Add support for on-line resizing ala the resize inode. This patch
is taken from Fedora Core 3's e2fsprogs 1.35-11.2.src.rpm's
e2fsprogs-resize.patch.
diff --git a/lib/ext2fs/Makefile.in b/lib/ext2fs/Makefile.in
index 0ad0078..6543e39 100644
--- a/lib/ext2fs/Makefile.in
+++ b/lib/ext2fs/Makefile.in
@@ -58,7 +58,9 @@
openfs.o \
read_bb.o \
read_bb_file.o \
+ res_gdt.o \
rw_bitmaps.o \
+ sparse.o \
swapfs.o \
unix_io.o \
unlink.o \
@@ -115,8 +117,10 @@
$(srcdir)/openfs.c \
$(srcdir)/read_bb.c \
$(srcdir)/read_bb_file.c \
+ $(srcdir)/res_gdt.c \
$(srcdir)/rs_bitmap.c \
$(srcdir)/rw_bitmaps.c \
+ $(srcdir)/sparse.c \
$(srcdir)/swapfs.c \
$(srcdir)/test_io.c \
$(srcdir)/unix_io.c \
@@ -460,6 +464,10 @@
$(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fs.h \
$(srcdir)/ext2_fs.h $(top_srcdir)/lib/et/com_err.h $(srcdir)/ext2_io.h \
$(top_builddir)/lib/ext2fs/ext2_err.h $(srcdir)/bitops.h
+res_gdt.o: $(srcdir)/res_gdt.c $(srcdir)/ext2_fs.h \
+ $(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fs.h \
+ $(top_srcdir)/lib/et/com_err.h $(srcdir)/ext2_io.h \
+ $(top_builddir)/lib/ext2fs/ext2_err.h
rs_bitmap.o: $(srcdir)/rs_bitmap.c $(srcdir)/ext2_fs.h \
$(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fs.h \
$(srcdir)/ext2_fs.h $(top_srcdir)/lib/et/com_err.h $(srcdir)/ext2_io.h \
@@ -468,6 +476,8 @@
$(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fs.h \
$(srcdir)/ext2_fs.h $(top_srcdir)/lib/et/com_err.h $(srcdir)/ext2_io.h \
$(top_builddir)/lib/ext2fs/ext2_err.h $(srcdir)/bitops.h $(srcdir)/e2image.h
+sparse.o: $(srcdir)/sparse.c $(srcdir)/ext2_fs.h \
+ $(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fs.h
swapfs.o: $(srcdir)/swapfs.c $(srcdir)/ext2_fs.h \
$(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fs.h \
$(srcdir)/ext2_fs.h $(top_srcdir)/lib/et/com_err.h $(srcdir)/ext2_io.h \
diff --git a/lib/ext2fs/alloc_sb.c b/lib/ext2fs/alloc_sb.c
index e4733c9..ef40b93 100644
--- a/lib/ext2fs/alloc_sb.c
+++ b/lib/ext2fs/alloc_sb.c
@@ -40,7 +40,8 @@
if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
old_desc_blocks = fs->super->s_first_meta_bg;
else
- old_desc_blocks = fs->desc_blocks;
+ old_desc_blocks =
+ fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
if (super_blk || (group == 0))
ext2fs_mark_block_bitmap(bmap, super_blk);
diff --git a/lib/ext2fs/closefs.c b/lib/ext2fs/closefs.c
index 71fa9e4..6fe012c 100644
--- a/lib/ext2fs/closefs.c
+++ b/lib/ext2fs/closefs.c
@@ -19,32 +19,6 @@
#include "ext2_fs.h"
#include "ext2fsP.h"
-static int test_root(int a, int b)
-{
- if (a == 0)
- return 1;
- while (1) {
- if (a == 1)
- return 1;
- if (a % b)
- return 0;
- a = a / b;
- }
-}
-
-int ext2fs_bg_has_super(ext2_filsys fs, int group_block)
-{
- if (!(fs->super->s_feature_ro_compat &
- EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER))
- return 1;
-
- if (test_root(group_block, 3) || (test_root(group_block, 5)) ||
- test_root(group_block, 7))
- return 1;
-
- return 0;
-}
-
int ext2fs_super_and_bgd_loc(ext2_filsys fs,
dgrp_t group,
blk_t *ret_super_blk,
@@ -63,7 +37,8 @@
if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
