libext2fs-handle-inline-data-in-dir-iterator-function

libext2fs: handle inline data in dir iterator function

From: Zheng Liu <wenqing.lz@taobao.com>

Inline_data is handled in dir iterator because a lot of commands use
this function to traverse directory entries in debugfs.  We need to
handle inline_data individually because inline_data is saved in two
places.  One is in i_block, and another is in ibody extended attribute.

After applied this commit, the following commands in debugfs can
support the inline_data feature:
	- cd
	- chroot
	- link*
	- ls
	- ncheck
	- pwd
	- unlink

* TODO: Inline_data doesn't expand to ibody extended attribute because
  link command doesn't handle DIR_NO_SPACE error until now.  But if we
  have already expanded inline data to ibody ea area, link command can
  occupy this space.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
diff --git a/lib/ext2fs/Makefile.in b/lib/ext2fs/Makefile.in
index e1e6216..4d011c9 100644
--- a/lib/ext2fs/Makefile.in
+++ b/lib/ext2fs/Makefile.in
@@ -59,6 +59,7 @@ OBJS= $(DEBUGFS_LIB_OBJS) $(RESIZE_LIB_OBJS) $(E2IMAGE_LIB_OBJS) \
 	ind_block.o \
 	initialize.o \
 	inline.o \
+	inline_data.o \
 	inode.o \
 	io_manager.o \
 	ismounted.o \
@@ -133,6 +134,7 @@ SRCS= ext2_err.c \
 	$(srcdir)/ind_block.c \
 	$(srcdir)/initialize.c \
 	$(srcdir)/inline.c \
+	$(srcdir)/inline_data.c	\
 	$(srcdir)/inode.c \
 	$(srcdir)/inode_io.c \
 	$(srcdir)/imager.c \
@@ -758,6 +760,12 @@ inline.o: $(srcdir)/inline.c $(top_builddir)/lib/config.h \
  $(srcdir)/ext2_fs.h $(srcdir)/ext3_extents.h $(top_srcdir)/lib/et/com_err.h \
  $(srcdir)/ext2_io.h $(top_builddir)/lib/ext2fs/ext2_err.h \
  $(srcdir)/ext2_ext_attr.h $(srcdir)/bitops.h
+inline_data.o: $(srcdir)/inline_data.c $(top_builddir)/lib/config.h \
+ $(top_builddir)/lib/dirpaths.h $(srcdir)/ext2_fs.h \
+ $(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fs.h \
+ $(srcdir)/ext2_fs.h $(srcdir)/ext3_extents.h $(top_srcdir)/lib/et/com_err.h \
+ $(srcdir)/ext2_io.h $(top_builddir)/lib/ext2fs/ext2_err.h \
+ $(srcdir)/ext2_ext_attr.h $(srcdir)/bitops.h
 inode.o: $(srcdir)/inode.c $(top_builddir)/lib/config.h \
  $(top_builddir)/lib/dirpaths.h $(srcdir)/ext2_fs.h \
  $(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fsP.h \
diff --git a/lib/ext2fs/Makefile.pq b/lib/ext2fs/Makefile.pq
index 2f7b654..89082a7 100644
--- a/lib/ext2fs/Makefile.pq
+++ b/lib/ext2fs/Makefile.pq
@@ -27,6 +27,7 @@ OBJS= 	alloc.obj \
 	icount.obj \
 	initialize.obj \
 	inline.obj \
+	inline_data.obj \
 	inode.obj \
 	ismounted.obj \
 	link.obj \
diff --git a/lib/ext2fs/dir_iterate.c b/lib/ext2fs/dir_iterate.c
index 8be0ac2..1624371 100644
--- a/lib/ext2fs/dir_iterate.c
+++ b/lib/ext2fs/dir_iterate.c
@@ -127,6 +127,12 @@ errcode_t ext2fs_dir_iterate2(ext2_filsys fs,
 				       ext2fs_process_dir_block, &ctx);
 	if (!block_buf)
 		ext2fs_free_mem(&ctx.buf);
+	if (retval == EXT2_ET_INLINE_DATA_CANT_ITERATE) {
+		ctx.flags |= DIRENT_FLAG_INCLUDE_INLINE_DATA;
+		retval = ext2fs_inline_data_dir_iterate(fs, dir,
+						ext2fs_process_dir_block,
+						&ctx);
+	}
 	if (retval)
 		return retval;
 	return ctx.errcode;
@@ -189,30 +195,40 @@ int ext2fs_process_dir_block(ext2_filsys fs,
 	int		ret = 0;
 	int		changed = 0;
 	int		do_abort = 0;
-	unsigned int	rec_len, size;
+	unsigned int	rec_len, size, buflen;
 	int		entry;
 	struct ext2_dir_entry *dirent;
 	int		csum_size = 0;
+	int		inline_data;
+	errcode_t	retval = 0;
 
