204,8 @@ typedef struct ext2_file *ext2_file_t;
 #define EXT2_FLAG_IGNORE_CSUM_ERRORS   0x200000
 #define EXT2_FLAG_SHARE_DUP            0x400000
 #define EXT2_FLAG_IGNORE_SB_ERRORS     0x800000
+#define EXT2_FLAG_BBITMAP_TAIL_PROBLEM 0x1000000
+#define EXT2_FLAG_IBITMAP_TAIL_PROBLEM 0x2000000
 
 /*
  * Special flag in the ext2 inode i_flag field that means that this is

diff --git a/lib/ext2fs/rw_bitmaps.c b/lib/ext2fs/rw_bitmaps.c
index e86bacd..f1c4188 100644 (file)
--- a/lib/ext2fs/rw_bitmaps.c
+++ b/lib/ext2fs/rw_bitmaps.c
@@ -195,6 +195,16 @@ static errcode_t mark_uninit_bg_group_blocks(ext2_filsys fs)
        return 0;
 }
 
+static int bitmap_tail_verify(unsigned char *bitmap, int first, int last)
+{
+       int i;
+
+       for (i = first; i <= last; i++)
+               if (bitmap[i] != 0xff)
+                       return 0;
+       return 1;
+}
+
 static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
 {
        dgrp_t i;
@@ -203,6 +213,7 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
        errcode_t retval;
        int block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
        int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8;
+       int tail_flags = 0;
        int csum_flag;
        unsigned int    cnt;
        blk64_t blk;
@@ -315,6 +326,9 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
                                        EXT2_ET_BLOCK_BITMAP_CSUM_INVALID;
                                        goto cleanup;
                                }
+                               if (!bitmap_tail_verify((unsigned char *) block_bitmap,
+                                                       block_nbytes, fs->blocksize - 1))
+                                       tail_flags |= EXT2_FLAG_BBITMAP_TAIL_PROBLEM;
                        } else
                                memset(block_bitmap, 0, block_nbytes);
                        cnt = block_nbytes << 3;
@@ -347,6 +361,9 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
                                        EXT2_ET_INODE_BITMAP_CSUM_INVALID;
                                        goto cleanup;
                                }
+                               if (!bitmap_tail_verify((unsigned char *) inode_bitmap,
+                                                       inode_nbytes, fs->blocksize - 1))
+                                       tail_flags |= EXT2_FLAG_IBITMAP_TAIL_PROBLEM;
                        } else
                                memset(inode_bitmap, 0, inode_nbytes);
                        cnt = inode_nbytes << 3;
@@ -366,10 +383,15 @@ static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
        }
 
 success_cleanup:
-       if (inode_bitmap)
+       if (inode_bitmap) {
                ext2fs_free_mem(&inode_bitmap);
-       if (block_bitmap)
+               fs->flags &= ~EXT2_FLAG_IBITMAP_TAIL_PROBLEM;
+       }
+       if (block_bitmap) {
                ext2fs_free_mem(&block_bitmap);
+               fs->flags &= ~EXT2_FLAG_BBITMAP_TAIL_PROBLEM;
+       }
+       fs->flags |= tail_flags;
        return 0;
 
 cleanup:

diff --git a/tests/f_bitmaps/expect.1 b/tests/f_bitmaps/expect.1
index 715984d..2e91113 100644 (file)
--- a/tests/f_bitmaps/expect.1
+++ b/tests/f_bitmaps/expect.1
@@ -11,6 +11,8 @@ Fix? yes
 Inode bitmap differences:  +11 -15
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/32 files (9.1% non-contiguous), 22/100 blocks

diff --git a/tests/f_dup/expect.1 b/tests/f_dup/expect.1
index 075e62c..635a0df 100644 (file)
--- a/tests/f_dup/expect.1
+++ b/tests/f_dup/expect.1
@@ -30,6 +30,8 @@ Fix? yes
 Free blocks count wrong (62, counted=60).
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 Padding at end of block bitmap is not set. Fix? yes
 
 

diff --git a/tests/f_dup2/expect.1 b/tests/f_dup2/expect.1
index 69aa21b..04d7304 100644 (file)
--- a/tests/f_dup2/expect.1
+++ b/tests/f_dup2/expect.1
@@ -37,6 +37,8 @@ Fix? yes
 Free blocks count wrong (26, counted=22).
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 Padding at end of block bitmap is not set. Fix? yes
 