old_desc_blocks = fs->super->s_first_meta_bg;
else
- old_desc_blocks = fs->desc_blocks;
+ old_desc_blocks =
+ fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
if (group == fs->group_desc_count-1) {
numblocks = (fs->super->s_blocks_count -
diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in
index b3ada29..99ffa2e 100644
--- a/lib/ext2fs/ext2_err.et.in
+++ b/lib/ext2fs/ext2_err.et.in
@@ -287,5 +287,8 @@
ec EXT2_ET_NOT_IMAGE_FILE,
"E2image snapshot not in use"
+ec EXT2_ET_RES_GDT_BLOCKS,
+ "Too many reserved group descriptor blocks"
+
end
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 6a02127..4904a3b 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -430,6 +430,7 @@
#define EXT2_LIB_FEATURE_COMPAT_SUPP (EXT2_FEATURE_COMPAT_DIR_PREALLOC|\
EXT2_FEATURE_COMPAT_IMAGIC_INODES|\
EXT3_FEATURE_COMPAT_HAS_JOURNAL|\
+ EXT2_FEATURE_COMPAT_RESIZE_INODE|\
EXT2_FEATURE_COMPAT_DIR_INDEX|\
EXT2_FEATURE_COMPAT_EXT_ATTR)
@@ -600,14 +601,12 @@
/* closefs.c */
extern errcode_t ext2fs_close(ext2_filsys fs);
extern errcode_t ext2fs_flush(ext2_filsys fs);
-extern int ext2fs_bg_has_super(ext2_filsys fs, int group_block);
extern int ext2fs_super_and_bgd_loc(ext2_filsys fs,
dgrp_t group,
blk_t *ret_super_blk,
blk_t *ret_old_desc_blk,
blk_t *ret_new_desc_blk,
int *ret_meta_bg);
-extern void ext2fs_update_dynamic_rev(ext2_filsys fs);
/* cmp_bitmaps.c */
extern errcode_t ext2fs_compare_block_bitmap(ext2fs_block_bitmap bm1,
@@ -888,6 +887,9 @@
void (*invalid)(ext2_filsys fs,
blk_t blk));
+/* res_gdt.c */
+extern errcode_t ext2fs_create_resize_inode(ext2_filsys fs);
+
/* rs_bitmap.c */
extern errcode_t ext2fs_resize_generic_bitmap(__u32 new_end,
__u32 new_real_end,
@@ -899,6 +901,12 @@
extern errcode_t ext2fs_copy_bitmap(ext2fs_generic_bitmap src,
ext2fs_generic_bitmap *dest);
+/* sparse.c */
+extern int ext2fs_bg_has_super(ext2_filsys fs, int group_block);
+extern void ext2fs_update_dynamic_rev(ext2_filsys fs);
+extern unsigned int ext2fs_list_backups(ext2_filsys fs, unsigned *three,
+ unsigned *five, unsigned *seven);
+
/* swapfs.c */
extern void ext2fs_swap_super(struct ext2_super_block * super);
extern void ext2fs_swap_group_desc(struct ext2_group_desc *gdp);
diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
index 2ee06b5..3b80f46 100644
--- a/lib/ext2fs/initialize.c
+++ b/lib/ext2fs/initialize.c
@@ -58,6 +58,35 @@
#endif
#define EXT2_DFL_CHECKINTERVAL (86400L * 180L)
+/*
+ * Calculate the number of GDT blocks to reserve for online filesystem growth.
+ * The absolute maximum number of GDT blocks we can reserve is determined by
+ * the number of block pointers that can fit into a single block.
+ */
+static int calc_reserved_gdt_blocks(ext2_filsys fs)
+{
+ struct ext2_super_block *sb = fs->super;
+ unsigned long bpg = sb->s_blocks_per_group;
+ unsigned int gdpb = fs->blocksize / sizeof(struct ext2_group_desc);
+ unsigned long max_blocks = 0xffffffff;
+ unsigned long rsv_groups;
+ int rsv_gdb;
+
+ /* We set it at 1024x the current filesystem size, or
+ * the upper block count limit (2^32), whichever is lower.