 	if (blockcnt < 0)
 		return 0;
 
 	entry = blockcnt ? DIRENT_OTHER_FILE : DIRENT_DOT_FILE;
 
-	ctx->errcode = ext2fs_read_dir_block4(fs, *blocknr, ctx->buf, 0,
-					      ctx->dir);
-	if (ctx->errcode)
-		return BLOCK_ABORT;
+	/* If a dir has inline data, we don't need to read block */
+	inline_data = !!(ctx->flags & DIRENT_FLAG_INCLUDE_INLINE_DATA);
+	if (!inline_data) {
+		ctx->errcode = ext2fs_read_dir_block4(fs, *blocknr, ctx->buf, 0,
+						      ctx->dir);
+		if (ctx->errcode)
+			return BLOCK_ABORT;
+		/* If we handle a normal dir, we traverse the entire block */
+		buflen = fs->blocksize;
+	} else {
+		buflen = ctx->buflen;
+	}
 
 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
 					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
 		csum_size = sizeof(struct ext2_dir_entry_tail);
 
-	while (offset < fs->blocksize) {
+	while (offset < buflen) {
 		dirent = (struct ext2_dir_entry *) (ctx->buf + offset);
 		if (ext2fs_get_rec_len(fs, dirent, &rec_len))
 			return BLOCK_ABORT;
-		if (((offset + rec_len) > fs->blocksize) ||
+		if (((offset + rec_len) > buflen) ||
 		    (rec_len < 8) ||
 		    ((rec_len % 4) != 0) ||
 		    ((ext2fs_dirent_name_len(dirent)+8) > rec_len)) {
@@ -220,7 +236,13 @@ int ext2fs_process_dir_block(ext2_filsys fs,
 			return BLOCK_ABORT;
 		}
 		if (!dirent->inode) {
-			if ((offset == fs->blocksize - csum_size) &&
+			/*
+			 * We just need to check metadata_csum when this
+			 * dir hasn't inline data.  That means that 'buflen'
+			 * should be blocksize.
+			 */
+			if (!inline_data &&
+			    (offset == buflen - csum_size) &&
 			    (dirent->rec_len == csum_size) &&
 			    (dirent->name_len == EXT2_DIR_NAME_LEN_CSUM)) {
 				if (!(ctx->flags & DIRENT_FLAG_INCLUDE_CSUM))
@@ -234,7 +256,7 @@ int ext2fs_process_dir_block(ext2_filsys fs,
 				  (next_real_entry > offset) ?
 				  DIRENT_DELETED_FILE : entry,
 				  dirent, offset,
-				  fs->blocksize, ctx->buf,
+				  buflen, ctx->buf,
 				  ctx->priv_data);
 		if (entry < DIRENT_OTHER_FILE)
 			entry++;
@@ -272,13 +294,21 @@ next:
 	}
 