 

diff --git a/tests/f_dup3/expect.1 b/tests/f_dup3/expect.1
index eab75a8..5f79cb8 100644 (file)
--- a/tests/f_dup3/expect.1
+++ b/tests/f_dup3/expect.1
@@ -39,6 +39,8 @@ Fix? yes
 Free blocks count wrong (20, counted=19).
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 16/16 files (25.0% non-contiguous), 81/100 blocks

diff --git a/tests/f_end-bitmap/expect.1 b/tests/f_end-bitmap/expect.1
index 87e2fd6..85c7e67 100644 (file)
--- a/tests/f_end-bitmap/expect.1
+++ b/tests/f_end-bitmap/expect.1
@@ -8,6 +8,8 @@ Pass 5: Checking group summary information
 Free blocks count wrong for group #0 (44, counted=63).
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 Padding at end of block bitmap is not set. Fix? yes
 
 

diff --git a/tests/f_illbbitmap/expect.1 b/tests/f_illbbitmap/expect.1
index 8746d23..40996cd 100644 (file)
--- a/tests/f_illbbitmap/expect.1
+++ b/tests/f_illbbitmap/expect.1
@@ -22,6 +22,8 @@ Fix? yes
 Inode bitmap differences:  -(12--21)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/32 files (0.0% non-contiguous), 22/100 blocks

diff --git a/tests/f_illibitmap/expect.1 b/tests/f_illibitmap/expect.1
index 5bae25d..bf21df7 100644 (file)
--- a/tests/f_illibitmap/expect.1
+++ b/tests/f_illibitmap/expect.1
@@ -19,6 +19,8 @@ Pass 5: Checking group summary information
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/32 files (0.0% non-contiguous), 22/100 blocks

diff --git a/tests/f_illitable_flexbg/expect.1 b/tests/f_illitable_flexbg/expect.1
index fa42a0f..4ac1246 100644 (file)
--- a/tests/f_illitable_flexbg/expect.1
+++ b/tests/f_illitable_flexbg/expect.1
@@ -18,6 +18,8 @@ Pass 5: Checking group summary information
 Inode bitmap differences:  -(65--128)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 12/256 files (0.0% non-contiguous), 31163/32768 blocks

diff --git a/tests/f_lpf/expect.1 b/tests/f_lpf/expect.1
index 4f2853c..6ef996b 100644 (file)
--- a/tests/f_lpf/expect.1
+++ b/tests/f_lpf/expect.1
@@ -42,6 +42,8 @@ Fix? yes
 Free inodes count wrong (1, counted=0).
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 16/16 files (12.5% non-contiguous), 67/100 blocks

diff --git a/tests/f_overfsblks/expect.1 b/tests/f_overfsblks/expect.1
index e5b93f0..bc8f2a8 100644 (file)
--- a/tests/f_overfsblks/expect.1
+++ b/tests/f_overfsblks/expect.1
@@ -13,6 +13,8 @@ Pass 5: Checking group summary information
 Inode bitmap differences:  -(12--21)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/32 files (0.0% non-contiguous), 22/100 blocks

diff --git a/tests/f_super_bad_csum/expect.1 b/tests/f_super_bad_csum/expect.1
index 25ced5c..12adee9 100644 (file)
--- a/tests/f_super_bad_csum/expect.1
+++ b/tests/f_super_bad_csum/expect.1
@@ -5,8 +5,8 @@ Pass 2: Checking directory structure
 Pass 3: Checking directory connectivity
 Pass 4: Checking reference counts
 Pass 5: Checking group summary information
-Inode bitmap differences: Group 1 inode bitmap does not match checksum.
-FIXED.
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/1024 files (0.0% non-contiguous), 1557/16384 blocks

diff --git a/tests/j_corrupt_ext_jnl_sb_csum/expect b/tests/j_corrupt_ext_jnl_sb_csum/expect
index 70a4fe7..4212a00 100644 (file)
--- a/tests/j_corrupt_ext_jnl_sb_csum/expect
+++ b/tests/j_corrupt_ext_jnl_sb_csum/expect
@@ -12,6 +12,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/128 files (0.0% non-contiguous), 66/2048 blocks

diff --git a/tests/j_ext_long_trans/expect b/tests/j_ext_long_trans/expect
index d379610..ea3c87f 100644 (file)
--- a/tests/j_ext_long_trans/expect
+++ b/tests/j_ext_long_trans/expect
@@ -98,6 +98,8 @@ Fix? yes
 Free inodes count wrong (16372, counted=16373).
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/16384 files (0.0% non-contiguous), 6228/262144 blocks

diff --git a/tests/j_long_trans/expect b/tests/j_long_trans/expect
index 7a17541..82b3caf 100644 (file)
--- a/tests/j_long_trans/expect
+++ b/tests/j_long_trans/expect
@@ -96,6 +96,8 @@ Fix? yes
 Free inodes count wrong (16372, counted=16373).
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 Recreate journal? yes
 
 Creating journal (8192 blocks):  Done.