+ */
+ if (sb->s_blocks_count < max_blocks / 1024)
+ max_blocks = sb->s_blocks_count * 1024;
+ rsv_groups = (max_blocks - sb->s_first_data_block + bpg - 1) / bpg;
+ rsv_gdb = (rsv_groups + gdpb - 1) / gdpb - fs->desc_blocks;
+ if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb))
+ rsv_gdb = EXT2_ADDR_PER_BLOCK(sb);
+ printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %lu\n",
+ max_blocks, rsv_groups, rsv_gdb);
+
+ return rsv_gdb;
+}
+
errcode_t ext2fs_initialize(const char *name, int flags,
struct ext2_super_block *param,
io_manager manager, ext2_filsys *ret_fs)
@@ -72,6 +101,7 @@
unsigned int ipg;
dgrp_t i;
blk_t numblocks;
+ int rsv_gdt;
char *buf;
if (!param || !param->s_blocks_count)
@@ -120,10 +150,14 @@
set_field(s_feature_incompat, 0);
set_field(s_feature_ro_compat, 0);
set_field(s_first_meta_bg, 0);
- if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP)
- return EXT2_ET_UNSUPP_FEATURE;
- if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP)
- return EXT2_ET_RO_UNSUPP_FEATURE;
+ if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
+ retval = EXT2_ET_UNSUPP_FEATURE;
+ goto cleanup;
+ }
+ if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) {
+ retval = EXT2_ET_RO_UNSUPP_FEATURE;
+ goto cleanup;
+ }
set_field(s_rev_level, EXT2_GOOD_OLD_REV);
if (super->s_rev_level >= EXT2_DYNAMIC_REV) {
@@ -157,8 +191,7 @@
* If we're creating an external journal device, we don't need
* to bother with the rest.
*/
- if (super->s_feature_incompat &
- EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
+ if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
fs->group_desc_count = 0;
ext2fs_mark_super_dirty(fs);
*ret_fs = fs;
@@ -170,8 +203,10 @@
super->s_first_data_block +
EXT2_BLOCKS_PER_GROUP(super) - 1)
/ EXT2_BLOCKS_PER_GROUP(super);
- if (fs->group_desc_count == 0)
- return EXT2_ET_TOOSMALL;
+ if (fs->group_desc_count == 0) {
+ retval = EXT2_ET_TOOSMALL;
+ goto cleanup;
+ }
fs->desc_blocks = (fs->group_desc_count +
EXT2_DESC_PER_BLOCK(super) - 1)
/ EXT2_DESC_PER_BLOCK(super);
@@ -244,15 +279,29 @@
super->s_free_inodes_count = super->s_inodes_count;
/*
+ * check the number of reserved group descriptor table blocks
+ */
+ if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE)
+ rsv_gdt = calc_reserved_gdt_blocks(fs);
+ else
+ rsv_gdt = 0;
+ set_field(s_reserved_gdt_blocks, rsv_gdt);
+ if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) {
+ retval = EXT2_ET_RES_GDT_BLOCKS;
+ goto cleanup;
+ }
+
+ /*
* Overhead is the number of bookkeeping blocks per group. It
* includes the superblock backup, the group descriptor
* backups, the inode bitmap, the block bitmap, and the inode
* table.
- *
- * XXX Not all block groups need the descriptor blocks, but
- * being clever is tricky...
*/
- overhead = (int) (3 + fs->desc_blocks + fs->inode_blocks_per_group);
+
+ overhead = (int) (2 + fs->inode_blocks_per_group);
+
+ if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
+ overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
/* This can only happen if the user requested too many inodes */
if (overhead > super->s_blocks_per_group)
diff --git a/lib/ext2fs/res_gdt.c b/lib/ext2fs/res_gdt.c
new file mode 100644
index 0000000..727b826
--- /dev/null
+++ b/lib/ext2fs/res_gdt.c
@@ -0,0 +1,176 @@
+/*
+ * res_gdt.h --- reserve blocks for growing the group descriptor table
+ * during online resizing.
+ *
+ * Copyright (C) 2002 Andreas Dilger
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include "ext2_fs.h"
+#include "ext2fs.h"
+
+/*
+ * This code assumes that the reserved blocks have already been marked in-use
+ * during ext2fs_initialize(), so that they are not allocated for other
+ * uses before we can add them to the resize inode (which has to come
+ * after the creation of the inode table).
