[PATCH 18/54] e2fsck: improve the inline directory detector

["Darrick J. Wong" <darrick.wong@oracle.com>]

Strengthen the checks that guess if the inode we're looking at is an
inline directory.  The current check sweeps up any inline inode if
its length is a multiple of four; now we'll at least try to see if
there's the beginning of a valid directory entry.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 e2fsck/pass1.c                      |   23 +++++++++++++++++++++++
 tests/f_inlinedata_repair/expect.1  |   26 +++-----------------------
 tests/f_inlinedata_repair/expect.2  |    2 +-
 tests/f_inlinedir_detector/expect.1 |   20 ++++++++++++++++++++
 tests/f_inlinedir_detector/expect.2 |    7 +++++++
 tests/f_inlinedir_detector/image.gz |  Bin
 tests/f_inlinedir_detector/name     |    1 +
 7 files changed, 55 insertions(+), 24 deletions(-)
 create mode 100644 tests/f_inlinedir_detector/expect.1
 create mode 100644 tests/f_inlinedir_detector/expect.2
 create mode 100644 tests/f_inlinedir_detector/image.gz
 create mode 100644 tests/f_inlinedir_detector/name


diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index 69a9ac1..9f22826 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -537,6 +537,9 @@ static void check_is_really_dir(e2fsck_t ctx, struct problem_context *pctx,
 			 EXT4_FEATURE_INCOMPAT_INLINE_DATA);
 	if (inlinedata_fs && (inode->i_flags & EXT4_INLINE_DATA_FL)) {
 		size_t size;
+		__u32 dotdot;
+		unsigned int rec_len;
+		struct ext2_dir_entry de;
 
 		if (ext2fs_inline_data_size(ctx->fs, pctx->ino, &size))
 			return;
@@ -546,6 +549,26 @@ static void check_is_really_dir(e2fsck_t ctx, struct problem_context *pctx,
 		 */
 		if (size & 3)
 			return;
+		/*
+		 * If the first 10 bytes don't look like a directory entry,
+		 * it's probably not a directory.
+		 */
+		memcpy(&dotdot, inode->i_block, sizeof(dotdot));
+		memcpy(&de, ((char *)inode->i_block) + EXT4_INLINE_DATA_DOTDOT_SIZE,
+		       EXT2_DIR_REC_LEN(0));
+		dotdot = ext2fs_le32_to_cpu(dotdot);
+		de.inode = ext2fs_le32_to_cpu(de.inode);
+		de.rec_len = ext2fs_le16_to_cpu(de.rec_len);
+		ext2fs_get_rec_len(ctx->fs, &de, &rec_len);
+		if (dotdot >= ctx->fs->super->s_inodes_count ||
+		    (dotdot < EXT2_FIRST_INO(ctx->fs->super) &&
+		     dotdot != EXT2_ROOT_INO) ||
+		    de.inode >= ctx->fs->super->s_inodes_count ||
+		    (de.inode < EXT2_FIRST_INO(ctx->fs->super) &&
+		     de.inode != 0) ||
+		    rec_len > EXT4_MIN_INLINE_DATA_SIZE -
+			      EXT4_INLINE_DATA_DOTDOT_SIZE)
+			return;
 		/* device files never have a "system.data" entry */
 		goto isdir;
 	} else if (extent_fs && (inode->i_flags & EXT4_EXTENTS_FL)) {
diff --git a/tests/f_inlinedata_repair/expect.1 b/tests/f_inlinedata_repair/expect.1
index faba192..cc220ba 100644
--- a/tests/f_inlinedata_repair/expect.1
+++ b/tests/f_inlinedata_repair/expect.1
@@ -8,11 +8,6 @@ Inode 24, i_size is 59, should be 60.  Fix? yes
 Inode 28 is a unknown file type with mode 00 but it looks like it is really a directory.
 Fix? yes
 