diff --git a/tests/j_long_trans_mcsum_32bit/expect b/tests/j_long_trans_mcsum_32bit/expect
index a808d9f..ffae07a 100644 (file)
--- a/tests/j_long_trans_mcsum_32bit/expect
+++ b/tests/j_long_trans_mcsum_32bit/expect
@@ -135,6 +135,8 @@ Fix? yes
 Free inodes count wrong (32756, counted=32757).
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 Recreate journal? yes
 
 Creating journal (16384 blocks):  Done.

diff --git a/tests/j_long_trans_mcsum_64bit/expect b/tests/j_long_trans_mcsum_64bit/expect
index 76e109a..e891def 100644 (file)
--- a/tests/j_long_trans_mcsum_64bit/expect
+++ b/tests/j_long_trans_mcsum_64bit/expect
@@ -134,6 +134,8 @@ Fix? yes
 Free inodes count wrong (32756, counted=32757).
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 Recreate journal? yes
 
 Creating journal (16384 blocks):  Done.

diff --git a/tests/j_recover_csum2_32bit/expect.1 b/tests/j_recover_csum2_32bit/expect.1
index 491784a..fdbda36 100644 (file)
--- a/tests/j_recover_csum2_32bit/expect.1
+++ b/tests/j_recover_csum2_32bit/expect.1
@@ -10,6 +10,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/8192 files (0.0% non-contiguous), 7739/131072 blocks

diff --git a/tests/j_recover_csum2_64bit/expect.1 b/tests/j_recover_csum2_64bit/expect.1
index 491784a..fdbda36 100644 (file)
--- a/tests/j_recover_csum2_64bit/expect.1
+++ b/tests/j_recover_csum2_64bit/expect.1
@@ -10,6 +10,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/8192 files (0.0% non-contiguous), 7739/131072 blocks

diff --git a/tests/j_short_trans/expect b/tests/j_short_trans/expect
index bcc8fe8..2bd0e50 100644 (file)
--- a/tests/j_short_trans/expect
+++ b/tests/j_short_trans/expect
@@ -32,6 +32,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/16384 files (0.0% non-contiguous), 5164/65536 blocks

diff --git a/tests/j_short_trans_64bit/expect b/tests/j_short_trans_64bit/expect
index f9971eb..808dc61 100644 (file)
--- a/tests/j_short_trans_64bit/expect
+++ b/tests/j_short_trans_64bit/expect
@@ -34,6 +34,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/16384 files (0.0% non-contiguous), 5196/65536 blocks

diff --git a/tests/j_short_trans_mcsum_64bit/expect b/tests/j_short_trans_mcsum_64bit/expect
index d876ff0..d73e282 100644 (file)
--- a/tests/j_short_trans_mcsum_64bit/expect
+++ b/tests/j_short_trans_mcsum_64bit/expect
@@ -34,6 +34,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/32768 files (0.0% non-contiguous), 6353/131072 blocks

diff --git a/tests/j_short_trans_old_csum/expect b/tests/j_short_trans_old_csum/expect
index 29ac27f..6cf06d4 100644 (file)
--- a/tests/j_short_trans_old_csum/expect
+++ b/tests/j_short_trans_old_csum/expect
@@ -34,6 +34,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/16384 files (0.0% non-contiguous), 5164/65536 blocks

diff --git a/tests/j_short_trans_open_recover/expect b/tests/j_short_trans_open_recover/expect
index be6e363..3e86819 100644 (file)
--- a/tests/j_short_trans_open_recover/expect
+++ b/tests/j_short_trans_open_recover/expect
@@ -37,6 +37,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/16384 files (0.0% non-contiguous), 5164/65536 blocks

diff --git a/tests/j_short_trans_recover/expect b/tests/j_short_trans_recover/expect
index 7586733..508858c 100644 (file)
--- a/tests/j_short_trans_recover/expect
+++ b/tests/j_short_trans_recover/expect
@@ -34,6 +34,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/16384 files (0.0% non-contiguous), 5164/65536 blocks

diff --git a/tests/j_short_trans_recover_mcsum_64bit/expect b/tests/j_short_trans_recover_mcsum_64bit/expect
index 9cc3309..8c637f1 100644 (file)
--- a/tests/j_short_trans_recover_mcsum_64bit/expect
+++ b/tests/j_short_trans_recover_mcsum_64bit/expect
@@ -36,6 +36,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/32768 files (0.0% non-contiguous), 6353/131072 blocks

diff --git a/tests/t_replay_and_set/expect b/tests/t_replay_and_set/expect
index f63a73a..3e19d92 100644 (file)
--- a/tests/t_replay_and_set/expect
+++ b/tests/t_replay_and_set/expect
@@ -30,6 +30,8 @@ Fix? yes
 Inode bitmap differences:  +(1--11)
 Fix? yes
 
+Padding at end of inode bitmap is not set. Fix? yes
+
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
 test_filesys: 11/16384 files (0.0% non-contiguous), 5164/65536 blocks