 	if (changed) {
-		ctx->errcode = ext2fs_write_dir_block4(fs, *blocknr, ctx->buf,
-						       0, ctx->dir);
-		if (ctx->errcode)
-			return BLOCK_ABORT;
+		if (!inline_data) {
+			ctx->errcode = ext2fs_write_dir_block4(fs, *blocknr,
+							       ctx->buf,
+							       0, ctx->dir);
+			if (ctx->errcode)
+				return BLOCK_ABORT;
+		} else {
+			/*
+			 * return BLOCK_CHANGED to notify caller that inline
+			 * data has been changed
+			 */
+			retval = BLOCK_CHANGED;
+		}
 	}
 	if (do_abort)
-		return BLOCK_ABORT;
-	return 0;
+		return retval | BLOCK_ABORT;
+	return retval;
 }
-
diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in
index b819a90..0781145 100644
--- a/lib/ext2fs/ext2_err.et.in
+++ b/lib/ext2fs/ext2_err.et.in
@@ -500,4 +500,7 @@ ec	EXT2_ET_EA_KEY_NOT_FOUND,
 ec	EXT2_ET_EA_NO_SPACE,
 	"Insufficient space to store extended attribute data"
 
+ec	EXT2_ET_NO_INLINE_DATA,
+	"Inode doesn't have inline data"
+
 	end
diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index 6a28d55..5ab16ae 100644
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h
@@ -914,4 +914,14 @@ struct mmp_struct {
  */
 #define EXT4_MMP_MIN_CHECK_INTERVAL     5
 
+/*
+ * Minimum size of inline data.
+ */
+#define EXT4_MIN_INLINE_DATA_SIZE	((sizeof(__u32) * EXT2_N_BLOCKS))
+
+/*
+ * Size of a parent inode in inline data directory.
+ */
+#define EXT4_INLINE_DATA_DOTDOT_SIZE	(4)
+
 #endif	/* _LINUX_EXT2_FS_H */
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index e251435..c5b73fd 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -438,6 +438,7 @@ struct ext2_extent_info {
 #define DIRENT_FLAG_INCLUDE_EMPTY	1
 #define DIRENT_FLAG_INCLUDE_REMOVED	2
 #define DIRENT_FLAG_INCLUDE_CSUM	4
+#define DIRENT_FLAG_INCLUDE_INLINE_DATA 8
 
 #define DIRENT_DOT_FILE		1
 #define DIRENT_DOT_DOT_FILE	2
diff --git a/lib/ext2fs/ext2fsP.h b/lib/ext2fs/ext2fsP.h
index 80d2d0a..5ab6084 100644
--- a/lib/ext2fs/ext2fsP.h
+++ b/lib/ext2fs/ext2fsP.h
@@ -50,6 +50,7 @@ struct dir_context {
 	ext2_ino_t		dir;
 	int		flags;
 	char		*buf;
+	unsigned int	buflen;
 	int (*func)(ext2_ino_t	dir,
 		    int	entry,
 		    struct ext2_dir_entry *dirent,
@@ -87,6 +88,16 @@ extern int ext2fs_process_dir_block(ext2_filsys  	fs,
 				    int			ref_offset,
 				    void		*priv_data);
 
+extern errcode_t ext2fs_inline_data_dir_iterate(ext2_filsys fs,
+				      ext2_ino_t ino,
+				      int (*func)(ext2_filsys fs,
+						  blk64_t     *blocknr,
+						  e2_blkcnt_t blockcnt,
+						  blk64_t     ref_blk,
+						  int	      ref_offset,
+						  void	      *priv_data),
+				      void *priv_data);
+
 /* Generic numeric progress meter */
 