-Inode 36 is a unknown file type with mode 00 but it looks like it is really a directory.
-Fix? yes
-
-Inode 36, i_size is 5, should be 60.  Fix? yes
-
 Pass 2: Checking directory structure
 Directory inode 20, block #0, offset 4: directory corrupted
 Salvage? yes
@@ -26,26 +21,16 @@ Salvage? yes
 Directory inode 32, block #0, offset 4: directory corrupted
 Salvage? yes
 
-Entry '..' in ??? (36) has invalid inode #: 1633774699.
-Clear? yes
-
-Directory inode 36, block #0, offset 4: directory corrupted
-Salvage? yes
-
 Symlink /3 (inode #14) is invalid.
 Clear? yes
 
 Inode 38 (/B) has invalid mode (00).
 Clear? yes
 
-Entry 'A' in / (2) has an incorrect filetype (was 1, should be 2).
-Fix? yes
+Inode 36 (/A) has invalid mode (00).
+Clear? yes
 
 Pass 3: Checking directory connectivity
-'..' in /A (36) is ??? (1633774699), should be / (2).
-Fix? yes
-
-Error while adjusting inode count on inode 0
 Pass 4: Checking reference counts
 Unattached zero-length inode 22.  Clear? yes
 
@@ -63,13 +48,8 @@ Unattached zero-length inode 34.  Clear? yes
 
 Unattached zero-length inode 35.  Clear? yes
 
-Inode 36 ref count is 1, should be 2.  Fix? yes
-
 Pass 5: Checking group summary information
-Directories count wrong for group #0 (7, counted=8).
-Fix? yes
-
 
 test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
-test_filesys: 28/128 files (0.0% non-contiguous), 18/512 blocks
+test_filesys: 27/128 files (0.0% non-contiguous), 18/512 blocks
 Exit status is 1
diff --git a/tests/f_inlinedata_repair/expect.2 b/tests/f_inlinedata_repair/expect.2
index 519f21d..2c400a5 100644
--- a/tests/f_inlinedata_repair/expect.2
+++ b/tests/f_inlinedata_repair/expect.2
@@ -3,5 +3,5 @@ Pass 2: Checking directory structure
 Pass 3: Checking directory connectivity
 Pass 4: Checking reference counts
 Pass 5: Checking group summary information
-test_filesys: 28/128 files (0.0% non-contiguous), 18/512 blocks
+test_filesys: 27/128 files (0.0% non-contiguous), 18/512 blocks
 Exit status is 0
diff --git a/tests/f_inlinedir_detector/expect.1 b/tests/f_inlinedir_detector/expect.1
new file mode 100644
index 0000000..72b7519
--- /dev/null
+++ b/tests/f_inlinedir_detector/expect.1
@@ -0,0 +1,20 @@
+Pass 1: Checking inodes, blocks, and sizes
+Special (device/socket/fifo) file (inode 12) has extents
+or inline-data flag set.  Clear? yes
+
+Special (device/socket/fifo) inode 12 has non-zero size.  Fix? yes
+
+Inode 13 is a named pipe but it looks like it is really a directory.
+Fix? yes
+
+Pass 2: Checking directory structure
+Entry 'moo' in / (2) has an incorrect filetype (was 1, should be 5).
+Fix? yes
+
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 13/128 files (0.0% non-contiguous), 17/512 blocks
+Exit status is 1
diff --git a/tests/f_inlinedir_detector/expect.2 b/tests/f_inlinedir_detector/expect.2
new file mode 100644
index 0000000..06886a4
--- /dev/null
+++ b/tests/f_inlinedir_detector/expect.2
@@ -0,0 +1,7 @@
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+test_filesys: 13/128 files (0.0% non-contiguous), 17/512 blocks
+Exit status is 0
diff --git a/tests/f_inlinedir_detector/image.gz b/tests/f_inlinedir_detector/image.gz
new file mode 100644
index 0000000000000000000000000000000000000000..34b4518849cd60d83890b5c69ff6a0aefaa54d57
GIT binary patch
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diff --git a/tests/f_inlinedir_detector/name b/tests/f_inlinedir_detector/name
new file mode 100644
index 0000000..3368af5
--- /dev/null
+++ b/tests/f_inlinedir_detector/name
@@ -0,0 +1 @@
+detect inline dirs correctly