+ */
+errcode_t ext2fs_create_resize_inode(ext2_filsys fs)
+{
+ errcode_t retval, retval2;
+ struct ext2_super_block *sb;
+ struct ext2_inode inode;
+ __u32 *dindir_buf, *gdt_buf;
+ int rsv_add;
+ unsigned long long apb, inode_size;
+ blk_t dindir_blk, rsv_off, gdt_off, gdt_blk;
+ int dindir_dirty = 0, inode_dirty = 0;
+
+ EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+ sb = fs->super;
+ if (!sb->s_reserved_gdt_blocks)
+ return 0;
+
+ retval = ext2fs_get_mem(2 * fs->blocksize, (void **)&dindir_buf);
+ if (retval)
+ goto out_free;
+ gdt_buf = (__u32 *)((char *)dindir_buf + fs->blocksize);
+
+ retval = ext2fs_read_inode(fs, EXT2_RESIZE_INO, &inode);
+ if (retval)
+ goto out_free;
+
+ /* Maximum possible file size (we donly use the dindirect blocks) */
+ apb = EXT2_ADDR_PER_BLOCK(sb);
+ rsv_add = fs->blocksize / 512;
+ if ((dindir_blk = inode.i_block[EXT2_DIND_BLOCK])) {
+ printf("reading GDT dindir %u\n", dindir_blk);
+ retval = io_channel_read_blk(fs->io, dindir_blk, 1, dindir_buf);
+ if (retval)
+ goto out_inode;
+ } else {
+ blk_t goal = 3 + sb->s_reserved_gdt_blocks +
+ fs->desc_blocks + fs->inode_blocks_per_group;
+
+ retval = ext2fs_alloc_block(fs, goal, 0, &dindir_blk);
+ if (retval)
+ goto out_free;
+ inode.i_mode = LINUX_S_IFREG | 0600;
+ inode.i_links_count = 1;
+ inode.i_block[EXT2_DIND_BLOCK] = dindir_blk;
+ inode.i_blocks = rsv_add;
+ memset(dindir_buf, 0, fs->blocksize);
+#ifdef RES_GDT_DEBUG
+ printf("allocated GDT dindir %u\n", dindir_blk);
+#endif
+ dindir_dirty = inode_dirty = 1;
+ inode_size = apb*apb + apb + EXT2_NDIR_BLOCKS;
+ inode_size *= fs->blocksize;
+ inode.i_size = inode_size & 0xFFFFFFFF;
+ inode.i_size_high = (inode_size >> 32) & 0xFFFFFFFF;
+ if(inode.i_size_high) {
+ sb->s_feature_ro_compat |=
+ EXT2_FEATURE_RO_COMPAT_LARGE_FILE;
+ }
+ inode.i_ctime = time(0);
+ }
+
+ for (rsv_off = 0, gdt_off = fs->desc_blocks,
+ gdt_blk = sb->s_first_data_block + 1 + gdt_off;
+ rsv_off < sb->s_reserved_gdt_blocks;
+ rsv_off++, gdt_off++, gdt_blk++) {
+ unsigned int three = 1, five = 5, seven = 7;
+ unsigned int grp, last = 0;
+ int gdt_dirty = 0;
+
+ gdt_off %= apb;
+ if (!dindir_buf[gdt_off]) {
+ /* FIXME XXX XXX
+ blk_t new_blk;
+
+ retval = ext2fs_new_block(fs, gdt_blk, 0, &new_blk);
+ if (retval)
+ goto out_free;
+ if (new_blk != gdt_blk) {
+ // XXX free block
+ retval = -1; // XXX
+ }
+ */
+ gdt_dirty = dindir_dirty = inode_dirty = 1;
+ memset(gdt_buf, 0, fs->blocksize);
+ dindir_buf[gdt_off] = gdt_blk;
+ inode.i_blocks += rsv_add;
+#ifdef RES_GDT_DEBUG
+ printf("added primary GDT block %u at %u[%u]\n",
+ gdt_blk, dindir_blk, gdt_off);
+#endif
+ } else if (dindir_buf[gdt_off] == gdt_blk) {
+ printf("reading primary GDT block %u\n", gdt_blk);
+ retval = io_channel_read_blk(fs->io,gdt_blk,1,gdt_buf);
+ if (retval)
+ goto out_dindir;
+ } else {
+ printf("bad primary GDT %u != %u at %u[%u]\n",
+ dindir_buf[gdt_off], gdt_blk,dindir_blk,gdt_off);
+ retval = -1; // XXX
+ goto out_dindir;
+ }
+