 struct ext2fs_numeric_progress_struct {
diff --git a/lib/ext2fs/inline_data.c b/lib/ext2fs/inline_data.c
new file mode 100644
index 0000000..cc2954d
--- /dev/null
+++ b/lib/ext2fs/inline_data.c
@@ -0,0 +1,175 @@
+/*
+ * inline_data.c --- data in inode
+ *
+ * Copyright (C) 2012 Zheng Liu <wenqing.lz@taobao.com>
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU library
+ * General Public License, version 2.
+ * %End-Header%
+ */
+
+#include "config.h"
+#include <stdio.h>
+#include <time.h>
+
+#include "ext2_fs.h"
+#include "ext2_ext_attr.h"
+
+#include "ext2fs.h"
+#include "ext2fsP.h"
+
+struct ext2_inline_data {
+	ext2_filsys fs;
+	ext2_ino_t ino;
+	size_t ea_size;	/* the size of inline data in ea area */
+	char *ea_data;
+};
+
+static errcode_t ext2fs_inline_data_ea_set(struct ext2_inline_data *data)
+{
+	struct ext2_xattr_handle *handle;
+	errcode_t retval;
+
+	retval = ext2fs_xattrs_open(data->fs, data->ino, &handle);
+	if (retval)
+		return retval;
+
+	retval = ext2fs_xattrs_read(handle);
+	if (retval)
+		goto err;
+
+	retval = ext2fs_xattr_set(handle, "system.data",
+				  data->ea_data, data->ea_size);
+	if (retval)
+		goto err;
+
+	retval = ext2fs_xattrs_write(handle);
+
+err:
+	(void) ext2fs_xattrs_close(&handle);
+	return retval;
+}
+
+errcode_t ext2fs_inline_data_ea_get(struct ext2_inline_data *data)
+{
+	struct ext2_xattr_handle *handle;
+	errcode_t retval;
+
+	data->ea_size = 0;
+	data->ea_data = 0;
+
+	retval = ext2fs_xattrs_open(data->fs, data->ino, &handle);
+	if (retval)
+		return retval;
+
+	retval = ext2fs_xattrs_read(handle);
+	if (retval)
+		goto err;
+
+	retval = ext2fs_xattr_get(handle, "system.data",
+				  (void **)&data->ea_data, &data->ea_size);
+	if (retval)
+		goto err;
+
+err:
+	(void) ext2fs_xattrs_close(&handle);
+	return retval;
+}
+
+
+errcode_t ext2fs_inline_data_dir_iterate(ext2_filsys fs,
+			       ext2_ino_t ino,
+			       int (*func)(ext2_filsys fs,
+					   blk64_t     *blocknr,
+					   e2_blkcnt_t blockcnt,
+					   blk64_t     ref_blk,
+					   int         ref_offset,
+					   void        *priv_data),
+			       void *priv_data)
+{
+	struct dir_context *ctx;
+	struct ext2_inode inode;
+	struct ext2_dir_entry dirent;
+	struct ext2_inline_data data;
+	errcode_t retval = 0;
+	e2_blkcnt_t blockcnt = 0;
+
+	ctx = (struct dir_context *)priv_data;
+
+	retval = ext2fs_read_inode(fs, ino, &inode);
+	if (retval)
+		goto out;
+
+	if (!(inode.i_flags & EXT4_INLINE_DATA_FL))
+		return EXT2_ET_NO_INLINE_DATA;
+
+	if (!LINUX_S_ISDIR(inode.i_mode)) {
+		retval = EXT2_ET_NO_DIRECTORY;
+		goto out;
+	}
+
+	/* we first check '.' and '..' dir */
+	dirent.inode = ino;
+	dirent.name_len = 1;
+	ext2fs_set_rec_len(fs, EXT2_DIR_REC_LEN(2), &dirent);
+	dirent.name[0] = '.';
+	dirent.name[1] = '\0';
+	ctx->buf = (char *)&dirent;
+	ext2fs_get_rec_len(fs, &dirent, &ctx->buflen);
+	retval |= (*func)(fs, 0, blockcnt++, 0, 0, priv_data);
+	if (retval & BLOCK_ABORT)
+		goto out;
+
+	dirent.inode = ext2fs_le32_to_cpu(inode.i_block[0]);
+	dirent.name_len = 2;
+	ext2fs_set_rec_len(fs, EXT2_DIR_REC_LEN(3), &dirent);
+	dirent.name[0] = '.';
+	dirent.name[1] = '.';
+	dirent.name[2] = '\0';
+	ctx->buf = (char *)&dirent;
+	ext2fs_get_rec_len(fs, &dirent, &ctx->buflen);
+	retval |= (*func)(fs, 0, blockcnt++, 0, 0, priv_data);
+	if (retval & BLOCK_CHANGED) {
+		errcode_t err;
+
+		inode.i_block[0] = ext2fs_cpu_to_le32(dirent.inode);
+		err = ext2fs_write_inode(fs, ino, &inode);
+		if (err)
+			goto out;
+	}
+	if (retval & BLOCK_ABORT)
+		goto out;
+
+	ctx->buf = (char *)inode.i_block + EXT4_INLINE_DATA_DOTDOT_SIZE;
+	ctx->buflen = EXT4_MIN_INLINE_DATA_SIZE - EXT4_INLINE_DATA_DOTDOT_SIZE;
+	retval |= (*func)(fs, 0, blockcnt++, 0, 0, priv_data);
+	if (retval & BLOCK_CHANGED) {
+		errcode_t err;
+
+		err = ext2fs_write_inode(fs, ino, &inode);
+		if (err)
+			goto out;
+	}
+	if (retval & BLOCK_ABORT)
+		goto out;
+
+	data.fs = fs;
+	data.ino = ino;
+	retval = ext2fs_inline_data_ea_get(&data);
+	if (retval)
+		goto out;
+	if (data.ea_size > 0) {
+		ctx->buf = data.ea_data;
+		ctx->buflen = data.ea_size;
+		retval |= (*func)(fs, 0, blockcnt++, 0, 0, priv_data);
+		if (retval & BLOCK_CHANGED)
+			ext2fs_inline_data_ea_set(&data);
+		ext2fs_free_mem(&data.ea_data);
+		ctx->buf = 0;
+	}
+
+out:
+	retval |= BLOCK_ERROR;
+	return retval & BLOCK_ERROR ? ctx->errcode : 0;
+}
diff --git a/lib/ext2fs/swapfs.c b/lib/ext2fs/swapfs.c
index 1295e81..cfbe5dd 100644
--- a/lib/ext2fs/swapfs.c
+++ b/lib/ext2fs/swapfs.c
@@ -207,6 +207,7 @@ void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
 {
 	unsigned i, has_data_blocks, extra_isize, attr_magic;
 	int has_extents = 0;
+	int has_inline_data = 0;
 	int islnk = 0;
 	__u32 *eaf, *eat;
 
@@ -233,12 +234,19 @@ void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
 					   (struct ext2_inode *) t);
 	if (hostorder && (f->i_flags & EXT4_EXTENTS_FL))
 		has_extents = 1;
+	if (hostorder && (f->i_flags & EXT4_INLINE_DATA_FL))
+		has_inline_data = 1;
 	t->i_flags = ext2fs_swab32(f->i_flags);
 	if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL))
 		has_extents = 1;
+	if (!hostorder && (f->i_flags & EXT4_INLINE_DATA_FL))
+		has_inline_data = 1;
 	t->i_dir_acl = ext2fs_swab32(f->i_dir_acl);
-	/* extent data are swapped on access, not here */
-	if (!has_extents && (!islnk || has_data_blocks)) {
+	/*
+	 * Extent data are swapped on access, not here
+	 * Inline data are not swapped beside parent ino is accessed
+	 */
+	if (!has_extents && !has_inline_data && (!islnk || has_data_blocks)) {
 		for (i = 0; i < EXT2_N_BLOCKS; i++)
 			t->i_block[i] = ext2fs_swab32(f->i_block[i]);
 	} else if (t != f) {