+ while ((grp = ext2fs_list_backups(fs, &three, &five, &seven)) <
+ fs->group_desc_count) {
+ blk_t expect = gdt_blk + grp * sb->s_blocks_per_group;
+
+ if (!gdt_buf[last]) {
+#ifdef RES_GDT_DEBUG
+ printf("added backup GDT %u grp %u@%u[%u]\n",
+ expect, grp, gdt_blk, last);
+#endif
+ gdt_buf[last] = expect;
+ inode.i_blocks += rsv_add;
+ gdt_dirty = inode_dirty = 1;
+ } else if (gdt_buf[last] != expect) {
+ printf("bad backup GDT %u != %u at %u[%u]\n",
+ gdt_buf[last], expect, gdt_blk, last);
+ retval = -1; // XXX
+ goto out_dindir;
+ }
+ last++;
+ }
+ if (gdt_dirty) {
+#ifdef RES_GDT_DEBUG
+ printf("writing primary GDT block %u\n", gdt_blk);
+#endif
+ retval = io_channel_write_blk(fs->io,gdt_blk,1,gdt_buf);
+ if (retval)
+ goto out_dindir;
+ }
+ }
+
+out_dindir:
+ if (dindir_dirty) {
+ retval2 = io_channel_write_blk(fs->io, dindir_blk,1,dindir_buf);
+ if (!retval)
+ retval = retval2;
+ }
+out_inode:
+ printf("inode.i_blocks = %u, i_size = %u\n", inode.i_blocks,
+ inode.i_size);
+ if (inode_dirty) {
+ inode.i_atime = inode.i_mtime = time(0);
+ retval2 = ext2fs_write_inode(fs, EXT2_RESIZE_INO, &inode);
+ if (!retval)
+ retval = retval2;
+ }
+out_free:
+ ext2fs_free_mem((void **)&dindir_buf);
+ return retval;
+}
+
diff --git a/lib/ext2fs/sparse.c b/lib/ext2fs/sparse.c
new file mode 100644
index 0000000..90b028f
--- /dev/null
+++ b/lib/ext2fs/sparse.c
@@ -0,0 +1,78 @@
+/*
+ * sparse.c --- find the groups in an ext2 filesystem with metadata backups
+ *
+ * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
+ * Copyright (C) 2002 Andreas Dilger.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ */
+
+#include <stdio.h>
+
+#include "ext2_fs.h"
+#include "ext2fsP.h"
+
+static int test_root(int a, int b)
+{
+ if (a == 0)
+ return 1;
+ while (1) {
+ if (a == 1)
+ return 1;
+ if (a % b)
+ return 0;
+ a = a / b;
+ }
+}
+
+int ext2fs_bg_has_super(ext2_filsys fs, int group_block)
+{
+ if (!(fs->super->s_feature_ro_compat &
+ EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER))
+ return 1;
+
+ if (test_root(group_block, 3) || (test_root(group_block, 5)) ||
+ test_root(group_block, 7))
+ return 1;
+
+ return 0;
+}
+
+/*
+ * Iterate through the groups which hold BACKUP superblock/GDT copies in an
+ * ext3 filesystem. The counters should be initialized to 1, 5, and 7 before
+ * calling this for the first time. In a sparse filesystem it will be the
+ * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
+ * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
+ */
+unsigned int ext2fs_list_backups(ext2_filsys fs, unsigned int *three,
+ unsigned int *five, unsigned int *seven)
+{
+ unsigned int *min = three;
+ int mult = 3;
+ unsigned int ret;
+
+ if (!(fs->super->s_feature_ro_compat &
+ EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
+ ret = *min;
+ *min += 1;
+ return ret;
+ }
+
+ if (*five < *min) {
+ min = five;
+ mult = 5;
+ }
+ if (*seven < *min) {
+ min = seven;
+ mult = 7;
+ }
+
+ ret = *min;
+ *min *= mult;
+
+ return ret;
+}